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'Public Service Electric and Gas Company P.O.' Box 236 Hancocks Bridge, New Jersey 06038

Salem Generating Station

November 13, 1989

U. S. Nuclear Regulatory CommissionDocument' Control DeskNashington, DC 20555

Dear. Sir:

SALEN CENERATING STATIONLICENSE NO. DPR-7SDOCKET NO. 50-311UNIT NO. 2LICENSEE EVENT REPORT 89-016-00

This Licensee Event Report is being submitted pursuant to therequirements of the Code of Federal Regulations 10CFR50.73 (a) (2) (i) (B) . This report is required within thirty (30) daysof discovery.

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| Sincerely yours,

s.

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L. K. Miller iGeneral Manager - !

Salen Operations

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8911200087 091113PDR ADOCK 05000311 /g iS P5c

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LK:ENSEE EVENT REPORT (LERI sp a n ** **,

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Tech. Spes. Action statesment 3.0.3 Entry - 3 of 4 Main Steas Isol valves Inoperableevent este<si ten manen e me on, are m orwen enciuties owvoivoo .

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On 10/14/89, during a controlled shutdown (for Maintenance), 3 of the 4nain steam isolation valve (MSIVs) failed to close within 5 seconds, *

contrary to the requirements of Technical Specification Surveillance4.7.1.5. Since the Action Statements for Technical Specification 3.7.1.5only apply if no more than one (1) MSIV is inoperable and three (3) of .

the MSIVs were declared inoperable. Technical Specification Action I

Statement 3.0.3 was entered. The root cause of this event has not been e

determined to date. In the past, the hydraulic bypatse valves have beenresponsible for MSIV closure time concerns; therefore, the hydraulicbypass valves for each of the 3 MSIVs which did not close within 5ceconds, were disassembled and inspected. No equipment problems / concernscere identified. Investigation for the root cause of this event iscontinuing. A probabilistic risk assessment associated with theincreased closure time has been initiated. A supplemental report will beissued to document the completion of investigations. The supplemental ,,

report will address the results of the probabilistic risk assessment, any'

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| cdditional cort mive ectiont., required and the root cause of this event.The MSIVs were declared operable upon successfully completing a re-testof the Technical Specification Surveillance at 1715 hours on November 4,1989. The Unit u s returned to Mode 1 (Power Operation) on November 4,1989 at 1910 hours. A License Change Request is being considered tocodify Technical Specification 3.7.1.5 applicability if more than one ofthe MSIVs are kept closed (i.e., in their " safe" position).

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.. LICENSEE EVENT REPORT (LER) TEXT CONTINUATION,

lilem Generating Station DOCKET NUMBER LEP NUMBER PAGE |~

Valt ' 2_ 5000 M 89_-Q1_6_QO 2 of__ 5 |

EkAMT_AND__EYSTEM_IDENTIFIC4TJOjf1 j

Westinghouse - Pressurized Water Reacton

Energy Industry Identification Sys'.en (EIIS) codes are identified inthe text as lxxl .

I*1pKNTIElCATION OF OCCUERENCE:_ j

Technical Specification Action Statement 3.0.3 Entry - Three of the9 Four Main Steam Isolation Valves Declared Inoperable j

Event Date: 10/14/89-

Report Date: 11/13/89 |)

This report was initiated by Incident Report No. 89-628. [

EQNDITIONS PRIOR TO OCCURRENCE 1 [l

Mode 3 (Hot Standby); The Unit was in the process of shutting down in !support of required maintenance.

IDESCRIPTION OF OCCURRENCE:

On October 14, 1989 three (3) of the four (4) main steam isolation ,

valve (MSlVs) ISBl failed to close within the five (5) second period, i

contrary to the requirements of Technical Specification Surveillance '

4.7.1.5. Since the Action Statements for Technical Specification '

3.7.1.5 only apply if no more than one (1) MSIV is inoperable and i

three (3) of the MSIVs were declared inoperable, Technical ;

Specification Action Statement 3.0.3 was entered at 0545 hours thatday. .

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Technical Specification Action Statement 3.0.3 states: !

"When a Limiting Condition for Operation is not met except as ;'provided in the associated ACTION requirements, within one hour

action shall be initiated to place the unit in a MODE in which t

the specification does not apply by placing it, as applicable, -

in: ,

1. At least HOT STANDBY within the next 6 hours, !

2. At least HOT SHUTDOWN within the following 6 hours, and !,

3. At least COID SHUTDOWN within the subsequent 24 hours.Where corrective measures are completed that permit operation (under the ACTION requirements, the ACTION may be taken in '

accordance with the specified time limits as measured from thetins of failure to meet the Limiting condition of Operation. |Exceptions to these requirements are stated in the individual

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specifications."

Technical Specification Surveillance 4.7.1.5, is required to beperformed every 92 days unless the Unit is on line. Normally thissurveillance is performed during startup following a Unit shutdown.

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LICENSEE EVENT REPORT (LER) TEXT CONTINUATION ['

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821em Generating Station DOCKET NUMBER LER NUMBER PAdE !

Unit 2 5000311 89-016-00 3 of 5 I

:p18CRIPTION_OF OCCURRENCE: (contidl ;

To prevent delays during the return to service of Unit 2 from she ~ !'

recently completed maintenance outage, the MSIVs were operationallychecked after entering Mode 3 during the controlled shutdown. Theoperational check was performed in accordance with procedure i

SP(0)4.7.1.5, " Main Steam Isolation Valve Emergency Closure Time '

Response".

