The purpose of this report is to present the most promising ATF concepts currently under development at various fuel vendors, research institutions and nuclear laboratories around the world and to provide the reader an independent assessment of the state of the art and potential for development and implementation related with each type of the ATF.
This Special Topic Report addresses the degradation mechanisms that could potentially affect the performance of spent fuel stored in a dry, inert environment for periods up to ~100 years. The focus of the review is on the spent nuclear fuel rods, and not on the storage system components such as the casks or the canisters and their internal hardware elements.
The overall objective of this Special Topic Report (STR) is to provide the knowledge of how the reactor environment (fast neutron flux, temperature, water chemistry, etc.) and the Zr-alloy microstructure, which is a function of material chemistry and manufacturing process, impacts fuel performance during normal operations, transients, design basis accidents and interim dry storage.
This report is intended to provide basic understanding on the mechanical properties of zirconium alloys, stainless and ferritic steels and nickel alloys. The information can then be used by customers to evaluate their components.
(LCC15)
This report describes the historical development of the water chemistry in primary side of the PWR and VVER plants since 1950s up to present. Starting with the first research PWR plants in USA without applying any water chemistry addition of neither alkaline reagent nor hydrogen, lot of fuel performance degradations were experienced in 1950s and 1960s, such as heavy fuel deposits, flow restrictions across the core, reactivity losses and high radiation fields. Even the first AOA indications were experienced in a PWR with low core duty operating without applying water chemistry treatment.
(LCC15)
This report describes and explains the past and present issues related to secondary system chemistry and materials behaviour.
It starts with the relation between design and material evolution influence on chemistry selection, as well as guidelines for the secondary system. It also explains the behaviour of added reagents and of impurities in the secondary system. The integrity and long-term behaviour of the plant is largely considered.
(ZIRAT24/IZNA19 STR)
The overall objective of this Special Topic Report (STR) is to provide the knowledge of how the reactor environment (fast neutron flux, temperature, water chemistry, etc.) and the Zr-alloy microstructure, which is a function of material chemistry and manufacturing process, impacts fuel performance during normal operations, transients, design basis accidents and interim dry storage.
(ZIRAT23/IZNA18 AR)
The overall objective of the ZIRAT Programme is to enable the nuclear utilities and laboratories to:
The objective is met through review and evaluation of the most recent data on zirconium alloys, identification of the most important new information, and discussion of its significance in relation to fuel performance now and in the future. Included in the review are topics on materials research and development, fabrication, component design and in-reactor performance.
(ZIRAT23/IZNA18)
In materials test reactors (MTRs), materials are subject to intense neutron irradiation to study the induced changes. As MTRs are able to reproduce material degradation undergone by materials in power reactors, they provide essential support to the study of ageing of materials in power reactors. MTRs are also being used to irradiate new cladding materials and fuels that are being developed as Accident Tolerant Fuel (ATF) systems.
(LCC14)
This first report on PWRs, VVERs, CANDUs and PHWRs summarises and analyses the results to assess in which specific situation the results are applicable and gives the point of view of A.N.T. International expert. Instead of giving a short summary of each paper presented at the conference, the report covers the key facts, either new or of significant interest for LCC customers.
This is of particular interest to discuss how to consider different presentations that may sometimes give contradictory or conflicting results.
The main examples concern zinc addition into the primary coolant, potential replacement of LiOH by KOH in PWRs as used in VVERS, Film Forming Amines, dispersant addition, hydrazine alternates. The advantages, disadvantages, questions or limitations of new solutions are explained.
