ML23157A257

PR-050 - 57FR14514 - Loss of All Alternating Current Power

ML23157A257
Person / Time
Issue date:	04/21/1992
From:	Chilk S NRC/SECY
To:
References
PR-050, 57FR14514
Download: ML23157A257 (1)

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{{#Wiki_filter:DOCUMENT DATE: TITLE: CASE

REFERENCE:

KEYWORD: ADAMS Template: SECY-067 04/21/1992 PR-050 - 57FR14514 - LOSS OF ALL ALTERNATING CURRENT POWER PR-050 57FR14514 RULEMAKING COMMENTS Document Sensitivity: Non-sensitive - SUNSI Review Complete

STATUS OP RULEMAKING PROPOSED RULE: PR-50 OPEN ITEK (Y/N) N RULB NAME: LOSS OP ALL ALTERNATING CURRENT POWER PROPOSED RULB PED REG CITE: 57PR14514 PROPOSED RULB PUBLICATION DATE: 04/21/92 ORIGINAL DATE POR COMMENTS: 07/06/92 NUMBER OP COMMENTS: EXTENSION DATE: I I 29 PINAL RULB PED. REG. CITE: 58FR37884 FINAL RULB PUBLICATION DATE: 07/14/93 NOTES ON PROPOSED RULB WITHDRAWN ON 7/8/93. PILB LOCATED ON Pl. ATU8. RtJ't.E TO FIND THB STAFP CONTACT OR VIEW THE RULEMAKING HISTORY PRESS PAGE DOWN KEY HISTORY OP THE RULE PART APPECTED: PR-50 RULE TITLE: LOSS OP ALL ALTERNATING CURRENT POWER .OPO~;;~ -RULB SECY PAPER: 92-025 FINAL RULE SECY PAPER: CONTACTl: ALECK SERKIZ CONTACT2: PROPOSED RULE DATE PROPOSED RULE SRM DATE: I I SIGNED BY SECRETARY: 04/15/92 PINAL RULE DATE FINAL RULE SRM DATE: I I SIGNED BY SECRETARY: 07/08/93 STAPF CONTACTS ON THE RULE MAIL STOP: NLS 314 PHONE: 492-3942 MAIL STOP: PHONE:

DOCKET NO. PR-50 (57FR14514} In the Matter of LOSS OF ALL ALTERNATI NG CURRENT POWER DATE DATE OF TITLE OR DOCKETED DOCUMENT DESCRIPTION OF DOCUMENT 04/16/92 04/05/92 FEDERAL REGISTER NOTICE - PROPOSED RULE 07/02/92 06/28/92 COMMENT OFT. DUNNING ( 1} 07/02/92 07/01/92 07/02/92 07/02/92 COMMENT OF NUCLEAR MANAGEMENT AND RESOURCES COUNCIL (WILLIAM H. RASIN, V.P.} ( 2} 07/06/92 06/30/92 COMMENT OF GENERAL ELECTRIC COMPANY (G.B. STRAMBACK} ( 3} 07/06/92 07/01/92 COMMENT OF COOPER-ENTERPRISE CLEARINGHOUSE (C.W. HENDRIX) {

4) 07/06/92 07/01/92 COMMENT OF TVA {T.N. CHAN, CHAIRPERSON} {

5} 07/06/92 07/02/92 COMMENT OF GEORGIA POWER COMPANY {C.K. MCCOY, V.P.) {

6) 07/06/92 07/02/92 COMMENT OF SOUTHERN NUCLEAR OPERATING COMPANY

{J.D. WOODARD, V.P.) {

7) 07/06/92 07/05/92 COMMENT OF OHIO CITIZENS FOR RESPONSIBLE ENERGY,INC

{SUSAN L. HIATT, DIRECTOR OCRE} { 8} 07/06/92 07/06/92 COMMENT OF GPU NUCLEAR CORPORATION {J. KNUBEL, DIRECTOR) {

9) 07/07/92 07/02/92 COMMENT OF ENTERGY OPERATIONS, INC.

{JOHN R. MCGAHA, V.P.} {

10) 07/07/92 07/06/92 COMMENT OF NUCLEAR UTILITY BACKFITTING & REFORM GRP

{NICHOLAS S. REYNOLDS} { 11} 07/07/92 07/06/92 COMMENT OF TU ELECTRIC {WILLIAM J. CAHILL, JR., V.P.} { 12} 07/08/92 07/06/92 COMMENT OF GULF STATES UTILITIES COMPANY {W. H. ODELL} { 17}

DOCKET NO. PR-50 {57FR14514) DATE DATE OF TITLE OR DOCKETED DOCUMENT DESCRIPTION OF DOCUMENT 07/09/92 07/02/92 07/09/92 07/06/92 07/10/92 07/06/92 07/10/92 07/06/92 07/ 10/92 07/ 10/92 07/ 10/92 07/09/92 07/ 10/92 07/10/92 COMMENT OF TVA (MARK 0. MEDFORD, V.P.) (

13)

COMMENT OF SOUTH CAROLINA ELECTRIC & GAS COMPANY (JOHN L. SKOLDS, V.P.) (

14)

COMMENT OF FLORIDA POWER & LIGHT COMPANY (R.E. GRAZIO, DIRECTOR) (

15)

COMMENT OF HOUSTON LIGHTING & POWER COMPANY (WILLIAM J. JUMP) (

16)

COMMENT OF YANKEE ATOMIC ELECTRIC COMPANY (JAY K. THAYER, V.P.) (

18)

COMMENT OF PG&E (GREGORY M. RUEGER, SENIOR VP) (

24)

COMMENT OF BOSTON EDISON (R.A. ANDERSON, SENIOR VP) {

25) 07/13/92 07/06/92 COMMENT OF NORTHEAST NUCLEAR ENERGEY, ET AL

{J. F. OPEKA, EXEC. VICE PRESIDENT) {

19) 07/13/92 07/07/92 COMMENT OF NEW JERSEY ENVIR. PROTECTION & ENERGY

{KENT W. TOSCH) (

20) 07/13/92 07/06/92 COMMENT OF DUKE POWER COMPANY

{HAL B TUCKER, SENIOR V.P.) (

21) 07/ 13/92 07/06/92 COMMENT OF TOLEDO EDISON (DONALD C. SHELTON, V.P.) {

22) 07/13/92 07/08/92 COMMENT OF COMMONWEALTH EDISON (MARCIA A. JACKSON) {

23) 07/14/92 07/10/92 07/ 17/92 07/16/92 07/21/92 07/17/92 07/31/92 07/27/92 08/04/92 07/29/92 07/08/93 07/08/93 COMMENT OF WASHINGTON PUBLIC POWER SUPPLY SYSTEM

{G.C. SORENSEN, MANAGER) (

26)

COMMENT OF FPC (P.M. BEARD, JR., SENIOR VP) (

27)

COMMENT OF VIRGINIA POWER (WILLIAM L. STEWART, SENIOR VP) (

28)

LTR FROM J. KNUBEL, GPU NUCLEAR TO SJC RE: REPLACING RESPONSE TO Q #1 OF THEIR LTR DATED 7/6/92 (COMMENT #9) COMMENT OF ARIZONA PUBLIC SERVICE COMPANY {WI LLIAM F. CONWAY, VP) (

29)

NOTICE OF WITHDRAWAL OF PROPOSED RULEMAKING, PUBLISHED ON 7/14/93 AT 58 FR 37884.

0OCl(ET NUMBER pnoPosEo RULE Pa s-e-... __ (!7 FR /'f 5 J LJ NUCLEAR REGULATORY COMMISSION 10 CFR Part 50

• 93 JUL -8 p 3 :47 AGENCY:

ACTION: RIN 3150-AE0G Loss of All Alternating Current Power; Withdrawal of Proposed Rule Nuclear Regulatory Commission. Proposed rule: Withdrawal.

SUMMARY

The Nuclear Regulatory Commission is withdrawing a notice of proposed rulemaking entitled "Loss of Alternating Current Power" that was published in the Federal Register on April 21, 1992. The proposed rule would have required licensees to test and monitor emergency diese l generators against specified criteria. FOR FURTHER INFORMATION CONTACT: W. Minners, Office of Nuclear Regulatory Research, U.S. Nuclear Regulatory Commission, Washington, DC 20555, telephone (301) 492-3900. SUPPLEMENTARY INFORMATION: On April 21, 1992 (57 FR 14514), the Nuclear Regulatory Commission proposed an amendment to 10 CFR 50.63. The proposed rule would have required that the reliability of all emergency diesel generators be monitored by testing at least monthly. The proposed rule specified criteria for reporting emergency diesel genera tor (EOG) performance and 1 l l'1 Jq3 f j qr,1 'itlfl ~ 6~ corrective action to the NRC based on the failure criteria in the proposed text of 10 CFR 50.63 (a) (3). The comment period expired on July 6, 1992, but comments were received as late as August 4, 1992. In all, comments were received from 29 respondents. Twenty-seven repondents composed of Nuclear Management and Resources Council (NUMARC), licensees, Nuclear Utility Backfitting and Reform Grouop (NUBARG) and EDG Owners Groups opposed the proposed rule amendment for a variety of reasons. The Ohio Citizens for Responsible Energy and the State of New Jersey supported issuance of the rule. The NRC staff evaluated comments received and submitted a recommendation to the Commission that the proposed rule amendment be withdrawn (SECY-93-044). In place of the proposed rule, the NRC staff recommended that guidance for monitoring EDG performance against target levels selected for the station blackout coping analyses be incorporated into the Regulatory Guide and the guidance being developed by NUMARC for implementation of the Maintenance Rule (10 CFR 50.65). Since promulgation of the station blackout rule (10 CFR 50.63) in 1988, the industry has made real progress in improving the reliability of EDGs to start and run upon demand, and the current industry-wide average reliability, in excess of 98 percent, is quite satisfactory. In balancing the recognition of these efforts and the high level of actual diesel generator reliability against the clear need to maintain such performance, the commission believes a rule is not needed and therefore withdraws the proposed rule. Nevertheless, the Commission considers it imperative that this action not be misinterpreted as a signal that past efforts and vigilance can now be relaxed or possibly disbanded. Hence, both the staff and industry should continue an aggressive program of maintenance as well as root cause analysis that will continue to of fer assurance that emergency diesel generator rel iability will be maintained at a satisfactory level in the future. The withdrawal of this proposed rule does not preclude the Commission from issuing a similar proposed '{(ule in the future. Dated at Rockville, Maryland, this t -day of J uly 1993. For the Nuclear Regulatory Commission. e Commission.

,nCKET NUMBER n9 -s:~ I. ;i* OSED fiULE fj [r,...._ __ ( 5 1 F fl I '-J St 4) Arizona Public Service Company P 0. BOX 53999

• PHOENIX, ARIZONA 85072-3999 L!OLI\\EiLO USNRC WILLIAM F. CONWAY EXECUTIVE VICE PRESIDENT NUCLEAR
• 92 AUG -4 A10 :22 102-02220-WFC/ JN I _. _ _. *t - R.. 1 J l 29 1992

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q1ANCH Mr. Samuel J. Chilk Secretary of the Commission U.S. Nuclear Regulatory Commission Washington, DC 20555

Subject:

Palo Verde Nuclear Generating Station (PVNGS) Units 1, 2, and 3 Docket Nos. STN 50-528/529/530 Comments on the Proposed Amendment to 10 CFR 50.63, uloss of all Alternating Current Power,* 57 Fed. Reg. 14514, April 21, 1992 File: 92-056-026 Arizona Public Service Company has reviewed the proposed revision to 1 0 CFR 50.63 and the comments submitted to the NRC by the Nuclear Management and Resources Council (NUMARC). We fully endorse the position taken by NUMARC that the rule change is unnecessary for the following reasons: It does not result in an increase in safety; indeed it may decrease safety by the accelerated testing required of the Emergency Diesel Generators, The intended goal of Generic Safety Issue B-56 is being met, The requirements are essentially redundant to the Maintenance Rule, 10 CFR 50.65, Additional enforcement authority is unnecessary. We therefore urge the Commission to abandon promulgation of this proposed amendment. card \\,.,.,.ed..., Ae'fJ'iOW~ UJ

U.S. NUCL:. '., -. :-- _,_:.. :,.,,.-::.,~i,:::~;~ 1i,-'1S3101\\ DOC 1-:,=1.~i-J. S,::..:,*ilC~ ~~:CTION Oi,::*:-;f,:,;:: 1 hi:. :.?::C!-t:T1\\RY C ** f: !:.~ :c,:., ~~*~i:.. _.,()iJ Post:r:arx r *i1 __ _2l_3..1J<j'l-__ Copi0R hv,...,J_ --- / ______ _ Adcfl CJ;:i:-:..., *,,.,. !j~., -j 3-------- Spec:21 D:- 'f ::;nltX...K).SrP1J.R SfZ..cl<-11.

Mr. Samuel J. Chilk Secretary of the Commission U.S. Nuclear Regulatory Commission Comments on Proposed Amendment to 10 CFR 50.63 Page 2 102-02220-WFC/JNI July 29, 1992 If you have any questions, please call Thomas R. Bradish of my staff at (602) 393-5421. WFC/JNl~ni Enclosures cc: J. B. Martin D.H.Coe C. F. Tedford Sincerely, W. H. Rasin (NUMARC) ~~EP 18 \\992 Acknowledged by caftf '""""'"".. "'"'~

t Ol l\\t... i ((} USNi~C Nuclear '92 JUL 31 P 3 :12 GPU Nuclear Corporation One Upper Pond Road Parsippany, New Jersey 07054 201-316-7000 TELEX 1 36-482 Writer's Direct Dial Number July 27, 1992 C300-92-2187 C320-92-2205 The Secretary of the Commission U.S. Nuclear Regulatory Commission Washington, DC 20555 ATTN: Docketing and Service Branch

Subject:

General Public Utilities Nuclear Corporation Comments on the Proposed Revision to 10CFR50.63 "Loss of All Alternating Power" Revision to Response to Question No. 1 Pursuant to my teleconference on July 27, 1992 with Mr. Aleck Serkiz, please replace our initial response to Question #1 with the response below, which provides additional clarification. QUESTION 1:

RESPONSE

Is there a better way to identify EDG degradation than the proposed trigger values, which is practical for use by licensees, and which will improve detection of reliability degradation while minimizing false alarms? A better way to identify EDG degradation is to supplement the EDG's success in command-to-start with the results of other performance-based monitoring elements. These elements could consist of monitoring the chemistry of lubricating oil, the mean effective pressure per cylinder when the engine is at 100% power, the brake specific fuel consumption of the engine at power, the engine's operating exhaust temperature and the engine's vibration history. The above would provide a thorough understanding of the engine's reliability and could also form the basis for establishing appropriate intervals for engine overhaul. Additionally, EDG or individual component degradation may be identified through the use of an Engine Performance Monitoring GPU Nuclear Corporation is a subsidiary of General Public Utilities Corporation

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C300-92-2187 C320-92-2205 Page 2 Program, Infrared Thermography (electrical inspection) and a Vibration Monitoring Program. However, additional review would be required in order to determine the practicality of the alternate methods, as well as their effectiveness and efficiency in detecting reliability degradation while minimizing false alarms. Our other responses and comments remain unchanged. & Regulatory Affairs Director JK/EP: lga

WllllAML. STEWART , ~aac Senior Vice.Presukf¥0CKET NUM... n ~ ',I "l"ED RULE_.!f_!!,._:::~-- ( S 1-F/2.. JL/Sli,olr;_T't.D USHRC

• 92 JUL 21 p 2 :25 July 17, 1992 Innsbrook Technical Omter 5()(X) Dominion Boulevard Glen Allen, Vi,ginia 23060 804-273-3551 VIRGINIA POWER Docketing and Service Branch Secretary of the Commission Serial No.

92-303 U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Gentlemen: NL&P/GDM - RBP R1 COMMENTS ON PROPOSED REVISION TO 10 CFR 50.63 LOSS OF ALL ALTERNATING CURRENT POWER In the April 21, 1992 Federal Register, the NRC issued proposed rulemaking to amend its regulations regarding the reliability of onsite alternating current sources for light-water-cooled nuclear power plants. Due to the commitments made in response to the Station Blackout Rule, the present high reliability of Emergency Diesel Generators (EDGs) industry-wide, the present diesel operating reporting requirements, and the implementation of the maintenance rule, we believe that this proposed rule is not necessary. Also, referring to the proposed rule, we object to the proposed imposition of daily civil penalties for operation after a EDG reliability trigger value has been exceeded and the initiation of accelerated testing. The purpose of the rulemaking should be to enhance EDG reliability by surveillance and corrective maintenance. Reliability below a "trigger value" does not necessarily constitute long term inoperability, therefore, the proposed approach to civil penalties represents a punitive precedent which is inconsistent with the treatment of other safety systems and likely not to further enhance reliability. Existing enforcement options based on present definitions of operability provide an adequate means of regulatory enforcement. Furthermore, the testing procedure outlined in the proposed rule allows only one test per day toward return from accelerated testing. Consequently, if accelerated testing is required, to obtain the seven consecutive successful starts, a unit would need to stay off line for at least a week. If the EDG in question is a shared diesel for two units, it could require each unit to be off line for a week or penalties to be imposed on both units. Establishing operability after the first satisfactory test while still requiring the performance of accelerated testing for added assurance would preclude this concern. We strongly disagree with this facet of the proposed rule.

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Virginia Power endorses the NUMARC comments provided separately to the NRC and, in addition, submits the attached comments for consideration in this rulemaking. Very truly yours, JL1W W. L. Stewart Attachment cc: Mr. Ron Simard Director, Industry Relations and Administration Division Nuclear Management and Resources Council 1776 Eye Street, N. W. Suite 300 Washington, D. C. 20006-2496

ATTACHMENT COMMENTS ON THE PROPOSED REVISION TO 10 CFR 50.63 LOSS OF ALL ALTERNATING CURRENT POWER DIESEL GENERATOR RELIABILITY A. General Comments While we believe that the proposed rule is unnecessary, these comments are offered for consideration and would apply to any proposed regulatory actions regarding EOG reliability.

