ONR - Office for Nuclear Regulation - The decision on the … · 2018-11-14 · This document reports on the Office for Nuclear Regulation’s decision to grant consent for a decommissioning

The decision on the application to carry out a decommissioning project at Wylfa

nuclear power station under the Nuclear Reactors (Environmental Impact Assessment

for Decommissioning) Regulations 1999 (as amended)

A report prepared by the Office for Nuclear Regulation

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© Crown copyright This publication may be freely reproduced, except for advertising,

endorsement or commercial purposes. First published November 2013. Please acknowledge

the source as the Office for Nuclear Regulation.

Published by the Office for Nuclear Regulation

October 2013

Further copies are available from:

Office for Nuclear Regulation

EIADR Team

Redgrave Court

Merton Road

Bootle

Merseyside

L20 7HS

E-mail: [email protected]

Available on the internet from:

www.hse.gov.uk/nuclear/

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www.hse.gov.uk/nuclear

Contents Page

FOREWORD .................................................................................................... 9

EXECUTIVE SUMMARY ............................................................................... 10

INTRODUCTION............................................................................................ 12

Application for consent to carry out a decommissioning project........... 13

Organisations involved in the consultation process ............................... 15

Request for evidence to verify information within the environmental

statement ...................................................................................................... 15

Review of the Environmental Statement ................................................... 16

Introduction .................................................................................................. 16

Changes in Decommissioning Strategy since 2008 ................................. 16

Review of the environmental impact of the decommissioning project .. 16

Air quality and climatic factors ................................................................... 18

ONR Review.................................................................................................. 18

Consultation Comments.............................................................................. 18

Conclusion.................................................................................................... 19

Archaeology and cultural heritage ............................................................. 20

ONR Review.................................................................................................. 20


Conclusion.................................................................................................... 21

Ecology ......................................................................................................... 22

ONR Review.................................................................................................. 22


Conclusion.................................................................................................... 25

Geology, hydrogeology and soils .............................................................. 26

ONR Review.................................................................................................. 26

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Conclusion.................................................................................................... 27

Landscape and visual .................................................................................. 28

ONR Review.................................................................................................. 28


Conclusion.................................................................................................... 29

Noise and vibration ...................................................................................... 30

ONR Review.................................................................................................. 30


Conclusion.................................................................................................... 31

Socio - economic ......................................................................................... 32

ONR Review.................................................................................................. 32


Conclusion.................................................................................................... 35

Surface water quality, drainage & discharges .......................................... 36

ONR Review.................................................................................................. 36


Conclusion.................................................................................................... 38

Traffic and transport .................................................................................... 39

ONR Review.................................................................................................. 39


Conclusion.................................................................................................... 41

Cumulative Impacts ..................................................................................... 42


Conclusion.................................................................................................... 44

Residual impacts.......................................................................................... 45

ONR Review.................................................................................................. 45

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Conclusion.................................................................................................... 46

Legislation Update ....................................................................................... 47

Effects on other European Economic States ............................................ 47

Conclusion.................................................................................................... 48

Legislative framework for nuclear safety .................................................. 50

Nuclear Installations Act 1965 .................................................................... 50

Other legislation dealing with nuclear and radiological hazards ............ 50

Effects of decommissioning on other countries....................................... 51

Regulators and others working together ................................................... 51

Legislative process under EIADR .............................................................. 51

Application for consent to carry out a decommissioning project........... 51

Public consultation on an environmental statement ................................ 52

Public consultation on further information ............................................... 53

Evidence to verify information in the environmental statement ............. 53

Change or extension to a decommissioning project................................ 53

Granting consent and attaching conditions .............................................. 53

Transparency of ONR’s decision on an application ................................. 53

Annex 2 ......................................................................................................... 55

Consultation on the environmental statement .......................................... 55

Statutory Consultation Bodies ................................................................... 55

Non-Statutory Consultation Bodies ........................................................... 55

Annex 3 ......................................................................................................... 58

Consultees who responded on the environmental statement ................. 58

Annex 4 ......................................................................................................... 59

Summary of environmental benefits and detriments and mitigation measures ...................................................................................................... 59

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Annex 5 ......................................................................................................... 69

Reasons for topics not pursued for evidence or further information ..... 69

Topics not pursued for evidence or further information – topics raised

Issues covered elsewhere – health, safety and environment legislation75

Light pollution .............................................................................................. 73

Removal/demolition of offshore structures............................................... 73

Socio economic............................................................................................ 74

by consultees (2008 & 2013ES) .................................................................. 74

Issues covered elsewhere – town and country planning......................... 75

Issues covered elsewhere – decommissioning timetables: The relationship of government policy, decommissioning strategy and

European initiatives to EIADR and the Wylfa environmental statement 76

Government policy ...................................................................................... 76

Decommissioning strategy review ............................................................. 76

European Commission initiatives .............................................................. 77

Annex 6 ......................................................................................................... 78

Decommissioning Project Consent............................................................ 78

CONSENT...................................................................................................... 78

Conditions attached to Decommissioning Project Consent.................... 80

Condition 1 ................................................................................................... 80

Condition 2 ................................................................................................... 80

Condition 3 ................................................................................................... 80

Condition 4 ................................................................................................... 81

Condition 6 ................................................................................................... 81

Reasons for the conditions ......................................................................... 83

Condition 1 ................................................................................................... 83

Condition 2 ................................................................................................... 83

Condition 3 ................................................................................................... 83

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Condition 4 ................................................................................................... 84

Condition 5 ................................................................................................... 84

Condition 6 ................................................................................................... 85

References .................................................................................................... 86

Glossary of terms and abbreviations......................................................... 88

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FOREWORD

This document reports on the Office for Nuclear Regulation’s decision to grant consent for a

decommissioning project at Wylfa nuclear power station to the licensee, Magnox Ltd, under

the Nuclear Reactors (Environmental Impact Assessment for Decommissioning) Regulations

1999 (as amended).

The process of assessing the potential environmental impacts of the project has involved

extensive public consultation. I believe that the process has been open and inclusive and I

sincerely thank everyone who has been involved in this important work, especially those who

took the time to send comments on the documentation provided by the licensee.

All of us, and particularly the local population, have a keen and vested interest in the

avoidance or minimisation of potential environmental impacts during the decommissioning of

Wylfa nuclear power station. We have attached conditions to the consent to ensure the

continued effective management of the environmental impact of the project. This indicates a

requirement to make available to ONR and the public an annual Environmental Management

Plan (EMP) which provides information on the progress of the decommissioning work and the

measures being used to minimise the environmental impact. Experience so far has shown

that this provides an effective means of managing potential environmental impacts.

During our decision-making process we have strived to be open and transparent. Openness

and transparency will continue to be a key factor in managing environmental impacts

throughout the coming decades of this decommissioning project. I hope that you will find this

report helpful and that it gives you a clear understanding of the basis for our decision.

