Patent ID: 8737557

Claim:
A method to assess light water reactor fuel integrity after a given time of operation of the reactor, the method comprising: granting access in a nuclear reactor fuel pool to at least one of a discharged fuel rod and a nuclear fuel assembly, wherein the at least one discharged fuel rod or nuclear fuel assembly experienced a heat flux; determining the heat flux experienced by the at least one fuel rod or nuclear fuel assembly; measuring a thickness of CRUD on the at least one fuel rod or nuclear fuel assembly; measuring a thickness of oxide on the at least one fuel rod or nuclear fuel assembly; determining a maximum possible heat flux for the at least one fuel rod or nuclear fuel assembly for a position of the at least one fuel rod or nuclear fuel assembly in a nuclear reactor on a life of the fuel assembly; determining a maximum possible CRUD deposit for the at least one fuel rod or nuclear fuel assembly in the nuclear reactor; determining a maximum possible oxide thickness for the at least one fuel rod or nuclear fuel assembly in the nuclear reactor; calculating a fuel condition index of the at least one fuel rod or nuclear fuel assembly in a calculation comprising calculating a ratio of the experienced heat flux to the maximum possible heat flux, calculating a ratio of the CRUD measured thickness to the maximum possible CRUD thickness, and calculating a ratio of the measured oxide thickness to the maximum possible oxide thickness; comparing the fuel condition index to an index constant; and removing the at least one of the fuel rod and the nuclear fuel assembly from operation when the fuel condition index is greater than the index constant.