The role of technological innovation for dry storage of used nuclear fuel

1. The role of technological innovation for dry storage of used nuclear fuel H.Issard – June 2010

2. Summary • The innovation mandate • Mission & Objectives • Key performances • Innovation areas • Innovation process • Main steps of the Process • Methods & tools for innovation • Examples of Innovations • Conclusion International conference on management of spent fuel from nuclear power reactors– June 2010

3. innovation mandate • Mission and objective • Innovation is a keystone for the strategy of the back end, • Need to integrate evolutions and New technologies • Nuclear utilities needs evolve • Additional payload, acceptance of higher discharge burnups and easier licensing process • Key performances • Storage capacity and economical performance • Safety and ease of licensing • Ease of operation and reduction of doses of operators • Impact of selected technology on sustainable development • Impact of selected technology on proliferation issues International conference on management of spent fuel from nuclear power reactors– June 2010

4. innovation areas • Storage equipment design • Cost, capacity, flexibility of the storage system • Interfaces for handling, loading and transfer • Tie down designs • Quick evacuation procedure • Justification methodology • Modelisation • Knowledge of safety margins • Material behaviour for longer periods • Damaged fuels International conference on management of spent fuel from nuclear power reactors– June 2010

5. innovation process • Innovation process • Perform regular interviews with customers and utilities • Access, capture and reuse of experience feedback and knowledge • Creativity and idea generation • Screen ideas for added value • Selection of ideas and R&D plan • Factors of success • Participatory innovation : creation, collaboration, communication • Involvement of everyone, including top management • incentives International conference on management of spent fuel from nuclear power reactors– June 2010

6. Innovation process , methods • AREVA logistics open space of innovation : ID school • Initiatives : creativity groups • Express ideas through drawings, models • Creative ambiance, develop participatory innovation International conference on management of spent fuel from nuclear power reactors– June 2010

7. E EXPLORE(Exploration, Impregnation): Identify all the aspects of the problem without paying too much attention to the aspect which brought the problem to light; look at it from all angles without any prejudices or preconceived ideas, become immersed in it and take it on board Every step is the result of a divergent and a convergent phase F I FORMALIZE(Expression, Analysis, Formulation, Incubation): Analyze and structure in detail the formulation of the problem and all its components and break it down into targeted areas of research; specify objectives, requirements and selection criteria C A IDEAS (Creation, Ideas, Enrichment, Inspiration) : Put together and produce for each area of research a large number of solutions and original ideas; deepen and enrich ideas CONSTRUCTION (Prioritization, Choice, Valorisation): : Range, prioritize, select ideas following the previously defined selection criteria; combine and enrich ideas (cross-fertilization) ACTION(Application, Organisation, Action Plan) : For any solution, build an action plan, i.e. a program with detailed facts and figures for implementation Innovation process, methods • Methods to galvanize innovation • Brainstorming, Triz, etc • Creativity method developed by AREVA : method EFICA ® International conference on management of spent fuel from nuclear power reactors– June 2010

8. Tools for innovation • Tools for management of ideas • Ideas are welcome • Idea management data bank (example ID HALL) • Regularly, a committee evaluates each new idea: • Apply • Stand by • Rejected International conference on management of spent fuel from nuclear power reactors– June 2010

9. Examples of Innovations • Baskets : High performance design solutions for sub-criticality • Trend towards high burn-ups for LWR fuels ( 60 000 MWd/tHM for the EPR) higher fissile contents = higher U-235 enrichments (5%) or higher plutonium contents for MOX. Sub-criticality is guaranteed by the basket geometry and the material. real challenge to design high capacity baskets. Use of a family of borated alloys : Borated stainless steel plates or Metal matrix composites, formed by casting, powder metal processes. • All characteristics (composition, mechanical) have been studied, including the homogeneity of Boron content and the resistance to corrosion in borated water; they are satisfactory. Boralyn™ with 15% B4C is an example of high performance materials for sub-criticality: it can be used for the structural resistance of the baskets. There is also the new Boron Metal Matrix Composite (MMC) material with an aluminium matrix and up to 25% B4C. International conference on management of spent fuel from nuclear power reactors– June 2010

10. Examples of Innovations • Innovation in containment • A new type of fluorocarbon O-ring gaskets has been developed and qualified to keep the guaranteed leak rate for a large range of temperatures -40°C to 200°C. • The long term behaviour at high temperature of EPDM O-ring gaskets has been studied with innovative methodology , to establish time-limit versus temperature for EPDM O-rings. International conference on management of spent fuel from nuclear power reactors– June 2010

11. Examples of Innovations • Mitigation of hydrogen risk • For the mitigation of hydrogen risk in the cavity of casks, several catalytic recombiners have been developed and qualified, with a sufficient capacity to stabilise the hydrogen concentration bellow the flammability limit. In cooperation with French research institute IRCELYON. • Recombiner (dry conditions) Recombiner dry /wet Box for recombiners International conference on management of spent fuel from nuclear power reactors– June 2010

12. Examples of Innovations • Complete range of high performance neutron shielding materials • TN has developed high performance neutron shielding materials resisting to fire tests (self extinguishing) : TN® VYAL B, TN® HYPOP and TN® BORA for sub-criticality. These materials are adapted to different thermal environments and can be selected depending the temperature of use. • Solutions for thermal and structural management • For a given metallic containment vessel containing a given number of used fuels, the necessary thickness of neutron shielding material increases when Burnup of fuel increases. Innovation : a better heat evacuation system to compensate the negative effect of thermal insulation of neutron shielding material (polymers are generally low heat-conductive materials) : thermal conductors, fins, special surface treatments, and minimizing gap between cask inner wall/basket . International conference on management of spent fuel from nuclear power reactors– June 2010

13. Examples of Innovations • Spent fuel dry storage systems • TN®DUO • Storage Transport International conference on management of spent fuel from nuclear power reactors– June 2010

14. Examples of Innovations • Spent fuel dry storage systems • TN®NOVA • Cannister Overpack transport cask International conference on management of spent fuel from nuclear power reactors– June 2010

15. Conclusion • The role of innovation for the management of used fuel is to bring important benefits in term of performance, safety and public acceptance. • With innovation, the nuclear industry, and especially the back end is looking towards the long term and engaged in preparing a future with less CO2 emissions. International conference on management of spent fuel from nuclear power reactors– June 2010