Expert system for surveillance and diagnosis of breach fuel elements
AssigneeThe United States of America as represented by the United States Department of Energy
InventorKenny C. Gross
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Abstract
An apparatus and method are disclosed for surveillance and diagnosis of breached fuel elements in a nuclear reactor. A delayed neutron monitoring system provides output signals indicating the delayed neutron activity and age and the equivalent recoil areas of a breached fuel element. Sensors are used to provide outputs indicating the status of each component of the delayed neutron monitoring system. Detectors also generate output signals indicating the reactor power level and the primary coolant flow rate of the reactor. The outputs from the detectors and sensors are interfaced with an artificial intelligence-based knowledge system which implements predetermined logic and generates output signals indicating the operability of the reactor.
Claims15
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.
In a nuclear reactor having a core comprised of a plurality of cladded fuel elements, a coolant having a primary flow over said cladded fuel elements said elements including fissionable fuel which emits delayed neutrons (DN) as part of a nuclear chain reaction a method of diagnosing the status of said reactor, when said reactor has a breached fuel element, comprising the steps of:
- monitoring changes in DN activity with DN activity detecting means and generating an output signal in response thereto;
- continuously monitoring changes in the, age of DN with DN age monitoring means and generating an output signal in response thereto, said DN age comprising the sum of a transit time, T.sub.tr, and a hold up time T.sub.h ;
- measuring the equivalent recoil area (ERA) of a breach in the cladding of said fuel elements with ERA measuring mean and generating an output signal in response thereto;
- testing the operability of said DN activity monitoring means, said DN age monitoring means and said ERA measuring means with operability validation means and generating output signals indicating the operability thereof;
- measuring the power of said reactor and generating an output signal in response thereto;
- measuring the primary coolant flow rate and generating an output signal in response thereto;
- determining and indicating the status of said reactor including whether said reactor should be scrammed, manually shut down, continue to operate or whether an alarm status should be set from predetermined combinations of output signals, said predetermined combination accounting for a nonconstant DN age.
Dependencies are inferred from the claim text.