1. The proposed rulemaking on 1 o CFR 50.63 states that every emergency diesel generator (EOG) on site, excluding the non-safety related S80 diesel generator, must be tested to items 2.2.6 through 2.2.14 testing in Table 1 of the draft Regulatory Guide.

Partial testing with supporting bases and engineering analyses may be completely adequate for this purpose, particularly if already installed EOG monitoring systems and ongoing analysis are applied. The proposed rulemaking should not so rigidly limit the detailed actions necessary to establish EOG reliability. We suggest alternative methodology be accepted and the proposed rulemaking and Regulatory Guide changed to accept alternatives.

2. The NRC recognized the detrimental effects of excessive EOG testing in previous documentation (e.g., Generic Letter 84-15). Excessive testing has not been addressed in the proposed rule, although accelerated testing is mandated in the proposed regulation. We suggest clarification on this issue.

3. The effective date of the proposed rule is to be six months after publication of the final rule in the Federal Register. Since the starting failure history baseline is the last 100 demands immediately prior to the effective date of the rule, certain licensees could be in immediate noncompliance with the rule. The proposed implementation date should permit time for corrective actions prior to placing the system into nonconformance.

e. April 21, 1992, Federal Register Notice Questions The following are responses to the four questions raised in the April 21, 1992 Federal Register Notice:

1. Is there a better way to identify EDG degradation than the proposed trigger values?

Comment: We know of no better way to monitor EDG performance at this time. However, the installation of EDG monitoring systems along with performance trending and analysis could be used to predict and correct EDG degradation before it leads to failure. The proposed trigger values appear to monitor EDG failures and reliability, not EDG performance or degradation.

2. Is there a better method which could utilize industry-wide EDG performance history to provide adequate reliability information for plant specific use?

Comment: Not at this time. However, specific EDG Manufacturer's Owners Groups could utilize industry data for each type of EDG which could be integrated into an industry-wide database applicable to every station.

3. In light of the recent industry performance and the future requirements of the maintenance rule (1 o CFR 50.65), is the proposed rule necessary?

Comment: No. However, implementation of EDG reliability programs in accordance with NUMARC 87-00, "Guidelines and Technical Bases for NUMARC Initiatives Addressing Station Blackout at Light Water Reactors, Appendix D, EDG Reliability Program" should be verified at each utility, followed by the development of industry standards for the implementation of the maintenance rule regarding EDGs.

4. Should this proposed rule also address EDG unavailability?

Comment: No. The industry, including INPO, the EDG manufacturers and vendors, and the Owner's Groups should address EDG unavailability within their EDG reliability programs. First, the definition of EDG unavailability may be significantly and individually affected by unique plant configurations (i.e., shared diesels), estimated out of service times, and interpretations of the definitions. The industry needs unified definitions for EDG unavailability which do not penalize unique design configurations. Second, EDG reliability and unavailability may be directly related such that dual goals may be counterproductive (e.g., inspections and preventive maintenance, which lead to increased unavailability, may lead to improved EDG performance and the higher reliability). By imposing unavailability goals, the industry may be driven in two contrary directions by conflicting goals. We do not consider an unavailability a prudent goal to regulate unless it can be established that it will not be a conflicting goal to reliability.

1 =****: \\*******: Florida Power CORPORATION ooci<ET NUi rnER PR, PROPOSED RULE.:..:::.------- {__ 51 F/l /L/ SIL/) DOCKETED JUL 17 1992 July 16, 1992 NL92-0082 Mr. Samuel J. Chilk Secretary of the Commission U. S. Nuclear Regulatory Commission Washington, O.C. 20555

Subject:

Comments on the Proposed Amendment to 10 CFR § 50. 63 Loss of All Alternating Current Power

References:

A. 57 Federal Register 14514, April 21, 1992 DOCKETING & ERVICE BRANC B. Letter from William H. Rasin (NUMARC) to Samuel J. Chilk (NRC) dated April 29, 1992

Dear Sir:

Florida Power Corporation (FPC) fully endorses the comments of the Nuclear Management and Resources Council (NUMARC) on the proposed revision to the Station Blackout (SBO) Rule, 10 CFR § 50.63 (Reference A). These comments were contained in Reference B. We offer the following additional comments:

• The industry is firmly committed to maintaining high emergency diesel generator reliability. All nuclear utilities have endorsed NUMARC Initiative SA.

This initiative requires the licensees to maintain emergency diesel generator (EDG) reliability at a level meeting or exceeding the level committed to for their implementation of the SBO rule.

• Additional enforcement authority is unnecessary.

NRC enforcement authority already exists through the utilities ' commitments related to implementation of the SBO rule, 10 CFR 50.63, 10 CFR 50.65 and 10 CFR 50, Appendix B. As noted by NUMARC, this enforcement authority has already been exercised.

• The proposed rule will have a significant negative effect on EOG reliability and safety as a result of the accelerated testing requirements.

Industry experience has demonstrated the negative effect of accelerated testing and this experience must be considered.

• The randomness of EOG failures should be considered.

The NUMARC submittal comments on the high probability of false exceedence of trigger values. POST OFFICE BOX 219

• CRYSTAL RIVER, FLORIDA 32623-0219 * (904) 563-2943 A Florida Progress Company

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U. S. Nuclear Regulatory Commission NL92-0082 Page 2 However, the NRC Staff should also consider the similarly high probability of a unit maintaining an unacceptable EOG reliability without exceeding the trigger values. In summary, FPC does not consider a change to the SBO rule necessary. Current EOG performance within the industry exceeds the reliability goals. The industry is dedicated to maintaining EOG reliability and the NRC has adequate enforcement authority. Further, the proposed change is unacceptable s i nee it uses an unreliable index to enforce reliability and imposes corrective action requirements which will degrade EOG performance. This rule change will not serve the intended purpose and is unnecessary. 9 Sincerely, f:-b:':!i Senior Vice President Nuclear Operations PMB/AEF:ff xc: A. Marion

tvt'lliLL' WASHING TON PUBLIC POWER SUPPLY SYSTEM U'::>NRC P.O. Box 968

• 3000 George Washington Way
• Richland, Washington 99352 "92 Jtt 14 P4 :12 July 10, 1992 GO2-92-164 Docket No. 50-397 Mr. Samuel J. Chilk Secretary of the Commission U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Subject:

~'"NP-2 OPERATING LICENSE NPF-21, WASHINGTON PUBLIC POWER SUPPLY SYSTEM COMMENTS ON PROPOSED AMENDMENT TO 10 CFR 50.63 1 "LOSS OF ALL ALTERNATING CURRENT POWER," (57 FR 14514, APRIL 21, 1992) The Washington Public Power Supply System {Supply System), an NRC licensee, has reviewed the subject proposed amendment to the "Loss of All Alternating Current Power" {Station Blackout) rule and offers the following comments for your consideration. In reviewing the proposed amendment, the Suppl y System has participated in the preparation and review of industry comments and supports the industry comments being submitted on behalf of the industry by NUMARC. It is our opini on that the proposed amendment would do nothing to enhance nuclear safety, and in fact has the potential to degrade safety related equipment and result in increased unavailability of the emergency diesel generators. We support the detailed comments being submitted by NUMARC as representing our own views. We appreciate the opportunity of participating in the U.S. Nuclear Regulatory Commission regulatory process through the review and comment on proposed regulations. Very truly yours, /4~sb anager Regulatory Programs {Mail Drop 280) GCS:sn cc: WM Dean, NRC JB Martin, NRC RV NS Reynolds, W&S NUMARC Document Control Desk/NRC DL Williams, BPA (399) NRC Site Inspector (901A)

U.S. NUCLEAR REGULATORY COMMISS!Ot-. DOCKETiN<.; & srnv:cE S[C flON OFflCE or-TdE SECRETARY OF fHE COMMISSION Dcc:;ment s:atistirs Postrnrr:~ Da!';} v I q-:L Ccp*-:: F;,:~1::\\*::: / Add' I Cuf'.;ifS ~~()iCdUC~l1.,,,.:L e..,,...--.,..._...__ Special Oi:;l(ution 121:LJ)j P!J~ $'e, f=/L:I z.,

Roy A. Anderson Senior Vice President - Nuclear Mr. Samuel J. Chilk Secretary ooc~ET NUMBtl1 PR s--e-PROPOSED RULE J9}!. ~ (_51 Ff< I'-/ SIL/) BOSTON EDISON Pilgrim Nuclear Power Station Rocky Hill Road Plymouth, Massachusetts 02360 Lulh.C; Li* USNHC t/.,_r

• 92 JUL 10 P4 :14

,::,rc-,c~ '-'~ StCht !A,,' DOCKL 1 ING t, '.~Lt,VIC! r f~ANCl-i J u ly 10, 1992 BECo 92- 074 U.S. Nuclear Regulatory Commission Washington, DC 20555 Boston Edison Company Comments on Proposed Revision to 10CFR50.63, "Loss of All Alternating Current Power," 57FR14514, dated April 21, 1992

Reference:

NUMARC Letter to Mr. S. J. Chilk, Secretary, USNRC, dated July 2, 1992

Dear Mr. Chilk:

Boston Edison Company (BECo) endorses the nuclear power industry comments and positions offered to the NRC by the referenced Nuclear Management and Resources Council (NUMARC) letter on the proposed revision to the Station Blackout Rule (SBO), 10CFR50.63. These comments have been formulated by NUMARC with BECo and other licensee's participation. The comments are based upon industry practice and experience in implementating the SBO Rule. ~Du.0-~ R. A. Anderson,/&- WGL/clc/5063

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.,~*.:CK.ET NUM13EH p,r:JOPOSED RULE PR 5 D C.51 Ftt t '-IS/'--/ J. Pacific Gas and Electric Company 77 Beale Street ~ regory M. Rueger San Francisco, CA 94106 Senior Vice President and 415/973-4684 General Manager July 9, 1992 PG&E Letter No. DCL-92-157 Mr. Samuel J. Chilk Secretary of the Convnission U.S. Nuclear Regulatory Convnission ATTN: Docketing and Service Branch Washington, D.C. 20555 Re: Docket No. 50-275, Ol-DPR-80 Docket No. 50-323, OL-DPR-82 Diablo Canyon Units 1 and 2 Convnents on the Proposed Amendment to Alternating Current Power"

Dear Mr. Chil k:

Nuclear Power Generation 10 CFR 50.63, "Loss of All In response to your request for convnents on a proposed amendment to 10 CFR 50.63, "loss of All Alternating Current Power," noticed in the Federal Register on April 21, 1992 (57 FR 14514), Pacific Gas and Electric Company provides the enclosed convnents. PG&E endorses the convnents submitted by the Nuclear Management and Resources Council (NUMARC) to the NRC on July 2, 1992, on the proposed amendment to 10 CFR 50.63 and draft Regulatory Guide DG-1021, as they apply generically to the nuclear industry. Enclosed are additional convnents that are more site-specific to the Diablo Canyon Power Plant. Diablo Canyon's Technical Specifications currently contain a requirement to maintain emergency diesel generator (EOG) reliability goals and reporting requirements for not satisfying the requirement. Also, PG&E has reiterated the convnitment to maintain the required EOG reliability requirements in a recent submittal to the NRC on the Station Blackout rule. Therefore, we, like NUMARC, see no need or basis for this proposed regulation. Alternatively, we reconvnend the regulation be revised to include the equivalent results-oriented approach of the Maintenance Rule (10 CFR 50.65). Applying this approach would allow decreased frequency of load testing, when so justified by exceeding reliability goals, thereby increasing the overall availability of the EDGs. Sincerely, ~JL,___ G~ ry M. Rueger 5809S/85K

U.S. Nt *~t '::,::! :::1*suLATcqy COMMlSSIOt-. Li:. ~:

• . :: ?... sc-w:cr: TCTiON C, *. __ l'F THE Sl:Cf,ETARY CF rHE COMM:SSION

PG&E Letter No. DCL-92-157 cc: Ann P. Hodgdon John B. Martin Philip J. Morrill Harry Rood CPUC Diablo Distribution Enclosure 5809S/SSK/ALN/1572 July 9, 1992

PG&E Letter No. DCL-92-157 ENCLOSURE C<>>ttENTS ON THE PROPOSED AMENDMENT TO 10 CFR 50.63 LOSS OF ALL ALTERNATING CURRENT POWER The following comments are provided on the proposed amendment to 10 CFR 50.63 imposing new requirements related to emergency diesel generator testing and monitoring against perforaance-based criteria. NRC Stat8118nt "The proposed amendments would require licensees to test and monitor emergency diesel generators (EOG) against criteria that indicate possible degradation from the EOG target levels selected for determining the specified station blackout duration." (57 FR 14514, Summary) PG&E COlllllent Since the COPING period determined by 10 CFR 50.63 was predicated upon the selection/c011111itnient to an EOG reliability (0.950 at Diablo Canyon), it is our understanding that the requirement to test and monitor the EOG to said reliability was already required within 10 CFR 50.63. Also, the Diablo Canyon Technical Specifications require testing and monitoring the EDGs against such criteria. NRC Statement "However, the SBO rule did not require licensees to monitor and maintain these reliability values." (57 FR 14514, Need for Amendment) PG&E Coaaent We disagree that the Station Blackout (SBO) Rule did not invoke the requirement for monitoring and aintaining the reliability value determined within the SBO Rule. Furthermore, in PG&E Letter OCL-92-084 (Revised Response to Station Blackout), dated April 13, 1992, to the NRC, PG&E has clearly committed to monitoring and maintaining the EDGs to the reliability value of

• 0.950.

The NRC subsequently approved our April 13 submittal on May 29, 1992. PG&E Coanent on Monitoring of ED& Performance For plants such as Diablo Canyon where there are more than two EDGs within a unit, the extension of the three failures to "all EDGs assigned to a nuclear unit" is unjustified and too restrictive. In a unit with two EDGs, three failures in the last 20 demands of either EOG is justified, in that one EOG has had at least 2 failures in 20 demands. 5809S/85K Therefore, this failure rate would be in violation of a reliability of 0.950 (i.e., equal to 1 failure in 20 demands). However, at Oiablo Canyon where functionally there are three EOGs for each unit, three failures occurring, one by each EOG, is 1 failure in 20 demands on each EDG; thereby, the reliability requirement of 0.950 for station blackout would still be maintained. It is reconnended that the statement "for all EOGs assigned to a nuclear unit" be deleted from this regulation. Specifically, the following should be deleted fr011 the proposed change to§ 50.63(a)(3)(i): " *** or at any nuclear unit (i.e. combining the performance data for all emergency diesel generators assigned to a given nuclear unit rather than based on each individual e111ergency diesel generator)." PGlE C011111ent on Frequency of Testing It is noted that the pending Maintenance Rule focuses on performance-based regulation (PBR). One concept of PBR is that of potentially reducing maintenance, if the reliability goals are being met to increase the overall availability of equipment. In applying such a concept here, it would be appropriate to decrease the frequency of EOG testing if the reliability goals are being exceeded. For example: with 1 or less failures in 40 tests, the frequency of testing should be decreased from mnthly to quarterly. In so doing, the PBR concept of reducing maintenance when reliability goals are met to increase overall availability of the component would be carried over to EOG testing. Note that one of the most significant challenges to potentially damaging an EOG is a loss-of-offsite-power event when an EOG is operating in parallel with the grid during monthly load testing. Recognizing that the ultimate goal of reliability is availability, by reducing the frequency of load testing the overall availability of the EDG can thereby be increased. PGlE Ccar.ent on Implementaticn Diablo Canyon Technical Specifications require that PG&E maintain the EOGs at 0.950 or greater reliability. If this reliability goes below 0.950, the frequency of testing must increase. In addition to writing a Special Report for any EOG failure, we must also expand this report if the number of failures exceeds 7 in the last 100. Considering these Technical Specifications, it further justifies that there is no real basis for the proposed regulation. The proposed regulation invokes so-called TARGET reliability points. However, we already have such points clearly defined in our Technical Specifications. Although the proposed regulation TARGET points are less severe than those in the Technical Specifications, the proposed new requirements still have the appearance of unnecessary regulation. It is also unclear if these TARGET points are to be invoked within the Technical Specifications. 5809S/SSK e Secretary Commonwealth Edison 1400 Opus Place Downers Grove, Illinois 60515 U.S. Nuclear Regulatory Commission Washington, D.C. 20555 DOCKET NUMBER PR S' PROPOSED RULE (S 7 f fl I LJ S l'l) July 8, 1992

• 92 DOC/ Erm USNHC JUL 13 p 4 :QJ Attention: Docketing and Service Branch Commonwealth Edison would like to take this opportunity to comment on the proposed amendment to 1 O CFR Part 50 Section-63 regarding the loss of all alternating current (ac) for light water cooled nuclear power plants (57 Federal Register 14514, April 21, 1992).

