The Working Group on Fuel Safety has been set up by the Committee on the Safety of Nuclear Installations (CSNI) and it has been working in accordance with the CSNI Strategic Plan to address cross-cutting issues related to fuel behaviour in accident conditions, including work on associated aspects of thermal-hydraulics, oxidation, chemistry, mechanical behaviour and reactor physics. This group was originally the Special Expert Group on Fuel Safety management (SEGFSM), later evolving into the Working Group on Fuel Safety Margins (WGFSM) before becoming the WGFS.
The main mission of the Working Group on Fuel Safety (WGFS) is to advance the current understanding and address safety issues related to fuel safety.
The specific mandate is as follows:
The group will aim to facilitate international convergence on fuel safety issues, including experimental approaches, interpretation and use of the experimental data or of other relevant information.
The group will perform its activities mainly through organising topical meetings on specific subjects or through small task forces dedicated to covering specific programme items.
Leaking fuel impacts and practices
Objectives of the task are:
The task started with a questionnaire where about 50 questions were answered in 23 sets from 14 countries. A report has been drafted and has been reviewed in the working group.
RIA fuel rod codes benchmark
The scope of activity was to organize a benchmark of RIA fuel rod codes based on a set of consistent, recent experiments performed in the NSRR and CABRI test reactors. In order to maximize the benefits from this exercise, a consistent set of 4 experiments on very similar highly irradiated fuel rods tested under different experimental conditions were used:
The participation into the benchmark took 17 organizations representing 14 countries, which provided solutions for some or all the cases that were defined. In terms of computer codes used, the spectrum was also large as solutions were provided with FALCON, FEMAXI coupled to TRACE, FRAPTRAN, RANNS, RAPTA, SCANAIR, TESPAROD and TRANSURANUS.
The final report has been prepared to be published.
Mechanical testing of fuel cladding for RIA applications
The task reviewed the test methodologies in use in NEA member countries for characterising the fuel cladding mechanical response under reactivity initiated accident (RIA) and provided recommendations how these methodologies can be used with respect to the parameters to be characterized. As a result of this task a CSNI technical report was drafted, and has been prepared to be published.
Planned activities for the WGFS include:
Spent fuel pools in loss-of-cooling/coolant accident conditions
Leaking fuel impacts and practices
RIA Fuel Codes Benchmark – Volume 1
RIA Fuel Codes Benchmark – Volume 2
NEA/CSNI/R(2013)7/VOL2 (104 Mb)
Nuclear Fuel Safety Criteria technical review (second edition)
Proceedings of the Workshop on Nuclear Fuel Behaviour during RIA
Benchmark calculations on Halden IFA-650 LOCA test results
Safety significance of the Halden IFA-650 LOCA test results
State-of-the-art Report on Nuclear Fuel Behaviour under Reactivity Initiated Accident (RIA) Conditions
NEA/CSNI/R(2010)1, NEA No. 6847, ISBN 978-92-64-99113-2
Nuclear Fuel Behaviour in Loss-of-coolant Accident (LOCA) Conditions
NEA/CSNI/R(2009)15, NEA No. 6846, ISBN 978-92-64-99091-3
Review of High Burn-up RIA and LOCA Database and Criteria
The predecessor of the SEGFSM, the Task Force on Fuel Safety Criteria, prepared the following report, that sets out the results of OECD/CSNI/PWG2 Task Force's work on fuel safety criteria:
Fuel Safety Criteria Technical Review
Last reviewed: 12 June 2015