• WVDP 1

DECOMMISSIONING PLAN
WVDP PHASE 1 DECOMMISSIONING
•
consideration of
The conceptual
conceptual model for streambed
streambed sediment was developed
developed after consideration
streams, plausible future land uses
how residual radioactivity enters and moves though the streams,
uses
valleys, how humans might be exposed
for the stream valleys,
exposed to residual contamination
contamination in the
the
streams or on the banks,
banks, and plausible habits of a person who might spend time at the
the
conceptual model
future . Such considerations led to selection of a conceptual
streams in the future.
appropriate
determined to be an appropriate
RESRAD. The RESRAD code was determined
compatible with RESRAD.
mathematical
extensive use in evaluating
evaluating potential doses from
from
mathematical model
model based
based on its extensive
subsurface soil DCGL
surface soil and its use in the surface
surface soil DCGL and subsurface
radioactivity in surface
radioactivity
models
models for this project.
As shown in Figure 55-10,
10, the contamination zone
zone was assumed
assumed to be on the stream
conditions
bank rather than in the stream itself. This model is consistent with typical conditions
Frank's Creek downstream
downstream of the Lagoon 3 outfall as shown by the
the
observed along Frank's
radiological
radiological control area in Figure 5-11
5- 11 represented
represented by the roped-off area.
area . ItIt is conservative
conservative
compared to having
having the contamination
contamination zone in the stream itself where water would act as
as
compared
shielding
shielding to reduce the direct
direct radiation dose.
dose .
The photograph in Figure 5-11 was taken from just inside the project premises
premises security
fence looking upstream toward the southwest. The confluence
confluence with Erdman Brook lies
lies
about 200 feet upstream
upstream from where the people are standing and the Lagoon 3 outfall is
about 500 feet from where the people
people are standing.
standing .
•
5-11. Franks Creek Looking Upstream (2008 WVDP photo)
Figure 5-11.
conceptual model
Key features
features of this conceptual
model include
include the following:
following :
•*
•
Revision 2
Revision
purposes was
A person
person spending
spending time in the area of the streams for recreation purposes
determined to be the appropriate
appropriate member
member of the critical group; the area is not
suitable for farming,
livestock
grazing,
farming ,
grazing, or residential
residential use because
because of the steep
5-35
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WVDP PHASE
PHASE 11 DECOMMISSIONING
DECOMMISSIONING PLAN
PLAN
WVDP
stream
stream banks,
banks , especially
especially considering
considering further
further erosion
erosion that
that is likely
likely to
to occur
occur as
as
discussed previously.
previously.
discussed
*•
In
In this exposure
exposure scenario
scenario the
the primary
primary radiation
radiation source
source is
is considered
considered as
as the
the
on the
the stream
stream bank.
bank. The ability
ability of sediment
sediment to adsorb
adsorb and
and
sediment deposited
deposited on
sediment
dilute species
species of
of
absorb radionuclides
radionuclides would
would be expected
expected to
to concentrate
concentrate otherwise
otherwise dilute
absorb
ions
ions from the
the water
water (NRC
(NRC 1977).
1977). The
The water
water in
in the stream
stream provides
provides some shielding
shielding
and
from radionuclides
radionuclides in
in sediments
sediments on
on the stream
stream bottom,
bottom, thus
thus
and separation
separation from
11
ingestion pathways
reducing
reducing direct exposure
exposure and incidental
incidental ingestion
pathways from those sources."
sources.
*•
The
located on
The hypothetical
hypothetical recreationist
recreationist is assumed
assumed to be
be located
on the contaminated
contaminated
stream bank for 104
104 hours per year,
year, which
which could involve spending
spending two
two hours
hours per
per
day, two days
days per week
week for 26
26 weeks
weeks aa year,
year, reasonable
reasonable assumptions
assumptions considering
considering
day,
the
the local
local climate.
climate.
*•
located on the stream bank and is assumed
to
The contaminated
assumed to
contaminated zone
zone of interest
interest is located
be three
three meters
meters (10 feet) wide and 333 meters
meters (1093
(1093 feet) long,
long , with a total area
area of
Y.. acre).
1000 square meters
meters (approximately
(approximately ¼
1000
*•
contaminated zone on the stream
Having
Having the
the contaminated
stream bank takes into account
account aa situation
situation
where the
the stream level might rise
rise significantly
significantly then fall again to a lower
lower level.
•
The hypothetical
recreationist is assumed
hypothetical recreationist
assumed to eat venison from deer whose flesh is
contaminated
radioactivity
from
contaminated
with
contaminated
radioactivity
contaminated stream banks, such
such as from
grazing on grass,
grass, and
and ingesting
ingesting stream water.
water.
Consideration
Consideration was given to both receptor location and stream bank
bank geometry.
Potential doses to a recreationist from impacted stream
stream water will be less
less significant
significant
than potential doses
doses from the stream
stream bank for the following reasons:
reasons :
"•
It would be plausible for the hypothetical
It
hypothetical recreationist
recreationist to spend more time on the
the
stream bank than immersed in stream water;
water;
•*
The water would provide radiation
radiation shielding for radioactivity in the streambed
radiation;;
sediment, which wou
ld decrease
potential dose from direct
direct radiation
would
decrease potential
sediment,
•*
While
stream bank,
bank, the external dose from surface water would be
be
While on the stream
source; and
compared with the dose from the stream
negligible compared
stream bank source;
•*
Neglecting erosion of the stream bank source leads to greater
Neglecting
greater doses than
streambed,, where
considering erosion of the source from the stream bank to the streambed
significant shielding from surface
surface water would reduce the dose.
•
•
The stream bank geometry was assumed to be represented by a plane source of
bank. Potential doses from alternative source
contamination along the stream bank.
contamination
source
reasons::
in this evaluation for the following reasons
configurations were not included in
the stream
stream itself
itself would
in the
Note that modeling of transport,
transport, deposition, and concentrations
concentrations of radionuclides in
would
involve consideration
consideration
decommissioning, and
and involve
Phase 11 of
of the
the decommissioning,
on potential
potential releases
releases after Phase
require assumptions
assumptions on
require
time..
not considered at this time
end-state, factors which are appropriately not
of the Phase 2 end-state,
11
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•
WVDP PHASE 1 DECOMMISSIONING
DECOMMISSIONING PLAN
•
*•
in doses similar
Any dose variation
variation due to a sloped stream bank would likely result in
movement of the receptor and exposure
exposure to an equivalent
equivalent
to level sources
sources due to movement
assumed to spend time moving
the
moving throughout the
uniform dose
dose (e.g. receptor
receptor is assumed
source area
area and facing all directions for equal amounts of time);
*•
Although exposure
exposure to a source
source area wider than several meters is unlikely
unlikely
assumed to be externally
externally exposed to
considering the steep terrain, the receptor
receptor is assumed
conservatism; and
a circular infinite plane
plane source
source for conservatism;
•*
the
Because the mass balance
balance model was used for the sediment
sediment calculations, the
parameter is not used in the calculations for water dependent
dependent
source width parameter
pathways.
All of the input parameters
parameters for development
development of the streambed sediment DCGLs appear
appear
in Appendix
in
Appendix C. Table 5-7 identifies selected key input parameters.
Parameters for Streambed
Development(')
Streambed Sediment DCGL Development(1)
Table 5-7. Key Input Parameters
J ·Value
Value
Parameter (Units)
Area of contaminated
(M
contaminated zone (m
•
2
Basis
Basis
1.0E+03
1.0E+03
Area on stream bank.
Thickness
contaminated zone (m)
Thickness of contaminated
(m)
1.0E+00
Conservative assumption.
Fraction of year spent outdoors
outdoors
1.2E-02
1.2E-02
104 hours (out of a total of
104
in
8760 hours per year) in
area.
Cover
(m)
Cover depth (m)
0
Contamination on surface.
Contamination
(m/y)
rate (m/y)
Contaminated zone erosion rate
Contaminated
0
0
Conservative assumption.(2)
Conservative
assumption. (2)
Well pump intake depth (m below water
water table)
0
Only applicable
applicable to farming.
Well pumping rate (m /y)
0
Only applicable
applicable to farming.
Unsaturated zone thickness (m)
Unsaturated
0
Contamination on stream
surface.
bank surface.
))
3
coefficient for
Contaminated
Contaminated zone distribution coefficient
strontium
(mL/g)
strontium (mUg)
1.5E+01
1.5E+01
See Table C-2.
Contaminated zone distribution coefficient
coefficient for
cesium (mUg)
(mL/g)
4.8E+02
4.8E+02
See Table
Table C-2.
distribution coefficient
Contaminated zone distribution
coefficient for
(mL/g)
americium (mUg)
4.OE+03
4.0E+03
See Table
Table C-2.
NOTES: (1)
normally
NOTES:
(1) See Appendix
Appendix C for other input parameters.
parameters. Metric units are used here because they are normally
in RESRAD.
used in
(2)
conservative because
in no erosion
erosion of the
the source.
source.
(2) This assumption is conservative
because it
it results in
In development
development of the conceptual
conceptual model,
model, consideration
consideration was given to protection
protection of
environmental and ecological resources, as well as human health. ItIt was determined that
environmental
•
Revision 2
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WVDP
WVDP PHASE
PHASE 1
1 DECOMMISSIONING
DECOMMISSIONING PLAN
PLAN
changes to
to the
the model
model or the radioactivity
radioactivity cleanup
cleanup criteria
criteria will
will be necessary
necessary for
for this
this
no changes
12
12
purpose.
5.2.4
5.2.4
Mathematical
Mathematical Model
Model
As
noted previously,
As noted
previously, RESRAD
RESRAD (Yu,
(Yu, et
et al.
al. 2001)
2001) is
is used
used as
as the
the mathematical
mathematical model
model for
mrem/y per
DCGL development.
development. Version
Version 6.4
6.4 was
was used to calculate
calculate the unit
unit dose
dose factors (in mrem/y
of the
the 18
18 radionuclides
each of
of the
the three
three exposure
exposure scenarios. Unit
Unit dose
dose
pCi/g) for each
each of
radionuclides in each
pCi/g)
factors
factors were
were then scaled
scaled in Microsoft
Microsoft Excel
Excel to calculate
calculate individual
individual radionuclide
radionuclide DCGLs
DCGLs
corresponding to 25 mrem
mrem per year.
corresponding
•
RESRAD was
RESRAD
was selected
selected as the mathematical
mathematical model for DCGL development
development due to the
the
extensive use by DOE and
and by NRC
NRC licensees
licensees in evaluating
evaluating doses from residual
extensive
considers multiple
radioactivity
radioactivity at decommissioned
decommissioned sites. The RESRAD
RESRAD model
model considers
multiple exposure
pathways for direct contact
contact with
with radioactivity,
radioactivity, indirect
indirect contact, and
and food uptake,
uptake, which are
are
pathways
evaluated at the WVDP.
the conditions being evaluated
post-Phase 1 conceptual
RESRAD
RESRAD was
was used with the post-Phase
conceptual models described
described previously to
radionuclide source concentrations
concentrations (i.e.,
generate
generate doses for unit radionuclide
(Le., dose per pCi/g of source).
to
The resulting
resulting doses
doses were
were then scaled to the limiting acceptable
acceptable dose (25 mrem
mrem in aa year) to
radionuclide specific DCGLs (see Appendix
provide
maximum
provide the radionuclide
Appendix C). For example, the maximum
determined to be 1.7
estimated
Cs-137 in surface
surface soil was
was determined
estimated annual dose from 1 pCi/g of Cs-137
mrem, so the DCGL for 25 mrem per year is 25 divided
divided by 1.7
1.7 or 14.8
14.8 pCi/g prior
prior to
accounting
accounting for decay
decay (see Table C-5). The calculated
calculated DCGLs were then
then input
input into the
the
concentration to verify
model
model as the source
source concentration
verify that the dose
dose limit of 25 mrem per year
year was not
exceeded.
post-Phase 1
application of RESRAD to the post-Phase
Among the general considerations
considerations for the application
decommissioning conceptual models were:
decommissioning
12
•*
the
surface soil due to the
groundwater pathways model for surface
Use of the non-dispersion groundwater
relatively large source area;
•*
balance model, instead of the less conservative
conservative non-dispersion
non-dispersion
Use of the mass balance
model, for the subsurface
sediment models due to the relatively
relatively
subsurface and streambed sediment
small source
source areas;
areas; and
and
•
DOE Order 450.1, Environmental ProtectionProgram,requires that DOE Environmental Management
12 DOE Order 450.1, Environmental Protection Program, requires that DOE Environmental Management
of the
the air,
air,
management system to ensure protection of
have an environmental
facilities such as the WVDP have
environmental management
environmental; public
public
resources in
in compliance with applicable environmental;
water, land, and other natural and cultural resources
includes
Implementing guidance
resource protection laws, regulations, and DOE requirements. Implementing
health; and resource
guidance includes
and Terrestrial
Terrestrial
Doses to
to Aquatic
Aquatic and
for Evaluating
Radiation Doses
A Graded
GradedApproach
Approach for
DOE Standard
Standard 1153-2002,
1153-2002, A
DOE
Evaluating Radiation
ecological
to evaluate
potential adverse ecological
concentration guides
guides to
biota concentration
Biota. This guidance
guidance includes the use of biota
Biota.
evaluate potential
radionuclides.
effects from exposure to radionuclides.
in relation
doses to aquatic and riparian animals and plants in
potential annual doses
evaluates potential
The WVDP routinely evaluates
radionuclide
RESRAD-BIOTA computer code (DOE 2004) and radionuclide
to the biota concentration guides using the RESRAD-BIOTA
with the
the
These evaluations show compliance with
inwater and streambed sediment. These
concentrations measured in
environmental monitoring and control program for Phase 11 of the
URS 2009). The environmental
guides (WVES and URS
Order 450.1
450.1 during
during the
the
with DOE
DOE Order
1.8 would
would ensure
ensure compliance
compliance with
in Section 1.8
decommissioning described in
decommissioning activities.
Revision 2
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•
WVDP PHASE 1 DECOMMISSIONING
DECOMMISSIONING PLAN
•
•*
The conservative
conservative assumption
the
assumption of no erosion
erosion for soil and sediment sources
sources in
in the
development
development of DCGLs,
DCGLs, so there will be no source depletion from erosion.
The RESRAD
RESRAD model has limitations in this application
application in that it was developed
developed for soil
exposures and therefore does
does not specifically
specifically address certain transport mechanisms
mechanisms
exposures
associated
associated with sediment,
sediment, such as:
•"
Periodic saturation of the contaminated zone located
located along a stream
stream bank flood
zone;
zone;
•*
Erosion/scour of stream bank material
material and subsequent
subsequent downstream
downstream deposition
deposition to
to
the stream-bottom;
stream-bottom;
•*
from
Deposition of clean material onto the stream bank,
bank, transported
transported downstream
downstream from
unimpacted upstream locations;
*•
Variability
concentrations due to fluctuation in flow rates during
water concentrations
during
Variability in surface water
storm events;
"
•
Partitioning of contaminants between the surface water and stream-bottom
stream-bottom
sediment; and
*•
Variability
moisture
Variability of airborne
airborne dust loads due to varying stream bank sediment moisture
content.
To address the simplifications
model,, and still retain conservatism in
simplifications of the conceptual model
results,, the following assumptions
model:
the results
assumptions were made for the sediment model:
•
*•
The model will not allow the contaminated
contaminated zone to be below the water table (as
(as
may periodically happen to the stream bank), therefore it was assumed
that
there
assumed
was no unsaturated
unsaturated zone, and that the water table exists immediately
immediately below the
the
source;
source;
•*
conservatively selected
selected to reflect soil on a
The inhalation parameter
parameter values were conservatively
farm,, although stream bank sediment is likely to result in lower respirable
farm
respirable dust
loadings;
loadings;
•"
Contaminated groundwater
discharge to the stream, where
where itit is
Contaminated
groundwater is assumed to discharge
impounded
and
contributes
to
fish
bioaccumulation;
impounded
contributes
bioaccumulation;
•*
Fish ingested from the stream are large enough to provide a significant number of
meals each year, but are assumed
assumed to only be exposed
exposed to contaminated
contaminated water and
never swim to uncontaminated
uncontaminated sections of the stream;
stream; and
•*
In addition to assuming the fish are never
In
never in clean
assumed
assumed to eat only fish that are contaminated
contaminated when,
not support fish at all at the present time owning to
typically present as shown in Figure
Figure 5-11.
