Failure of TRIGA fuel cladding at the Berkeley research reactor

Conference · Tue Jul 01 04:00:00 EDT 1986

OSTI ID:21157012

Denton, Michael M; Lim, Tek H ^[1]

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1. Department of Nuclear Engineering, University of California, Berkeley, CA (United States)

Following a long maintenance shutdown during which a fission chamber was refurbished and a compensated ion chamber replaced, concentrations of radioisotopes were detected in the reactor-room air on a Constant (CAM) after two and a half hours of full-power operation. Following test lead to identification of three fission-product gasses in the reactor room air: Kr{sup 85m}, Kr{sup 87} , and Kr{sup 88} . Conservative estimates indicated the maximum concentrations of all fission gasses to be about 1.1x10{sup -8} {mu}Ci/ml with a total release of less than 1 mCi. It was concluded that the gasses come from a leaking fuel element. Three old, instrumented elements with defective thermocouples were removed first and the reactor was tested at full-power. No abnormal activities were detected during or following the operation. Each of the suspected fuel elements are instrumented with leadout tubes extending 15 feet to above the pool surface. This suggests some possible causes for the cladding failure. First, flexing due to daily movement of the core could have weakened the tube/cladding connection. Secondly, the cladding itself may have been damaged during maintenance procedures requiring removal of the elements or repositioning of the leadout tubes.

• Research Organization: TRIGA Reactors, GA Technologies Inc., San Diego, CA (United States); Texas A and M University, College Station, TX (United States)
• OSTI ID: 21157012
• Report Number(s): INIS-US--09N0265; TOC--18
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
CLADDING
FISSION CHAMBERS
FISSION PRODUCTS
FUEL ELEMENT FAILURE
FUEL ELEMENTS
KRYPTON 85
KRYPTON 87
KRYPTON 88
MAINTENANCE
REACTOR OPERATION
SHUTDOWN
TUBES
UCBRR REACTOR