IAEAInternational Atomic Energy Agency

TM-45455

Technical Meeting on

Spent Fuel Storage Options

Yumiko Kumano

Radioactive Waste and Spent Fuel Management Unit

Division of Radiation, Transport and Waste Safety - NSRW

IAEA Safety Standards and Activities on Safety of

the Long-Term Storage of Spent Nuclear Fuel

IAEA 2

Overview

�SSG-15

� IAEA Nuclear Safety Action Plan

- International Expert Meeting

- Revision of SSG-15

�Joint WG on Guidance for an Integrated Transport

and Storage Safety Case for Dual Purpose Casks

2

IAEA 3

SSG-15:

Storage of Spent Nuclear Fuel

3

IAEA 4

Configuration of IAEA Safety Standards

GSR Part 5

GSR Part 4

GS-R-3

�GSR Part 2

NS-R-3

�SSR-4

IAEA 5

SSG-15: Storage of Spent Nuclear Fuel(1)

2009

2012

OBJECTIVES

• To provide up-to-date guidance and recommendations on the design, safe operation and assessment of safety for the different types of spent nuclear fuel storage facility (wet and dry)

• Considering different types of spent nuclear fuel from NPPs

• Include storage beyond the original design lifetime of the storage facility

SCOPE

• Spent nuclear fuel storage facilities that may be either collocated with other nuclear facilities or located on their own sites.

• NOT specifically intended to cover the facility if it is a part of the operational NPP or reprocessing facility

• NOT provide comprehensive / detailed recommendations on physical protection.

IAEA 6

SSG-15: Storage of Spent Nuclear Fuel(2)

2009

2012

1. INTRODUCTION

2. PROTECTION OF HUMAN HEALTH AND ENVIRONMENT

3. ROLES AND RESPONSIBILITIES

RESPONSIBILITIES OF THE GOVERNMENT / REGULATORY BODY / OPERATING ORGANIZATION / SF OWNER

SAFEGUARDS & PHYSICAL PROTECTION SYSTEMS

4. MANAGEMENT SYSTEM

SF MANAGEMENT / RESOURCE MANAGEMENT

PROCESS IMPLEMENTATION

5. SAFETY CASE AND SAFETY ASSESSMENT

DOCUMENTATION OF THE SAFETY CASE

6. GENERAL SAFETY CONSIDERATIONS FOR STORAGE OF SF

DESIGN OF SF STORAGE FACILITIES

COMMISSIONING OF SF STORAGE FACILITIES

OPERATION OF SF STORAGE FACILITIES

DECOMMISSIONING OF SF STORAGE FACILITIES

IAEA 7

SSG-15: Storage of Spent Nuclear Fuel(3)

2009

2012

APPENDIX I

SPECIFIC SAFETY CONSIDERATIONS FOR

WET OR DRY STORAGE OF SPENT NUCLEAR FUEL

APPENDIX II

CONDITIONS FOR SPECIFIC TYPES OF

FUEL AND ADDITIONAL CONSIDERATIONS

ANNEX I

SHORT TERM AND LONG TERM STORAGE

ANNEX II

OPERATIONAL AND SAFETY CONSIDERATIONS

FOR WET AND DRY SPENT FUEL STORAGE FACILITIES

ANNEX III – VII

EXAMPLE OF THE SECTIONS IN OPERATING PROCEDURES/ SITE CONDITIONS, PROCESSES AND EVENTS FOR CONSIDERATION / POSTULATED INITIATING EVENTS

IAEA 8

IAEA Nuclear Safety Action Plan

- International Expert Meeting

- Revision of SSG-15

8

IAEA

Safety Vulnerabilities

Peer Reviews

Emergency Preparedness and Response

Regulatory Bodies

Operating Organisations

IAEA Safety Standards

Communication

Protection of People + Environment

Research + Development

Legal Framework

Embarking Countries

Capacity Building

Actions on IAEA Secretariat

Member States

Other Relevant Stakeholders

IAEA ACTION PLAN ON NUCLEAR SAFETY

12 Point Plan

Adopted by Board of Governors

Endorsed by All Member States

- 12 Actions

- 39 Sub actions

- 170 Activities

- 650 Tasks

IAEA

Action Plan• Strengthen the emergency

notification system

• Enhance the transparency and

effectiveness of communication

among operators, regulators and

various international organizations

• Review application of INES scale as a

communication tool

• Organize international experts

meetings IEMs

AchievementsInternational Experts’ Meetings (IEMs)

• Reactor and Spent Fuel Safety

• Communication Effectiveness

• Seismic and Tsunami Hazards

• Decommissioning + Remediation

• Human and Organizational

Factors

And more…•Radiological Assessments

iiii ii

“BAt this (Fukushima Ministerial) Conference,

we will present a report outlining the

conclusions of the international expert

meetings held so farB”

Action Plan 11.

