MULTINATIONAL DESIGNEVALUATION PROGRAMME
Annual Report
April 2019-June 2021

Multinational Design Evaluation
Programme
Annual Report
April 2019-June 2021

FOREWORD FROM THE POLICY GROUP CHAIR

Foreword from the Policy Group Chair

It has been a pleasure and an important responsibility to serve the Multinational Design
Evaluation Programme (MDEP) as Policy Group Chair. MDEP is a unique multinational
initiative leveraging the resources and knowledge of national regulators to review newreactor designs, an initiative that has been widely recognised as an effective framework
for regulatory co-operation and harmonisation.
The MDEP Policy Group decided to “sunset” MDEP in its current form by the end of 2021
and it agreed that a new streamlined governance structure should be implemented for
MDEP in 2022, with a framework much more suited to the smaller number of reactor
technologies that will participate in MDEP in the future. The past two years have been atransition period for MDEP, and to that end this report will encompass all MDEP activities
from April 2019 to June 2021.
Since early 2020 the global environment that we had all been operating in fundamentally changed due to the
COVID-19 pandemic. However, thanks to the support and engagement of our members, we made great progressin several areas during the last two years despite the restrictions imposed on in-person interactions. Notably,
the challenges in addressing hydrogen recombiners’ reliability and effectiveness during the plant life have been
discussed by all current Design-Specific Working Groups (DSWGs) and each working group has published atechnical report on hydrogen management to establish a common understanding of the regulatory requirements
between the national regulatory bodies of MDEP members.
In addition, as national regulators adjusted their vendor inspection programmes with enhanced use of
remote inspection, the impact and learning from the COVID-19 response have been shared more widely as
part of country-specific updates in the Vendor Inspection Cooperation Working Group (VICWG) meetings. The
working group also trialled the delivery of a remote Multinational Vendor Inspection. This was successfullycompleted and represents a further example of efficient and effective regulatory co-operation that can be
adopted more widely in the future.
The ability to maintain momentum, despite the difficult conditions, emphasises the importance of thestrong relationships and communication routes established as part of MDEP pre-pandemic, which meant it
has been quick and easy to communicate with colleagues from other regulators when issues arise.
We have made great steps towards the transition of MDEP to a more simplified governance framework.
The details of the new framework have been agreed by the members of the future framework. We have createda transition team to focus on the activities required for a smooth transition. We have been working on a rangeof close-out activities, necessary knowledge management efforts, and the development of closure reports andother ongoing activities to achieve an orderly shutdown of the MDEP framework 2006-2021.
An overarching close-out report for MDEP 2006-2021 has been produced that draws together the work of
MDEP during this period and provides a clear reference to all of the key MDEP documentation and reports thatwill be available for the future use of MDEP members in the MDEP Library, which will be maintained by the
Nuclear Energy Agency (NEA) Secretariat.
The 5th MDEP Conference has been postponed to 2022 due to the global impact of COVID-19. It is anticipatedthat the conference can go ahead during the latter part of 2022, utilising the initial programme developed by
the MDEP Steering Technical Committee (STC), but the detailed arrangements for the conference will now
need to be developed under the new framework. Hopefully, we can gather all MDEP members as well as wider
MDEP stakeholders at this event, to hear about the great co-operation and excellent work completed under
the current framework and look to the future and the benefits that can be delivered under the new one.
Please stay safe and well in these difficult times.
Mark Foy
MDEP Policy Group Chair

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TABLE OF CONTENTS

Table of contents

Executive summary............................................................................................................................... 7
1. Introduction ........................................................................................................................................ 9
2. Programme goals and outcomes .................................................................................................. 11
3. Programme implementation ......................................................................................................... 13
3.1 Membership .............................................................................................................................. 13
3.2 Organisational structure ......................................................................................................... 13
3.3 MDEP Library............................................................................................................................. 14
3.4 Common Positions ................................................................................................................... 15
4. Interactions with other organisations ......................................................................................... 17
4.1 NEA Committee on Nuclear Regulatory Activities (CNRA) ................................................ 17
4.2 International Atomic Energy Agency (IAEA) ........................................................................ 18
4.3 Industry ..................................................................................................................................... 18
4.4 World Nuclear Association ..................................................................................................... 18
5. Current activities ............................................................................................................................. 21
5.1 EPR Working Group (EPRWG) ................................................................................................. 22
5.2 AP1000 Working Group (AP1000WG) ..................................................................................... 24
5.3 APR1400 Working Group (APR1400WG) ................................................................................ 24
5.4 VVER Working Group (VVERWG) ........................................................................................... 26
5.5 HPR1000 Working Group (HPR1000WG) ................................................................................ 26
5.6 Vendor Inspection Co-operation Working Group (VICWG) ............................................... 28
6. Interim results ................................................................................................................................. 31
7. Next steps – Future of the programme........................................................................................ 33
Appendix 1: List of abbreviations and acronyms.......................................................................... 35
Appendix 2: Revised or new documents and publications ......................................................... 37

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EXECUTIVE SUMMARY

Executive summary

The Multinational Design Evaluation Programme (MDEP) aims to leverage the resources and knowledge ofnational regulatory authorities that are currently, or will shortly be, undertaking the review of new reactor power
plant designs. MDEP members are the regulatory authorities of Argentina (Nuclear Regulatory Authority, ARN),
Canada (Canadian Nuclear Safety Commission, CNSC), the People’s Republic of China (National Nuclear Safety
Administration, NNSA), Finland (Radiation and Nuclear Safety Authority, STUK), France (French Nuclear Safety
Authority, ASN), Hungary (Hungarian Atomic Energy Authority, HAEA), India (Atomic Energy Regulatory Board,
AERB), Japan (Nuclear Regulation Authority, NRA), Korea (Nuclear Safety and Security Commission, NSSC), Russia(Rostechnadzor), South Africa (National Nuclear Regulator, NNR), Türkiye (Turkish Atomic Energy Authority,
TAEK), the United Arab Emirates (Federal Authority for Nuclear Regulation, FANR), the United Kingdom (Officefor Nuclear Regulation, ONR) and the United States (Nuclear Regulatory Commission, NRC). The OECD Nuclear
Energy Agency (NEA) performs the Technical Secretariat function in support of MDEP. The International Atomic
Energy Agency (IAEA) also takes part in the work of MDEP. This programme incorporates a broad range ofactivities including enhancing multilateral co-operation within existing regulatory frameworks and increasing
multinational convergence of codes, standards, guides and safety goals. A key concept throughout the work of
MDEP is that national regulators retain sovereign authority for all licensing and regulatory decisions.
According to the Policy Group’s decision made in October 2020, MDEP is moving forward with plans to close
the EPR Working Group, AP1000 Working Group, and APR1400 Working Group by the end of 2021, and a new
MDEP governance structure will be implemented in 2022. Although MDEP is in a period of transition, working
groups continued to share information and experience on the safety design reviews with the purpose ofenhancing the safety of the design and enabling regulators to make timely licensing decisions. This annual
report encompasses all MDEP activities from April 2019 to June 2021.
Substantial progress has been made on the overall MDEP goals of increasing co-operation and convergenceof requirements and practices. In addition, the lessons learnt from the 11 March 2011 accident at the
Fukushima Daiichi Nuclear Power Plant have been addressed appropriately by all designs under MDEP andincorporated into MDEP activities in the Design-Specific Working Group (DSWG) programme plans.
Accomplishments to date provide confidence that the MDEP membership, structure and processes offer an
efficient method of co-operating in regulatory reviews for new designs. At the level of the working groups, thekey accomplishments for April 2019-June 2021 include:•

The EPR Working Group published Technical Reports on Hydrogen Management for EPR (TR-EPRWG-06),
and an EPR Assessment of 2A Large Break Loss-of-Coolant Accident (2A-LOCA) Analysis (TR-EPRWG-07).
It also published updated Common Positions on the EPR Instrumentation and Controls Design(TR-EPRWG-01).

•

The AP1000 Working Group published the Technical Reports: Hydrogen Control System for the AP1000
Design (TR-AP1000WG-04), Lessons Learnt from Implementation of the Common Position on FPOT for
AP1000 (TR-AP1000WG-05), and Hot Functional and Startup Testing Lessons Learnt (TR-AP1000WG-06).
It also finalised a Technical Report on AP1000 Technical Exchanges during the Design, Construction, andCommissioning of AP1000 Reactors, which is restricted to AP1000WG members at the request of themembers.

•

The APR1400 Working Group continued to exchange information on country-specific design issues in
Korea, the United Arab Emirates, and the United States. It published the Common Position
CP-APR1400-04: Irradiation Effect on the APR1400 Fuel Bundle Spacer Grid Strength. The working groupalso published the Technical Reports: Hydrogen Recombiner Survey Results for APR1400 design andComparison of the Regulatory Requirements for Probabilistic Risk Assessment (PRA).

•

The VVER Working Group completed a Common Position (CP-VVERWG-02) on Addressing Ex-vessel
Corium Stabilization in Core Catcher. It published the Technical Reports: Regulatory Approaches Related
to Accidents and Transients Analyses (TR-VVERWG-03), Core Catcher (TR-VVERWG-04), and Hydrogen
Recombiners (TR-VVERWG-05). It also finalised a draft of the Common Position: Reactor Pressure Vessel

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2019-2021 MDEP ANNUAL REPORTand Primary Components Reliability for AES-2006 designs. The working group also continues to develop
two technical reports on similarities and differences among the VVER designs VVER-1000 and VVER1200.

8•The HPR1000 Working Group published the Common Position CP-HPR1000WG-01: Addressing
Fukushima Daiichi Nuclear Power Plant Accident-Related Issues. It also published the Technical Reports:
Hydrogen Control During Severe Accidents (TR-HPR1000WG-01) and Regulatory Requirements andPractices for Severe Accidents (TR-HPR1000WG-02). The working group is now developing Common
Positions on the Vienna Declaration on Nuclear Safety, and Sump Strainer Performance. The HPR1000
Severe Accidents TESG is developing a Common Position on Addressing In-Vessel Retention Strategy,
and the Internal and External Hazards TESG is finalising a Technical Report on HPR1000 Hazards.