Our comments are contained in two enclosures; Enclosure 1 contains responses to the four questions posed in the Federal Register; Enclosure 2 provides specific comments on the proposed rule and to the draft Regulatory Guide DG 1021. Respectfully, Nucle si Geneiri ZNLD/1942/1

L.: .. :.!_t!_t.TOR'/ COMMISSIO~ ...- *; f::::r-W,C~ SECTION .. *~:~ *r, E SECRETARY ';- Tti.: C0/1.;1-l.!SSIOiJ Question 1 Is there a better way to identify EOG degradation than the proposed trigger values, which is practical for use by Licensees, and which will improve detection of reliability degradation while minimizing false alarms? CECo believes that the trigger values identified in NUMARC 87-00 provides the most practical means to identify EOG degradation. Question 2 Is there a method which could utilize industry wide EOG performance experience to monitor EOG reliability, while providing adequate reliability degradation information for plant specific use? CECo believes that tracking to NUMARC 87-00 for Utility conformance is the best method to monitor EOG reliability. Question 3 In light of current industry EOG performance, other applicable NRG regulations and the future requirements of the maintenance rule (10 CFR 50.65), is this proposed rule needed to provide continued confidence in the reliabifity of EOGs and in maintaining the underlying reliability basis used for the Station Blackout rule? CECo believes that the proposed rule is not needed. The issuance of a Regulatory Guide on EOG reliability program requirements would be appropriate for the Industry. Question 4 Should the proposed rule also address unavailability? No, the proposed rule should not address unavailability. CECo believes that availability guidance is not needed in a separate EOG reliability guidance document. High EOG availability does not result in high EOG reliability. The maintenance rule, technical specifications, and the industry wide Plant Performance Indicator Program (PPIP) already addresses EOG unavailability. Therefore, inclusion of unavailability would be duplicative of existing regulations and industry programs. ZNL0/1942/2 EOG Reliability CECo supports the Unit EOG reliability rather than individual EOG performance, based on monitoring failures and successes to start (3 failures within the last 20 demands). The NUMARC 87-00 (revision 1), implemented by the Industry through NUMARC Initiative 5A, is the most practical and effective means of monitoring EOG degradation and reliability. Enforcement Consideration CECo disagrees with the consideration of enforcement actions described in the proposed rule. Other specific plant actions should be addressed before a Severity Level Ill violation for reaching a double trigger exceedance condition is warranted. Enforcement actions based upon a 3/20 trigger for an individual EOG is inappropriate because the sample size of 20 demands is too small to draw conclusions about degrading reliability. Notification to the NRC Operations Center within four hours of the most recent valid failure that places a Unit into a double trigger value, would be difficult. An EOG demand failure must be evaluated to determine whether the failure was valid or invalid. This determination is based upon identifying the cause of the failure, which is not always immediately apparent. A four hour reporting requirement would result in Utilities being forced to consider every failure as valid and then investigating the failure. In many cases, failures are determined to be invalid based upon the approved NRC EOG demand evaluation guidelines. Therefore, a four hour reporting requirement will result in numerous false alert conditions due to the following scenario; a) an EOG failure occurs and if valid results in a double trigger exceedance condition, b) the cause of the failure is not determined within four hours and the demand is classified as valid, c) the subsequent failure investigation leads to evidence, after four hours has elapsed, indicating that the EOG demand failure was invalid. An alternate approach can be to report the double trigger condition within four hours after the most recent EOG demand failure evaluation is completed and the failure is judged to be valid. OrnttRe_gulatoryJ3!tl_d_e___QG.-1021...(_Second PrOJ).Q.s_e~tB~~ion 3 to Reg!.!latQry Guide 1.9) The subheadings in this enclosure those in the draft guide. The definitions utilized in this Regulatory Guide should be based upon the INPO PPIP EOG demand evaluation guidelines (which is currently equivalent to the NUMARC 87-00 guidelines). Referencing the current INPO PPIP guidelines will allow for the most current and accurate EOG demand guidance. INPO continually performs updates to their PPIP guidelines for the industry. ZNL0/1942/3

.. Continued Exceptions Additional guidance should be provided for the acceptance criteria of maintenance and troubleshooting tests. For example, 1) count the demand as a valid demand for operability, if the test is successful, 2) count the demand as an invalid failure if the test fails following maintenance, or 3) count the demand as a valid failure if the test fails due to factors unrelated to the maintenance and the failure does not meet one of the valid failure exceptions. EOG Monitoring Performance a The 3/20 trigger should be based on Unit EOG reliability only and not for w individual EOG performance. The NUMARC 87-00 single trigger values should be utilized to provide an early warning of EOG reliability reduction. The regulatory guide should address EOG reliability not EOG availability. Notification pursuant to Section 50.63 (a) (3) (i) (A) & (8) is not provided in the proposed rule. Increased EOG testing should only be performed on problem EOGs as described in Regulatory Position 2.3.3. The use of increased EOG testing as a result of a double trigger exceedance will cause reduced long term EOG reliability for two reasons. 1) A double trigger increased testing requirement will result in additional EOG demands, which has been proven to cause additional EOG wear and tear and ultimately, reduced reliability. 2) A double trigger increased testing requirement will lead to increased testing of reliable individual EDGs, because a Unit's EOG reliability performance can be reduced to a double trigger condition due to one problem EOG. Recovery from a Double Trigger Recovery from a double trigger should be based upon the following NUMARC 87-00 guidance. "The Unit would not revert to a no exceedence status until an exceedence no longer exists in the applicable number of demands, or two years from the last failure while in an exceedence, whichever occurs first. However, before a Unit could revert to a no exceedence status on the basis of elapsed time, committed improvement actions shall be completed." Reporting Criteria Clarify whether EOG failure reporting is required for all EOG failures or is it required for EOG failures when the criteria established within 50.63(a) (3) (i) is met. When will the rule become effective? Will Technical Specification change requests to convert from Reg. Guide 1.9, Rev. 3 requirements be addressed in an expedited manner? Preoperational and Surveillance Task. Table 1 The test frequencies for tests 2.2.6 thru 2.2.13 should be listed under refueling outage. ZNLD/1942/4

tF~ CENTERIOR ~ /EN/ERGY Donald C. SheHon Vice President

• Nuclear Davis-Besse Docket Number 50-346 License Number NPF-3 Serial Number 2064 July 6, 1992 Mr. Samuel J. Chilk ooc: **-1,*jUMt3tH PR 5 0 PROPOSED RULE

(_,; 7 f '((. I '--/ 5 J L/) LJ 1.,;r,.r_] LD U:iNHC "92 JUL 13 P4 :10 Secretary of the Commission Nuclear Regulatory Commission Washington, DC 20555 Attention: Docketing and Service Branch 300 Madison Avenue Toledo, OH 43652-0001 (419) 249-2300

Subject:

Comments on Proposed Revision to 10 CFR 50.63, "Loss of All Alternating Current Power", 57 Federal Register 14514, April 21, 1992

Dear Mr. Chilk:

Toledo Edison (TE), a subsidiary of Centerior Energy, is partial owner of and is responsible for operation of the Davis-Besse Nuclear Power Station. Toledo Edison has been authorized for power operation of the Davis-Besse Nuclear Power Station since April 1977. As a 10 CFR 50 licensee, Toledo Edison has a vested interest in any policies the U.S. NRC may adopt which can affect the management and operation of a commercial nuclear power plant. Toledo Edison has reviewed the comments drafted on behalf of the nuclear power industry by the Nuclear Management and Resources Council (NUMARC) and the Nuclear Utility Backfitting and Reform Group (NUBARG) and endorses their comments. In addition, Toledo Edison provides the following comments:

1.

The proposed rule effectively endorses Regulatory Guide 1.9 (Revision 3) as the only means of ensuring compliance with the rule for design, testing and monitoring performance of diesel generators. The Emergency Diesel Generators (EDGs) at the Davis-Besse Nuclear Power Station are designed and tested in accordance with an earlier revision of Regulatory Guide 1.9 and EDG performance is monitored in accordance with TE's commitment to NUMARC 87-00, "Guidelines and Technical Bases for NUMARC Initiatives Addressing Station Blackout of Light Water Reactors". Over the past several years, TE has maintained high reliability of the EDGs. Therefore, the imposition of any additional requirements beyond TE's current commitments would not be cost or risk beneficial to TE. Operating Companies. Cleveland Electric Illuminating Toledo Edison JUL 16 190, Acknowledged by card......... -...... --~.....

Docket Number 50-346 License Number NPF-3 Serial Number Page 2

2.

Modification to the enforcement policy in 10 CFR Part 2, Appendix C, which would consider exceeding a "double trigger" an example of a Severity Level III violation, is inappropriate. The NRC states that the purpose of considering this change is to "emphasize the importance of having reliable diesel generators". By virtue of the industry's improvement in diesel generator reliability over the past several years, it is evident that the industry also considers this important and the perceived "threat" of a Severity Level III violation is unnecessary. Should you have any questions or require additional information, please contact Mr. Robert Y. Schrauder, Manager - Nuclear Licensing at (419) 249-2366. Sincerely yours, J4-/fic~ cc: A. B. Davis, Regional Administrator, NRC Region III J. B. Hopkins, NRC/NRR Senior Project Manager Y. Levis, DB-1 NRC Senior Resident Inspector USNRC Document Control Desk Utility Radiological Safety Board

L II Duke Power Company P.O. Box 1006 Charlotte, N.C. 28201-1006 DUKE POWER July 6, 1992 Secretary of the Commission L*OCK[i ED U5NHC

• 92 JUL 13 P 4 :08

u. s. Nuclear Regulatory *commission Washington, D. c. 20555 Attention: Docketing and Service Branch

Subject:

Oconee Nuclear Station Docket Numbers 50-269, -270, and -287 McGuire Nuclear Station Docket Numbers 50-369 and -370 Catawba Nuclear Station Docket Numbers 50-413 and -414 I HAL B. TUCKER Senior Vice President Nuclear Generation (704) 382-4S31 Duke Power Company comments on the Proposed Revision to 10 CFR 50.63, "Loss of All Alternating Current Power" The following discussion is in response to the NRC's request for comments on the proposed revision to the subject rule as it applies to emergency diesel generator (EOG) reliability. These comments are offered in consideration of determining a realistic approach to improving EOG reliability.

Background

The proposed rule and accompanying Regulatory Guide 1.9, Revision 3 are results of discussions and negotiations regarding EDG reliability that began with the station blackout (SBO) issue. The SBO issue highlighted that EOG reliability was a large contributor to core melt probability, and the industry committed to improve EOG reliability through Generic Issue B-56. A Nuclear Management and Resources Council (NUMARC) group and an NRC group worked on this issue concurrently, with the goal to develop a reliability plan that could be adopted by both groups. The result was that two plans were developed simultaneously; Appendix D to NUMARC 87-00 describes the industry position on EOG reliability, and draft Regulatory Guide 1.9, Rev. 3, describes the NRC's position. It was the intent of industry that the Regulatory Guide would incorporate by reference the contents of Appendix D of the NUMARC document; however, this was not the case. Much effort went into discussions between NUMARC and the NRC on how reliability could be improved (especially in light of the recent industry figures which place reliability at 98%+). At the heart of the discussions was the issue of accelerated testing, which industry believes and NRC studies (NUREG-4590) confirm is one of the leading causes of EOG unreliability. JUL 1.6 *1992-Acknowledged by card....... ~.........:-...... -.....

u.s. MY.. :,_-.. 1 * :,~:y :. :-o;::v COMM1ss1or-. DOC 1(,--: !.**:'* \\ ::~:;,v:o~ [.;ECTiON Ci -:'.'. u THE s:ct1ETARY c.: *;,L<[ COMMISSION D:cu:r.cnt Stat15tiCS

u. s. Nuclear Regulatory Commission July 6, 1991 Page 2 Specific Comments The issuance of the Regulatory Guide as a rule is not warranted.

Development and use of a reliability program using NUMARC 87-00, Appendix Das guidance and elimination of accelerated testing will improve or maintain current reliability. Significant improvement of EOG reliability beyond the 98%+ level currently being experienced is an unrealistic expectation. We believe that development of reliability programs using the NUMARC document as guidance with the elimination of accelerated testing is a mucp more effective means of improving reliability than the issuance of fines on a daily basis until a specified number of successful starts is reached. Much of the intent of the rule is duplicated by the maintenance rule. In addition, in order to meet certain requirements of the proposed Guide, it is extremely possible that some utilities would have to install a "swing" diesel that may cost anywhere from $20 million to$ 100 million, depending on the site-specific circumstances and license requirements. This clearly exceeds the scope of the current backfit analysis. There is redundancy and overlap with the proposed 3 in 20 failure reporting requirement and the 4 in 25 "problem diesel" requirement. It is recommended that the 3 in 30 be used as an early warning indication only, with no reporting requirement. Twenty demands represents too small a sample size to be statistically meaningful for use as anything but an early warning mechanism. The corrective action for the 4 in 25 "problem diesel", 7 consecutive starts, is acceptable; however the rule should consider giving utilities the flexibility to decrease this number or use simulated testing, depending on the resolution of the root cause of the valid failures. The problem diesel trigger would then be acceptable as proposed. In addition, Duke believes that reporting each diesel failure, as is currently the practice, serves 'no useful purpose. Duke recommends instead that a report be prepared upon reaching the 4 in 25, 5 in so, and 8 in 100 triggers. This meets the intent of providing a reasonable and useful amount of information when it is needed. This is especially true as it relates to the requirement to make a 4-hour notification after a valid failure. Determining if a failure is valid or invalid can be an intricate process, taking on the order of days rather than hours.The statement should be corrected to state that a notification is required 4 hours after the failure is determined to be valid and a double trigger is exceeded. This will prevent many notifications that would otherwise be made in error. The regulatory consequences for exceeding the double trigger are too severe.Imposing a Severity Level III violation and potential fines for each day that a unit exceeds a double trigger will be a signal to promote fast action, not quality

1 t

u. s. Nuclear Regu a ory Commission July 6, 1991 Page 3 action.

This proposed aspect of the regulation should be deleted. As previously noted, accelerated testing of the EDGs has been shown to do more harm than good; the constant testing, in some cases every 3 days for 2 years, has actually added to the overall unreliability of the machines. The proposed Guide requires accelerated testing when a double trigger and problem diesel trigger are exceeded. This is in direct conflict with the purpose of increasing reliability. This form of testing should be deleted. In lieu of this testing, Duke Power recommends the actions specified in NUMARC's 87-00, Appendix Das the appropriate action for recovery when a double trigger is exceeded. The last paragraph of Section 2.1 should be clarified such that the post-maintenance test to declare the EDG operable does c ount if successful. If not s uccessful, the t est would not count and further troubleshooting would be pursued. Equipment unavailability is addressed in the Maintenance Rule and the use of INPO industry-wide Plant Perf ormance I ndicator Program. Therefore, unavailability should not be addressed again in the proposed rule. Reliability and unavailability are competing goals and the NRC should not promote reduction of prudent maintenance activities to increase availability at the expense of reliability. As an example, the proposed rule indicates that the NRC assumed that EDG availability exceeds 99.3% as a part of the resolution to SBO. The proposed rule further assumes that this availability level will be achieved during power operation and during refueling outages. The latter is a drastic change from current practice. The ability to perform maintenance on EDGs, especially during outages, is necessary. High reliability in EDGs is only partially achieved through condition monitoring. On a per nuclear unit basis, an unavailability level of.007 is about 61 hours per year that a nuclear unit's diesels may be out of service. The current industry median of unavailability is about

• 017. Therefore., the

.007 is grossly insufficient and will result in degraded reliability. Table 1 of the Regulatory Guide allows tests 2.2.6 through 2.2.13 to be performed every 10 years. Currently, these tests are performed every refueling outage. This is a positive aspect of the Guide. However, some of these tests should be performed whenever a significant adjustment is made to the

• generator excitation or governor subsystems.

In addition, the Guide should incorporate enhancements to testing allowed by Generic Letter 84-15 that permit slow starting of the engine and eliminate many of the detrimental effects of fast starting. The Guide should also address and permit the use of simulated testing in lieu of actual testing of the engine. This is especially important for certain subsystems such as controls. Furthermore, the Guide should specify the conditions required to restart on the hot start test as well.

\\

u. s. Nuclear Regulatory Commission July 6, 1991 Page 4 Thank you for this opportunity to comment on this proposed rule.

If there are any questions, please call Scott Gewehr at (704) 373-7581. Very truly yours, ~,4~ Hal B. Tucker cc : Mr. T. A. Reed, Project Manager Office of Nuclear Reactor Regulation

u. s. Nuclear Regulatory Commission Mail Stop 14H25, OWFN Washington, D. c.

20555 Mr. L.A. Wiens, Project Manager Office of Nuclear Reactor Regulation

u. s. Nuclear Regulatory Commission Mail Stop 14H25, OWFN Washington, D. c.

20555 Mr. R. E. Martin, Project Manager Office of Nuclear Reactor Regulation U. s. Nuclear Regulatory Commission Mail Stop 14H25, OWFN Washington, D. c. 20555 Mr. s. D. Ebneter, Regional Administrator U.S. Nuclear Regulatory Commission - Region II 101 Marietta Street, NW - Suite 2900 Atlanta, Georgia 30323 Mr. Aleck Serkiz Office of Nuclear Regulatory Research

u. s. Nuclear Regulatory Commission Mail Stop NLS314 Washington, D. c. 20555

Scott A. Weiner Commissioner DOCKET NUMBER PR S 0 (f 1QPOSED RULE ('57 FR 1~:::2" USNRC State of New Jersey Department of Environmental Protection and Energy Division of Environmental Safety, Health and AnalyticaiSliogdUbs 13 Al 1 :35 CN 415 Trenton, NJ 08625--0415 July 7, 1992

• JF~ ICi... OF Si:.C1ff IA,; V iHJCKi 1 1NG '* '.f.,,;. :Ll'j.

f5RANL'li \\Jerad P. N1cholls,_Ph.D. D,rector The Secretary of the Commission U.S. Nuclear Regulatory Commission Washington, DC 20555

Subject:

Proposed Amendment to 10 CFR 50.63 Loss of All Alternating Current Power The New Jersey Department of Environmental Protection and Energy ' s Bureau of Nuclear Engineering (BNE) has reviewed the subject proposed rule contained in the April 21, 1992 Federal Register. We have the comments delineated below. The BNE concurs that rulemaking is appropriate for establishing requirements for licensees to monitor, maintain, report

failures, and when necessary, establish continued operability for onsite AC power sources.