COMMUNICATION AND DISSEMINATION OF INFORMATION

IAEA

INTERNATIONAL EXPERTS’ MEETING

REACTOR AND SPENT FUEL SAFETY 1

• MEETING

• 230 experts - 44 Member States 4 international

organizations

• Objectives

• Analyse relevant technical aspects

• Understand more fully its root causes

• Share lessons learned

• OVERVIEW

• More attention on Mitigation

• Severe accident management

• Combination of hazards and multiple-units

• Key systems for safe state

IAEA

INTERNATIONAL EXPERTS’ MEETING

REACTOR AND SPENT FUEL SAFETY 2

• Reactor Session

• Reinforcement of Defence in Depth

• Availability of reliable I&C capability

• Containment venting + filtering, hydrogen mitigation, fire

safety

• Data for analysis, severe accident modelling codes

improvements, and specialized operator training

possibilities

• Important for successful accident management

• Spent Fuel Safety Session

• Structural integrity of spent fuel storage

• Improve cooling arrangements: redundancy, diversity

• Hardened instrumentation for SFP

• Research : metal-water reaction; hydrogen generation;

release of radioactive products and transport/dispersion

• Management of damaged spent fuel and corium

IAEA

Action Plan 6.

REVIEW AND STRENGTHEN IAEA SAFETY STANDARDS

Action Plan•IAEA to review, and revise as

necessary

•Member States to utilize as broadly

and effectively as possible the IAEA

Safety Standards

WES-related Activities (WASSC)• Review of whole Requirements

����No major gaps, no need for amendment

• identified a series of issues; some for WASSC

and others being common with RASSC

and/or NUSSC.

NUSSC/WASSC related issues:

NWSI - 1) Interim storage of spent fuel (SF)

The safety of SF should be ensured at all times:

�Strategies for SF management should be re-examined

�This examination should be done with respect to the various

options available

�The SGs should be reviewed/revised after the re-

examination exercise is concluded.

IAEA

Action Plan 6.

REVIEW AND STRENGTHEN IAEA SAFETY STANDARDS

Review of SSG-15 (Storage of Spent Nuclear Fuel)Consultancy (Sept. 2012):

to review SSG-15 and provide experts’ opinion on the necessity of

the revision in light of lessons learned from Fukushima

�Conclusions from the consultancy

• SSG-15 is in a very good shape for its intended purpose.

• Recommend addendum to some paragraphs in order to better

capture extreme situations such as multiple initiating events

occurring simultaneously.

� 6.61(instrumentation and control)

� 6.98 (operational aspects: combinations of initiating events)

• Better to be made in the Safety Guide level

Way Forward:

�Start preparation to initiate revision process (addendum to SSG-15)

following up activities on the revision process of other relevant SRs.

IAEA

Outcome of the Consultancy - Discussions

� Main lessons coming from the Fukushima Daiichi

NPP accident:

• if a severe event or a combination of events occurred at a

site, all the facilities at that site are likely to be impacted,

• facility operating organization and crisis management

organization should be capable to deal with severe

accident situations, and

• vital functions, necessary to limit the consequence of

severe situations, should be maintained.

The defense in depth should be strengthened and mainly

the last levels: control of severe plant conditions and

mitigation of radiological consequences.

IAEA

Outcome of the Consultancy – Recommendations(1)

Recommendations

1. The operator should ensure that monitoring equipment for

key safety functions is available and operating after BDBA.

� Addendum to that effect should be made at para. 6.61.

Para 6.61 (Instrumentation and control)

When practicable, control and protection functions should be designed to be

mutually independent. If this is not feasible, detailed justification should be

provided for the use of shared and interrelated systems. Account should be

taken of ergonomic factors in the design of alarms and indications to the

operating personnel. Control and monitoring equipment should be calibrated

for its intended use.

IAEA

Outcome of the Consultancy – Recommendations(2)

2. Para 6.98 should be amplified to the extent that

combinations of initiating events are considered.

Para 6.98 (Operational aspects)

There are other safety considerations that should be taken into account in

the development of operating procedures and contingency and emergency

arrangements. It should be noted that many events would be addressed

either as anticipated operational occurrences or as design basis accidents.

