Nuclear Fuel Cycle and Materials
Management of Spent Fuel from Power Reactors
DEMO - Coordinated Research Project (CRP) on Demonstrating Performance of Spent Fuel and Related Storage System Components during Very Long Term Storage (CRP-T13014)
Dry storage facilities have already required license extensions and more extensions are anticipated. It is therefore important to confirm the continued performance of spent fuel and related important storage system components, potentially through very long term storage periods e.g. exceeding 100 years.
To support such assessments, examinations of spent fuel performance have been and will be performed. Considering that a full range of spent fuel types and conditions are deployed around the world, DEMO will focus on existing systems (in lieu of new designs) and specifically light water reactor fuel in dry storage. In many cases, lessons learned may be applicable to other conditions including new designs.
While involving a number of countries, DEMO will coordinate with other relevant on-going efforts in Member States, including the Extended Storage Collaboration Program (ESCP) initiated by the US. Through improved coordination Member States can yield increased joint benefits for all participants. The aim is to generate results in a form that are useful to countries considering or starting nuclear power programmes as well as to countries with established nuclear power programmes (and existing accumulations of spent fuel).
The overall results should be a widely shared improvement in the nuclear power community’s ability to support the extension of licenses for spent fuel storage. CRP results are also expected to facilitate subsequent transport and disposal.
DEMO is scheduled to last until 2016.
Specific Research Tasks and Details
The DEMO CRP will coordinate appropriately with the broader scope of the SPAR-III CRP, but focuses more specifically on light water reactor spent fuel in very long term dry storage. The specific research objectives were developed in consultation with experts familiar with on-going gap analyses (gap between anticipated technical needs and existing technical data):
- Evaluate mechanisms for stress corrosion cracking (SCC) as a way of breaching spent fuel canisters in a marine environment.
- Evaluate monitoring for stress corrosion cracking (SCC) as a mechanism for breaching spent fuel canisters in a marine environment (in order to evaluate the confinement capability of welded stainless steel canisters and to protect the integrity of the contents).
- Evaluate degradation of the spent fuel and the confinement capability of the spent fuel canister or container (avoiding penetrations that could compromise integrity).
- Determine the effect of drying and storage on spent fuel cladding behaviour during subsequent normal transport (particularly effects that might impact the ability to handle fuel after that transport).
- Determine whether predictive models based on laboratory experiments adequately predict behaviour of full assemblies, including the interaction of the rods with assembly hardware under prototypic storage conditions (given that full assemblies have a range of characteristics relevant to storage and transport).
- Evaluate the confinement capability of concrete cask systems, including enabling examination of existing actual casks.
- Evaluate long-term confinement in spent fuel casks, focusing on the bolted lid for normal and accident conditions during storage and transport.
- Evaluate long-term confinement in spent fuel casks, focusing on metal gaskets for normal and accident conditions during storage and transport.
- Evaluate long-term neutron shielding capability.
- Evaluate system effects analytically by integrating important components of spent fuel storage demonstration in a "prototypic" manner.