•

The Vendor Inspection Co-operation Working Group (VICWG) published a Technical Report on Safety
Culture in the Nuclear Supply Chain (TR-VICWG-07). It finalised the Technical Report: Assessment ofMultinational Vendor Inspection of ENSA (Spain) (TR-VICWG-06) which is restricted to VICWG members
at the request of the members. The VICWG updated two Common Positions (CP-VICWG-02 and
CP-VICWG-04): Witnessed, Joint and Multinational Vendor Inspection Protocol; and Mitigating the Risks
of Counterfeit, Fraudulent, and Suspect Items. The VICWG conducted the 3rd and 4th Multinational
Vendor Inspection in 2019 and 2021, respectively.

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INTRODUCTION

1. Introduction

The Multinational Design Evaluation Programme (MDEP) develops innovative approaches to leverage theresources and knowledge of national regulatory authorities who are, or will shortly be, reviewing new reactor
power plant designs. MDEP is primarily focused on design evaluation, but also includes inspection activities andgeneric issues. A key concept throughout the programme is that MDEP will better inform the decisions ofregulatory authorities through multinational co-operation, while each regulator retains the sovereign authority
to make licensing and regulatory decisions.
Working groups are implementing the activities in accordance with their programmes, and haveestablished the necessary interfaces both within and outside MDEP members. Although MDEP is in a periodof transition to a new framework, significant progress has been made over the past two years on the overall
MDEP goals of increased co-operation and convergence of requirements and practices. Accomplishments todate provide confidence that the MDEP membership, structure and processes provide an effective method of
increasing co-operation in regulatory design reviews for new reactors.
MDEP was established in 2006 as a multinational initiative for a five-year period. It was extended for anotherfive-year period in 2012 by the MDEP Policy Group, which oversees MDEP operations, based on the value gainedby the members. In 2015, the Policy Group determined that MDEP should continue in its current form, for at least
five more years following 2017. The Policy Group recommended and the NEA Committee on Nuclear Regulatory
Activities (CNRA) agreed to transfer of two of the issue-specific working groups (Codes and Standards Working
Group [CSWG] and Digital Instrumentation & Control [DI&C] Working Group) and one design-specific working
group (Advanced Boiling Water Reactor Working Group) to the CNRA. In September 2019, the Policy Groupdecided to sunset MDEP in its current form by 2022 and affirmed that ongoing work on VVER and HPR1000 should
continue. A slimmer MDEP structure has been established for this work in 2022 and beyond. In October 2020, thePolicy Group approved moving forward with plans for the closure of the EPR Working Group, AP1000 Working
Group, and APR1400 Working Group by the end of 2021, and determined that a new MDEP governance structure
would be implemented in 2022. This annual report encompasses all MDEP activities from April 2019 to June 2021.

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PROGRAMME GOALS AND OUTCOMES

2. Programme goals and outcomes

The main objectives of the Multinational Design Evaluation Programme (MDEP) effort are to enable increased
co-operation within existing regulatory frameworks and establish mutually agreed upon practices to enhance
the safety of new reactor designs. The enhanced co­operation among regulators will improve the effectivenessand efficiency of the regulatory design reviews, which are part of each country’s licensing process. The
programme focuses on co-operation on regulatory practices that aim at harmonising regulatory requirements.
The International Atomic Energy Agency (IAEA) safety standards, which provide a general level of harmonisation,
provide input to the work and can benefit from the final results.
MDEP is meeting its goal of enabling increased co-operation through the activities of the working groups.
MDEP has been successful in providing a forum for regulatory bodies to co-operate on design evaluations andinspections. In addition to organising working groups, MDEP has provided each regulator with peer contacts
who share information, discuss issues informally and disseminate information rapidly. For example, theDesign-Specific Working Group (DSWG) members have benefitted significantly from the sharing of questions
among the regulators, resulting in more informed and harmonised regulatory decisions. MDEP interactions
are useful in confirming findings that had previously been made. It also improved the safety focus of thedesign review, and helped identify previously undiscovered safety issues or expanded the scope of review.
MDEP members have also been highly successful in co-ordinating vendor inspections during which theregulators share observations and insights. MDEP has made improvements in communicating information
regarding the members’ regulatory practices through development of an MDEP Library which serves as acentral repository for all documents associated with the programme. Moreover, successful interactions withstakeholders via MDEP have built links with regulators, industry, standard development organisations (SDOs)
and other international organisations, and have been beneficial in reviewing different reactor designs.

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PROGRAMME IMPLEMENTATION

3. Programme implementation

3.1 Membership
Participation in the Policy Group and Steering Technical Committee is intended for national safety authorities ofinterested countries that already have commitments for new build or firm plans to have commitments in thenear future for new reactor designs. The Multinational Design Evaluation Programme (MDEP) current members
are: Argentina, Canada, China, Finland, France, Hungary, India, Japan, Korea, Russia, South Africa, Türkiye, theUnited Arab Emirates, the United Kingdom and the United States. The International Atomic Energy Agency (IAEA)
also takes part in the work of MDEP.

3.2 Organisational structure
The programme is governed by a Policy Group (PG), made up of the heads of the participating organisations,and implemented by a Steering Technical Committee (STC) and its working groups. The STC consists of seniorstaff representatives from each of the participating national safety authorities in addition to a representativefrom the IAEA.
The Policy Group provides guidance to the Steering Technical Committee on the overall focus of MDEP,
monitors the progress of the programme, and determines participation in the programme.
The STC manages and approves the detailed programme of work, including: defining topics and working
methods; establishing technical working groups and the nomination of experts; approving procedures andtechnical papers developed by the working groups; establishing interfaces with other international efforts tobenefit from available work and avoid duplication; developing procedures for the handling of information to
be shared in the project; reporting to the PG; identifying new topics for the programme to address; andestablishing subcommittees of the STC to study specific topics.
The Nuclear Energy Agency (NEA) performs the Technical Secretariat function in support of MDEP.
Two lines of activities have been established to carry out the work of MDEP:•

Design-specific activities: Design-specific working groups share information on a timely basis andco­operate on the areas of specific reactor design evaluations, construction oversight and thecommissioning and early phase operation of new reactors. Participants in these working groups are theregulatory authorities that are actively reviewing, preparing to review, or regulating the construction of
the specific new reactor designs. A Design-Specific Working Group (DSWGs) is formed when three ormore MDEP member countries express interest in working together. Under the Design-Specific Working
Groups, expert subgroups have been formed to address specific technical issues. Non-MDEP regulators
could request MDEP membership in order to join a DSWG.

•

Issue-specific activities: Working groups may also address specific technical and regulatory processareas within the programme of work. MDEP has one issue-specific working group addressing vendor
inspection issues (VICWG); it previously incorporated working groups on codes and standards (CSWG)
and digital instrumentation and controls (DICWG). Membership in issue-specific working groups is open
to all MDEP participating countries and the IAEA representatives. These topics were chosen because theactivities are of general interest and of safety significance to the licensing of new reactors in MDEP
member countries. The approaches followed by the MDEP regulators are not completely alike, andsuccessful completion of the activities related to the issue-specific working groups will likely result inincreased harmonisation and convergence in regulatory practices or increased co-operation. In June 2015,
the MDEP PG determined that the programme should focus on design-specific activities going forward
and the issue-specific working groups should be closed or transferred to another organisation over the
next few years. The Digital I&C and Codes and Standards working groups were transferred to the CNRA
in 2017 and 2018, respectively. The official transition of VICWG is expected in 2023. The following chart
illustrates how the programme is currently organised.

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2019-2021 MDEP ANNUAL REPORT

Figure 3.1: MDEP organisational structure as of June 2021

3.3 MDEP Library
In part, MDEP information is communicated among the members through the MDEP Library, which serves as acentral repository for all documents associated with the programme. The NEA provides the technical support fordevelopment and maintenance of the MDEP Library on a secured password-protected website. The website
provides two levels of access which are: 1) general access open to every member, and 2) restricted area accessfor each MDEP working group’s member regulators participating in that specific group. Publicly available
documents related to MDEP are available on the MDEP page of the NEA website (www.oecd-nea.org/mdep). The
STC, through the secretariat, maintains the library and makes enhancements to improve its effectiveness.
In order for MDEP to be successful in fulfilling its goal of leveraging the work of peer regulators in theevaluation of new nuclear power plant designs, a framework was developed to facilitate the sharing of technicalinformation among MDEP participants which at times may include the sharing of proprietary and other types ofsensitive information. As a general rule, the information exchanged as part of MDEP in meetings and the MDEP
Library is for the sole use of the participating national regulatory authorities. The members of the working groups
also follow the communications protocol to share new information related to new reactors with other members
in advance of its release to the public. A large portion of the information shared may not be proprietary or
sensitive; however, all participating members must protect and properly handle the information that an
originator claims to be proprietary or sensitive.
The MDEP Library will continue to be a central repository for future frameworks of MDEP. When and if
additional countries are admitted to MDEP, they shall have access to the library and shall abide by all relevant
guidance and rules, including the protection and proper handling of proprietary and sensitive information
contained in the library.

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PROGRAMME IMPLEMENTATION

3.4 Common Positions
MDEP has developed a process for identifying and documenting Common Positions on specific issues among themember regulators based on existing standards, national regulatory guidance, best practices and group member
inputs. Design-specific Common Positions document common conclusions that the working group members
have reached during design reviews. Discussions among the members and the sharing of information in theseareas help strengthen the individual conclusions reached.
Generic Common Positions apply generically rather than only to one specific design. Generic Common
Positions document practices and positions that each of the working group members find acceptable. The
Common Positions are intended to provide guidance to the regulators in reviewing new or unique areas, andwill be shared with the IAEA and other standards organisations for consideration in standards development
programmes. After a Common Position is agreed to by a working group, it is presented to the STC for
endorsement. Upon endorsement by the STC, the proposed Common Positions are made publicly available on
the NEA MDEP website in order to keep external stakeholders informed of the work completed within MDEP.
Those Common Positions will become commendable practices, recommended by MDEP. There is no obligationon the part of any regulatory body to follow them. A key concept throughout the work of MDEP is that national
regulators retain sovereign authority for all licensing and regulatory decisions. If a regulatory body chooses toformally adopt a Common Position, it would be through that country’s regular processes.

