WYLFA NUCLEAR POWER STATION  NON‐TECHNICAL SUMMARY    OF THE ENVIRONMENTAL STATEMENT 

WYLFA NUCLEAR POWER STATION NON‐TECHNICAL SUMMARY OF THE ENVIRONMENTAL STATEMENT 2013 UPDATE WYLFA NUCLEAR POWER STATION
NON-TECHNICAL SUMMARY
OF THE ENVIRONMENTAL STATEMENT
2013 UPDATE
in Support of the Application to Decommission Wylfa Nuclear Power Station as Required by
Statutory Instrument 1999 No. 2892: Nuclear Reactors (Environmental Impact Assessment for
Decommissioning) Regulations 1999 (as amended)
Issue One
March 2013
Published in the United Kingdom by Magnox Limited, Wylfa Nuclear Power Station, Cemaes Bay, Isle
of Anglesey, LL67 0DH.
All rights reserved. No part of this publication may be: (i) reproduced used, dealt with, possessed or
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Printed copies of the Welsh version of this document can be obtained from the following address:
Document Centre, Magnox, Wylfa Power Station, Cemaes Bay, Isle of Anglesey, LL67 0DH.
© Magnox Ltd 2013
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TABLE OF CONTENTS
1.
1.1.
INTRODUCTION: HOW AND WHY IS WYLFA APPLYING FOR CONSENT TO
DECOMMISSION?
Background to the Application to Decommission Wylfa
6
6
1.2.
Approach to Gaining Consent
7
1.3.
Stakeholder Engagement
7
1.4.
Method for the 2013 Update
8
2.
2.1.
THE WYLFA SITE
The Site Surroundings
9
10
3.
3.1.
THE DECOMMISSIONING PROJECT
How Will the Work be Managed?
11
12
3.2.
4.
4.1.
4.2.
Change in Decommissioning Strategy since 2008
WHAT DEVELOPMENT PROJECTS IN THE WYLFA AREA COULD AFFECT OUR
PLANS?
Nuclear New-Build
Other Infrastructure projects in Anglesey
14
14
14
14
5.
THE ROLE OF THE ENVIRONMENTAL MANAGEMENT PLAN (EMP)
15
6.
THE ENVIRONMENTAL IMPACT ASSESSMENT
16
6.1.
AIR QUALITY AND DUST
16
6.2.
ARCHAEOLOGY AND CULTURAL HERITAGE
16
6.3.
ECOLOGY
16
6.4.
GEOLOGY, HYDROGEOLOGY AND SOILS
17
6.5.
LANDSCAPE AND VISUAL
18
6.6.
NOISE AND VIBRATION
18
6.7.
SOCIO–ECONOMIC
19
6.8.
SURFACE WATERS
20
6.9.
TRAFFIC AND TRANSPORT
21
7.
RESIDUAL IMPACTS
21
8.
CONCLUSION OF THE 2013 UPDATE
22
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1.
INTRODUCTION: HOW AND WHY IS WYLFA APPLYING FOR CONSENT TO
DECOMMISSION?
Wylfa Nuclear Power Station (hereafter Wylfa) will cease electricity generation and commence
decommissioning in the next few years. In order to decommission, Wylfa must obtain consent
from the Health and Safety Executive (HSE). The Office for Nuclear Regulation (ONR) is the
agency of the HSE that deals with decommissioning consents, and both the HSE and ONR are
referred to in this document. To obtain consent to decommission, Wylfa must prepare an
Environmental Statement (ES), with a Non-Technical Summary (NTS) that explains the
decommissioning projects, and states its environmental impacts and the steps Wylfa will take to
mitigate or offset any of these impacts.
It is important to note that Wylfa already has a decommissioning consent in place. However, as
a result of the successful extension of the generating life of Wylfa, this consent will expire before
decommissioning can commence and therefore a new consent is required.
This NTS is based upon the findings of a Environmental Statement 2013 Update document,
(referred to here as the ‘2013 Update’) which updates the previous ES that Wylfa submitted in
support of its existing decommissioning consent.
Figure NTS 1: Document Structure. Red text indicates documentation produced specifically to
support the current application, and black text indicates the original 2008 ES.
All these
documents form the basis of the current application to decommission Wylfa.
1.1. Background to the Application to Decommission Wylfa
In August 2008 Magnox supplied the HSE with an Environmental Statement (referred to here as
the ‘2008 ES’) to support an application to decommission the site. The 2008 ES reported the
findings of an EIA that was carried out to consider the potential environmental effects occurring
as a result of the proposed decommissioning works. It identified the adverse or beneficial
environmental impacts of the decommissioning project and the proposed measures to be taken
to avoid, reduce or offset those adverse impacts. After consideration of the 2008 ES, the HSE
granted consent to decommission Wylfa on the 25th of March 2009.
A condition of the consent was that decommissioning should commence within five years (i.e.
by March 2014). In 2008 it was envisaged that Wylfa would cease electricity generation within
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five years, although it was at the time recognised that there was a case for extending the period
of generation. Since 2008 Magnox has successfully made the case for extending the
generating life of Wylfa to September 2014. Though work is on-going to extend this to
December 2015 assuming the appropriate consents are received.
Under current plans Wylfa will therefore not satisfy the condition to commence decommissioning
within the five year period and as a result the consent will expire.
1.2. Approach to Gaining Consent
After consultation with the ONR, Magnox have decided to adopt the following approach to
gaining a new consent:



Review the original 2008 ES to identify any areas that require modification as a result of
the revised decommissioning date;
Revise and update the 2008 ES as required, by incorporating any required changes
from the above review into (1) a 2013 Update Document and (2) a Non-Technical
Summary (this document); and
Re-apply for consent, by submitting the 2013 Update Document and the original 2008
ES documentation to the ONR.
The review takes full account of proposed new developments in the area, including the
proposed new nuclear power station (which is described in more detail below). These are
reviewed to determine if they create any cumulative environmental impacts, when considered in
combination with the decommissioning proposals at Wylfa.
In addition to the above steps, in November 2012 Magnox asked the ONR (as the appropriate
agency of the HSE), to provide a Pre-Application Opinion (PAO) on the proposed approach
towards gaining consent to decommission Wylfa (in accordance with Regulation 6 of EIADR
99). The output from the PAO is described in the 2013 Update Document.
1.3. Stakeholder Engagement
Stakeholder engagement is a key component in the process of gaining consent to
decommission. It ensures transparency in the project and its impacts, and provides all
stakeholders with an opportunity to comment on, and thereby influence the assessment. The
Stakeholder Engagement carried out for the 2008 ES is described in Section 3 of that
document. This was an extensive and comprehensive engagement, the role and outputs of
which are fully explained in the 2008 ES. For this application, it was concluded that it would not
be appropriate to fully repeat this engagement because:
 The decommissioning plans have not changed significantly;
 Local people would be unlikely to want to comment on the same information and
proposals twice;
 The change to the decommissioning start date is relatively small, and other dates
remain largely unaffected.
Instead, stakeholder engagement for this application was carried out through the Site
Stakeholder Group (SSG), through internal communications and through adverts in the Wylfa
th
th
Information Centre. Presentations were given to the group on 13 September 2012 and 13
December 2012. On-going consultation will be held with the SSG on the progress of the
decommissioning application. The PAO consultation was reported at the SSG and also in the
Wylfa Site weekly team brief, and on the Site’s information boards. The PAO was also
advertised at the entrance to the Wylfa Information Centre, which is open to the public (See
Photograph NTS 1).
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Photograph NTS1: Stakeholder poster at the Wylfa Information Centre
1.4. Method for the 2013 Update
The methods described below were used to determine the on-going validity of the 2008 ES to
provide the basis of a new application to decommission Wylfa. The primary purpose of the
2008 ES is to ensure that appropriate mitigation is in place to protect the environment during
decommissioning. Therefore to establish the on-going validity of the 2008 ES, it was
determined if the revised decommissioning start date:



Results in a revised environmental baseline for the area;
Means that new methods for EIA are available;
Results in any potential change in cumulative impacts as given in the original 2008 ES,
or in any new cumulative impacts or if there were any potential synergies with new
nuclear build or other major surrounding developments;


Results in any new impacts not already assessed in the original 2008 ES; or
Requires any change or additions to the proposed mitigation procedures provided in the
original 2008 ES;
This approach was agreed with Hyder (as independent experts) and the ONR.
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2. THE WYLFA SITE
Wylfa is located on the north coast of the Isle of Anglesey at Wylfa Head, Cemaes Bay (see
Photograph NTS 2 below, and also in the 2008 ES, Supplementary Drawings Figure
WYA/GEN/1). Magnox is the licensee of Wylfa under the Nuclear Installations Act 1965 (as
amended). The UK Government’s Nuclear Decommissioning Authority (NDA) owns the site and
Magnox manages the site under contract to the NDA.
The nuclear licensed site at Wylfa covers approximately 21 hectares and can be considered as
two parts:


The area within the Inner Security Barrier (ISB); and
The conventional area.
Other than these two general areas, outside of the outer security fence are: the jetty, the
information centre, simulator training building, reception centre, contractors car park, the off-site
emergency control centre, emergency equipment storage compounds and the 132 kilovolt (kV)
and 400 kV electricity substations. The Wylfa Learning & Development Centre is located at
Coleg Menai and it is not part of the decommissioning project.
These substations provide the electrical connection to the power station site and are owned by
the National Grid Company. They are located in close proximity to the outer security fence, but
the substations are not part of the decommissioning project.
Photograph NTS2: View of Wylfa Nuclear Power Station and Surrounding Area
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2.1. The Site Surroundings
The environmental impacts of the decommissioning project have been considered in the context
of the existing site surroundings. The existing site surroundings are described in Part One,
Section 4 of the 2008 ES and in the individual technical sections of Part Two. A summary of the
area surrounding Wylfa is presented in Box NTS1 below.
Box NTS1: The Area Surrounding Wylfa
Main access route:
The main vehicular route to and from Wylfa power station site is the A5025 which connects the site
to the A5 at Valley and the A55, approximately 20km to the south. To the east, the A5025
connects the power station to Cemaes Bay and a number of other settlements on the northern and
eastern coast of Anglesey. In both directions this route is predominantly rural in nature but also
runs via a number of settlements.
Landscape features:
Essentially rocky shoreline to the north west. Wylfa Head to the north east, a level outcrop with
craggy shoreline. Area of flat small scale agricultural fields surrounding the site and vegetated area
to the south. Close to the coast the land generally comprises rough grazing with exposed rock and
gorse thickets. Further inland the land comprises gently undulating, low lying farmland and isolated
woodland.
Air Quality:
There are currently no Air Quality Management Areas (AQMAs) on the Isle of Anglesey and none
pending.
Main surface
feature:
water
The main surface water feature in the area with the potential to be directly affected by the site is
the coastal water of the Irish Sea. It is from here that water is abstracted for use on the site prior to
being discharged back to the sea. There are no significant surface fresh water courses at or within
the immediate area to the Wylfa site. There are a number of small springs and drainage ditches
feeding Tre’r Gof SSSI located to the north-east of the station.
Underlying bedrock:
The underlying bedrock is New Harbour Group of the Pre-Cambrian Mona Complex.
Wylfa Head and part of the headland to the north-west of the site comprise rocks of the Gwna
Group. Within the New Harbour Group there are outcrops of extrusive igneous rock, with one such
outcrop cutting across the site to the south of the turbine hall and reactor building. There are no
major aquifers.
Nearest Settlements:
Tregele 1km south-west.
Cemaes 2km south-east.
Amlwch 9km east.
Holyhead (nearest town with over 10,000 inhabitants) 27km south-west.
Designated Sites of Conservation
Designated sites of
nature
conservation
interest:
Tre’r Gof SSSI.
Cemlyn Bay SSSI.
Ynys Feurig, Cemlyn Bay and The Skerries Special Protection Area (SPA).
Cemlyn Bay Special Area of Conservation (SAC).
Designated geological
sites of conservation
value:
There are no designated geological sites of conservation value on or adjacent to the power station.
The nearest is Henborth Site of Special Scientific Interest (designated for its geological features)
which is approximately 2km from Wylfa.
Archaeology and Cultural Heritage
Scheduled Monuments:
Listed Buildings:
Historic
Parks
Gardens:
Historic Battlefields:
and
There are no Scheduled Ancient Monuments on the power station site. The nearest Scheduled
Ancient Monument is a triangular arrangement of Early Bronze age standing stones 2.5km southwest of the site.
There are no Listed Buildings within the study area. There are three Listed Buildings 1km southwest of the power station.
Cestyll Gardens lies within the NDA landholding and is included in the Register of Landscapes,
Parks and Gardens of Special Historic Interest in Wales.
There are no registered historic battlefields within the study area.
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3. THE DECOMMISSIONING PROJECT
The decommissioning project is described in Section 6 of the 2008 ES. This comprises three
main stages. Over a period of about 10 years all the machinery and buildings except the
reactor building will be dismantled and removed. During this time, referred to as ‘Care and
Maintenance Preparations’, the reactor building will be prepared for an extended period of
safe storage, known as ‘Care and Maintenance’, until the radioactivity levels inside the
reactors will be low enough to simplify their final dismantling. This period of storage ends
approximately 85 years after the end of the Care & Maintenance Preparations phase. Following
the Care and Maintenance period, over about 8 years, the reactors and the reactor building will
be removed and the site finally cleared; this is known as ‘Final Site Clearance’.
Box NTS 2 provides a summary of the three main decommissioning stages.
Further
information on the decommissioning and waste management strategies, in particular in relation
to Government policies, can be found in Part One, Section 5 of the 2008 ES. Reasons for the
selection of strategies for the various aspects of the proposals can be found in Part One,
Section 7 of the 2008 ES.
Box NTS 2: Summary of the Main Stages of Decommissioning



