05000311/LER-1982-059, Forwards LER 82-059/03L-0.Detailed Event Analysis Encl

Forwards LER 82-059/03L-0.Detailed Event Analysis Encl

ML20062G870
Person / Time
Site:	Salem
Issue date:	08/04/1982
From:	Midura H Public Service Enterprise Group
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20062G872	List: 05000311/LER-1982-059, Forwards LER 82-059/03L-0.Detailed Event Analysis Encl
References
NUDOCS 8208130214
Download: ML20062G870 (4)

LER-1982-059, Forwards LER 82-059/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
3111982059R00 - NRC Website

text

,

i O PSEG Public Service Electric and Gas Company P.O. Box E Hancocks Bridge, New Jersey 08038 Salem Generating Station August'4, 1982 Mr.

R.

C.'Haynes Regional Administrator USNRC Region 1 631 Park Avenue King of Prussia, Pennsylvania 19406

Dear Mr. Haynes:

LICENSE NO. DPR-75 DOCKET'NO.-50-311 REPORTABLE OCCURRENCE 82-059/03L Pursuant to the requirements of Salem Generating Station Unit No.

2, Technical Specifications, Section 6.9.1.9.b, we are submitting Licensee Event Report for Reportable Occurrence 82-059/03L.

This report is required within thirty (30) days of the occurrence.

Sincerely yours,

. [ !':

4%

H.

J.

Midura General Manager -

Salem Operations RF:ks CC:

Distribution 8200130214 820804 PDR ADOCK 05000g l' 5 }

a T he Energy People

% 2189 (2GM) 1181

o i

Report Number:

82-059/03L Report Date:

08-04-82 Jccurrence Date:

07-06-82 Facility:

Salem Generating Station, Unit 2 Public Service Electric & Gas Company Hancocks Bridge, New Jersey 08038 IDENTIFICATION OF OCCURRENCE:

Steam Generator Relief Valve 23MS15 - Inoperable.

This report was initiated by Incident Report 82-173.

CONDITIONS PRIOR TO OCCURRENCE:

Mode 2 - Rx Power 2% - Unit Load 0 MWe.

DESCRIPTION OF OCCURRENCE:

At 2320 hours0.0269 days <br />0.644 hours <br />0.00384 weeks <br />8.8276e-4 months <br />, July 6, 1982, during the process of warming up main steam lines, a safety valve on No. 23 Steam Generator (S/G) lifted below its setpoint.

At the time of occurrence Tave was 550 F and S/G pressures were approximately 1020 PSIG.

The valve failed to reseat; it was not determined at the time of the occurrence which safety was involved.

The Control Room Operator started to cooldown the Reactor Coolant System (RCS) in order to lower S/G pressure and reseat the safety.

The power operated relief valves of the unaffected S/G's were used in an attempt to keep generator pressures within 100 PSI and prevent a safety injection.

At 2340 hours0.0271 days <br />0.65 hours <br />0.00387 weeks <br />8.9037e-4 months <br />, with the differential pressure approaching 100 PSI, and with S/G levels and Tave decreasing, the operator commenced insertion of the control rods.

At 2340 hours0.0271 days <br />0.65 hours <br />0.00387 weeks <br />8.9037e-4 months <br />, as a result of increased make-up to the S/G'c, the Auxiliary Feedwater Storage Tank (AFST) level dropped below the Technical-Specification limit of 200,000 gallons.

The tank was declared inoperable 7and Action Statement 3.7.1.3.a was entered.

A reactor trip due to a No. 23 S/G Low Low Level signal, occurred at 2342 hours0.0271 days <br />0.651 hours <br />0.00387 weeks <br />8.91131e-4 months <br />.

No. 23 Auxiliary Feedwater Pump started several minutes later, associated with a low level on No. 24 S/G; the low levels resulted from the RCS cooldown and S/G Level shrink.

Pressurizer level was decreasing due to the outsurge involved, and at 2345 hours0.0271 days <br />0.651 hours <br />0.00388 weeks <br />8.922725e-4 months <br />, letdown isolation and heater deenergization occurred.