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INTERACTIONS WITH OTHER ORGANISATIONS

4. Interactions with other organisations

The Multinational Design Evaluation Programme (MDEP) strives to maintain an awareness of, and interactions
with, other organisations that are implementing programmes to facilitate international co-operation on newreactors. Interactions focus on ensuring that MDEP does not duplicate efforts and benefits from the outputsof these organisations.
A key outcome of MDEP’s co-operation with external organisations was the MDEP Conferences. MDEP hasorganised four conferences, and these events provided a forum for MDEP stakeholders (including industry
representatives, standard development organisations and other international organisations) to share theresults of their engagement with the programme and to deliver presentations on ongoing activities related to
new reactor licensing. The 5th MDEP Conference was initially scheduled for October 2020, but was postponed
to 2022 due to COVID-19 restrictions.

4.1 NEA Committee on Nuclear Regulatory Activities (CNRA)
The CNRA Working Group on the Regulation of New Reactors (WGRNR) examines the regulatory issues of siting,licensing, and regulatory oversight of Generation III+ and Generation IV nuclear reactors. The current focus areasof the WGRNR are construction experience and construction inspection issues. The WGRNR co-ordinates its
work with the work performed by MDEP such that it utilises its outputs, does not duplicate its efforts, andextends the results of MDEP to other CNRA members. To avoid overlap of activities between the groups, the
WGRNR focuses on procedures and guidance, while MDEP focuses on design-specific issues.
MDEP interacts with the CNRA WGRNR and the Working Group on Inspection Practices (WGIP) through the
NEA, which also serves as the Technical Secretariat for the CNRA. The WGRNR is the focal point of interactions
between MDEP and the CNRA and its working groups, and will assist in co-ordinating communications andrequests between the two activities in order to ensure that the MDEP’s efforts take full advantage of the work
already being done by the CNRA.
The Proceedings of the 2018 Committee on Nuclear Regulatory Activities/MDEP Workshop on Nuclear Supply
Chain Management was published in November 2019. The recommendations and conclusions served to informongoing activities of the MDEP VICWG and provide the basis for the CNRA to decide on future activities or tasks.
Enhanced stakeholder engagement in particular has been considered and prioritised by the VICWG.
In 2019, a teleconference was held to consider the WGRNR’s programme scope on supply chain regulatory
oversight. After discussion, the WGRNR will focus on the regulation of major project contracting models. The
WGRNR and VICWG agreed to collaborate going forward to avoid potential duplication on regulation of supply
chain. The VICWG also co-ordinated with the WGRNR on a survey of the oversight of suppliers at construction
sites.
To consider the COVID-19 impacts on vendor inspection practice and the risks and opportunities, a joint
workshop was held virtually by the CNRA WGIP and the Working Group on Human and Organisational Factors(WGHOF) and the MDEP VICWG on 24-25 February 2021. The draft output was shared with the participants
and will be utilised to inform the WGIP 2022 workshop. Additionally, the VICWG has been supporting the
CNRA Working Group on Digital Instrumentation & Controls (WGDIC) in considering how existing vendor
inspection processes could be applied to support Digital I&C Vendor Inspections. The VICWG also supported
the joint WGDIC and WGIP “Special International Nuclear Regulatory Inspection Workshop on Digital
Instrumentation & Control (DI&C)” held in Toronto, Canada, in June 2019. Moreover, the CNRA Working Groupon Safety Culture (WGSC) and the VICWG have been collaborating on safety culture in the supply chain.
In accordance with the PG direction to transfer the MDEP issue-specific working group activities to the NEA,MDEP has co-operated with CNRA leadership to undertake the transfer of additional activities to the CNRA.
The benefits of continuing co-ordination among regulators on these topics have been recognised both within
and outside of MDEP.

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2019-2021 MDEP ANNUAL REPORTIn 2020, the PG decided to transfer the VICWG to the CNRA. VICWG activities will close under the current
MDEP framework at the end of 2021. During 2022, the VICWG will be working with the CNRA under the NEA
auspices on the process of transition, with the official transition expected in 2023 when the CNRA starts a new
structure. In addition, MDEP is currently working with the CNRA to transfer the EPRWG activities, as the EPRWG
members have identified additional work related to operating reactors that is beyond the MDEP framework.

4.2 International Atomic Energy Agency (IAEA)
The IAEA takes part in the work of MDEP through participation in the PG, STC and issue-specific working groupmeetings. In addition, the generic Common Positions developed in MDEP are shared with the IAEA for
consideration in the IAEA standards development programme.
As the IAEA is developing a Technical Document (TECDOC) on the acceptance process for using commercial
grade items in nuclear power plant safety systems, the VICWG discussed their approach to provide input forthe document, i.e. develop the regulatory perspective and Common Positions on the acceptance process forusing commercial grade products in nuclear power plant safety systems.

4.3 Industry
The MDEP working groups are interested in understanding the perspectives of the design vendors, codes andstandards organisations, component manufacturers and the challenges they face in dealing with numerous
regulators and regulatory systems. The MDEP working groups interact with industry groups and invite them toparticipate in selective portions of meetings and other activities. For example:•

The EPR Working Group meets regularly with representatives of Framatome, EDF and other EPR licensees,
applicants and potential applicants to discuss similarities and differences among the EPR designs being
licensed in each country.

••

The AP1000 Working Group meets with Westinghouse and the AP1000 applicants and licensees.

•

The VVER Working Group continues to interact with the Russian nuclear industry, as well as invited
representatives of Rosatom, Rosenergoatom and design organisations (such as Atomenergoproekt,
Atomproekt, and Gidropress) to take part in the meetings of the VVERWG and its subgroups to acquire
additional information about safety-significant design solutions.

•

The HPR1000 Working Group meets with Hualong Nuclear Power Technology Co., Ltd and the HPR1000
licensees in China.

•

The Vendor Inspection Co-operation Working Group (VICWG) meets with SDOs and the World Nuclear
Association (WNA).

The APR1400 Working Group meets with KHNP and representatives of the licensee for the Barakah
nuclear power plant, an APR1400 in the United Arab Emirates.

4.4 World Nuclear Association
The World Nuclear Association’s Working Group on Cooperation in Reactor Design Evaluation and Licencing(CORDEL) acts as the industry counterpart to MDEP. Since both MDEP and CORDEL have expressed interest in
and have established a goal of furthering harmonisation of reactor designs, regulatory practices, and industry
and international standards, the MDEP PG has agreed that co-ordination of efforts with CORDEL is appropriate
in some cases. While co-ordinating efforts in areas of mutual interest, MDEP members will always retain theirindividual and independent regulatory roles and positions. Members of the MDEP STC meet with CORDEL
periodically, and CORDEL has participated in meetings of the MDEP VICWG.
While MDEP is a regulatory forum and CORDEL is an industry organisation, both parties agree they canbenefit from communications and co­operation where the organisations share common goals. Both MDEP
and CORDEL maintain strong interests in the harmonisation of new reactor designs and design reviews,
regulatory safety standards and practices, and related industry and IAEA standards. MDEP values continued
interaction to assist in achieving these goals while each organisation functions in a manner consistent with
its appropriate roles and responsibilities.

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INTERACTIONS WITH OTHER ORGANISATIONSThe WNA’s Supply Chain Working Group is tied closely to CORDEL. During the reporting period, a WNA
representative from the Supply Chain Working Group was invited to provide presentations on the activities ofinterest to the VICWG. The VICWG agreed to continue regular interactions with the WNA’s Supply Chain
Working Group in the future.

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CURRENT ACTIVITIES

5. Current activities

The activities of MDEP are being implemented through design-specific and issue-specific working groups. The
members of the Design-Specific Working Groups share information and co-operate on specific reactor design
evaluations and construction oversight. MDEP also maintains one issue-specific working group that scrutinises
technical and regulatory process areas within the programme of work. Each working group has a lead andco-lead regulator designated as chair and vice chair, and has developed a programme plan which identifies
specific activities, schedules and contacts.
The Design-Specific Working Groups leverage national regulatory resources by sharing information andexperience on the regulatory safety design reviews with the purposes of enhancing the safety of the design andenabling regulators to make timely licensing decisions. Design-specific working groups achieve this goal through:•Exchanging experiences and lessons learnt on licensing process implementation, design reviews, anddesign-related construction and commissioning activities.

•

Working to understand the differences in regulatory safety review approaches in each country tosupport potential use of other regulators’ safety design evaluations, where appropriate.

•

Identifying and understanding key design differences, including those originating from regulatory
requirements, and then documenting the reasons for differences in regulatory requirements.

•

Looking for opportunities to provide input to issue-specific working groups on potential topics ofsignificant interest.

•

Documenting common MDEP positions on aspects of a review.

•

Documenting the group’s activities in Technical Reports to ensure knowledge transfer.

•

Communicating and co-ordinating communications on MDEP views and Common Positions tovendors and operators regarding the basis of safety evaluations and standardisation.

While the Design-Specific Working Groups typically address issues that the members find challenging,specific to each design, some topics are addressed by several working groups, for instance commissioning
activities, the Fukushima Daiichi lessons learnt, and hydrogen management.

Commissioning activities
Members of Design-Specific Working Groups, especially EPRWG and AP1000WG, are presently devoting
resources for co-operation on commissioning of first-of-a-kind (FOAK) reactor testing. Lessons learnt by MDEP
will be transferred to the WGRNR for it to pursue the work on a generic basis, with participation open to awider range of regulators.
The MDEP generic Common Position addressing first plant only tests (FPOT) provides high-level guidance
to applicants and licensees that wish to take credit for a FPOT performed during the commissioning of thefirst unit of a similar type, if accepted by the applicants, licensees and regulators. An FPOT allows a test
performed on the very first reactor of a specific design to be credited for the subsequent units of similar design.

•

As China AP1000s have moved into the commissioning phase, the Commissioning Activities TechnicalExpert Subgroup (TESG) shared information on commissioning tests, significant issues related to thetesting, and lessons learnt on pre-operational testing. The TESG increased co-operation on AP1000 hot
functional testing lessons learnt from the Sanmen, Haiyang, and Vogtle sites, and on pre-operationaland startup testing as more reactors start going through these phases. In May 2021, these efforts
culminated with the publication of the Technical Reports: Hot Functional and Startup Testing Lessons
Learnt (TR-AP1000WG-06) and Lessons Learnt from Implementation of the Common Position on FPOT
for AP1000 (TR-AP1000WG-05).