Mark Bassett

Programme Director – Decommissioning Fuel and Waste Programme

Office for Nuclear Regulation (An agency of the Health and Safety Executive)

Redgrave Court

Merton Road

Bootle

Merseyside

L20 7HS

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EXECUTIVE SUMMARY

The Office for Nuclear Regulation (ONR), as an agency of the Health and Safety Executive

(HSE), is the enforcing authority for the Nuclear Reactors (Environmental Impact Assessment

for Decommissioning) Regulations 1999 (as amended; EIADR).

The intention of the EIADR Regulations is to involve the public through consultation in

considering the potential environmental impacts of a decommissioning project, and to make

the decision-making process open and transparent.

Since EIADR entered into force in 1999 the decommissioning of nuclear power stations and

other nuclear reactors within the scope of EIADR may only proceed with consent from ONR.

To obtain consent the licensee must submit to ONR an Environmental Statement (ES). The

ES presents a detailed environmental impact assessment for the proposed decommissioning

project and the mitigation measures to be used to avoid or minimise any significant adverse

impacts on the environment, together with a non-technical summary of this information. This

is considered by ONR during an extensive public consultation. If the project is considered

acceptable ONR grants consent for the decommissioning project. It is a requirement that that

decommissioning project starts within 5 years of the consent being granted.

Wylfa obtained consent to decommission in March 2009 on the expectation of ceasing

operation within 5 years of that time. However, due to extended electricity generation Wylfa is

not expected to shut-down completely and begin decommissioning until around the end of

2014 or possibly later depending on their operational plans. By this time the current consent

will have expired and so Wylfa sought a new consent.

Wylfa submitted a new application for consent which included an updated ES. This was

subject to detailed assessment and public consultation. ONR took relevant factors into

account when reaching its decision to grant consent. In brief, these were: the adequacy of the

information provided in the environmental statement; the conclusion that environmental

benefits would far outweigh detriments; the prediction that there would be no significant

effects on the environments of other countries; and the recognition that some issues would be

adequately covered elsewhere, such as through other regulatory regimes. The assessment

gave ONR the confidence to issue consent for the project on 25 September 2013.

The conditions attached to the Consent relate to mitigation measures to prevent, reduce and,

if possible, offset adverse environmental effects of the project. In brief, Magnox Ltd must

prepare an annual environmental management plan (EMP) that identifies mitigation

measures, reports on their implementation, effectiveness, progress of the decommissioning

work and reports on changes to such measures in light of experience. A copy of the EMP

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and its subsequent revisions must be sent by the licensee to ONR and be made available to

the public.

The ONR EIADR team will maintain regulatory oversight of the Wylfa decommissioning

project through a variety of means including review of the annual EMPs, regular liaison with

the site and periodic audits of progress. ONR must be notified by the licensee in advance of

any significant change to a mitigation measure to control any adverse effects on the

environment or if there are any changes to the project that may have a significant and

adverse effect on the environment. Additionally, the EIADR team aim to attend future Energy

Island Forum meetings whenever possible, where developers of major energy developments

on Anglesey, which could interact with the Wylfa decommissioning project, meet to share

relevant information.

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INTRODUCTION

European Council Directive 85/337/EEC1 as amended by Council Directive 97/11/EC2 and

Council Directive 2003/35/EC3 sets out a framework on the assessment of the effects of

certain public and private projects on the environment and on public participation in respect of

the drawing up of certain plans and projects relating to the environment. These are known as

the Environmental Impact Assessment (EIA) Directive.

The EIA Directive is implemented in Great Britain by the Town and Country Planning

(Environmental Impact Assessment) (England and Wales) Regulations 1999, as amended6

(TCPA (EIA)99) and the Environmental Impact Assessment (Scotland) Regulations 1999, as

amended7 The competent authorities for these Regulations are the relevant local planning

authorities.

The Directive is implemented in Great Britain for the specific cases of decommissioning

nuclear power stations and nuclear reactors by the Nuclear Reactors (Environmental Impact

Assessment for Decommissioning) Regulations 1999 (EIADR99)4 as amended by the Nuclear

Reactors (Environmental Impact Assessment for Decommissioning) (Amendment)

Regulations 2006 (EIADR06)5 The enforcing authority for EIADR is the HSE, with

responsibility delegated to ONR. Further information on the EIADR process and the legislative

framework can be found in annex 1.

A Pre-Application Opinion (PAO) is an optional step in which a licensee can seek ONRs

opinion as to the content of their application for consent to decommission. Wylfa submitted a

‘Desktop review’ scoping report in November 2012 in order to obtain a PAO from ONR. The

document laid out the proposed format and content for their application for consent, build

upon the previous ES and update it for the subsequent 5 years. During a 30 day consultation

period, involving statutory consultees (including Natural Resources Wales (NRW) and Isle of

Anglesey County Council (IoACC)), no objections to this approach were raised. The PAO is

available for download from (www.hse.gov.uk/nuclear/documents/wylfa-eiadr.pdf)

An application for consent includes primarily an Environmental Statement (ES), which

presents an Environmental Impact Assessment (EIA) for the decommissioning project and the

mitigation measures to be used to avoid or minimize any significant adverse impacts on the

environment. A non-technical summary is provided to support the ES and to provide

information in a non-technical format.

This document reports on ONR’s decision to grant consent for a decommissioning project at

Wylfa. It describes the main reasons and considerations for the decision, the content of the

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www.hse.gov.uk/nuclear/documents/wylfa-eiadr.pdf

conditions attached to the Consent and a description of the main measures that Magnox Ltd

must take to control any adverse effects of the project on the environment.

Application for consent to carry out a decommissioning project

Wylfa obtained consent to decommission in March 2009 on the expectation of ceasing

operation within 5 years of that time. However, due to extended electricity generation Wylfa is

not expected to shut-down completely and begin decommissioning until around the end of

2014 or possibly later depending on their operational plans. By this time the current consent

will have expired and so Wylfa sought a new consent.

In November 2012 Magnox asked ONR to provide a Pre-Application Opinion (PAO) on the

proposed approach towards gaining consent to decommission Wylfa. The PAO was published

in February 2013.

The PAO process made reference to a ‘Desktop Review’. Following discussions with

Stakeholders following the PAO, Magnox made a decision to name the update document as

the Environmental Statement: 2013 Update. It was considered by Magnox and Stakeholders

that this terminology was clearer and more appropriate than the term ‘Desktop Review’ as

used in the PAO.

The Wylfa scoping report presented the proposed format and content of an application

submitted to ONR as an application for EIADR consent. The proposed approach is to conduct

an update to thoroughly review the original ES, review the proposed decommissioning

methods and mitigation measures to be used and address any contemporary issues. ONR

accepted that this was an appropriate and pragmatic approach and is detailed in the ONR

PAO (www.hse.gov.uk/nuclear/documents/wylfa-eiadr.pdf).

