Periodic Safety Reviews

(PSRs) – Presentation to

ENSREG Workshop

Dr. Gary Cook – Office for Nuclear

Regulation (UK)

Overview

• General Overview

• Current Arrangements

• Historic PSRs

• New PSR structure going forward

PSR – A Brief History in the UK

• The first round of PSRs (PSR1) took place in the 1990’s/early

2000’s.

• PSRs generally improved the safety cases, brought in a lot of

hazards missed in the original designs and improved consistency

between the newest and older sites

• PSR2 built on the progress made in PSR1 reviewed the hazards

again and the role of PSA for hazards

• PSR3 introduced a different structure (SSG-25), which is allowing

further improvements and learning

• PSR2 also focussed on material condition, ageing and

obsolescence issues, commensurate with the age of the plants

PSR – Overview in the UK

The need to undertake PSRs is stated as part of the site licence

for all licensed sites (and those authorised by DNSR) within the

UK. This is Licence Condition (LC)15:

1. The licensee shall make and implement adequate arrangements for periodic

and systematic review and assessment of safety cases

2. The licensee shall submit to the Executive for approval such part or parts of

the aforesaid arrangement as the Executive may specify

3. The licensee shall ensure that once approved no alteration or amendment

is made to the approved arrangements unless the Executive has approved

such alteration or amendment

4. The licensee shall, if so directed by the Executive, carry out a review and

reassessment of safety and submit a report of such review and

reassessment to the Executive at such intervals, within such a period and

for such matters or operations as may be specified in the direction

PSR – Overview in the UK

• In addition to the Licence Condition 15 ONR has guidance

documentation for both inspection and assessment of PSRs:

http://www.onr.org.uk/operational/tech_insp_guides/ns-insp-gd-015.pdf

http://www.onr.org.uk/operational/tech_asst_guides/ns-tast-gd-050.pdf

• Both documents are aligned with IAEA guidance on Periodic safety

review of nuclear power plants (Specific Safety Guide No. SSG-25)

http://www.iaea.org

• They also take account and make reference to other ONR guidance,

Safety Assessment Principles and wider documentation such as WENRA

guidance

• PSRs play an important role in ONR’s overall through life regulation to

inform such activities as post outage restart consents and annual reviews

of safety

• PSR is undertaken every 10 years, however other durations can be

applied depending on the position of the plant within the lifecycle

(shutdown, defuelling, decommissioning etc.)

Current Arrangements (EDF Energy)

Process-Based Activities

e.g.

Safety System Reviews

Area-Based Walkdowns

Safety Case Health Reviews

CO

MP

LE

TE

NSC Scoping

Paper

X- 4

ONR

Decision

Date

PSR

Submission

X - 1 X X – 4 years X – 1 years (X-Date)

PSR3 Stand

Back Review

X -3.25 years

Evidence Cut-

off Date

X – 2.5 years

Safety Factor

Head

Documents

X – 2.25 years

Summary

Documents

X – 2 years

Processes continue, and resulting work is managed by normal business processes...

Follow up

presentation

to June NSC

Manage PSR

recommendations

…….to agreed programme

Current Arrangements for EDF fleet (ONR)

PSR

Submission

X- 4

ONR

expectation

that all

findings are

closed out

Decision

letter sent to

licensee and

project report

issued on

ONR website

X - 1 X X – 1 years X – Date (X + 2 years)

PSR

Assessments

start

X -0.75 years

Site visits by

ONR

assessment

team

X – 0.5 years

Sharing of

ONR findings

with licensee

X – 0.25 years

Completion of

assessment

documents,

project report

and decision

letter

X – 0.1 years

Regular interactions and resulting work is managed by normal business processes...

Transfer of

documents/data

onto ONR’s

network

Manage PSR

recommendations

…….to agreed programme

Historic PSRs

Station First PSR Decision

Date

Second PSR Decision

Date

Hinkley Point B

Hunterston B

1997 2007

Dungeness B 1998 2008

Heysham 1

Hartlepool

1999 2009

Heysham 2

Torness

2000 2010

Sizewell B 2005 2015

Historic PSRs – 2nd Round of PSRs

2005-2015

0

100

200

300

400

500

600

EDF Energy Findings

ONR Findings

Transition of PSR structure (NPPs only)

• Initially the PSR structure took on the form of “Main

Reviews” supported by “Discipline Reviews”

• The reviews sat in Chapters of the PSR; chapter 1 always

being the headline safety justification

• The process has matured and become more efficient for

both Licensee and ONR as the second round of PSRs

took place across the plants

• IAEA guidance (SSG-25) published in 2013 will form

the basis of the PSR3 work

PSR3 Structure

NSC

Paper

Dynamic

ALARP

PSR3

Stand

Back

Review

Summary

Document

on Plant

Design

Summary

Document

on Safety

Analysis

Summary

Document

on Safety

Performance

Safety

Factor 1

Plant

Design

Safety

Factor 2

Actual

Condition of

Safety

Related

Plant

Safety

Factor 3

Equipment

Qualification

Safety

Factor 4

Ageing and

Lifetime

Management

Safety

Factor 5

Deterministic

Safety

Analysis

Safety

Factor 6

Probabilistic

Safety

Analysis

Safety

Factor 7

Hazard

Analysis

Safety

Factor 8

Safety

Performance

Safety

Factor 9

Experience

from other

Plants &

Research

Safety

Factor 10

Organisation,

Management

Systems and

Safety Culture

Safety

Factor 11

Procedures

Safety

Factor 12

Human

Factors

Safety

Factor 13

Emergency

Planning

Safety

Factor 14

Radiological

Impact on

the

Environment

Safety

Factor 15

Radiological

Protection

Safety

Factor 16

Decommissioning

Additional Safety Factor report

following advice from NSC to cover

decommissioning phase

EDF documents that align with the

IAEA Safety Factors documents and

focus on the company process

management information supporting

the review area.

Upcoming PSR3s

Station PSR3 Submission Date ONR Decision Date

Hinkley Point B

Hunterston B

January 2016 January 2017

Dungeness B January 2017 January 2018

Heysham 1

Hartlepool

January 2018 January 2019

Heysham 2

Torness

January 2019 January 2020

Sizewell B January 2024 January 2025

Wylfa

• Wylfa is the last remaining Magnox reactor

and is due to cease operation by

December 2015

• Wylfa completed the most recent PSR in

September 2014 (decision date)

• Next PSR due 2023/4

• ONR considered the stage Wylfa was

at in the lifecycle, future submissions

that would cover defuelling,

decommissioning

Conclusions

• The UK regulator and licensees has a

mature process for undertaking PSRs

• The process has evolved over the past 20

years and the UK NPP fleet is currently

about to undertake the third round of PSRs

• Learning from recent PSRs will continue

to be applied to the AGRs as they

commence the third round of PSRs