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Fukushima Daiichi Nuclear Power Plant accident lessons learnt
Lessons learnt from the Fukushima Daiichi Nuclear Power Plant accident have been discussed by all of the
DSWGs and each working group has developed a Common Position that identifies common approaches toaddress potential safety improvements, as well as common general expectations for new nuclear power plants.
As directed by the MDEP PG, the STC and working groups developed an integrated MDEP Common Position on
the lessons learnt from the Fukushima Daiichi Nuclear Power Plant accident. The STC finalised this document
in 2016 and placed it on the MDEP public web page. MDEP recognises that other related international initiatives
have been implemented that are focused on operating plants. Therefore, it is important for new MDEP designs,
such as the HPR1000, to address the Fukushima Daiichi lessons learnt. In November 2020, the HPR1000
Working Group finalised a Common Position addressing Fukushima Daiichi Nuclear Power Plant accidentrelated issues, which supplements the MDEP Common Position developed by the STC.

Hydrogen management
The challenges in addressing hydrogen recombiners’ reliability and effectiveness during the plant life have been
discussed by all current DSWGs (EPR, AP1000, APR1400, VVER and HPR1000 DSWGs) and each working group has
published a technical report on hydrogen management to identify a common understanding of the regulatory
requirements of the member regulators. These were follow-up efforts from the 2016 Severe Accident TESGs
workshop.

MDEP co-operation in operational phases
MDEP was established primarily as a forum to co-operate on design reviews. As the designs are moving into
the commissioning and eventually the operational phases, the PG and STC have discussed the benefits andchallenges of continuing co-operation after construction is complete and into the operational stages. MDEP
recognises the benefits of continuing the co-operative relationships formed during the design review stage,
as well as the benefit to the members of the Design-Specific Working Groups (DSWG) who are still in thelicensing phase. The PG has determined that the operational stage should not be included in the scope of
MDEP. However, they stated there should be a means to ensure that operating experience related to design
issues is addressed by DSWGs. With this in mind, MDEP will continue to share information on construction
and commissioning of new reactors, and incorporate feedback from operating experience as it pertains todesign.
MDEP members agree that operating experience, when it has an impact on designs, should be considered.
In particular, information from the first two years of operation may be directly related to commissioning.
MDEP members are encouraged to stay and participate in a group after the considered reactor begins tooperate in their country to share operating experience.
This issue was raised once more at the STC meeting in June 2017. After an extensive discussion, it was
clear that the members value the forum that MDEP provides. The discussion revolved mostly around thetransition of a DSWG from MDEP to another area because there is a real value in the structured co­operationand dialogue that MDEP promotes. The STC discussed this challenge extensively and it is considering the
Policy Group’s guidance following their September 2017 meeting. The ABWRWG was the first design working
group in MDEP to complete its programme of work and ceased its activities under MDEP in June 2018.
In 2020, the programmes of work for the EPR, AP1000 and APR1400 DSWGs are mostly focused on lessons
from commissioning and early phase operation activities and these DSWGs are expected to complete theirplanned activities by 2022. At its October 2020 meeting, the PG approved moving forward with plans for closureof the EPR, AP1000, and APR1400 DSWGs by the end of 2021. The PG also decided that operating experience ofa new design beyond two years of initial operation will not be considered within the scope of MDEP.

5.1 EPR Working Group (EPRWG)
The EPR DSWG includes the regulatory authorities of China (NNSA), Finland (STUK), France (ASN), India (AERB),
and the United Kingdom (ONR). By leaving MDEP in 2020, Sweden (SSM) also left the EPRWG. Other members
acknowledged their precious contribution and active participation.

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Numerous meetings and technical exchanges have taken place to share information on the reviews being
conducted in each country. Several major construction activities are ongoing: Olkiluoto 3 in Finland andFlamanville 3 in France are in late stages of commissioning. The twin unit plant at Hinkley Point C in the
United Kingdom is in the early construction phase. The first of the two Taishan (China) units enteredcommercial operation in December 2018. The second unit followed in September 2019.
The EPR Working Group currently includes five technical expert subgroups (TESG) that are addressing
information on specific technical issues: Accidents and Transients (A&T TESG), Digital Instrumentation andControl (DI&C TESG), Probabilistic Safety Assessment (PSA TESG), Severe Accidents (SA TESG) andCommissioning Activities (CA TESG). With the exception of the CA TESG, the expert subgroups reduced thefrequency of meetings over 2019-2020, having the main objective to complete their programme of work andto develop their contribution for the EPRWG closure report. From 2021 there will only be the CA TESG. Besides,
considering the situation of the EPRWG and the status of the projects, it was decided to merge CA TESG and
EPRWG discussions gradually over 2021.
The EPRWG meets occasionally with representatives of Framatome and of EPR licensees, applicants, andpotential applicants to discuss similarities and differences among the EPR designs being reviewed and licensed
in each country. In June 2018, the EPRWG held a meeting in Bristol, United Kingdom, which included a visit to
Hinkley Point C. In November 2018, the EPRWG met in Zhuhai, China, before visiting the Taishan plant. The
EPRWG held a joint meeting in May 2019 with the EPR OOG (Operators Owners Group) to discuss various topics
with the licensees and Framatome, including the early lessons learnt from the Taishan Unit 1 operations.
In addition to the May 2019 meeting, the EPRWG met once in Boulogne-Billancourt, France. Due to thespecial circumstances in 2020 and 2021, the EPRWG met remotely (twice in 2020, three times in 2021).
Considering the two EPR units in Taishan are in operation and the reactors in Finland and France are close
to being completed, it was decided to sunset the EPRWG within MDEP at the end of 2021. The working groupwill focus its effort on completing its programme of work and on developing its closure report.

Accomplishments and plan of work
In 2018, the EPRWG completed and published a Common Position stating how the EPR design addresses theobjectives of the Vienna Declaration, especially with regards to avoiding large and early releases and longterm contamination. This Common Position addresses design basis, design extension and severe accidents.
Given the move of most of the current EPR projects towards final commissioning and operation, a review ofthe plan of work and TESGs was undertaken, with most TESGs anticipated to complete their programme of workand close by the end of 2020.
The Probabilistic Safety Assessment (PSA) TESG mainly worked on developing its contribution for the closure
report after having published a technical report identifying the main differences in the modelling of a numberof reactor faults in the various EPR designs.
The Accidents and Transients (A&T) TESG has been discussing reactor physics data obtained from the postfuel load commissioning tests at Taishan and various aspects of the EPR design, including the effectiveness ofthe pump filtration in design basis and severe accidents, and Heating, Ventilation and Air Conditioning (HVAC)
designs. They have developed a Common Position on boron dilution issues. In addition, the subgroup hascompleted a paper on double-ended guillotine break loss of cooling accidents (2A LOCA).
The Digital Instrumentation and Controls (DI&C) TESG has developed a Common Position in EPR I&C designs.
The paper was released in 2020. A technical report on EPR I&C designs is expected to be published in 2021. The
subgroup will close following completion of these tasks.
The Severe Accidents (SA) TESG has completed a technical report on hydrogen management and then worked
on its closure report.
The Commissioning Activities (CA) TESG met twice in 2018 and in 2019 to share experiences on a variety ofcommissioning-related issues. The group is now focused on developing a document on methodology for postfuel load regulatory hold points definition. They intend to continue their activities as long as members continue
to show interest in exchanging information regarding commissioning-related issues.
In addition to this work, the EPRWG is also planning to develop a technical report on the application of the
break preclusion principle.

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5.2 AP1000 Working Group (AP1000WG)
The AP1000 DSWG includes the regulatory authorities of China (NNSA), India (AERB) and the United States(NRC). The United Kingdom regulatory authority (ONR) has ceased regulatory review activities for the AP1000
design in the United Kingdom following NuGen’s decision to pursue a different reactor design for the Moorside
project in Cumbria. In Canada, since CNSC completed a pre-licensing assessment of the AP1000 in June 2013 aspart of its Phase 2 evaluation, there has been no activity with Westinghouse Electric Company (Westinghouse)on further AP1000 review efforts. The Phase 2 vendor design review has been completed. In light of thesedevelopments, the regulatory authorities of the United Kingdom (ONR) and Canada (CNSC) remain in the
AP1000 Working Group as inactive members.
Between 2009 and 2021, the NRC, ONR, and NNSA finished their safety assessments for the AP1000 design,and drew the conclusion that the AP1000 design was acceptable according to the regulations of the UnitedStates, the United Kingdom, and China. These assessments were outside the terms of reference for MDEP, but
the outcomes facilitated the member regulators’ understanding and provided significant grounding for
AP1000WG discussion and co-operation.
In May 2019, the AP1000WG discussed the status of the AP1000 Digital I&C TESG and determined that thegroup, which had decided to meet as needed, had met once after making that decision and had no future work
planned. Based on the lack of plans for design-specific work, a lack of input from the AP1000WG members on
topics the TESG needed to address, and the existence of the active generic Digital I&C Working Group, thegroup decided to close the AP1000 TESG.
During the twentieth meeting in December 2019, the AP1000WG members decided that the group and its
supporting Commissioning TESG had no continuing work programme or the possibility, within the following two
years, of initiating a potential new work programme within the terms of reference of MDEP and thus there wasno justification for the AP1000WG or its TESG continuing to meet. Then the members determined to close theremaining TESG; requested the STC to endorse the conclusion that the AP1000WG should hold no further
meetings; and advised the STC to recommend to the Policy Group that the AP1000WG be closed, having
completed its tasks within the framework of MDEP.
Both the STC and PG accepted the recommendation with a direction that the group produce a closure reporthighlighting its successes and recommendations for any future work that lay outside the terms of referenceof MDEP.

