ML20091K662
| ML20091K662 | |
| Person / Time | |
|---|---|
| Site: | Hope Creek  |
| Issue date: | 01/14/1992 |
| From: | Labruna S Public Service Enterprise Group |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NLR-N92001, NUDOCS 9201270016 | |
| Download: ML20091K662 (8) | |
Text
o Puboc service Electric and Gas Company Stanley LaBruna Pubhc Service Dectric and Gas Company P O. Box 236, Hancocks Bodge, NJ 08038 609 339-1200 v ce r>ietera. wow oreens JAN 1 4 1992 NLR-N92001 U.S. Nuclear Regulatory Commission
-Document Control Desk Washington, DC 20555 Gentlemen:
IN-SERVICE TESTING REQUIREMENTS RELIEF REQUEST REVISION HOPE CREEK GENERATING STATION DOCKET'NO. 50-354 By Letter NLR-N91191 dated November 15, 1991, Public Service Electric and Gas Company (PSE&G) submitted a relief request for the In-Service Testing (IST) requirements pertaining to the Post Accident Sampling System (PASS) containment isolation valves.
PSE&G is hereby submitting'a revision to that relief request.
The. November 15, 1991 submittal proposed, as alternate testing, that the affected valves would be tested every 18 months.
Based upon telephone: conversations with Mr. Steve Dembek, USNRC Licensing Project Manager for Hope Creek, PSE&G is revising this request to propose that the required testing be conducted during cold shutdowns.
This is the only-change to the relief request.
The revised relief request is contained, in its entirety, in.
i
'Should you have any questions, we will be pleased to discuss them with you.
Sincerely,
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1 9201270016 920114 PDR-ADOCK 05000354 P
Document Control Desk 2
MN I 4 1992 NLR-N92001 A*,tachment C
Mr.
S.
Dembek USNRC Project Manager - Hope Creek Mr. T. T. Martin, Administrator
'USNRC Region I Mr.
K. Tosch, Chief Bureau of Nuclear Engineering New Jersey Department of Envirorimental Protection
ATTACllMENT ONE IN-SERVICE TESTING REQUIREMENTS RELIEF REQUEST REVISION 110PE CREEK GENERATING STATION DOCKET No. 50-354 M
NLR-N93001 HOPE CREEK IST COMPONENTSt Port Accident Sampling System (PASS), Remote Manual Containment Isolation Valves RC-SV-8903A and-RC-SV-8903B.
CATEGORY:
These valves are ASME Category A fast acting solenoid valves.
TEST REOUIREMENTS FOR WHICH RELIEP IS REOUESTED:
RC-SV-8903A and RC-SV-8903B are currently exercised tested, stroke time tested and fail safe tested overy three months in accordanca with the following ASME Code requirements:
IWV-3412 Exercisinct Procrdgr_q (a) Valves shall be exercised to the position required to fulfill their function unless such operation is tact practical during plant operation.
If only limited operation is practical during plant operation, the valve shall be part-stroke exercised during plant operation and full-stroke tested-dur'ng cold shutdowns.
Valves that cannot be exercised during plant operation shall be specifically identified by the Owner and shall be full-stroke exercised during cold shutdowns.
Full-stroke exercising during cold shutdowns for all valves not full-stroke exercised during plant operation shall be on a frequency determined by the intervals between shutdowns as follows:
For intervals of 3 months or longer - exercise during each shutdown..
For intervals of less than 3 months - full-stroke exercise is not required unless 3 months have passed since last shutdown exercise.
(b)'The'necessary valve disc movement shall be determined by exercising the valve while observing an appropriate indicator, which signals the required change of disk position, or observing indirect evidence (such as changes in system pressure, flow rate, level, or temperature),
which reflect stem or disk position.
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NLR-N92001
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HOPE CREEK IST IWV-3413 Power Opgrated V31ygg (a)-The. limiting value of full-stroke-time of each power
-operated valve shall be specified by the owner.
Full-stroke time is that time interval from ireltiation of the actuating signal to the end of the actuating cycle.
(b) The stroke time of all power operated valves shall be measured to the nearest second, for stroke times 10 seconds or less, or 10% of the specified limiting stroke time for full-stroke times longer than 10, whenever such a valve is full-stroke tested.
IWV-3415 Fail-Sgfe Valves When practical, valves with fail-safe actuators shall be tested by observing the operation of the valves upon loss of actuator-power.
If these valves cannot be tested once every 3 months, they shall be tested during each cold shutdown; in caac of frequent cold shutdowns, these valves need not be tested more often than once every three months.
BASIS POR RELIEF:
Testing RC-SV-8903A and RC-SV-8903B while at power has, on several occasions, caused inadvertent plant transients and/or actuations--of Emergency Safegards Features (ESFs).
This has been attributed to pressure perturbations caused by cycling the affected valves.
These perturbations are communicated, via instrumentation sensing lines, to various reactor level transmitters.
The most recent event occurred on September 23, 1991 and is described here in detail.
Initial conditions were as follows (reference Hope Creek P&ID Non. M-38, sheets 1 and 2 and M-42, sheets 1 and 2):
Reactor at 100% power Reactor Level at 35" Reactor Water Levcl Control selected to "A" Channel Line downstream of-RC-SV-8903B depressurized due to cycling the jet pump sample valve, RC-SV-0624-D24, during puriodic qualification testing by Chemistry.
t Line between RC-SV-8903A and B at some indeterminate low pressure due to minor leakage past RC-SV-8903B.