Care and Maintenance Preparations is the first stage and is estimated to take approximately 10
years to complete. During this stage all of the radioactive and non-radioactive plant and buildings
on the site other than the reactor building (and most of its contents) will be dismantled and cleared.
The Reactor buildings will be clad and ‘safestored’ – which means that they will be prepared for the
next stage of decommissioning. A radioactive waste storage facility will be built to house some
waste. Some lower activity radioactive wastes will leave the site for disposal or recycling.
Care and Maintenance is the second stage which, it is proposed, will last for a number of decades,
during which no significant dismantling will be carried out. During this time the site will continue to
be managed, monitored and maintained in a safe state. The radioactive waste store will be
emptied and demolished during this period, as soon as practicable after a national waste repository
is available. Photograph NTS3 shows an artist’s impression of Wylfa during this time.
Final Site Clearance is the last stage and is expected to take about 8 years. This involves the
dismantling of the remaining structures on the site, including the reactors, and the clearance of any
residual radioactivity to the applicable standards.
Photograph NTS 3: An artist’s impression of the reactor building and radioactive waste
storage building during Care and Maintenance
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3.1. How Will the Work be Managed?
Information on the management of the site and work during all phases of decommissioning can
be found in Part One, Section 6 of the 2008 ES.
Hours of Work
Typical normal working hours during decommissioning will involve staff working a 37 hour week,
starting and finishing between the hours of 07:30 and 17:30, Monday to Friday. Working hours
may alter for certain activities; for example, from time to time the working day may be extended
in order to complete specific items of work safely, and some night-time working may be required
to accommodate certain activities such as concrete pouring. Seven days a week, 24 hours a
day shift working may be necessary for retrieval of some radioactive wastes and for subsequent
waste packaging operations, but these operations will take place within buildings only.
Numbers of Workers
The current power station workforce currently comprises of 589 permanent staff and around 100
subcontractors 1 . Numbers of workers will fluctuate over the project but the maximum number of
workers on site will be about 600 during Care and Maintenance Preparations, with no
permanent presence expected for the majority of Care and Maintenance (with the exception of
routine maintenance and security personnel) and a maximum of 450 workers in Final Site
Clearance.
HGV Movements
There is likely to be a temporary increase in the number of HGV movements to and from the site
as a result of the proposed Care and Maintenance Preparations activities. Excluding the
continued routine deliveries of consumables, peak HGV movements associated with this phase
are estimated to reach no more than 35 or so vehicles travelling to and away from the site on a
week day. The movement of HGVs over weekends is expected to be very limited.
During Care and Maintenance there will be very little traffic travelling to and from Wylfa. The
only regular traffic movements will relate to security or inspections personnel, with visits for
maintenance purposes as and when required. There will be a need to remove the contents of
the radioactive waste store, and demolish the building, but traffic movements associated with
this are not considered significant (and will be well below current the levels of traffic generated
by Wylfa). Again excluding routine deliveries of consumables, HGVs movements associated
with Wylfa during Final Site Clearance are estimated to reach an average of 50 vehicles
travelling to and from the site on a week day. Once the Final Site Clearance phase is complete,
there will be no traffic travelling to or from Wylfa power station.
Land Use
Almost all of the works will be carried out within the current outer site fence. The main exception
to this is the work associated with the jetty, offshore seawater intake structures and cooling
water (CW) outfall complex. Suitable notices to mariners will be issued via the Admiralty
highlighting any navigational issues, including the loss of the navigation lights currently on the
structures. Any vessels involved in offshore work will be marked and appropriately lit as agreed
with the relevant bodies.
Radioactive Discharges
During decommissioning, radioactive discharges to air and to the sea from Wylfa will continue. It
is expected that gaseous and liquid discharges will be reduced compared with when the station
1
There has been a small reduction in staff numbers at Wylfa since the 2008 ES was published.
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was operational. However, there may be peaks resulting from certain activities. All discharges
will be made in accordance with authorisations granted by the Environment Agency (EA) under
the provisions of the Environmental Permitting Regulations 2010. A summarised description of
the discharges expected to arise during decommissioning is given in Box NTS 3.
Where necessary, buildings and work areas with the potential for airborne radioactive
contamination will have forced ventilation with exhaust air passing through filters as appropriate.
The radioactive waste storage building will be ventilated by passive means - air in this building
is expected to contain only traces of tritium (the radioactive form of hydrogen). Discharges,
aerial or liquid, will be monitored and reported to the Environment Agency as required under the
terms of the discharge authorisation.
Box NTS 3: Radioactive Discharges
Care and Maintenance Preparations
 The main sources of radioactive gaseous discharges will be from the reactor vessels which had
held the fuel in the reactors and from the ventilation of contaminated areas.
 Radioactive liquid effluent arisings will result from wet cutting operations, decontamination
operations, the use of showers and the operation of laundries. All waste water arising on site that
has the potential to be radioactively contaminated will be treated to minimise its radioactive content
before being discharged to the Irish Sea.
Care and Maintenance
 There will be a small gaseous discharge of radioactivity from the reactor vessels and there will also
be traces of tritium being released to the atmosphere from the radioactive waste storage building.
Overall the atmospheric discharges from the site will be much smaller than when the reactors were
operational, much lower than during Care and Maintenance Preparations and much lower than the
current authorised limits.
 Under normal circumstances no liquid radioactive discharges are expected.
Final Site Clearance
 Radioactive airborne emissions will result mainly from cutting processes to dismantle the reactor.
 Radioactive liquid wastes will result from water drenching of cutting activities.
Further information on radioactive discharges from Wylfa can be found in Part One, Section 8 of
the 2008 ES.
Safety
As now, the safety of the public and the workforce will be a priority during decommissioning.
Safety, both nuclear and conventional, will be regulated by the HSE in consultation with the EA.
Wylfa will continue to be licensed under the Nuclear Installations Act (1965, amended) and
therefore will still require a Safety Case, this being a document or set of documents that
provides for the safe operation of plant and equipment or the carrying out of certain activities.
As the decommissioning of Wylfa continues, the Safety Case will be updated progressively.
Further information on the safety case system, as well as emergency arrangements, can be
found in Part One, Section 8 of the 2008 ES.
Security
Security arrangements that comply with Government requirements are in force at Wylfa. These
are kept under review by Magnox and its regulators to ensure their continuing effectiveness. As
the detailed security arrangements at civil nuclear sites are a sensitive matter, in accordance
with Government policy details are not included in this submission.
Security at Wylfa will remain on shift 24 hours per day, seven days per week during Care and
Maintenance Preparations and Final Site Clearance. For the Care and Maintenance phase all
the buildings remaining on the Wylfa site will be designed to be resistant to unauthorised entry
and will have intruder detection systems. Full time on-site security personnel may therefore not
be required during this phase, subject to gaining appropriate approval.
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3.2. Change in Decommissioning Strategy since 2008
There has been no change to the overall strategy for decommissioning Wylfa since the original
ES was produced in 2008. In terms of the approach to decommissioning, since 2008 Magnox
has identified that an alternative package design is the best approach for storing some forms of
radioactive waste and has adopted the Magnox Optimised Decommissioning Programme
(MODP) in order to coordinate a consistent programme of decommissioning across sites which
prioritises high hazard reduction. However these changes do not affect the overall strategy that
formed the basis of the original ES in 2008. A summary of changes is presented in Appendix 1
of the 2013 Update document.
4. WHAT DEVELOPMENT PROJECTS IN THE WYLFA AREA COULD AFFECT OUR
PLANS?
It is important that an EIA takes full account of any surrounding developments that could create
cumulative environmental impacts, or which could impact upon the effectiveness of mitigation
put in place to protect the environment. This is particularly relevant given the long timescales
associated with decommissioning Wylfa, and was identified in the PAO response.
Since the 2008 ES was prepared, a number of significant infrastructure projects have been
identified as being potentially located in Anglesey. By far the most significant proposal for the
area around Wylfa is the proposed construction of a new nuclear power station.
4.1. Nuclear New-Build
Horizon Nuclear Power is now proposing to construct a new nuclear power station in the area
immediately adjacent to the Wylfa site. Transfer of land from Wylfa (and other surrounding
properties) to Horizon has taken place.
In October 2012 Horizon’s shareholders – (E.ON UK and RWE npower) announced that
agreement had been reached to sell Horizon to Hitachi. The sale of Horizon means that the
details of the new nuclear power station will be different from those previously released by
Horizon, because Hitachi are proposing to build Advanced Boiling Water Reactors (ABWR),
which were not previously considered. Hitachi must achieve licence acceptance for the ABWR
under the ONR’s Generic Design Assessment process. This means that immediate physical
works at Wylfa are not likely to occur in the very near future, though this remains uncertain at
this point, and Hitachi have indicated their desire to have an operational site in the UK (land at
Oldbury in Gloucestershire is also owned by Horizon) by the first half of the 2020s.
It is likely (though again not certain) that the output from the proposed new nuclear power
station would be connected to the National Grid via the existing 400kV substation (which is
adjacent to the Wylfa site) however an extension to the existing sub-station may be required as
well as additional transmission infrastructure (given the much higher power output that the new
station will produce). It is understood by Magnox that an application for development consent
and supporting ES will be brought forward by National Grid Electricity Transmission PLC, which
will set out the full details of the required alterations, and associated their potential
environmental impacts.
4.2. Other Infrastructure projects in Anglesey
A number of significant infrastructure projects on Anglesey are now proposed that had not been
initiated at the time of the 2008 ES. No direct account of their impact on Wylfa’s
decommissioning plans can be undertaken at this stage, because the relevant plans are not
sufficiently mature, with one exception which is detailed below. However they could ultimately
affect Wylfa’s decommissioning plans or mitigation (e.g. through the potential for cumulative
environmental impacts).
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A major initiative in the area is the Anglesey Energy Island Programme (EIP), which is a
collective effort between several stakeholders (including Wylfa) within the public and private
sector working in partnership to put Anglesey at the forefront of energy research and
development, production and servicing, bringing with it potentially significant economic
investment. Wylfa fully supports the EIP and close working will be maintained to ensure that
relevant developments are taken into account during the decommissioning project. The
proposed developments currently identified as part of this programme are as follows; it should
be noted that none of these proposals have received formal planning permission at the time of
writing:




A large offshore wind power development (Rhiannon Wind Farm) in the Irish Sea to the
north of Anglesey, proposed by a joint venture collaboration of Centrica and Dong
Energy (‘Celtic Array’);
A biomass-burning combined heat and power plant at the site of the former Anglesey
Aluminium plant, proposed by Lateral Power; and
A marine tidal turbine array between Carmel Head and The Skerries, proposed by
Marine Current Turbines.
Planning permission for a Liquid Natural Gas plant at Amlwch was approved in March
2008, and the planning application is expected to be renewed because the original
permission will expire on 28/03/13. In 2008 an ES was submitted for this project and it
is understood that an updated ES will be submitted to support a renewed application.
This will be reviewed by Wylfa when it is available.
In addition to these potential developments there is a series of infrastructure and other
supporting proposals that would act in conjunction with the above list:



An upgrade of the high-voltage power lines within and leading off Anglesey by National
Grid, to support the large output of the proposed developments;
An accommodation development in Holyhead proposed by Land and Lakes for
construction workers as part of the Horizon Nuclear Power project (to be reused as a
holiday destination after completion the construction project);
An upgrade to the Port of Holyhead, being developed by Stena Line, with a view in part
to take advantage of the Celtic Array development.
With the exception of the Marine Current Turbines none of the major infrastructure projects are
sufficiently mature for their impacts to be taken directly into account at this time. Marine Current
Turbines proposals have been reviewed, and it has been concluded that there is no potential for
any cumulative impacts, though this, and all other development-related impacts, will be kept
under review.
5. THE ROLE OF THE ENVIRONMENTAL MANAGEMENT PLAN (EMP)
As explained above, Wylfa currently has consent to decommission (though as described above
this will expire before decommissioning can commence at Wylfa). A condition of the existing
consent is that Wylfa produces an Environmental Management Plan (EMP) 2 . The EMP
describes the mitigation measures that Wylfa will use to prevent, reduce and where possible
offset any significant adverse effects on the environment caused by decommissioning Wylfa.
The EMP is re-issued annually and submitted to the HSE / ONR and the EMP is also available
to stakeholders and the public, and at other Magnox sites the ONR has audited performance
against the EMP 3 . The EMP will also be used to record any changes that we need to make to
our mitigation proposals (as agreed with the ONR and other regulators) during the course of the
2
Wylfa Site Environmental Management Plan Issue 3 June 2012
Site-specific ‘intervention reports’ are produced by the ONR after these audits, which can be found here:
http://www.hse.gov.uk/nuclear/intervention-reports/index.htm
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3
decommissioning project, including any required to offset any cumulative impacts caused by the
proposed new nuclear power station at Wylfa. The EMP also reports on the effectiveness of
the mitigations we have employed.
6. THE ENVIRONMENTAL IMPACT ASSESSMENT
The Environmental Impact Assessment (EIA) process identifies the potentially significant
environmental effects associated with a project, e.g. decommissioning, and allows them to be
taken into account in the decision making process. The topic areas that were considered in the
assessment are considered individually below.
6.1. AIR QUALITY AND DUST
The matters considered under Air quality and Dust were: emissions of gaseous pollutants and
particulates from vehicles; the raising and dispersion of dust from the site directly due to the site
works; and the dispersion of dust from soiled vehicles or vehicles carrying potentially dusty
loads off site.
The approach and mitigation measures identified in the 2008 ES are considered to remain valid.
Following consultation with Isle of Anglesey County Council’s Environmental Health Officer,
more prescriptive measures for monitoring Air Quality and Dust have been identified.
6.2. ARCHAEOLOGY AND CULTURAL HERITAGE
None of the archaeological or historical features identified in the 2008 ES as being in the locality
of Wylfa will be physically affected by the proposed decommissioning project. There is no
evidence of any surviving features of archaeological interest within the licensed power station
site that will be physically affected by the decommissioning project. The initial construction of
the power station, particularly the deep foundations and basements of the turbine hall and
reactor building, would have already affected (and probably destroyed) any below ground
remains. The potential for any further remains on the site is negligible.
The construction of Wylfa, with its deep excavations, is likely to have removed all traces of
structural evidence for past use for the headland within the footprint Wylfa. It is not anticipated
that any further ground-intrusive works resulting in the disturbance of the burial environment of
the Wylfa footprint is to take place. There would therefore be No Change on the buried
archaeological resource.
In view of the industrial significance of the Wylfa complex, it will be recorded at an appropriate
level before dismantling works are undertaken and records relating to its construction and use
will be deposited in an appropriate archive.
6.3. ECOLOGY
The matters considered under this topic were:

Habitat loss including the removal of on-site structures potentially used by bats
and/or protected bird species;

The effects of the removal of off-shore structures on birds and marine flora and
fauna, including habitat loss and disturbance due to the work;

The effects of noise, vibration and visual disturbance on fauna, particularly on birds
using the foreshore;

Potential changes in incidental mortality of birds, amphibians, reptiles and/or other
protected species as a result of site works or of changes in vehicle movements;

Possible effects of dust on sensitive habitats;
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
Potential effects of accidental spills or pollution on nearby water bodies and
watercourses where there is a pollutant pathway from the site; and

Potential effects, similar to those listed above, upon sites designated for their nature
conservation importance that are remote from the site.
The effects of the permanent loss of warm water discharges on marine flora and fauna (though
strictly an effect of end of generation rather than of decommissioning as such) were also
included in the assessment.
Since the 2008 ES was prepared, it has been confirmed that a pair of choughs, a specially
protected bird species that is listed on Schedule 1 of the Wildlife and Countryside Act 1981,
have nested at Wylfa.
The impacts outlined within the 2008 ES are considered to remain valid, but in addition to those
impacts, it is predicted that a ‘moderate adverse’ impact on breeding choughs (a receptor of
‘regional importance’) would occur as a result of loss of nesting sites and noise and visual
disturbance.
The mitigation measures described in the 2008 ES for offsetting the predicted effects remain
valid. In addition to those measures, mitigation for the loss of chough nest sites will be provided.
This will include the provision of artificial nest boxes within an area that would not be disturbed
by the proposed works. Suitable nest boxes will be provided prior to the commencement of the
decommissioning works that could affect choughs. In addition, the demolition of any buildings
that are used by nesting choughs will be undertaken outside of the bird breeding season (which
is between the months of March and August (inclusive)).
Updated surveys for badgers, otters, water voles, bats and other legally protected species will
be undertaken one year before the commencement of any works that could affect these
species. As a precautionary measure, the mitigation described in the 2008 ES to prevent the
incidental mortality of adders will be extended to include all suitable reptile habitat within the
site. This will include a targeted reptile survey one year prior to the commencement of the
decommissioning works and hand-strimming any suitable vegetation that is present within the
site that would be directly affected by the proposed works. If reptiles were found to be present
during the pre-decommissioning survey, reptile-proof fencing will be installed around such
areas.
The implementation of measures that would provide a net gain for biodiversity will be discussed
and agreed with the Countryside Council for Wales (which will become Natural Resources
Wales in April 2013) prior to the commencement of decommissioning works
6.4. GEOLOGY, HYDROGEOLOGY AND SOILS
The matters considered under this topic were:

The consequences of any remediation of contaminated ground and/or groundwater,
both while carrying out the works and subsequently;

Inadvertent or uncontrolled disturbance or spreading of existing contaminated soils,
including movement by windblown dust, entrainment in rainfall runoff, attachment to
vehicles and/or inappropriate soil handling operations;

Compaction of soil due to vehicular movements and degradation of soil quality due
to construction activities and lay down areas;

Mobilisation of existing contamination by direct rainwater infiltration due to changes
in ground cover or the creation of temporary open excavations;

Mobilisation of existing contamination due to changes in water table levels and
consequential changes to the groundwater flow regime (e.g. due to changes in
ground covering and rainwater infiltration);
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
Creation of new contaminant migration pathways (e.g. due to the creation of
boreholes, piles or excavations connecting previously unconnected geological
strata);

Inadvertent contamination of soils and/or groundwater arising from temporary
storage of contaminated soils, wastes or materials;

Inadvertent contamination of soils and/or groundwater arising from inappropriate use
of contaminated soils, wastes or material as infill material;

Inadvertent effects on groundwater flow and quality due to infilling of deep
basements and the breaching of basement structures to prevent ponding;

Spills or leaks of radioactive and non-radioactive substances; and

Inadvertent effects of local dewatering on groundwater resources and nearby
abstractions, watercourses and sites of conservation interest.
In addition, consideration has been given to changes in the groundwater regime potentially
leading to:

