05000369/LER-1982-013, Forwards LER 82-013/03L-0.Detailed Event Analysis Encl

Forwards LER 82-013/03L-0.Detailed Event Analysis Encl

ML20049J509
Person / Time
Site:	McGuire
Issue date:	02/25/1982
From:	Parker W DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20049J510	List: 05000369/LER-1982-013, Forwards LER 82-013/03L-0.Detailed Event Analysis Encl 05000369/LER-1982-013-03, /03L-0:on 820126,two Upper Head Injection Train a Accumulator Tank Level Switches Miscalibr,Rendering Isolation Valves Inoperable.Caused by Faulty Data Programmed Into Computer Memory.Program Corrected
References
NUDOCS 8203180291
Download: ML20049J509 (4)

LER-1982-013, Forwards LER 82-013/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
3691982013R00 - NRC Website

text

e a

D tJK E POWE H 'CO311%NY l'owen llenmwo we Sourn Cutpen STurr:1, Cn AHINTTie, N. G. una42

> ' ', n b-iij4'l

</ 6 wit uw o. ran= c a, s a.

v.c, e.c., o r.s,

February 25, 1982 ret c. o~r: 4.r. 70 St r ans P.onvctioN 373-4083 sO

's' Mr. James P. O'Reilly, Regional Administrator 7

g U. S. Nuclear Regulatory Commission

..L,'

s Region II N

l 7 jg4'" TO 101 Marietta Street, Suite 3100

t.

Atlanta, Georgia 30303

'f~..r,~[ft yg

//

~

\\.

Re: McGuire Nuclear Station Unit 1

\\ uf Docket No. 50-369

Dear Mr. O'Reilly:

Please find attached Reportable Occurrence Report R0-369/82-13. This report concerns T.S.3.5.1.2, "Each Upper Head Injection Accumulator System shall be operable...".

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

Very truly yours, h

NI v

/

a William O. Parker, Jr.

PBN/jfw Attachment I

cc: Director Records Center Office of Management and Prograrr Analysis Institute of Nuclear Power Operations U. S. Nuclear Regulatory Commission 1820 Water Place Washington, D. C.

20555 Atlanta, Georgia 30339 Mr. P. R. Bemis Senior Resident Inspector McGuire Nuclear Station l

8203180291 820225 PDR ADOCK 05000369 f,. W Q S

PDR 1

$/l

i DUKE POWER COMPANY McGUIRE NUCLEAR STATION REPORTABLE OCCURR3NCE REPORT NO. 82-13 REPORT DATE: February 25,19d2 FACILITY: McGuire Unit 1, Cornelius, NC IDENTIFICATION: A Preventative Maintenance Program Documentation Error Led to the Performance of Cold Shutdown Conditional Maintenance During Power Operation DISCUSSION: On January 26, 1982, while Unit I was operating at 50% reactor power, control room operators were notified that the upper head injection (UHI) accumulator tank level switches for UHI train "A" were out-of-calibration.

Two UHI "A" train isolation valves were subsequently declared inoperable at 1700 and, one hour later, reactor shutdown was :ommenced (load reduction at 10% per hour) in compliance with Technical Specification 3.5.1.2.

This incident was recognized after it was determined that UHI accumulator level switches had been calibrated using the wrong procedure. Prior tc this determi-nation technicians had been working on the annual preventative maintenance program (PMP) requirement, calibration of UHI accumulator tank level switches, which had been scheduled through the generation of work requests. The techni-cians had completed calibration of one switch and were well into the calibration of the other switch when the unexpected excessive amount of adjustment to both instruments (16 inches) caused them to cease the maintenance action and consult their supervisor. As a result of their inquiry it was discovered that the referenced calibration procedure, specified on the work requests, was inappro-priate for the instruments involved.

A special procedure for calibration of the level switches during mode 1, power operation, was prepared, approved, and applied to correct the condition. By 1925 UHI train "A" was determined operable, and a return to 50% power from 35%

power was initiated.

The faulty work requests caused the miscalibration of two safety related instru-ments, and also resulted in the accomplishment of conditional PMP's for which the required condition (cold shutdown) was not satisfied.

A mechanism for prevention of maintenance which is challenging to the Technical Specifications is included in the review and clearance of work requests by Operations Group supervisory personnel.

In this instance the review mechanism failed; therefore, the incident is considered to be due to Personnel Error, as well as Administrative Deficiency due to the PMP failure.

EVALUATION: The two level switches that were miscalibrated function to close two UHI isolation valves. The affected valves are located on opposite accumu-lator discharge headers and both are components of safety related train "A".

The work requests were prepared in December, 1981 to satisfy the annual calibra-tion requirement of the UHI level switches.

" Calibration Procedure for Barton

O Report No. 82-13 Page 2 Model 288 Pressure Switch" was listed as the applicable procedure.

The Barton differential pressure switch is widely used in a variety of applications inclu-ding the UHI accumulator level sensor. However, "UHI Level Switch Calibrations" is the application specific procedure which must be used to adjust these devices.

This procedure is conditional in that the plant must be in cold shutdown, and the particular switch to be calibrated must have its corresponding isolation valve in the closed position. The procedure listed on the work requests conversely makes no such stipulations.

This event is an administrative deficiency occurrence due to the discrepant work requests generated by the computer aided PMP.

It is most probabic that the refer-ence procedure identification error originated in a PMP data submittal that was programmed into the computer memory.

In order to accomplish the icvel switch calibration procedure it was necessary to electrically disconnect the instruments; otherwise, the accumulator discharge isolation valves would have operated during the calibration process. During the maintenance activity, which started at about 1100, the two train "A" isolation valves were alternately divorced from their safety related function control when their associated level evitches were disconnected. Thus the two UH1 train "A" valves were inoperable several hours prior to the determination of this condition (1700, as indicated by the Technical Specification Action Item Logbook).

The failure to correlate UHI level switch calibration with UHI accumulator operability is determined to be personnel error on the part of the Supervisors concerned.

SAFETY ANALYSIS

The functional test on the UHI system verified that one valve per discharge line is ',dequate to isolate the water accumulator from the reactor vessel head.

Isolating with one valve per discharge line would result in a slight increase in the volume of water injected during a blowdown.

Calibrating one of the level switches 16 inches higher than the normal setpoint would slightly decrease the volume of water injected. The smaller the postulated LOCA, the smaller the effect of the disabled and/or miscalibrated switches.

Since the train "B" com-ponents were operable during the event and the train "A" valves were either open and disabled or open and operable but slightly miscalibrated, the capability to isolate the UHI accumulator was continuous and the safety function of the UHI accumulator was never disabled. Safe plant operation and the health and safety of the public were never jeopardized.

CORRECTIVE ACTION

The UHI accumulator was restored to an operable condition through the use of a special procedure developed after the situation occurred.

The programmed PMP data supporting the responsibic work requests has been corrected. A review of PMP work requests has been initiated to ensure that PMP work request supplemental data is appropriate. Emphasis has been placed on infrequently required items which have not yet been scheduled in the station's short operational history. This review will be completed by May 1, 1982.

L

\\

Report No. 82-13 Page 3 An improvement in the administration of the PMP has been implemented which will flag maintenance items which are conditional. This improvement is intended to prevent assignment of work requests when the plant conditional requirements are not present.

l In an unrelated matter involving the improvement of maintenance manpower utili-zation, a control room work request log has been developed and has been in effect since February 8, 1982. Administration of the log requires the acknowledgement of both worker and control room supervisor at the onset and the completion of every work request. This shou?.6 provide for clearer operator awareness of work in progress.

4 7

3 e

4 l

't

+e y n-r- -,

- ~ - -