As stated in the Supplementary Information published with the proposed rule, reliability of onsite diesel generators is a major factor in assuring acceptable safety limits at nuclear plants. This is supported by the relatively high degree of risk contribution diesel generators have in probabilistic risk assessments. The proposed rule would require lic ensees to monitor diesel generator reliability through surveillance tests, and if "failures " occur at a predetermined rate, certain actions are required. However, the term "failure" is not defined in the proposed rule or the existing 10 CFR 50.63. Draft Regulatory Guide, DG-1021 dated April 1992 defines "start failures " and " load-run failures. " The proposed rule does not use these terms nor does it reference this draft regulatory guide. In order to ensure that the intent of this proposed rule is consistently implemented at all facilities and that all appropriate failures are included in the scope of the rule, this key term must be defined within the rule. New Jersey Is an £qua/ Opportunity Employer JUL Recyded Paper 1 6 1992 Acknowledged by card..................................

.:'-'LATORY COMM13S10t-. [X.~,;.: *,,{*};:;. SErw;c*-:=: SECTION on-ICE OF THE SECRET ARY Of 1HE l,OMMISSION Documer.t Statistics Po$tm&rl: Dal~ '7/ f/ 1L Copic3 RtC9i'! d ___ J _ ____ A'Jd'I Copies Reproduced -2~--,,----- Special Di3tr" ution /J,--rl}t f 0 fZr-S:e..r J<l b

Page 2 If you have any questions, please contact Rich Pinney at (609) 987-2086. Sincerely, ~#vi-- Kent w. Tosch, Manager Bureau of Nuclear Engineering c: Jill Lipoti Assistant Director, Radiation Protection Programs N.J. DEPE

UUliY,t I NUMljtH PR PROPOSED RULE !i O - (5 1 FI< l'i 5 I'-!) <If) NORTHEAST UTILITIES General Offices* Selden Street, Berlin, c8~fidJiD ((IlJ THE CONNECTICUT LIGHT ANO POW{A COMPANY WESTERN MASSACHUSETTS ELECTRIC COMPANY HOLYOKE WATER POWER COMPANY NORTHEAST UTILITIES SERVICE COMPANY NORTHEAST NUCLEAR ENERGY COMPANY Mr. Samuel J. Chilk, Secretary Docketing and Service Branch U. S. Nuclear Regulatory Commission Vashington, DC 20555

Dear Mr. Chilk:

Haddam Neck Plant USNHC P.O. BOX 270 HARTFORD, CONNECTICUT 06141-0270 c203) 665-5000

• 92 JUL 13 A11 :16 July 6, 1992 ff I

~ i= ~ [ ( ti 1 \\

• v Docket Nos.

50-213 [;ucit,,., ~ t t v rr 50-245 *. Ni :~ 50-336 50-423 B14183 Re: 10CFR50.63 57FR 14514 Millstone Nuclear Power Station, Unit Nos. 1, 2, and 3 Comments on Proposed Revision to 10CFR50.63, "Loss of All Alternating Current Power," 57 Federal Register 14514, April 21, 1992 Connecticut Yankee Atomic Power Company (CYAPC0) and Northeast Nuclear Energy Company (NNEC0) hereby submit the following commeftit.s in response to the NRC's request for comments on the proposed amendment to 10CFR50.63, "Loss of All Alternating Current Power," 57 Federal Register 14514, dated April 21, 1992. The comments are provided in Attachment No. 1 to this letter for your information and use. In addition to the comments provided in this letter, CYAPC0 and NNEC0 wish to endorse those comments provided by the Nuclear Management and Resources Council. Ve trust you will find our comments useful. Very truly yours, J. /fi;f.-~ Executive Vice President cc: T. T. Martin, Region I Administrator A. B. Vang, NRC Project Manager, Haddam Neck Plant J. T. Shedlosky, Senior Resident Inspector, Haddam Neck Plant J. V. Andersen, Acting NRC Project Manager, Millstone Unit No. 1 G. s. Vissing, NRC Project Manager, Millstone Unit No. 2 V. L. Rooney, NRC Project Manager, Millstone Unit No. 3 V. J. Raymond, Senior Resident Inspector, Mills t one Unit Nos. 1; 2, and 3 0S3422 REV. 4-88 JUL 16 1992 Acknowledged by card.. _ __,_......,

, 1 ., * ;t.:GULX:09Y cm,;:*.1!SS,O,, .. -,.. c::*ri:,1G & srn*.;;cr-: SECTIO~ Off ICE OF THf: SECf1!:TMlY Of THE COMM!SSICf~ Document St8t:stlcs Postmari: Dal:~ ~ ..,/1_7-____ _ Copies R~~iv~d ___ 7 _____ _ Add'I Ccpii:s ReprcdUC'3d =j ____ _ epccial Distnbution t::r.OS. PtJ/2. s:~,r l,:_ I :z_.

Attachment No. 1 Haddam Neck Plant Docket Nos. 50-213 50-245 50-336 50-423 B14183 Millstone Nuclear Power Station, Unit Nos. 1, 2, and 3 Comments on Proposed Revision to 10CFR50.63, "Loss of All Alternating Current Power," 57 Federal Register 14514, April 21, 1992 July 1992

Hr. S. J. Chilk Attachment l/B14183/Page 1 July 6, 1992 Comments on Proposed Revision to 10CFRS0.63, "Loss of All Alternating Current Power," 57 Federal Register 14514, April 21, 1992 General Comment One main objection to certain elements of the station blackout rule, as specified in NUHARC 87-00, is that the emergency diesel generator reliability (EDG) targets account only for failures of the EOG to start, whereas a complete assessment as is typically performed in PRAs account for: o failure to start o failure to run o unavailability due to corrective maintenance o unavailability due to preventive maintenance o unavailability due to testing (where applicable) Typical values for unavailability due to maintenance at Millstone Unit Nos. 1, 2, and 3 and the Haddam Neck Plant lie in the range of 0.01 to 0.02, making maintenance unavailability a major component of the overall EOG unavailability. In this regard, we are in general agreement with the NRC that the previous assumption of unavailability due to test and maintenance of 0.007 is not reflected by actual plant data. Specific Comments The proposed rule provides "Trigger" and "Double Trigger" values of failures and demands which would require further action on the part of the licensee, such as corrective action and reporting. Based on NU's review, the trigger and double trigger values seem reasonable and appropriate. However, NRC' s proposed recovery from a "Double Trigger" condition would be an accelerated surveillance testing frequency, resulting in testing every one to seven days until 7 consecutive failure-free tests have been demonstrated. At some point, the EOGs become overly tested resulting in accelerated wear-out. It is not clear what that point is, but neither is there a technical basis that seven tests in a period of one to seven weeks will improve overall EOG availability. Station Black.out Contribution to Overall Plant Risk Millstone Unit No. 1: Response to the SBO rule has already been credited in the Individual Plant Examinations (IPE). Nevertheless, core melt frequency (CMF) from SBO is approximately two-thirds of the total CHF from internally initiated events, or approximately 9E-6/yr. There are additional contributions from external events such as fire (approximately 10-5/yr). However, improved EOG performance would provide little benefit for fire CMF reduction. Millstone Unit No. 2: Response to the SBO rule has already been credited. CMF due to SBO is below 1 percent of the internal events CHF, and less than lE-6/yr. Millstone Unit No. 3: Response to the SBO rule (installation of air-cooled EOG) has not been implemented nor credited. CHF due to SBO is of the order of SE-

Hr. S. J. Ch ilk Attachment l/B14183/Page 2 July 6, 1992 6/yr, or 10 percent of the internal events CHF. In addition, there is an additional 4E-6/yr from seismic, and 4E-6/yr from fire. The seismic and fire CMF would not be reduced significantly from improved EOG performance, nor from SBO implementation. Haddam Neck: The internal events PRA is currentll under revision. However, the CMF due to SBO is expected to be in the low 10- /yr range for internal events. The contribution from external events including fire and high winds/tornado is of the order of lE-4/yr. However, improvements in EOG performance would not affect the results for external events. Response to Federal Register Questions Is there a better way to identify EOG degradation than the proposed trigger values? As discussed above, the proposed trigger values for EOG reliability seem reasonable. However, the second part of the equation, EDG unavailability due to test and maintenance, is equally important, yet missing. It clearly would not make sense if, in order to meet the trigger values, excessive preventive and corrective maintenance were required, resulting in unavailability of five or six percent. There should be a balance between the two. In essence, a matrix is needed with regard to when corrective action is or is not needed (Figure 1). Is there a better method which could utilize industrywide EDG performance history to provide adequate reliability information for plant specific use? The Nuclear Plant Reliability Data System provides a starting point.

However, if the EOGs at a particular plant are undergoing degradation, it may be because of plant-specific considerations with regard to maintenance and/or environment.

Industrywide information should not be used as a substitute for triggering performance improvements. In light of the recent industry performance and the future requirements of the maintenance rule, is this proposed rule necessary? Probably not, since the EOG will undoubtedly become "risk significant" under the maintenance rule, and have to be monitored in accordance with 10CFRS0.6S(a)(2) or have goals set in accordance with 10CFRS0.6S(a)(l). Should this proposed rule also address EOG unavailability? Notwithstanding the answer to the above question on the need for this proposed rule, EOG unavailability should be addressed either in the proposed rule or under the maintenance rule.

Hr. S. J. Chilk /B14183/Page 3 July 6, 1992 UNAVAILABILITY j increasing RELIABILITY increasing Action Figure 1 Possible EDG Trigger Matrix

PRorosEo*FiuLE. PK £ o (,1F(< li5/Lf) Telephone (508) 779-6711 YANKEE ATOMIC ELECTRIC COMPANY

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..,p* ~ 580 Main Street, Bolton, Massachusetts 01740-1398 YANKEE JAY K. THAYER VICE PRESIDENT and MANAGER OF OPERATIONS July 10. 1992 Secretary of the Commission United States Nuclear Regulatory Commission Washington, DC 20655 Attention: Docketing and Service Branch Dt)Cl{ETING & Ol:rl\\llC:': BRANCH SECY-NAO

Subject:

Comments on the NRC Proposed Rule Concerning the Loss of All Alternating Current Power (57 Fed. Reg. 14514)

Dear Sir:

Yankee Atomic Electric Company (Yankee) appreciates the opportunity to offer comments concerning this proposal to amend the NRC's regulations which deal with the reliability of on-site alternating current sources. Yankee owns the nuclear power plant in Rowe, Massachusetts. Our Nuclear Services Division provides services to other nuclear power plants in the northeast including Vermont Yankee, Maine Yankee, and Seabrook. Yankee is also a member of the Nuclear Management and Resources Council CNUMARC) and the Nuclear Utilities Backfit and Reform Group (NUBARG). We fully endorse the comments concerning the proposed rule which these organizations have filed. The issue of how best to ensure high Emergency Diesel Generator CEDG) reliability has been characterized by at least one Commissioner as an "important opportunity for the Commission to adopt a nonprescriptive results-oriented approach." We suggest that the above-stated goal can most appropriately be accomplished by acknowledging the success of NUMARC Initiative 5A and looking to implementation of the Maintenance Rule and continuing licensee compliance with existing regulations and commitments (e.g., GDC 17, GDC 18, Technical Specifications, etc.) to provide the assurance that the current extremely high industry average EDG reliability is sustained. We see no discernable safety benefit in adding still another layer of regulation particularly when the proposed addition is so poorly justified. It is our belief that rules and the rulemaking process should be as "transparent" as possible. By this we mean that there should be an understandable, objective and coherent basis for a rule including a reasonable justification that the rule will accomplish its stated purpose. The proposed amendment to 10CFR50.63 certainly does not meet this standard. The core of C76\\230 JUL 16 1992 Acknowledged by card.................................,

U.S. ~l:JC'L'.:AR REGULATORY COMMISSIOf'.. L,C'._ ;,,:-;-i1~G & SERVICE SECTION OfrlCE Of THE SECRETARY CF THE COMMISSION Document Statistics Fost1112r!* Date _ __.]"-'/....,1....;;o;...:.l..... 9..;:;2..=---- Co;.,:(:3 ~,:1:. i*,cd ___ / _____ _ Add'I COf,i;.':; 1eproduced ------- Sp0c;a1 Us1nbuuon ilJ;IQ5J /Jl)t! _<; L t- ~.

Secretary of the Commission July 10, 1992 Page 2 the proposal is the concept that there are certain meaningful "trigger values," i.e.* number of failures per a given number of demands. The published justification for the proposed amendment notes:

• The trigger values should not be viewed as a statistical estimate of a target unit EOG reliability, but rather as a threshold at which there is reasonable evidence that EOG reliability has degraded below target levels.* Anyone who has observed discussions of this issue before the Advisory Committee on Reactor Safeguards CACRS) and read the ACRS's May 16, 1992 letter to Chairman Selin recognizes that this statement is, in part, a tacit admission that there is no statistically valid nexus between the proposed triggers and compliance with the EOG reliability targets of the Station Blackout Rule.

The claim that the triggers will provide "reasonable evidence" of degradation of EOG reli ability is not supported by any objective evidence or analysis. In fact, the above-noted ACRS letter makes the very cogent argument that the proposed triggers will "trap 10 percent of the innocents with reliability 0.95 in return for less than an even chance of catching a culprit with reliability degraded to 0.90." A situation quite aptly characterized by the ACRS as "a poor trade in any enforcement environment." The potential problems created by this proposal are further compounded by the proposed criterion of seven consecutive successful starts as a condition for return to service after a "problem" indication. Here again, a numerical criterion with no known basis is proposed. NUREG/CR-5775 notes that "surveillance tests may have adverse impact on safety because of their undesirable side effects such as initiation of plant transients during testing or wearing-out of safety systems due to testing, as evidenced by the operating experience of the plants" and claims that "the safety significance or risk-effectiveness of surveillance test requirements can be evaluated with explicit consideration of the adverse effects of testing, in addition to the beneficial effects." If NRC research has produced a valid methodology with this capability, why wasn't it applied to this issue to provide a meaningful basis for the proposed restart criteria? We have welcomed the Commission's stated intention to move to performance based regulation: however, enactment of this proposal into rule would set an extremely poor precedent for the implementation of this new approach. Clearly, if performance criteria are to serve as the primary vehicle for determining if we are providing adequate protection of the public health and safety, they should have a logical foundation. This proposed rule amendment has no such basis and in fact, could very well be detrimental to safe operation of our facilities. Finally, we feel that the regulatory analysis for this proposal is a particularly egregious attempt to evade both the spirit and the letter of the backfitting rule, 10CFR50.109. We believe that this judgment is fully substantiated by the detailed evaluation provided in the NUBARG comment letter. An attempt to prepare an appropriate C76\\230

Secretary of the Commission July 10. 1992 Page 3 backfitting analysis might well have had the beneficial effect of exposing the deficiencies of this proposal prior to its publication for public comment. Sincerely. ~~~-- a.; {. Thayer Vice President and Manager of Operations JKT /mma C76\\230

DOCKET NUMBER PR 5--fJ PROPOSED RULE (5 7 Ffl /'/ 5' 14) ~EQ @) GULF STATES RIVER BEND STATION UTILITIES CON.IPANY POST OFFICE BOX 220 ST. FRANCISVILLE. LOUISIANA 70775 "92 JUL -8 p 3 :3 7 AREA CODE 504 635-6094 346-8651 Secretary of the Commission U. S. Nuclear Regulatory Commission Washington, DC 20555 Gentlemen: July 6, 1992 RBG-37119 File Code No. G9.23.1 Gulf States Utilities (GSU) is pleased to comment on the Commission's proposed rule regarding reliability monitoring of Emergency Diesel Generators (EOG), 57FR14514, dated April 21, 1992. GSU disagrees with implementing this proposed rule and the associated Draft Regulatory Guide 1. 9. While the proposed trigger value method is one way to identify EOG degradation, the Individual Plant Evaluation (IPE) is the appropriate mechanism for determining the risk of changes in the availability of safety systems. A performance-based tracking mechanism, using previous operating history as an ongoing input into the IPE, will assure that the safety significance of EOG reliability is continuously addressed during power operations. The draft regulatory guide assumed a value of O. 007 for EOG unavailability, while River Bend Station plant-specific data places that value at 0.028, or four times greater. A scoping PRA reveals that a factor of four improvement in EOG unavailability due to maintenance only decreases Core Damage Frequency (CDF) by 5%. Preliminary PRA calculations using SBO scenarios in 10CFR50.63 indicate that EOG unavailability up to 0.10 have no significant affect on CDF. Further, should compliance with a 0.007 unavailability due to maintenance become necessary, the cost for an additional swing diesel generator is estimated to be greater than $50 million, clearly an expensive modification. In conclusion, GSU believes the proposed rule is unnecessary for the assurance of EOG performance/reliability. The program for testing outlined in the proposed rule would conflict with River Bend's commitments to testing and maintenance and would only lead to decreased EOG availability. JUL 16 1992 Acknowledg'ect by card...........................,..,.,,

,;-:.' COMMiSSIOfl. -*. !::r,v:cf SECilON .L CF THE SECRETARY Gr lHE COMMISSION Document Statistics Pc$lmark Dato 7 /9"2-Coplcs Received __ -'/----,,, ____ _ Add'I Copies Reproduced 7 SP-ecial Distribution "le.T,_Q .... lS"-, -p..,,.(J_ ,..,,,...~=-- - ~--e,cfS-1 7-,

Please see the two attachments included with this letter, which detail reasons GSU disagrees with the promulgation of this rule. GSU appreciates the opportunity to provide comments on this proposed rule. Enclosures Sincerely, L W. H. Odell Manager-Oversight River Bend Nuclear Group

ATTACHMENT 1 LETrER QUESTION/COMMENTS Gulf States Utilities provides the following responses to questions posed in the proposed rule on Emergency Diesel Generator Reliability (10CFR50.63).

