ML18033B424

Advises That Util Expects to Complete Implementation of Rev 4 to Emergency Procedure Guidelines by Mar 1991.Response to NRC Comments on Draft Emergency Operating Instructions Encl

ML18033B424
Person / Time
Site:	Browns Ferry
Issue date:	07/06/1990
From:	Medford M TENNESSEE VALLEY AUTHORITY
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9007120164
Download: ML18033B424 (13)

Text

ACCELERATED DIRIBUTION DEMONSTTION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)

ACCESSION NBR:9007120164 DOC.DATE: 90/07/06 ,NOTARIZED: NO DOCKET FACIL:50-260 Browns Ferry Nuclear Power Station, Unit 2, Tennessee 05000260 AUTH. NAME AUTHOR AFFILIATION MEDFORD,M.O. Tennessee Valley Authority RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)

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SUBJECT:

Advise that to util expects to complete implementation of Rev 4 emergency procedure guidelines by Mar 1991. I DISTRIBUTION CODE: A003D COPIES'ECEIVED:LTR ENCL L TITLE: OR/Licensing Submittal: Suppl 1 to NUREG 0737(Generic Ltr 82-33)

SIZE: D S

NOTES:1 Copy each to: S.Black,B.WILSON 05000260

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RECIPIENT COPIES RECIPIENT COPIES ID CODE/NAME LTTR ENCL ID CODE/NAME LTTR ENCL KREBS,M. 1 1 PD 7 7 ROSS,T. 1 1 D INTERNAL: HFB11 1 1 OC/LFMB 1 0 D REG FILE 01 1 1 RES/DSIR/EIB 1 1 EXTERNAL LPDR 1 1 NRC PDR 1 1 NSIC 1 1 NOTES: 5 5 R

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NOTE TO ALL "RIDS" RECIPIENTS:

PLEASE HELP US TO REDUCE WAS'ONTACT THE DOCUMENT CONTROL DESK, ROOM Pl-37 (EXT. 20079) TO ELIMINATEYOUR'AME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!

TOTAL NUMBER OF COPIES REQUIRED: LTTR 21 ENCL 20

TENNESSEE VALLEY AUTHORITY CHATTANOOGA. TENNESSEE 37401 6N 38A Lookout Place JUL 06 1990 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 Gentlemen:

In the Matter of ) Docket No. 50-260 Tennessee Valley Authority )

BROWNS FERRY NUCLEAR PLANT (BFN) UNIT 2 IMPLEMENTATION OF REVISION 4 EMERGENCY PROCEDURE GUIDELINES (EPGs)

References:

1. Letter from Manager, Nuclear Licensing and Regulatory Affairs to NRC dated May 31, 1989, "Browns Ferry Nuclear Plant (BFN) Response to NRC Inspection Report No. 50-260/88-200 on Emergency Operating Instructions (EOIs)

2. Letter from D. M. Crutchfield to 0. D. Kingsley, Jr., dated January 18, 1990, "Browns Ferry's Emergency Operating Procedures/Instructions" TVA committed in reference 1 to implement the Revision 4 EPGs at BFN during 1990. NRC suggested in reference 2 that TVA reevaluate that schedule based on the substantial effort required to develop the Writer's Guide and Revision 4 EPGs and the long lead time required to implement the changes.

As a result of a reevaluation"of the Revision 4 Implementation Project, TVA now expects to complete the project by December 31, 1991. This revised date is based on the following factors. First, contractor selection and contract negotiations resulted in a project initiation date of April 1990 which impacts the development, verification, and validation completion dates. TVA expects to complete these activities in March 1991.

Second, because this project includes an extensive change from the text to flowchart format, TVA plans a minimum of three cycles (four and a half months) of operator training prior to implementation of the upgraded EOIs. TVA will begin this training after the 1991 annual requalification examination cycle.

Thus, training on the upgraded EOIs should be completed by the end of October 1991. This schedule will allow the operators to be properly trained and to become thoroughly familiar with the new procedures, ensuring an easier transition. Two additional months are scheduled to resolve comments resulting from training and to make routine enhancements during implementation.

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U.S. Nuclear Regulatory Commission Juc o6 1980 NRC also identified in reference 2 six items involving the current EOIs which required TVA's attention prior to unit 2 restart. TVA has reviewed each of these items and made corrective actions as necessary. The six items and the resolution for each are discussed in enclosure 1. In that same letter, the NRC staff provided comments for TVA to consider when implementing the Revision 4 EPGs. TVA is addressing those comments as part of the Revision 4 Implementation Project. contains a list of commitments made in this letter. If you have any questions, please telephone Patrick P. Carier at BFN, (205) 729-3570.

Very truly yours, TENNESSEE VALLEY AUTHORITY Mark 0. Medford, Vice President Nuclear Technology and Licensing Enclosures cc (Enclosures):

Ms. S. C. Black, Deputy Director Project Directorate II-4 U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 NRC Resident Inspector Browns Ferry Nuclear Plant Route 12, Box 637 Athens, Alabama 35609-2000 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

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ENCLOSURE 1 RESPONSE TO STAFF CONMENTS ON THE DRAFT EMERGENCY OPERATING INSTRUCTIONS (REVISION 3)

ITEN 1 NRC Comment PC/P-6.1 is intended to prevent actuation of the wetwell sprays if the nozzles are submerged. Spray actuation would result in water from the nozzles entering directly into the suppression pool. The EOIs have taken this action when the level instrumentation is at the maximum value. For BFN, this limit is 20 feet while the nozzles are at 26.4 feet. This results in a space of 6.4 feet where the sprays could possibly be effective, but are not actuated due to limitations of instrumentation. Discussion revealed that there may be alternate methods which could be used to determine the water level beyond 20 feet.

