ML17261A188

LER 80-004/01T-0:on 800506,during post-installation Test of Reactor Vessel Head Vent,Dc Power Switches for Both Trains of Low Temp Overpressurization Protection Found in Off Position W/No RCS Vent Open.Cause Unknown

ML17261A188
Person / Time
Site:	Ginna
Issue date:	05/19/1980
From:	Peck C ROCHESTER GAS & ELECTRIC CORP.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML17249A916	List: ML17249A915 ML17261A188
References
LER-80-004-01T, LER-80-4-1T, NUDOCS 8005230528
Download: ML17261A188 (6)

Text

NRC FQRM 368 U. S. NUCLEAR REGULATORY COMMISSION I7-77L 80-004/01T-0 rp LICENSEE EVENT REPORT (CAR 1264)

CONTROL BLOCK: Q1 (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION)

I 6 toD1 j 7 8 9 N Y R E LICENSEE CODE G 1Q20 14 15 0 0 0 0 0 LICENSE NUMBER 0 0 0 25 Q3 26 4 1 1 LICENSE TYPE 1 1 30 QE~QE 57 CAT 56 CON'T

~o ~LLQB 0 5 0 0 0 2 4 4 7 0 5 0 6 S 0 B 0 5 1 9 8 0 QQB SOURCE 7 8 60 61 DOCKET NUMBER 69 EVENT DATE 74 75 REPORT DATE 80 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES QIO

~o During post installation test of reactor vessel head vent, DC power switches for both trains of low temp. overpressurisation protection (OPPS) were found in OFF position with no RCS vent open. (T . S . 3 . 1 5) System had been charged and operable as logged earlier, noted open 10 hrs. later during inspection for above test, closed for test and

~os reoPened. Switches were reclosed after notification of condition. Sl um s had been locked out and loop-SG temps ~ were nearly equal so that potential causes of overpres-

\

sure transients were minimized and no hazardous consequences resulted .

7 8 9 80 SYSTEM CAUSE CAUSE COMP. VALVE CODE CODE SUBCODE COMPONENT CODE SUBCODE SUBCODE

[oO~) ~CB QII X QI2 ~Z QI3 C K T B R K QI4 ~E QIs ~Z QIs 7 8 9 10 11 12 13 16 19 20 SEQUENTIAL OCCURRENCE REPORT REVISION Q17 LERiRO REPORT ACTION FUTURE EVENT YEAR

~80 21 22 EFFECT

~

23 SHUTDOWN

~00 24 REPORT NO.

4 26

~~

27

~01 28 ATTACHMENT CODE 29 NPRDP TYPE

~T 30 PRIME COMP.

~

31 NO.

32 0

COMPONENT TAKEN ACTION 33 QI8 ~+QIE 34 ON PLANT

~ZQEO 35 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS Q2I METHOD

~ZQ2 36 37 HOURS +2>

0 40

~

SUBMITTED 41 Q23 FORM SUB.

pJQ24 42 SUPPLIER pJQ25 43 44 MANUFACTURER 1 2 0 47 Q28 o Shift personnel were guesttoned on DC panel key; station hold record was checked, I

with no record of key or hold assignment. Procedure 0-7 Alignment and Operation of the Reactor Vessel Overpressure Protection System was amended to add verification that DC power switches are closed prior to putting OPPS in service.

4 7 8 9 80 5

FACILITY STATUS

~GQ28 ~00

% POWER 0 Q28 OTHER STATUS NA

~ METHOD OF DISCOVERY

~CQ3I Sound of OPPS venting DISCOVERY DESCRIPTION Q32 after vent test 7 8 9 10 12 13 44 45 80 ACTIVITY CONTENT RELEASED OF RELEASE

~Z Z AMOUNTOF ACTIVITY NA Q NA LOCATION OF RELEASE Q QQQ 8 9 Q33 10 Q3 7 11 45 80 PERSONNEL EXPOSURES NUMBER TYPE DESCRIPTION Q39 2 ~00 0 Q32 ~ZQ38 NA 7 8 9 11 12 80 INJURIES 13'ERSONNEL 8 ~00 NUMBER 0 Q4o DESCRIPTION Q NA 7 8 9 11 12 80 LOSS OF OR DAMAGE TO FACILITY TYPE DESCRIPTION Q43 Z Q42 NA 8 9 10 80 PUBI.ICITY 5 0 05 2 3 0 P2-)4I NRC USE ONLY

~>>

7 8

~%Q44 9 10 NA 68 69 80 o o

0 NAME OF PREPARER Carl H. Peck PHDNE 3 1 5/524-4446 a

Attachment tc LER l04/01T-0 Rochester Gas and Electric Corporation R. E. Ginna Nuclear Power Plant, Unit No. 1 Docket No. 50-244 On May 6, 1980 during performance of post installation hydrostatic pressure testing of the reactor vessel remotely operated head vent system it was found that the DC switches which supply power to both trains of the low temperature overpressurization protection control of the pressurizer power operated relief valves were found in the OFF position, with no Reactor Coolant System vent open as required by Technical Specification 3. 15 when the system temperature is less than 330 F. This was discovered when the Operations Supervisor, during a tour of containment, investigated the sound of venting from the nitrogen system for the power operated relief valves.

A review of previous activities showed that at 0115 hours0.00133 days <br />0.0319 hours <br />1.901455e-4 weeks <br />4.37575e-5 months <br /> that morn-ing procedure S-29.2 "Charging the Reactor Vessel Overpressure Protection System Accumulators with N2" was performed. The DC supply switches must be closed to allow the nitrogen to charge these accumulators. At 1115 hours0.0129 days <br />0.31 hours <br />0.00184 weeks <br />4.242575e-4 months <br /> a member of the Results and Test Group, in preparing for the hydrostatic pressure test of the newly installed head vent system, noted that these switches were open, but was not aware that the modification being tested had been added to the same source of power supplying the overpressure pro-tection system. At 1400 hours0.0162 days <br />0.389 hours <br />0.00231 weeks <br />5.327e-4 months <br /> a member of the Results and Test Group inserted fuses and closed the switches in order to perform the hydrostatic pressure test of the head vent system, and after completion reopened the switches and removed the fuses. This resulted in venting of two small nitrogen accumulators in the overpressure protection system, heard by the Operations Supervisor. After he notified the Control Room of the condition, the system was restored to operability, and at that time it became known that both the overpressure protection system and the head vent solenoid valves are powered by the same DC switches.

The low temperature overpressure protection system was provided to insure that temperature-pressure requirements in consideration of reactor vessel fracture toughness are not exceeded. In further recognition of these requirements the control switches for the safety injection pumps were in the PULL-STOP position and the reactor coolant-steam generator temperature differences were virtually zero so that potential causes of overpressure transients were minimized and no hazardous consequences resulted. The DC power switches would have been returned to the correct position upon completion'of work on the head vent system.

The personnel on the night shift and day shift were questioned about who was given the key for the DC panel. The only persons who they remem-bered giving the key to were the two test individuals mentioned above. How-ever, since the key is common to several electric panels, it is possible that other keys are available. The operators do not recall seeing other personnel in the DC panels.

Attachment tc LER 804/01T-0 The station hold records were checked. The switches were restored to service on May 2, 1980, with no other holds performed on this system since that date.

Procedure 0-7 Alignment and Operation of the Reactor Vessel Over-pressure Protection System was modified to require verification that the DC power switches are closed prior to putting the system into service. The locks for the DC panels will be changed in order to limit the distribution of keys to prevent recurrence.

4