After due consideration and taking into account comments received from consultees, ONR

identified below a number of specific points and issues that should be addressed in the

2013ES update. It was noted that these should be considered in conjunction with the previous

PAO, which contains still pertinent opinion and advice.

a) The desktop review will appropriately review the environmental impact of the

decommissioning work and the required mitigation measures to avoid or minimise

any environmental impacts. As indicated in the scoping report it is essential to

consider where technology and approaches may have moved on since the original

ES was created to ensure that best practice is utilised for the decommissioning works

and mitigation measures etc.

b) In relation to mitigation measures it is important that their effectiveness can be

judged. The desktop review should consider where it may be necessary to collect or

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www.hse.gov.uk/nuclear/documents/wylfa-eiadr.pdf

generate baseline/background data for reference and later comparison as the

decommissioning work is underway, for instance to establish background levels of

dust and noise on site. Similarly, plans for regular or periodic surveys, e.g. for

ecology or wildlife, should be considered.

c) The desktop review will appropriately consider the potential impact of the

decommissioning project at Wylfa with other large-scale projects on Anglesey. This

will mainly cover the proposed adjacent development of the proposed new nuclear

power station but should also cover other developments such as those that form part

of the Anglesey Energy Island Programme (EIP), as appropriate. The consideration

should include issues such as:

i) Potential for combined and cumulative impact with these other projects

ii) Potential synergies between the projects, for instance in traffic management or

utilisation of share facilities such as the marine offloading facility planned for the

proposed new nuclear power station

iii) Socio-economic impacts, such as the impact on local jobs, impact on the Welsh

language and tourism

Wylfa are encouraged to work with these other projects where possible to share

intelligence, best practice and environmental data etc, although it is acknowledged

that the extent to which this can be done may be limited due to commercial or legal

reasons.

d) There should be a review of the regulatory framework and legislation that applies to

the decommissioning project to identify any revised or new legal duties or

responsibilities etc. A side-by-side comparison of current and 2009 legislation in a

table might be a particularly effective way to present this. Similarly, there are a

number of other plans and strategies of relevance to major projects on Anglesey that

may be considered in the review as appropriate, examples may include:

i) The Anglesey Landscape Strategy Update 2011

ii) Area of Outstanding Natural Beauty Plan (2009-14)

iii) Section 85 of the Countryside and Rights of Way Act 2000

These documents are available for download from

http://www.hse.gov.uk/consult/condocs/cdwylfa/cdwylfa-documentation.htm or by request to

ONR or Magnox.

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http://www.hse.gov.uk/consult/condocs/cdwylfa/cdwylfa-documentation.htm

Magnox applied to ONR for consent to carry out a decommissioning project at Wylfa. For the

application Wylfa submitted the following documents:

• an ES, which presents a comprehensive Environmental Impact Assessment for the

decommissioning project

• a non-technical summary of the ES

• the documents submitted previously to obtain the current consent

ONR consulted extensively on the ES, the consultees are listed in Annex 2. In addition,

Magnox publicised the environmental statement in the local press (Bangor Mail, Daily Post

and the Holyhead and Anglesey Mail) to involve local people. ONR conducted a 3-month

public consultation exercise, running from 7 May to 9 August 2013 which was also publicised

in the local press, in local libraries to site and on the ONR website. The consultees who

responded and were content for their comments to be made publicly available are listed in

Annex 3. Copies of these responses were sent to the licensee, and can be inspected at public

libraries close to the site, and HSE’s Knowledge Centre and local area office.

Organisations involved in the consultation process

ONR considered the environmental statement for Wylfa. ONR’s consideration included

holding discussions with ONR’s site inspector for Wylfa and stakeholders as well as taking

into account written comments received during the public consultations.

The organisations and agencies with expertise in planning and environmental matters (the

consultation bodies) reviewed the ES as appropriate, and ONR took into account their

findings.

Request for evidence to verify information within the environmental statement

ONR was of the opinion that further information or evidence was not necessary before it could

make its decision and no additional information was requested by consultees. Copies of the

environmental statement are available for public inspection at public libraries close to the site,

HSE’s Knowledge Centre and HSE’s local area office for a period of one year from the date of

the Consent granted by ONR (that is, until September 2014).

ONR also took account of the views of the other organisations it consulted and which

provided comments (see Annex 2). These organisations have expertise, knowledge or

interest in nuclear, planning and environmental matters.

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Review of the Environmental Statement Introduction

The ES submitted to support the application for consent provided all the information required

to fully describe and assess the potential environmental impact of the decommissioning

project. The content provided all the relevant information indicated in Schedule 1 of EIADR.

As described above, the ES built upon the previous 2008ES, bringing it up to date for the

subsequent five years and also addressed additional issues highlighted by key stakeholders

in the PAO.

Changes 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 the an alternative package design is the best approach for storing

some forms of radioactive waste and now use 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.

The proposed option for operational ILW that is to be retrieved and re-packaged during Care

and Maintenance Preparations has changed since the 2008 ES was issued. The 2008 ES

baseline was to retrieve this waste from its current storage location, then encapsulate and

package in appropriate storage containers. Retrieved intermediate level waste (ILW) will now

be placed directly into Ductile Cast Iron Containers (DCICs) without encapsulation. This

relates to approximately 50 cubic metres of ILW, which will require up to 20 DCICs. ILW

currently stored in the reactor equipment building voids will be left to Final Site Clearance and

there has been no change to this approach (this is the majority of ILW at the site,

approximately 820 cubic metres).

Magnox now places far more emphasis on the use of the waste hierarchy to manage low level

waste (LLW), in line with the Nuclear Decommissioning Authorities (NDA) published strategy.

However as in the 2008ES all LLW will be packaged and taken from the Site, but now there is

greater emphasis on sorting and segregation of LLW, to allow best use of the waste

hierarchy.

Review of the environmental impact of the decommissioning project

The ES covers a wide range of environmental aspects, and for each provides an assessment

of the likely environmental impact. These have been reviewed in detail by ONR, taking into

account comments received from respondents of the consultation. These reviews are

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presented below, together with an overall assessment of the environmental impact of the

decommissioning project

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Air quality and climatic factors ONR Review

The potential for the decommissioning work to impact on air quality was assessed in detail in

the 2008ES. Three major topic areas were identified that could have an adverse impact:

traffic emissions, dust from on-site activities (such as demolitions), and dust deposited by

vehicles along traffic routes.

The likely emissions from traffic were assessed using standard methodology (set out in the

Department of Transport/Highways Agency’s Design Manual for Roads and Bridge) and

predicted levels of emissions were assessed for significance by reference to national air

quality objectives (AQO) for common traffic pollutants, including carbon monoxide, nitrogen

dioxide and PM10 particulates. With the expected level of heavy good vehicles (HGV) and

other traffic involved in the decommissioning project the level of emissions is not expected to

exceed the AQO levels.

The potential for dust to be deposited along traffic routes was considered significant. To

address this, a number of appropriate mitigation measures, including using sheeting on

vehicles carrying dusty materials, vehicle wheel and body washing, will be used and are

expected to be effective. More generally, dust monitoring will be undertaken during any

activities that could create dust, such as demolitions or in-filling. There will be comprehensive

dust monitoring, including using directional dust monitors to determine the source of the dust

(i.e. whether from the decommissioning or potential new build project), and visual inspections

in the vicinity of the site boundary. This information will be used to target appropriate

mitigation measures and assess their effectiveness. Water sprays will be used during dusty

operations as a common mitigation measure.