Accomplishments and plan of work
Throughout the existence of the working group, members have exchanged information related to licensing,construction, commissioning, and initial operation issues in various countries. The documents have beenshared through the MDEP Library. Discussion topics have included in-containment condensate return, main
control room dose and habitability, reactor coolant pumps, squib valves and equipment qualification, hot andcold functional testing, hydrogen management, as well as discussions on lessons learnt from the Fukushima
Daiichi accident and the prevention and mitigation of severe accidents.
During this reporting period, the AP1000WG finalised a Technical Report on AP1000 Technical Exchanges
during the Design, Construction, and Commissioning of AP1000 Reactors (TR-AP1000WG-03) and it was approvedby the MDEP STC in November 2019. This report has been limited to the AP1000WG only based on a request bymembers. The AP1000WG published Common Understanding of the Hydrogen Control System for the AP1000
Design (TR-AP1000WG-04) in September 2020. It also published the Technical Reports: Lessons Learnt from
Implementation of the Common Position on FPOT for AP1000 (TR-AP1000WG-05) and Hot Functional and Startup
Testing Lessons Learnt (TR-AP1000WG-06) in May 2021.
For the closure activities, the working group determined the final approach for storage of the working groupmaterials that were to be saved. A closure report for the AP1000WG was finalised during its 21st meeting in June
2021. The AP1000WG was closed on 30 June 2021.

5.3 APR1400 Working Group (APR1400WG)
The APR1400 DSWG was established in August 2012 with four countries, though Finland later opted to leavefollowing the cancellation of the Olkiluto 4 project in 2015. The current participants are the regulatory authorities
of Korea, the United Arab Emirates, and the United States. The United Arab Emirates leads the working group.

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CURRENT ACTIVITIESThe first APR1400, Shin-Kori Unit 3 in Korea, has been in commercial operation since December 2016. ShinKori 4 was connected to the grid in April 2019 and it started its commercial operation in August 2019. The
operating licence for Shin-Hanul Unit 1 was granted in July 2021. Three additional units – Shin-Hanul 2 andShin-Kori 5&6 – remain under construction. The operating licence for Barakah Unit 1 in the United ArabEmirates was granted in February 2020 and its commercial operation commenced in April 2021. The operating
licence applications for Barakah Unit 2 and Barakah Units 3 and 4 were submitted in March 2015 and March
2017, respectively. At the time of writing this report, they were under review by the UAE Federal Authority for
Nuclear Regulation.
The application for the design certification for the APR1400 was submitted to the US NRC in December 2014
by KHNP and KEPCO and docketed in March 2015. The contents of the application included Design Control
Documents, Environmental Report, Technical Reports, Inspection, Tests, Analyses, and Acceptance Criteria(ITAAC) and Topical Reports. The Phase 1 safety evaluation was completed in February 2016 and the Phase 2
review was completed in May 2017. The NRC’s Advisory Committee on Reactor Safeguards completed its
review in July 2017. The Phases 4 and 5 reviews were completed in May 2018 and in July 2018, respectively.
After the final stage, Phase 6, US NRC issued the Standard Design Approval (SDA) for the APR1400 in September
2018 following a 42-month design certification review process. In May 2019, the US NRC published the APR1400
Design Certification rule for public comments and finally the certified APR1400 design became an effective
rule in Appendix F to 10 CFR Part 52 in September 2019.

Accomplishments and plan of work
Throughout 2019 and 2020, the nuclear regulatory agencies of Korea, the United Arab Emirates, and the UnitedStates continued to exchange information related to several significant APR1400 issues. The working group held
the 12th, 13th, and 14th MDEP APR1400WG meetings in April and October 2019 and September 2020, respectively,
including the Accident and Transient (A&T) TESG and the Severe Accident (SA) TESG meetings.
The United Arab Emirates took the lead on the Common Position on Irradiation Effect on the APR1400 Fuel
Bundle Spacer Grid Strength and initially distributed a draft version at the 12th meeting. Through the discussion
during the meeting and an additional comment period after the 12th meeting, the working group finally approved
the Common Position paper at the 13th meeting. Since then, the Common Position paper was submitted to the36th MDESP STC meeting in November 2019 and was approved as CP-APR1400-04. The STC Chair highlighted that
this Common Position has generic applications to other fuel designs to ensure minimum risk of spacer gridcrushing during seismic conditions and LOCA transients. The STC Chair suggested the Common Position beshared with the CNRA and the Committee on the Safety of Nuclear Installations (CSNI) under the Nuclear Energy
Agency (NEA).
The United Arab Emirates took the lead on the Technical Report on Hydrogen Recombiner Survey Resultsfor APR1400 design, and presented a draft version at the 12th meeting. Through the discussion during themeeting and an additional comment period after the 12th meeting, the working group approved this technicalreport at the 13th meeting. Afterwards, the technical report was submitted to the 36th MDESP STC meeting inNovember 2019 for approval. Since the MDEP STC recommended some additional points to improve the qualityof the technical report, the working group revised it and the STC approved it at the 39th STC meeting in June
2021.
Through the active discussion in the 7th SA TESG meeting, the APR1400WG decided to work on drafting atechnical report on the Comparison of the Regulatory Requirements for Probabilistic Risk Assessment (PRA).
The United Arab Emirates took the lead on this task and the APR1400WG discussed the specific details of thetechnical report at the 13th meeting. As a follow-up, the working group decided to finalise the technical reportat the 14th meeting and the STC approved it in June 2021.
Given the completion of the US NRC’s APR1400 Design Certificate Review and Rulemaking Process in
September 2019, the United States decided to reduce its participation in the activities of the APR1400WG.
Considering this situation, the working group had submitted a new configuration of the APR1400WG with two
active participating countries (Korea and the United Arab Emirates) and one non-active participating country(the United States). The Policy Group approved this new configuration at the 13th meeting in September 2019.
Since the Policy Group also decided not to extend the current MDEP mandate beyond 2022, the APR1400WG
decided to close its MDEP activities by the end of 2021, but Korea and the United Arab Emirates will continue
working on APR1400 Operating Experiences through bilateral co-operation. The APR1400WG is working tocomplete its planned activities by the end of 2021.

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5.4 VVER Working Group (VVERWG)
The VVER Working Group includes the regulatory authorities of China, Finland, Hungary, India, Russia andTürkiye. The working group members are reviewing plants at various stages of design and construction. In
Russia, the Leningrad-II Nuclear Power Plant Unit 1 is in operation; Unit 2 received an operational licence andminimum controlled power level at the end of August 2020 and entered commercial operation on 23 October
2020; while Units 3 and 4 have siting licences. The Novovoronezh-II Nuclear Power Plant Unit 1 is in operation;
Unit 2 began commercial operation at the end of October 2019. The Kursk-II Nuclear Power Plant Units 1 and 2
are under construction. The Smolensk-II Nuclear Power Plant siting licences have been issued for Units 1 and 2.
In Finland, one unit is under review for a construction licence at the Hanhikivi Nuclear Power Plant. At the
Kudankulam Nuclear Power Plant in India, two units are in operation, two units are under construction, and two
more have received siting licences. At Akkyuy in Türkiye, Units 1 and 2 are under construction, while Unit 3
received a construction licence and the licence application for Unit 4 is under review. In China, four VVER-1000
units are in operation at the Tianwan Nuclear Power Plant, two VVER-1200 units were granted construction
permission on 19 May 2021 and two more VVER-1200 units at the Xudapu Nuclear Power Plant have construction
licences in July 2021. The Hungarian regulator is currently reviewing the construction licence applications for
two VVER units at the Paks-II Nuclear Power Plant.

Accomplishments and plan of work
The VVERWG includes four technical expert subgroups that address specific technical issues: Severe Accidents(SA TESG), Fukushima accident Lessons Learnt (FUKU TESG), Reactor Pressure Vessel and Primary Circuit
Components (RPV&PC TESG) and Transients and Accidents (T&A TESG). The members meet regularly to
exchange information and experiences in their countries’ regulatory activities, approaches and legal
framework related to new designs.
In 2020-2021, the VVERWG published four Technical Reports and one Common Position after obtaining
approval from the STC:•

(TR-VVERWG-03) Technical Report on Regulatory Approaches related to Accidents and Transients
Analyses;•(TR-VVERWG-04) Technical Report on the Core Catcher;•(TR-VVERWG-05) Technical Report on Hydrogen Recombiners;•(CP-VVERWG-02) Common Position addressing Ex-Vessel Corium Stabilization in the Core Catcher.

The T&A TESG has identified topics for the further development of technical reports, such as environmental
qualification and uncertainty evaluation.
The SA TESG, after finalisation of two technical reports and the Common Position, started to develop atechnical report on long-term heat removal from the containment.
The Fukushima TESG resumed development of a draft Common Position addressing the Vienna Declaration
on Nuclear Safety since STUK and HAEA received the licensing documents.
The RPV&PC TESG finalised the Common Position on Reactor Pressure Vessel and Primary Components
Reliability for AES-2006 designs. It is currently developing a Technical Report on additional technical issues
related to reactor pressure vessel and primary components reliability for AES-2006 designs.
Furthermore, the VVERWG is drafting two Technical Reports on the similarities and differences between the
VVER-1000 and VVER-1200 designs, regulatory safety review approaches, and resulting evaluations. It will also
continue to document lessons learnt from design reviews and design issues faced during construction andcommissioning and early phases of operation.

5.5 HPR1000 Working Group (HPR1000WG)
The MDEP HPR1000 Working Group (HPR1000WG) was approved by the MDEP Policy Group in September 2017.
The group is focused on safety design reviews of the Hualong Nuclear Power Technology Co., Ltd. HPR1000
design. The HPR1000WG includes the regulatory authorities of Argentina (ARN), China (NNSA), South Africa(NNR), and the United Kingdom (ONR).

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CURRENT ACTIVITIESOn 30 January 2021, the first HPR1000, Fuqing Unit 5 in China, reached commercial operation. By June 2021,
construction work remains underway on 11 HPR1000 units at the Fangchenggang, Zhangzhou, Taipingling,
Sanao, Changjiang, and Fuqing sites in China. On 13 May 2021, the NNSA completed the site review for Lufeng
Units 5&6, which will build two more HPR1000 units in Guangdong, China.
In the United Kingdom, the Generic Design Assessment (GDA) of the UK HPR1000 officially commenced in
January 2017. Step 1 and Step 2 of the GDA were finished in November 2017 and November 2018, respectively.
In February 2020, the UK HPR1000 design passed Step 3 of the GDA, which continued the assessment work of
the previous step with increased emphasis on the arguments that underpin the safety and security claims.
The ONR is currently assessing the design for Step 4 of the GDA.
In Argentina, the government announced that the Secretary of Energy’s plans included a decision to build
an HPR1000. The ARN developed a Memorandum of Understanding (MOU) where a set of “high-level”
requirements complementing Argentina standards were defined as mandatory for the HPR1000 project. The
MOU was submitted to the licensee, Nucleoeléctrica Argentina S.A. (NA-SA).