1)

2)

The proposed trigger value methodology provides one way of monitoring EDG reliability. This method is useful because it provides a fixed target. However, the NRC requires Individual Plant Evaluation which will allow utilities to assess the affect on Core Damage Frequency of all EDG reliability levels. A performance based tracking mechanism, using previous operating history as an ongoing input into the IPE, will assure that the safety significance of EDG reliability is continuously addressed during power operations. Industry wide EDG performance history evaluations may have some positive impact on EDG reliability. However, each installation of similar equipment is different. The control systems, auxiliary equipment, and the diesel engine foundation are examples of such differences. Industry wide failure experience is available through INPO's NPRDS. Engine specific information is available from the manufacturer and through diesel generator owner's groups for each engine manufacturer. Therefore, the existing industry wide experience base is available to utilities and the creation of another data base specifically for EDG's is not necessary.

3)

The proposed rule will require an unnecessary specialized layer of monitoring of EDG's on to utilities. The maintenance rule will assure that effectiveness of maintenance activities performed and the effectiveness of root cause determinations will improve the reliability of equipment on a plant wide basis. Industry has significantly improved the reliability of EDG' s through NUMARC Initiatives and INPO's PPIP Program. GSU believes that under these circumstances, this proposed rule is unnecessary.

4)

EDG unavailability and EDG reliability are competing goals. In order to have reliable EDG's, maintenance must be performed. It appears that the NRC is taking the position that availability is more important than reliability. The goal of the SBO rule was to improve EDG reliability. GSU believes that EDG availability and reliability can be adequately monitored through the IPE during plant operation and the NUMARC outage guidance provides a means for identifying high risk evolution's during shutdown. No additional regulatory guidance is needed.

ATTACHMENT 2 DRAFf REGULATORY GUIDE DG-1021 COMMENTS Gulf States Utilities has reviewed the Draft Regulatory Guide, DG-1021 and provides the following comments: A. Introduction - Page 2 the last paragraph should also recognize the improvements made by Generic Letter 84-15. B. Discussion - Does not address how DG-1021 treats dedicated diesel generator units (i.e. C. GE BWRs with HPCS DG). Regulatory Positions RP2.1 - Last paragraph appears to indicate that the first test to declare the DG operable does not count as a valid test. RP2.1 appears to state that the next scheduled test or automatic start is the next DG operation that counts. Is this a correct inteipretation? RP2.2.10 - This guide should address the initiating conditions for the HOT Restart Test i.e. after endurance run in RP2.2.9 or after a run long enough to obtain full load temperature conditions. RP3.1 - Requires that EOG records be kept on a per nuclear unit basis whereas, NUMARC 87-00 allows per Nuclear Unit or per EOG unit record keeping. Does RP3.1 supersede or overrule NUMARC 87-00? RP3.2 - Page 19 (First Paragraph) requires that 7 successful weekly tests be completed ' before returning to monthly testing. This duplicates the requirements of RP3.2.2 and one of these sections should be changed to eliminate the duplication. RP3.2 - Page 19 (Third Paragraph) indicates that the NRC assumed that EOG availability exceeds 99. 3 % as a part of the resolution to SBO. This section further assumes that this availability level will be achieved during power operations and during refueling outages. For plants with operating licenses, this most likely constitutes a backfit beyond that analyzed in NUREG-1109. The ability to perform maintenance on DG's especially during outages is necessary. High reliability in EOG' s is only partially achieved through condition monitoring. The ability to fix what is broken is also a concern. On a per nuclear unit basis, an unavailability level of O. 007 equates to about 61 hours per year that the units EOG's may be out of service. Plants with the current versions of Standard Technical Specifications can end up in accelerated testing with as few as 2 failures in the last 20 demands. Depending on the DG unit design and other regulatory requirements (i.e. NUREG-1216), DG unavailability due to scheduled testing and other regulatory requirements can exceed 20 hours per year at a minimum. This leaves little or no time to perform EOG manufacturer required maintenance per the Standard Technical Specifications. Typically, EOG manufacturers base their maintenance recommendations

on previous experience gained from non-nuclear applications, and from other diesels at nuclear power plants. The O. 007 unavailability assumption does not take in consideration the configuration of the plants electrical distribution system. It serves no useful purpose to maintain this level of EDG unavailability if the rest of the electrical distribution system is out of service for maintenance. The NRC has issued a Generic Letter (GL 88-20) to require plants to prepare a Probabilistic Risk Assessments (PRA) for each nuclear plant. The PRA for River Bend indicates that DG unavailability versus Core Damage Frequency can be quantified during power operations. Preliminary calculations using the SBO scenarios in 10CFR50.63 indicate that RBS existing DG unavailability's up to 0.028 have no significant affect on Core Damage Frequency. In order to maintain unavailability at 0.007 or less, a swing diesel unit will be necessary. This will allow a unit to be taken out of service for maintenance and still maintain the NRC mandated unavailability less than 0.007. The estimated cost for the new EDG unit including the building is $40 million. The cost to make modifications to the plant to connect the swing diesel range from $10 million to 30 million dollars. This clearly exceeds the scope of the existing backfit analysis. The existing technical specifications allow the emergency service water pumps to be removed from service without declaring the EDG cooled by that loop inoperable. However, the logic in DG-1021 can also be applied to indicate that the EDG is not available when the emergency service water source is not available. The emergency service water pumps must be tested per ASME Section XI and Technical Specification 4.0.5 every 92 days. More frequent testing may result based on degradation of the pumps. These examples are intended to show that it is unreasonable to impose a 0.007 unavailability requirement without elevating those portions outside the defined EDG boundary in Figure 1 to this same level of unavailability. The electrical distribution system and cooling water pump are necessary for the DG to perform its safety function. Without them, an available DG can do nothing to mitigate the consequences of an accident. RP3. 3 - States that accelerated testing should continue for a nuclear units EDG' s until the statistical basis for the double trigger exceedence is satisfied. It is assumed that weekly testing would apply to all DG's for each nuclear unit. This proposal creates testing to solely satisfy the statistical basis of the SBO Rule Making. Some plants have gained relief from DG testing to reduce the number of failures to acceptable levels. (Ref. NPF-47 Amendment 61). In a worse case scenario, a nuclear unit could have experienced 8 consecutive failures in the last 100 runs. To resolve this double exceedence, 93 EDG tests would have to be conducted. Assuming two diesel generators, one EDG would have to be tested 47 times, the other unit would have to be tested 46 times. The 2

proposed regulatory guide only allows tests to be conducted every 24 hours at a minimum. This means that it would take 47 days to resolve the double trigger exceedence. The proposed changes to 10CFR 50.63 state that the double exceedence must be eliminated in 30 days from occurrence. This is clearly testing for testing sake and will reduce the reliability of EDG's. RP 2.3.1 describes preoperational testing of EDG' s. This portion of the regulatory guide states that 25 failure free tests are necessary to establish that a new EOG with prior operational history is reliable. If accelerated testing is necessary, completion of 25 failure free demands on a per nuclear unit basis should be all that is required. Table 1 Table 1 allows tests 2.2.6 through 2.2.13 to be performed every 10 years. Currently, these tests are performed every refueling outage. This is a positive aspect of the proposed regulatory guide. However, performance of some of these surveillance's should also be required whenever a significant adjustment is made to the generator excitation or governor subsystems. 3

DC,CKET NUMBER r.ft c-0

• 2cPOSED hULE a" (S1 FrLI

..;;...;J-/~S-1_'-/_}_ L0Lt',E i i:.D USHRC July 6, 1992 ST-HL-AE-4145 File No.: G03.11 10CFR50.63 Secretary of the Commission

u. s. Nuclear Regulatory Commission Attention:

Docketing and Service Branch Washington, DC 20555 South Texas Project Units 1 and 2 Docket Nos. STN 50-498, STN 50-499 Comments on Proposed Rule 10CFR50.63, "Loss of All Alternating current Power" Houston Lighting Power Company endorses the comments submitted by NUMARC on the proposed rule 10CFR50.63 regarding reliability of onsite ac power sources.

1. ~~-~

William J. ja. o~rU

Manager, Nuclear Licensing PLW/ag HISC\\92-185.002 A Subsidiary of Houston Industries Incorporated JUL 16 199l Acknowledged by card........ _.".......... "."

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...... -I JUL - 6d 9921rn JS USNHC L-92-200 '92 JUL 10 A9 :07 The Secretary of the Commission U. S. Nuclear Regulatory Commission Washington, D. C. 20555 ATTN: Docketing and Service Branch Re: Florida Power & Light Company Comments on Proposed Rule Loss of All Alternating Current Power The subject revision to the rule, which proposes to establish regulations that would require licensees to test and monitor emergency diesel generator reliability (EDG), was published in the Federal Register on April 21, 1992, ( 57 FR 14514). The Nuclear Management and Resources Council (NUMARC) has submitted comments on the proposed rule. Florida Powe r & Light Company (FPL) endorses the NUMARC comments and submits the following additional comments:

1.

A Rulemaking on EDG Testing Is Not Necessary The goal of Generic Issue B-56 was to raise industry average EDG reliability to 95% or greater. The current industry average, based on performance indicator data through

1991, is about 98%;

therefore, B-56 should be closed. Also, this closure should satisfy any requirements in plant specific Station Blackout (SBO) Safety Evaluation Reports (SER) for EDG reliability up to 95%. The industry Plant Performance Indicator Program (PPIP) is in place and will help ensure that industry average EDG reliability is monitored and remains high. The proposed rule contains several "triggers" (X failures in the next Y demands) that require specific licensee actions. The industry is already committed to EDG triggers in NUMARC Initiative SA. The initiative is sufficient by itself to focus attention on EDG reliability. The NRC appears to be concerned mainly aboµt "outlier" EDGs. A generic rulemaking is not an appropriate vehicle for regulating outlier situations. The Maintenance Rule guidance being developed by the NRC Staff and by NUMARC will address EDGs from both the r eliability and availability standpoints. The proposed EDG rule revision addresses reliability only, and would likely duplicate (and possibly conflict with) the Maintenance Rule. EDG reliability, if addressed beyond existing requirements, should be addressed via the Maintenance Rule. an FPL Group company JUL 1s \\S92. Acknowledged by card"-"-.............. :..

L-92-200 Page Two

2.

Accelerated Testing The most important NRC objective with respect to EDGs should be the reduction of unnecessary accelerated testing. This issue should be separated from the proposed EDG rule revision, and a framework for regulatory relief should be expedited. Unnecessary accelerated testing is counterproductive because it is more likely to reduce the underlying reliability of the diesel generator due to excessive start-up wear. Accelerated testing should therefore be reserved only for diesels that are demonstrated to be problem diesels in order to avoid creating a problem diesel with excessive cold starts. Proposed Revision 3 to Regulatory Guide 1.9, "Selection, Design, and Qualification of Diesel-Generator Units Used as Standby {Onsite) Electric Power Systems at Nuclear Power Plants, 11 calls for accelerated testing after reaching a double trigger as well as after reaching the problem-diesel trigger. It is very unlikely that the problem-diesel trigger will occur before a double trigger. Accelerated testing should be reserved for the case of a problem diesel. 3. Enforcement The proposed rule specifies that a Level 3 violation be imposed whenever a double trigger is reached. The NRC Staff has sufficient enforcement authority under 10 CFR 50, Appendix B, to take action against unreliable EDGs. The NRC should learn from the experience of the original Environmental Qualification Enforcement Policy. Because it was overly prescriptive and overly harsh, it created problems that led to its revisions. Because the triggers are based on small samples, there is more than a small chance that a trigger will represent a "false exceedance," i.e., an innocent EDG with an underlying reliability above the target reliability {either 95% or 97. 5%) will become suspect. Therefore, given the adverse consequences to the utility of enforcement action, a strict enforcement *cliff II should not be used. The regulatory response to a trigger should be carefully applied on a case-by-case basis.

4.

Performance-Based Regulation The Commission has been encouraging industry and the NRC Staff to identify a test case for performance based regulation, i.e., regulation that sets an enforcement threshold and lets each licensee determine what kind of program to implement to avoid

L-92-200 Page Three crossing that threshold. Now that we are more aware of the statistical shortcomings of the proposed EOG rule (sample size too small, high chance of false exceedance of a trigger), we do not believe that an EOG rule is a good test for performance-based regulation. A true performance-based regulation should have clear, objective, pass/fail criteria. Such criteria are not identifiable in situations with inherent statistical uncertainty, as is the case with diesel generator test data. 5. Station Blackout Risk Considerations The contribution to risk (core damage frequency) from Station Blackout (SBO) varies widely form plant to plant. Requirements should not be placed on individual diesels, which are not highly risk significant under the SBO Rule. SBO is a uunit" rule.

Also, the reliability numbers used to determine the SBO coping durations are not necessarily the numbers applicable to the site specific resolution of SBO for each utility per its SBO SER.

For example, per the SBO SER the EOGs at St. Lucie Unit 1 are not required to mitigate SBO at either Unit 1 or Unit 2 and imposing a reliability program on them by revising 10 CFR 50.63 is inconsistent.

6.

Backfit Rule The NRC Staff has concluded that the Backfit Analysis from the 1988 SBO Rule applies to the proposed EOG rule and that a new analysis is not required. This ignores the EOG improvements that have been made and the industry initiatives that have been taken since then. As a minimum, NRC should perform a new backfit analysis that applies specifically to the proposed EOG rule. More detailed comments regarding the backfitting aspects of the proposed rule will be provided by the Nuclear Utility Backfitting and Reform Group (NUBARG). FPL is a member of NUBARG. Very truly yours, io ire c or, Nuclear Licensing REG/MAS/dmb

~ SCE&G Ast:IIIIIICompany South Carolina Electric & Gas Company P.O. Box BB Jenkinsville, SC 29065 (803) 345-4040 The Secretary of the Commission U.S. Nuclear Regulatory Commission Washington, DC 20555 Attention: Docketing and Service Branch Gentlemen:

Subject:

COMMENTS ON DRAFT REGULATORY GUIDE DG-1021 John L. Skolds Vice President Nuclear Operations DOCKETED USNRC

• 92 JUL -9 A11 :22 AND THE PROPOSED RULE FOR 10CFR50.63, LOSS OF ALL ALTERNATING CURRENT POWER, FEDERAL REGISTER, APRIL 21, 1992 (REG 920008 & PR 920014)

South Carolina Electric & Gas Company (SCE&G) has reviewed the Proposed Rule and Draft Regulatory Guide and provides the following comments in addition to the endorsement of the NUMARC comments on the same subject. Specific CODDents on Contents of the Proposed Rule and Draft Regulatory Guide. Proposed Rule a) In the "Enforcement Considerations" Section, the NRC intends to modify 10 CFR 2, APP C, to list reaching the double trigger value as a failure to meet the required corrective actions of 10 CFR 50, APP B, and, therefore, an example of a Severity Level III Violation. The NRC goes on to comment that since the 3/20 warning value exists, the civil penalty could be escalated; and if the NRC views the response to exceeding the double trigger values as inadequate, it would justify a possible daily civil penalty for each day the facility exceeded the double trigger values. These policies seem overly severe and prescriptive to apply to an indicator program that in the 11Monitoring of EOG Performance" Section of the proposed rule, the NRC describes as follows: "Thus, the trigger concept should not be viewed as a statistical estimate of the EOG reliability, but rather as a method to identify the potential degradation of reliability. 11 Severity level and civil penalties should be justified by in-depth consideration of real hazard probabilities and not simply by comparing the number of failures to a trigger value which only indicates the potential for degradation. (fj) JUL 16 ijij, Acknowledged by card.. ~-...............,.....

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The Secretary of the Commission REG 920008 & PR 920014 Page 2 b) In the "Regulatory Analysis" Section of the proposed rule, the NRC states that "The Commission now believes that detailed prescriptive guidance on the content of emergency diesel generator reliability monitoring programs is not warranted," yet it appears that both the Proposed Rule and the Regulatory Guide are prescriptive; furthermore, in light of Item a) above, the consequences of not meeting this program are also prescriptive. c) There seems to be several erroneous references in the publication of the Proposed Rule in the Federal Register that made some of the required actions unclear.

1)

"Monitoring of EDG Performance" Section, Item (3), refers to 50.63(a)(3)(i)(C). However, the proposed published Amendment to 50.63 seems to indicate that 50.63(a)(3)(1i1)(C) should be referenced.

2)

"Enforcement Considerations" Section refers to 50.63(a)(3)(i1)(C) twice and 50.63(a)(3)(ii)(A) once.

However, according to the Proposed Amendment to 50.63, these references should be 50.63(a)(3)(iii)(C) and 50.63(a)(3)(i), respectively.

It is unclear whether the references were in error or if the layout of the Proposed Amendment was in error. Regulatory Guide a) The definition for "Start Failures" needs clarification to explain that, for the purposes of station blackout reliability, the Technical Specification time requirements for reaching rated speed and voltage do not apply. Therefore, a suggestion for the parenthetical statement in the definition is as follows: (The time limit required to achieve specified speed and voltage in specific tests is not considered in determining start failures. Even if the generator fails to reach rated speed and voltage within the precise time required by Technical Specifications or any other test, the start attempt is not considered a failure if the test demonstrated that the generator would start and run in an emergency.) b) Also in the definition for "Start Failures," the last sentence attempts to explain how a maintenance inspection can result in a failure. From discussions held with both the Region and NRR over these situations (but regarding Regulatory Guide 1.108), this statement needs to be expounded upon for the purpose of consistency. The following is a possible replacement for the last sentence: A condition that is identified during the course of maintenance or a maintenance inspection could constitute a valid start demand and failure if: 1) It is determined that the condition definitely existed while the emergency diesel generator was in the standby mode; and 2) It is determined that the condition would definitely have resulted in a start failure if a demand had occurred.

