Failure Thresholds of High Burnup BWR Fuel Rods under RIA Conditions

• Published in: Journal of nuclear science and technology 2004-01, Vol.41 (1), p.37-43
• Main Authors: NAKAMURA, Takehiko, FUKETA, Toyoshi, SUGIYAMA, Tomoyuki, SASAJIMA, Hideo
• Format: Article
• Language: English
• Subjects: accidenty; Applied sciences; BWR type reactors; Energy; Energy. Thermal use of fuels; Exact sciences and technology; Fission nuclear power plants; fuel failure threshold; Fuels; high burnup BWRfuel; Installations for energy generation and conversion: thermal and electrical energy; NSRR; Nuclear fuels; Preparation and processing of nuclear fuels; reactivity-initiated
• ISSN: 0022-3131; 1881-1248
• DOI: 10.1080/18811248.2004.9715455

Transient deformation of high burnup boiling water reactor (BWR) fuel rods was measured and failure limit was examined under simulated reactivity-initiated accident (RIA) conditions. Brittle cladding failure occurred at a small hoop strain of about 0.4% during an early phase of the pulse irradiation tests at the Nuclear Safety Research Reactor (NSRR). Strain rates were in an order of tens %/s at the time of the failure. Comparison of the results with thermal expansion of pellets suggested that the cladding deformation was caused by thermal expansion of the pellets. In other words, the influence of fission gases in the pellets was small in the early phase deformation. Separate effect tests were conducted to examine influence of the cladding temperature on the cladding failure behavior. Influence of the pulse width on the failure threshold was discussed in terms of the strain rate, magnitude of the deformation and temperature of the cladding for high burnup BWR fuel rods under the RIA conditions.