The Volume Control Tank (VCT) level was lowered by increased charging and letdown isolation until 2348 hours0.0272 days <br />0.652 hours <br />0.00388 weeks <br />8.93414e-4 months <br />, when the charging pump suction shifted to the gefueling Water Storage Tank (RWST).

At 2354 hours0.0272 days <br />0.654 hours <br />0.00389 weeks <br />8.95697e-4 months <br />, with Tave 522 F and S/G pressures approximately 830 PSIG, the safety valve finally reseated.

An immediate investi-gation revealed that the problem involved Safety Valve 23MS15.

The setpoint of the valve in 1070 PSIG.

The manual actuator spindle nut was found jammed between the spindle and the actuator cap, and the spindle threads were damaged.

The valve was declared inoperable, and at 0001 hours1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />, July 7, 1982, Action Statement 3.7.1.1.a was entered.

Pregsurizer level was restored and letdown reinitiated.

With Tave 520 F and S/G pressures 800 PSIG, the plant was in a stable condition.

VCT level returned to normal, and the RCS was subsequently borated to 405 ppm.

The minimum level reached on the AFST during the transient was 185,000 gallons.

DESIGNATION OF APPARENT CAUSE OF OCCURRENCE:

The low AFST level was due to the delay inherent with manual initiation of make-up flow from the Demineralized Water System and to increased feeding of the S/G's required by the transient.

The reason for the premature actuation and failure of Safety Valve 23MS15 has not been determined.

Further investigation of the problem will be made during the next outage of extended duration, when the failed valve can be removed and inspected.

ANALYSIS OF OCCURRENCE:

The operability of the AFST ensures sufficient water is available to maintain the Reactor Coolant System in hot standby for 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> concurrent with steam discharge to the atmosphere and complete loss of offsite power.

A redundant water supply was available, j

however, by cross-connection to the fire protection and domestic j

water storage tanks.

I l

The main steam line code safety reliefs ensure that the secondary l

system pressure will be less than 110% of design pressure during a turbine trip from 100% power and an assumed loss of condenser heat sink.

Operation may continue with an inoperable safety valve, provided maximum power level is reduced in a timely fashion.

As noted, the unit was already in hot standby and the failure would not have prevented operation of the relief in the event of a steam pressure transient.

Since, in both cases, the safety functions involved were already provided for by existing features or conditions, no risk to the health or safety of the public was involved.

The incident consti-tuted operation in a degraded mode permitted by a limiting conditon for operation and is reportable in accordance with Technical i

l Specifications 6.9.1.9.b.

L

j-Action Statement 3.7.1.3 requires:

With the AFST inoperable, within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> either restore the AEoT to operable status or be in hot shutdown within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />; or demonstrate the operability of a backup supply to the auxiliary feedwater pumps and restore the AFST to operable status within 7 days or be in hot shutdown within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

Action Statement 3.7.1.1.a requires:

With a main steam line code safety valve inoperable, operation'in Modes 1, 2,

and 3 may continue provided that, within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />, either the inoperable valve is restored to_ operable status or the Power Range Neutron Flux High trip setpoint is reduced to 87%

of rated thermal power; otherwise, be in at least hot standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in cold shut-down within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

CORRECTIVE ACTION

Make-up to the AFST was initiated, and at 0024 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, the contained volume was in specification.

The tank was declared operable, and Action Statement 3.7.1.3.a was terminated.

Design Change Request 2EC1252, installing remote controls for AFST make-up in the Control Room, is scheduled for completion during the next refueling outage.

Valve 23MS15 was gagged shut, and the power range trip setpoints were reduced to 87% in compliance with Action Statement 3.7.1.1.a.

At the next period of extended shutdown, the valve will be replaced with a spare valve.

As noted, investigation into the problem will continue at that time, and a Supplemental Report will be submitted upon completion.

FAILURE DATA:

Valve 23MS15 manual actuator had failed before on January 14, 1982.

A review of the previous occurrence will be made as part of the investigation into the present problem.

Crosby Valve and Gage Co.

1500 lb. Flanged Inlet Safety Valve Mark F-12 Prepared By R.

Frahm General Manager -

Salem Operations SORC Meeting No.

82-73