However, some of these events could also lead to severe accidents, which

are beyond the design basis. Whilst the probability of such beyond design

basis accidents occurring is extremely low, in the preparation of operating

procedures and contingency plans the operating organization should

consider events such as the following:

(a) Crane failure with a water filled and loaded cask, suspended outside the pool;

(b) Loss of safety related facility process systems such as supplies of electricity, process

water, compressed air and ventilation;

(c) Explosions due to the buildup of radiolytic gases; *..

IAEA 18

Joint WG on Guidance for an

Integrated Transport and

Storage Safety Case for Dual

Purpose Casks (2011-2013)

18

IAEA 19

Joint WG on Guidance for an Integrated Transport

and Storage Safety Case for Dual Purpose Casks

19

Background� Growing number of SNFs caused by delays in decision on SF disposition

�Necessity of additional storage capacity

1. Wet storage

2. Dry storage

H Use of the DPCs designed for both transport / storage

� Intention to provide guidance to MSs for integrating safety cases for

storage and transport in a holistic manner

�Establishment of a joint international working group

Objective1. To provide an IAEA document containing recommendations and

guidance for the structure and contents of an Integrated Safety Case for

a dual purpose storage and transport cask.

2. Recommendation for changes to be made to existing IAEA documents

IAEA

Working Group

20

Scope of the document

� Dual Purpose Casks – Transport / Storage

- Guideline for establishing integrated safety cases in consideration of

the interface issues between storage and transport casks.

� Storage period – 50 years (short term) / 100 years (long term)

- Specific description with examples for explaining the application of

the methodology, including aging assessments

� Mainly for metallic casks, consideration for canisters being added later

Working Group

Chair: B. Droste (BAM, Germany)

SWG leads: M. Hirose (NFT, Japan)

J. Harvey (NDA, UK)

I. Reiche (BfS, Germany)

D. Wolff (BAM, Germany)

Secretary: P. McConnell (SNL, USA)

IAEA: Y. Kumano, K. Varley

IAEA

Activities

21

April 2012: 2nd Plenary meeting� Review / Comment / Revise the first draft

� Major issues

� Definition of Safety Case for DPCs?

� How to address Acceptance Criteria?

� How to discuss aging issues?

April 2011: 1st Plenary meeting � Adoption of the Terms of Reference

� Drafting outline and contents

Base document: Technical Guide – Package Design Safety Reports for the

Transport of Radioactive Material (PDSAR)

by European Association of Competent Authorities

April 2013: 3nd Plenary meeting� Mostly finalized document

� Recommendations to WASSC / TRANSSC

� Future activities

IAEA

Dual Purpose Cask

22

DPC transport package� Designed for off-site transport

before / after storage

� Compliance with international /

national regulations for transport

� With impact limiters

DPC storage package� Designed for storage of spent fuel

� Compliance with international

standards / national regulations for

storage (+ on-site transport)

� Often has a closure system with

additional lids, with lid interspace

pressure monitoring

IAEA

Safety Case for DPCs

23

Main features to be considered� How to define acceptance criteria

� Ageing consideration for long-term

storage and transport after storage

� Design / Fabrication

� Operation

� Retrievability

� Ageing management programme

� Licensing consideration

� Licensing for both storage /

transport

� Licensing renewal (esp. for

transport

� Change of transport regulations

/ new technology development

� And*

� Inspections before

transport

� Records during fabrication/

operation

IAEA

Proposed Structure of a DPC safety case

24

Part 1

Contents List

Dual Purpose Cask Safety Case

Part 2

Structural Analysis

Subdocument

(if necessary)

Subdocument

(if necessary)

Thermal Analysis

Activity Release Analysis

External Dose Rates Analysis

Criticality Safety Analysis

Administrative Information

Specification of Contents

Specification of Dual

Purpose CaskStorage and Transport

ConditionsGeneral Design Considerations

and Acceptance Criteria

Compliance with Regulatory

Requirements

Operation

Emergency Plan

Ageing Considerations

Decommissioning

Maintenance Plan

Management Systems

IAEA

Summary of Recommendations to TRANSSC/ WASSC

25

Recommendations to TRANSSC

� Introducing a definition of DPC packages

� Considerations on ageing of packages

� Considerations of DPC packages to “Transitional

Arrangements”

� Develop a section on compensating arrangements and gap

analysis methods in guidance-level document

Recommendations to WASSC

� Detailed description on “ageing management program” in

SSG-15

� Support developing generic test conditions for storage and on-

site transport

IAEA

BThank you for your attention