5-11 .
water, the recreationist is
in actuality,
actuality, the stream will
the small amount of water
represents plausible conditions on the stream
The conceptual
conceptual model just described
described represents
banks and in the streambeds.
It
is
considered
in
streambeds. It
considered to be aa valid model for the long term in
support of a Phase
unrestricted release
release,, that is,
is, the site-wide removal
Phase 2 strategy involving unrestricted
alternative
EIS. However, it would not necessarily serve as aa valid
alternative in the Decommissioning EIS.
•
Revision
Revision 2
5-39
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DECOMMISSIONING PLAN
WVDP PHASE 1 DECOMMISSIONING
model ifif the Phase 2 sources were to be closed in place,
place, as with the site-wide close-inalternative.
place alternative.
accounting for processes
This limitation results from the model not accounting
processes that could impact
site-wide close-in-place
close-in-place alternative.
alternative. For example,
example,
the streams in the future under the site-wide
unchecked erosion in
impacts on the streams could
could occur in the long term from unchecked
in the
the
areas, and increased
radioactive waste disposal areas,
areas, surface
surface water runoff from eroded areas,
include
seepage of contaminated groundwater
streams. Such impacts could include
groundwater into the streams.
in
increases
increases in radionuclide concentrations in water in the streams as well as increases in
contamination
contamination in the sediment.
•
This limitation would be considered
considered in any decision made by DOE to remediate
remediate
banks. Such remediation
Phase 1
remediation during Phase
sediment in the streams and on the stream banks.
decommissioning
decommissioning activities
activities would require
require a revision to this plan.
plan .
RESRAD input parameters
parameters were
were selected from the following sources, generally in the
the
order given
based
on
availability:
given
•*
Site-specific
available, (e.g. groundwater
groundwater and vadose zone
zone
Site-specific values
values where available,
parameters
parameters such as the distribution coefficients
coefficients listed in Table 3-20);
•*
Semi site-specific
literature values, (e.g.
from
site-specific literature
(e.g . physical
physical values based on soil type from
data
and
behavioral
factors
based
on
regional
NUREG/CR-6697
(Yu,
et
al.
2000)
NUREG/CR-6697
based
Exposure Factors
Handbook (EPA
in the U.S. Environmental
Environmental Protection
Protection Agency's Exposure
Factors Handbook
1997);
•*
Scenario-specific values using conservative
Scenario-specific
conservative industry defaults, (e.g., from the
the
Exposure Factors
Factors Handbook,
Exposure
Handbook, the RESRAD
RESRAD Data
Data Collection
Collection Handbook
Handbook (Yu, et al.
NUREG/CR-5512, Volume
1993), NUREG/CR-6697
NUREG/CR-6697 (Yu, et al. 2000), and NUREG/CR-5512,
Volume 3
(Beyeler,
(8eyeler, et al. 1999);
•*
parameters defined by aa
The most likely values among default RESRAD parameters
NUREG/CR-6697 (Yu, et
distribution, when available, otherwise mean values from NUREG/CR-6697
distribution,
al. 2000).
5.2.5
5.2.5
•
Results
Summary of Results
Summary
Table 5-8 provides
provides the calculated individual
individual radionuclide
radionuclide DCGLs for surface
surface soil,
average
subsurface
subsurface soil, and streambed
streambed sediment
sediment which assure that the dose to the average
the
dose
exceed
25
mrem
per
year
when
considering
member
of
the
critical
group
will
not
member
radionuclide individually. Note that the surface soil DCGLs apply
contribution
contribution from each radionuclide
subsurface soil contamination and
only to areas of the project premises where
where there is no subsurface
that the subsurface
subsurface soil DCGLs apply only to the bottoms and lower sides (extending
(extending from
from
a depth of three feet and greater) of the large excavations in WMA 1 and WMA 2.
2.
Table 5-8. DCGLs For 25 mrem
pCi/g)(1)
mrem Per Year (DCGLw
(DCGLw Values in pCilg)(1)
Nuclide
Surface
Surface Soil
Subsurface Soil(3)
Subsurface
Streambed
Sediment
Streambed Sediment
Am-241
4.3E+01
7.1 E+03
7.1E+03
1.6E+04
1.6E+04
C-14
2.OE+01
2.0E+01
3.7E+05
3.7E+05
3.4E+03
3.4E+03
Revision
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•
WVDP PHASE 1 DECOMMISSIONING
DECOMMISSIONING PLAN
•
•
5-8. DCGLs For 25 mrem Per Year (DCGLw
Table 5-8.
(DCGLw Values in pCi/g)(1)
Nuclide
Surface
Surface Soil
Subsurface
Subsurface Soil(3)
Soil(3)
Streambed
Streambed Sediment
Sediment
Cm-243
4.1E+01
1.2E+03
1.2E+03
3.6E+03
3.6E+03
Cm-244
8.2E+01
8.2E+01
2.3E+04
4.8E+04
Cs-137(2)
2.4E+01
2.4E+01
4.4E+02
4.4E+02
1.3E+03
1.3E+03
1-129
1
-129
3.5E-01
3.5E-01
5.2E+01
3.7E+03
3.7E+03
Np-237
9.4E-02
9.4E-02
4.3E+00
4.3E+OO
5.2E+02
5.2E+02
Pu-238
5.0E+01
1.5E+04
1.5E+04
2.OE+04
2.0E+04
Pu-239
4.5E+01
1.3E+04
1.8E+04
Pu-240
4.5E+01
1.3E+04
1.3E+04
1.8E+04
Pu-241
1.4E+03
2.4E+05
5.1
E+05
5.1E+05
Sr-90(2)
Sr-90(2)
6.3E+00
6.3E+OO
3.2E+03
9.5E+03
9.5E+03
Tc-99
Tc-99
2.4E+01
1.1 E+04
1.1E+04
2.2E+06
2.2E+06
U-232
5.8E+00
5.8E+OO
1.OE+02
1.0E+02
2.6E+02
2.6E+02
U-233
1.9E+01
1.9E+01
1.9E+02
5.7E+04
5.7E+04
U-234
2.OE+01
2.0E+01
2.OE+02
2.0E+02
6.0E+04
6.0E+04
U-235
1.9E+01
1.9E+01
2.1
2.1E+02
E+02
2.9E+03
2.9E+03
U-238
U-238
2.1E+01
2.1E+01
2.1E+02
1.2E+04
1.2E+04
NOTES:
in
NOTES : (1) Refer to Sections
Sections 5.2.7 and 5.2.8
5.2.8 for discussions about how this
th is set of DCGLs was considered
considered in
establishing
establishing cleanup goals.
goals.
(2) Sr-90 and Cs-137 DCGLs reflect
reflect 30 years
years of decay and apply to the year 2041 and later.
models.
(3) The
The lower deterministic DCGL of the resident farmer and residential gardener conceptual
conceptual models.
As noted previously,
sum-of-fractions rule will be applied if
characterization data
previously, the sum-of-fractions
if characterization
indicate that a mixture of radionuclides
radionuclides is present
present in an area.
area .
indicate
Conclusions About Results
Results
simulations are presented
presented in Appendix C.
C. For surface
surface
Detailed outputs of the RESRAD simulations
soil,
the
results
show
that:
soil ,
•"
Am-241 doses are due primarily
primarily to ingestion of plants,
•"
Cs-137 doses
exposure, and
doses are due primarily to external exposure,
•"
Sr-90 doses are due primarily to ingestion of plants.
plants.
The modeling to develop
subsurface soil DCGLs indicated that:
develop the subsurface
*•
Am-241 doses are due primarily to external exposure
exposure and ingestion of impacted
plants,
plants,
*•
Cs-1 37 doses
external exposure,
exposure,
Cs-137
doses are due primarily to external
"
•
Sr-90 doses are due primarily to ingestion of impacted
impacted plants and water, and
*•
subsurface soil are greater
greater than those for the surface
surface soil.
DCGLs for subsurface
The modeling to develop the streambed sediment DCGLs indicated that:
that:
•
Revision 2
5-41
WVDP
WVDP PHASE 1 DECOMMISSIONING
DECOMMISSION ING PLAN
•*
incidental ingestion of sediment
Am-241 doses are due primarily to incidental
sed iment and to external
exposure,
exposure,
•*
external exposure,
Cs-137 doses are due primarily to external
exposure, as well as ingestion of
venison,
venison,
•"
Sr-90 doses are due primarily to ingestion
ingestion of venison, and
•"
DCGLs for the sediment
sediment source are orders of magnitude
magnitude greater than those for
surface soil.
I
•
Conservatism
Calculations
Conservatism in Calculations
A number of factors make the DCGLs calculated
base-case model
calculated using the initial base-case
conservative.
DCGLs, these factors include,
include, for example,
example, the relatively
conservative. For the surface
surface soil DCGLs,
short local growing season
season,, which makes it
it likely that crop and forage yields will be less
less
than those assumed for the site.
subsurface soil DCGLs,
DCGLs, conservative
For the subsurface
conservative factors include:
•*
the
hypothetical well (cistern) used in the
As discussed
discussed previously, the diameter of the hypothetical
initial base-case
base-case model at two meters (about 6.6 feet) is much larger
the
larger than the
13
diameter of a typical water well (eight inches) 13..
*•
Use of the mass balance
in that all
balance model within RESRAD is conservative
conservative in
leachate reaches
reaches the intake well.
radionuclide inventory
inventory in leachate
*•
Because of the relatively short local
local growing season,
season , itit is likely that crop/forage
crop/forage
site.
yields will be less than those assumed for the site.
DCGLs, conservative
conservative factors include:
For the streambed sediment DCGLs,
•
Based on limited available data, the typical thickness of the contaminated
contaminated zone is
likely smaller than the one meter (about 3.3 feet) value used
used in the analysis.
analysis.
"
•
contamination will be found in the stream beds,
beds, not
data, most contamination
Based on available data,
on the banks.
banks.
"
•
It is unlikely that the incidental
incidental ingestion rate (50 mg/d) for sediment will be
It
be
contaminated area.
exclusively from the contaminated
"
•
It is assumed
recreationist are impacted
impacted by the
It
assumed that all fish ingested by the recreationist
the
source; however,
however, itit is more likely that aa recreationist may
streambed sediment source;
ingest fish from other locations as well.
*•
Similarly, it is unlikely that the venison ingested will be impacted by streambed
sediment
sediment sources exclusively.
exclusively. ItIt is more likely that exposure will be from both
areas.
impacted and non-impacted
non-impacted areas.
•
With the larger diameter, much more contaminated soil and residual radioactivity would be brought to the
With the larger diameter, much more contaminated soil and residual radioactivity would be brought to the
surface where
exposure through
through various
pathways. The
The difference
in volume
volume would
would vary
vary with
with
surface
where itit could
could cause
cause exposure
various pathways.
difference in
the
square of
of the
much contaminated
soil would
surface in
inthe
the radius;
radius; 100
100 times
times as
as much
contaminated soil
would be
be brought
brought to
to the
the surface
the
the square
conceptual model with
with the
the two meter diameter
diameter well
well than
than with aa model
that assumed
assumed a 20 centimeter
(eight
conceptual
model that
centimeter (eight
inch) diameter
The larger
assumed ensures
pumping needs
of the
the residential
inch)
diameter well.
well. The
larger diameter
diameter well
well assumed
ensures that
that the
the pumping
needs of
residential
farm would be met, since a smaller diameter well could not do this on some parts of the project premises.
premises.
13
13
Revision 2
5-42
•
WVDP PHASE 1 DECOMMISSIONING
DECOMMISSIONING PLAN
•
•
Assumptions regarding the availability
availability of an adequate
adequate fish population to allow
allow long
long
term fish ingestion
ingestion may also result in overestimation
overestimation of doses
doses related to the
the
sediment source,
there are currently
currently no fish in
in the streams
streams of sufficient quality or
source, as there
quantity for sustained human
human consumption.
DCGLs
Applicability of Streambed Sediment
Sediment DCGLs
The conceptual model used for developing
developing DCGLs for stream
stream bed sediment in Erdman
Brook and the portion of Franks Creek on the project premises
streams
premises assumed that these streams
banks.. Th
This
parts.
have steep banks
is condition exists in most parts of the streams but not all parts.
Consequently, itit is necessary
necessary to define where the streambed
Consequently,
streambed sediment
sediment DCGLs and cleanup
cleanup
goals apply.
sediment DCGLs and cleanup
Figure 5-12 shows the points where the streambed sediment
cleanup
apply. As indicated on the figure,
figure , the surface soil DCGLs and cleanup goals apply
goals apply.
upstream
upstream of these points and to the small tributaries
tributaries to the streams.
streams.
•
/
Streambed sediment cleanup
goals apply downstream of this
point (surface soil cleanup goals
apply upstream).
Figure
5-12. Areas Where Streambed Sediment DCGLs and Cleanup
Cleanup Goals Apply
Figure 5-12.
Apply
•
Revision 2
5-43
5-43
DECOMMISSIONING PLAN
WVDP PHASE 1 DECOMMISSIONING
5.2.6
Analyses
Discussion of Sensitivity
Sensitivity Analyses
Table
performed for the surface soil DCGL
Table 5-9 summarizes
summarizes the sensitivity analyses
analyses performed
base-case
C.
base-case model,
model , which are detailed in Appendix C.
DCGLs(1)
Surface Soil
Parameter Sensitivity Analyses -- Surface
Soil DCGLs(1)
Table 5-9 Summary of Parameter
Parameter
Indoor/Outdoor
Indoor/Outdoor
Fraction
Run
11
Change in
Sensitivity
Parameter
Minimum
Change
Minimum DCGL
DCGL Change
Change
-32%
-32%
-22%
-22%
Nuclide(s)
U-232
Maximum DCGL
DCGL Change
Change
Maximum
Change
0%
0%
Nuclide(s)
11-129
-129
2
21%
21%
0%
1-129 U-234
U-234
28%
28%
3
-50%
-50%
9%
U-232
81%
81%
4
200%
200%
-28%
-28%
U-235
0%
5
-50%
-50%
-3%
U-235
U-235
0%
0%
6
6
150%
150%
0%
12%
12%
Irrigation/Pump
Irrigation/Pump
Rate
7
-57%
-57%
8
8
70%
70%
-1%
-36%
-36%
Cs-1 37 Sr-90
U-232
U-232
U-232
U-232
1-129
1-129
Cs-I137
Cs-137 Sr-90
U-232
U-232
U-235
U-235
65%
65%
1%
1%
1-129
U-232
U-232
Soil/Water
Distribution
Coefficients (Kd)
(I<d)
9
lower
-71%%
-71
U-234
U-234
0%
Cs-137
Cs-1
37
10
10
higher
higher
-3%
-3%
U-232
U-232
867%
867%
U-234
U-234
11
-55%
-36%
-36%
11-129
-1 29
0%
0%
Cs-137 Sr-90
U-232
U-232
12
57%
57%
0%
Cs-137 Sr-90
U-232
U-232
40%
40%
1-129
1-129
13
-23%
-23%
-29%
-29%
U-234
U-234
2%
2%
U-232
U-232
14
15%
15%
-2%
-2%
U-232
79%
79%
1
-1 29
1-129
15
15
-40%
-40%
-40%
-40%
1-129
1-129
0.0%
0.0%
Cs-1 37 Sr-90
Cs-137
Sr-90
U-232
16
16
100%
100%
0%
Cs-1 37 Sr-90
Cs-137
U-232
99%
99%
1-129
1
-129
17
-30%
-30%
0%
Cs-1 37 Sr-90
U-232
U-232
30%
30%
1-129
1-129
18
18
21%
21%
-12%
-12%
1-129
0.0%
0.0%
Cs-i137 Sr-90
Cs-137
U-232
19
19
-33%
-33%
-23%
-23%
1-129
0.0%
0.0%
Cs-i137 Sr-90
Cs-137
Sr-90
U-232
20
33%
33%
0%
Cs-137 Sr-90
U-232
23.3%
23.3%
1-129
1
-1 29
21
-38%
-38%
0%
Cs-1 37 1-129 Sr-90
U-232 U-233
U-234 U-235
U-238
0.0%
0.0%
Cs-137 1-129
1-129
Sr-90 U-232
U-232
U-233 U-234
U-234
U-235 U-238
U-238
Contamination
Zone Thickness
Unsaturated
Zone Thickness
Hydraulic
Hydraulic
Conductivity
Runoff/
Evaporation
Coefficient
Depth of Well
Intake
Length Parallel
Parallel
to Aquifer
Aquifer Flow
Hydraulic
Gradient
Gamma
Shielding Factor
Revision 2
Revision
5-44
5-44
U-235
•
0%
U-232
Sr-gO
Sr-90
Cs-137
Cs-1 37
•
•
DECOMMISSIONING PLAN
WVDP PHASE 11 DECOMMISSIONING
•
1
DCGLs0 '
Soil DCGLs(1)
Surface Soil
Analyses -- Surface
Parameter Sensitivity Analyses
Table 5-9 Summary of Parameter
Parameter
Minimum DCGL
Change
Minimum
DCGL Change
Change
22
87%
87%
-24%
-24%
23
-60%
-60%
24
Nuclide(s)
Nuclide(s)
Maximum
DCGL Change
Maximum DCGL
Change
Change
Nuclide(s)
U-232
0.0%
0.0%
1-129
0%
0%
Cs-137
1-129
Cs-137 1-129
Sr-90 U-234
U-234
0.2%
0.2%
U-232
U-232
-25%
-25%
0%
0%
Cs-137
Cs-1
37 1-129
1-1 29
Sr-90 U-233
U-233
U-234
U-234
0.1%
0.1%
U-232
U-232
25
-70%
0%
0%
Cs-137
1-129
Cs-1
37 1
-1 29
Sr-90 U-234
U-234
0.3%
0.3%
U-232
26
67%
67%
0%
U-232
0.0%
0.0%
Cs-137
Cs-1 37 1-129 Sr90 U-235 U-238
Root Depth
27
27
-67%
-67%
0%
0%
Cs-137 1-129
Cs-137
Sr-90 U-232
U-232
U-233 U-234
U-235 U-238
0.0%
0.0%
Cs-137 1-129
1-129
Cs-137
Sr-90 U-232
U-233 U-234
U-234
U-235 U-238
U-235
U-238
28
29
30
30
233%
233%
Food Transfer
Factors
Factors
lower
higher
higher
0%
-38%
-97%
-97%
1-129
U-235
Sr-90
Sr-90
193.7%
193 .7%
875%
875%
42%
-42%
31
31
NA
-67%
-67%
U-234
0.0%
0.0%
Indoor Dust
Filtration Factor
Filtration
Dust Loading
Factor
Mass Balance
Balance
Model
•
Change
in
Change in
Sensitivity
Parameter
Run
I
Sr-90
Sr-90
U-238
Cs-1 37 Sr-90
Cs-137
U-232
I U-232
contribute significantly
significantly to
to the
here are
are for
radionuclides considered
NOTES: (1
(1)) Results
Results presented
presented here
NOTES:
for radionuclides
considered likely
likely to
to contribute
the overall
overall
characterization data.