Operations initiated PASS Containment Isolation Valve Inservice testing in accordance with OP-IS.RC-0101(Q).
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ATTACHMENT 1
4 NLR-N92001 HOPE CRFEK IST l
Upon opening the upstream PASS jet pump sample containment isolation valve, RC-SV-8903A, a pressure perturbation was initiated due to the lower downstream pressure which caused RC-SV-8903B, the downstream valve, to lift to its full open position.
This was indicated by the proceus computer alarm chronology.
The pressure reduction was subsequently felt at the variable leg side of 1BBLT-N085A, the reactor shroud level (fuel zone range) transmitter.
This is a Rosemount 1153 transmitter utilizing an oil-filled capacitor as its sensor.
Insofar as the transmitter sensor assembly _ constitutes a filled system of small volume, any pressure perturbation can readily propagate through it to the reference side of the transmitter; at this point, it le in direct communication with all the instruments on the Channel "A"
reference leg.
The volume of this portion of the system is relatively small since Hope Creek utilizes 3/8" stainless steel tubing from the excess flow check valves outside containment all the way to the instruments.
The somewhat dampened pressure perturbation at the reference leg side of 1BBLT-N085A is therefore propagated to all Channel "A" reactor water level and
- steam dome pressure transmitters.
The reactor water level transmitters sense the differential pressure between a constant height of water (reference leg) and the height of water in the reactor (variable leg), both of which are exposed to reactor pressure.
The differential pressure is therefore proportional to reactor water level.
Since a small change in differential pressure translates into a relatively large change in level, a pressure perturbation can cause these transmitters to momentarily sense a change in level beyond their setpoints while actual level remains constant.
On this occasion, the change in level as sensed by the affected transmitters wac on the order of 40" of water; this was indicated by the GETARS computer.
On other occasions involving attempts to sample from the PASS jet pump sample line, or valving transmitters, even larger transients have been noted.
The reactor pressure instruments are not as susceptible to pressure perturbations since they require larger pressure changes to reach their setpoints, i
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i NLR-N92001 l
HOPE CREEK IST The. instruments of primary concern including their corresponding setpoints and trip functions are as follows:
1SHLT-N081A NSSSS (Level 1 and 2)
IBBLT-N091A HPCI, Core Spray, RHR (Levels 1, 2 and 8)
IBBLT-N091E HPCI, Core Spray, RHR (Levels 1, 2 and 8) 1 SALT-N402A Redundant Reactivity Control System (Levet 2)
IBBPDT-N004A Reactor Water Level Control IBBUT-NOBOA RPS, NSSSS (Level 3)
On this occasion, GETARS indicated water level oscillated due to the pressure pertarbation four times in a period of approximately 250 milliseconds.
The lowest level' indicated by GETARS was approximately -2.5".
Since this is below the calibrated range of the instrument (0-60 inches) it is taken as an approximation as linearity cannot be confirmed outside the calibrated range.
As a result of dropping below +12.5",
the following occurred:
1.
A full recirc runback and reactor water level setpoint setdown to +18" was generated from the Reactor Water Level Control System'(1BBPDT-N004A).
This was a result of Reactor Water Level Control using the Channel "A'
transmitter for control.- The channel selected for control supplies the
-signal to the alarm units which generate the runback and setpoint setdown signals.
2.
A. half scram on RPS Channel "A" was generated (1BBLT-N080A).
3.
A half isolation signal was generated by.NSSSS (1BBLT-N080A) for the RHR' Shutdown cooling inboard isolation valve 1BCHV-F009-E11,_ reactor head' spray inboard isolation valve 1BCHV-F022-E11, RHR flush to radwaste inboard isolation-Valve 1BCHV-F049-E11, RHR inboard sample valves 1BCSV-F079A and B.
As a result of the. full runback, actual reactor water level started to increase.
The water level increase coupled with the reduced water level setpoint caused all three reactor feedpump turbine low pressure control valves to fully close.
This in turn transferred the turbines to Governor Hanual Control.
Prompt operator action was necessary to control reactor water level and prevent further degradation of plant conditions.
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'"6-LThere have been two other occasions-in which operation of the.
PASS-jet' pump 1 sample valves have directly.or indirectly resulted 2in-ESF;actuations.:
On August-22, 1986, during'powerfascension testing, PASS was
.being utilized to obtain reactor-coolantTsamples.. Pressure perturbations induced by valving-manipulations caused 1BBLT-H091A and E-to sense level both below ~38" and above +55".
Consequently,. the HPCI system received-both an' initiation signal
=and: turbine' trip signal.1 operator _ actions were required to-
' restore:the.HPCI system-to standby operation.
Subsequent toLthe August'22, 1986 event, it was decided that
..BB-LT-NO8SA would be isolated prior to testing the. PASS-isolation valves..This was done.on July 14, 1987.
However, when valving the transmitter-back in to service after the test, pressure
- perturbations were once-again experienced =and resulted in HPCI l
Lagain receiving =concurrentcinitiation and turbine trip signals.
M EBNATE TESTING 1-(PSE&G preposes to exercise test, stroke time test, and fail' safe-test RC-SV-8903A and--RC-SV-8903B during cold-shutdowns in accordance-with'the provisions of Subarticles IWV-3412, IWV-3415,-
sand!IWV-3522 and PSE&G Generic Valve Relief Request No.11.
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