Structural Materials for Liquid Metal Cooled Fast Reactor Fuel Assemblies. Operational Behaviour

One of the IAEA's statutory objectives is to 'seek to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world'. One way this objective is achieved is through the publication of a range of technical series. Two of these are the IAEA Nuclear Energy Series and the IAEA Safety Standards Series. According to Article III.A.6 of the IAEA Statute, the safety standards establish 'standards of safety for protection of health and minimization of danger to life and property.' The safety standards include the Safety Fundamentals, Safety Requirements and Safety Guides. These standards are written primarily in a regulatory style, and are binding on the IAEA for its own programmes. The principal users are the regulatory bodies in Member States and other national authorities. The IAEA Nuclear Energy Series comprises reports designed to encourage and assist R and D on, and application of, nuclear energy for peaceful uses. This includes practical examples to be used by owners and operators of utilities in Member States, implementing organizations, academia, and government officials, among others. This information is presented in guides, reports on technology status and advances, and best practices for peaceful uses of nuclear energy based on inputs from international experts. The IAEA Nuclear Energy Series complements the IAEA Safety Standards Series. This report summarizes the results of two IAEA sponsored technical meetings, conducted in 2008 and 2011, and associated consultancies directed toward a common set of goals. These technical meetings and their venues were as follows: - IAEA Technical Meeting on Status and Trends of Stainless Steel Cladding and Fuel Assembly Materials and Components for LMR, held in Hyderabad, India, 2-4 July 2008; - IAEA Technical Meeting on Design, Manufacturing and Irradiation Behaviour of Fast Reactor Fuels, held in Obninsk, Russian Federation, 30 May-3 June 2011. One of the main objectives of these meetings was to 'share and exchange information on stainless steel structural materials for liquid metal cooled fast reactor fuel assemblies', producing a final report that would: - Identify the different varieties of austenitic, nickel based, ferritic-martensitic (FM) and oxide dispersion strengthened (ODS) steels having demonstrated success or potential improved performance as structural components of fast reactor fuel assemblies, with particular emphasis on fuel cladding; - Summarize the manufacturing processes of liquid metal fast reactor (LMFR) fuel cladding tubes, rods for end plugs, sheets, wrappers, wires, etc., starting from ingot preparation; - Summarize the irradiation behaviour of these steels in fast reactor service; - Focus in particular on the ODS variants of ferritic and FM steels as the path forward to achieving higher burnup of fuel in fast reactors. One major conclusion from this activity is that there is a need to develop a strong international capability to explore the radiation resistance, especially to void swelling, of ODS variants of ferritic and FM alloys using ion simulation techniques as surrogates for currently unavailable high flux fast reactors.