ML20206R494
| ML20206R494 | |
| Person / Time | |
|---|---|
| Site: | 05000087 |
| Issue date: | 08/21/1986 |
| From: | Danker W, Rueter K WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP. |
| To: | Greger L NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| 0438A, 438A, 86-KMR-0045, 86-KMR-45, NUDOCS 8609050446 | |
| Download: ML20206R494 (2) | |
Text
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Nuclear TrainingCenter Electric Corporation ses sniion Bouievara Zionlihnois 60099 (312)872 4585 August 21, 1986 U. S. Nuclear Regulatory Commission Region III Office of Inspection & Enforcement 799 Roosevelt Road Glen Ellyn, IL 60137 Attention: Mr. L. R. Greger
Dear Sir:
This letter constitutes a written report of a reportable occurrence for operation of the Westinghouse Nuclear Training Reactor (NTR), Facility License R-119, Docket No. 50-87. A report was made by telephone to Mr. Don Marksberry, NRC Duty Officer at 1712 on August 14, 1986. Details of the event were also reported to Mr. L. R. Greger of the Region III Office by telephone at 1800 on the same date.
At 1645 on August 14, 1986, during approved operations on the NTR, a spurious electronic signal was received on Channel E which caused the period meter to exceed its trip setpoint of 3.6 seconds but the reactor did not trip. At this time, the NTR was subcritical with the safety rod at 3.5 turns and rods 2 through 5 at less than 1 turn. The failure of the signal on Channel E to result in a reactor trip constitutes a reportable occurrence in accordance with our Technical Specifications section 7.5.1.3: "An engineered safety system component malfunction or other component or system malfunction which could render the reactor safety system incapable of performing its intended safety function." Immediately the duty Senior Reactor Operatcr ordered the reactor to be manually tripped and operations stopped until cause could be determined and the proper authorities notified.
Immediately following the incident, evaluations revealed that the cause of exceeding the period trip setpoint was a spurious electronic spike of short duration ( " 1 sec). No power excursion actually occurred. Power indication on Channels A, E, and F were reading < 0.2 watt. The period on Channel F read infinity. All channels were operability checked as per Technical Specification surveillance requirements and checked satisfactory. At this time, it was concluded that the single failure of Channel E period trip was isolated to the Channel E circuitry. Since only Channel E or F period is -
required by Technical Specification to operate the reactor, Channel E period was removed from service and operations were resumed.
/g h 0438a 8609050446 860821 y 86-KMR-0045 PDR ADOCK 05000087 4Gg 2 S PDR 5 1
. Mr. L. R. Greger
. August 21, 1986 Page 2 Further invest 1gatton of the Channel E circuitry determined the cause of the.
Channel' E malfunction to be the failure of a set of relay contacts in this safety system channel. This set of contacts controls the coil of a reley controlling the magnet voltage of the control rods. The relay has been replaced and the replacement of the defective relay constitutes the necessary action to reduce the probability of reoccurrence.
Sincerely, LMrs -
1 Karen M. Rueter, Manager NTR' Facility 7_ _
Approved By: W. A. Danker .anager-Technical T Ining 0438a 86-KMR-0045
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