surface
surfa
ce soil dose based
based on available
available characterization
data.
Results
Discussion of Surface Soil Results
model been evaluated
The sensitivity analysis results for the surface soil source model
drivers,
i.e.,
that
are
the
primary
dose
considering those radionuclides
radionucl ides
i.e ., those that are likely
likely
characterization data. The
The
available characterization
to contribute significantly
significantly to predicted
predicted dose based on available
uptake), 1-129
1-129 (due to water
radionuclides
radionuclides are Sr-90 (due to water independent
independent plant uptake),
uranium radionuclides
radionuclides
dependent pathways),
dependent
pathways), Cs-137 (external radiation dose), and most uranium
(water dependent
dependent pathways).
pathways).
the
radionuclides, indicates
The sensitivity analysis of the surface
surface soil model,
model , for these radionuclides,
indicates the
following:
following :
lower indoor
indoor exposure
exposure fraction
decrease for U-232.
•" A
A lower
fraction results
results in the largest
largest DCGL decrease
U-232.
Similarly,
fraction results in the largest increase for U-232
Similarly, a higher indoor exposure fraction
U-234. However,
and no change
change for 1-129 and U-234.
However, itit is unlikely that the indoor fraction is
climate.. The U-232
too low based on the local climate
U-232 doses
doses are mainly due to external
exposure,
which
exposure, wh
ich accounts
accounts for the relative sensitivity
sensitivity to this parameter.
Decreasing the
the source
thickness increased
increased the DCGL for all radionucl
radionuclides
•" Decreasing
source thickness
ides and
increasing the source th
thickness
ickness resulted in the most significant
significant DCGL decrease for
parameter is due to increased/decreased
U-235. The sensitivity to this
U-235.
th is parameter
increased/decreased dose from
independent).
the water ingestion and plant pathways
pathways (both water dependent
dependent and independent).
•
Revision 2
Revision
5-45
5-45
WVDP PHASE 1 DECOMMISSIONING
DECOMMISSIONING PLAN
Decreasing the unsaturated
U•" Decreasing
unsaturated zone
zone thickness
thickness resulted in a decreased
decreased DCGL for U235 and produced no change for Cs-137,
1-129,
U-232.. Similarly,
Similarly, increasing the I
Cs-137, 1
- 129, and U-232
unsaturated zone thickness increased the U-235 DCGL and produced
change
unsaturated
produced no change
for Cs-137,
1-129,
and
U-232.
Sensitivity
to
this
parameter
is
mainly
due to
U-232.
Cs- 137, 1-1 29,
increased/decreased travel time of contaminants
contaminants to the saturated zone,
zone, resulting in
increased/decreased
water
water dependent
dependent doses occurring earlier/later
earlier/later with respect to doses
doses from water
independent pathways.
pathways.
independent
•
Reducing the irrigation/well
•" Reducing
irrigation/well pump
pump rate increased the DCGL for 1-129 most
significantly. Similarly,
significantly.
Similarly, increasing the pump rate decreased
decreased the DCGL for 1-129.
1-129. This
This
because reducing the pumping rate results in a lower dilution factor,
is because
factor, and
radionuclide inventory available for
increasing the pumping rate results in more radionuclide
exposure.
exposure.
•" The most significant effects of varying the Kd
Kd values were observed for U-234,
U-234 , which
Kd,d , to an increase
ranged from aa decrease
decrease of 71 percent
percent when lowering the K
increase of 867
867
Kd..
percent when increasing
increaSing the ~
Decreasing the hydraulic conductivity
1-129 due
•" Decreasing
conductivity significantly reduced the DCGL for 1-129
due
to reduced dilution
pathways at the
dilution and larger groundwater
groundwater dose
dose relative
relative to other pathways
the
time of peak dose.
increasing the hydraulic conductivity significantly
dose. Similarly, increasing
significantly
increased the DCGL for 11-129.
increased
-129.
runoff/evapotranspiration coefficients
•" Variations
Variations in the runoff/evapotranspiration
coefficients had the greatest effect
effect on U234 and 1-129,
1-129, and the least impact on U-232
U-232.. Radionuclides that are most sensitive
to this parameter have doses mainly due to water
water dependent
dependent pathways.
Decreasing the well
decreased the DCGL for 1-129,
1-129,
•* Decreasing
we ll intake depth most significantly decreased
while increasing th
this
parameter results in
in significantly increased
1-129,
increased the DCGL for 1-129,
is parameter
due to increased/decreased
increased/decreased dilution in
in the well water.
Changes to
contamination parallel
•" Changes
to the parameter
parameter for length of contamination
parallel to the aquifer flow
flow
DCGL, due to increased/decreased
increased/decreased
had the most significant
significant effect on the 1-129 DCGL,
dilution in the aquifer.
•
"• Changes
Changes to the hydraulic gradient most significantly
impacted 1-129,
1-129, due to the large
significantly impacted
large
water dependent
dependent pathway contributions.
contributions.
"
Decreasing the
the gamma shielding factor had no impact; however, increasing the
• Decreasing
the
shielding
shielding factor decreased the U-232
U-232 DCGL.
"• Changes
Changes to the indoor dust filtration factor had minimal impact
DCGLs, due to
impact on DCGLs,
relatively larger
pathways.
larger contribution
contribution to dose from other pathways.
"
Similarly, changes
changes to the dust loading
DCGLs, due to
• Similarly,
loading factor had minimal impact on DCGLs,
relatively larger
pathways.
larger contribution to dose from other pathways.
"
Decreases in root depth did not significantly
significantly impact
DCGLs; however,
however, increased
increased
impact the DCGLs;
• Decreases
root depths
depths impacted Sr-90 most significantly due to relatively large plant pathway
doses.
doses.
Revision 2
5-46
5-46
•
WVDP PHASE 1 DECOMMISSIONING
DECOMMISSION ING PLAN
•
•
Decreasing/increasing the plant transfer factors
increased/decreased
Decreasing/increasing
factors significantly
significantly increased/decreased
the DCGL for Sr-90,
Sr-90, as dose is mainly due to ingestion
ingestion via plant uptake from soil.
*• Use of the mass balance groundwater
groundwater model significantly
significantly decreases the DCGL for
for
Sr-90, Cs-137,
Cs-137, or U-232
U-232.. Radionuclides most sensitive
sensitive
U-234 but had no effect
effect on Sr-90,
to this parameter
dependent pathways.
parameter have doses mainly due to water
water dependent
pathways.
Table 5-10 summarizes
summarizes the sensitivity analyses performed for the subsurface soil initial
base-case
model
DCGLs, which are detailed in
in Appendix
C.
Appendix C.
base-case
DCGLs,
Table 5-10 Summary of Sensitivity Analyses - Subsurface
Subsurface Soil DCGLs
DCGLs
Parameter
•
Change In
in
Sensitivity
Parameter
Parameter
Indoor/Outdoor
Indoor/Outdoor
Fraction
1
2
2
-32%
-32%
Contamination
Contamination
Zone Thickness
3
4
4
Unsaturated Zone
Unsaturated
Thickness
Thickness
5
6
Minimum
DCGL Change
Change
Minimum DCGL
Change
Nuclide(s)
Nuclide{s)
-25%
0%
0%
Cs-137
-67%
-67%
233%
233%
-65%
-65%
U-238
-4%
-4%
-1%
-1%
6
-50%
-50%
150%
150%
0%
Irrigation/Pump
Rate
7
8
-57%
-57%
70%
-39%
-39%
0%
C-3 r9
Cs-137
Sr-90
Cs 137 Sr
90
U-232 U-235
U-235
1-129
1
-1 29
Cs-137
Soil/Water
SoillWater
Distribution
Distribution
(Kd)
Coefficients (Kd)
Coefficients
99
lower
-86%
10
10
higher
higher
-20%
-20%
Hydraulic
Conductivity
11
12
12
-55%
-55%
57%
57%
0%
0%
0%
Runoff/
Runoff/
Evaporation
Coefficient
Coefficient
13
13
-23%
-23%
14
14
Indoor Gamma
Shielding Factor
Indoor Dust
Filtration
Filtration Factor
Inhalation
Inhalation Dust
Loading
Root Depth
Food Transfer
Transfer
Factors
•
Run
Revision 2
8
21%
21 %
70%
0%
0%
Maximum DCGL
DCGL Change
Change
Maximum
Change
Change
Nuclide(s)
Nuclide{s)
0.3%
0.3%
35%
35%
U-238
U-238
170%
170%
98%
98%
Sr-90
U-232
U-232
1-129
1
-129
58%
U-238
U-238
2218%
2218%
U-234
1-129
1
-129
Cs-137
57%
57%
20%
U-232
U-232
U-234
U-234
U-238
1-129
20%
1-129
U-238
116%
116%
U-232
U-232
U-232
2168%
2168%
U-234
U-234
no change
0%
0%
no change
change
no
0%
0%
no change
no change
change
-44%
-44%
U-234
61%
61 %
U-238
U-238
15%
15%
-11
-11%%
U-232
11
7%
117%
U-234
U-234
15
15
16
16
-38%
-38%
87%
87%
0%
0%
-27%
-27%
U-238
19%
19%
Cs-1 37
Cs-137
1%
1%
U-232
U-232
U-238
U-238
17
-60%
-60%
0%
U-238
Cs-137 1-129
0%
0%
U-235
U-235
18
18
-25%
-25%
0%
Cs-137 1-129
USr-90 U-233 UU-238
234 U-238
0%
0%
U-235
U-235
19
19
-70%
-70%
0%
U-238
1%
1%
20
20
67%
67%
0%
0%
U-235
U-235
0%
0%
U-233
U-233
Cs-1
37 1-129 Sr9Cs-137 1-129 Sr90
90
21
21
-67%
-67%
-65%
-65%
Sr-90
1%
1%
U-233
U-233
22
233%
233%
lower
higher
0%
0%
-0.1%
-0.1%
-93%
U-238
U-238
Sr-90
181%
181%
522%
522%
0%
Sr-90
Sr-90
U-234
23
24
24
higher
-93%
5-47
Sr-90
0%
U-234
WVDP
WVDP PHASE 1 DECOMMISSIONING
DECOMMISSIONING PLAN
•
Discussion
Discussion of
of Subsurface
Subsurface Soil
Soil Results
Results
The
The sensitivity
sensitivity analysis
analysis results
results for
for the
the subsurface
subsurface soil source
source initial base-case
base-case model
evaluated considering
considering those
those radionuclides
radionuclides that
that are
are the primary
primary dose drivers,
drivers, i.e.,
i.e.,
were evaluated
those
those that are likely to contribute
contribute significantly
significantly to predicted
predicted dose
dose based
based on
on available
available
characterization data
data (see Table 5-1).
5-1). The radionuclides
radionuclides are
are Sr-90 (due to water
water
characterization
independent
independent plant
plant uptake),
uptake), 1-129
1-129 (due to water
water dependent
dependent pathways),
pathways), Cs-137 (external
radiation
radiation dose),
dose), and
and uranium
uranium radionuclides
radionuclides (water dependent
dependent pathways).
pathways).
The sensitivity
sensitivity analysis
analysis of the subsurface
subsurface soil model
model for these radionuclides
radionuclides indicates
indicates
the following:
following :
*•
A lower
lower indoor
indoor exposure
exposure fraction
fraction results in aa DCGL decrease
decrease for Cs-137
Cs-137 and
and no
no
in
a
significant
exposure
results
significant
a significant
significant change for U-238.
U-238 . A higher indoor exposure results
increased
increased DCGL for U-232.
U-232. However,
However, it is unlikely that the indoor fraction is
is too low
low
based
on the local climate.
climate. Doses for these isotopes
isotopes are
are mainly
mainly due
due to external
based on
exposure, which accounts
accounts for the relative
relative sensitivity to this
this parameter.
exposure,
*•
The source
source thickness
thickness parameter
parameter sensitivity was most
most significant for Sr-90,
Sr-90, U-234,
U-234,
and U-238.
increased/decreased dose
dose
U-238. The sensitivity
sensitivity to this parameter
parameter is due to increased/decreased
pathways (both water
from the water ingestion
ingestion and plant pathways
water dependent
dependent and
and
independent).
"
•
Decreasing or increasing
increasing the
the unsaturated
unsaturated zone
zone thickness
thickness resulted in significant
significant
U-238..
changes for U-234
U-234 and U-238
•
The 1-129
1-129 and U-238 DCGLs were
were sensitive
sensitive to changes
changes in the irrigation/well
irrigation/well pump
pumping
rate but the Cs-137 DCGL was not. This effect is because
because reducing the pumping
factor, and increasing
increasing the pumping rate results in
rate results in aa lower dilution factor,
dependent pathways.
more dilution for water
water dependent
pathways.
*•
U-232,, UUKd values were observed
The most significant effects of varying the Kd
observed for U-232
234,
U-238.
234, and U-238.
*•
The hydraulic conductivity
conductivity changes
changes had no impact on DCGLs because
because the mass
used..
balance groundwater model was used
*•
The U-232 and U-234 DCGLs are sensitive to changes
changes in the runoff/
Radionuclides that are most sensitive to this
evapotranspiration
evapotranspiration coefficient. Radionuclides
this
pathways.
parameter have doses mainly due to water dependent
dependent pathways.
•*
UChanges to the gamma shielding factor most significantly
significantly impacted Cs-137 and U232, based on a relatively large external exposure dose.
•*
DCGLs, due to
The indoor dust filtration factor variations had no impact on DCGLs,
pathways.
relatively large dose contributions from other pathways.
•"
Changes to the dust loading factor had a minimal impact on DCGLs, due to
to
relatively large dose contributions
contributions from other pathways.
•*
Varying the root zone depth impacted the Sr-90 DCGL most significantly.
Revision 2
5-48
I
•
•
WVDP PHASE 1 DECOMMISSIONING
DECOMMISSIONING PLAN
•
*•
The plant transfer
Sr-90,, as the dose is mainly due to
transfer factor is most sensitive for Sr-90
ingestion via plant uptake
uptake..