Technical Specification 3.7.1.5 is only applicable in Modes 1, 2 and3; therefore, Technical Specification Action Statement 3.0.3 was

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exited upon entering Mode 4 at 1015 hours the dame day. As stated inthe Conditions Prior to Occurrence section, the Unit was in theprocess of being shutdown to Mode 5 (Cold shutdown), to supportmaintenance outage activities.

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APPARENT CAUSE OF OCCURRENCE 1 (

The root cause of this event has not been determined to date.Investigations are continuing. The Corrective Action summary f

identifies the results of the investigation (s) completed as of the i

date of issue of this LER.

ANALYSIS OF_ OCCURRENCE:

The operability of the MSIVs ensures that no more than one Steam '

Generator (S/G) will blowdown in the event of a steam line rupture. :

This restriction is required to minimize the positive reactivity |effects of the Reactor Coolant System cooldown associated with the |blowdown, and to limit the pressure rise within containment in the ;

event the main steam line rupture occurs within containment.

The MSIVs are manufactured by Hopkinsons and are distributed byAtwood & Morrill. The valves are reverse acting double disk gate Ivalves, with two integral pistons and cylinders. They can beoperated in either of two modes, electrohydraulic for normal open andclosure and steam assist for emergency fast closure.

During normal operation the lower cylinder, which is divided into twochambers by a dividing plate that rides on the stem, has equal ;

pressure between the two chambers by an equalizing orifice and draintube. The valve is held open by the tight seating of the dump valves

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that provide a vent path for steam from the upper chamber. |

Each MSIV has two air-operated dump valves. A three-way valvedetermines if either or both dump valves are used. The position of i

each dump valve is controlled by a solenoid valve, located in the airsupply line to each dump valve. The solenoid valves allow air *

pressure to hold the dump valve in the closed position unless an MSIVemergency closure signal is received.

In the emergency mode of operation, the lower cylinder is used to '

position the valve while the upper cylinder acts as a snubber. When

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.. . LICENSEE EVENT REPORT (LER) TEXT CONTINUATION'

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"'531em Generating Station DOCKET NUMBER LER NUMBER PAGE

' Unit 2 5000311 89-016-00 4 of 5

j' MIALYSIS OF OQCURAENCE: (cor}11dl

the dump valves open, steam evacuates from the upper chamber. The[. equalizing orifice and drain tube cannot make up steam to the upper

chamber as fast as it is exhausted and the resulting differentialpressure closes the valve within five (5) seconds.

The MSIV five (5) second closure time is consistent with the origins 1calculations associated with the accident analysis.

As identified previously, three (3) of the four (4) MSIVs would hkve. possibly closed from approximately 6.5 secondo to approximately 7.5

seconds if required to do so in the event of a design base accident.r-

These times exceed the required 5 second closure time as identifiedin the Technical Specifications. Subsequently, this event isreportable in accordance with Code of Federal Regulations 10CFR50.73 (a) (2) (1) (B) .

CORRECTIVE ACTION:'

The hydraulic system for each valve was drained, refilled with freshoil and properly vented.

In the past, the hydraulic bypass valves have been responsible forMSIV closure time concerns; therefore, the hydraulic bypass valvesfor each of the three (3) MSIVs, which did not close within five (5)seconds, were disassembled and inspected. No equipmentproblems / concerns were identified.

The hydraulic header for the 21MS167 valve was disassembled. Variousvalves and o-rings were replaced. These valves had minor oil leakswhich did not affect the overall stroke time of the MSIV.

Each of the MSIV MS169 and MS171 dump valve closure times werechecked in accordance with Surveillance Procedure 4.0.5-V-MS-5. Theslowest valve was 2.26 seconds. The time limit, per the procedure,is ten'(10) seconds. The results of this test indicate that the dumpvalves probably operated properly during the MSIV fast closuretesting during the shutdown.

|Other utilities who have experienced similar MSIV problems are beingcontacted. Also, the MSIV manufacturer and their distributor arebeing contacted.

Investigations as to the root cause of this event are continuing.

A probabilistic risk assessment associated with the increased closuretime has been initiated.

| The MSIVs were declared operable upon successfully completing i' re-test of the Technical Specification Surveillance at 1715 hours on

November 4, 1989. During the surveillance testing, the dump valve )stacks were observed with no significant observations noted. The

| Unit was returned to Mode 1 (Power Operation) on November 4, 1989 at

| 1910 hours.

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,d* LICENSEE EVENT REPORT (LER) TEXT CONTINUATION ;*

8:lem Generating 3tation DOCKET NUMBER LER NUMBER PAGE '

Mpit_2 5000311 89-016-00 5_of 5s

i!' CORRECTIVE ACTION: (cont'd.L__

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A supplemental' report will bt issued to document the completion of i

investigations. The supplemental report will address the results of !

the probabilistic risk assessment, any additional corrective actions !required and the root cause of this event.

A License Change Request is being considered by PSE4G to modify j

Technical Specification 3.7.1.5 applicability if more than one of the |MSIVs are kept closed (i.e., in their " safe" position). ;

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'd 's,General Manager - >

Salem Operations i

MJP:pc

SORC Mtg. 89-110 |

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