ML20010B022

Forwards LER 81-113/03L-0.Detailed Event Analysis Encl

ML20010B022
Person / Time
Site:	McGuire
Issue date:	08/05/1981
From:	Parker W DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20010B023	List: ML20010B022 ML20010B026
References
NUDOCS 8108130225
Download: ML20010B022 (2)

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. wi t u AM O. PAR M E R, J R, August 5, 1981 Wcr Persiorm? TtttPwoNE:Anta 704 Strau PnQDucvrow 373-4083 gyuMLFi D s Mr. J. P. O'Reilly, Director ,,

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101 Marietta Street, Suite 310) 2' Atlanta, GA 30303 I.UG 121981

• r' qI p u.s.eccurs ataxAtoss y b """ N Re: McGuire Nuclear Station Unitl Docket No. 50-369 k% -Q A @

Dear Mr. O'Reilly:

Please find attached ILportable Occurrence Report R0-369/81-ll3. This report concerns TS.3.3.2, "The Engineered Safety Feature Actuation System (EFAS) instrumentation channels and interlocks shown in table 3.3-3 shall be operable...".

This incident was considered to be of no significance with respect to the health and safety of the public.

Ver ruly yours,

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William O. Parker, Jr.

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Attachment cc: Director Mr. Bill Lavalee Office of Management and Program Analysis Nuclear Safety Analysis Center U. S. Nuclear Regula*.ory Commission- Post Office Box 10412 Washington, D. C. 20555 Palo Alto, California 94303 16 .*

Ms. M. J. Graham '

Resident Inspector-NRC. "

McGuire Nuclear SL1 tion

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McGUIRE NUCLEAR STATION REPORTABLE OCCURRENCE REPORT NUMBER: 81-113 REPORT DATE: August 5, 1981.

OCCURRENCE DATE: July 6, 1981 FACILITY: McGuire Unit 1, Cornelius, NC IDENTIFICATION OF OCCURRENCE: One channel of the steam line pressure instrumenta-tion for steam generator "D" was declared inoperable.

CONDITIONS PRIOR TO OCCURRENCE: Mode 3, prior to initial criticality.

DESCRIPTION OF OCCURRENCE: On July 6, 1981, routine inspection discovered that some low range (0-60PSIG) pressure gauges on the main steam (SM) lines were pegged high. Suspecting that the gauges were not properly isolated from the SM-line, which was over 200 PSIG, the Operations duty engineer called Instrumentation end Electrical (IAE) to have them check the instrument isolation valves on the affected gauges. During the conversation the technicians wrote down the instrument numbers.

However, pressure transmitter numbers were inadvertently substituted for pressure gauge numbers (lSMPT 5180 for 1SMPG 5180). The technician then isolated the instru-ments on his list, which included a main steam pressure transmitter. Control room operators noticed the corresponding main steam gauge was reading higher than the other channels and declared it inoperable. The affected channel was placed-in the tripped position and a work request was written to repair the defective channel.

The technician assigned to the work request was the same one who had isolated the transmitter. After some discussion with Operations, the technicians realized the error and the transmitr.er was re arned to service.

APPARENT CAUSE OF OCCURRENCE: The error was caused by a misunderstanding between the daty engineer and the technician about which instruments needed-to be isolated.

ANALYSIS OF OCCURRENCE: It is difficult to accurately convey information such as instrument numbers over the phone. The technician went strictly by his list in isclating the instruments, as he had no previous experience working on the SM system. A technician familar with the system would have known that the trans-mitters were essential,,and would also have known that the transmitters were designed for 0-1300 PSIG and could not be overranged at 200-400 PSIG.

SAFETY ANALYSIS: Since the main steam pressure transmitter failed high, it was unavailable for tripping the 2/3 low pressure maiu steam line logic, but two channels remained operable. The logic associated with the transmitter was placed in the tripped position so that the low steam line pressure safety injection trip was blocked. With the signal blocked, the isolation of one channel of "D" SM pressure had no effect on the plant or the health and cafety of the public.

CORRECTIVE ACTION: The immediate corrective action was to place the affected channel of.the SM safety injection trip logic in the tripped position, and then return the transmitter to service. It was also decided that Operations will submit lists of instruments to IAE in the future with signoffs by each instrument listed. Operations and IAE personnel involved were cautioned to be more careful in transmitting this type of information.