Table 5-11
5-11 Summary of Sediment DCGL
DCGL Sensitivity Analysis
Analysis
In
Change in
Sensitivity
Parameter
Change
Change
1
-50%
2%
2%
1-129
1
-129
97%
97%
U-232
U-232
22
100%
100%
-50%
U-232
-3%
-3%
1-129
1-129
3
-50%
-50%
0%
0%
U-235
29%
Sr-90
44
200%
-23%
-23%
U-233
0%
Cs-137
Soil/Water
Distribution
Distribution
Coefficients
(Kd))
Coefficients (Kd
5
lower
-76.5%
-76.5%
U-234
26%
26%
U-232
6
6
higher
higher
-64.5%
-64.5%
U-233
U-233
52%
52%
U-234
U-234
Runoff/Evaporation
Runoff/Evaporation
Coefficient
7
-23%
-23%
15%
0%
-3%
Cs-137
8
4%
4%
0%
U-232
U-232
Cs-1 37
Parameter
Outdoor Fraction
Fraction
Source Thickness
Mass Loading for
Inhalation
Root Depth
•
Food Transfer
Factors
Factors
Run
Minimum
DCGL Change
Minimum DCGL
Change
8
15%
-3%
9
9
-70%
-70%
0%
0%
10
67%
67%
11
11
Nuclide(s)
1-129
1-129
Maximum DCGL
Change
Maximum
DCGL Change
Change
Change
Nuclide(s)
Nuclide(s)
0%
Cs-1 37
Cs-137 1-129
1-129
Sr-90 U-232
1%
1%
U-233
U-233
-3%
-3%
U-234
0%
Cs-137 1-129 Sr90
90
-67%
-67%
0%
0%
no change
0%
no change
change
12
233%
233%
0%
U-232 U-235
50%
50%
Sr-90
13
lower
higher
1%
1%
-98%
-98%
U-232
852%
852%
Sr-90
Sr-90
Sr-90
-13%
-13%
U-232
U-232
14
14
higher
Streambed Sediment Results
Discussion of Streambed
Results
The streambed sediment model sensitivity simulations
simulations have been evaluated
considering
considering those radionuclides
radionuclides that are likely to significantly contribute
contribute to the overall
overall doses
in this media, which are Sr-90 (venison ingestion) and
and Cs-137 (external radiation dose).
dose).
The sensitivity
model,, for these radionuclides,
sensitivity analysis for the sediment
sediment model
radionuclides, indicates:
•
•"
The DCGLs for Sr-90 and Cs-137 are inversely
inversely related to changes
changes in outdoor
fraction, with Cs-137 being the most sensitive.
sensitive. Radionuclides
Radionuclides with primary doses
from external
parameter.
external exposure
exposure pathways are more sensitive to changes in this parameter.
•"
Decreasing the source thickness
Cs-137.
Decreasing
thickness results in higher DCGLs for Sr-90 and Cs-137.
While increasing the source
radionuclides,, Sr-90
source thickness
thickness has little effect
effect on these radionuclides
is most sensitive to this parameter.
•*
Varying the Kd
Kd values had a minimal effect on the Cs-137 DCGL,
DCGL, but decreasing
decreasing
the Kd decreased
decreased the Sr-90 DCGL due to doses from water dependent pathways.
Revision 2
Revision
5-49
DECOMMISSIONING PLAN
WVDP PHASE 1 DECOMMISSIONING
"
•
Varying
Varying the runoff/evapotranspiration
runoff/evapotranspiration coefficient had little effect on Cs-137 or Sr-90
to
DCGLs. Radionuclides
Radionuclides most sensitive to this parameter have doses mainly due to
water dependent pathways.
pathways.
"
•
loading factor had minimal impact on DCGLs
DCGLs..
Changes to the mass loading
*•
however, increasing
the
depth did not impact DCGLs;
DCGLs; however,
increasing the
Decreasing the root zone depth
depth increased
increased the Sr-90 DCGL significantly.
significantly.
*•
Decreasing both plant and fish transfer factors resulted in increased DCGLs for Srin decreased DCGLs for both Cs-137
90, and increasing these parameters
parameters resulted in
Cs-137
and Sr-90.
•
Changes to Base-Case
Base-Case Models Based on Sensitivity Analysis Results
Results
Changes
Development
process
Development of the conceptual
conceptual model for surface
surface soil DCGLs
DCGLs was an iterative process
assumptions for model parameters and took into account
that used conservative
conservative assumptions
account the results
of early model runs and the related input parameter
parameter sensitivity analyses.
analyses.
The initial model runs produced inordinately low DCGLs for uranium radionuclides
in
radionuclides in
calculated DCGLw
example, was 1.0 pCi/g,
surface soil. The calculated
DCGL w for U-238,
U-238 , for example,
pCi/g , slightly above
surface soil shown in Table 4-11 of this plan.
plan .
measured background concentrations
concentrations in surface
measured
The next iteration involved changes to radionuclide
radionuclide distribution coefficients.
coefficients. Evaluation
Evaluation
of the basis for the original distribution
distribution coefficients and sensitivity analysis results led to the
the
conclusion that some distribution coefficients
coefficients used
used were inappropriate.
inappropriate. These distribution
distribution
coefficients were changed. The resulting distribution
distribution coefficients
coefficients are based either on sitespecific data for the sand and gravel layer or, where site-specific
site-specific data are not available,
values for sand from Sheppard and Thibault
Thibault 1990,
C-2.
1990, as shown in Table C-2.
radionuclides, e.g.,
These model changes produced
produced higher DCGLw
DCGLw values for uranium radionuclides,
e.g .,
U-238. However,
However, these values were still low compared
4.8 pCi/g for U-238.
compared to uranium
uranium DCGLs for
unrestricted
main
unrestricted release developed
developed at other sites.
sites. Further evaluation
evaluation showed
showed that the main
reason for the low uranium DCGLs was the conservative use of the RESRAD mass
mass
balance model.
considering the results of the sensitivity analysis that evaluated
evaluated use of
model. After considering
14
14
the non-dispersion model
model,, and RESRAD
guidance ,, it was determined to be more
more
RESRAD Manual guidance
appropriate to use the non-dispersion
done.
appropriate
non-dispersion model in the surface
surface soil analysis and this
th is was done.
•
The probabilistic
probabilistic uncertainty
uncertainty analysis discussed in the next subsection
SUbsection provided
provided insight
conservatism in model
producing DCGLs that were
model input parameters,
parameters, producing
were
into the degree of conservatism
analyses.
generally lower than those from the deterministic
deterministic analyses.
5.2.7
Probabilistic Uncertainty Analysis
Analysis
The probabilistic uncertainty
uncertainty analysis has been performed
performed for each of the three
three
conceptual
models
to
supplement
the
deterministic
sensitivity
analyses
just
described.
conceptual
deterministic
described .
These probabilistic
the
probabilistic analyses generated
generated results that quantify
quantify the total uncertainty
uncertainty in the
14 The RESRAD Manual (Yu, et al. 2001) notes Appendix E that:"The user has the option of selecting
14 The RESRAD Manual (Yu , et al. 2001) notes in
in Appendix E that "The user has the option of selecting
which
[groundwater] model to use.
the MB
MB [mass
[mass balance]
is used for smaller
smaller contaminated
contaminated
which [groundwater]
use. Usually,
Usually, the
balance] model is
areas (e.g., 1,000 m22 or less) and the ND [non-dispersion] model is used for larger areas."
areas (e.g ., 1,000 m or less) and the ND [non-dispersion] model is used for larger areas ."
Revision 2
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•
DECOMMISSIONING PLAN
WVDP PHASE 1 DECOMMISSIONING
•
parameters, and also provide perspective
DCGLs resulting from the variability of key input parameters,
perspective
regarding the relative
relative importance of the contributions of different
different input parameters to the
the
approach to
DCGLs. This information supports a risk-informed approach
uncertainty in the DCGLs.
total uncertainty
establishing cleanup goals for Phase 1 of the decommissioning.
decommissioning .
These analyses were performed
performed using the probabilistic modules of RESRAD
RESRAD version
6.4 , which utilize Latin hypercube
hypercube sampling,
sampling , a modified
modified Monte Carlo method,
method , allowing for
6.4,
representative input parameter values from all segments
segments of the input
generation of representative
the generation
distributions. Input variables
variables for the models were selected
selected randomly from probability
distributions.
parameters treated
distribution functions for each parameter of interest. The number of parameters
distribution
102, subsurface
follows:: surface soil 102,
subsurface soil
probabilistically for each conceptual
conceptual model was as follows
67 , and streambed
streambed sediment 63, with these figures including the biotransfer
biotransfer factors and the
the
67,
(contaminated,, saturated
saturated,,
Kd values for the 18
18 radionuclides of interest for each zone (contaminated
unsaturated) and media each
each model. Appendix
Appendix E provides details of the analyses.
analyses .
Table 5-1
5-11laa summarizes
summarizes the results of the analyses.
analyses.
Probabilistic Uncertainty
Table 5-11a.
S-11a. Summary of Results of Probabilistic
Uncertainty Analysesý')
Analyses(1)
Surface Soil DCGLs Subsurface
Subsurface Soil DCGLs
(pCi/g)
(pCl'g)
(pCi/g)
Nuclide
Nuclide
Limiting
Peak-ofDeterm(2) Peak-ofLimitin~
Determ(2)
3
3
the-Mean(3)
the-Mean(3)
)
Determ
)
the.Mean(
)
Determnn)
the-Mean(
•
•
DCGLs
Streambed Sediment
Sediment DCGLs
(pCl'g)
(pCi/g)
Determ(5 )
Peak-of-the.Mean(3)
Determ(5)
Peak-of-the-Mean(3)
Am-241
Am-241
4.3E+01
4.3E+01
2.9E+01
7.1EE+03
7.1 E+03
6.8E+03
1.6E+04
1.6E+04
1.OE+04
1.0E+04
C-14
2.0E+01
1.6E+01
1.6E+01
3.7E+05
3.7E+OS
7.2E+05
3.4E+03
3.4E+03
1.8E+03
1.8E+03
Cm-243
4.1E+01
4.1E+01
3.5E+01
3.SE+01
1.2E+03
1.IE+03
1.1E+03
3.6E+03
3.6E+03
3.1E+03
3.1E+03
Cm-244
8.2E+01
6.5E+01
6.SE+01
2.3E+04
2.2E+04
4.8E+04
3.8E+03
Cs-137(6) 2.4E+01
1.5E+01
1.SE+01
4.4E+02
3.OE+02
3.0E+02
1.3E+03
1.3E+03
1.0E+03
1.0E+03
1-129
3.5E-01
3.3E-01
5.2E+01
S.2E+01
6.7E+02
3.7E+03
3.7E+03
7.9E+02
Np-237
9.4E-02
2.6E-01
4.3E+00
4.3E+OO
9.3E+01
5.2E+02
5.2E+02
3.3E+02
3.3E+02
Pu-238
5.OE+01
5.0E+01
4.0E+01
1.5E+04
1.5E+04
1.4E+04
1.4E+04
2.OE+04
2.0E+04
1.2E+04
1.2E+04
Pu-239
4.5E+01
2.5E+01
2.SE+01
1.3E+04
1.3E+04
1.2E+04
1.2E+04
1.8E+04
1.2E+04
1.2E+04
Pu-240
4.5E+01
2.6E+01
1.3E+04
1.3E+04
1.2E+04
1.2E+04
1.8E+04
1.8E+04
1.2E+04
1.2E+04
Pu-241
1.4E+03
1.2E+03
1.2E+03
2.4E+05
2.4E+OS
2.5E+05
2.5E+05
5.1E+05
5.1E+05
3.4E+05
3.4E+OS
Sr-90(6)
Sr-90(6)
6.3E+00
6.3E+OO
4.1 E÷00
4.1E+OO
3.2E+03
3.4E+03
9.5E+03
9.5E+03
4.7E+03
Tc-99
2.4E+01
2.1E+01
1.1E+04
1.1E+04
1.4E+04
2.2E+06
2.2E+06
6.6E+05
6.6E+OS
U-232
U-232
5.8E+00
5.8E+OO
1.5E+00
1.SE+OO
1.OE+02
1.0E+02
7.4E+01
7.4E+01
2.6E+02
2.2E+02
2.2E+02
U-233
1.9E+01
8.3E+00
8.3E+OO
1.9E+02
9.9E+03
9.9E+03
5.7E+04
2.2E+04
2.2E+04
U-234
2.0E+01
8.5E+00
8.SE+OO
2.0E+02
2.0E+02
1.3E+04
6.OE+04
6.0E+04
2.2E+04
2.2E+04
Revision 2
5-51
-------------------------~-. ~----
.. - -
-_ .. -
- ---
WVDP
WVDP PHASE
PHASE 1 DECOMMISSIONING
DECOMMISSIONING PLAN
5-11a. Summary
Summary of
of Results
Results of
of Probabilistic
Probabilistic Uncertainty
Uncertainty Analyses°•
Analyses(l )
Table 5-11a.
Surface
Surface Soil
Soil DCGLs
DCGLs Subsurface
Subsurface Soil
Soil DCGLs
(pCi/g)
(pCi/g)
Nuclide
Nuclide
(pCi/g)
(pCi/g)
Streambed
Streambed Sediment
Sediment DCGLs
DCGLs
(pCi/g)
(pCilg)
Peak-of-
Limitin~
Limiting
Determ )
Determ
Peak-of-3 )
Peak-ofthe-Mean(3)
the-Mean
5
Determ(
Determ(5))
Peak-of-the-Mean(3)
Peak-of-the-Mean(3)
2
Determ(2)
) Peak-ofDeterm(
t3
the-Mean(3)
the-Mean
)
U-235
U-235
1.9E+01
1.9E+01
3.5E+OO
3.5E+00
2.1E+02
2.1E+02
9.3E+02
9.3E+02
2.9E+03
2.9E+03
2.3E+03
2.3E+03
U-238
U-238
2.1E+01
2.1E+01
9.8E+OO
9.8E+00
2.1E+02
2.1E+02
4.6E+03
4.6E+03
1.2E+04
1.2E+04
8.2E+03
8.2E+03
•
NOTES : (1) Values
Values shown
shown in boldface
boldface are
are lower of
of the
the pair of
of values
va lues being
being compared.
compa red .
NOTES:
Revised deterministic
deterministic DCGLs
DCGLs based
based on
on parameter
parameter changes
changes described
described in
in Appendix
Appendix C.
C.
(2) Revised
(3) Probabilistic
Probabilistic peak-of-the-mean
peak-of-the-mean DCGLs
DCGLs based
based on analyses
analyses described
described in Appendix
Append ix E.
E.
(4) These
va lues are
are the
the limiting
limiting DCGLs
DCGLs for
fo r subsurface soil
soil from the residential
residentia l gardener
gardener alternate
alternate scenario
scenario
These values
5.2.8, which describes
in Section
Section 5.2.8,
describes
discussed above.
above. Subsurface
soil DCGLs
DCGLs are
are discussed
discussed further
further in
Subsurface soil
analysis discussed
the results
an analysis that
that takes into
in to account continuing
co ntinuing releases
releases from
from the bottoms
bottoms of the
the remediated
results of an
deep
deep excavations.
excavations.
parameter
(5)
(5) These
These are the revised DCGLs based
based on para
meter changes
changes described
described in Appendix
Appendix C.
C.
(6) These values
values take into account 30 years decay.
decay.
Table 5-1
5-11Iaa shows that:
"
•
For surface
surface soil,
soil , the peak-of-the-mean
peak-of-the-mean probabilistic
probabilistic DCGLs are
are lower
lower than the
the
radionuclides except Np-237.
revised deterministic DCGLs
DCGLs for all radionuclides
Np-237.
*•
soil, the limiting deterministic
deterministic analysis
analysis results
results from the residential
For subsurface
subsurface soil,
gardener alternative
alternative scenario described
described above are
are more limiting than the peak-ofgardener
the-mean
radionuclides . (However,
(However, the additional
the-mean DCGLs for 10 of the 18 radionuclides.
deterministic
deterministic multi-source
multi-source analysis
analysis that includes continuing
continuing releases
releases from the
the
bottoms of the remediated
excavations as discussed
discussed in
in Section
Section 5.2.8
5.2.8 results
results
remediated deep excavations
bottoms
radionuclides of interest.)
interest.)
in even lower DCGLs for many of the radionuclides
•*
peak-of-the-mean DCGLs
streambed sediment,
sediment, the peak-of-the-mean
For streambed
DCGLs are more limiting than the
the
revised deterministic DCGLs.