Changes to the risk of groundwater-induced flooding (on or off site); and

Changes to the risk of groundwater-induced building damage (on or off site).
It is predicted that potential adverse impacts will arise during the Care & Maintenance
Preparations phase and/or the Final Site Clearance phases. Following a precautionary
approach, most of the adverse impacts were considered to be potentially significant or key
significant. Therefore, mitigation measures have been proposed following best practice and/or
all applicable British Standards (BS) or EA Pollution Prevention Guidance Notes. With these in
place none of the residual impacts are predicted to be significant.
The 2013 Update has highlighted additional impacts and mitigation that will need to be out in
place during decommissioning (following updated guidance) including the production of a
Qualitative Risk Assessment for and quality, and a specific review to establish the impacts of
dewatering activities.
6.5. LANDSCAPE AND VISUAL
The landscape and visual impact assessment addresses impacts on the landscape resource
(e.g. loss of trees, changes to landform etc.), impacts on views (e.g. changes to scenic
composition) and the consequent changes to landscape character.
The methodology in the 2008 ES remains current, although it is recognised that the Guidelines
for Landscape and Visual Impact Assessment 2002 2nd edition is presently being reviewed and
updated. The date for the publication of the 3rd edition is not currently known.
It is not anticipated this or the new baseline data identified above will require any changes to the
mitigation in the 2008 ES.
A seascape assessment will be carried out once further information on the proposed new
nuclear power station at Wylfa becomes available. The methodology will be agreed with
Countryside Council for Wales and Isle of Anglesey County Council.
6.6. NOISE AND VIBRATION
The noise and vibration assessment has taken into account noise and vibration deriving directly
from the Wylfa site, as well as that due to site traffic (including the use of Heavy Goods Vehicles
(HGVs)). The traffic data used in the assessment took into account predictions of future
changes in background traffic.
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As agreed with Isle of Anglesey County Council, a revised noise impact assessment is not
considered necessary at this stage and cumulative noise impacts will be presented as part of a
‘Section 61 Consent Application’ (under the Control of Pollution Act 1974) which will be made
directly with Isle of Anglesey County Council. The Section 61 agreement is a formal agreement
between the Wylfa and the Isle of Anglesey County Council where noise levels, hours of work
and any mitigation are agreed upon.
Until such time that detailed working methods are defined, it is not possible to determine the
noise level reduction that would be gained through the use of mitigation. However, mitigation
will reduce noise levels and, depending on the level of reduction, will also potentially reduce the
significance of noise impacts.
The Section 61 Consent Application will provide for a more robust assessment of the noise
impacts and the identification of more specific mitigation measures to reduce noise impacts. It
will ensure that the most appropriate mitigation is implemented for the proposed works to be
carried out. The mitigation will need to be specific and demonstrate to Isle of Anglesey County
Council that agreed noise limits will be met.
The predicted noise impacts for the Section 61 Consent Application would require the appointed
contractor(s) to prepare definitive method statements to allow an accurate prediction of noise
impacts and design of appropriate mitigation measures.
6.7. SOCIO–ECONOMIC
The main impacts considered under this topic were:

Changes in direct and indirect employment supported by the power station, including
the scope for retraining and reskilling of the existing power station workforce to
enable their employment in the decommissioning works;

Effects on employment and unemployment levels in the local economy, and
changes in the structure of local employment;

Changes in local expenditure by power station employees, Magnox and its
contractors;

Immigration and emigration of power station employees and contractors and
resulting changes in local population levels and structure;

Changes in the demand for temporary accommodation;

Changes in the demand for permanent housing and effects on the local housing
market;

Changes in pupil numbers in local schools; and

Changes in the demand for community/amenity facilities and services.
Other impacts which have been considered in the assessment, but in less detail, include:

Changes in commuting patterns;

Effects on key local economic sectors (e.g. tourism, agriculture, fisheries);

Changes in the development potential of the area; and

Changes in the incidence of social problems including crime and disorder.
It is considered that mitigation measures referenced in the 2008 ES remain valid.
Given that details of the timing and composition of the workforce for the proposed new nuclear
power station at Wylfa are currently unknown, quantifying and determining the significance of
the combined effects of Wylfa and the proposed new nuclear power station is not practical at
this time.
Wylfa Power Station
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However, it is possible at this time to state the possible mitigation measures which could be
employed in relation to nuclear new-build:

Magnox will make every effort to re-deploy affected staff and support staff in retraining or re-skilling for decommissioning roles, in addition to retraining for new roles
within the proposed new nuclear power station at Wylfa (if feasible) and other
industries on Anglesey;

Preparing a joint Traffic Management Plan with the owners of the proposed new
nuclear power station at Wylfa (i.e. minimise effects on the Island’s tourism sector);

Potentially inputting into a Welsh Language Impact Assessment prepared by the
owners of the proposed new nuclear power station at Wylfa; and

The co-ordination and joint working between Magnox and other developers on
Anglesey (including the owners of the proposed new nuclear power station at Wylfa)
would be pursued where socio-economic gains could be secured.
6.8. SURFACE WATERS
The surface waters assessment primarily addressed:

The removal of off shore structures;

Impacts on surface water quality from changes in the non-radioactive content of
routine discharges from the site;

Changes in the non-radioactive content of routine discharges of operational effluents
associated with decommissioning;

The potential release of turbid and/or contaminated water (e.g. via storm drains) due
to decommissioning activities on site;

Changes in the risk of on- or off-site flooding as a result of decommissioning (e.g.
Due to changes made to storm drains, construction of new buildings or
hardstandings or removal of existing buildings or hardstandings);

Impacts to water quality in bathing areas;

Changes to the site’s runoff characteristics;

The non-radioactive content of discharges of operational effluents authorised under
the environmental permitting regulations 2010;

Radioactive discharges;

Sediments released due to movements of HGVs and heavy plant;

Changes to coastal erosion processes caused by the cessation of cooling water
discharges;

Flood risk; and

Impacts relating to potential spills and leaks of radioactive and non-radioactive
substances to nearby waterbodies.
Updates to baseline data have been assessed, but the new data corroborates the 2008 ES
assessment of the sensitivity of the water environment within the study area. As a result there is
no requirement for revision of the magnitude or overall significance of the predicted impacts. No
new impacts are anticipated as a result of the revised timeline.
The proposed mitigation
measures outlined in the 2008 ES are considered still relevant and appropriate in line with
current best practice.
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6.9. TRAFFIC AND TRANSPORT
The traffic and transport assessment considered the impact of traffic associated with the
decommissioning project at Wylfa on the operation of the highways, road safety and the local
‘environment’, including the experience of or difficulties encountered by other road users and
pedestrians (excluding the noise/vibration and emissions effects of traffic which were
considered separately under the topics of noise and vibration and air quality respectively).
The traffic impacts were assessed through consideration of the percentage changes in total
vehicle numbers and, separately, in HGV numbers. Other factors considered included the
operational capacity of the roads, recent accident records, the presence of vulnerable road
users and of residential properties, schools, hospitals etc. Predictions of future background
traffic growth were taken into account.
The percentage changes in total traffic and HGVs using the data from the updated 2011
surveys show the impacts to be either similar or lower than the impacts presented in the 2008
ES when using the 2007 survey data. However, to reduce the traffic and transport impacts
associated with the decommissioning of Wylfa, a Traffic Management Plan will be prepared and
agreed with the Highway Authority for the Care and Maintenance Preparations and Final Site
Clearance phases. The traffic and HGV generations during the Care and Maintenance phase
are relatively low and whilst Travel Plan measures, such as car sharing, will be encouraged, no
specific measures are proposed for this phase.
7. RESIDUAL IMPACTS
With mitigation measures in place the only key significant adverse environmental impacts
identified as a result of the assessment were:

