Optimisation of New Build Spent Fuel Management and DisposalPeter Haslam

Public Policy AdvisorNuclear Industry Association

25 January 2011

Structure of Presentation

• Overview of Government Spent Fuel Management “base case”

• Outline of work carried out with NDA to identify opportunities and feasibility of optimising the “base case”

• Initial results of preliminary scoping studies with NDA

• 60 years operation would generate a total of approximately 3,400 assemblies per EPR, including time for planned outages

• Each Spent Fuel Assembly contains approximately 530kg Uranium

• A Single EPR will produce approximately 1800tHM over 60 years of operation

Spent Fuel Generation

RWMD assumptions related to New Build Spent Fuel Inventory

•RWMD will publish a Disposal System Safety Case. This will provide safety arguments supported by illustrative disposal concepts for three geological environments.

•The DSSC considers the MRWS Baseline Inventory and an upper inventory scenario which includes wastes and SF arising from a new nuclear build power programme

•The upper inventory scenario assumes construction of four AP1000 and four UK EPR corresponding to a generating capacity of 10 GW(e) which leads to an inventory of 13,000tHM of spent fuel (assumed 60 year operating lives)

•The illustrative disposal concepts assume use of high integrity disposal canisters (each holding four SFA)

•The DSSC recognises that the disposal concepts will not be chosen until future stages

The Spent Fuel Management Case Base

• Cooling in reactor fuel pool 2-10 yrs• Transfer to on-site Spent Fuel Interim Storage Facility• Store for around 100 years post discharge from reactor for temperatures

to fall to meet GDF temperature constraints of bentonite buffer material• Transfer to an encapsulation facility • Encapsulation of long-stored fuel in KBS3 copper containers (maximum 4

fuel assemblies)• Transfer to GDF for disposal (new-build emplacement after c.2130)

Spent Fuel removed from

reactor

Assemblies transferred to reactor fuel

pool

Underwater storage of spent

fuel in reactor fuel pool for initial

cooling

On-site Spent Fuel Interim Storage Facility

Off-Site Geological

Disposal Facility

Spent Fuel Spent Fuel Interim StorageSpent Fuel Transfer

Spent Fuel Encapsulation Final Disposal

Reactor fuel pool

Transfer of spent fuel to Interim

Storage Facility

Spent fuel encapsulation facility

Encapsulation of spent fuel for

disposal

Initial Spent Fuel Cooling

SFA loaded into transport flasks for

transfer to encapsulation plant.

Spent Fuel stored for period of up to

100 yearsTransport to GDF

Optimisation of Base Case

• Current strategy safe, practical and deliverable

• Opportunities to optimise certain aspects– Storage periods– Storage Arrangements– Encapsulation facility/facilities– Optimisation of current reference disposal conceptual

design– Consideration of other disposal concepts– ILW Management – Scheduling

• NDA RWMD was contracted by NIA to identify issues and options that could result in opportunities for optimisation

Working with NDA-RWMD

• RWMD has undertaken work commissioned and fully funded by the Nuclear Industry Association

• Scope:– Investigate the feasibility of and issues associated with

storage and encapsulation plants for spent fuel– Investigate issues with alternative transport and disposal

package types– Identify issues and options that could result in the

optimisation of the GDF concept to meet the characteristics of both legacy and new build waste

– Investigate the potential benefits of alternative disposal concepts

RWMD Report

• Published November 2010

• NDA website• http://www.nda.gov.u

k/documents/upload/Geological-Disposal-Feasibility-studies-exploring-options-for-spent-fuel-from-new-nuclear-power-stations-November-2010.pdf

Spent Fuel Interim Storage period• RWMD initial disposability assessment

indicated cooling period of the order of 100 years required before disposal

• Based on temperature constraint on bentonite backfill

• New work indicates above ground storage period could be reduced to around 50 years by judicious mixing of long cooled and short cooled fuel

• Other feasible options which also permit earlier emplacement include:– Smaller diameter canisters with

reduced heat load, or– Undertake research on the

temperature limit in the bentonite buffer

Fuel Handling and Centralised Storage (1)

• Base case assumes one store per site and on-site storage post decommissioning until GDF is available and fuel is sufficiently cooled

• Advantages that each site manages its own waste

• Disadvantage in duplication of facilities each of which will require safety and security infrastructure

• Centralised storage could reduce overall costs and allow complete early clearance of multiple sites

Fuel Handling and Centralised Storage (2)

Encapsulation• Encapsulation of spent fuel into form suitable for

final disposal

• Base case assumes:– Use of copper canister concept– Packaging at reactor site with transport to

GDF

• Encapsulation plant is complex and expensive facility

• Swedish concept assumes single encapsulation plant and centralised storage

• UK legacy fuel also requires encapsulation

• Opportunities to share facility between legacy and new build or between new build operators

Alternative Disposal Pakages• Use of alternative containers in reference concept

GDF• Larger casks with more SFA = higher thermal

loading• Considers viability of a single Multi-Purpose

Container (MPC) for storage – transport – disposal • Could remove need for repackaging and additional

handling of fuel• Existing designs of MPC would require significant

up rating and redesign of GDF infrastructure and handling systems

• Conceptually a smaller MPC could be designed for increased compatibility with geological disposal and UK transport infrastructure

• Further work needed to justify early sealing of SF in the container and ability to make future transport and disposal safety cases

Alternative Disposal Concepts

• Consideration of alternative disposal concepts

• In-tunnel Axial Concept – more suitable for larger containers as no rotation of container

• RWMD has identified practical options for emplacement of MPC type containers (e.g. NUMO (Japan) cavern system)– Suited to MPC package– Potential for earlier

emplacement due to delayed buffer backfill

Next Steps

• NIA working group to consider scope of further research

• Engagement with Government where implications for Managing Radioactive Waste Safely process

• Operators to engage with local communities on site specific waste proposals for new nuclear power stations

www.niauk.org