The Secretary of the Commission REG 920008 & PR 920014 Page 3 c) The definition for load-run failures includes the same last sentence with respect to maintenance and load-runs as the definition for start failures. This sentence should also be replaced as modeled above. d) A definition of 11Standby Mode 11 may be helpful. Please consider: Standby Mode - The condition of having the diesel generator--to the best of knowledge--operable, aligned, and ready to perform its designed function. e) The first bullet under the 11Exceptions 11 Section states, 11Spurious operation of a trip that would be bypassed in the emergency operation mode. 11 As discussed in Section 1.8 of the 11Design Considerations 11 Section of the Regulatory Guide, protective trip circuitry other than overspeed and generator-differential-overcurrent can be bypassed, provided sufficient time exists to effectively react to the monitored condition. Also, the bypass circuitry should be capable of testing the status and the operability of the bypass circuits. Therefore, the exception for failures due to signals that are normally bypassed should not be limited to spurious signals, but instead should read: Any operation of a trip that would be bypassed in the emergency operation mode. f) The fourth bullet under the 11Exceptions 11 Section states 11Component malfunctions or operating errors that did not prevent the emergency diesel from being restarted and loaded within a few minutes. 11 This implies a factor of urgency to this situation. It does not seem prudent to rush another start-run attempt during testing or even during a real demand where the malfunctioning diesel is not needed (i.e., one train of power is available and is meeting current demands), but rather to evaluate the situation at a pace conunensurate with the need. Therefore, consider the following revision to this statement: 11Component malfunctions or operating errors that either did not prevent or after evaluation was determined would not have prevented the emergency diesel generator from being restarted and brought to load within a few minutes (i.e., without corrective maintenance or where problem identification did not require complex evaluation). This does not preclude a thorough, and possibly a timely, investigation to assure that the initial diagnosis is correct and the only cause. 11 g) The final paragraph of the 11Exceptions 11 Section is vague and open to subjective interpretation. The issue is based around the condition of when an emergency diesel generator is declared inoperable without having experienced a failure. The following paragraph may more accurately define the exception: Each emergency diesel generator failure that results in the emergency diesel generator becoming inoperable should be counted as one demand and one failure. Regardless of why the emergency diesel generator is declared inoperable, an exploratory test performed on an inoperable emergency diesel generator and any tests run to verify operability (successful or unsuccessful) should not be counted as demands or failures until the emergency diesel generator has been subsequently declared operable.

The Secretary of the Commission REG 920008 & PR 920014 Page 4 Response to the Four Specific Questions Contained in the Federal Register. a) Is there a better way to identify EOG degradation than the proposed trigger values?

RESPONSE

The proposed trigger values are not absolute or certain indicators, especially when considering station blackout duration commitments. Additional consideration could be given to minor repairs which could be completed within the station blackout duration requirements. b) Is there a better method which could utilize industry wide EOG performance history to provide adequate reliability information for plant specific use?

RESPONSE

No response. c) In light of recent industry performance and the future requirements of the Maintenance Rule, is this rule necessary?

RESPONSE

In view of the actions that will be taken in accordance with the Maintenance Rule coupled with the consistency that would be gained by issuing Revision 3 of Regulatory Guide 1.9, it would appear that most if not all of the real reliability gains would be accomplished without the issuance of this rule. Also, the entire rule seems unnecessary due to the lack of evidence that the emergency diesel generator reliability is a problem under existing regulations. d) Should this rule address EOG unavailability?

RESPONSE

Unavailability should not be addressed by this rule. Conclusion SCE&G does not agree with the need, nor is it in favor, of the implementation of the proposed rule. However, even though additional clarification is needed, the Draft Regulatory Guide does offer consistency and clarification regarding EOG testing requirements which are far superior to the subjectivity and confusion that exist in Regulatory Guide 1.108. Please contact Mr. David Haile at 803-345-4322 if you have any questions. DCH:JLS:smd c: See Page 5 Very truly yo~~* ~ ~l~ ~or T. L. $'.t:"<>lds John L. Skolds

The Secretary of the Commission REG 920008 & PR 920014 Page 5 c: 0. W. Dixon R.R. Mahan R. J. White G. F. Wunder General Managers NSRC RTS (PR 920014 & REG 920008) File (811.02, 50.068 & 811.05, 1.9) NUCLEAR EXCELLENCE - A SU... ER TRADITION!

[IE Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402 Mark 0. Medford Vice President, Nuclear Assurance, Licensing and Fuels July 2, 1992 Mr. Samuel J. Chilk Secretary of the Commission ATTN: Docketing and Service Branch U.S. Nuclear Regulatory Commission Washington, DC 20555

Dear Mr. Chilk:

'92 JUL -9 P 4 :Q6 NUCLEAR REGULATORY COMMISSION (NRC) - REQUEST FOR COMMENTS ON THE PROPOSED AMENDMENT TO 10 CFR 50.63, "LOSS OF ALL ALTERNATING CURRENT POWER," AND DRAFT REGULATORY GUIDE DG-1021 The Tennessee Valley Authority (TVA) has reviewed and is pleased to provide comments on the proposed amendment to 10 CFR 50.63, which was noticed in the April 21, 1992, Federal Register (14514) and Draft Regulatory Guide DG-1021. TVA supports the comments on this proposal made by the Nuclear Management and Resources Council (NUMARC) and Electromotive Motor Division-Power Systems (EMO-PS) Owners' Group with exception to Item 1 of Enclosure 2 to NUMARC's specific comments dealing with the 3/20 early warning trigger values reporting and testing requirement. Our position on this issue is identified as Specific Comment 1 in the enclosure to this letter. In addition, the enclosure to this letter provides TVA's specific comments. TVA appreciates this opportunity to respond to this request for comments. Sincerely, Mark 0. Medford Enclosure cc: See page 2 JUL 16 l99l Acknowledged b'i card.. --""'"....,,.....

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I Mr. Samuel J. Chilk Page 2 July 2, 1992 cc (Enclosure): Mr. Aleck W. Serkiz Office of Nuclear Regulatory Research Division of Safety Issue Resolution U.S. Nuclear Regulatory Commission Washington, DC 20555 Mr. B. A. Wilson, Project Chief U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323

ENCLOSURE In light of the requirements of the Maintenance Rule, the proposed regulation appears unnecessary. TVA recommends that the industry be allowed to establish programs as proposed by NUMARC and Owners* groups. Topic 1 Specific comments on the contents of the proposed rule and draft regulatory guide. TVA's Response We believe that the concept of using a small population data is acceptable for the identification of trends which will be used to initiate corrective action; however, we do not believe that it is a sufficiently accurate basis for enforcement action. Adequate enforcement control already exists without adding a separate enforcement statement in the rule amendment. Specific Comment 1 The trigger value of 3/20 is applicable to the performance of any individual emergency diesel generator (EOG) and of all EOGs assigned to a nuclear unit, while the trigger value of 4/25 is applicable to individual EDGs. Yet, both trigger values have similar reporting requirements. As published, this rule requires duplicate reporting. TVA recommends that the 3/20 be an early warning indicator. and no reporting requirement is needed. The 4/25 trigger value will remain as a "problem diesel" identifier. However, the corrective action should include the necessary number of tests to ensure the problem is resolved. Yet, no specific number of tests should be identified. The amount of testing should be left up to the utility and based on the specifie f~ilure situation. Specific Comment 2 Recovery from the "double trigger" condition should not be based on an accelerated testing method. As the industry and NRC discovered in the last ten years, accelerated testing is a major cause of diesel unreliability. TVA recommends that the approach identified in Sections 0.2.4.3 and 0.2.4.5 of NUMARC 8700 Appendix D be used as the recovery method from the "double trigger" condition. Specific Comment 3 Table 1 (Preoperational and Surveillance Testing) identifies Tests 2.2.6 through 2.2.13 to be conducted every ten years. TVA performs tnese tests every refueling outage in accordance with the requirements of Institute of Electrical & Electronic Engineers {IEEE) 387. TVA recommends that NRC resolve this difference with the IEEE 387 committee. Topic 2

a.

Is there a better way to identify EOG degradation than the proposed trigger values?

b.

Is there a better method which could utilize industrywide EOG performance history to provide adequate reliability lnformation for plant specific use?

c.

In light of the recent industry performance and the future requirements of the Maintenance Rule (10 CFR 50.65}, is this proposed rule necessary?

d.

Should this proposed rule also address EOG unavailability? TVA's Response

a. The trigger value method seems to be an adequate method of monitoring for trend indication showing potential degradation of EOG reliability.

We are not aware of a method that would work better; however, as we have previously stated, the amount of data is not sufficient to draw accurate conclusions regarding specific reliability numbers.

b.

We are not aware of a method using industrywide performance history which would be better.

c.

EOG system reliability is high. The industry is implementing consistent programs based on the NUMARC guidelines to monitor reliability and ensure that it remains sufficiently high. Maintenance Rule 10 CFR 50.65 should provide sufficient regulatory control without unnecessarily restricting the industry. Therefore, this rule is not necessary.

d.

Maintenance Rule 10 CFR 50.65 addresses the issue of balancing reliability and unavailability. This rule should not address unavailability. Topic 3 For those utilities which have progressed through the Individual Plant Examinations (IPE} to the point where they can provide appropriate insights, we request a characterization of the relative and absolute impact (in terms of core damage frequency (COF} and likelihood of a large release) of the Station Blackout (S80} sequence on overall plant risk. In addition, for utilities where the information is easily retrievable, we request a determination of the contribution of EOG reliability to SBO risk as well as an indication of the reduction in COF, if any, due to the actions taken in response to the SBO rule. Please note that these requests for information are not intended to require the expenditure of significant resources. TVA's Response The IPEs for Sequoyah, Browns Ferry, and Watts Bar Nuclear Plants have not progressed to the point where results can be provided. The requested results will be available after submittal of the IPEs for these plants. Topic 4 Por those utilities which have EOG accelerated testing specified in their technical specifications, we request information regarding any implementation difficulties caused by differences between the technical specification requirements and the proposed rule and draft regulatory guide, e.g., differences between Regulatory Guide 1.108 technical specification failure definitions and the failure definitions in the draft regulatory guide. TVA' s Response We have accelerated testing specified in our technical specifications. The differences in definitions cause some confusion in implementation. We anticipate revising our technical specifications when this issue is settled to resolve these differences.

UV\\.lf\\C I NUMDCM PR PROPOSED RULE 5 0 {f7Ffl l45J'i} 1UELECTRIC Log II TXX-92320 File Ii 10186 909.5 Ref. II 10CFR50.63 July 6, 1992 William J. Cahill, Jr. Group Vice Pre3ident Secretary of the Commission U. S. Nuclear Regulatory Commission Attn: Docketing and Service Branch Washington D. C. 20555

SUBJECT:

Gentlemen: COMANCHE PEAK STEAM ELECTRIC STATION (CPSES) COMMENTS ON PROPOSED AMENDMENT TO THE STATION BLACKOUT RULE, 10CFR50.63 AND DRAFT REVISION 3 OF NUCLEAR REGULATORY COMMISSION (NRC) REGULATORY GUIDE 1. 9 DOCKElED USNRC '92 JUL -7 A11 :13 On April 21, 1992, the NRC published a notice in the Federal Register inviting public comments on a proposed amendment to the Station Blackout (SBO) Rule and a proposed revision 3 to Regulatory Guide 1.9 entitled, "Selection, Design, Qualification, Testing, and Reliability of Diesel Generator Units used as Onsite Electric Power Systems at Nuclear Power Plants." The draft Regulatory Guide, identified as DG 1021, concerns Emergency Diesel Generator (EOG) reliability. TU Electric has reviewed the proposed amendment to the SBO rule and draft Regulatory Guide and provides comments on the purposed rule in Attachment 1, and comments on the draft regulatory guide in Attachment 2. VPC/ds Attachments Sincerely, William J. Cahill, Jr. By,fi<<!:!.~ Generic Licensing Manager JUL 16 ~ Acknowledged by card..-;............... -,...,..... 400 N. Olive Street L.B. 81 Dallas, Texas 75201

u.s 1* 1,.,:GULATORY COMMISSIO~ i):_. *-*- -'11\\,u & SERVICE SECTION (+; :cE OF THE SECRETARY Of THE COMMISSlGN Document Statistics Pos~11ark Date 2 L6 /q J_ Copies Received __ Aden Copies Reproduced, __ )..__ ___ Special Distri~tion /1.IllSj P/2{4 ) ~ ILi?., to TXX-92320 Page 1 of 1 TU ELECTRIC COMMENTS ON THE NRC'S PROPOSED AMENDMENT TO 10CFR50.63. STATION BLACKOUT RULE (1) The proposed rule indicates that the EOG target reliability values of 0.95 and 0.975 are per nuclear unit versus per EOG. This is inconsistent with the original SBO rule. (2) The proposed rule indicates that the 3/20 trigger should be applied to the performance of any individual EOG and to all EDGs at a nuclear unit. In addition, the proposed rule indicates that upon reaching a 3/20 trigger, a 30 day written report is required to be submitted to the NRC. Applying the 3/20 trigger to the individual EDGs is inconsistent with NUMARC Initiative 5A which all of industry has committed to implement. Initiative 5A requires application of the 3/20 trigger per nuclear unit instead of per EOG. In addition, a written report to the NRC seems premature since exceeding the 3/20 trigger is an early warning. The 3/20 trigger serves as an anticipatory trigger to give utilities an opportunity to take appropriate steps to prevent occurrence of a degraded EDG. The proposed reporting requirement is redundant to the 10CFR50.72 and 73 (LERs) reporting requirements and will impose an additional burden without any realized benefit. TU Electric recommends that logging this data or including a statement in the LER discussing the SBO impact of the EDG failure seems be considered. (3) For many utilities, implementation of the 4/25 trigger would require an amendment to the facilities operating license with a Technical Specification change. TU Electric recommends that additional guidance be provided in the rule regarding the NRC's methodology for expediting and processing these changes. Per the current NRC review process for license amendment requests, since the 4/25 trigger is not required to safely operate the plant, NRC review time could be as long as 18 to 24 months, unless the NRC provides guidance for a generic Technical Specification change including a No Significant Hazard Consideration and a proposed approval schedule in the proposed rule or regulatory guide implementation section. (4) Requiring notification of the NRC Operations Center within 4 hours after exceeding a double trigger value seems inappropriate, and inconsistent with other occurrences that require 4 hour notifications. If an EDG failure occurs which results in exceeding a double trigger, a 4 hour notification will be made consistent with 10CFR50.72 and 73 for that EDG failure and therefore, may not be necessary for exceeding a double trigger. TU Electric recommends that consideration be given to revising the existing written report requirements to reduce the reporting burden on licensee. Inclusion of a statement in the written report that the EOG failure also resulted in exceeding a double trigger value, noncompliance with the SBO rule and a statement as to why it is okay to still operate may be adequate. Currently, EOG failures are reported to the NRC per 10CRF50.72 and 73, or Technical Specification, and to INPO. To add an additional reporting requirement for a single event may become cumbersome and confusing and does not appear to be necessary. to TXX-92320 Page 1 of 5 TU ELECTRIC COMMENTS ON DRAFT REVISION 3 OF NRC R.G. 1.9 (1) Proposed revision 3 to NRC Regulatory Guide 1.9 appears to be a significant backfit not considered in NUREG-1109, which was the regulatory/backfit analysis for USI A-44, wstation Blackoutw.

a.

Many utilities are committed to the original or earlier revisions of Regulatory Guide 1.9. CPSES is committed to the original version (3/10/71) of Regulatory Guide 1.9. This draft is more extensive and would require more resources in terms of cost, schedule and manpower. It appears that requiring all licensees to comply would impose a backfit to varying degrees on every licensee.

b.