The 2013ES recognises the potential for cumulative impact, particularly with Horizon’s

proposal for a new nuclear power station adjacent to the Wylfa site. The impact of the

combined traffic will be assessed in due course, although it is not expected to raise traffic

emissions above acceptable levels. Similarly, Wylfa intend to pursue a collaborative approach

to dust monitoring with Horizon if possible.

Overall, the 2013ES found the 2008ES conclusions and identified mitigation measures to still

be valid. The potential cumulative impact with the new build project was highlighted and will

be taken into account as that project progresses.

Consultation Comments

No comments received.

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Conclusion

ONR is satisfied with the identified impacts and mitigation measures for air quality and

climatic factors.

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Archaeology and cultural heritage ONR Review

The potential for the decommissioning work to impact on archaeology and cultural heritage

was assessed in detail in the 2008ES. 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 2013ES update identified several new or revised impacts that were not assessed in the

2008ES. These include, designated assets, archaeology, historic landscape and built

heritage. Appropriate updates were conducted that include recording industrial heritage,

performing walk-over studies and consulting with the Gwynedd Archaeological Trust and the

Royal Commission on the Ancient and Historical Monuments of Wales. Specific impacts were

identified, which include a major adverse impact upon industrial archaeological assets from

the complete removal of Wylfa. However, its removal would reform the landscape to its former

self, therefore having a moderate beneficial impact upon the landscape; this effect would be

permanent.

The significance of the industrial heritage was recognised by Magnox and its structures

(including any surviving military installations) will be recorded at an appropriate level before

dismantling works are undertaken and records and photographs relating to its construction

and decommissioning and use will be deposited in an appropriate archive.

The 2013ES recognises the potential for cumulative impacts. It reports that the adverse

cumulative impact of the proposed new nuclear power station at Wylfa would balance out the

beneficial impacts of decommissioning Wylfa upon the listed buildings and historic landscape

leading to a neutral impact upon these cultural heritage assets. However, it also recognises

that during the construction period for the proposed new nuclear power station at Wylfa, there

would be cumulative adverse effects upon the setting of these historical assets. However,

this effect is not considered to be significant.

There would be no cumulative impact upon the below ground archaeological remains, as the

proposed decommissioning works are not affecting this resource.

Overall, the 2008ES assessment and mitigation measures remain valid. The 2013ES

identified several new or updated impacts, and appropriate mitigation measures were

identified.

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No observations or comments received.

Conclusion

ONR is satisfied with the identified impacts and mitigation measures for archaeology and

cultural heritage.

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Ecology ONR Review

The potential for the decommissioning work to impact on ecology was assessed in detail in

the 2008ES. The significance of impacts was determined in part on the nature conservation

value of the ecological receptors (populations or habitats) affected. This approach takes into

account factors such as the degree of legal protection extended to a receptor and the species

or habitat rarity in local or national contexts.

A number of potential significant impacts were identified; these included loss of some habitat,

disturbance of several species, including birds and bats, risk of accidental killing of adders

and disturbance to sea creatures during demolition of off-shore structures.

Appropriate mitigation measures for all of these impacts were identified. These include

scheduling major works for outside of the bird breeding season, use of directional lighting to

minimise the effect of light spill on foraging bats, bat surveys in buildings prior to demolition

and carrying out marine explosions at low tide and when no marine mammals are observed in

the area.

Ecological data is generally considered to remain valid for around 2-3 years, depending on

the species and habitat investigated. The baseline ecological data from the 2008ES has been

reviewed and updated where possible following a site walkover survey in 2013. Few changes

were identified. The baseline conditions for breeding bird species in the Ynys Feurig, Cemlyn

Bay and The Skerries Special Protection Area (SPA) were identified for update through a

targeted survey which demonstrated that the SPA will not be significantly affected by the

decommissioning project.

Further ecological surveys will be conducted at appropriate intervals through the

decommissioning project. For instance, updated surveys for a range of legally protected

species (including badgers, otters, water voles, bats) will be undertaken one year before the

commencement of any works that could affect these species, and supplemented by on-going

monitoring by an Ecological Clerk of Works during such works.

The 2013ES highlighted that a pair of choughs, a specially protected species listed on

Schedule 1 of the Wildlife and Countryside Act 1981, have bred within a dry-cell building on

site. Loss of nesting sites and noise and visual disturbance would have an adverse impact on

breeding choughs. As mitigation for this, suitable nest boxes will be provided prior to

decommissioning work, and work will be undertaken outside of the breeding season.

An assessment of the potential impact of the decommissioning on the SPA, as required by

Article 6 of the Habitats Directive, was performed. No significant effects were highlighted. The

22

assessment will be kept under review, particularly in light of the proposed new nuclear power

station adjacent to Wylfa.

The 2013ES also considered the permanent loss of warm water discharges into Cemaes bay

on marine flora and fauna. Wylfa have conducted appropriate modelling work to establish the

appropriate location for an alternative discharge pipe once the main pumps are turned off to

achieve at least as good dispersion as when the station was operational.

The 2013ES assessed the impact on reptiles. As a precautionary measure, the mitigation

described in the 2008ES to prevent the incidental mortality of adders will be extended to

include all suitable reptile habitats 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.

Overall, the 2008ES assessment and mitigation measures remain valid. A new potential

impact on breeding choughs was identified in the 2013ES update, and appropriate mitigation

measures were identified.


NRW made a number of comments. They highlighted that, as suggested in the ES, updated

otter, badgers, water voles and bats and other legally protected species survey are required

one year prior to the commencement of any works that could affect these species, and that

the any measures to provide a net gain for biodiversity, including habitat restoration following

site clearance, should be discussed and agreed with NRW and the IoACC before being taken

forward.

To complement ONR’s advice, NRW encouraged close and collaborative working between

the Wylfa site and Horizon with regards to ecological issues including mitigation.

The demolition of buildings will result in the loss of sites with moderate or high potential to

support roosting bats; in particular, building 99 which supports a roost of common Pipistrelle

bats. NRW highlighted the need for European Protected Species Licenses (EPSL) for the

commencement of such work. It is noted that such licences always require a comprehensive

mitigation plan based on up to date survey results.

To protect bats, NRW indicated the need for a programme of internal inspection and survey

work on all buildings with ‘moderate’ or ‘high’ potential to support roosting bats, to ensure safe

exclusion of bats from the buildings prior to demolition and to ensure their favourable

conservation status. For building 99 it was noted that surveys should be carried out at least

23

every two years. NRW would expect future reviews of the EMP to include details of such

survey work.

