The Report on Control Assembly Technology which constitutes Volume III of the series of Fuel Material Technology Reports (FMTRs) will be available during the Spring of 2014. It describes the designs, manufacturing, performance and issues related to BWR/PWR/VVER/CANDU Control Assemblies with Ag-In-Cd (AIC), B4C, Hf absorber materials and stainless steel structural materials.
This handbook contain a technical assessment of the expected performance of spent nuclear fuel (SNF) during extended dry-storage time periods and the condition of such fuel at the end of dry storage.
The principal focus of the reviews is on SNF and the effects of dry storage rather than on dry-storage containers and the related storage facilities. The objective is to provide background information on the likely behavior of materials comprising water reactor fuel assemblies and on the performance of integral assemblies under conditions typical of dry storage for extended intervals of time.
In brief, the technical assessment supports a conclusion that, although technical issues have been postulated with regard to long-term storage, there are no high-risk concerns with the extension of dry storage to long times; with proper planning and implementation.
This Fuel Design Review Handbook intends to provide a guide to the items that have the greatest influence on fuel performance and prioritize the audits that are recommended. A review of all aspects of the fuel design is not feasible or necessary within the time constraints of the utility and the vendor. The objective is to do the most effective audit in the shortest time period. The Handbook provides the “what, why and how” for the audits by describing the design criteria, their influence on performance and the approach to reviewing the associated design features for the three distinct technical areas of nuclear, thermalhydraulic, and mechanical/materials design, each written by experts in their field. A guide for design tool verification is included as well as a guide to auditing the vendor design QA system.
The objective of the Fuel Fabrication Process Handbook is to provide guidance for a cost effective audit which uses audit time on areas which are most likely to affect the performance of the PWR/VVER and BWR fuel. The FFPH focuses on a “Process Audit” procedure, the audit of the fabrication process parameters for making high quality fuel. The FFPH provides the “what, why and how” to look at in an audit by:
- Listing the generic fabrication process steps for all components and their assembly (what to look for).
- Identifying important audit points and the attendant potential effect of deviations on performance (why to look).
- Assess the fabrication and QC process control at critical points (how to look).
This Handbook is an updated and expanded version of the previous FFPH Handbook published in 2005. More than 35 organisations worldwide bought this Handbook. The expansion constitutes two sections on Statistical Quality Control and Software Quality Assurance. Statistical QC is a vital part of process control, the establishment of sampling plans and the qualification of inspection methods. The QA of software is important for auditing the software for the expanding automation of fabrication methods.
This first volume of the Fuel Material Technology Report covers short general outlines of the designs of PWR, BWR, CANDU, VVER and RBMK reactors but with focus on the corresponding fuel assembly and supporting structure designs together with the rational for the selection of the materials used in the different applications. This volume also gives an overview of the in-reactor fuel performance, of fuel performance codes and the manufacturing process of the fuel assembly.
In this second volume of the Fuel Material Technology Report, the following topics for different water cooled type reactors are covered:
- Effect of radiation on the various fuel assembly materials as well as the interaction between materials and cooling water chemistry in this radioactive environment.
- Water chemistries in different reactor types
- Fuel design criteria and operating limits
- Fuel performance during Loss Of Coolant Accidents and Reactivity Initiated Accidents
- Fuel performance during intermediate storage
- Trends and potential burnup limitations
The primary objective of this volume of the Fuel Material Technology Report, FMTR Vol. IV, is to provide guidance in improving fuel reliability. To reach this objective, various Poolside and Hot Cell Examinations techniques may be used. A good knowledge of the pros- and cons- of the different techniques can guide the utility or fuel vendor to select the most cost efficient techniques for their specific goals. A second objective of this Report is to document this knowledge in a form which can be updated as new information, and methods become available.
One of the major present challenges to nuclear energy lies in its commercial competitiveness. To stay competitive, the industry needs to maximize the availability and capacity factors of nuclear power plants while reducing maintenance and fuel cycle costs and enhancing safety. Extended burnup is one of the methods applied to meet these objectives. There are a number of issues related to normal operation, anticipated operation occurrences, design basis accidents and dry storage that need resolution to be able to successfully implement extended burnup. This special topic reviews the potential consequences of increased burnup on fuel. Recommendations are also given on how to remedy the high burnup issues.
With increased burnup, processes going on inside a nonfailed fuel rod decrease pellet density, lower the fuel melting temperature and thermal conductivity, increase the fission gas release. Also, a high burnup structure is formed at pellet average burnups in excess of about 50 MWd/kgU This volume I of the report describes the processes going on inside a nonfailed fuel rod during normal operation. The associated volume II of the report describes the corresponding information during accident conditions (RIA and LOCA).
This Report is a comprehensive review and evaluation of the high strength nickel alloys (625, 718, X-750 and A286) used for PWR/VVER and BWR fuel assembly components. These alloys have been used for spacer grids, bolts and springs since the start of the LWR industry. The report concentrates on the good performance record as well as a description of the reported failures, their causes and remedies. The relationship of various heat treatments to the microstructures and their corrosion resistance are discussed.