Many utilities are not committed to or are committed to earlier versions of the IEEE standards cited in this draft Regulatory Guide. CPSES is committed to IEEE 387-1977 and IEEE 308-1971. Requiring all licensees to comply with such standards may impose a backfit to varying degrees on licensees. (2) TU Electric recommends that a separate regulatory analysis be prepared taking into account the additional requirements that may be imposed by draft revision 3 of Regulatory Guide 1.9, for example, additional reporting and testing requirements. (3) The proposed amendment to the rule states that, wlicensee's were required to select EOG target reliability values in determining the specific station blackout duration required by the Station Blackout rule (SBO) 10CFR50.63(a). However, the SBO rule did not require licensee's to monitor and maintain these reliability values. As a result, the Commission has determined that new requirements are needed for appropriate EOG testing and monitoring against EOG performance based criteria.w In addition, draft Regulatory Guide 1.9, Rev. 3, states on page 2 that wThe resolution of USI A-44 established a need for an emergency diesel generator (EOG) reliability program that has the capability to achieve and maintain the EOG reliability levels in the range of 0.95 per demand or better.w Given the fact that the industry, and each utility within the industry, has already achieved and maintained an EOG reliability of 0.98, there does not appear to be a need for rulemaking or additional regulation/guidance in this area. Technical Specifications seem to provide sufficient assurance that EOG reliability will be maintained. It seems that specific regulatory concerns can be resolved without imposing this guidance. to TXX -92320 Page 2 of 5 (4) If the proposed EDG Reliability Program is implemented as proposed, TU Electric recommends that consideration be given within the proposed rule or draft regulatory guide to utilities to use the program as justification for reductions in scheduled preventative maintenance as well as for identification of maintenance needs. For example, the existing Transamerica Delaval, Inc. (TDI) program should be considered as either an acceptable alternative to compliance with this Regulatory Guide or this guide should be used, where applicable, in lieu of all or portions of the TDI program. (5) Design Consideration 1.4: (6) ( 7) Exception to the 75% voltage decrease value should also be granted to account for transformer magnetic inrush current. Design Consideration 1.5: This regulatory position appears to conflict with current technical specifications, Generic Letter 84-15, and Section 2 of this draft Regulatory Guide. In the current Technical Specifications, wcold fast startw tests are required only on 184 day or refueling intervals, not every test. In addition, to prevent EDG wear and stress, every intentional surveillance start of an EDG should allow pre-warming and pre-lubrication, even if done manually, such as required for the turbocharger bearing of a TDI EDG. The simulation of actual demand conditions is performed on a 184 day cycle per position 2.3.2.2. Is this statement implying that automatic features must be installed to slow-start/gradually load the unit on a monthly basis as described in 2.3.2.1? Most EDG's do not have a slow-start capability and several utilities manually load the unit gradually for monthly testing. Design Consideration 1.7.2: wFirst Out* capability requirements may necessitate design changes in many plants. The recommendation helps speed root cause determination but will add to the cost of initial implementation. A wfirst-outw lockin feature for~ EDG protective trip, especially in the control room, is not a normal configuration. Investigation at the local panel is normally required since a consolidated remote alarm goes to the control room. Also, at the local panel the "first-out" feature is usually only for a limited set of key alarms or split between the engine and generator alarm sets. to TXX-92320 Page 3 of 5 (8) Test Description 2.2: ( 9) This position may result in procedure and design backfits. This position could prohibit non-standard alignments during routine tests. For example, a current practice is to isolate certain portions of redundant subsystems in order to test the operability of the remaining subsystems. To accomplish ASME Section XI testing of air start valves, breakers and valves are manipulated in what could be considered a non-standard configuration. Modifications may be required to satisfy this position which would be a backfit specific to this Regulatory Guide and not covered by NUREG-1109. Test Description 2.2.2: "Temperature equilibrium" is an undefined term. (10) Test Descriptions 2.2.2. 2.2.8. 2.2.9. 2.3.1 : (a) Demonstration of load-carrying capability should utilize the design load of the plant instead of the 90 to 100 percent of continuous (nameplate) rating of the EOG. Testing the continuous rating of the EOG should only be required during preoperational testing when the capacity of the EOG is being demonstrated. Testing at the continuous rating of the EOG where the design load is less than the continuous rating provides minimal benefit and increases wear on the engine. Likewise, demonstration of the 2-hour short-term rating if design loads are less that 90 to 100 percent of continuous rating provides minimal benefit. Two-hour short-term testing should be at 110% of design load or at a maximum of 110% of the continuous rating, whichever is lower. {b) This proposed requirement, as written, does not seem to allow the use of the manufacturer's recommended warm-up procedures (i.e., gradual loading). Since the purpose of this test is to demonstrate the ability of the unit to carry a load for a sustained period of time and not to demonstrate automatic sequencer type loading, TU Electric recommends that this requirement take into consideration the manufacturer's recommended warm-up procedures for this test. (c) Not all Technical Specifications require the proposed 2-hour portion of this test. If the expected load is less than the continuous rating, the 2 hour portion of this test may not need to be performed. Under these circumstances, performance of the test may actually reduce EOG reliability. to TXX -92320 Page 4 of 5 (d) Operational experience shows that engine operation less than 90-95% of rated nameplate power yields a significant reduction in the wear rate of critical components. Therefore, not testing at the short term rating or nameplate rating, but instead at a value greater than design load but less than 90-95% of nameplate rating, could significantly increase EDG reliability. (11) Test Description 2.2.10: The hot restart test seems to require functional capability at design load temperature instead of full load temperature based on the same argument used in Item 7 above. (12) Test Description 2.2.12: The requirement for demonstration that trips are automatically bypassed could result in intentionally challenging safety systems to show proper operation. This would be undesirable. (13) Test Descri ption 2.3.2.1: TU Electric recommends that the Staff considers whether or not monthly testing of EDG's could be waived for a set time prior to the 6 and 18 month surveillances. Testing prior to these surveillances may be unnecessary and may add wear and stress that could reduce the available life of the equipment. (14) Test Description 2.3.3: Would accelerated testing utilize the starting criteria of 2.2.1 or 2.2.3? TU Electric recommends that the Staff consider the use of "soft starts" per Section 2.2.1 for performance of the weekly surveillances instead of fast starts per 2.2.3. This position seems to need additional clarification. (15) Test Description 3.2: The proposed rule and draft regulatory guide does not appear to have provided enough guidance regarding how to count EDG demands. For example, does 50 demands equal 50 start demands and 50 load demands? The NUMARC 87-00 guidance is very specific in this area. to TXX-92320 Page 5 of 5 (16) Test Descri pt ion 3.3: The recovery actions for exceeding a double trigger value somewhat unclear. TU Electric recommends that additional guidance be provided such that it is clear to licensees which EDG should be subjected to accelerated testing. For example, failures could be equally split between the EDGs resulting in equal testing or testing of the EOG with the better/worst numbers. It seems that accelerated testing should only be applied when the 4/25 trigger is reached. The general agreement of EDG experts is that accelerated testing puts unnecessary wear and stress on the EDG, results in a net reduction in equipment availability and leads to premature failure. The SAIC report to the NRC on EDG reliability program review guidance also supports this view.

1 1400 L STREET, N.W. OOCKETLD USNRC

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CHICAGO OFFICE FREDERICK H. WINSTON (1853-1886) SILAS H. STRAWN (1891-1946) WASHINGTON, D.C. 20005-3502 (202) 371-5700 '92 JUL -7 35 WEST WACKER DRIVE A1 (}';'t';),Gp, ILLINOIS 80801 '-(ti 2) 558-5800 FACSIMILE (202) 371-5950 July 6, 1992 Mr. Samuel J. Chilk Secretary of the Commission U.S. Nuclear Regulatory commission Washington, D.C. 20555 ATTN: Docketing and Service Branch l f- ~ ! I

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175 WATER STREET , t \\NEW YORK, NY 10038-4981 t,. l, (212) 28e-2soo Re: Solicitation of Public comments on Proposed Rule Regarding the Reliability of Emergency Diesel Generators, 57 Fed, Reg. 14 1 514

Dear Mr. Chilk:

These comments are submitted on behal!J of the Nuclear Utility Backfitting and Reform Group ("NUBARG"), in response to the NRC's proposed amendment to the station blackout ("SBO") rule, 10 C.F.R. § 50.63. The amendment would add requirements for monitoring and maintaining emergency diesel generator ("EDG") reliability at nuclear power plants. For reasons detailed below, NUBARG believes that a backfitting analysis is required pursuant to the Commission's backfitting rule, 10 C.F.R. § 50.109, for the proposed regulation. Contrary to the assumption in the proposed rule, the backfitting analysis performed in 1988 in connection with the original SBO rule does not satisfy the requirements of Section 50.109 as they apply to this proposed rule. Moreover, the proposal does not fall within the compliance exception to the backfitting rule, 10 C.F.R. S 50.109{a) (4). The proposed regulation contemplates a framework of new requirements not included in the 1988 analysis or in the SBO rule. In view of current licensee EDG reliability programs, the actual EDG reliability levels that have been achieved and the promulgation of the maintenance rule, 10 C.F.R. § 50.65 with its emphasis on maintenance standards, NUBARG does not believe the proposed rule is justifiable under the standards of Section 50.109. 1/ NUBARG consists of 22 nuclear utilities (listed in Attachment A hereto), each of which owns or operates a power reactor licensed by the NRC.

JUL 16 19~l Acknowledged by card......,.. nac****

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U.S. ;>-1tlCLEAR REGULATORY COMMISSIOr-OCC:tFTING & SERVICE SECTION CfflCE OF THE SECRETARY Of THE COMMISSION Document StaUslies Postmaik Dale 2 I 6 /7?- 1::). 0 Copies ReceiV9d. __ Md'l Copes Reproduced __,_1 __ __,__ spec1a1 Dlltritlu.tlOn,z L o~ ra Y2y £-R v-L~ I Z,

WINSTON & STRAWN Mr. Samuel J. Chilk July 6, 1992 Page 2 The Backfitting Analysis For The SBO Rule Does Not satisfy The standards Of section so.109 As They Apply To The Proposed Rule The backfitting rule provides that the Commission may require the backfitting of a facility only when it determines, based upon a backfitting analysis (as described in Section 50.109 (c)), that there is a "substantial increase" in overall protection of the public health and safety and that the costs of implementation are justified II in view of this increased protection." 10 C.F.R. § 50.109(a) (3). In the proposed rule, the Staff expresses the view that "the backfit analysis for the Station Blackout rule essentially enveloped the requirements of this proposed r ule" ( 57 Fed. Reg. a t 14,517). A review of the station blackout rule and the associated backfitting analysis, however, indicates that the NRC did not contemplate the framework of requirements now proposed to test and monitor EOGs against specified criteria and to report to NRC and perform corrective actions where EOG reliability appears to be deteriorating. As the NRC recognizes in the new proposed rule, "the station blackout rule did not require licensees to monitor and maintain (EOG] reliability values." 57 Fed. Reg. at 14,514. The notice accompanying the final SBO rule only outlines the "elements" of a program for EOG reliability in the most general terms. 53 Fed. Reg. 23,203, 23,218. The blfkfitting analysis for the SBO rule was presented in NUREG-1109. A review of that backfitting analysis shows that an EOG reliability program was not specifically considered as part of the regulatory action being justified. NUREG-1109 noted (at pages 26-27) that guidance on diesel generator reliability programs was under development as part of the resolution of Generic Issue B-56, but did not offer a specific cost-benefit justification for new EOG reliability requirements. NUREG-1109 (Table 10, page 20) referred to 12 reactors "needing modifications" to improve EOG reliability or to "requalify" an EOG, and assessed estimated costs associated with these actions. It is not clear how these costs are related to the costs of implementation under the proposed rule, which would apply to all currently operating nuclear power plants. V NUREG-1109, "Regulatory/Backfit Analysis for the Resolution of Unresolved Safety Issue A-44, Station Blackout" (June 1988).

WINSTON & STRAWN Mr. Samuel J. Chilk July 6, 1992 Page 3 Even if NUREG-1109 had included a specific analysis of EOG maintenance and monitoring programs as contemplated by the proposed rule, it would now be outdated. The backfit analysis for the SBO rule was prepared in 1985-1988. Since then, a number of actions have been taken which significantly reduce the risk attributable to station blackout and hence the potential benefits of NRC-required reliability monitoring programs. For example, licensees have proposed and implemented modifications to achieve compliance with the SBO rule, and the NRC staff has r ecently completed its safety evaluations of these matters and issued safety evaluation reports for all currently operating plants. Licensees universally have undertaken EOG reliability programs which are documented by the NRC and which are consistent with the approved guidelines for the SBO rule. In addition, the Commission has since i ssued the maintenance rule, and the Sta ff is well on its way to completion of major team inspections of plant electrical distribution systems -- which include inspections of EOG functional operability and related maintenance programs. Thus it is not clear that NUREG-1109 can be used to demonstrate the extent to which the proposed rule provides a "substantial" increase in public safety, or that the co~s of implementation of the proposed requirements are justified. In short, the NRC has not given credit for the level of safety that licensees have reached since the publication of NUREG-1109 and the SBO rule. It is NUBARG's position that a specific backfitting analysis is required in order to justify the current proposed rule. The Proposed Rule Does Not Fall Within The compliance Exception To The Backfittinq Rule The NRC states that, even if the backfitting analysis for the SBO rule did not "envelope" the proposed new requirements, the "compliance" exception to the backfitting rule, 10 C.F.R. § 50.109(a) (4) (i), is applicable. 57 Fed. Reg. at 14,517. A proposed backfit falls under the compliance exception to the backfitting rule if it is necessary to bring the facility into compliance with "a license or the rules or orders of t he Commission." 10 C.F.R. § 50.109(a)(4)(i). The use of t he compliance exception is discussed in the 1985 Statement of The Commission recognizes that most licensees "were already performing some type of reliability monitoring" and "does not believe that licensees have reduced their monitoring" since the SBO rule was published. 57 Fed. Reg. at 14,516.

' Y WINSTON & STRAWN Mr. Samuel J. Chilk July 6, 1992 Page 4 Considerations for 10 C.F.R. § 50.109 which states that "the compliance exception is intended to address situations where the licensee has failed to meet known and established standards of the Commission because of omission or mistake of fact *** new or modified i nter pr et ations of what constitutes compliance would not fall within the exception and would require a backfit analysis **** 50 Fed. Reg. at 38, 103 (emphasis added). In the case of this proposed rule, there is no established requirement regarding the maintenance and monitoring of EDG reliability with which to comply. In the Notice of Proposed Rulemaking, the Commission states that "the station blackout rule did not require licensees to monitor and maintain these (EDG] reliability values." 57 Fed. Reg. at 14,514. Further, in a Staff Requirements Memora ndum dated June 26, 1991, the Commission indicated that at present there is no "firm legal basis" for imposing guidelines on or securing enforceable commitments from licensees to provide for a specific EDG reliability program. In the acknowledged absence of an existing regulatory basis, it is difficult to see how this proposed rule could be characterized as a compliance backfit. If indeed it could have qualified under the compliance exception, it seems unlikely that the Commission would have seen the need to recommend rulemaking to require specific EDG reliability programs. The Proposed Rule Lacks AD Adequate Technical Basis If a backfit analysis were performed in connection with the proposed rulemaking, we believe it would demonstrate that there is no substantial increase in the overall protection of the public health and safety to be derived from the proposed backfit. As indicated in footnote 3, the Commission recognizes that most licensees are already performing some type of reliability monitoring. In fact, all nuclear utilities have implemented the "trigger value" approach, set forth in NUMARC Initiative SA, for monitoring and maintaining EDG reliability. Because the actions that would be required under the proposed rule are essentially being taken by all affected licensees, no safety benefit would be achieved by promulgation of the proposed rule. The Advisory Committee on Reactor Safeguards (ACRS) emphasized this point in a letter to NRC Chairman Selin, dated December 20, 1991, in which it concluded that "the proposed rule amendment is unnecessary to ensure adequate diesel generator reliability" and "should not be promulgated." Likewise, the NRC

WINSTON & STRAWN Mr. Samuel J. Chilk July 6, 1992 Page 5 Staff has agreed that "there does not now appear to be a problem with emergency diesel generator reliability industry wide." See SECY-92-025, "Resolution of Generic Safety Issue B-56 'Diesel Generator Reliability,'" dated January 21, 1992, Enclosure 4. Further, the Staff has acknowledged that "the need for this proposed revision can be questioned * (and that) Industry initiatives in combination with the requirements of Appendix B to 10 CFR 50 and the guidance in Regulatory Guide 1.155 might *** be sufficient." Id. Not only have licensees implemented EOG reliability monitoring programs, but industry monitoring data show that those programs and eff ective maintenance activities have resulted in industrywide EOG reliability levels significantly higher than those sought t o be a chieved under the propose d rule. I n a l ette r to NRC Chairman Selin, dated May 19, 1992, the ACRS reported, after having reviewed INPO data on actual industry EOG experience for the years 1988-1990, that the "industry average for those three years is better than 99. 5 percent reliability for start and 99 percent reliability for load." Thus, licensees are not only performing the actions which the proposed rule would require, but have already met and exceeded the safety objectives (i.e., maintenance of target reliabilities of 0.95 and 0.975) of the proposed rule. These facts run counter to the NRC's conclusion that the proposed testing and monitoring requirements will provide a substantial increase in the overall protection of the public health and safety

• Attachment

.. ~ Nicholas s. Reynolds ~ Daniel F. Stenger U Jan A. MacGregor Counsel to the Nuclear Utility Backfitting and Reform Group

NUBARG Members Carolina Power & Light Company Cleveland Electric Illuminating Company Commonwealth Edison Company ATTACHMENT A Entergy Operations, Inc. (representing Arkansas Power & Light, System Energy Resources, Inc., and Louisiana Power & Light) Florida Power & Light Company Florida Power Corporation Nebraska Public Power District New York Power Authority Niagara Mohawk Power Corporation Northeast Utilities Pennsylvania Power & Light Company Philadelphia Electric Company Portland General Electric Company Rochester Gas & Electric Corporation Texas Utilities Toledo Edison Company Washington Public Power Supply System Yankee Atomic Electric Company (representing also Public Service Company of New Hampshire, New Hampshire Yankee Division, Maine Yankee Atomic Power Company, and Vermont Nuclear Power Corporation) 1/1/92

DOCKc: I NUMtJl::H PR r o PROPOSED RULE...:..:.::~ -:7-- (£' 7 F f{ IL/ S" /'/ J Entergy Operations, Inc. P.O. Box 31995 -===- ENTERGY DOCKEiED USNRC

• 92 JUL -7 P2 :54 July 2, 1992 Mr. Samuel J. Chilk Secretary of the Commission U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Attention:

Docketing and Service Branch JdCKSOr' MS 39286-199b Tel 601 984 9740 John R. McGaha up rmK.:r" vWJJl-'V'

Subject:

Comments on Proposed Revision to 1 O CFR 50.63, "Loss of All Alternating Current Power" and Draft Regulatory Guide DG-1021 CNRO - 92/00055

Dear Mr. Chilk:

Entergy Operations, Inc. has reviewed the proposed revision to 1 O CFR 50.63 as published in the Federal Register on April 21, 1992 (57 FR 14514-14518) and the related draft Regulatory Guide DG-1021 ("second proposed revision 3 to Regulatory Guide 1.9" dated April 1992). We are enclosing comments on the behalf of Arkansas Nuclear One Units 1 & 2, Grand Gulf Nuclear Station, and Waterford 3 Steam Electric Station. The proposed rule revision is intended primarily to incorporate the diesel generator reliability assumptions used in the original Station Blackout (SBO) Rule into the Code of Federal Regulations. Certain portions of the proposed rule revision and draft Regulatory Guide appear to improve current requirements for some of our plants. We feel that such improvement would be valuable and should be pursued. However, we are concerned that this proposed rule revision is fundamentally redundant to both the new Maintenance Rule (10 CFR 50.65) and plant-specific commitments related to diesel generator reliability programs the NRC staff is actively pursuing through Safety Evaluation Reports on SBO submittals. The rule revision also appears to be based on current industry diesel generator performance in spite of industry initiated improvements in off-site power availability recognized by the NRC such as those documented in EPRI/NSAC report NSAC-182 "Losses of Off-Site Power at U.S. Nuclear Power Plants Through 1991 ".

