MATERIALS QUALIFICATION design rules and codes, fuel performance codes As said, GenIV system prototypes and demonstrators, certainly in their first phase, will necessarily be constructed using structural and fuel materials that are already largely available today, on which some return of experience exists from previously operated reactors. However, innovative nuclear design such as for the ESNII systems can rely on very limited return-of experience, depending on the system.25 Thus the materials selected need to be qualified for the conditions expected in the prototypes and demonstrators, including off-normal conditions that may be faced during accidents and to which they need to be proven to resist for sufficient time: high temperature, high irradiation levels, and compatibility with coolants, for instance between HLM and structural components.26 In turn, the actual operating conditions of prototypes and demonstrators will be influenced and determined by the properties of these materials, after applying suitable safety margins, to avoid their degradation beyond acceptable limits. Off-normal conditions are especially important in the nuclear field in the aftermath of the Fukushima accident, as a consequence of which stricter safety requirements are imposed and more effort is needed to demonstrate structural integrity in accident scenarios. Accident scenarios translate into load excursion with high temperatures and load rates. The temperature range for mechanical properties assessment needs therefore to be extended and strain rate properties in the relevant range are necessary. If such data do not exist, then specific research programmes are needed. In this context materials qualification means generation and maintenance of evidence to ensure that material or equipment will operate on demand, under specified service conditions, meeting system performance requirements.27 Materials qualification is the pre-requisite for the establishment of robust design rules for structural components and fuel performance codes and is therefore defined as pre-normative research, where pre- normative refers to research aimed at establishing standards or common procedures to ensure that materials and components in nuclear reactors are designed and operated in accordance with the best available engineering practices and the current scientific knowledge. Materials qualification requires dedicated experiments both out of pile and in pile,28 to collect comprehensive and reliable data of the material prope...
MATERIALS QUALIFICATION. Materials qualification is the process used by Recovery Engineering, Inc. to assure that a given supplier's material or process will conform to requirements in a given application. The process consists of these steps: * Review and approval of all new engineering drawings by Purchasing and Design Engineering. Input from suppliers may also be requested during this stage of drawing review. * Inspection of all prototype and sample parts by Quality Control Department. * Reliability testing by Engineering Department.