DCGLs.
•
th
95t"
For most
rad ionuclides, the 95
percentile probabilistic DCGLs are lower than the
the
most radionuclides,
peak-of-the-mean DCGLs are
peak-of-the-mean DCGLs as shown in Appendix E.
peak-of-the-mean
E. The peak-of-the-mean
NRC
considered
considered to be appropriate to compare
compare with the deterministic DCGLs because
because NRC
dose
peak-of-the-mean dose
modeling,, the peak-of-the-mean
indicates that when using probabilistic dose
dose modeling
Rule
compliance with its License
distribution
distribution should be used for demonstrating
demonstrating compliance
License Termination Rule
10 CFR 20,
in 10
20, Subpart
Subpart E (NRC 2006).
2006).
After consideration of the results of the probabilistic
probabilistic uncertainty analysis
analysis and the
analyses
analyses of alternate
alternate exposures
exposures discussed previously,
previously, DOE has determined
determined that it is
peak-of-the-mean DCGLs for surface soil
appropriate
appropriate to use the peak-of-the-mean
soil and for streambed
evaluations.. Subsurface soil
sediment
sediment and the lowest DCGLs of the various
various subsurface soil evaluations
DCGLs are addressed
addressed in Section 5.2.8.
5.2.8
5.2.8
Multi-Source Analysis
Analysis
Subsurface Soil DCGL Multi-Source
developing
5.2.1, the original base-case conceptual model used in developing
As noted in Section 5.2.1,
the subsurface soil DCGLs recognizes one source of contamination
contamination - the Lavery till from
Revision
Revision 2
5-52
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•
WVDP PHASE 1 DECOMMISSIONING
DECOMMISSIONING PLAN
•
deep excavations
surface during construction
construction
excavations that is brought to the surface
the bottom of one of the deep
groundwater
potential impacts to groundwater
hypothetical cistern.
cistern . This model does not consider potential
of the hypothetical
backfilled excavation from continuing
in the backfilled
continuing release of remaining residual radioactivity
radioactivity at
the bottom of the deep excavations.
excavations.
limitation , analyses were performed
performed that take into account
account the impacts
impacts
To address this limitation,
hypothetical residential gardener
gardener
of releases of this other residual radioactivity on both a hypothetical
subsurface
and a resident
resident farmer with a modified model that accounts for a surface
surface and a subsurface
Figure 5-13 illustrates the modified
modified conceptual
conceptual model used in these
radiation.. Figure
source of radiation
analyses.
analyses.
r
zone
Four surface contamination
contamination zone
geometry/dilution factor (DF) combinations
geometry/dilution
combinations
3
M3 plug of
evaluated based on removal of a 3 m
unweathered Lavery till to the surface:
unweathered
surface:
2
(1) 2000 M
thick , with a soil DF of 100
100
m2 ,, 0.15 m thick,
2
(2) 2000 M
thick, with aa soil DF of 1
m , 0.0015 m thick,
2
(3)
thick, with a soil DF of 667
(3) 2000 M
m2 ,, 1 m thick,
667
2
(4) 10,000
M ,, 1 m thick,
10,000 m
thick, with aa soil DF of 3333
Ia
A residential gardener
average
gardener is the average
member of the critical group for the
the
22
2000
M area scenarios.
scenarios. A resident
2000 m
the
farmer is the average member2of the
m2
the 10,000
critical group
10,000 m
group for
for the
scenario.
scenario.
-
lffýr
-I
-
I
-911
Backfill,
unsaturated zone (2 m thick)
Backfill , unsaturated
in area where cistern
Contamination
Contamination on bottom of excavation in
is installed is brought to surface
surface and remaining subsurface
contamination
contributes to
to groundwater
source
source contributes
groundwater contamination
•
j
Backfill, saturated
Backfill,
saturated zone
zone
Well (cistern) intake depth
depth 5 m below water table]
table
2
M2 ,, 1 m thick,
thick,
I Assumed 10,000 m
Contamination
diffuses into backfill
early on
located 10 m below surface
Residual Radioactivity at Bottom of Excavation (Unweathered Lavery Till)
Diffusion/dispersion spreads
Diffusion/dispersion spreads
contamination
oetieShale
contamination downward
downward over
time
Hyw thetical cistern
deep)
10 mn
ca
Bedrock.
Figure 5-13.
5-13. Modified Conceptual Model for Subsurface
Figure
Subsurface Soil DCGL Development
Development
With this model
model,, the subsurface soil DCGLs are based on exposure to residual
radioactivity associated with the bottom of the deep
unweathered Lavery
deep excavation
excavation in the unweathered
installation
till,
surface during
during insta
llation of
till , with (1) soil from this area assumed
assumed to be relocated to the surface
excavation bottom
a cistern and (2) with the remaining contaminated
contaminated Lavery till in the excavation
•
Revision 2
5-53
5-53
WVDP PHASE 1 DECOMMISSIONING
DECOMMISSIONING PLAN
serving as a continuing source
source of contaminants
contaminants to groundwater.
groundwater. These sources and the
the
exposure pathways
exposure
pathways considered
considered are described below.
Excavation Bottom
Contamination
Excavation
Bottom Treated
Treated as Two Sources
Sources of Contamination
The excavation bottom is treated as two distinct sources:
sources: (1) a plug of contaminated
excavation bottom that is brought to the surface during installation of the
the
soil from the excavation
garden , and (2) the remaining
remaining
cistern and spread over the entire surface of the hypothetical
hypothetical garden,
contaminated Lavery till at the excavation
radioactivity moves
contaminated
excavation bottom from which residual radioactivity
moves
drawn into the well. Both the residential
upward by diffusion and enters groundwater
groundwater being drawn
gardener scenario
scenario and the resident farmer scenario were considered as indicated in Figure
5-13.
5-13.
•
The surface
surface source
source that results from the contribution
contribution of contamination
contamination in soil being
removed from the bottom of the excavation
excavation and brought to the surface and the contribution
of contamination in irrigation
irrigation water has the following characteristics:
characteristics:
*•
It is assumed that the contaminated
contaminated material
It
material is evenly spread across the entire
hypothetical garden and mixed uniformly in the soil to varying depths
depths (the surface
hypothetical
contamination zone),
*•
Exposure occurs from direct exposure and soil pathways
pathways associated
associated with
surface, and
contaminated soil brought to the ground surface,
*•
Exposure occurs from groundwater
groundwater pathways
pathways as contaminated
contaminated water is drawn into
the well and used as irrigation water resulting in plant contamination
contamination and animal
contamination where
these
plants
are
used
as
feed.
As
feed
.
a result, the resident is
where
used
radioactivity from the plants being
exposed to radioactivity
being consumed
consumed and, in the case of the
the
resident farmer scenario,
scenario, from meat and milk produced from cattle that have been
raised on the contaminated feedstock.
feedstock.
The subsurface
subsurface source remaining at the bottom of the excavation is assumed
assumed to have
have
characteristics:
the following characteristics:
"
•
The diffusive
contamination from the excavation
excavation bottom (the
(the
diffusive movement of contamination
subsurface
immediately after
subsurface contamination zone) begins immediately
after the excavation is
contaminating the aquifer,
backfilled and results in contaminating
"
•
Contaminated groundwater
groundwater entering the well is a source to soil in the surface
surface
garden,, and
contamination zone because well water is used to irrigate the garden
•
Drinking water exposure occurs from contaminated
contaminated well water being used as aa
source
of
drinking
water.
source drinking
•
5-1 lbb shows the exposure pathways
Table 5-11
pathways evaluated.
evaluated .
Table 5-11
b. Exposure Pathways for Modified Subsurface Soil DCGL Model
5-11b.
Exposure Pathways
Residential
Resident
Residential
Resident
Exposure Pathways
Farmer
Gardener
Farmer
Gardener
External gamma radiation
radiation from contaminated soil
Inhalation of airborne radioactivity
radioactivity from re-suspended
Inhalation
re-suspended
Revision 2
5-54
Yes
Yes
Yes
Yes
Yes
Yes
•
WVDP PHASE 1 DECOMMISSIONING
DECOMMISSIONING PLAN
•
Table 5-11b. Exposure
Exposure Pathways for Modified Subsurface
Subsurface Soil DCGL Model
Residential
Gardener
Resident
Resident
Farmer
Plant ingestion (produce impacted
impacted by contaminated soil
and groundwater
groundwater contaminated
contaminated by primary and secondary
sources)
Yes
Yes
Yes
Meat ingestion (beef impacted
impacted by contaminated soil and
groundwater contaminated
contaminated by primary
primary and secondary
sources)
No
Yes
Yes
Milk ingestion (impacted
(impacted by contaminated
contaminated soil and
groundwater contaminated
groundwater
contaminated by primary and secondary
sources)
No
Yes
Yes
Aquatic food ingestion
Ingestion of drinking water (from groundwater
groundwater
contaminated by primary and secondary
secondary sources)
No
No
Yes
Yes
Yes
Soil ingestion
Yes
Yes
Yes
Radon inhalation
inhalation
No
No
Exposure Pathways
Exposure Pathways
contaminated
contaminated soil
Details of the modeling including values of input parameters
parameters such as distribution
coefficients appear
appear in the calculation
calculation package (Price 2009).
coefficients
Mathematical
Mathematical Models
Models
Calculation
three-dimensional near
combined dose utilized
utilized information from the three-dimensional
Calculation of the combined
groundwater transport,
transport, a model
field STOMP finite difference
difference model of the north
north plateau for groundwater
contamination from the subsurface
subsurface
that estimated
estimated the drinking water dose associated with contamination
source diffusing into the aquifer,
aquifer, and RESRAD dose to source ratios associated
associated with unit
concentrations to determine
pathways. The calculations were
soil concentrations
determine the total dose from all pathways.
were
implemented with a FORTRAN
dependent
implemented
FORTRAN language computer program that estimates
estimates time dependent
impacts.1.155
human health impacts
•
concentrations over
time
The model performs mass balance
balance calculations
calcu lations and develops concentrations
over time
for three distinct
distinct areas (1) the remaining subsurface source,
source , (2) the backfilled saturated
zone, and (3) the surface which has been contaminated
the
contaminated with material excavated from the
subsurface
source
and
radionuclides
in
irrigation
water.
subsurface
radionuclides
In order to identify controlling scenarios, the area of the contaminated
contaminated zone
In
zone at the
the
surface and the degree
garden were varied.
varied.
degree of mixing into the soil of the garden
The STOMP model
model was executed
executed with parameter
parameter values for the contaminated area and
corresponded with assumptions used in the RESRAD
well pumping rates that corresponded
RESRAD model for the
exposure scenarios under consideration
consideration.. A contaminated
area
of
10,000
m2 and pumping
pumping
contaminated
rate of 5720 m3/y were used to evaluate the resident farmer, and a contaminated
contaminated area of
2
3
2,000 m
m2 and well pumping rate of 1140 m 3/y were used to evaluate the residential
gardener scenario.
scenario. The residential
residential gardener scenario
scenario assumed
assumed several source
source
15These analyses were deterministic analyses. Consideration was given to performing probabilistic analyses
These analyses were deterministic analyses . Consideration was given to performing probabil istic ana lyses
instead.
complexity of
probabilistic analysis
instead . However,
However, the
the complexity
of the
the multi-source
multi-source model
model made
made aa probabilistic
analysis impractical.
impractical.
15
•
Revision 2
Revision
5-55
5-55
WVDP PHASE 1 DECOMMISSION
DECOMMISSIONING
ING PLAN
configurations within the contaminated
contaminated area for the three m3 of contaminated
contaminated Lavery till
configurations
excavated to the surface:
assumed to be excavated
"
•
Contamination is spread over the surface
undiluted
(1 .5 mm thick) of undiluted
Contamination
surface in a thin layer
layer (1.5
till,
till ,
*•
Contamination is spread over
Contamination
over the surface
surface and then tilled into the soil to a depth of
15 cm, and
*•
Contamination is spread
Contamination
spread over the surface
surface and then tilled into the soil to a depth of 1
m.
m.
•
determined to be most limiting for each radionuclide
The source configuration
configuration determined
radionuclide was used as
as
the basis for the development of the subsurface
DCGLs.
subsurface DCGLs.
Results
Results
Table 5-11 c shows the results of the analyses
analyses compared
compared to DGCLs developed
developed using
models..
other conceptual
conceptual models
Compar ison (pCi/g)(1)
Table 5-11c. Subsurface
Subsurface Soil DCGL Comparison
(pCl/g)(11
Nuclide
Nuclide
Driller
Recreat.
Recreat.
Hiker
Hiker
Lagoon 33 Natural
Lagoon
Natural Gas
Gas
Erosion
Well Driller
Erosion
Well Driller
Multi-Source Cistern Well
Multi-Source
Driller
Basic
Basic
Deterministic
Deterministic
Delst
Models(2)
Models(2)
Probabilistic
Probabilistic
Peak of thePeak
of theMean
Mean
Mean
Am-241
6.3E+03
1.7E+04
1.7E+04
2.7E+05
2.7E+OS
2.9E+05
2.9E+OS
1.4E+05
1.4E+OS
7.1E+03
6.8E+03
C-14
9.9E+02
2.3E+09
3.3E+08
6.4E+06
6.4E+06
4.9E+09
3.7E+05
3.7E+OS
7.2E+05
7.2E+OS
Cm-243
3.6E+03
1.1E+04
1.1
E+04
5.OE+04
S.OE+04
1.8E+05
1.8E+OS
1.2E+05
1.2E+OS
1.2E+03
1.1E+03
1.1E+03
Cm-244
3.4E+04
3.3E+04
3.3E+04
1.0E+09
3.9E+05
3.9E+OS
2.6E+05
2.6E+OS
2.3E+04
2.2E+04
2.2E+04
Cs-137(3)
Cs-1 37(3)
2.8E+03
6.7E+03
6.7E+03
9.8E+05
9.8E+OS
7.4E+05
7.4E+OS
9.2E+04
4.4E+02
3.OE+02
3.0E+02
1-129
7.5E+00
7.SE+OO
8.OE+05
8.0E+OS
1.9E+06
3.5E+05
3.SE+OS
9.2E+06
5.2E+01
S.2E+01
6.7E+02
Np-237
1.OE+00
1.0E+OO
6.6E+03
6.6E+03
2.7E+04
5.9E+05
S.9E+OS
6.6E+04
4.3E+00
4.3E+OO
9.3E+01
Pu-238
1.3E+04
1.3E+04
2.OE+04
2.0E+04
1.5E+06
1.SE+06
2.7E+05
2.7E+OS
1.6E+05
1.6E+OS
1.5E+04
1.SE+04
1.4E+04
1.4E+04
Pu-239
3.1E+03
1.9E+04
2.8E+05
2.8E+OS
2.4E+05
2.4E+OS
1.5E+05
1.SE+OS
1.3E+04
1.2E+04
1.2E+04
Pu-240
Pu-240
3.4E+03
1.9E+04
2.8E+05
2.8E+OS
2.4E+05
2.4E+OS
1.5E+05
1.SE+OS
1.3E+04
1.3E+04
1.2E+04
1.2E+04
Pu-241
5.5E+05
S.SE+OS
5.5E+05
S.SE+OS
1.7E+07
1.2E+07
4.5E+06
4.SE+06
2.4E+05
2.4E+OS
2.5E+05
2.SE+OS
Sr-90(3)3
Sr-90( )
2.8E+02
8.7E+05
8.7E+OS
1.6E+08
9.2E+06
1.1E+07
1.1
E+07
3.2E+03
3.4E+03
Tc-99
5.9E+02
S.9E+02
7.9E+07
2.2E+08
2.2E+08
4.7E+07
9.4E+08
1.1E+04
1.4E+04
1.4E+04
U-232
8.8E+01
1.6E+03
2.8E+04
4.5E+05
4.SE+OS
1.6E+04
1.0E+02
7.4E+01
U-233
2.7E+02
6.2E+04
1.3E+06
2.9E+06
4.9E+05
4.9E+OS
1.9E+02
1.9E+02
9.9E+03
U-234
2.8E+02
6.4E+04
1.4E+06
3.1E+06
3.1E+06
5.OE+05
S
.OE+OS
2.OE+02
2.0E+02
1.3E+04
1.3E+04
U-235
U-23S
2.9E+02
1.2E+04
4.2E+04
3.2E+06
1.4E+05
1.4E+OS
2.1E+02
9.3E+02
U-238
3.OE+02
3.0E+02
3.7E+04
1.9E+05
1.9E+OS
3.3E+06
3.6E+05
3.6E+OS
2.1E+02
4.6E+03
•
NOTES:
NOTES: (1) The lowest DCGLs are shown in boldface.
boldface.
deterministic resident farmer and residential gardener
gardener DCGLs.