Accomplishments and plan of work
During this reporting period, the HPR1000WG members continued to share information and experience on
regulatory issues and the status of HPR1000 projects in their respective countries. The working group
discussed the ONR Regulatory Observations (ROs) and the associated resolution plans as well as otherimportant technical matters identified in the GDA for the UK HPR1000. As China progressed in the construction
phase, the working group discussed the NNSA safety reviews on design changes and construction events ofthe HPR1000 units in China.
In September 2019, the members of the HPR1000 Working Group and its subgroups (Severe Accidents TESG
and Internal and External Hazards TESG) met to discuss the regulation process and regulatory activities andto work on developing the planned reports. The vendor representatives participated in several parts of themeeting to provide detailed presentations on the technical topics of interest for the members, and themembers also had opportunities to engage in direct dialogue with the vendor on critical technical issues. At
the end of the September 2019 meeting, group members toured the Fangchenggang plant under construction
and met with the licensee staff and site inspection staff. In addition to the September 2019 meeting, theHPR1000WG held two remote meetings due to the COVID-19 restrictions, and the Severe Accidents TESG (SATESG) and Internal and External Hazards TESG (Hazards TESG) also had meetings via videoconferencing.
To compare the main differences between the basic design options available for the HPR1000 design, theworking group decided to prepare a comparison table during the first meeting of the HPR1000WG. In August
2020, the Comparison Table of HPR1000 Design Characteristics, Version 1 was finalised. This table has been
limited to the HPR1000WG based on a request by members. It is a living document to which new design options
can be added in the future.
Between 2019 and 2020, the HPR1000 Working Group continued to develop a Common Position on
Fukushima lessons learnt based on the MDEP Common Position CP-STC-02, issued by the STC in September
2016. Member countries provided inputs to the paper to reflect their regulatory expectations regarding the
HPR1000 design and how the design could be enhanced to address Fukushima Daiichi issues. In November
2020, the working group finalised the Common Position (CP-HPR1000WG-01) Addressing Fukushima Daiichi
Nuclear Power Plant Accident-Related Issues, which was approved by the STC at the 38th STC meeting inJanuary 2021. This report identifies common preliminary approaches and regulatory expectations to address
potential safety improvements for HPR1000 plants, as related to lessons learnt from the Fukushima Daiichi
accident or Fukushima Daiichi-related issues. The report supplements CP-STC-02 and should be read in
conjunction with that document.
Early in the establishment of the HPR1000 SA TESG, the members agreed to produce a technical report tocompile the expectations of the regulators that are applied when assessing safety submissions and design
aspects associated with severe accidents. Therefore, the SA TESG collected information from all the member
countries regarding various aspects of the regulation, analysis, and management of severe accidents. In
December 2020, the SA TESG finalised a Technical Report on Regulatory Requirements and Practices for Severe
Accidents (TR-HPR1000WG-02) and provided it to the HPR1000WG. This report summarises the regulatory
requirements and expectations of the member regulators and highlights where consensus or differences exist.
Afterwards, the HPR1000WG reached a consensus on submitting this paper to the STC, which approved thetechnical report at the 38th STC meeting in January 2021.

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2019-2021 MDEP ANNUAL REPORTThe SA TESG also collected information from all the member countries regarding various aspects of the
HPR1000 Containment Combustible Gas Control System, and prepared a technical report based on the collected
information to identify common features of the HPR1000 design and develop a common understanding of theregulatory requirements of the member countries. In July 2020, the SA TESG finalised a Technical Report on
Hydrogen Control During Severe Accidents (TR-HPR1000WG-01) and it was finally approved by the STC at the37th STC meeting in September 2020.
The HPR1000 Hazards TESG has been developing a technical report on hazards to understand thesimilarities and differences in regulatory approaches to hazard assessment of the member countries, and thepotential implications of this on the design of the HPR1000. The Hazards TESG members are finalising thisreport. It will provide a high-level summary of each country’s regulator philosophy as well as a number of
pertinent hazards as examples of how the approaches are applied in practice.
In its latest programme plan, the HRR1000WG has established a number of objectives to be completed during
the 2021-2022 period. A new topic – high integrity components – has been added to the programme plan. The
working group will continue its efforts developing its next three Common Positions, on Sump Strainer
Performance, the Vienna Declaration on Nuclear Safety, and In-vessel Retention Strategy.

5.6 Vendor Inspection Co-operation Working Group (VICWG)
The goals of the VICWG are to:•Support MDEP Design-Specific Working Groups;•

Maximise the use of the results obtained from other regulators’ efforts in inspecting vendors;•

Understand the similarities and differences between MDEP national regulators’ quality assurance andquality management (QA/QM) requirements in order to improve regulators’ own requirements;•

Facilitate the adoption of good vendor oversight practices by national regulators;•

Harmonise the vendor inspection practices among MDEP regulators for inspections under the MDEP
protocol;•Continue joint and witnessed inspections and perform multinational inspections of vendors according
to the common QA/QM requirements;•

Focus vendor attention on areas of emerging risks;•

Focus licensee and vendor oversight on effective supply chain performance;•

Focus licensee and vendor attention on positive nuclear safety culture expected within the supply
chain;•

Continue to engage with the CNRA to consider how to maximise the use of information gathered
through VICWG activities;•

Consider the establishment of an NEA working group for vendor oversight, as part of the transfer of
ISWGs to NEA.

The working group enhances the understanding of each regulator’s inspection procedures and practices byco­ordinating witnessed and multinational inspections of quality assurance arrangements and safety related
components.
Witnessed inspections consist of one regulator performing an inspection of its criteria, observed byrepresentatives of other MDEP countries. The benefits to the observing countries include additional information
and added confidence in the inspection results.
Multinational inspections consist of one regulator conducting an inspection according to its own regulatory
framework with the active participation of one or more regulators. This allows the participating members to
use the results of the inspection that are applicable to their regulations. Multinational inspections are a tool
to gain vendor performance insights with minimal inspection resources from the participating regulators.
The working group maintains an annual list of planned inspections, providing the opportunity toco­operate and fully maximise the results from vendor inspection activity. The inspection results are sharedthrough the MDEP Library. The library includes not only the reports of witnessed and multinational

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CURRENT ACTIVITIES

inspections, but other inspection reports that may be of interest to the MDEP members. The VICWG routinely
engages with standard development organisations (SDOs) to exchange regulatory experience, encourageco­operation and influence the future activities of the SDOs. It continues to co-operate with important external
stakeholders such as the International Atomic Energy Agency (IAEA), CORDEL and the World Nuclear
Association (WNA) Supply Chain Taskforce. Furthermore, the VICWG engages with the CNRA Working Groupon Inspection Practices (WGIP) to provide opportunities to WGIP members to observe vendor inspections andto share VICWG Common Positions.

Accomplishments and plan of work
The VICWG continued to exchange experience on vendor inspection processes in order to understanddifferences in regulatory approaches and to identify trends and vulnerabilities in the international supply
chain encountered in vendor inspections. While inspection co-operation has been impacted by the COVID-19
pandemic, the working group has continued to engage and share information. A COVID-19 vendor inspection
impacts survey was produced and considered in a topic specific video conference held on 19 May 2020 tosupport the sharing of good practices and potential future activity. As national inspection programmes
adjusted with enhanced use of remote inspection, vendor inspection programme outcomes and the impacts
and lessons from the COVID-19 response were shared as part of country-specific updates in the VICWG
meetings.
During the reporting period, two witnessed inspections, one joint inspection, and two multinational
inspections were completed. Notably, the VICWG’s 3rd Multinational Vendor Inspection was conducted at a
Spanish manufacturer on 21-25 October 2019. Afterwards, the VICWG developed and finalised a Technical
Report on Assessment of Multinational Vendor Inspection of ENSA (Spain) (TR-VICWG-06). The 4th planned
multinational inspection of Framatome was initially postponed due to COVID-19 restrictions. However, theworking group trialled the delivery of a remote Multinational Vendor Inspection under the ASN’s leadership.
The multinational inspection was conducted in two stages, with the first completed on 3-6 May 2021 andexamining quality management arrangements. The second stage was completed on June 2021 and examined
special processes. This approach represents a further method for regulatory co-operation, and a learning
report will be produced.
The VICWG reviewed the outcomes of the 2018 CNRA/MDEP Nuclear Supply Chain Management Workshop
and published the proceedings from the joint workshop in November 2019. The proceedings served to informthe activities of the MDEP VICWG and provide the basis for the CNRA to decide on future activities or tasks. As
one of the priority activities from the workshop, the VICWG has continually focused on the establishment of astrong nuclear safety culture in the supply chain. It conducted a survey on safety culture and co-ordinated with
the CNRA Working Group on Safety Culture (WGSC) to ensure any work is complementary. In January 2021, the
VICWG published a Technical Report on Safety Culture in the Nuclear Supply Chain (TR-VICWG-07). This reportprovides a high-level summary of how each member country encourages or regulates safety culture in the
nuclear supply chain, based on the responses to the survey. Forward activities will continue to develop atechnical report of best practices for influencing safety culture in the nuclear supply chain.
The joint WGIP, WGHOF and VICWG COVID-19 Impacts on Inspection Practice Workshop was held virtuallyon 24 and 25 February 2021. The draft output from the joint workshop has been shared with the participants andwill be utilised to inform the CNRA WGIP 2022 workshop. All VICWG members will be invited to participate in
the 2022 workshop. In addition, the VICWG has been supporting the CNRA WGDIC in considering how existingvendor inspection processes could be applied to support Digital I&C Vendor Inspections. The VICWG also
supported the joint WGDIC and WGIP “Special International Nuclear Regulatory Inspection Workshop on Digital
Instrumentation & Control (DI&C)” held in Toronto, Canada, in June 2019. Moreover, the VICWG co-ordinatedwith WGRNR on a survey of oversight of suppliers at construction sites.
The VICWG continues to ensure that its programme documents and inspection protocols are effectively
maintained. In 2021, it published two updated Common Positions (CP-VICWG-02 and CP-VICWG-04) on
Witnessed, Joint, and Multinational Vendor Inspection Protocols, and on Mitigating the Risks of Counterfeit,
Fraudulent, and Suspect Items.

