ML18036B085

Responds to NRC Ltr Re Violations Noted in Insp Repts 50-259/92-33,50-260/92-33 & 50-296/92-33.Corrective Actions: Licensee Plans to Conduct Special Training on CAM Sys Function & Modes to Enhance Operator Knowledge of Sys

ML18036B085
Person / Time
Site:	Browns Ferry
Issue date:	12/02/1992
From:	Zeringue O TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9212080066
Download: ML18036B085 (12)

Text

~( ~~LhawXEu DOCUMENI DIS j.MBUTIONSYH.EVE REGULATORY INFORMATION DISTRIBUTION SYSTEM (Rl'DS)

P

SUBJECT:

Responds to NRC ltr re.violations noted in insp repts 50-259/92-33,50-260/92-33

& 50-296/92-33.Corrective actions:

licensee plans to conduct special training on CAM sys function

& modes to enhance operator knowledge of sys.

DISTRIBUTION CODE:

IE01D COPIES RECEIVED:LTR J ENCL +

SIZE:

TITLE: General (50 Dkt)-Insp Rept/Notice of Violation Response NOTES:

CESSION NBR:9212080066 DOC.DATE: 92/12/02 NOTARIZED: NO DOCKET CZL:50-259 Browns Ferry Nuclear Power Station, Unit 1, Tennessee 05000259 50-260 Browns Ferry Nuclear Power Station, Unit 2, Tennessee 05000260

'0-296 Browns Ferry Nuclear Power Station, Unit 3, Tennessee~

05000296 AUTH.NAME AUTHOR AFFILIATION ZERZNGUE,O.J.

Tennessee Valley Authority RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

RECIPIENT ID CODE/NAME HEBDON,F WILLIAMSiJ.

INTERNAL: ACRS AEOD/DEIB AEOD/TTC t

NRR MORISSEAU,D NRR/DLPQ/LPEB10 NRR/DREP/+PB9H NRR/PMAS/ZLRB12 OE DJ G

02 EXTERNAL: EG&G/BRYCEgJ.H.

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1 RECIPIENT ID CODE/NAME ROSSiT.

AEOD AEOD/DSP/TPAB DEDRO NRR/DLPQ/LHFBPT NRR/DOEA/OEAB NRR/PMAS/ILPB NUDOCS-ABSTRACT OGC/HDS3 RGN2 FILE 01 NRC PDR COPIES LTTR ENCL 1

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1 NOTE TO ALL"RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE PASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 504.2065) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED:

LTTR 27 ENCL 27

Tennessee Valley Authority. Post Office Box 2000, Decatur, Alabama 35609 2000 0, J. "Ike" Zeringue Vice President. Browns Ferry Nuclear Plant gag gp 1992 U.S. Nuclear Regulatory Commission ATTN:

Document Control Desk Washington, D.C.

20555 Gentlemen:

In the Matter of Tennessee Valley Authority Docket Nos.

50-259 50-260 50-296 BROWNS FERRY NUCLEAR PLANT (BFN) NRC INSPECTION REPORT 50-259, 50-260, 296/92-33 REPLY TO NOTICE OF VIOLATION (NOV)

This letter provides TVA's reply to the NOV transmitted by letter from B. A. Wilson to M. 0. Medford dated November 2, 1992.

In that letter, NRC cited TVA with two violations:

(1) for failure to take immediate actions following an alarm condition and (2) for failure of a fire watch to remain attentive.

As described in the enclosure to this letter, TVA denies the first violation.

Also, as previously discussed with NRC, TVA's response to Violation B will be transmitted following the receipt of a second example of Violation B in Inspection Report 50-259, 260, 296/92-37.

The enclosure to this letter is TVA's "Reply to the Notice of Violation" (10 CFR 2.201).

If you have any questions regarding this reply, please telephone G.