NRW points out that the potential use of explosive demolition as part of the intake jetty

decommissioning would result in substantially elevated levels of suspended sediment in the

water column possibly resulting in smothering of sensitive habitats and species. To this effect,

NRW would recommend the undertaking of a sediment transport modelling to more

accurately predict localised and more far afield effects.

NRW highlight that Marine Mammal Observers (MMOs) may not establish the presence of

cetaceans (such as whales, dolphins and porpoises) and seals as effectively as underwater

acoustic devices, especially in poor conditions. MMO's would only be effective in good

visibility and calm sea states (85% of

their time at sea submerged, so they are likely to be present when observers do not see them

at the surface. However, there is mixed opinion on the use of these and care needs to be

taken in the choice of model and the use of them because they can cause damage to hearing.

Horizon recognises the need for further time-critical ecological surveys by Magnox to take

place during the decommissioning project, and the need for additional ecological mitigation

activities.

Horizon also welcomes the report’s commitment to explore opportunities for collaboration

between the Decommissioning and new build projects in relation to environmental mitigation

measures and assessment of cumulative impacts. In order to explore the opportunities, a

working group has been set up between Magnox and Horizon.

Horizon highlight that the 2013ES states that there is no record of otters and water voles

within 2km of the Wylfa site boundary. Horizon has been undertaking ecological surveys

within the vicinity of Wylfa since 2009 and can confirm that these species are indeed present

at the site within 2km of the site boundary. Recent surveys undertaken by consultants on

behalf of Horizon have also identified great crested newts to be present on proposed site.

In relation to the implementation of ecological mitigation measures the document identifies

potential measures for providing a net gain for biodiversity including; habitat restoration

following Final Site Clearance, the provision and maintenance of additional artificial

nesting/roosting sites for birds and bats, the provision of reptile hibernacula within the Wylfa

24

Nature Trail in areas that would not be impacted by Wylfa or the proposed new nuclear power

station at Wylfa, and/or financial investment into other nature conservation projects within the

local area.

The land identified for mitigation is owned by Horizon; therefore Magnox will need to liaise

with Horizon to determine if the measures they propose are possible. Whilst Horizon remains

committed to environmental mitigation and keen to cooperate, it is not yet known whether

these proposals will be feasible and whether the nature trail will be affected by the proposed

new power station. Land that is within the nuclear power station boundary may not be

available for mitigation as it may be required for components of the new nuclear power station

development.

Conclusion

ONR is satisfied with the identified impacts and mitigation measures for ecology and the

comments received. During winter months there may be light spill from working areas into

areas used by bats for foraging. However, normal working hours will be between 07:30 to

17:30 and light spill will be minimised by the use of directional lighting. Light spill is therefore

unlikely to affect bats during the spring, summer and autumn months when they are active

and will not affect the favourable conservation status of bat species using the site.

Further recommendations include that Wylfa is to maintain and continue to liaise with the

IoACC, NRW and Horizon with respect to protecting known and newly found species,

conducting decommissioning works where appropriate and with the methods used. ONR

would expect that progress and developments within ecology would be reported upon within

the annual EMP submission.

25

Geology, hydrogeology and soils ONR Review

The potential for the decommissioning work to impact on geology, hydrogeology and soils

was assessed in detail in the 2008ES. The methods used to assess significance in the

2008ES were determined on the basis of whether there would or could be a change in

restrictions on land or groundwater use. An assessment would also be made to see if a

change in monitoring and reporting would be required, if there would be a change in

regulatory processes or if there would be a requirement for remediation.

In determining the significance of any impacts Magnox considered local groundwater uses,

ecological sensitivity, statutory designations and the effect of distance in reducing any

changes to water quality or flow.

In the 2008ES Magnox identified a number of potential adverse impacts on geology,

hydrogeology and/or soils arising from the decommissioning process. These potential effects

include changes to ground and groundwater quality and/or groundwater quantity (levels and

flows), which include but are not limited to inadvertent or uncontrolled disturbance or

spreading of existing contaminated soils, the creation of new migration pathways, direct

rainfall infiltration, caused by changes in ground coverage and temporary open excavations,

resulting in the mobilisation of existing contamination.

Magnox predicts that these potential adverse impacts will predominantly arise during the Care

and 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. Mitigation measures put in place will involve following best practice and/or all

applicable British Standards (BS) or Environment Agency (EA) Pollution Prevention Guidance

(PPG) Notes such as following the guidance contained within PPG 22 – Dealing with Spills

and mitigations to deal with sub-surface structures. With these in place none of the residual

impacts are predicted to be significant.

The 2013ES highlighted additional impacts and mitigation that will need to be put in place

during decommissioning (following updated guidance such as the Nuclear Industry Group for

Land Quality and the Qualitative Risk Assessment for Land Contamination including

Radioactive Contamination, December 2011) including the production of a qualitative risk

assessment and a specific review to establish the impacts of dewatering activities. Updates

in legislation were also identified that include the Water Resources Act 1991 (as amended),

the Environmental Permitting regulations 2010 and Directive 200/60/EC Establishing a

Framework for Community action in the field of water policy (Water Framework directive). The

2008ES did not assess for the proposed new nuclear build, therefore the 2013ES considered

the potential cumulative impacts from these two projects. Depending on timelines, the

26

cumulative effects identified are likely to arise from the disturbance and mobilisation of

contaminants in soils and the disruption of groundwater interfaces. Additional impacts over

and above those presented in the 2008ES were the impact of the below ground structures on

site as a contaminant source. Another cumulative impact identified is the cumulative impact

on soils and groundwater flow, and the quality of these to the Site of Special Scientific Interest

(SSSI) site from the proposed new nuclear build. Other potential cumulative impacts include

the impact of inadvertent effects of dewatering on groundwater resources and nearby

abstractions, watercourses and sites of conservational interest, including the risk of

mobilisation and contaminants into the area (from spills or leaks of non-radioactive

substances for example).

The 2008ES assessment and mitigation measures remain valid. The 2013ES highlights

additional impacts and mitigation that will need to be put in place during decommissioning.


A Conceptual Site Model (CSM) (A CSM is a representation which sets out the critical

pollutant linkages of concern for a particular land contamination problem) for the Wylfa was

originally published in 1996. NRW recommended that before any risk assessments for

controlled waters are undertaken that the CSM is reviewed to take account of information

from more recent site investigations and more recent guidance on the construction of

conceptual site models. Redundant boreholes should be decommissioned to ensure the long

term, protection of groundwater quality and resources.

Conclusion

ONR is satisfied with the identified impacts and mitigation measures for geology,

hydrogeology and soils and the comments received. ONR would recommend that the CSM is

reviewed by Magnox prior to risk assessments for controlled waters being undertaken.

27

Landscape and visual ONR Review

The potential for the decommissioning work to impact upon landscape and visual effects was

assessed in the 2008ES. A three stage process was adopted for the evaluation of the

significance. First, the magnitude of the landscape or visual impact was assessed. This was

followed by an assessment of the sensitivity of the landscape resource or visual receptor.

Using these two assessments, the significance of the impact was then judged for each

assessment stage.