DCGLs.
(2) The lower value of the deterministic
(3) These values take into account 30 years decay.
Revision 2
5-56
5-56
•
WVDP
WVDP PHASE
PHASE 1 DECOMMISSIONING
DECOMMISSIONING PLAN
PLAN
•
In
In nine
nine cases,
cases , the
the DCGLs
DCGLs developed
developed using
using other
other conceptual
conceptual models are
are lower
lower than the
the
DCGLs
DCGLs developed
developed by
by the multi-source
multi-source model that accounts
accounts for continuing
continuing releases
releases from
from the
the
the deep
deep excavations:
excavations:
bottom of the
*•
The
probabilistic DCGLs,
DCGLs, which
which did
did not take
take into
into account
account
The peak-of-the-mean
peak-of-the-mean probabilistic
are
lower
for
Cmexcavations,
excavations,
are
lower
Cmcontinuing
releases
from
the
bottom
bottom
of
the
deep
continuing releases
243, Cm-244,
Cm-244, Cs-137,
Cs-137, and
and U-232;
U-232 ; and
and
243,
*•
The
The limiting
limiting deterministic
deterministic DCGL from the deterministic
deterministic resident farmer and
and
residential gardener
gardener conceptual
conceptual models,
models, which
which did
did not take
take into account
account continuing
continuing
U-234,
releases
releases from the bottom of the excavations,
excavations, was lower for Pu-241,
Pu-241 , U-233,
U-233 , U-234,
U-235, and
and U-238.
U-238.
U-235,
This situation can be
be attributed
attributed to conceptual
conceptual model
model differences
differences such as
as different
different
contamination
contamination zone geometry.
geometry.
Conclusions
5.2.9
5.2.9 Overall
Overall Conclusions
iterative process.
Development of DCGLs proved
Development
proved to be an iterative
process.
be
DCGLs, the initial-base
For surface
surface soil
soil DCGLs,
initial-base case conceptual
conceptual model was determined
determined to be
conservative than
more conservative
than an alternate
alternate conceptual
conceptual model involving erosion
erosion and the resulting
probabilistic peak-of-the-mean
DCGLs
potential doses
doses to an offsite
offsite receptor.
receptor. However,
However, the probabilistic
peak-of-the-mean DCGLs
base-case deterministic
deterministic DCGLs
were
were lower than the base-case
DCGLs for all
all radionuclides
radionuclides except Np-237.
Np-237.
The
peak-of-the-mean DCGLs
The peak-of-the-mean
DCGLs were therefore
therefore selected as the basis for the surface soil
cleanup
cleanup goals to be conservative.
conservative .
•
For subsurface
subsurface soil DCGLs,
DCGLs, analysis
analysis of the residential
residentia l gardener and the multisource
multisource
alternate conceptual
conceptual models
models showed that the initial base-case
base-case resident
resident farmer model was
was
into
provided additional insight into
not conservative.
conservative. The
The probabilistic
probabilistic uncertainty
uncertainty analysis provided
deep
excavations.
In
at
the
bottom
of
the
doses
from
residual
radioactivity
potential future
excavations. In
future
bottom
the interest of conservatism,
conservatism, the lowest DCGLs
DCGLs produced by the various models were
were
selected as the basis for the subsurface
subsurface soil cleanup
cleanup goals.
the
base-case model produced essentially
For streambed sediment DCGLs, the refined base-case
essentially the
peak-of-the-mean
base-case model. However, the probabilistic peak-of-the-mean
same DCGLs as the initial base-case
DCGLs were lower and were therefore
therefore selected as the basis for the cleanup goals.
5.3
Assessment
Limited Site-Wide Dose Assessment
Limited
This section describes the limited integrated dose assessment
assessment performed
performed to ensure
activities will not limit options for Phase 2 of the
in Phase 1 remediation
that criteria used in
remediation activities
decommissioning..
decommissioning
5.3.1
Assessment
Basis for this Assessment
the
appropriate,, considering the
Section 5.1.3 explains why such a dose assessment
assessment is appropriate
the
5-4. Section 5.1.3 also explains that the
Figure 5-4.
Phase 1 and Phase 2 sources illustrated in Figure
appropriate dose assessment involves a hypothetical individual engaged in farming at
appropriate
remediated project premises who also spends
some time in the future on one part of the remediated
spends
time fishing and hiking at Erdman Brook and Franks Creek.
•
Revision 2
5-57
5-57
I
WVDP PHASE 11 DECOMMISSIONING
WVDP
DECOMMISSIONING PLAN
This scenario would involve an individual being exposed to two different remediated
different critical groups.
groups. As described
source areas and being a member of the two different
described in
Section 5.2,
exposure group for the resident
resident farmer scenario
scenario used for development of
5.2, the exposure
DCGLs for surface and subsurface
exposure group for
subsurface soil is significantly different
different from the exposure
the development
development of the streambed
streambed sediment
sediment DCGLs, which involves a hypothetical
individual spending
hunting
individual
spending a relatively small fraction of his or her time hiking,
hiking, fishing,
fishing , and hunting
in the areas of Erdman Brook and Franks Creek.
Creek.
•
In both of these cases,
hypothetical individual (the average
average
cases, it was assumed that the hypothetical
member of the critical group) would be exposed only to the residual radioactivity of interest.
That is, the resident farmer would not be exposed to residual radioactivity in the areas of
the streams
streams and the recreationist would not be exposed
exposed to residual radioactivity in surface
surface
soil or subsurface
subsurface soil.
5.3.2
Assessment Approach
Approach
Assessment
The approach
approach used involves
involves partitioning doses between
between two critical groups and two
(1) the resident
in an area of the project premises where
areas of interest: (1)
resident farmer who lives in
surface soil or subsurface
subsurface soil has been remediated to the respective DCGLs and (2)
(2) the
the
person who spends time in the areas of the streams hiking, fishing, and hunting (the
This
in
recreationist). Th
is approach
approach is analogous
analogous to addressing
addressing multiple radionuclides
radionuclides in
contaminated media of interest
(NRC
contaminated
interest using the sum-of-fractions
sum-of-fractions approach or unity rule (NRC
2006).
Consideration
different areas led assigning
Consideration of potential
potential risks related to the different
assigning 90 percent
of the total dose limit of 25 mrem per year to the resident farmer
farmer activities
activities and 10
10 percent
percent to
activities.. This arrangement
arrangement involves
22.5
the recreational
recreational activities
involves assigning an acceptable
acceptable dose of 22
.5
mrem per year to resident
resident farmer activities
activities and 2.5 mrem per year to recreation
recreation in the area
area
16
of the streams, values
values which total 25 mrem per year.
year.1
6 The assessment
assessment was then
performed using the base case analysis results for the resident farmer and the recreationist
performed
at Erdman Brook and Franks Creek.
•
Two separate assessments were performed
performed with the resident farmer located
located in:
in : (1) the
the
area of the remediated
remediated WMA
subsurface soil excavation,
WMA 1 subsurface
excavation, and (2) the resident
resident farmer
located
remediated.. Details
located in an area where surface
surface soil was assumed to have been remediated
Details
appear in Appendix C.
C.
5.3.3
Results of the Assessments
Assessments
subsurface soil case and
Table 5-12 provides the assessment
assessment results for the WMA 1 subsurface
Table
Table 5-13 provides the results for the surface
surface soil case. The streambed
streambed sediment DCGLw
DCGLw
values are the same in both cases because the apportioned
apportioned dose limit of 2.5
2.5 mrem per
year is the same.
16
This 0.9010.10
0.90/0.10 split
is based
judgment related
related to
relative risk.
Consideration was
16 This
split is
based on
on judgment
to relative
risk. Consideration
was given
given to
to using a split
split
based on
on the
the relative
relative time the
the hypothetical
hypothetical farmer would
would spend
spend in
in the
the area of the
the farm compared to
to the area
area
of the streams.
However, because
because the
the assumed time
time in
in the
the area of
of the streams is
is relatively
small at 104
of
streams . However,
relatively small
104
hours per year, such as spilt could result in
in an allowable
allowable annual dose of 24.7 mrem for resident farmer
activities and 0.3 mrem for recreation at the streams.
streams . This split would have a minimal impact on the soil
DCGLs while driving the streambed sediment DCGLs to unrealistically
unrealistically low levels.
Revision
Revision 2
5-58
5-58
•
WVDP PHASE 1 DECOMMISSIONING
DECOMMISSIONING PLAN
•
•
Table 5-12.
Site-Wide Dose Assessment 1I Results (DCGLs in pCi/g)
5-12. Limited Site-Wide
Nuclide
Nuclide
Subsurface
DCGLw
Subsurface Soil
DCGL
w Values
Base Case(1 )
Assessment(2)
Base Case(1)
Assessment(2)
Streambed
DCGLw
Streambed Sediment DCGL
Values
w Values
1
Base Case(
Assessment(2)
Base
Case(1))
Assessment(2)
Am-2411
Am-24
6.3E+03
5.7E+03
C-1 4
C-14
9.9E+02
9.9E+02
8.9E+02
8.9E+02
1.8E+03
1.8E+03
1.8E+02
1.8E+02
Cm-243
Cm-243
1.1E+03
9.9E+02
9.9E+02
3.1E+03
3.1E+03
3.1E+02
3.1E+02
Cm-244
2.2E+04
2.OE+04
2.0E+04
3.8E+04
3.8E+04
3.8E+03
3.8E+03
3
Cs-137(3)
Cs-137( )
3.0E+02
2.7E+02
1.0E+03
1.OE+03
1.0E+02
1.OE+02
1-129
1-129
Np-237
Np-237
7.5E+00
7.5E+OO
1.OE+00
1.0E+OO
6.8E+00
6.8E+OO
9.0E-01
7.9E+02
7.9E+02
3.2E+02
3.2E+02
7.9E+01
3.2E+01
Pu-238
Pu-239
1.3E+04
3.1E+03
1.2E+04
2.8E+03
2.8E+03
1.2E+04
1.2E+04
1.2E+03
1.2E+03
1.2E+04
1.2E+04
1.2E+03
1.2E+03
Pu-240
Pu-240
Pu-241
Pu-241
3.4E+03
2.4E+05
3.1E+03
3.1
E+03
2.2E+05
2.2E+05
1.2E+04
1.2E+04
1.2E+03
1.2E+03
3.4E+05
3.4E+05
3.4E+04
3.4E+04
Sr-90(3)
Sr-90(3)
2.8E+02
2.5E+02
2.5E+02
4.7E+03
4.7E+02
Tc-99
5.9E+02
5.3E+02
5.3E+02
6.6E+05
6.6E+05
6.6E+04
6.6E+04
U-232
U-232
U-233
7.4E+01
1.9E+02
6.7E+01
6.7E+01
1.7E+02
1.7E+02
2.2E+02
2.2E+02
2.2E+04
2.2E+04
2.2E+01
2.2E+03
2.2E+03
U-234
2.0E+02
1.8E+02
1.8E+02
2.2E+04
2.2E+04
2.2E+03
2.2E+03
U-235
2.1E+02
2.1
E+02
2.1
2.1E+02
1.9E+02
1.9E+02
2.3E+03
2.3E+03
8.2E+03
8.2E+03
2.3E+02
2.3E+02
8.2E+02
U-238
1.0E+04
1.OE+04
1.0E+03
1.OE+03
NOTES:: (1)
(1) The base-case values for subsurface soil are
5-1 lcc and the base-case
base-case
NOTES
are the lowest
lowest values
val ues from
from Table 5-11
5-1111 a.
values for streambed
streambed sediment are
are the lowest values from Table
Table 5a.
(2) The results for the analysis
combined
in th
this
in the
the
analysis of the com
bined base-case in
is table (the lowest
lowest DCGLs in
(2)
analyses for subsurface
recreationist in
in the area of the
th e streams.
stream s.
various analyses
subsurface soil) and the recreationist
(3) These DCGLs
DCGLs apply in
in the
th e year 2041 and later.
5-13, the dose partitioning
DCGLw
As can be seen from Table 5-13,
partitioning approach reduced the DCGL
w
values for surface soil by 10 percent and reduced
DCGLww values for streambed
reduced the DCGL
magnitude.
sediment by an order of magnitude.
Table 5-13. Limited Site-Wide
Site-Wide Dose
Dose Assessment
Assessment 2 Results (DCGLs in pCi/g)
Nuclide
Nuclide
•
Surface Soil DCGLw
DCGLw Values
1
Base Case(
Case(1)
Assessment(2
Assessmentf 2 )
Values
Streambed Sediment DCGLw
DCGLw Values
1
Base Case(1)
Assessment(2)
Base
Case( )
Am-241
2.9E+01
2.6E+01
2.6E+01
1.OE+04
1.0E+04
1.0E+03
1.0E+03
C-14
14
C-
1.6E+01
1.6E+01
1.5E+01
1.5E+01
1.8E+03
1.8E+03
1.8E+02
Cm-243
3.5E+01
3.5E+01
3.1E+01
3.1
E+01
3.1E+03
3.1E+02
Cm-244
Cs-137(3)
Cs-137(3)
6.5E+01
6.5E+01
5.8E+01
3.8E+04
3.8E+03
1.5E+011
1.5E+0
1.4E+01
1.4E+01
1.OE+03
1.0E+03
1.0E+02
1.0E+02
1-129
1
-129
3.3E-01
2.9E-01
7.9E+02
7.9E+01
Np-237
2.6E-01
2.3E-01
3.2E+02
3.2E+01
Pu-238
4.0E+01
3.6E+01
1.2E+04
1.2E+04
1.2E+03
1.2E+03
Revision
Revision 2
5-59
5-59
WVDP PHASE
PHASE 11 DECOMMISSIONING
DECOMMISSIONING PLAN
P LAN
WVDP
Table 5-13.
5-13. Limited
limited Site-Wide
Site-Wide Dose
Dose Assessment
Assessment 2 Results
Results (DCGLs
(DCGLs in pCi/g)
pCi/g)
Table
Nuclide
Nuclide
Surface
Surface Soil
Soil DCGLw
DCGLw Values
Values
1
Assessment(2)
Base Case(
Case(1)
Base
Streambed
Streambed Sediment
Sediment DCGLw
DCGLw Values
Values
1
Assessment(2)
)
Case(
Base
Base Case(1)
Assessment(2)
Pu-239
Pu-239
2.5E+01
2.5E+01
2.3E+01
2.3E+01
1.2E+04
1.2E+04
1.2E+03
1.2E+03
Pu-240
Pu-240
2.6E+01
2.6E+01
2.4E+01
2.4E+01
1.2E+04
1.2E+04
1.2E+03
1.2E+03
Pu-241
Pu-241
1.2E+03
1.2E+03
1.OE+03
1.0E+03
3.4E+05
3.4E+05
3.4E+04
3.4E+04
Sr-90(3)
Sr-90(3)
4.1
4.1E+00
E+OO
3.7E+00
3.7E+00
4.7E+03
4.7E+03
4.7E+02
4.7E+02
Tc-99
Tc-99
2.1E+01
2.1E+01
1.9E+01
1.9E+01
6.6E+05
6.6E+04
6.6E+04
U-232
U-232
1.5E+00
1.5E+00
1.4E+00
1.4E+00
2.2E+02
2.2E+01
U-233
U-233
8.3E+00
7.5E+00
7.5E+00
2.2E+04
2.2E+03
2.2E+03
U-234
U-234
U-235
8.4E+00
7.6E+00
2.2E+04
2.2E+04
2.2E+03
2.2E+03
3.5E+00
3.1E+00
3.1E+OO
2.3E+03
2.3E+02
2.3E+02
U-238
9.8E+00
8.9E+00
8.2E+03
8.2E+02
8.2E+02
•
lla,
NOTES:
(1) The
NOTES : (1)
The base-case
base-case values
values are the lowest
lowest values from
from Table
Table 5-1
5-11a.
th e combined
combined base
base case in this
this table
table (the lowest DCGLs in
in the various
various
(2) The
Th e results
results for the analysis of the
streams.
analyses
analyses for subsurface
subsurface soil) and
and the
th e recreationist
recreationist in
in the area of the streams.
(3) These
These DCGLs
DCGLs apply
apply in
in the year
year 2041
204 1 and
and later.
later.
