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 Title: |
US4582672:
Method and apparatus for preventing inadvertent criticality in a nuclear fueled electric powering generating unit
[ Derwent Title ]
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| Country: |
US United States of America
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| Inventor: |
Tuley, Jr., Charles R.; Penn Township, Westmoreland County, PA
Bauman, Douglas A.; Murrysville, PA
Feilchenfeld, Michal M.; Pittsburgh, PA
Greenberg, Lesley; Monroeville, PA
Neuner, James A.; Gibsonia, PA
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| Assignee: |
Westinghouse Electric Corp., Pittsburgh, PA
other patents from WESTINGHOUSE ELECTRIC CORP. (625115) (approx. 12,106)
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| Published / Filed: |
1986-04-15
/ 1982-08-11
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| Application Number: |
US1982000407231
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| IPC Code: |
Advanced:
G21C 9/00;
G21C 17/00;
G21D 3/06;
Core:
G21D 3/00;
more...
IPC-7:
G21C 17/00;
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| U.S. Class: |
Current:
376/254;
376/215;
376/255;
376/328;
976/DIG.139;
976/DIG.299;
Original:
376/254;
376/255;
376/215;
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| Field of Search: |
376/254,255,259,214-218
250/390-392
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| Priority Number: |
| 1982-08-11 |
US1982000407231 |
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| Abstract: |
An inadvertent approach to criticality in a nuclear fueled electric power generating unit is detected and an alarm is generated through on-line monitoring of the neutron flux. The difficulties of accurately measuring the low levels of neutron flux in a subcritical reactor are overcome by the use of a microcomputer which continuously generates average flux count rate signals for incremental time periods from thousands of samples taken during each such period and which serially stores the average flux count rate signals for a preselected time interval. At the end of each incremental time period, the microcomputer compares the latest average flux count rate signal with the oldest, and preferably each of the intervening stored values, and if it exceeds any of them by at least a preselected multiplication factor, an alarm is generated. The interval and multiplication factor are chosen such that an alarm is generated early enough in the event to provide adequate time for an automatic system or the operator to take action which prevents the reactor from going critical yet minimizes the likelihood of a spurious response. As applied to a pressurized water reactor system, boron dilution events are detected in time that the chemical and volume control system can be isolated and the valves for the refueling water storage tank can be opened to inject highly borated water into the reactor coolant system to keep the reactor subcritical.
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| Attorney, Agent or Firm: |
Abeles, Daniel C. ;
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| Primary / Asst. Examiners: |
Cangialosi, Salvatore;
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| Maintenance Status: |
E2 Expired Check current status
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| INPADOC Legal Status: |
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| Designated Country: |
BE CH DE IT LI SE
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| Family: |
Show 25 known family members
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First Claim:
Show all 19 claims |
What is claimed is:
1. A method of detecting an inadvertent approach to criticality in a nuclear fueled electric power generating unit comprising the steps of:
- generating an instantaneous neutron flux count rate signal representative of the instantaneous neutron flux in the reactor at a level of reactivity of about 10-4 percent reactor power and below;
- generating from the instantaneous neutron flux count rate signal first and second average flux count rate signals representative of the average neutron flux count rate signal over first and second incremental time periods spaced apart in time by a preset time interval including sampling the instantaneous neutron flux count rate signal repetitively during said incremental time periods and generating said first and second average flux count rate signals as the average of the samples taken during the respective intervals; and
- comparing said first and second average flux count rate signals and generating an alarm when the second average flux count rate signal exceeds the first average flux count rate signal by at least a preselected multiplication factor.
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| Background / Summary: |
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| Drawing Descriptions: |
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| Description: |
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| Forward References: |
Show 11 U.S. patent(s) that reference this one
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