JAFP-91-0245, Requests Waiver of Compliance for APRM Instrument Functional Test Frequency,Contained in Tech Spec Table 4.1-1.If Waiver Not Granted,Plant Will Need to Shut Down Unnecessarily.Proposed Waiver Encl
| ML20073D016 | |
| Person / Time | |
|---|---|
| Site: | FitzPatrick  |
| Issue date: | 04/23/1991 |
| From: | Fernandez W POWER AUTHORITY OF THE STATE OF NEW YORK (NEW YORK |
| To: | Martin T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| JAFP-91-0245, JAFP-91-245, NUDOCS 9104260119 | |
| Download: ML20073D016 (8) | |
Text
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James A. FitzPatrick Nucteer Fower Plant P o. Dox 41 Lycoming, Nevi York 13093
-315 342 3840 Y
William Femandea ll t Ori nesio.nt uanager April 23, 1991 JAFP-91-0245, Revision 1 Mr. Thomas T.
Martin Regional Administrator, Region 1 United States Nuclear-Regulatory Commission 475 Allendale Road King of Prussia, PA 19406
SUBJECT:
James A. FitzPatrick Nuclear Power Plant Docket No. 50-333 Request for Waiver of Compliance Regarding APRM Instrument Punctional Test Frecuency
Dear Sir:
The Authority requests a Waiver of.Complianco for the Average Power Range Monitor (APRM) instrument functional test frequency contained in Table 4.1-1 of the-James A'.
FitzPatrick Technical Specifications.
If this waiver is not granted, then the Authority would have to shutdown the plant-unnecessarily.
As described in Attachment I, this request satisfies the criteria for a regional Waiver of Compliance 1as; described in_a February 22, 1990 letter from T.
E. Murley to,the NRC's regional administrators.
For the reasons detailed in the: attachment,-this situation could not have been foreseen or avoided.
3l This letter requests a Waiver from Compliance-with APRM instrument functional test requirements.
The Technical Specifications. require that certain functional tests be completed.
on a weekly basis.
The tests are due to be completed by 9:30 P.M. today.
These tests cannot be. completed as required-without causing a plant scram.
On April 20th, a routine operability' check revealed that the "A" main steam line monitor was reading high and oscillating.
The monitor was declared inoperable on Saturday, April 20th, and replacement of the detector began.
The. replacement of the detector was determined to not resolve the problem at 3:00 P.M.-
on April 22th.
Troubleshooting will resume this' evening.
nor n9" 9104260119 910423 Iff0 /
PDR ADOCK-05000333 P
/\\r'
TO:
- MR. THOMAS-T. MARTIN April 23, 1991 FROM:
MR. WILLIAM FERNANDEZ JAFP-91-0245 6
SUBJECT:
REQUEST FOR WAIVER OF COMPLIANCIf Revision 1 REGARDING APRM INSTRUMENT FLNOTIONAL Page TEST FREOUENCY v
Because the Main Steam Line Radiation Monitors (MSLRM) provide ~
inputs to the reactor protection system (RPS), the inoperable "A" MSLRM requires the "A" RPS trip system to_be placed in the tripped condition in accordance with Technical Specification Table 3.1-1, Note-1.
With the "A" side half-scram in place, it becomes impractical to perform the'RPS instrument functional tests required by Technical Specification. Table 4.1-1.
The instrument functional tests generate RPS trip signals and corresponding half-scrams which will either be masked by the existing "A" half-scram or will complete the RPS logic, resulting in a reactor scram.
Prompt action is required because the Technical Specification-Table 4.1-1 surveillance interval for the APRM instrument functional test has already expired and the TS 4.0.B.1 +25%
surveillance interval extension allowance will expire this evening (April 22nd) at 9:30 P.M.
Should you have any questions regarding the proposed changes, please contact Mr. R. T. Liseno.
Very truly yours, O&
WILLI FERNANDEZ WF:lar
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Attachment vbSNRCDocumentControl-Desk cc:
USNRC Resident Inspector.
R. Capra, USNRC.
B. McCabe, USNRC
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ATTACHMENT I-PROPOSED WAIVER OF COMPLIANCE REGARDING APRM INSTRUMENT FUNCTIONAL TEST FREQUENCY-PORC, Chairman Date //d3/9/
/
PORC Meeting 9'/ '9d Date f4MW-New York Power Authority James A. FitzPatrick Nuclear Power Plant-Docket No. 50-333' DPR-59 i
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I 1
.New York Power Authority:
James A. FitzPatrick' Nuclear Power Plant Recuest for Waiver of Comoliance 1.
A Discussion of the Requirements for Which a Waiver is Requested The Authority requests a one-time Waiver of Compliance for the Average' Power Range Monitor (APRM) instrument functional test frequency contained in. Technical Specification Table-4.1-1.
high flux, inoperative, 1
and downscale require an instrument functional-test
-l frequency of once/ week.
