05000269/LER-1982-008, Forwards Updated LER 82-008/01X-1.Detailed Event Analysis Encl

Forwards Updated LER 82-008/01X-1.Detailed Event Analysis Encl

ML20058G975
Person / Time
Site:	Oconee
Issue date:	07/23/1982
From:	Parker W DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20058G980	List: 05000269/LER-1982-008, Forwards Updated LER 82-008/01X-1.Detailed Event Analysis Encl
References
NUDOCS 8208030460
Download: ML20058G975 (3)

LER-2082-008, Forwards Updated LER 82-008/01X-1.Detailed Event Analysis Encl

Event date:
Report date:
2692082008R00 - NRC Website

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,3. ,0 Mr. James P. O'Reilly, Regional Administrator U. S. Nuclear Regulatory Commission Region II 101 Marietta Street, Suite'3100 Atlanta, Georgia 30303 Re: Oconee Nuclear Station Docket No. 50-269

Dear Mr. O'Reilly:

Please find attached Reportable Occurrence Report R0-269/82-08, Revision 1, which contains updated information about the Analysis of Occurrence and Corrective Action. This report describes an incident which is considered to be of no sig-nificance with respect to its effect on the health and safety of the public.

Please replace the previous report with the attached revision.

i Very truly yours, l

Mw 0.

.Afilliam O. Parker, Jr.

t 4 JFN/php Attachment l

cc: Document Control Desk U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Records Center Institute of Nuclear Power Operations

1820 Water Place Atlanta, Georgia 30339 Mr. W. T. Orders NRC Resident Inspector Oconee Nuclear Station Mr. Philip C. Wagner Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C. 20555 QFygg c B208030460 020723 PDR ADOCK 05000269 S

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Duke Power Company Oconce Nuclear Station Unit 1 Report Number: R0-269/82-08, Revision 1 Report Date: July 6, 1982 Occurrence Date: March 23, 1982 Facility:' Oconee Unit 1, Seneca, South Carolina Identification of Occurrence: Missing test tee cap in penetration room Conditions Prior to Occurrence: Hot shutdown Description of Occurrence: On March 23, 1982, air was found flowing into the Reactor Building through an instrument line test tee in penetration WB-13. The cap for the test tee was missing, thereby allowing flow from the Reactor Building into the penetration room. This constitutes a violation of Technical Specifica-tion 3.6.1.

Apparent Cause of Occurrence: The apparent cause of this occurrence is personnel error, in that the instrument line test tee cap was not properly reinstalled upon completion of calibration testing during the unit refueling outage in July 1981.

Analysis of Occurrence: The test tee with the cap removed creates a 0.19 inch ID leak path in the Reactor Building. Using a pressure versus time calculation for a LOCA, the resultant leak rate via this path is significantly less than the Reactor Building design leak rate of 0.25 weight-percent per day. Leakage from the Reactor Building under these conditions would be filtered by the Penetration Room Ventilation System and radiation levels would be monitored on RIA-51 gaseous radiation monitor. There is no evidence indicating that radiation levels in the penetration room during unit operation in February and March 1982 were above normal levels experienced during previous unit operation.

i l The subject incident affected the performance of one of three independent channels of one of the two redundant RB spray trains. It did not affect the performance or operation of any other instrumentation or safety system. The RB spray system is a safety system designed to limit the RB pressure to within the design limit during accidents involving blowdown of mass and energy into the RB (LOCA and accidents involving secondary system break within the RB). It is also considered to be useful in scrubbing the radioactivity from the RB atmosphere during the post-accident phase of a LOCA. With respect to limiting the RB pressure, the RB cooling system, which is independent of the spray system, is fully capable of limiting the RB pressure to within the design limit, irrespective of the availability of the spray system.

Each of the two redundant RB spray trains is automatically actuated upon tripping of two of three redundant channels. The nominal trip setpoint for each channel is 10 psig with a required trip actuation (as required by Technical Specification and safety analysis assumptions) of 30 psig. The subject incident caused Pressure

r Switch IPS-22 not to trip at the nominal setpoint of 10 psig and would have required a larger input pressure to trip. This situation rendered this channel inoperable within the traditional definition of channel operability. However, it has now been determined that the channel would have indeed tripped at a pres-sure of approximately 22 psig, well within the required setpoint of 30 psig. This determination is based on recent tests conducted on the same channel of a similar unit simulating the as-found condition and applying a gradually increasing pres-sure on the sensing line. During this test the channel repeatedly tripped at approximately 22 psig; therefore, this incident did not degrade the RB spray system nor did it significantly degrade the function of the channel. It is also pointed out that even if the channel were inoperable, the RB Spray System can still accommodate a single failure and achieve system design function. Thus, it is considered that this incident had no significant effect on the health and safety of the public.

Corrective Action: The immediate corrective action identified the source of the air leak as a missing cap for the test tee for 1PS22. The test tee was capped, thereby reestablishing containment integrity. An investigation was performed on the instrumentation associated with the reactor protective system and engineering safety feature systems to assure that all instruments were properly in service.

The investigation revealed no additional abnormalities.

As a result of nrocedural deficiencies identified early in January 1982, the Oconee I&E Engineer issued a letter on January 15, 1982 requiring independent (second party) verification, in an effort to ensure that for all future tests, equipment would be returned to normal and properly documented. This independent verification has someone unconnected with the testing come behind the tester to check and confirm that all of the required procedures were completed and that the system was properly returned to an operable condition. On March 26, 1982, the Oconee Station Manager issued a letter again emphasizing the need for a more improved checking system and requiring specific identification of each item that may have been removed from normal so each can be rechecked.

The changes in verification requirements were presented to all affected personnel with emphasis on the necessity for ensuring proper equipment status for safe operation of the plant.