ML20044A674

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LER 89-028-01:on 891108,determined That Standby Gas Treatment Sys Heater Control Relays Installed W/O Environ Qualification.Caused by Lack of Procedural Guidance.Relays relocated.W/900625 Ltr
ML20044A674
Person / Time
Site: Peach Bottom Constellation icon.png
Issue date: 06/25/1990
From: Fulvio A, Miller D
PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-89-028, LER-89-28, NUDOCS 9007020040
Download: ML20044A674 (4)


Text

iCCH-90-14129' PHILADELPIIIA ELECTRIC COMPANY W[In/ ) PIACil ll0FIUM KlUMIC POWl:R STATION '

R. D.1. Ilox 208 -

M,F Delta, IYnnsylvania 17314

- rsuai wrnmi-tue ros tat or e nctittsc t C17) 4547014 D. B. Millet. Jr.'

vice treent June 25,1990 Docket No. 50-277 Document Control-Desk.

.U; S. Nuclear Regulatory Commission

' Washington, DC 20555

SUBJECT:

Licensee Event Report Peach Bottom Atomic Power Station - Unit 2 This LER concerns the operability of the Standby Gas Treatment System as a result of circuitry containing relays which were not environmentally qualified. This revision supplements the root cause of this event and provides' planned corrective actions.

Reference:

Docket No. 50-277 Report Number: 2-89-028 Revision Number: 01 Event Date: 11/08/89 Report Date: 6/25/90 facility: Peach Bottom Atomic Power Station RD 1 Box 208, Delta, PA 17314

'This LER is being submitted pursuant to the requirements-of 10 CFR 50.73(a)(2)(v).

Sincerely, Vice President cc: J. J. Lyash, USNRC Senior . Resident Inspector

.T. T. Martin, USHRC, Region I 9007020040 900625 i gDR--ADOCK0500{z}7

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l l l On November 8, 1989, following a review of safety related relay applications it was determined that the Standby Gas Treatment System (SBGT) heater control relays were

, not qualified for the analyzed post loss of Coolant Accident (LOCA) radiation environment. At.1335 hours0.0155 days <br />0.371 hours <br />0.00221 weeks <br />5.079675e-4 months <br />, the SBGT was declared inoperable and a Unit 2 plant shutdown was-initiated in accordance with Technical Specifications. By 0100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br />, on November 9 temporary radiation shielding was installed around the relays, the I:~ l SBGT declared operable and Unit 2 restored to full power. The relays were l

l subsequently relocated to an area in which the calculated Post LOCA Radiation Levels l do not exceed their 2.0E5 rad rating. The root cause of this event was a lack of procedural guidance to control the Environmental Qualification aspects of the l modification design process (CIRCA 1980). An assessment of the Peach Bottom EQ l Program-will be performed to ensure that required components have been included. No l previous similar LERs were identified, u.C f orm 366 00D1

nc , . a v s. wuctimuutavony commession LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Am;ovto ous wo. mo-oios tress: arc raciuty waus on pocut wuussa m paan m ten avusen m Piach Bottom Atomic Power Station "*" "E'#nEl' "UsU r

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Requirements for the Report This report is required per 10 CFR 50.73(a)(2)(v) due to a condition which could have prevented fulfillment of the safety function of the Standby Gas Treatment System (Ells:BD) (SBGT).

Unit Status at Time of Event Unit 2 was in the Run Mode at 100 percent power. Unit 3 was in the Refuel Mode.

Description of Event

  • On November 8, 1989, following a review of safety related relay applications, a '

procurement engineer (contract non-licensed) determined that both the "A" and "B" ,

had been omitted from trainSBGTSystemheater(Ells:EHTR)controlrelays(Ells:RLY)ipmentQualification the Environmental Qualification Report. Evaluation by the Equ .