These_ tests were last performed on 1
April 14th at 3:30 A.M.,
making the next: test due on.
y April 22nd.
The proposed 1 waiver would grant aLone-time extension of this surveillance interval, fallowing the next-test to be performed by Aprils28th, at_3:30 A.M.
The-proposed extension period exceeds the TS.4.0.B.1 i25%
allowable variation of the. surveillance interval by an additional 75% for a total interval-of'14_ days.
}
2.
A Discussion of-Circumstances ~ Surrounding the: Situation, Including the Need for Prompt Action-
' I s
On* Saturday, April 20th, while-the2FitzPatrick plant was,at=
full power operations,Eplant operators discovered that1the.
"A" Main Steam Line Radiation Monitor (MSLRM)-reading:was oscillating between 1700 and 2000_mR/hr..TheLother three monitors were reading normally at afsteady.1600 mR/hr.-
Troubleshooting activities began on.the "A" MSLRM,and-continued through Sunday.
On Saturday AprilL20th,1the?
monitor was declared inoperable.i'On' Sunday _it wastremoved
-from the main steam line tunne10and the detectorewasi replaced.
-At 3:00 P.M. todayfa preliminary. source l check of-the "A" MSLRM indicated:that:the.oscillationlproblemi remained.
Further troubleshootingsis commencing 1this) 1 evening.
Because the MSRMs= provide inputs to the1 Reactor. Protectio'n l
System (RPS), the inoperable-"A"1MSLRM requires-the;"A"TRPSI II triptsystem to_be placed inutheftripped condition ins 3
accordance-with TS TableL3.-1-1,4Notec1.<SThis-places the:
FitzPatrick plant in _a " half-scram"' condition.: JInithis _
1 condition, any other scram signal-Lon'thei"A"LRPS71ogic.is masked--and!any-scram signal on thei"B" RPSElogiciwil19cause.
~
.a reactor scram.
With the "A" side half-scramtin place, ittbecomes-J l impractical toLperform the'RPStinstrumentifunctional~ tests-
[
required by TechnicalLSpecification Tablet-4.1-1. JThe:
instrument functional? tests generate RPS trip! signals and 7
"3
. corresponding-- half-scrams. --'As L discussed jineSection 11above,-
s the'APRMLinstrument functional tests!areEcurrently due.,The;'
RPS "A" logic APRMs cannotlbe-tested;because their half ; 7 scramisignals are masked.byfthe:MSLRMfhalf-scram.
The'RPS I
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New York Power Authority James A.
FitzPatrick Nuclear Power Plant Recuest for Waiver of Comoliance "B"
logic APRM cannot be tested, because to do so would complete the logic for a full scram, resulting in rapid control rod insertion and plant shutdown.
Prompt action is required because the TS Table 4.1-1 surveillance interval for the APRM instrument functional test has alread( expired and the TS 4.0.D.1 +25%
surveillance internal extension allowance will expire this evening (April 22nd) at 9:30 P.M.
If the Waiver of Compliance is not granted by this time, the three APRM functions must be declared inoperable.
In accordance with TS Table 3.1-1, Note 1, the FitzPatrick plant either must be shutdown with all control rods inserted within four hours, or be in the start-up mode with power level reduced to the IRM range (<15% power) within eight hours.
3.
A Discuselon of Compensatory Actions During the period of the proposed extension of the APRM instrument functional tests, there will be no unnecessary co'ntrol rod movements or changes in reactor power level.
In addition, the operation of the APRMs will continue to be checked once per shift.
The APRM instrument functional test ve21fies the operabi?lcy for the following functions when the mode switch is in the run modet o APRM Upscale High Alarm and Rod Block o APRM Upscale Neutron Trip:and RPS Scram o APRM Downscale Alarm and Rod Block o APRM Inoperative Alarm and RPS Scram - due to APRM mode switch out of operate position or less than minimum required inputs.
Each of these alarm and trip functions are clearly indicated to the control room operator by annunciator alarm, computer alarm, and APRM front panel alarm lights.
Setpoints for the
. upscale high, upscale neutron trip, and downscale alarm are consistently found to be accurate during surveillance testing.
No instances were discovered of these setpoints being out of-tolerance since January 1, 1990.
Setpoint for the inoperative trip on minimum. number of LPRM inputs has a-history of minor drift.- To compensate for this, once each shift the input LPRM readings will be printed out from the Page __1_,
New York Power Authority James A. FitzPatrick Nuclear Power Plant Recuest for Waiver of_Comoliance process computer and reviewed to determine that the LPRM inputs are indeed sufficient to constitute an operable APRM channel.
This will provide adequate assurance that this monitoring parameter does not adversely affect the operability of the APRMs.
4.