In light of the fact that spray actuation is the last remaining action that could save the containment, all possible means should be taken to assure that the sprays are available. TVA should review the alternate procedure to determine level, rather than simply limiting the action due to primary level instrumentation limits.

~Res ense EOI-2 PC/P has been revised to direct actuation of; suppression chamber sprays based on pressure parameters only. Limitations based on level have been removed from the procedure at PC/P-2 and PC/P-, 6. Base documents have been revised to support this change.

ITEM 2 NRC Comment In general, the reason for the action which is normally given in the EPGs in parentheses is the basis for the action. However, the EOIs have also triggered the action due to instrument limitations as indicated in 1.0 above. If the action is based on instrument limits, it should be so stated rather than the rationale provided in the EPGs.

R~es onse The EOIs have been reviewed to ensure that actions taken based on instrument limits reflect that the instrument range limitations are the basis for the action. PC/P-5 was revised based on this review. Actions based on instrument limits were deleted from PC/P-2 and PC/P-6 as described in Item 1 above.

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Enclosure 1 .

Page 2 of 4 ITEM 3 NRC Comment The draft that the staff reviewed has several inconsistent referrals.

For example, suppression pool water level was given in negative inches from normal as well as a measurement in feet from an absolute reference. Also, the wetwell is referred to as the primary containment as well as the wetwell. While we recognize that the EOIs which the staff reviewed were in draft, special note should be taken to eliminate these types of inconsistencies.

~Res onse TVA agrees that inconsistent referrals should be eliminated.

In the first example given, the inconsistency is necessary due to the need to use narrow-range rather than wide-range instrumentation for determining suppression chamber water level. The narrow-range instrument has a different zero reference point with zero being normal level and reads in inches rather than feet.

The EOIs were reviewed to ensure consistency in the use of terms concerning primary containment, drywell, and pressure suppression chamber. No inconsistencies were found in the procedure. The program manual was revised to include definitions for all terms used to signify components of primary containment.

ITEM 4 NRC Comment The actions indicate that there is no manual action to initiate either, the Residual Heat Removal (RHR) or Core Spray (CS) room coolers. This limitation is not normal for a Mark I design. Therefore, this limitation should be verified before this important option is discarded.

~Res onse At BFN, the RHR and CS equipment area coolers are not provided with manual start capability. The cooler fans auto start on a corresponding pump start or increasing temperature (100'F) in the immediate area.

Main Control Room indicators are provided for monitoring pump room temperatures. Annunciators are provided to alert the operator of cooler failure at 150'F.

The RHR and CS equipment area coolers are designed to remove the heat load in the pump rooms. The design heat load is the loss of heat from the piping, pumps, and motors. The coolers are of limited capacity and are not designed as secondary containment general area coolers.

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Enclosure 1 Page 3 of 4

~Res onse (Continued)

The option to place jumpers at the room cooler circuit breakers in the reactor motor operated valve boards was considered. This option was considered to be unfavorable when weighing the capacity of the coolers and the adequacy of existing controls and instrumentation against the necessity to dedicate personnel to this task alone under accident conditions.

ITEM 5 NRC Comment Several actions within the Secondary Containment Section are based on the operator being able to determine whether the pipe rupture is within the primary or secondary system. However, there is no guidance provided to the operator in determining which system is affected. First of all, this is a deviation of the symptom based EOIs. It requires an evaluation by the operator. Secondly, there is no direction given to the operator.

The EOIs should as a minimum provide some guidance relative to how the operator should determine the break location. Otherwise, the operator is left to his judgment as" to how the location is determined'.

R~es onse EOI-3 has been revised to provide guidance to the operator for determining break location.

ITEM 6 NRC Comment In the EOIs, Contingency 2 (C2) (Emergency Reactor Depressurization) is entered if reactor water level cannot be determined. However, in the Boiling Water Reactor Owners Group (BWROG) Revision 3 of the Emergency Operating Procedures, the appropriate action is flooding the reactor pressure vessel (RPV) when reactor water level cannot be determined.

Emergency depressurization may complicate efforts to restore and maintain RPV water level. TVA has committed to revise this procedure to reflect the BWROG guidance.

R~es onse In the BFN EOIs, C2 is entered if reactor water level cannot be determined. After depressurization, C4 (Reactor Flooding) is entered.

Revision 3 of the BWROG Emergency Procedure Guidelines (EPGs) directs flooding the RPV when reactor water level cannot'be determined.

However, both Revision 3 and 4 of the EPGs require emergency depressurization as a condition for reactor flooding and both call for reactor flooding if RPV water level cannot be determined. Flooding at pressure may threaten primary containment integrity via the main steam

Enclosure 1 Page 4 of 4

~Res onse (Continued) relief valve tailpipes and therefore is only done at low pressures.

Additionally, BFN has only low pressure CS capability which requires depressurization as a prerequisite for flooding. The current procedure steps in the BFN EOIs accomplish the required actions and present no technical inadequacies when compared with the EPGs.

Resolution of this issue involves major changes to the EOIs and will require considerable training. BFN is committed to making no major changes to the EOIs which would require extensive retraining prior to Unit 2 restart. This difference from the BWROG EPGs.will be corrected with the implementation of revision 4 EPGs.

ENCLOSURE 2 LIST OF COMMITMENTS

1. TVA will implement the revision 4 Boiling Water Reactor Owner's Group Emergency Procedure Guidelines (EPGs) at BFN by December 31, 1991.

2. TVA will review and revise as necessary the flowpath in the Emergency Operating Instructions from RC/P (Pressure Control) to C4 (Reactor Flooding) and from RC/L (Level Control) to C4 in the project to implement the revision 4 EPGs. (Item 6)