Visual impact on two Area of Outstanding Natural Beauty (AONB) views as a result
of dismantling works and recladding and modification works to the reactor building
during Care and Maintenance Preparations and demolition works during Final Site
Clearance.
With mitigation measures in place the only significant adverse environmental impacts identified
as a result of the assessment were:




Visual impacts on local and middle distance views and one open access land view
as a result of views of decommissioning works during Care and Maintenance
Preparations and Final Site Clearance, with corresponding significant adverse
impacts on landscape character;
Potential worst case noise impacts at nearby residential properties during Care and
Maintenance Preparations and Final Site Clearance (dependent on working
methods and the effectiveness of mitigation);
The permanent long term loss of employment opportunities in the sub area
containing the site, known as Anglesey North, that will occur by the end of the Care
and Maintenance Preparations, with associated short term impacts on the levels of
unemployment; and
Possible impact to local road network due to increase in traffic flows. (With a Traffic
Plan proposed as mitigation it is not possible to identify the residual impact
following its implementation and therefore at worst the residual impact could be
‘significant’).
The significant benefits identified were:


Overwhelmingly beneficial visual impacts to local and middle distance views
throughout the area with corresponding benefits to landscape character;
The generation of employment for the immediate cluster of wards for almost a
decade during Final Site Clearance;
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


Impacts on surface water quality due to the end of all site discharges and the
complete removal of the need for any discharge consents from the site;
Impacts on soil and groundwater quality from the completion of any remediation of
contaminated ground during care and maintenance preparations; and
Following final site clearance there will be no traffic travelling to Wylfa which will be
positive in terms of the operation and safety of roads.
As a result of decommissioning the following key significant benefits were identified:


Impacts on soil and groundwater quality from the completion of the remediation of
contaminated ground on the basis that all restrictions including monitoring,
reporting and regulation would cease, and no further remediation would
foreseeably be required; and
Views of the site from sensitive viewpoints such as the Isle of Anglesey Area of
Outstanding Natural Beauty, following the phased removal of the very substantial
mass of the buildings and cessation of station lighting at night.
It is considered that the project to decommission Wylfa Power Station is unlikely to have any
key significant or significant effects on the environment in another European State.
8. CONCLUSION OF THE 2013 UPDATE
This 2013 Update identified the need for further surveys, to be appropriately timed during
decommissioning, and the need for additional mitigation (or mitigation that is specified in a
greater level of detail). These changes have been brought about by changes in legislation and/
or accepted industry best practice. The review has also highlighted mitigation that will require
further engagement from regulators, such as the ‘Section 61’ agreement specified to agree
noise measurement and mitigation.
The impact of new developments around Wylfa, in particular the proposed new nuclear power
station, will need to be assessed as details become available. The mechanism of the EMP will
be used to ensure that future surveys, mitigation requirements and revisions (as required by
new developments), are reported to the ONR and stakeholders.
Continued engagement with regulators and stakeholders will be an important component of the
decommissioning project at Wylfa. As the details of surrounding developments become
available, Wylfa will assess likely cumulative impacts and, in combination with regulators and
stakeholders, will agree and implement appropriate any required additional mitigation measures
to protect the environmental and socio-economic assets of the Isle of Anglesey.
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How Do I Comment on this Document?
If you wish make any comment on this document you should do so in writing to the address
below:
Wylfa EIADR Project Officer
ONR – EIADR Team
4N.1 Redgrave Court
Merton Road,
Bootle
L20 7HS
Availability of Environmental Statements
Copies of the all the documents that comprise the Environmental Statement can be obtained
from:
Document Centre
Wylfa Power Station
Cemaes Bay
Isle of Anglesey
LL67 0DH
The cost of hard copies of these documents is £50. Alternatively, electronic copies are available
on CD free of charge from the address above.
Copies of the non-technical summary are also available free of charge from the address above
or can be viewed on the Magnox Ltd website www.magnoxsites.co.uk.
Where Can I View the Environmental Statement?
Copies can be viewed free of charge at the following locations:
Public Libraries
Amlwch Library
Lôn Parys
Amlwch
LL68 9EA
Tel (01407) 830145
Beaumaris Library
David Hughes Community Centre
Beaumaris
LL58 8AL
Tel (01248) 810659
Bangor Public Library
Ffordd Gwynedd
Bangor
Gwynedd
LL57 1DR
Tel (01248) 353479
Cemaes Library
Glascoed Road
Cemaes Bay
LL67 0HN
Tel (01407) 711025
Holyhead Library
Newry Fields
Holyhead
LL65 1LA
Tel (01407) 762917
Llangefni Library
Lôn y Felin
Llangefni
LL77 7RT
Tel (01248) 752095
Menai Bridge Library
Wood Street
Menai Bridge
LL59 5AS
Tel (01248) 712706
Moelfre Library
Y Ganolfan
Moelfre
LL72 8HA
Tel (01248) 410331
Caernarfon Library
Pavilion Road
Caernarfon
LL55 1AS
Tel (01286) 679463
Rhosneigr Library
High Street
Rhosneigr
LL64 5UX
Tel (01407) 811293
Wylfa Power Station
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