05000369/LER-1981-106, Forwards LER 81-106/03L-0.Detailed Event Analysis Encl

Forwards LER 81-106/03L-0.Detailed Event Analysis Encl

ML20009H349
Person / Time
Site:	McGuire
Issue date:	07/30/1981
From:	Parker W DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20009H350	List: 05000369/LER-1981-106, Forwards LER 81-106/03L-0.Detailed Event Analysis Encl 05000369/LER-1981-106-03, /03L-0:on 810702,in Mode 5,operating Light on Panel for EMF-51-B Would Not Remain Illuminated.Probably Caused by Design Problem in Amplifier/Readout Module (Ga Co Model RP-2C)
References
NUDOCS 8108100001
Download: ML20009H349 (3)

LER-1981-106, Forwards LER 81-106/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
3691981106R00 - NRC Website

text

o e

DUKE POWER COMPAN [O.7-

[

mugo REr

'l

~, l /.,

~ PowEH UtnwlNG

~

422 SouTn Cnt:ucu STHEET, CnAHwTTE, N. C. et..ua

[

WI W AM O.PARKE,

R.

v.cr ParsecrHT July 30, 1981 Tctc~o~c ^aca ve4 Sycaw Paoou:Tiote 373-4083

• tl h p

N Mr. J. P. O'Reilly, Director f

. f%

Q D

U. S. Nuclear Regulatory Commission 1

9 Region II gg-

,,ij(; Q 7198 > [

1 r

101 Marietta Street, Suite 3100 saa m se ^

Atlanta, Georgia 30303

• • • ,eo a,ssus G f.

pf,\\

Re: McGuire Nuclear Station Unit 1

/

Docket No. 50-369 g

Dear Mr. O'Reilly:

Please find attached Reportable Occurrence Report R0-369/81-106. This report concerns Technical Specification 3.3.3.1, "The radiation monitoring instrumentation channels shown in Table 3.3-6 shall be operable with their alarm / trip setpoints within the specified limits. This incident was considered to be of no significance with respect to the health and safety of the public.

Very truly yours, h)

""/

g William O. Parker, Jr.

PBN/krh Attachment cc:

D'

.or Mr. Bill Lavelee

'ce of Management and Program Analysis Nuclear Safety Analysis Center U.

. Nuclear Regulatory Commission Post Office Box 10412 Washington, D. C.

20555 Palo Alto, California 94303 Ms. M. J. Graham Resident Inspector-NRC McGuire Nuclear Station fh salt 8108100001 810730 PDR ADOCK 05000369 S

PDR

McGUIRE NUCLEAR STATION REPORTABLE OCCURRENCE REPORT NUMBER:

81-106 REPORT DATE: July 30, 1981 OCCURRENCE DATE: July 2, 1981 FACILITY: McGuire Nuclear Station; Unit 1, Cornelius, NC IDENTIFICATION OF OCCURRENCE: The containment area radiation monitoring instru-ment (EMF 51-B) was declared inoperable.

CONDITIONS PRIOR TO OCCURRENCE: Mode 5, Cold Shutdown DESCRIPTION OF OCCURRENCE:

It was observed in the control room that the

" Operating" light would not remain illuminated on the panel for EMF-51-B.

The Shift Supervisor declared the system inoperable and requested that the instrument be repaired.

This was a reportchle incident pursuant to Technical Specification 3.3.3.1.

APPARENT CAUSE: The failure of the operating light appears to be the result of a design problem in the Amplifier / Readout Module (General Atomics Co., Model RP-2C) located in the control room.

It is believed that a transistor within the input amplifier becomes saturated because a resistor is missing from the circuit.

This results in a temperature dependent drift of the instrument off the zero end of the scale.

ANALYSIS OF OCCURRENCE:

EMi-51-B is a high radiation monito'r that was installed as part of a design package to comply with new regulations and requirements following the incident at TMI-2.

It was initially calibrated and functionally tested on June 19, 1981.

Approximately one week later, personnel in the control room began experiencing problems with keeping the " operating" light illuminated.

On July 1, a work request was initiated which included having EMF-51-B examin.id and calibrated.

This EMF was subsequently declared inoperable at 1215 hours0.0141 days <br />0.338 hours <br />0.00201 weeks <br />4.623075e-4 months <br /> on July 2, and the necessary repairs made the same day.

The light again failed and had to be adjusted on July 6th, 8th, and 9th. The system was put back into service and declared operable at 1800 hours0.0208 days <br />0.5 hours <br />0.00298 weeks <br />6.849e-4 months <br /> on July 9.

On July 10, the instrument failed in the same manner as before, and another work request was initiated to make the necessary repairs.

It is anticipated that this will be an on-going problem until the vendor deter-mines and authorizes a corrective modification to this instrument.

In conver-sations with a vendor representative, it was learned that other utilities who had installed this same type of equipment were experiencing the same difficulty.

i Report Number 81-106 Page 2 1

l

- CORRECTIVE ACTION: The calibration of EMF-51-B was checked and the necessary repairs made.

Later, another work request was initiated to make the necessary adjustments until a resolution from the vendor can-be implemented. The vendor, General Atomics Co., was notified'and are currently-investigating this design problem.

SAFETY ANALYSIS

EMF-51-B is a high range radiation monitor (1CJ-10 Rad /hr) ' to 8

detect massive amounts of radiation in containment. The failure of the "oper-ating" light to be illuminated has no affect..n the actual operability of the instrument. Had an accident involving high doses of radiation occurred, its magnitude could have been determined. Thus, neither the safe operation of the plant or the health and safety of the public were affected by this incident.

I l

l l

I