A Preliminary Evaluation of the Safety Significance and Potential consequences of the Proposed Request The one-time extension of the RPS APRM high flux, inoperative, and downscale surveillance tests does not have a significant affect on plant safety.
The inability to perform these surveillance tests on sche 6ule does not disable the trip functions.
The one-timo extension of the surveillance interval to a total of 14 days will not result in a significant ruduction in the reliability of the trip systems.
In the highly unlikely event of the failure of any of these RPS trip signals during the duration of the waiver, the consequences would be acceptable as discussed below.
APRM High Flux - This trip signal responds to a neutron flux spike which occurs too rapidly for the APRM flow referenced neutron flux function.
Events which produce a neutron spike at power would also involve changes in other plant parameters for which there are independent and redundant scram signals.
For example, high reactor pressure or turbine stop valve Closure.
APRM Inoperative - Once-per-shift operability-checks of the APRMs will assure that the APRMs remain operable.
Should an AFRM become inoperable, indication is available to the control room operators.
APRM Downscale - This function ensures proper overlup of the APRMs and IRMs during the transition from the start-up mode (IRM) to run mode (APRM).
Since there will be no attempt to reduce power to the start-up mode during the waiver period, there is no safety significance to having this function out of service.
The operating history of the APRMs has been briefly. reviewed from January 1, 1990 to present.
During this timeframe one failure occurred that could have been detected by the APRM instrument functional test alone.
01/11/90 F APRM did not generate an inoperative trip at the required minimum number of LPRM inputs.
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6 New York Power Authority James A. FitzPatrick Nuclear Power Plant Recuest for Waiver of Comoliangg The following are the significant other deficiencies associated with APRMs that would not have been detected by the instrument functional test.
03/09/90 C APRM rod block relay began chattaring and required replacement 06/30/90 A APRM generated a spurious upscale trip during a plant start-up 07/10/90 A APRM generated a spurious upscale trip during plant start-up 09/05/90 E APRM modo switch was replaced due to erratic operation in the test mode 09/25/90 F APRM generated an upscale trip due to a spi'(ing LPRM 01/17/91 F APRM declared inoperative due to too few LPRM inputs Thus, the probability of a failure occurring during this extended surveillance period that could only be found from performance of this surveillance is small.
In addition, since the "A" RPS logic is in the tripped condition for the duration of the waivnr, only one out of three "B" side APRMs needs to function to initiate n reactor scram.
5.
A Discussion Which Justifies the Duration of the Request i
The duration of the Waiver of Compliance until 3:30 A.M. on April 28th provides sufficient time to complete the repair of the failed main steam lina radiation monitor, perform all surveillance tests necessary to return the MSLRM to service, and perform the deferred APRM RPS surveillances.
6.
The Basis for the Conclusion that the Request Does Not Involve a Significant Hazards Consideration Operation of the FitzPatrick plant in accordance with the proposed waiver would not involve a significant hazards consideration as stated in 10CFR50.92, since it.would nott 1.
Involve a significant increase in the probability or consequences of an accident previously evaluated The APRM system monitors the reactor and provides scram signals in response to increases in the neutron flux.
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New York Power Authority James A. FitzPatrick Nuclear Power Plant Recuest for Waiver of ComDliance The proposed waiver provide. a one-time extension of the surveillance interval associated with this system.
This increased surveillance interval does not prevent the APRM from performing its intended function.
This system does not initiate any accidents or transients and its function, to detect and initiato a reactor scram, are unaffected.
Therefore the probability or consequences of an accident previously evaluated remain unchanged.
2.
Create the possibility of a new or different hind of accident from any accident previously evaluated The APRM system provides a reactor core monitoring and scram initiation function only.
The proposed waiver does not involve any change to plant hardware to operating procedures.
The one-time extension of an APRM surveillance interval cannet initiate a new or different kind of accident from any accident previously evaluated.
3.
Involve a significant reduction in a margin of safety Although all of the APRM scram functions remain available, increar'ng the APRM RPS surveillance interval reduces the reliability of the RPS.
This slight reduction in reliability is a result of a " lack of knowledge" which accompanies any increase in surveillance interval.
That is, there is a probability that the instrument could fail during the surveillance interval and remain undetected for a slightly longer period of time.
Other surveillances and the compensatory actions discussed above reduce the likelihood that a failed APRM would remain undetected.
This slight reduction in reliability does not result in a significant reduction in a margin of safety._
7.
The Basis-for the conclusion that the Request Does Not Involve Irreversible Enviror. mental Effects The proposed Waiver of compliance does not effect the type or quantity of radioactive or other materials released from the FitzPatrick plant.
No' change is made to the design or operation of the effluent treatment or monitoring systems.
During the period of the proposed Naiver, routine full power operation of the FitzPatrick plant vill continue with no additional' environmental effects.
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