Patent Document ID: 4803040
Application ID: 07146559
Patent Flag: 1

Claim One:
1. In a nuclear reactor having a core comprised of a plurality of cladded fuel elements, a coolant having a primary flow through the core over said cladded fuel elements, said fuel elements including fissionable fuel which emits delayed-neutrons (DN) as part of a nuclear chain reaction, a breached fuel element diagnostic apparatus comprising: monitoring means for measuring the coolant primary flow rate and reactor power and generating output signals in response thereto; delayed-neutron monitoring system (DNMS) means for measuring the equivalent recoil area (ERA) of a breach in the cladding of said fuel elements and for continuously monitoring the DN age and DN activity and generating output signals in response thereto, said DN age comprising the sum of a transit time, T.sub.tr, and hold-up time, T.sub.h ; operability validation means for testing the operability of the components of said DNMS means and generating output signals indicating the operability of said components; and a knowledge system comprising a factual knowledge base, a judgment knowledge base and means for said judgmental knowledge base to access said factual knowledge base, said judgmental knowledge base receiving, as input signals, the output signals from said monitoring means, DNMS means and operability validation means, said judgmental knowledge base comprising means for determining the operability of said reactor from a predetermined combination of judgmental knowledge base input signals, said predetermined combination accounting for a nonconstant DN age, and generating output signals in response thereto.