Committee on the Safety of Nuclear Installations (CSNI)

International Workshop on Safety of Long Term Interim Storage Facilities

Munich, Germany, 21-23 May 2013

Hosted by Gesellschaft für Anlagen und Reaktorsicherheit (GRS) mbH

GENERAL INFORMATION

The OECD Nuclear Energy Agency (NEA) Committee on the Safety of Nuclear Installations (CSNI) Working Group on Fuel Cycle Safety (WGFCS) will hold an International Workshop on Safety of Long Term Interim Storage Facilities, hosted by the Gesellschaft für Anlagen und Reaktorsicherheit (GRS) mbH between 21 and 23 May 2013 in Munich, Germany. These pages include information on the event and a call for papers to be submitted for presentation at the workshop.

Working under the mandate of the CSNI, the objective of the WGFCS is to advance the understanding for regulators, technical support organizations (TSO) and operators of relevant aspects of nuclear fuel cycle safety in NEA member countries.

Many radioactive materials within the nuclear fuel cycle present a significant hazard for 50 years or more. Such materials include spent nuclear fuel, high-level waste, legacy waste and other nuclear materials that have no current outlet than storage. These materials are often held in long-term storage as an interim stage within their lifecycle. Lifecycles can include reuse or disposal. Hazards require effective safety to maintain the risk of realising those hazards to as low a level as reasonably possible. Hazards that extend beyond the life of a facility in which they are generated require careful management and understanding of their safety.

Thus, the WGFCS aims within this workshop to advance the understanding within NEA member countries of safety of long term interim storage across the whole of the nuclear fuel cycle by bringing together and discussing the strategies and practices of storing High Level Waste and Spent Nuclear Fuels.

Using the vehicle of NEA to draw together, via discussion, the knowledge gained from work being delivered on a national level by regulators and operators within member states, the IAEA’s “Coordinated Research Project on Demonstration of Spent Fuel Performance during Very Long term Storage” and EPRI’s Extended Storage Collaboration Program.

Such discussions will help to deliver a coherent view of good practice sustainable storage of radioactive materials within a regulated framework that will be used as guidance for operators and regulators within all phases of the nuclear fuel cycle.

OBJECTIVES OF THE WORKSHOP

The Workshop over the three days will examine how members are addressing the challenge of Sustainable Safety for Spent Fuels, Wastes and other radioactive materials managed in a similar way, from a regulatory and industry viewpoint and aims to share the international current status in this area and improve/develop links that will aid in delivering solutions to the challenges.

The objective of this workshop is to discuss and review current national activities, plans and regulatory approaches for the safety of long term interim storage facilities dedicated to spent nuclear fuel (SF), high level waste (HLW) and other radioactive materials with prolonged storage regimes. Safety authorities and their TSO, Fuel Cycle Facilities (FCF) operating organisations and international organisations are invited to share information on their approaches, practices and current developments.

The initial product will be the workshop proceedings. However, it is anticipated that the workshop output will form the platform from which the WGFCS will develop a more in depth document, for instance a State-of-the-art Report.

BACKGROUND OF THE WORKSHOP

Nuclear Fuel Cycles always have a period of storage of radioactive materials built within them. These storage periods extend from the management of fuel manufacture materials (mainly uranium and plutonium) to the cooling and management of spent nuclear fuel until its next stage of treatment (post processing, reprocessing, disposal or other) to the storage of high-level waste from decommissioning or legacy operations.

Disposal is the choice as a final destination for the spent nuclear fuel for many NEA member countries. Others are awaiting the development of operations and facilities that will effectively close their fuel cycles. In both cases there is need for a disposal facility, or repository,  for spent fuel or high level waste or other radioactive materials generated within the nuclear fuel cycle that have long term hazards from which the public require protection.

To date no final repository for HLW or SF from commercial reactors is in operation and many NEA member countries have expressed their intention to plan for long term interim storage. Time periods for storage up to 300 years are being discussed.

There are several different approaches for interim storage of HLW and SF currently used of which the main storage concepts are:

• Dry storage in vault, casks and containers.
• Wet storage, in silos, pools, outside reactor operating areas.

These approaches were chosen based on limited storage periods of 40-60 years. The new, much longer, interim storage periods currently being discussed will bring additional regulatory and operational aspects into focus. Such aspects include:

• Ageing management;
• Periodic safety reviews, knowledge management;
• Long term behaviour not only of the used fuel and radioactive materials but also of the systems structures and components needed for storage;
• Surveillance and possible replacement of storage facilities with the need to transfer the contents
• Impact of the increased importance of extreme natural events following Fukushima

The licensing and related regulatory framework will have to consider these new prolonged inter-generational timescales and ensure that safety will be demonstrated until the material is received at the repository or other future management route. Such demonstrations will include appropriate surveillance and methods for feeding back the collected operational experience into the storage regime.

Last reviewed: 11 April 2013