ML18038A885

Forwards Response to Request for Addl Info Re GL 89-19

ML18038A885
Person / Time
Site:	Browns Ferry
Issue date:	08/29/1994
From:	Salas P TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-89-19, NUDOCS 9409120325
Download: ML18038A885 (8)

Text

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ACCESSION NBR:9409120325 DOC.DATE: 94/08/29 NOTARIZED: NO DOCKET FACIL:50-259 Browns Ferry Nuclear Power Station, Unit 1, Tennessee 05000259 50-260 Browns Ferry Nuclear Power Station, Unit 2, Tennessee 05000260 50-296 Browns Ferry Nuclear Power Station, Unit 3, Tennessee 05000296 P AUTH. NAME AUTHOR AFFILIATION SALAS,P. Tennessee Valley Authority R RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

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SUBJECT:

Forwards response to request for addi info re GL 89-19.

DISTRIBUTION CODE: ROOID TITLE: OR COPIES RECEIVED:LTR Submittal: General Distribution

$ ENCL J SIZE:

NOTES RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL PD2-4 1 1 PD2-4-PD 1 1 WILLIAMS,J. 2 2 INTERNAL: ACRS 6 6 NRR/DE/EELB 1 ~ 1 NRR/DRCH/HICB 1 1 NRR/DRPW 1 1 NRR/DSSA/SPLB 1 1 NRR/DSSA/SRXB 1 1 NUDOCS-ABSTRACT 1 1 OC/LFDCB 1 0 OGC/HDS3 1 0 1 1 EXTERNAL: NOAC 1 1 NRC PDR 1 1 D

U NOTE TO ALL"RlDS'ECIPIENTS:

PLEASE HELP US TO REDUCE iVASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM PI-37 (EXT. 504-2083 ) TO ELIMINATEYOUR NAME FROM DISTRIBUTIONLISTS FOR DOCUMENTS YOU DON'T NEEDI TOTAL NUMBER OF COPIES REQUIRED: LTTR 21 ENCL 19

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Tennessee Valley Authority, Post Office 8ox 2000. Oecatur, Alabama 36609 August 29, 1994 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 Gentlemen:

In the Matter Of Docket Nos. 50-259 Tennessee Valley Authority 50-260 50-296 BROWNS FERRY NUCLEAR PLANT (BFN) - UNITS 1I 2~ AND 3 REPLY TO NRC REQUEST FOR ADDITIONAL INFORMATION REGARDING GENERIC LETTER (GL) 89-19 By letter dated June 28, 1994, NRC requested TVA to verify that BFN Units 1, 2, and 3 are bounded by the generic evaluation provided in the Boiling Water Reactor Owner's Group (BWROG) response of April 2, 1990. TVA has reviewed plant-specific drawings and high water level trip records.

Based on the results of this review, TVA has verified that BFN Units 1, 2, and 3 are bounded by the generic evaluation provided in the BWROG response of April 2, 1990.

TVA was requested to propose a suitable alternative for ensuring operability of the overfill protection instrumentation, or reconsider its position that Technical Specifications (TS) were not necessary and submit the recommended TS. The purpose of TS is to impose conditions or limitations upon reactor operation to prevent or minimize the possibility of an event that could pose an immediate threat to public health and safety. 'he Staff's Final Policy Statement on Technical Specifications Improvements for Nuclear Power Reactors (July 22, 1993) established a specific set of objective criteria as guidance for determining which regulatory requirements and operating restrictions should be included in the TS. An assessment by General Electric for the BWROG determined that the vessel overfill protection system should be included in the TS in accordance with Criterion 3 if the instrumentation serves to protect any fuel safety limits.

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U.S. Nuclear Regulatory Commission Page 2 August 29, 1994 The specific objective of reactor vessel overfill protection is to enhance the safety of operating plants by minimizing the potential for water ingress into the steamlines, thereby decreasing the potential to damage the main steamlines or the equipment associated with the steamlines. The reactor feedwater overfill protection system is not credited for fuel protection in any design basis accident or abnormal operational transient described in the BFN Updated Final Safety Analysis Report. Therefore, the instrumentation associated with the feedwater trip on high water level should not be added to the TS.

TVA also considers that TS requirements for the vessel overfill protection system are not necessary for the following reasons. First, TVA has procedural requirements to periodically verify functionality of the BFN overfill protection instrumentation and ensure its availability to mitigate feedwater overfeed events during reactor power operation. Second, BFN operating procedures include steps to prevent reactor vessel overfill events and steps to mitigate reactor vessel overfill events should they occur. Third, TVA's review of the maintenance history of the overfill protection instrumentation indicates that the availability of this instrumentation is nearly 1004. Additional information on BFN procedures and overfill protection instrumentation availability is provided in the enclosure.