D. Pierce at (205) 729-7566.

Sincerely, 8/6g 0

J. Zering e

Enclosure cc:

See page 2

pal20800 800025 PDR ADOCK 0 pD 8

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tg U.S. Nuclear Regulatory Commission DEC 0 P, 1992 Enclosure cc (Enclosure):

NRC Resident Inspector Browns Ferry Nuclear Plant Route 12, Box 637

Athens, Alabama 35611 Mr. Thierry M. Ross, Project Manager U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 Mr. B. A. Wilson, Project Chief U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323

EHCLOSURE Tennessee Valley Authority Browns Ferry Huclear Plant (BFH)

Reply to Hotice of Violation (HOV)

Inspection Report Humber

-2 2 0 2

2-RESTATEMEHT OF VIOLATIO A.

"Technical Specification Table 3.2.E, Instrumentation That Monitors Leakage Into Drywell, requires for drywell air sampling under action note three that upon receipt of alarm, immediate action will be taken to confirm the alarm and assess the possibility of increased leakage.

Alarm response procedure, 1-ARP-0-3, requires for annunciator XA-55-30-12, RA-90-256A Drywell Leak Detection Radiation HI, that the operator request chemistry laboratory take and analyze a

drywell atmosphere sample.

Contrary to the above, on September 25, 1992, immediate action was not taken to confirm an alarm at 2:55 a.m.,

on drywell detection radiation monitor detector, 2-RM-90-256.

The sample was requested but not performed.

At 7:10 a.m.,

the monitor was declared inoperable and logged as inoperable because the particulate channel was erroneously in alarm.

Work order 92-61547-00 was initiated to troubleshoot and correct the problem with the particulate channel in alarm.

Later the 4 to 8 a.m. unidentified floor leakage provided indication of increased drywell leakage and Unit 2 was shutdown.

This is a Severity Level IV Violation (Supplement I) applicable to Unit 2 only.

B.

Technical Specification 3.11.G.l.a, requires that with a required fire-rated sealing device inoperable, within one hour establish a

continuous fire watch on at least one side of the sealing device.

Implementing procedure for fire watches, FPP-2, Fire Protection

Program, Attachment L, requires that the fire watch shall be on continuous alert for fire, signs of fire, and/or any act that might result in a fire.

Contrary to the above, on October 2, 1992, a

NRC inspector identified that the fire watch established by Limiting Condition for Operation, 2-92-184.3.11.G, for an inoperable fire wrap, was not on continuous alert and was inattentive in his duties.

This is a Severity Level IV Violation (Supplement I) applicable to Unit 2 only."

BASIS FOR DISPUTI G VIOLATIOHA Technical Specifications (TS) Table 3.2.E, Limiting Condition for Operation, requires that immediate action be taken, following a drywell continuous air monitor (CAN) alarm, to confirm the alarm and assess the possibility of increased leakage in the drywell.

As required by TS, plant personnel took immediate action to confirm the alarm.

As discussed below, the followup actions taken by plant personnel demonstrated an aggressive approach to assess the source of the alarm and to track this situation until resolution.

At 0250 hours0.00289 days <br />0.0694 hours <br />4.133598e-4 weeks <br />9.5125e-5 months <br /> on September 25,

1992, the channel associated with the particulate filter on the drywell CAN alarmed.

The channel on the drywell CAN to monitor for noble gasses was not alarming.

During this event, plant personnel took immediate actions to confirm the alarm and to obtain corroborating evidence of increased leakage in the drywell.

These actions were completed by 0300 hours0.00347 days <br />0.0833 hours <br />4.960317e-4 weeks <br />1.1415e-4 months <br /> and included monitoring drywell pressure and temperature, drywell radiation recorders, a review of the floor drain sump pump actuations, and a request for chemistry personnel to change the particulate filter in the CAN and to take a

drywell atmospheric sample.

The requirement for these actions is provided in Alarm Response Procedure (ARP) 2-ARP-9-3.

As described

above, Operations requested that Chemistry obtain a drywell atmospheric sample.

However, Chemistry personnel were not sure if a drywell atmospheric sample meant a drywell hydrogen/oxygen sample and contacted the control room for clarification of the request.

At this time, Operations personnel recognized that the ARP was not clear with regard to sampling objectives.

A conscious decision was made not to follow the existing procedure and to initiate a procedure revision to better clarify sampling requirements since Operations intended for a noble gas sample to be analyzed.

However, Chemistry noted that counting of-a noble gas sample would not have given conclusive evidence of a leak.