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2019-2021 MDEP ANNUAL REPORT

Next steps
The top 3 VICWG priorities for the next few years are:•Collaboration – Sharing of intelligence from vendor inspection programmes during biannual meetings,
enabling regulators to address areas of emerging risk, focusing on the risk of Counterfeit, Fraudulent
and Suspect Items (CFSIs) and the establishment of a strong nuclear safety culture in the supply chain.
Continued exchange of information and best practices on supply chain oversight among participating
regulators, focusing on suppliers that manufacture products for multiple counties.

•

Co-operation – Identify opportunities for witnessed, joint and multinational inspections, building on
the effective multinational inspections conducted to date.

•

Target areas of risk – Addressing the issues from the supply chain management workshop on aprioritised basis.

The VICWG programme plan has been updated to include the task sheets approved by the STC: (a) Supply chain
nuclear safety culture – potential collaboration with the CNRA WGSC; (b) Enhanced stakeholder engagement – toensure that the VICWG better leverages its regulatory influence to target areas of risk, i.e. licensees, regulators,
industry groups, standard development organisations, IAEA; (c) Commercial grade dedication and equipment
qualification – opportunity to influence IAEA publications in early stages of development. In addition, regulation of
emerging technologies (i.e. digitisation, modular constructions, and additive manufacturing/3D printing) as well as
supply chain oversight (i.e. supply chain mapping and interface management) will also be addressed by the working
group in future.
In 2020, the MDEP Policy Group decided to transfer the VICWG to the CNRA. To facilitate a smooth transition,
the VICWG has managed the transfer to maintain the existing core functionality while identifying opportunities totarget further risk reduction of supply chain management and vendor activity, reviewed the programme plan andgovernance given the potential increased membership and wider mandate, and learnt from the transfer of theother MDEP ISWGs including the on-boarding new members.
The VICWG activities will close under the current MDEP framework at the end of 2021. During 2022, the VICWG
will be working with the CNRA under the NEA auspices on the transition, with the official transition expected in
2023.

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INTERIM RESULTS

6. Interim results

MDEP is considered a long-term programme with interim results. Interim results are products that documentagreement by the MDEP members and are necessary steps in working towards increased co-operation andconvergence. The interim results for this reporting period include:•

The EPRWG published the Technical Reports: Hydrogen Management for EPR (TR-EPRWG-06), and EPR
Assessment of 2A Large Break Loss-of-Coolant Accident (2A-LOCA) Analysis (TR-EPRWG-07). It also
published updated Common Positions on the EPR Instrumentation and Controls Design (TR-EPRWG-01).

•

The AP1000WG published the Technical Reports: Hydrogen Control System for the AP1000 Design(TR-AP1000WG-04), Lessons Learnt from Implementation of the Common Position on FPOT for AP1000(TR-AP1000WG-05), and Hot Functional and Startup Testing Lessons Learnt (TR-AP1000WG-06). It also
finalised a Technical Report on AP1000 Technical Exchanges during the Design, Construction, andCommissioning of AP1000 Reactors (TR-AP1000WG-03), which is restricted to the AP1000WG based ona request by the members.

•

The APR1400WG published the Common Position (CP-APR1400WG-04) on Irradiation Effect on the
APR1400 Fuel Bundle Spacer Grid Strength. It published the Technical Reports: Hydrogen Recombiner
Survey Results for APR1400 design (TR-APR1400WG-04), and Comparison of the Regulatory
Requirements for Probabilistic Risk Assessment (PRA) (TR-APR1400WG-05).

•

The VVERWG published Technical Reports: regulatory approaches related to accident and transient
analyses (TR-VVERWG-03), and hydrogen recombiners (TR-VVERWG-05). It published a Technical Reporton the Core Catcher (TR-VVERWG-04) and a related Common Position (CP-VVERWG-02) addressing Exvessel Corium Stabilization in the Core Catcher. It also completed a draft Common Position on Reactor
Pressure Vessel and Primary Components Reliability for AES-2006 designs. The VVERWG continues todevelop two technical reports on similarities and differences among VVER designs, regulatory safety
review approaches and resulting evaluations.

•

The HPR1000WG published the Common Position (CP-HPR1000WG-01) Addressing Fukushima Daiichi
Nuclear Power Plant Accident-Related Issues. It also published the Technical Reports: Hydrogen
Control During Severe Accidents (TR-HPR1000WG-01), and Regulatory Requirements and Practices for
Severe Accidents (TR-HPR1000WG-02). The HPR1000WG is finalising a Technical Report on HPR1000
Hazards. It is also developing Common Positions on the Vienna Declaration on Nuclear Safety, Sump
Strainer Performance, and In-Vessel Retention Strategy.

•

The VICWG published a Technical Report on Safety Culture in the Nuclear Supply Chain (TR-VICWG-07).
It finalised the Technical Report on Assessment of Multinational Vendor Inspection of ENSA (Spain)(TR-VICWG-06), which is restricted to the VICWG based on a request by the members. The VICWG
updated two Common Positions (CP-VICWG-02 and CP-VICWG-04) on Witnessed, Joint and Multinational
Vendor Inspection Protocol; and Mitigating the Risks of Counterfeit, Fraudulent, and Suspect Items. The
VICWG conducted the 3rd and 4th Multinational Vendor Inspection in 2019 and 2021, respectively.

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NEXT STEPS – FUTURE OF THE PROGRAMME

7. Next steps – Future of the programme

MDEP was established in 2006 as a multinational initiative for a five-year period. It was extended for anotherfive-year period in 2012 by the Policy Group based on the value gained by the members. At its May 2014 meeting,the MDEP Policy Group requested a data collection be conducted among the members to prepare for a discussion
on MDEP’s mid- and long-term strategy. The questions focused on MDEP’s mission and expected deliverables,
the use of MDEP products, and the future of MDEP. The results of the data collection indicated that the members
continued to receive significant benefits from participation in MDEP and it should continue beyond 2017. The
members confirmed that the core activity should be the Design-Specific Working Groups and identified somerecommended improvements in the development of the programmes of work, defining the products andensuring knowledge transfer as reactors begin the operational phase. These findings were shared with the PolicyGroup at its June 2015 meeting. At this meeting, the Policy Group determined that MDEP should continue in its
current form for an additional five-year period after 2017 until the end of 2022. However, the Policy Groupstressed that going forward, MDEP should focus on design-specific activities. At its September 2019 meeting, thePolicy Group decided to sunset MDEP in its current form by 2022 as the EPRWG, AP1000WG, and APR1400WG
were expected to complete all activities specified in the programme plan by 2022. However, the Policy Groupaffirmed that for the MDEP designs that will remain active after 2022 (VVER and HPR1000), the work should
continue. At its October 2020 meeting, the Policy Group approved moving forward with plans to close the EPRWG,
AP1000WG, and APR1400WG by the end of 2021, and determined that a new MDEP governance structure shouldbe implemented in 2022. The STC is working with DSWGs on the scope of close-out activities, the required
knowledge management effort, and to determine the optimal timing to close their programme of work toproperly plan the closure reports and other activities required for an orderly shutdown.
The Policy Group also decided to transfer the VICWG to the CNRA. VICWG activities will close under the MDEP
framework at the end of 2021. During 2022, the VICWG will be working with the CNRA under the NEA auspiceson the process of transition, which is expected in 2023. The working groups on Digital Instrumentation andControl and Codes and Standards had both been transferred to the CNRA by 2019, since the STC and Policy Group
had approved the transfer of the generic activities to other organisations.
MDEP member countries have also stressed the need for, and benefits of, continuing co­operation among
members even after a specific design review has concluded. To that end, the STC has begun exploring different
options that can be utilised to transition existing co­operation within a DSWG outside of the MDEP, once theworking group has achieved its mandate under MDEP. It is working with the NEA to transfer the EPRWG
activities to the CNRA, as the EPRWG members have identified additional work related to operating reactorsthat is beyond the MDEP framework. The ABWR Working Group closed its activities under MDEP in May 2018,
and is now operating under the CNRA.
The regulatory authorities that are members of the VVER and HPR1000 Design-Specific Working Groups, as
existing members and considering their desire to continue the successful and mutually beneficial collaboration
under a new streamlined MDEP framework for international co-operation for new designs, agree that the
programme of work will be governed and implemented by a MDEP Management Board (MB) with the NEA serving
as the Technical Secretariat.
A special session of the MDEP Policy Group only for the members of the future framework, namely Argentina,
China, Finland, Hungary, Russia, South Arica, Türkiye, and the United Kingdom, was held in March 2021. The
general consensus from the special session was that: (a) a successful transition to the new MDEP framework
should be delivered first and then, at a later time, new member countries and new technologies can beconsidered; (b) harmonising regulatory practice should be a greater focus of working groups going forward;(c) work on cross-cutting issues could still be part of MDEP but awareness of co-operation with NEA working
groups on generic topics is necessary. The organisation of events and conversations with a broader group of
regulators is still of great interest for the members of the new MDEP framework.

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2019-2021 MDEP ANNUAL REPORTA transition team that consists of all member countries of the future framework was established toconsider the roles and responsibilities of the Policy Group and the STC, in order to help define the roles andresponsibilities of the new Management Board of the future framework. A Deputy STC Chair was selected tolead the MDEP transition to the future framework. Currently, the transition team is re-structuring the MDEP
terms of reference (ToR) with the aim of presenting the final proposal during the first meeting of theManagement Board. The transition team will also discuss the transition process and make preparations forthe first Management Board meeting, which will follow the last Policy Group meeting, by the end of 2021.

