Introduction of topics to be addressed and ideas for ... · Introduction of topics to be addressed...

International Atomic Energy Agency

Introduction of topics to be addressed

and ideas for future work

Stephen Whittingham

Head of Transport Safety Unit

International workshop on the development and application of a safety case for dual purpose casks for

spent nuclear fuel

IAEA International Workshop DPC May 2014 1


Dual Purpose Casks in context - experience

• Spent fuel has been routinely transported over the past

50 years

• Cask designs have developed over that time to

accommodate the developing reactor power

programmes and associated reactor fuel designs,

resulting in increased fuel burn-ups and enrichments

and different fuel pin designs/configurations

• The cask design justifications by designers and the

assessment by Regulatory Bodies have extended in

scope and complexity over that time

IAEA International Workshop DPC

May 2014 2


Dual Purpose Casks in context - experience

• Transport is a continuous cycle operation involving

• Cask loading, transport and cask unloading, or,

• Cask loading, transport and cask storage

• Cask designs have benefited from operational experience

• All aspects of transport such as design, manufacturing,

testing, operations, maintenance, repairs and record

keeping have benefited from quality control oversight and

inspections from the evolvement of quality assurance and

quality management systems


May 2014 3


Dual Purpose Casks in context – the future

• The concept of programming work several decades in

the future is not new, example decommissioning

programmes

• What is new for Dual Purpose Casks is that the industry

will purposely package spent fuel in a transport cask with

the intention of storing it for decades before transporting

the cask again in the public domain

• It is therefore important to remember that Dual Purpose

Casks is an INTERIM SOLUTION

• Perhaps as a reminder of this Dual Purpose Casks

(DPC) should be renamed Interim Storage and Transport

(IST) Casks


May 2014 4


Dual Purpose Cask

Safety Case

Storage Facility

Safety Case Interface

Issues

Interface between Transport Cask and Storage

Facility Safety Cases


May 2014 5


• In Europe a European Directive 2011/70/EURATOM

came into force in 2013 requiring EU Member States to

notify the Commission, by August 2015, of their national

programme for spent fuel and a waste management

system.

• Interim storage is one component of an overall waste

management plan

• The Dual Purpose Cask is not a solution in itself

Spent Fuel Management System – Dual Purpose

Casks


May 2014 6


• This workshop considers the development and

application of a safety case for Dual Purpose Casks

• The storage environment and the effects of storage

residence time will be determined by the ability to

demonstrate in the cask safety case the impact of these

two aspects upon the demonstrable compliance of the

cask with transport safety regulatory requirements at the

time of transport


Casks


May 2014 7


Wider issues

Dual Purpose

Cask Safety

Case

Storage Facility

Safety Case

Interface

Issues


Casks

Transport to interim

storage

Transport to recycle

or disposal of SF


May 2014 8


Adoption of Dual Purpose Cask in Spent Fuel

Management Strategies – wider issues

If the adoption of the interim storage strategy becomes the

norm, then in some countries with spent fuel stored in

casks for several decades after the shutdown of a reactor

• In time there will be a generation which has never

witnessed the transport of spent fuel in the public domain

in living memory

• Not only having no experience of transporting spent fuel,

the public will be asked to accept a transport cask that

was manufactured and loaded several decades ago

• The model of public acceptance of risk several decades

in the future may be a prohibitive factor in the context of

DPC timeframes


May 2014 9



Management Strategy – wider issues

• The fuel arising from a lifetime of a reactor could be of

the order of 4400 fuel assemblies, with the following

approximations for PWR reactors

• 190 fuel assemblies in core

• Up to 60 years reactor operation

• 15 – 18 months reload cycles

• 25 - 30% reload factor

• 5 - 6 cycle fuel

• 55 – 75 GWs/Te HM

• This is equivalent to 200 – 300 Dual Purpose Casks for

a reactor lifetime fuel loading


May 2014 10




• A large amount of work has been invested in developing

standards and guidance relating to waste management

• Understandably the approach focuses on waste

(characterisation, conditioning and ageing effects) and

storage facilities (safety case approach)

• All of this work is in the context of a controlled, and

licensed, nuclear facility environment

• The DPC approach now introduces the concept of

transporting the part of a ‘storage facility’ that contains

spent nuclear fuel in the public domain; potentially

many decades after it was constructed


May 2014 11




Timing and number of transports is a consideration

• The schedule to transport from the storage facility to

elsewhere will depend upon the capacity of the

receiving facility to handle the casks

• The transport programme may take several years to

complete

• The casks may need to be transported earlier than

planned so decay storage could be problematic

• The casks will be transported when the public has

received no direct benefit (power generation could have

ended decades earlier)


May 2014 12


Transport safety

• The transport regulations will require that a Dual Purpose

Cask design for spent fuel will meet the transport

regulations existing at the time of transport

• The developed safety case for a Dual Purpose Cask and

the regulatory regime to manage competent authority

approval of the designs will mitigate the risk of storing

casks that cannot demonstrably meet the transport

regulatory requirements

DPC in the context of a waste management strategy

• DPC documentation should make reference to its role in the

strategic waste management context

Summary


May 2014 13


The adoption of the DPC concept will include transport

specific issues including:

• Stakeholder engagement, relating to transporting casks

manufactured and loaded several decades earlier

• The time needed to transport DPCs from their storage

facility (perhaps a factor that will influence their capacity)

• The risk model perceived by a society several decades in

the future (and how this can be judged over time)

• Recognition of the transport related issues of a DPC

beyond the safety of the package design during transport-

storage-transport

• Contingency planning to provide effective response to

periodic reviews and inspection and surveillance regimes

when necessary

Summary


May 2014 14


Theme 1

• Cask design and operation requirements

• Periodic safety review of casks

• License renewal process

• Management system issues

Topics to be addressed in this workshop


May 2014 15


Theme 2

• Definition of design specification

• Maintenance and repair of casks

• Inspection and surveillance regimes

• Preservation of records and knowledge management



May 2014 16


Theme 3

• Current knowledge basis for long term storage

• Periodic safety review of casks

• Implementing outputs from periodic design reviews

• Is there conflict between transport and storage acceptance

criteria



May 2014 17


Panel session

• TECDOC – how can it be used in design

• Scope of TECDOC – what is not included

• How could the TECDOC be put in wider waste management

context

Future activities

• Should other package contents be addressed

• Would additional international cooperation benefit:

• the study of ageing management

• the development or implementation of the safety case concept



May 2014 18


Stephen Whittingham Head of Transport Safety Unit Division of Radiation, Transport & Waste Safety Department of Nuclear Safety and Security email: [email protected]


May 2014 19

Introduction of topics to be addressed and ideas for ... · Introduction of topics to be addressed...

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