(EQ)Branchdeterminedthattimedelayrelays 62-5944and62-6023-(AgastatmodelETR)

-were not qualified for the analyzed post Loss of Coolant Accident (LOCA)-high 1 radiation environment in the SBGT fan and filter room. The relays are in the heater '

actuation circuit to provide a time delay to allow SBGT system flow to be established. At 1335 hours0.0155 days <br />0.371 hours <br />0.00221 weeks <br />5.079675e-4 months <br />, both trains of the SBGT System were declared inopei Ale and a Unit 2 plant shutdown initiated in accordance with 51chnical Specification 3.7.B.4. At 2105 hours0.0244 days <br />0.585 hours <br />0.00348 weeks <br />8.009525e-4 months <br /> the "B" train SBGT neater relay es provided with temporary  !

shielding-and declared operable and at 2150 hours0.0249 days <br />0.597 hours <br />0.00355 weeks <br />8.18075e-4 months <br /> Unit 2 was restored to full power.

On November 9,.at 0100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> the "A" train SBGT heater relay was provided with temporary shielding and declared operable.

l Cause of the Event The SBGT heater actuation time delay relays were installed in November 1980 as a modificationtotheheatercontrolsystem(Modification 648). At the time of this modification the PBAPS equipment environmental qualification program controls and criteria were under the early stages of development.

In June 1985 the. environmental qualification report for electrical equipment was completed. During implementation of the equipment environmental qualification program in accordance with IE Bulletin 79-018 " Environmental Qualification of Class

-1E Equipment", and 10 CFR50.49, these relays were excluded from the qualification list of equipment important to safety which has the potential to be subject to a i harsh environment.- '

l The root cause of this exclusion has been determined to have been a lack of 1 procedural guidance to control Environmental Qualification aspects of the i modification process.during the time modification 648 was being implemented. At the time this modification was being implemented Philadelphia Electric Company was in the process of developing its response to Bulletin 79-018. To accomplish this, an l Environmental Qualification task force was established by the Nuclear Engineering l Department (NED). The task force was separated from the main body of NED to allow l full dedication to Bulletin 79-018. Because there was no procedural requirement to

.l notify the EQ task force of modifications being installed, the task force was not l made aware of modification 648 and newly installed relays 6P-5944 and 62-6023.

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oli ol 3 oF o l3 f tXT f# more apoco e regurest use scheepnet 44C Form JAE4 W (1h Consequently, an evaluation of the EQ requirements for these relays was not performed ,

thus leading to their exclusion from the list of environmentally qualified electrical i h equipment.

A procedural requirement to perform an Environmental Qualification review as part of the modification det,ign process was implemented approximately one year later (mid 1981).

Analysis of the Event No safety consequences occurred as a result of this event.

The heater control relays used in the SBGT fan and filter room were purchased as nuclear safety related equipment and could withstand the analyzed post LOCA heat and humidity conditions. They were also qualified to withstand an integrated dose of 2.0 E5 rads. However, the worst case analyzed radiation exposure to the relays is j approximately-3.7 E6 rads. i SBGT is comprised of two full flow trains which may be used by either-plant. The SBGT heaters reduce humidity of air entering the filters (EIIS:FLT) to less than 70 percent. This protects the filters from moisture which would reduce their efficiency. Reduced efficiency of the filters due to failure of the heater control relays during a design basis LOCA in either unit could have resulted in offsite doses in excess of that-analyzed.-

Corrective Actions i A Unit 2 plant s'hutdown was initiated until temporary radiation shielding was in place.

-l The relays were relocated on 5/1/90 to an area in which the calculated post LOCA  ;

I radiation levels do not exceed their 2.0E5 rad rating. '

-l Philadelphia-Electric Company will perform an assessment of the Peach Bottom EQ l Program to provide additional assurance that required items are included.

,i Previous Similar Events

io previous similar Licensee Event Reports were identified.

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Requirements for thi Report-This report is required per 10 CFR 50.73(a)(2)(v) due to a condition which-could have prevented fulfillment of the safety function of the Standby Gas Treatment System (Ells:BD) (SBGT).

Unit ~ Status at Time of Event Unit 2 was in the Run Mode at 100 percent power. Unit 3 was in tim Refuel Mode.