(3)
5.4
Cleanup
Cleanup Goals and Additional
Additional Analyses
Analyses
remediation of surface
This section (1)
(1) identifies the cleanup goals to be used
used in remediation
surface soil,
soil ,
goals; (2)
subsurface
subsurface soil,
soil , and streambed
streambed sediment
sediment and
and the basis
basis for these cleanup goals;
(2)
describes
describes how the DCGLs and the cleanup
cleanup goals will be later
later refined;
refined ; (3)
(3) discusses use
use of
surrogate
radionuclides;; and (4) identifies
surrogate radionuclides
identifies plans for the dose
dose assessment of the
the remediated
remediated
WMA 1 and WMA 22 areas.
areas.
5.4.1
Cleanup Goals
Goals
As explained
explained in
in Section
Section 5.1.6,
5.1.6, the dose
dose modeling
modeling process includes
includes establishing cleanup
cleanup
goals below the DCGLs developed
developed to meet the 25 mrem per year unrestricted
unrestricted dose limit
limit
that are to be used
used to guide remediation
remediation efforts,
efforts, considering the results of the analysis of
the combined source
source area exposure
exposure scenario
scenario described
described in Section 5.3
5.3 and the ALARA
ALARA
Section 6.
analysis described
described in Section
•
Analysis
Combined
Combined Source Area Analysis
5.3, analysis of the limiting scenario for dose integration
As indicated in Section 5.3,
integration - aa
remediated
resident farmer living on the remed
iated project premises
premises who spends time in the vicinity of
hiking, fish
fishing,
ing , and hunting - produced lower DCGLw
DCGLw
Erdman Brook and Franks Creek hiking,
in
the
area
of the
for
the
recreationist
groups, with the reduction
values for both critical groups,
reduction
the
percentage.
streams being a much greater
greater percentage.
Analysis
ALARA Analysis
soil,,
Section
Section 6 describes the process used to evaluate whether
whether remediation of surface soil
subsurface soil, and streambed sediment below DCGLs based on 25 mrem/y would be
be
subsurface
analyses. Section 6
standard NRC methodology for ALARA analyses.
cost-effective, following the standard
cost-effective,
Revision 2
5-60
5-60
•
WVDP PHASE 11 DECOMMISSIONING
DECOMMISSIONING PLAN
•
be
provides the results of a preliminary
preliminary analysis
analysis and provides
provides for a final ALARA analysis to be
decommissioning work.
work.
performed during
during the Phase 1 decommissioning
The preliminary ALARA
ALARA analysis suggests
suggests that the costs of removing slightly
contaminated soil or sediment at concentrations
concentrations below the DCGLs
DCGLs for 25 mrem
mrem per year
will outweigh the benefits. That is,
subsurface soil, and stream
is, areas where surface
surface soil, subsurface
remediated to radioactivity concentrations
sediment are remediated
concentrations at the DCGLs satisfy the ALARA
ALARA
criteria.. The evaluation
criteria
evaluation process balances the cost of offsite disposal of additional
radioactively contaminated
contaminated soil (cost of $6.76 per cubic foot) and the benefits of reduced
person-rem as set forth in NRC guidance).
dose (benefit of $2000 per person-rem
The final ALARA
decommissioning
ALARA analysis that will be performed
performed during the Phase 1 decommissioning
activities will make use of updated information
information,, such as actual rather than predicted waste
disposal costs.
costs. However, the results will likely be similar to the preliminary
preliminary analysis.
Section 6 explains that the methods to be used in remediation
remediation of contaminated
contaminated soil
and sediment, which involve excavation
excavation of the material in bulk quantities, will generally
generally
material than necessary
necessary to meet the DCGLs.
DCGLs. As noted in Section 6,
6, NRC
remove more material
recognizes
that
soil
excavation
is
a
coarse
removal
process
that
is
likely
to
remove
large
likely
large
recognizes
contaminated soil and sediment
fractions of the remaining
remaining radioactivity
radioactivity (NRC 1997). The contaminated
sediment
removal method is therefore
expected to produce residua
residuall radioactivity concentrations
concentrations well
therefore expected
below the DCGLs.
DCGLs.
Cleanup Goals
Goals
Cleanup
•
Demonstration that the decommissioning
Demonstration
decommissioning activities have achieved the desired
desired dosebased criteria is through the process described
Radiation Survey and
described in the Multi-Agency Radiation
Site Investigation Manual
Site
Manual (MARSSIM) (NRC 2000). This process is outlined in Section 9,
which describes
describes the general content of the Phase 1 Final Status
Plan.. The Phase 1
Status Survey Plan
Final Status Survey Plan provides
provides the details.
details.
For surface
surface soils and sediments in the WVDP Phase 1 areas, the field cleanup goal
need not be too far below the DCGL, ifif at all. As discussed previously,
previously, bulk excavation
excavation will
generally remove
necessary to meet the DCGL,
DCGL, so it is likely that the
remove more material
material than necessary
the
post-remediation
average concentration
chosen..
post-remediation average
concentration will be below whatever
whatever in-process
in-process goal is chosen
And the costs for additional
additional remediation
remediation of aa surface soil or sediment site,
site, while extra, are
not unusually high.
high .
However, for subsurface soils aa field cleanup
cleanup goal should be well below the DCGL
remediation were necessary
necessary to an
because of the large costs to be incurred if additional remediation
Re-excavating to depth with shoring, engineering
area that failed the statistical testing.
testing . Re-excavating
engineering
controls, and management
management or disposal of extensive overburden
overburden would be expensive
expensive
controls,
compared to excavating
excavating some additional material in the original remediation.
Consideration
goals
Consideration of such factors
factors led to DOE establishing in this plan the cleanup goals
soil cleanup goals apply only to areas of the
the
shown in Table 5-14. Note that the surface soil
project premises
premises where there is no subsurface
subsurface soil contamination
contamination and that the subsurface
subsurface
soil cleanup goals apply only to the bottoms and lower sides (extending from aa depth of
three feet and greater) of the large excavations
excavations in WMA 1 and WMA 2.
2.
•
Revision 2
5-61
DECOMMISSIONING PLAN
WVDP PHASE 1 DECOMMISSIONING
1
Remediation in
in pCi/g0
pCi/g(1 ))
Table 5-14. Cleanup Goals to be Used in Remediation
Streambed
Soil(3)
Subsurface Soil(3)
Surface Soil(2)
SOil(2)
Subsurface
Streambed Sediment(2)
Sediment(2)
Surface
Nuclide
CG.w
CG
CGEMC
CG
EMC
CGM
CG w
Am-241
Am-241
2.6E+01
3.9E+03
2.8E+03
C-14
1.SE+01
1.5E+01
1.6E+06
4.SE+02
4.5E+02
Cm-243
3.1E+01
3.1E+01
7.SE+02
7.5E+02
S.OE+02
5.0E+02
Cm-244
5.8E+01
S.8E+01
1.2E+04
9.9E+03
Cs-137(4)
1.4E+01
3.OE+02
3.0E+02
1.4E+02
1-129
1-129
2.9E-01
6.0E+02
6.0E+02
Np-237
Np-237
2.3E-01
2.3E-01
Pu-238
Pu-239
3.6E+01
2.3E+01
2.3E+01
Pu-240
2.4E+01
Pu-241
Pu-241
4
Sr-90(4)
CGEMC
CG
EMC
CG,w
CG
CGEMC
CG
EMC
1.2E+04
1.OE+03
1.0E+03
2.IE+04
2.1E+04
8.OE+04
1.8E+02
1.8E+02
S.9E+OS
5.9E+05
4.0E+03
4.OE+03
3.1E+02
3.1E+02
2.8E+03
4.5E+04
4.SE+04
3.8E+03
3.8E+03
3.6E+05
3.6E+OS
1.7E+03
1.OE+02
1.0E+02
9.4E+02
3.4E+00
3.4E+OO
3.4E+02
7.9E+01
7.9E+01
2.OE+04
2.0E+04
7.5E+01
7.SE+01
4.5E-01
4
.SE-01
4.3E+01
3.2E+01
1.1E+03
1.1E+03
7.6E+03
S.9E+03
5.9E+03
2.8E+04
1.2E+03
6.9E+03
1.4E+03
2.6E+04
1.2E+03
1.7E+05
1.7E+OS
1.7E+05
1.7E+OS
6.9E+03
1.5E+03
1.SE+03
2.6E+04
1.2E+03
1.7E+05
1.7E+05
1.OE+03
1.0E+03
1.3E+05
1.1E+05
E+OS
1.1
6.8E+05
3.4E+04
7.5E+05
Sr-90( )
3.7E+00
3.7E+OO
7.9E+03
1.3E+02
1.3E+02
7.3E+03
4.7E+02
7.1E+04
Tc-99
1.9E+01
2.6E+04
2.7E+02
1.5E+04
6.6E+04
4.2E+06
U-232
U-232
U-233
U-233
1.4E+00
1.4E+OO
5.9E+01
3.3E+01
4.2E+02
2.2E+01
7.5E+00
7.5E+OO
8.OE+03
8.6E+01
9.4E+03
2.2E+03
2.1E+02
2.1E+02
4.4E+04
U-234
7.6E+00
7.6E+OO
1.6E+04
1.6E+04
9.0E+01
9.4E+03
2.2E+03
2.1E+05
2.1E+OS
U-235
3.1E+00
3.1E+OO
6.1E+02
9.5E+01
9.SE+01
3.3E+03
2.3E+02
2.OE+03
2.0E+03
U-238
U-238
8.9E+00
8.9E+OO
2.9E+03
9.5E+01
9.SE+01
9.9E+03
8.2E+02
8.2E+03
NOTE:
NOTE: (1)
These cleanup goals (CGs) are
are to be used as
as the criteria for
for the remediation activities descnbed
described in
in
sediment cleanup
cleanup goals will support
Section 7 of this
th is plan.
plan. Note
Note that the streambed sediment
support unrestricted
unrestricted
release of the project
project premises but will not necessarily
necessarily support restricted release alternatives
alternatives due to
continued
5.2.2.
the con
tinued presence of Phase 2 sources as discussed in Section 5.2.2.
surface soil and streambed sediment
dose
values for surface
sediment are
are the same
same as the limited dose
(2) The CGw
CG w values
assessment
5-13,
values
assessment DCGL values in the third and fifth columns
columns of Table
Table 5·
13. respectively.
respectively . The CGEMC
CG EMC values
are based on the limiting case among the probabilistic analysis resident farmer
analysis, the
farmer analysis.
analysis, and the deterministic residential
residential gardener analysis.
analysis.
deterministic resident
resident farmer analysis.
factor
reduced by aa fa
ctor
(3) These CGw
CGw values are the assessment values in the third column of Table 5-12 reduced
of 0.50 as discussed
below. The DCGL
DCGLEMc
discussed below.
EMc values are the limiting values from the multi-source
farmer/residential gardener
analysis or the deterministic
deterministic resident farmerlresidential
gardener deterministic analyses using the 1
m22 area factor from Table 9-2.
the
9-2. The subsurface
subsurface soil cleanup
cleanup goals apply only to the bottoms of the
m
WMA 1 and WMA 22 deep excavations
excavations and to the sides of these excavations more than three feet
surface.
below the ground
ground surface.
is, they incorporate
incorporate a
(4) The cleanup goals for Sr-90 and Cs-137 apply to the year 2041
204 1 and later,
later. that is.
30-year decay
2011.. The 30-year
selected for these key radionuclides
radionuclides
30-yea r decay period was selected
decay period from 2011
because of their short half-life.
half-life. As noted previously,
previously. the Phase
Phase 2 decision
decision could be made within 10
decision.
years of issue of the Record of Decision and Findings Statement
Statement documenting
documenting the Phase 1 decision.
If this approach were to involve unrestricted
unrestricted release
site, achieving this condition
be
release of the site.
condition would be
If
expected to take more than 20 years due to the large scope of effort to exhume the underground
waste
It is therefore
therefore highly unlikely that conditions for unrestricted
unrestricted release of the
the
waste tanks and the NDA. It
project premises could be established
established before 2041,
2041 . If
If Phase 2 were to involve closing radioactive
radioactive
place, then institutional
2041.. DOE will be responsible
responsible
facilities in place.
institutional controls would remain in place after 2041
maintaining
monitoring and
for mainta
ining institutional control of the project premises and providing for monitoring
maintenance of the project
project premises
premises until completion of Phase 22 of the decommissioning.
decommissioning .
maintenance
•
0
0
•
The basis for these cleanup
cleanup goals is as follows. Compliance
Compliance with the cleanup
cleanup goals
present will be determined
determined by use
radionuclides are present
used for remediation
remediation when mixtures of radionuclides
of the sum-of-fractions approach
approach..
Revision 2
Revision
5-62
5-62
•
WVDP PHASE 1 DECOMMISSIONING
DECOMMISSIONING PLAN
•
Basis for Cleanup Goals for Surface
Surface Soil
The surface
CGw
DCGL w Assessment
Assessment
surface soil CG
values in the Surface Soil DCGLw
w values are the values
5-13 . DOE considers these goals to be conservative
conservative and appropriate
appropriate to
column of Table 5-13.
remediation of surface
surface soil and sediment in drainage ditches on
on
provide assurance
assurance that any remediation
the project premises
premises that may be accomplished during Phase 1 of the decommissioning
decommissioning will
20.1402, should the
the
support releasing the remediated areas
areas under
under the criteria of 10 CFR 20.1402,
eventually
determine
that
appropriate
licensee eventually
determine
approach
to
be
appropriate
the
for
Phase
2
of
the
17
decommissioning..17
decommissioning
Basis for Cleanup Goals for Subsurface Soil
DOE has established the subsurface soil cleanup goals at 50 percent
percent of subsurface soil
DCGLs calculated in the limited site-wide dose assessments for 22.5
22.5 mrem per year (Table
(Table
5-12).
5-12). The cleanup goals for subsurface
subsurface soil will therefore equate to 11.25 mrem per year.
approach to provide
DOE is taking this approach
provide additional
additional assurance
assurance that remediation
remediation of the WMA 1
and WMA 2 excavated
excavated areas will support all potential options for Phase 2 of the
the
decommissioning.
As
indicated
previously,
these
cleanup goals apply only to the bottom
bottom of
decommissioning .
previously,
the large WMA 1 and WMA 2 excavations and to the sides of these excavations
excavations three feet
or more below the surface.
surface.
Streambed Sediment
Basis for Cleanup Goals for Streambed
Sediment
DCGLw
site-wide dose assessment (the last
DOE has used the DCGL
w values from the limited site-wide
column in Table 5-12 and Table 5-13) as the cleanup
goals
for streambed sediment. These
These
cleanup
values are substantially less than those developed
developed for the base-case
recreationist scenario
base-case recreationist
and are considered
considered to be supportive of any approach that may be selected for Phase 2 of
decommissioning.
the decommissioning.
•
As noted in the discussion on the ALARA analysis results, DOE expects that the actual
levels of residual
remediation,,
residual radioactivity
radioactivity will turn out to be less than the DCGLs used for remediation
i.e.,
be
i.e., these cleanup
cleanup goals,
goals, owing to the characteristics
characteristics of the remediation method to be
used.
5.4.2
Refining DCGLs and Cleanup
Cleanup Goals
Goals
The calculated DCGLs for 25 mrem per year and the associated cleanup goals will be
be
refined
as
appropriate
after
the
data
from
the
soil
and
sediment
characterization
program
refined
sediment characterization program to
be completed early in Phase 1 of the decommissioning becomes
becomes available. These data are
expected to provide additional
additional insight into the radionuclides
radionuclides of interest in environmental
media and the depth and areal distribution of the contamination.
contamination . Such information could,
could , for
example,
lead
to
deleting
one
or
more
radionuclides
from
further
consideration
in
the
Phase
example,
deleting
more radionuclides
consideration
1 cleanup or lead to more realistic source geometry for development
development of DCGLs for surface
surface
soil
contamination.. Analytical data from the subsurface
characterization measurements
measurements
soil contamination
subsurface soil
soil characterization
being taken in 2008
2008 could also provide information to help
help refine the subsurface soil
DCGLs.
DCGLs.
As noted previously, surface soil may or may not be remediated in Phase 1 of the decommissioning.
As noted previously, surface soil mayor may not be remediated in Phase 1 of the decommissioning.
