Fuel particle failure probabilities and material strengths determined from crush test data

TRISO-coated particles suspended in graphite cylinders are considered to be the main components of the prototypical nuclear fuel of the NP-MHTGR. In view of the observation that the structural integrity of the NP-MHTGR is dependent on the strength of the SiC layer of the coatings, results obtained from a series of crush tests on uniradiated fuel particles were used to estimate the strength of the SiC layer for internal pressure loading. These results were also used to estimate failure probabilities for fuel particles that are lacking an outer pyrolytic carbon layer (OPyC). The strengths of fully coated particles and particles lacking the OPyC layer were compared. Several significant calculation findings were also obtained.