Description of Event On November 8, 1989, following a review of safety related relay applications, a- i procurement engineer (contract non-licensed) determined that both the "A" and "B" train SBGT System heater'(EIIS:EHTR) control relays (EIIS:RLY) had been'omitted from the Environmental Qualification Report. Evaluation by the Equipment Qualification

~ ,

(EQ) Branch determined that time delay relays 62-5944 and 62-6023-(Agastat model ETR)'

were not qualified for the analyzed post loss of Coolant Accident (LOCA) high radiation environment in the SBGT fan and filter room. 'The relays are in the heater actuation circuit to provide a time delay to allow SBGT system flow to be established. At 1335 hours0.0155 days <br />0.371 hours <br />0.00221 weeks <br />5.079675e-4 months <br />, both trains of the SBGT System were declared inoperable and.a Unit 2 plant shutdown initiated in accordance with Technical Specification 3.7.B.4. At 2105 hours0.0244 days <br />0.585 hours <br />0.00348 weeks <br />8.009525e-4 months <br /> the "B" train SBGT heater relay was-provided with temporary shielding and declared operable and at 2150 hours0.0249 days <br />0.597 hours <br />0.00355 weeks <br />8.18075e-4 months <br /> Unit 2 was restored to full power.

On November 9, at 0100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> the "A" train SBGT heater relay was provided with temporary shielding and declared operable.

Cause of the Event The'SBGT heater actuation time delay relays were installed-in November 1980 as a modificationtotheheatercontrolsystem(Modification 648). At the time of'this modification the PBAPS equipment environmental qualification program controls and criteria were under the early stages of development.

In June 1985 the environmental qualification report for electrical equipment was completed. During implementation of the equipment environmental cualification program in accordance with IE Bulletin 79-018, " Environmental Qualification of Class 1E Equipment", and 10 CFR50.49, these relays were excluded from the qualification list of. equipment important to safety which has the potential to be subject to a harsh environment.

l The root cause of this exclusion has been determined to have been a lack of procedural guidance to control Environmental Qualification aspects of the

modification process during the time modification 648 was being implementeri. At the time this modification was being implemented, Philadelphia Electric Company was in l the process of developing its response to Bulletin 79-018. To accomplish this, an l-Environmental Qualification task force was established by the Nuclear Engineering ,

l-Department (NED). The task force was separated from the main body of NED to allow l full dedication to Bulletin 79-018. Because there was no procedural requirement to notify the EQ task force of modifications being installed, the task force was not made aware of modification 648 and newly installed relays 62-5944 and 62-6023.

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r NftC Foret 304A U S NUCLEAM E tiULATORY COMM10SION LICENSEE EVENT REPORT (LER) TEXT CONTINUATION amovio ove No aiso-em exmts: swas -

F ACIL TV NAME (1) DOCELT NUMBER (2) LER NUMetM (61 PAGt 131 Piach Bottom Atomic Powe Station "'" '

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.l Consequently, an evaluation of the EQ requirt.ments for these relays was not performed l

.lthusleadingtotheirexclusionfromthelistOfenvironmentallyqw11fiedelectrical~ )

I equipment. j A procedural requirement to perform an Environmental Quelitication review as part of

the modification design process was implemented approximately one year later (mid

'1981).

Analysis of the Event No safety consequences occurred as'a result of this event.

The heater control relays used in the SBGT fan and filter room were purchased as  !

nuclear sa.fety related equipment and-could withstand the analyzed post LOCA heat and humidity conditions. They were also qualified to withstand an integrated dose of'2.0 E5 rads. However, the worst case analyzed radiation exposure to the relays is approximately 3.7 E6 rads. -l SBGT is comprised of two full flow trains which may be uscd by either plant. . The SBGT heaters reduce humidity of air entering the filters (Ells:FLT) to less than 70 percent. This protects the filters from moisture which would reduce their efficiency. Reduced efficiency of the filters due to failure of the heater control  !

relays during a design basis LOCA in either unit could have resulted in offsite doses j in excess of that analyzed.

Corrective Actions A Unit 2 plant shutdown was initiated until temporary radiation shielding was in place. 9 L ,

l The relays were relocated on 5/1/90 to an area in which the calculated post LOCA.

l radiation levels do not exceed their 2.0E5 rad rating, li l '

l Philadelphia Electric Company will perform an assessment of the Peach Bottom EQ l Program.to provide additional assurance that required items are included.'

i:

Previous Similar Events No' previous similar Licensee Event Reports were identified.

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