The assessment concluded that in the long-term the decommissioning project will provide

considerable benefit to the landscape and visual character of the area. Twenty-seven

character areas/view locations were assessed for visual impacts. Eight landscape attributes

were assessed. For each of the visual landscape areas/attributes the impact and mitigation

were described for each decommissioning phase.

With respect to landscape attributes, no significant adverse impacts were identified. Following

final site clearance, very long-term beneficial significant impacts were identified for the built

environment at the Wylfa site as all plant and structures will have been demolished.

The 2013ES assessment concluded that the methodology in the 2008 ES remains current,

although it was recognised that the Guidelines for Landscape and Visual Impact Assessment

2002 3rd edition has recently become available and is presently being reviewed by Magnox in

the context of the decommissioning project. It is not anticipated that new baseline data (that

includes Ordinance Survey mapping data) will require any changes to the mitigation in the

2008 ES.

The 2013ES included a landscape and visual impact assessment that addressed 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. Since

the submission of the 2008ES various relevant strategy documents have been published,

such as the Countryside Council for Wales Tranquil Areas Map 2009 and the Isle of Anglesey

County Council Landscape Strategy Update 2011. Magnox noted that the planning policies

relevant to the development are the same as those that existed at the time the 2008ES was

prepared. Magnox will update their baseline documents as appropriate to reflect these

strategy and policy documents.

The assessment of the Seascape in the 2008ES was limited to the assessment of effects on

views from the coastal path. As Wylfa is a significant coastal feature, Magnox will carry out a

Seascape assessment at a future date when information regarding the proposed new nuclear

power station becomes available. Magnox anticipate that this will be a joint assessment

28

between Wylfa and Horizon and will agree the methodology with NRW and the IoACC

appropriately.

It is noted that the assessment of cumulative effects is currently limited by the lack of

information available for other developments. However it is likely that the construction and

operation of the proposed new nuclear power station at Wylfa may negate to some extent the

beneficial effects identified in the 2008ES. In some cases there may be the potential for

significant cumulative adverse effects as a result, particularly if the proposed new nuclear

power station at Wylfa results in changes to the woodland and artificial drumlin landscape

(designed by Dame Sylvia Crowe) which was used as mitigation for the impact of the current

Wylfa site. It is understood this designed landscape is in the process of being reviewed by

Cadw (the Welsh Government’s historic environment service) in terms of it being included in

the register of landscapes, parks and gardens of historic interest in Wales. Any progress with

the assessment of cumulative effects will be reported in the annual EMP and possibly

discussed at the Energy Island Initiative to effectively engage with other stakeholders.


identified various new published documents and additional baseline data. These have been

included within the update as appropriate.


The IoACC indicated that the re-cladding of the reactor building may need to be thought

through with consideration to the possibility of 'glinting'. The colouration of the reactor building

and its effects on the visual impact should also be considered. The IoACC considers that the

de-commissioning phase needs to achieve better levels of mitigation and demonstrate

appropriate outcomes to the predicted adverse landscape and visual impacts identified.

Conclusion

ONR is satisfied with the identified impacts and mitigation measures for landscape and visual.

ONR would recommend that Wylfa considers the comments received and the visual impact of

re-cladding the reactor building and to continue to assess and mitigate where appropriate.

29

Noise and vibration ONR Review

The potential for the decommissioning work to have impacts on the environment from noise

and vibration was assessed in detail in the 2008ES. The significance was determined largely

on the basis of the change in noise level and receptor sensitivity with residential properties

being considered as high sensitivity. The most significant impact of noise and vibration will

occur during care and maintenance preparations when the bulk of the demolition work will

occur. For general site works (with no mitigation) Magnox assessed the worst-case noise

impacts during Care and Maintenance Preparations were predicted to be significant at seven

residential locations and at the Wylfa Power Station social club located within the area of the

former Simdda-Wen. At five receptors the impacts are assessed as not significant.

For the care and maintenance phase, no adverse effects were identified as the site will be

largely quiescent during this phase with very little on-site activity. Following final site

clearance, the cessation of activities on site and associated traffic will result in long-term

permanent beneficial effects.

During the care and maintenance preparations and final site clearance, traffic, noise and

vibration due to increased traffic on the main road network were identified as having no

significant adverse impact. Direct noise from work on site was identified as having up to

significant adverse impacts on residents. Various mitigation measures to reduce the noise

impact were identified, including appropriate scheduling and duration of work activities, such

as avoiding Heavy Good Vehicles (HGV) traffic between 19.00 and 7.00 hours, and use of

quiet working methods where available,

The 2013 noise and vibration assessment took into account noise and vibration deriving

directly from the Wylfa site, as well as that due to site traffic (including the use of HGV’s). The

traffic data used in the assessment took into account predictions of future changes in

background traffic.

Magnox considered, and agreed with the IoACC that 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 IoACC. The Section 61 agreement is a formal agreement between

Wylfa and the IoACC where noise levels, hours of work and any mitigation are agreed upon.

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. Magnox will assess the decommissioning noise impacts in line with 'Best

30

Practicable Means (BPM)' found in BS5288:2009. The mitigation will need to be specific and

demonstrate to the IoACC that agreed noise limits will be met.

These mitigation methods are expected to effectively mitigate noise impacts. However, as

indicated in the 2008ES, it is stated that it is not possible to indicate with confidence the level

of noise reduction that would be gained. As such there will be the need for continued noise

monitoring through the work activities. Overall, the 2008ES assessment and mitigation

measures remain valid. 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.


The IoACC provided requirements for real time noise monitoring with remote access to

enable noise to be managed proactively in line with a set of agreed thresholds.

NRW note that with regard to explosion noise and vibration impacts on cetaceans there must

be appropriate mitigations in place (as described in detail in the ecology section above).

Conclusion

ONR is satisfied with the identified impacts and mitigation measures for noise and vibration.

ONR would recommend that Wylfa further consider the use of the proposed explosives with

regard to the noise and vibration impacts to cetaceans in-water, and assess the associated

mitigations measures appropriately.

31

Socio - economic ONR Review

The potential for the decommissioning work to impact upon socio-economic factors was

assessed in detail in the 2008ES.The main impacts considered under this topic were changes

to direct and indirect employment supported by the power station. Mitigations for this include

retraining and re-skilling the existing power station workforce to enable their employment in

the decommissioning works. Magnox also assessed the effects on employment and

unemployment levels in the local economy, and changes to the structure of local employment,

population, expenditure, housing and accommodation and schools. Magnox considered other

impacts but in less detail , including changes in commuting patterns, effects on key local

economic sectors, changes in the development potential of the area and changes in the

incidence of social problems including crime and disorder.

There is no specific methodology for this type of assessment; however it is considered that

methods and mitigation measures referenced in the 2008ES remain valid. To appropriately

assess socio-economic impacts Magnox sub-divided Anglesey into three areas in order to

capture localised impacts. The significance of these impacts was determined on the basis of

the magnitude of the predicted impact, the geographical extent on the impact, its duration, the

capacity of the local economy to absorb or adjust to the impact and typical rates of socio-

economic changes experienced in the study area. The scope for Magnox to avoid or reduce

the significant adverse impact for the local economy is accepted as being relatively limited.