However,
characterization performed early in
However, it
it is
is possible
possible that
that characterization
in Phase 1 could identify surface soil
contamination that
that would warrant
warrant remediation to
to reduce radiation doses during the period between Phase 1
contamination
and Phase 2 of the decommissioning.
decommissioning. In
In the unlikely
developed, the areas of
unlikely event
event that this situation developed,
concern
remediated in
in Phase 1.
concern would be remediated
17
17
•
Revision 2
5-63
5-63
WVDP PHASE 1 DECOMMISSIONING
DECOMMISSIONING PLAN
If
leads to refinement of the DCGLs and cleanup
cleanup goals, then
If evaluation of the new data leads
accordingly to reflect the new values.
this plan will be revised accordingly
values. Since such a change could
affect the project end conditions,
conditions, the plan revision would be provided
provided to NRC for review and
input prior to issue following the change
change process described in Section 1.
5.4.3
Use of a Surrogate
Surrogate Radionuclide DCGL
•
A surrogate
radionuclide is aa radionuclide
surrogate radionuclide
radionuclide in a mixture of radionuclides whose
concentration
measured and can be used to infer
concentration is easily measured
infer the concentrations
concentrations of the other
radionuclides
If actual radioactive
radionuclides in the mixture.
mixture. If
radioactive contamination
contamination levels
levels of the surrogate
surrogate
radionuclide
are
below
the
specified
concentration,
then
the
sum
radionuclide
below
concentration ,
of doses from all
18
radionuclides
limit.18
radionuclides in the mixture will fall below the dose limit.
The tables in this section do not provide DCGLw
surrogate radionuclide
radionuclide
DCGL w values for aa surrogate
because
radionuclide distributions
distributions in soil and sediment are not sufficient
because available data on radionuclide
However, surrogate radionuclide
DCGLw
cleanup goals will
to support this.
this. However,
radionuclide DCGL
w values for the cleanup
be developed
incorporated into this section ifif evaluation
additional characterization
developed and incorporated
evaluation of additional
data shows that Cs-137 or another easy
easy to measure
measure radionuclide
radionuclide can be used effectively as
as
a surrogate for all radionuclides
in source
radionuclides in
source soil,
soil , subsurface
subsurface soil,
soil , and/or
and/or streambed
sediment
streambed sediment
in an area.
area.
5.4.4
Preliminary
Assessment
Preliminary Dose Assessment
Preliminary dose assessments
assessments have been performed
performed for the remediated WMA
WMA 1 and
WMA 2 excavations. These assessments made use of the maximum
maximum measured
radioactivity concentration in the Lavery till for each radionuclide
radionuclide as summarized in Table 51, and the results of modeling
modeling to develop DCGLs for 25 mrem per year and the multisource analysis results as shown in Table 5-1
5-11lc.
c. The results were as follow:
WMA 1, a maximum
maximum of approximately
approximately 88 mrem a year
WMA 2,
2, a maximum
approximately 0.2
maximum of approximately
0.2 mrem a year
Given
Given the limited data available,
available, these results must be viewed as order-of-magnitude
order-of-magnitude
estimates. However, they do suggest that actual potential doses from the two remediated
remediated
areas
areas are likely to be substantially
substantially below 25 mrem per year. Note that the primary
primary dose
dose
driver
approximately 66 percent of the
the
driver for these estimates
estimates is Sr-90,
Sr-90, which accounts for approximately
estimated dose for the WMA 1 excavation and approximately
approximately 61 percent of the estimate for
the WMA 2 excavation.
excavation .
•
NOTE
NOTE
The use of maximum rather than average values in these dose estimates adds
adds
conservatism,
including values that are simply
detectable
conservatism, as does including
simply the highest minimum detectable
concentrations, especially in the case of Np-237.
Np-237. (There was a wide range of several
orders of magnitude among the minimum detectable
detectable concentrations
concentrations reported
reported for the
the
2008 sample data.)
data.) As with the DCGLs,
DCGLs, decay of Sr-90 and Cs-137 over 30 years is
accounted
accounted for in the estimate.
18 Guidance on the use of surrogate measurements provided in Section 4.3.2 of NUREG-1575, Multi-Agency
Guidance on the use of surrogate measurements provided in Section 4 .3.2 of NUREG-1575, Multi-Agency
Radiation Survey
Survey and Site Investigation
Investigation Manual
(NRC 2000) would
would be
be followed
followed..
Radiation
Manual (MARSSIM)
(MARSSIM) (NRC
18
Revision 2
5-64
•
WVDP PHASE 1 DECOMMISSIONING
DECOMMISSIONING PLAN
•
As noted previously,
previously, DOE will perform
residual radioactivity
perform aa dose assessment
assessment for the residual
excavated areas using Phase 1 final status survey data
data.. This
in the WMA 1 and WMA 2 excavated
This
assessment will use the same methodology used in
in development
subsurface soil
development of the subsurface
DCGLs to estimate
estimate the potential radiation dose using the actual measured residual
radioactivity concentrations. The results of the dose assessment
radioactivity
assessment will be made available to
stakeholders. Note that a more-comprehensive
more-comprehensive dose assessment
NRC and other stakeholders.
assessment that also
performed in connection with Phase 2 of
takes into account
account the Phase 22 sources may be performed
phase.
depending on the approach selected for that phase.
the decommissioning,
decommissioning, depending
5.5
Monitoring,
Controls
Monitoring, Maintenance,
Maintenance, and Institutional Controls
Inherent in the use of the 30-year
30-year decay period used
used in development
development of DCGLs and
cleanup goals for Sr-90 and Cs-137
Cs-137 is the assumption that all or part of the project
unrestricted use before 2041.
2041 . DOE will be responsible for
premises will not be released for unrestricted
maintenance of the project premises and for maintaining institutional
monitoring and maintenance
controls until completion
completion of Phase 2 of the WVDP decommissioning,
decommissioning, which is assumed to
to
If aa
occur after 2041 if
unrestricted release criteria.
if Phase
Phase 2 were to be designed to meet unrestricted
criteria . If
2, then institutional controls are assumed
close-in-place
close-in-place approach
approach was selected for Phase 2,
to be required beyond 2041.
2041 .
5.6
References
References
Code of Federal
Federal Regulations
Regulations
CriteriaFor
Termination (LTR).
10 CFR 20, Subpart E, Radiological
Radiological Criteria
For License Termination
(L TR) .
•
10 CFR 20.1003,
20 .1003, Definitions.
Definitions.
DOE Orders
Orders
U.S,
ProtectionProgram,
DOE Order 450.1,
450.1, Environmental
Environmental Protection
Program, including
including Changes 1 and 2. U.S,
Energy, Washington,
2003..
January 15, 2003
Department of Energy,
Washington, D.C. January
and the Environment,
Radiation Protection
DOE Order 5400.5, Radiation
Protection of the Public
Public and
Environment, Change
Change 2.
U.S,, Department
Washington, D.C., January 7, 1993.
1993.
U.S
Department of Energy,
Energy, Washington,
DOE Technical
Technical Standards
Standards
1153-2002, A Graded
GradedApproach for Evaluating
Evaluating Radiation
Doses to Aquatic
DOE Standard
Standard 1153-2002,
Radiation Doses
and Terrestrial
TerrestrialBiota.
U.S, Department
Department of Energy, Washington,
and
Biota. U.S,
Washington , D.C., July
July 2002.
2002 .
Other
Other References
References
ParameterAnalysis,
Analysis,
Radioactivity from Decommissioning,
Decommissioning, Parameter
Beyeler, et al. 1999, Residual
Residual Radioactivity
A.
NUREG/CR-5512, Vol 3, Draft Report for Comment. Beyeler, W.
W. E., W.
W. A.
NUREG/CR-5512,
T. J.
Brown, E. Kalinina, D. P. Gallegos,
Hareland, F.
F. A.
A. Duran,
Duran , T.
J. Brown,
Gallegos, and P. A. Davis,
Mexico, October
Sandia
Sandia National Laboratories, Albuquerque,
Albuquerque, New Mexico,
October 1999.
Dames and Moore 1994, North
North Plateau
Plateau Groundwater
Groundwater Seepage Survey, Letter Report
D&M:SPV:PJG:1
1B:0249. Dames and Moore, West Valley New York,
D&M
:SPV:PJG :11B:0249.
York , August 15,
15,
1994.
•
Revision 2
5-65
5-65
WVDP
WVDP PHASE
PHASE 1 DECOMMISSIONING
DECOMMISSIONING PLAN
PLAN
DOE
DOE 2004,
2004, Users Guide, RESRAD-BIOTA:
RESRAD-BIOTA : A
A Tool for Implementing a Graded
Graded Approach
Approach to
to
Biota Dose Evaluation,
Evaluation , Version
Version 1,
1, DOE/EH0676.
DOE/EH0676. Environmental
Environmental Assessment
Assessment
Division,
Division, Argonne
Argonne National
National Laboratory,
Laboratory, Argonne,
Argonne , Illinois,
Illinois, January
January 2004.
2004.
EPA 1997,
1997, Exposure
Exposure Factors
Factors Handbook. National
National Center for
for Environmental
Environmental Assessment,
Assessment,
S. Environmental
Environmental Protection
Protection Agency,
Agency,
Office of
of Research
Research and
and Development,
Development, U. S.
Office
Washington , D.C.,
D.C. , 1997.
1997.
Washington,
•
Hemann
of the Core Area
Area of the North
Hemann and
and Steiner
Steiner 1999,
1999, 1998 Geoprobe
Geoprobe Investigation
Investigation of
Plateau
Plateau Groundwater
Groundwater Plume,
Plume , WVDP-346,
WVDP-346, Revision
Revision 0.
O. Hemann,
Hemann , M.R. and
and R.E.
R.E.
Steiner II,
II , West
West Valley Nuclear
Nuclear Services Company,
Company, June
June 11,
11 , 1999.
1999.
Dispersion of Effluents
NRC
NRC 1977, Estimating
Estimating Aquatic
Aquatic Dispersion
Effluents from Accidental and Routine Reactor
Regulatory Guide
Releases for the Purpose
Appendix I,
I, Regulatory
Guide 1.113,
1.113,
Purpose of Implementing Appendix
Rev. 1. U.S.
U.S. Nuclear
Nuclear Regulatory
Rev.
Regulatory Commission,
Commission, Office
Office of
of Standards
Standards Development,
Development,
Washington,
D.C.,, April 1977.
1977.
Washington , D.C.
Environmental Impact Statement in Support of
NRC
Generic Environmental
of Rulemaking on
NRC 1997,
1997, Generic
NRC-Licensed
Nuclear
for
License
Termination
of
Radiological
Criteria
Radiological Criteria
Termination
Nuclear Facilities;
Facilities;
Regulatory Commission,
U.S. Nuclear
Nuclear Regulatory
Final
Final Policy Statement. NUREG-1496,
NUREG-1496, Vol.
Vol. 1.
1. U.S.
Regulatory Research,
Office of
of Regulatory
Research, Division of Regulatory
Regulatory Applications, Washington,
Washington ,
1997.
D.C., July
July 1997.
Radiation Survey and Site Investigation
NRC
NRC 2000, Multi-Agency Radiation
Investigation Manual (MARSSIM),
(MARSSIM) ,
2000.. (Also EPA 4-2-RNUREG-1575, Revision 1. NRC,
August, 2000
4-2-RNUREG-1575,
NRC, Washington,
Washington, DC, August,
DOE-EH-0624,
U.S. Environmental
97-016,
97-016, Revision
Revision 1, U.S.
Environmental Protection Agency and
and DOE-EH-0624,
1, DOE)
DOE)
Revision 1,
NRC 2006, Consolidated
Consolidated NMSS
NMSS Decommissioning
Decommissioning Guidance:
Guidance: Characterization,
Characterization, Survey,
Criteria,Final
and Determination
Radiological Criteria,
Final Report, NUREG
NUREG 1757 Volume 2,
and
Determination of Radiological
Washington,
Material
Safety
and
Safeguards,
NRC,
Office
of
Nuclear
Revision
1.
Revision 1.
Office
Nuclear Material
Washington ,
DC, September, 2006.
2006.
•
Calculation Package,
Package, Estimates
EIS/DPlan Calculation
2009, West Valley EIS/DPlan
Price 2009,
Estimates of Human
Human Health
Health
the Excavation
Due to a Sub-surface
Sub-surface Source
Source in the Vicinity of the
Impacts
Impacts Due
Excavation of the Main
J., Science
Science
DPlan-SAIC-JDP-003. Price,
Plant
Process Building, Calculation
Plant Process
Calculation DPlan-SAIC-JDP-003.
Price , J.,
2009.
Maryland,
October
Corporation,
Germantown,
Applications
International
Appl ications
Corporation , Germantown , Maryland,
2009.
8.10),, University
Manual for SIBERIA
(Version 8.10)
2000, User
User Manual
Willgoose 2000,
SIBERIA (Version
University of Newcastle, New
Australia,
July
2000.
South Wales,
Wales,
Environmental
Demonstration Project
WVES and URS 2009,
2009, West Valley Demonstration
Project Annual Site Environmental
and URS
URS
Valley
Environmental
Services
Calendar Year 2008. West
Report, Calendar
Report,
Environmental
Inc.,, West Valley,
Valley, New York,
Group, Inc.
York, September 2009.
Part 4
Ill Hydrology
Information Document
Document Volume III
1993a. Environmental
Environmental Information
WVNSCO 1993a.
Hydrology Part
0. West
and Geochemistry,
Geochemistry, WVDP-EIS-009, Revision O.
Groundwater Hydrology
Hydrology and
Groundwater
19, 1993.
Valley Nuclear Services Company, West Valley, New York, February 19,1993.
Revision 2
5-66
•
DECOMMISSIONING PLAN
WVDP PHASE 1 DECOMMISSIONING
•
WVNSCO 1993b, Environmental
Environmental Information
Information Document
Document Volume I,
Geology, WVDP-EISWVDP-EISI, Geology,
004, Revision O.
0. West Valley Nuclear Services Company, West Valley, New York,
April 1, 1993.
WVNSCO
Information Document,
WVNSCO 1994, Environmental
Environmental Information
Document, Volume IV: Soils Characterization,
Characterization,
WVDP-EIS-008,
Nuclear Services Company, West Valley,
O. West Valley Nuclear
WVDP-EIS-008, Revision
Revision 0.
New York, September 15, 1994.
Conservationand Recovery Act Facility
Facility Investigation
Investigation
WVNSCO and D&M 1997, Resource Conservation
Report, Volume 4: Low-level Waste Treatment
Treatment Facility,
Facility, West Valley Demonstration
Demonstration
Report,
Project, West Valley,
Valley, New York, WVDP-RFI-021,
WVDP-RFI-021, Revision
Revision 0.
O. West Valley Nuclear
Nuclear
Project,
Services Company, West Valley, New
New York and Dames and Moore, Orchard
Orchard Park,
January 17,1997.
17, 1997.
New York, January
Yager
Simulation of Groundwater
GroundwaterFlow Near
Near the Nuclear
Facility at the
Yager 1987, Simulation
Nuclear Reprocessing
Reprocessing Facility
Western New York Nuclear
Nuclear Service Center,
Center, Cattaraugus
Cattaraugus County,
County, New York,
Geological
Investigations Report 85-4308. Yager, R.M,
Geological Survey Water
Water Resources Investigations
Geological Survey, U.S. Department
U.S. Geological
Department of Interior, Washington, D.C.,
D.C., 1987.
1987.
Support Modeling the Impacts
Impacts of Radioactive
Radioactive
Yu, et al. 1993, Data
Data Collection
Collection Handbook
Handbook to Support
Material
Environmental and Information
Information
aI., Environmental
Material in Soil, ANL/EAIS-8.
ANUEAIS-8. Yu, C., et al.,
Sciences
National Laboratory,
Laboratory, Argonne, Illinois, April 1993.
Sciences Division, Argonne National
•
•
Yu, et al. 2000, Development
Development of Probabilistic
Probabilistic RESRAD
and RESRAD-BUILD 3.0
RESRAD 6.0 and
Computer
Codes, NUREG/CR-6697,
NUREG/CR-6697, ANL/EAD/TM-98.
Computer Codes,
ANUEADITM-98. Yu,
Yu, C., et al.,
aI.,
Environmental
Environmental Assessment Division, Argonne National Laboratory, Argonne,
Illinois,
Illinois, November 2000.
Yu, et al. 2001,
2001, User's
User's Manual
ANUEAD-4. Yu, C., et al.,
aI.,
Manual for RESRAD
RESRAD Version 6, ANL/EAD-4.
Environmental
Environmental Assessment Division, Argonne National Laboratory, Argonne,
Illinois, July 2001.
2001.
Revision 2
5-67
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