Accordingly, TVA will not be adding TS requirements for the reactor vessel overfill protection system. Furthermore, TVA considers that BFN has satisfied the requirements of GL 89-19 and, therefore, GL 89-19 should be closed for BFN.

If you have questions, please telephone me at (205) 729-2636.

No new commitments are contained in this letter.

Si ely Pe ro Salas Manager of Site Licensing Enclosure cc: see page 3

4 U.S. Nuclear Regulatory Commission Page 3 August 29, 1994 cc (Enclosure):

Mr. Mark S. Lesser, Section Chief U.S. Nuclear Regulatory Commission Region 101 II Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 NRC Resident Inspector Browns Ferry Nuclear Plant Route 12, Box 637 Athens, Alabama 35611 Mr. J. F. Williams, Project Manager U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852

ENCLOSURE TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT (BFN)

UNITS 1~ 2q AND 3 BFN REPLY TO NRC REQUEST FOR ADDITIONAL INFORMATION REGARDING GENERIC LETTER (GL) 89-19 1 INTRODUCTION This enclosure provides the BFN summary of procedures, calibration frequencies, trip testing, and trip loop maintenance history, concerning the high water level reactor feedpump trip. Also provided is a summary of the alarm response procedures for the condensate booster pump trip due to high water level.

II HIGH WATER LEVEL REACTOR FEEDPUMP TR1P The reactor feedpumps are tripped on high water level with a two-out-of-three logic. The three sensors are 2-LT 53, 2-LT-3-60, and 2-LT-3-206. Both 2-LT-3-53 and 2-LT 206 are connected to the same condensing chamber; 2-LT 60 is connected to a separate condensing chamber.

Each instrument loop is calibrated by a Loop Calibration Instruction (LCI) (LCI-2-L-03-053, LCI-2-L-03-060, and LCI-2-L-3-206). Part of each LCI requires injecting a simulated signal into the transmitter and verifying the trip relay deenergizes. isSince the trip logic is two-out-of-three, a trip signal not generated and a reactor feedpump trip does not occur. Each LCI is performed once per 18 months.

The reactor feedpump trip is tested in Operating Instruction (OI) 2-OI-3, which includes tripping the feed pump from the control room and verifying the high pressure and low pressure stop valves close. The trip test is performed prior to placing a feedpump in service from a cold condition. The LCI tests the instrument loop and the OI verifies a trip signal results in a reactor feedpump trip; however, a complete trip logic test is not performed and is not required. An instrument check is included in Surveillance Instruction (SI) 2-SI-2, which is performed daily for each loop.

The main turbine trip logic is tested in Special Instrument Instruction (SII) SII-2-XX-47-204. Part of this SII requires placing a jumper across the high level switch contacts and verifying the master trip bus energizes. This SII is performed once per 18 months.

TVA has reviewed the maintenance history for each instrument in each high level trip loop for the time period since Unit 2 restart (May 23, 1991). Excluding work orders on leaks and back-filling the reference legs, there have been nine corrective maintenance work orders (WOs). Of the nine WOs, three were generated during preventive maintenance to replace a capacitor or repair power supplies. One work order was written to calibrate the 2-L-3-60 loop when indications suggested the loop was out of calibration. Two work orders were written when indications suggested that 2-LM-3-53A was causing a minor level transient. The remaining three work orders were written on various components in the 2-L-3-206 loop to troubleshoot excessive noise on the level signal. The work orders reviewed did not result in the high level trip function being disabled. This evaluation indicated that the high level trip function and instrument loops have demonstrated a high rate of availability. The instruments evaluated included:

2-LT-3-53 2-PX-3-53A 2-LI-3-53 2-LM-3-53A 2-LS-3-53A 2-LT-3-60 2-PX-3-60 2-LI-3-60 2-LM-3-60 2-LS-3-60 2-LT-3-206 2-PX-3-206 2-LI-3-206 2-LM-3-206 2-LS-3-206 III'ONDENSATE BOOSTER PUMP TRIP DUE TO HZGH WATER LEVEL BFN does not have an automatic condensate booster pump trip on high water level; however, at six inches above normal level the abnormal water level annunciator will alarm. The Alarm Response Procedure (ARP) for abnormal water level directs the operator to verify water level using multiple indications and if the alarm is valid, to refer to the Abnormal Operating Instruction (AOI) 2-AOI-3-1. The AOI directs the operator to stop injection by tripping pumps or closing discharge valves, as appropriate. The AOI also alerts the operator that if reactor pressure is less than 450 psi, Residual Heat Removal, Core Spray, and/or Condensate and Feedwater could be injecting. The AOI cautions that high reactor water level could lead to a steamline break or other malfunction.

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