Consequently, Operations decided to continue to monitor the drywell parameters to obtain corroborating evidence.

It should be noted that even if the sample had been analyzed and showed an increase in activity, then the plant's response would still be to monitor the other parameters as described in the ARP to assess the leakage into the drywell and to confirm and assess the source of the alarm.

In addition, in most cases of increasing drywell leakage, moisture would be expected on the drywell particulate filter.

No moisture was found on the particulate filter when it was removed from the CAN at 0300 hours0.00347 days <br />0.0833 hours <br />4.960317e-4 weeks <br />1.1415e-4 months <br />.

At 0530 hours0.00613 days <br />0.147 hours <br />8.763227e-4 weeks <br />2.01665e-4 months <br />, Operations contacted the duty system engineer.

By 0615 hours0.00712 days <br />0.171 hours <br />0.00102 weeks <br />2.340075e-4 months <br /> the responsible system engineer (SE) arrived in the control room to assess the recent operational history of the CAM.

The SE was aware that the CAM was removed from service the previous day for performance of a surveillance test.

The SE also noted the CAM had been intermittently alarming since the CAN was returned to service.

The SE reviewed other drywell parameters to confirm the source of the alarm.

Without any corroborating

evidence, the SE recommended that the CAM be valved out of service to change and count the particulate filter, to verify the rate of change calculation, and to ensure that the CAM's check source had not become dislodged, thereby contributing to the alarming condition.

Since the CAM was required to be removed from service to take these actions, Operations declared the CAM inoperable.

At 0715 hours0.00828 days <br />0.199 hours <br />0.00118 weeks <br />2.720575e-4 months <br />, the drywell sump pump unexpectedly started.

At 0815

hours, based on the results of the drywell sump pump actuation, moisture found on the latest CAM particulate filter, and the results of the filter's analysis, Unit 2 control room personnel informed the Shift Operations Supervisor of an increase in drywell leakage.

At this time, a drywell atmospheric sample was also taken and the analysis of the sample did not show any increase in activity.

NRC discussed additional concerns in the cover letter to the NOV and in the inspection report.

First, NRC stated in reference to the drywell atmospheric sample that "the sample was requested but not taken."

This appears to be the primary concern for which the violation was cited.

TVA does not believe that this indicated that plant personnel violated TSs or that plant personnel did not believe the CAM alarm was legitimate.

Instead, as discussed previously, there was confusion over which sample should be taken and analyzed and the value of such a

sample.

Subsequently, the ARP was revised to indicate the specific samples required to be taken when the drywell CAN alarms.

Also, NRC noted that "the alarm provided early indication of increased drywell leakage but the indication was not believed."

TVA believes the actions discussed previously indicate that plant personnel believed the alarm was a first indication of increased leakage into the drywell but could not confirm the source of the alarm.

Their subsequent actions were intended to obtain corroborating evidence.

Finally, NRC noted that the leak was not discussed in the 0730 hour0.00845 days <br />0.203 hours <br />0.00121 weeks <br />2.77765e-4 months <br /> plan of the day meeting.

At the time of this meeting, the unexpected actuation of the drywell sump pump had just occurred.

However, analysis of the pump actuation and the subsequently requested analysis of the CAM particulate filter was not completed until 0815 hours0.00943 days <br />0.226 hours <br />0.00135 weeks <br />3.101075e-4 months <br />, after the conclusion of the plan of the day meeting.

In summary, TVA concludes that plant personnel took the correct immediate actions following the drywell CAM alarm to confirm the source of the alarm and continued with the correct followup actions to assess for a possible leak.

The assessment was ongoing until final resolution.

Thus, TVA believes full compliance with technical specifications was maintained throughout this event.

The event did, however, point out the need for additional procedural and training improvements.

In particular, the ARP has been revised to ensure that the proper samples are identified and obtained for specific alarm conditions.

Also, as part of an upcoming operator requalification training cycle, TVA plans to conduct special training on CAM system function and modes, including alarm functions, to further enhance operator knowledge of this system.

VIOLATIOH B TVA will respond to Violation B following the receipt of a second example of this violation in Inspection Report 50-259, 260, 296/92-37.

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