Magnox will implement mitigation measures to assist individuals affected by the closing down

of the site, for instance by facilitating redeployment where opportunities exist.

The 2013ES identified that updates were needed for the socio-economic elements of the

baseline. Population growth is a significant factor in determining future economic growth for

the Island. Magnox report that the most recent data shows that there have been a declining

population in Anglesey in the five years up to mid-2007/08. Despite there being slightly

declining population projected for the first few years of the projection period, natural change is

projected to become negative in 2018/19 and this is expected to continue for the rest of the

projection period. This and potential changes in demographics, such as an aging population,

may have to be considered when identifying mitigation measures.

Anglesey is one of only eight local authorities in Wales that are projected to generally see

more deaths than births across the whole projection period. Without a positive net inward

migration, the Isle of Anglesey would see a declining population (Welsh Assembly Statistics,

National Statistical Directorate for Wales). Over a ten year period, the population of the study

area has increased (using official mid-year estimates from 2001 and 2011) but at a much

slower rate than Wales (1.60% compared to 5.28%).

32

Magnox assessed the impact on the Welsh language as a result of the decommissioning

works. A survey undertaken in 2012 as part of the Shaping the Future initiative (for Wylfa and

Trawsfynydd nuclear power stations) received 364 replies (out of 842 potential recipients).

Out of those replies, 37% stated they understand the Welsh language (includes speaking,

reading and writing). 2011 Census data states that 38,568 people within Anglesey are able to

speak Welsh. The age cohorts with the largest numbers within them were for those aged

between 10 and 14. There is no specific methodology for this type of assessment, although a

suggested mitigation measure would be to provide input into a Welsh Language Impact

Assessment prepared by the owners of the proposed new nuclear power station. In addition,

Magnox report that the types of socio-economic effects to be addressed in an ES for

decommissioning projects are not specified in the relevant regulations of EIADR. Therefore,

Magnox considers that the methodology used in the 2008ES remains valid.

Magnox considers that the main source of cumulative impacts would be in relation to the

construction and operation of the proposed new nuclear power station at Wylfa (this was not

addressed in the 2008 ES) as there may be an overlap between the two projects, although

this is not currently known. With both projects potentially taking place concurrently the overall

loss in jobs from decommissioning Wylfa is not likely to be as significant on the local economy

as reported in the 2008 ES as staff may be redeployed to the new build project. Magnox note

that impacts on Anglesey’s local economy are likely to be beneficial due to the number of staff

required to construct and ultimately operate the proposed new nuclear power station at Wylfa,

even if this is for a limited number of years. However, given that little information is currently

known about the proposed new nuclear power station, no further assessment can be made at

this stage with regard to the potential cumulative impacts with the decommissioning of Wylfa.

However, Magnox have identified 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 re-

training 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

33

• 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.

Many other large-scale projects are planned for Anglesey that may have beneficial cumulative

impacts on socio-economic interests and are also likely to arise with the

construction/operation of the developments associated with the Anglesey EIP (as discussed

in the cumulative impacts section below).

Overall, the 2008ES assessment and mitigation measures remain valid. Significant updates

and changes have been assessed for the 2013ES. Wylfa will continue to assess the potential

for cumulative effects through partnership working with stakeholders on the Island and

through reporting impacts in the EMP.


The most significant concerns from the IoACC arise through the loss of employment and

income for the local population. Their comments note that decommissioning will cause a

number of significant economic impacts, including:

• Short and long term adverse impact on employment opportunities in the Anglesey

North sub-area by the end of Care and Maintenance Preparations (10 years).

• Generation of employment for almost a decade during Final Site Clearance. This may

provide significant employment but will be for a relatively limited period.

They acknowledge that the ability of Magnox to directly avoid or reduce the significant

adverse employment impacts during decommissioning is limited. The scope for redeployment

or retraining of staff within Magnox will be constrained and, although assisting the individual

affected, this will still not prevent the long term loss of stable and well paid employment

opportunities within the local economy. The mitigation measures are not expected to lead to

any sizeable reduction in the magnitude or significance of the predicted socio-economic

impacts.

An array of public sector initiatives is aimed at changing the economic characteristics of the

area, to prevent it from setting into low performance equilibrium. The IoACC is committed to

the creation of a modern infrastructure base to support the diversification of the area’s

economy.

Given the scale and complexity of the decommissioning project (together with the on-going

deterioration in the island’s socio-economic conditions) the IoACC believe that more detail

34

should have been included in relation to its significant potential socio-economic impacts and

issues.

The IoACC is disappointed in that they believe no meaningful attempt has been made to

identify and assess potential cumulative impacts and the combination effects of all major

infrastructure projects on Anglesey in relation to this decommissioning project. The IoACC

facilitated a Workshop on the 12th July 2013 that encouraged greater collaboration and co-

operation between all developers of major energy projects on Anglesey. ONR note that

Magnox attended the workshop to capitalise upon the opportunity to contribute to improve its

understanding of the proposed major infrastructure projects on Anglesey – which could help

underpin and inform a more robust cumulative impact assessment.

The IoACC believes that the ES fails to sufficiently consider the potential socio economic

impacts (and mitigation) of the decommissioning project on the island’s tourism sector and the

Welsh language and culture. The IoACC feel that these should be considered as significant

issues that require appropriate consideration and assessment. They also believe that the

scale of the decommissioning project warrants both a Tourism Impact Assessment and a

Welsh language Impact Assessment to ensure that potential impacts are identified, and

appropriate and meaningful mitigation measures are proposed.

Conclusion

ONR is satisfied with the identified impacts and mitigation measures for socio-economic

factors. ONR notes that the ability of Magnox to directly avoid or reduce the significant

adverse employment impacts during decommissioning is limited. It is recommended that

Wylfa continue to liaise with the IoACC to ensure that adverse impacts on the Welsh

language, employment and tourism are minimised where possible. ONR would also

encourage Wylfa to keep updated upon and make appropriate assessments of the impact of

the decommissioning work on Welsh language, employment and tourism as the project

progresses. ONR would expect that this information would be provided within the annual

EMP.

35

Surface water quality, drainage & discharges ONR Review

The potential for the decommissioning work to impact on surface water quality and drainage

was assessed in detail in the 2008ES. It reports that pathways exist that could cause impacts

to the terrestrial and coastal surface waters via contamination and drainage, in proximity to

Wylfa power station during the decommissioning process. During Care and Maintenance

Preparations and Final Site Clearance activities such as demolition, excavation, soil handling,

construction and the movement of plant/traffic have the potential for releasing sediments to

terrestrial and coastal waters for example. The significance of impacts was determined on the

basis of whether there would a change in compliance with specified short term environmental

assessment levels or environmental quality standards or there would be an increase or

decrease in the number of discharge permits required. The significance of impacts was also

determined on the basis of whether an existing permit would be breached, if there would be a

requirement for remediation or if restrictions on surface water use would have to be

introduced.