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LIST OF ABBREVIATIONS AND ACRONYMS

Appendix 1: List of abbreviations and acronyms

ABWRWG

Advanced Boiling Water Reactor Working GroupAERB

Atomic Energy Regulatory Board (India)

ASN

Autorité de sûreté nucléaire (Nuclear Safety Authority of France)

CNRA

Committee on Nuclear Regulatory Activities (NEA)

CNSC

Canadian Nuclear Safety Commission

CORDEL

Cooperation in Reactor Design Evaluation and Licensing

CP

Common Position

CSWG

Codes and Standards Working Group

DI&C

Digital instrumentation and control

DICWG

Digital Instrumentation and Controls Working Group

DSWG

Design-Specific Working GroupEDF

Electricité de France

EPRWG

EPR Working Group

FANR

Federal Authority for Nuclear Regulation (United Arab Emirates)

FOAK

First-of-a-kind

FPOTFirst plant only tests

GDA

Generic design assessment

HVAC

Heating, ventilation and air conditioning

HAEA

Hungarian Atomic Energy Authority

I&C

Instrumentation and controls

IAEA

International Atomic Energy Agency

ISWG

Issue-Specific Working Group

ITAAC

Inspection, Tests, Analyses, and Acceptance Criteria

KEPCO

Korea Electric Power Corporation

KHNP

Korea Hydro and Nuclear Power

LOCA

Loss-of-coolant accident

MDEP

Multinational Design Evaluation Programme

NDE

Non-destructive examination

NEA

Nuclear Energy Agency

NNSA

National Nuclear Safety Administration (China)

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NRA

Nuclear Regulation Authority (Japan)

NRC

Nuclear Regulatory Commission (United States)

NSSC

Nuclear Safety and Security Commission (Korea)

OECD

Organisation for Economic Co-operation and Development

ONR

Office for Nuclear Regulation (United Kingdom)

OOG

Owners and Operators GroupPC

Primary circuit components

PG

Policy Group

PRA

Probabilistic risk assessment

PSA

Probabilistic safety assessment

QA

Quality assurance

QM

Quality management

RO

Regulatory observation

RPV

Reactor pressure vessel

SDOStandard development organisation

SSMStrålsäkerhetsmyndigheten (Swedish Radiation Safety Authority)

STC

Steering Technical Committee

STUK

Säteilyturvakeskus (Radiation and Nuclear Safety Authority of Finland)

TAEK

Türkiye Atom Enerjisi Kurumu (Turkish Atomic Energy Authority)

TESG

Technical Experts Subgroup

TR

Technical Report

VICWG

Vendor Inspection Co-operation Working GroupVVER

Water-water energetic reactor

VVERWG

VVER Working Group

WGDIC

Working Group on Digital Instrumentation and Controls (NEA/CNRA)WGHOFWorking Group on Human and Organisational Factors (NEA)

WGIP

Working Group on Inspection Practices (NEA/CNRA)WGRNRWorking Group on the Regulation of New Reactors (NEA/CNRA)WGSC

Working Group on Safety Culture (NEA/CNRA)WNAWorld Nuclear Association

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REVISED OR NEW DOCUMENTS AND PUBLICATIONSAppendix 2: Revised or new documents and publications

Working group programme plans: www.oecd-nea.org/mdep/
CP-EPRWG-01 Common Positions on the EPR Instrumentation and Controls Design, May 2020.
TR-EPRWG-06 Technical Report on Hydrogen Management for EPR, May 2020, https://oecdnea.org/mdep/documents/EPRWG06_TechnicalReport_Hydrogen_Management.pdf.
TR-EPRWG-07 Technical Report on EPR Assessment of 2A Large Break Loss of Coolant Accident (2ALOCA) Analysis, May 2020, https://oecd-nea.org/mdep/documents/EPRWG07_TechnicalReport_
2A%20LOCA_public.pdf.
TR-AP1000WG-03 Technical Report on AP1000 Technical Exchanges during the Design, Construction,
and Commissioning of AP1000 Reactors, November 2019.
TR-AP1000WG-04 Common Understanding of the Hydrogen Control System for the AP1000 Design,
September 2020, https://oecd-nea.org/mdep/documents/Technical_Report_AP1000_Hydrogen_
Control_System_Approved_Sept2020_FINAL.pdf.
TR-AP1000WG-05 Technical Report on Lessons Learnt from Implementation of the Common Position
on FPOT for AP1000, May 2021, https://oecd-nea.org/mdep/documents/AP1000_TR_LessonsLearnt_
ImplementationCP_FPOT_FINAL.pdf.
TR-AP1000WG-06 Technical Report on Hot Functional and Startup Testing Lessons Learnt, May 2021,
https://oecd-nea.org/mdep/documents/AP1000_TR_hotfunctionaltesting_startuplessonslearnt_FINAL.pdf.
CP-APR1400-04 Common Position on Irradiation Effect on the APR1400 Fuel Bundle Spacer Grid
Strength, October 2019, https://oecd-nea.org/mdep/common-positions/cp_apr1400wg_01_fuel%20
seismic.pdf.
TR-APR1400WG-04 Technical Report on Hydrogen Re-combiner Survey Results for APR1400WG design,
March 2021, https://oecd-nea.org/mdep/documents/TR-APR1400WG-04_hydrogenrecombiner_
surveyreport_FINAL.pdf.
TR-APR1400WG-05 Technical Report on Regulatory Requirements for Probabilistic Risk Assessment(PRA) APR1400 nuclear power plants, April 2021.
CP-VVERWG-02 Common Position Addressing Ex-Vessel Corium Stabilisation in Core Catcher, June
2021, https://oecd-nea.org/mdep/documents/CP-VVERWG-02_CoriumStabilization_CoreCatcher_FINAL.pdf.
CP-VVERWG-03 Common Position on Reactor Pressure Vessel and Primary Components Reliability for
AES-2006 Designs, 2021.
TR-VVERWG-03 Regulatory Approaches Related to Accidents and Transients Analyses, March 2019,https://oecd-nea.org/mdep/documents/VVERWG_TR_%20Accident_Transients_0_7_STC%20comm_
FINAL.pdf.
TR-VVERWG-04 Technical Report on Core Catcher, June 2021, https://oecd-nea.org/mdep/documents/
tr-vverwg-04_CoreCatcher_Final.pdf
TR-VVERWG-05 Technical Report on Hydrogen Recombiners, June 2021, https://oecd-nea.org/mdep/
documents/TR-VVERWG-05_HydrogenRecombiners_FINAL.pdf.
CP-HPR1000WG-01 Common Position Addressing Fukushima Daiichi Nuclear Power Plant AccidentRelated Issues, November 2020, https://oecd-nea.org/mdep/documents/CP-HPR1000WG-01_CP_
AddressingFukushimaDaiichiNPPAccident-RelatedIssues.pdf.

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TR-HPR1000WG-01 Hydrogen Control During Severe Accidents, September 2020, https://oecd-nea.org/
mdep/documents/TR-HPR1000WG-01%20Hydrogen%20Control%20During%20Severe%20
Accidents_clean%20copy_FINAL.pdf.
TR-HPR1000WG-02 Technical Report on Regulatory Requirements and Practices for Severe Accidents,
December 2020, https://oecd-nea.org/mdep/documents/TR-HPR1000WG-02_TR_RegulatoryRequirements_Practices_Severe%20Accidents.pdf.
CP-VICWG-02 Common Position on Witnessed, Joint and Multinational Vendor Inspection Protocol,
November 2020, www.oecd-nea.org/mdep/common-positions/cp-vicwg-02.pdf.
CP-VICWG-04 Common Position on Mitigating the Risks of Counterfeit, Fraudulent, and Suspect Items,
June 2021, https://oecd-nea.org/mdep/documents/VICWG_CFSI_CommonPositions09Jun2021_
approved_FINAL.pdf.
TR-VICWG-06 Technical Report on Assessment of Multinational Vendor Inspection of ENSA (Spain),
September 2020.
TR-VICWG-07 Technical Report on Safety Culture in the Nuclear Supply Chain, January 2021,
https://oecd-nea.org/mdep/documents/TR-VICWG-07_TR_SafetyCulture_NuclearSupplyChain
Final_Rev29Jan2021_FINAL.pdf.
NEA/CNRA/R(2019)3 Proceedings of the 2018 Committee on Nuclear Regulatory Activities/MDEPWorkshop on Nuclear Supply Chain Management, November 2019, www.oecd-nea.org/nsd/docs/
2019/cnra-r2019-3.pdf.

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MULTINATIONAL DESIGN EVALUATION PROGRAMMEThe Multinational Design Evaluation Programme (MDEP) was established in 2006 to develop innovative
approaches to leverage the resources and knowledge of the national regulatory authorities that are currently
or will be tasked with the review of new nuclear power reactor designs. MDEP members are the regulatory
authorities of Argentina, Canada, China, Finland, France, Hungary, India, Japan, Korea, Russia, South Africa,
Sweden, Türkiye, the United Arab Emirates, the United Kingdom and the United States. The Nuclear Energy
Agency serves as Technical Secretariat for MDEP. The International Atomic Energy Agency also takes part in
the work of MDEP.

NUCLEAR ENERGY AGENCYThe OECD Nuclear Energy Agency (NEA) was established on 1 February 1958. Current NEA membershipconsists of 34 countries: Argentina, Australia, Austria, Belgium, Bulgaria, Canada, the Czech Republic,
Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Japan, Luxembourg, Mexico, theNetherlands, Norway, Poland, Portugal, Korea, Romania, Russia (suspended), the Slovak Republic, Slovenia,
Spain, Sweden, Switzerland, Türkiye, the United Kingdom and the United States. The European Commission
and the International Atomic Energy Agency also take part in the work of the Agency.
The mission of the NEA is:–

to assist its member countries in maintaining and further developing, through international
co-operation, the scientific, technological and legal bases required for a safe, environmentally soundand economical use of nuclear energy for peaceful purposes;–

to provide authoritative assessments and to forge common understandings on key issues as input togovernment decisions on nuclear energy policy and to broader OECD analyses in areas such as energy
and the sustainable development of low-carbon economies.

Specific areas of competence of the NEA include the safety and regulation of nuclear activities, radioactive
waste management and decommissioning, radiological protection, nuclear science, economic and technicalanalyses of the nuclear fuel cycle, nuclear law and liability, and public information. The NEA Data Bank
provides nuclear data and computer program services for participating countries.

Cover page photo credits: Unit 3 and 4 of the Tianwan Nuclear Power Plant (Li Mengrui).

www.oecd-nea.org/mdep

Printed by the OECD Nuclear Energy Agency for the Multinational Design Evaluation Programme