A number of potential impacts were identified such as discharges and contamination. Coastal

waters are considered to be at greater risk from the potential of spills and leaks of non-

radioactive substances due to their proximity and linkage via the drainage systems. Various

‘natural’ impacts were assessed including tidal flows, storm surges, flooding, erosion, climate

change, sea levels and weather protection. The analysis concluded that due to the position of

the power station and the nature of the geology of the coastline, the site is well protected

against the potential risks and threats identified.

The 2013ES primarily assessed 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 and changes in the risk of on-

or off-site flooding as a result of decommissioning. It also considered 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, discharges, sediments released due to movements of HGV’s 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 water bodies.

The 2013ES included updates to baseline data with regard to terrestrial and coastal waters

and the new data corroborates the 2008ES assessment of the sensitivity of the water

environment within the study area. As a result there is no requirement for revision of the

36

magnitude or overall significance of the predicted impacts or mitigation measures and the

conclusion of the 2008ES still holds.

Magnox considers that the proposed new nuclear power station has the potential to result in

cumulative impacts on the surface water environment. This large scale development is to be

located on land that also drains the Afon Wygyr and the coastal waters adjacent to Wylfa. As

the sites are both located within the same watershed there is potential for cumulative impacts

of a higher magnitude/significance on terrestrial and marine water quality, catchment

hydrology (infiltration and rainfall runoff patterns and rates) and pluvial flood risk. Little

detailed information is currently available regarding the proposed new nuclear power station.

However, Magnox considers that the potential for adverse cumulative impacts could be

mitigated by the implementation of appropriate environmental management measures e.g.

drainage management plans, and through the adoption of environmental best practice

working methods. These will be considered further as the potential new build project

develops.

The 2013ES assessment identified that there might be the potential to implement water

quality monitoring schemes (for example, visual inspections, spot sampling) during

appropriate stages of the two projects with the aim of verifying the effectiveness of the

mitigation measures that are put in place.


provided updates to the baseline data and the proposed mitigation measures outlined in the

2008ES are considered still relevant and valid in line with current best practice.


NRW highlight that Magnox are currently authorised under Environmental Permitting

Regulations (EPR) to dispose of gaseous and aqueous liquid radioactive wastes into the

environment at Wylfa, for incineration on-site and also for the transfer of certain types of

radioactive wastes to other premises. This authorisation requires the use of the Best

Practicable Means to limit the activity of waste which will require disposal under the

authorisation and also the activity and, where relevant, the volume of radioactive wastes

being disposed of under the authorisation. However, recent amendments to EPR to

implement the Industrial Emissions Directive (IED) mean that incineration now ceases to be a

Part B installation. It is recognised that NRW can set limits in Radioactive Substances

Regulations (RSR) permits to cover non-radioactive discharges and it is proposed to do that

where operators continue to use these units. The current authorisation allows Magnox to

dispose of organic liquid waste by either incineration at Wylfa (subject to the approval of a

relevant incineration unit for oil) or by transfer to a specified incinerator operator It is NRW

policy to review discharges and authorised limits periodically and this would continue to be

done both before the station began its decommissioning and during the decommissioning

37

phase to ensure that discharge limits reflect justifiable operational need and that discharges

and doses to the public remain as low as reasonably practicable.

NRW note that the ES does not include any information on the potential impact of discharges

of radioactive substances to the environment on sites of conservation interest in the vicinity of

the site. In general it is noted that permits for discharges will only be granted where they are

considered to be appropriate, and overall, discharges of radioactive substances to the

environment are expected to decrease significantly during decommissioning.

Conclusion

ONR is satisfied with the identified impacts and mitigation measures for surface water quality,

drainage and discharges. The ES provided information on wastes and potential radioactive

emissions, but notes that disposals including discharges will continue to be made under

Environmental Permitting Regulations (EPR) 2010 and regulated by NRW. ONR also note

that it would be useful if Wylfa considers and makes available information on the potential

impact of discharges of radioactive substances to the environment on sites of conservation

interest on the vicinity of the site.

38

Traffic and transport ONR Review

The potential for the decommissioning project work to impact on traffic and transport was

assessed in detail in the 2008ES. 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 emission

effects of traffic which were considered separately under the topics of noise and vibration and

air quality respectively).

Magnox assessed the traffic impacts 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 also taken into account.

Magnox proposed no specific mitigation measures for the 2008 assessment because the total

traffic levels on these roads were predicted to be at a similar level or lower than those in

2007. In the case of the A5025, although a moderate impact magnitude has been identified

for a short period of time, the total change on these routes is 280 and 306 vehicles to the

north and south respectively and these will be spread throughout the working day. The routes

benefit from accident records below the national averages, therefore it is not considered

necessary to implement specific mitigation measures on these roads.

The 2008ES included collision data for the period between June 2002 and May 2007. Given

that this data is now over five years old, Magnox updated this section for the 2013ES.

Personal Injury Collision data has been obtained from the IoACC for the period January 2008

to December 2012, the latest five year period available. Magnox analysed the collision data

and concluded that it does not indicate any existing issues for pedestrians and cyclists and

shows relatively few collisions involving HGV’s and vehicles performing overtaking

manoeuvres – collision types which, if there was an existing issue, could occur more

frequently if traffic and HGV volumes were increased as a result of the decommissioning.

The 2008ES calculated collision rates for sections of highway (A. power station access road,

B. A5025 north of the power station and C. A5025 south of the power station) to be below

expected levels and overall the collision data shows there to have been a decline in the total

number of personal injury collisions on sections B and C. Magnox therefore concluded that

the updating of the collision data does not increase the sensitivity of the assessed highway

sections.

39

The 2013ES considered the percentage changes in total vehicle numbers and total 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 HGV’s 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, Magnox will prepare and revise where

necessary, an updated Traffic Management Plan 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.

The proposed new nuclear power station at Wylfa would be located adjacent to the site.

Currently Magnox do not know the traffic and transport impacts associated with this proposed

development. It is also unknown what mitigation measures may be developed as part of the

proposed new nuclear power station. Magnox expects that the presence of a new nuclear site

would provide opportunities to reduce the traffic and HGV impacts associated with

decommissioning by working together with the developer. Magnox acknowledges however,

that given the size and proximity of the proposed new nuclear build, it is likely that the

cumulative effects of the decommissioning project and the proposed new build would have a

major adverse effect on the highway network, although it is expected that the majority of the

traffic would be associated with the proposed new development.

Additional new potential cumulative impacts may include the offshore wind farm, the National

Grid connection, the proposed marine offloading facility and changes to access roads. Other

potential projects will assessed appropriately when further information is available.

Overall, the 20

Documents

ONR - Office for Nuclear Regulation - The decision on the … · 2018-11-14 · This document reports on the Office for Nuclear Regulation’s decision to grant consent for a decommissioning