U.S. !~UCLC1.R ':f-G'J!.ATORY COM~.AISSIO~ C,:.;Ct~c*t '* *:::' li SfHVICE SE "~: r!r~~1 o:**, '!Cl: Or.! !-!f. SECRETMT! Or THE C C:~.1,:1'l.S:/1rJ

Comments on Proposed Revision to 1 O CFR 50.63 and Regulatory Guide DG-1021 July 2, 1992 CNRO-92/00055 Page 2 of 3 We are also concerned that prescriptive, redundant rulemaking may have a long-term negative impact on industry initiatives for self-improvement. The imposition of such rulemaking, even though the industry has voluntarily improved performance to levels recognized by the NRC as acceptable, would appear to be a discouragement to such voluntary efforts in the future. The proposed rule revision appears to have an inadequate regulatory analysis as required by 10 CFR 50.109. There is no actual analysis for the proposed revision; instead it is stated that since the original SBO Rule was based on assumed diesel generator reliabilities, the backfitting analysis for the original rule applies to the proposed revision. We do not feel that the original SBO Rule backfitting analysis adequately addresses this proposed revision. Additional specific comments are attached for your consideration. Attachment 1 addresses the proposed revision to 1 O CFR 50.63, including the four questions posed in the Federal Register notice (at 57 FR 14515). Attachment 2 addresses draft Regulatory Guide DG-1021. We provided input to NUMARC and NUBARG on this subject and endorse their comments in addition to those provided here. We appreciate this opportunity to express our views on this matter. If you have any questions or desire additional information, please contact this office. tit Sincerely, JRM/hek attachment cc: (See Next Page)

Comments on Proposed Revision to 10 CFR 50.63 and Regulatory Guide DG-1021 July 2, 1992 CNRO-92/00055 Page 3 of 3 cc: Mr. T. W. Alexion Mr. A. P. Barkhurst Mr. N. S. Carns Mr. W. T. Cottle Mr. S. D. Ebneter Mr. D. C. Hintz Mr. A. D. Martin Mr. J. L. Mathis Mr. P. W. O'Connor Ms. S. A. Peterson Mr. N. S. Reynolds Ms. L. J. Smith Mr. W. F. Smith Mr. D. L Wigginton Central File (GGNS) DCC (ANO) Records Center (W-3) Corporate File [3]

Comments on Proposed Revision to 1 O CFR 50.63 and Regulatory Guide DG-1021 July 2, 1992 to CNRO-92/00055 Page 1 of 2 SPECIFIC COMMENT INFORMATION REGARDING THE PROPOSED REVISION TO 10 CFR 50.63 The following comments are provided by Entergy Operations on behalf of Arkansas Nuclear One Units 1 & 2, Grand Gulf Nuclear Station, and Waterford 3 Steam Electric Station, although not every comment is applicable to each of these units: Enforcement Considerations - The portion of the draft proposed rule revision indicating that every instance of a reporting problem or exceeding 'double triggers' is a Level Ill violation should be deleted. Each instance of such problems should be evaluated on its individual merits using existing enforcement criteria. The following items address the questions posed in the Federal Register notice concerning the proposed revision (at 57 FR 14515): "Is there a better way to identify EOG degradation than the proposed trigger values... ? 11 Trigger values may not be the most accurate method but do appear to be the simplest. Although actual reliability may not be completely characterized by trigger values, the specific values in the Regulatory Guide appear to be generally reasonable. "Is there a method... which could monitor EOG reliability... which might improve diesel reliability assessment [?]" Since there are numerous diesel designs used throughout the industry (each with different control, support, and auxiliary systems), there may not be a single better method to provide adequate reliability information. However, this issue should be addressed through 1 O CFR 50.65, the Maintenance Rule, rather than through a separate rulemaking applicable only to diesel generators.

Comments on Proposed Revision to 1 O CFR 50.63 and Regulatory Guide DG-1021 July 2, 1992 to CNRO-92/00055 Page 2 of 2 "... is this proposed rule needed to provide continued confidence in the reliability of EDGs... ?" We wish to note that the draft rule revision and Regulatory Guide do contain some positive changes in previous NRC positions, such as those related to accelerated testing and surveillance intervals. These items should be pursued. However, Entergy Operations does not feel that the actual revision to 10 CFR 50.63 currently proposed is necessary due to:

• 1 O CFR 50.65, the Maintenance Rule, which will result in performance based monitoring of EDG reliability without additional SBO rulemaking.
• The plant-specific commitments regarding diesel generator reliability programs per Regulatory Guide 1.155 section 1.2 which are now being actively sought by the NRC staff through Safety Evaluation Reports on the SBO Rule submittals. Additional EDG monitoring and reliability requirements appear redundant and unnecessary.
• The NRC recognition that the existing levels of EDG performance established by the industry through existing self-initiatives, commitments, and requirements such as Technical Specifications already meet or exceed the necessary levels of performance.
• EPRI/NSAC report NSAC-182, "Losses of Off-Site Power at U.S. Nuclear Power Plants Through 1991 ", shows the improvement in the reliability of off-site power in the industry which may reduce the probability of SBO events.

"... views on the need for this rule to address unavailability." Although unavailability is an important issue, it does not appear prudent to address it concurrent with the other issues involved in 10 CFR 50.63. If necessary, this issue should be considered related to 1 O CFR 50.65, the Maintenance Rule, or the Technical Specification Improvement Programs.

Comments on Proposed Revision to 10 CFR 50.63 and Regulatory Guide DG-1021 July 2, 1992 to CNRO-92/00055 Page 1 of 3 SPECIFIC COMMENT INFORMATION REGARDING REGULATORY GUIDE DG-1021 ("Second Proposed Revision 3 to RG-1.9" Dated April 1992) The following comments are provided by Entergy Operations on behalf of Arkansas Nuclear One Units 1 & 2, Grand Gulf Nuclear Station, and Waterford 3 Steam Electric Station, although not every comment is applicable to each of these units:

1.

General - The use of Regulatory Guide DG-1021 appears to force compliance with IEEE Standard 387-1984 whether or not this standard is a part of a plant's current licensing basis. This is not sufficiently addressed in the backfit analysis for the new rule and/or the Regulatory Guide.

2.

General - Regulatory Guide 1.108 should be extensively revised, or preferably deleted, regardless of the disposition of DG-1021.

3.

Section 1.3 - Some EDGs have a two hour rating at 110% of the continuous rating; this section should be clarified as to whether this 2 hour rating is part of the 'continuous rating'.

4.

Section 1.8 (last sentence) - Trip bypass cannot be selected in a test mode at some plants, although all trips are bypassed (except the overspeed and generator differential) in the emergency mode. Manual or automatic selection is not an option.

5.

Section 2.1 (last paragraph) - In regard to valid demands and failures:

• Declaration of inoperability should not be an automatic criterion for a valid demand and a failure. Some of the exceptions listed in 2.1 could lead to a declaration of in operability.
• A successful test following a repair or preventative maintenance should be counted as a valid demand and a successful start.
• An unsuccessful test following a repair or preventative maintenance should not be counted as a valid demand and a failure to start jf the failure was related to the repair or preventative maintenance activity; unrelated causes should be considered as valid demands and failures to start.

Comments on Proposed Revision to 1 0 CFR 50.63 and Regulatory Guide DG-1021 July 2, 1992 to CNRO-92/00055 Page 2 of 3

6.

• The above are considered necessary to keep test data current enough to be accurate and representative of the actual trend of maintenance of the diesel(s); otherwise, previous data may become outdated and mask more recent trends (see the comment below regarding Section 3.1).

Section 2.2 (first paragraph) - The last sentence (prior to 2.2.1) is not feasible to implement. Large numbers of jumpers and other nonstandard configurations are used to perform 18 month surveillances; even some six-month surveillances use recorders to monitor start times, etc. This sentence should be deleted.

7.

Section 2.2.3 - The information in parentheses implies that the use of a prelube system would be acceptable only if it is normally operating in standby, while section 2.3 (first paragraph) states that all planned tests should be preceded by a prelube period. Section 2.2.3 should be changed to specifically allow the use of a prelube system to prevent unnecessary, excessive wear or damage and to prolong diesel generator life.

8.

Section 2.3.2.4 - This section only describes the testing in section 2.2.14, while Table 1 lists the tests in 2.2.6 through 2.2.14 as 10 year tests. Section 2.3.2.4 should describe all 10 year testing as listed in Table 1.

9.

Section 2.3 & 3 - As discussed in the general comments on the proposed revision to 1 0 CFR 50.63, these requirements are redundant to the new maintenance rule and requirements/commitments from Station Blackout submittals and SERs. Further, the current industry performance in the areas of diesel generator and off-site power availability and reliability is adequate without this new rulemaking.

10.

Section 3.1 (last sentence) - A limit should be placed on the time duration for using data on both demands and starts to ensure that the data is accurate and representative of the actual trend of the maintenance of the diesel(s). A time limitation such as three or four years should provide enough data for adequate trending without relying on data which is essentially outdated.

11.

Section 3.2 (last paragraph) - The 0.007 maintenance-related unavailability number should be removed since it is not germane to the testing or trending addressed by the Regulatory Guide. If left in this document, this number might cause future interpretation problems between the NRC staff and utilities.

Comments on Proposed Revision to 10 CFR 50.63 and Regulatory Guide DG-1021 July 2, 1992 to CNRO-92/00055 Page 3 of 3

12.

Section 3.3 - The accelerated testing to recover from a 'double trigger' condition should be deleted. If a 'double trigger' is reached, then the maintenance program should be carefully inspected and proper corrective actions developed rather than immediately going to accelerated testing. Diesel generator failures should be treated the same as the failures in other safety-related components: for corrective maintenance after a failure to valid start, only a post-maintenance test should be required to identify that the root cause has been identified and corrected.

• Starting and loading the diesels are the harshest evolutions for this equipment during expected operation. As many as forty (40) extra starts might be required to return below the double trigger value. Accelerated testing is known to result in accelerated diesel wear and component aging.
• Reaching a double trigger may indicate a maintenance program deficiency.

Accelerated testing is not an appropriate nor practical method for determining the effectiveness of actions taken to correct such programmatic problems. For example, fuel oil transfer pump problems (or problems with other auxiliaries) would not be appropriately addressed by accelerated testing. Electrical or other component failures associated with aging, temperature, or design problems would also not be well addressed by accelerated testing.

• A unit may reach a double trigger due to the performance of one diesel.

However, this requirement appears to require all diesels which had experienced failures to use accelerated testing. Along these lines, the phrase "an EDG test frequency of no more than 7 days but not less than 24 hours" should be clarified concerning which of a unit's diesels should be used for accelerated testing to drop below the double triggers.

,Ut) (.;t{.I:: I NUMBER rnoPoseo RULE PR r o Cs 1 FR. I '--I 5 1<-0 (j) Nuclear GPU Nuclear Corporation One Upper Pond Road Parsippany, New Jersey 07054 201 -316-7000 The Secretary of the Commission U.S. Nuclear Regulatory Commission Washington, DC 20555 Attn: Docketing and Service Branch

Dear Sir:

TELEX 136-482 Writer's Direct Dial Number July 6, 1992 C300-92-Ll63 C320-92-Ll84

Subject:

General Public Utilities Nuclear Corporation Comments on the Proposed Revision to 10CFR50.63 "Loss of All Alternating Power" The purpose of this letter is to provide you with the GPU Nuclear comments on the following documents: I. Proposed Amendment to 1 OCFR50. 63, "Loss of A 11 Alternating Current Power".

2.

Draft Regulatory Guide DG-1021, "Selection, Design, Qualification, Testing and Reliability of Emergency Diesel Generator Units Used as Class IE Onsite Electric Power Systems at Nuclear Power Plants (Second Proposed Revision 3 to Regulatory Guide 1.9). Comments were requested via Federal Register, Vol. 57, No. 77, Tuesday, April 21, 1992. contains our responses to the four questions posed in the Federal Register Notice. provides specific comments related to the documents listed above. Where an individual comment is related to the draft regulatory guide, the regulatory guide is specifically identified. However, comments provided in Enclosure 2 should be applied to both the proposed rule and draft regulatory guide. Additionally, GPUN endorses the industry comments provided by NUMARC in their July 2, 1992 letter on the same subject. JK/EP:lga Enclosures J. Knubel Licensing & Regulatory Affairs Director JUL 16 1992 Acknowledged by card-,"---*"'*"*"-"'* GPU Nuclear Corporation is a subsidiary of General Public Utilities Corporation

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C300-92-Ll63 C32Q.,,92--Ll84 Page 2 QUESTION 1: RESPONSE 1: QUESTION 2: RESPONSE 2: QUESTION 3: RESPONSE 3: ENCLOSURE 1 GPUN RESPONSE TO QUESTIONS POSED IN THE APRIL 21, 1992 FEDERAL REGISTER NOTICE Is there a better way to identify EOG degradation than the proposed trigger values, which is practical for use by licensees, and which will improve detection of reliability degradation while minimizing false alarms? There are alternate methods to identify EOG or individual component degradation. Some of these are the use of an Engine Performance Monitoring Program, Infrared Thermography (electrical inspection) and a Vibration Monitoring Program. However, additional review would be required in order to determine the pr act i ca 1 i ty of the a 1 tern ate methods, as we 11 as their effectiveness and efficiency in detecting reliability degradation while minimizing fa 1 se a 1 arms. Is there a method which could utilize industry-wide EOG performance experience to monitor EOG reliability while providing adequate reliability degradation information for plant specific use? Utilizing industry-wide EOG performance experience to monitor the EOG reliability of a specific plant is difficult to achieve. This is due to the fact that the various p 1 ants utilize EDGs of different manufacturers and

models, installed in various configurations.

Also, the industry-wide experience includes failures that are attributable to EOGs themselves, systems or components that directly support EOG operation, as well as failures attributable to operational or procedural errors. The industry-wide data is therefore not generic. Any attempt to use this information for a specific plant must be able to account for these differences. In light of current industry EOG performance, other applicable NRC regulations and the future requirements of the maintenance rule (10CFRS0.65), is this proposed rule needed to provide continued confidence in the. reliability of EOGs and in maintaining the underlying reliability basis used for the Station Blackout rule? GPU Nuclear be l i eves that the proposed ru 1 e is not necessary. Industry performance indicates that overall EOG reliability is excellent: 98.6% for test and unplanned demands. Additionally, EOGs will be identified in the Maintenance Rule (10CFRS0.65),

C300-92-L163 C320*92--2184 Page 3 QUESTION 4: RESPONSE 4: thus ensuring management's continued attention to EDGs. Also, through the Station Blackout Rule (IODFRS0.63), licensees have docketed commitments to establish and maintain EDG target reliabilities.Tracking target reliabilities is achieved through the performance-based trigger values in the NUMARC Initiative SA which are identical to those in the rule and draft regulatory guide. Since most EDG failures are directly reportable through the licensee event report process and those that may not be reported through the LER process are brought to the site resident's attention, the NRC would be apprised of EDG failures. Finally, the basis for enforcement action may be found in the current enforcement policy. Thus, the proposed rule is duplicative and may only serve to create confusion related to a complex topic. Additionally, by requiring accelerated testing, the proposed rule will only reduce the quality of and diminish the life of EDGs. Should the proposed rule also address unavailability? GPU Nuclear believes that unavailability should not be addressed in the proposed rule since it is presently addressed in several areas such as the Technical Specifications, the Maintenance Rule and the Plant Performance Indicator Program.

C300-92-ll63 C320-92-2184 Page 4 ENCLOSURE 2 SPECIFIC GPU NUCLEAR COMMENTS ON THE PROPOSED AMENDMENT TO 10CFRS0.63 AND DRAFT REGULATORY GUIDE DG-1021

1.

Draft Regulatory Guide OG-1021 lists numerous EOG design considerations in Section 1, pages 7 through 11. It should be recognized that most plants are already designed and installed. Imposing new design considerations and requiring their implementation may require costly plant modifications and would not yield significant benefits.

2.

Accelerated testing of Emergency Diesel Generators should not be imposed by the proposed rule or regulatory guide on the basis of number of failures. EOG failures can be attributable to numerous causes which may not be indicative of prograR111atic problems. For example, a specific, associated component (e.g., relay) failure can prevent the EOG from starting. However, this isolated component can be replaced with the appropriate replacement which can be separately tested and verified to be performing properly. A subsequent successful run of the EOG after component replacement verifies the EOG is operable. Therefore, relief criteria from accelerated testing requirements should be provided prior to issuance of the rule and regulatory guide.

3.

Prior to imposing any accelerated testing requirements, disagreements on such testing between the ACRS and NRC staff, discussed in NRC letter dated May 19, 1992, Ward to Selin, should be resolved. Therein, the ACRS takes exception to accelerated testing requirements, requesting that it be changed since no benefits are expected to be derived by such testing.

4.

GPUN disagrees with the premise that maintenance related activities should be scheduled during refueling outage periods rather than during plant operation. The intent of this premise is to improve availability. During an outage, there is much ongoing concentrated work related to plant modifications, outage related maintenance and surveillance, refueling, etc. Purposely rescheduling additional EOG maintenance work which can easily be performed during p 1 ant operat i ans may only 1 engthen outages unnecessarily. Additionally, the Technical Specifications address EOG

• unavailability.

5.

A formal thirty-day report should not be required when the 3/20 trigger value is exceeded on an individual EOG. This individual EOG trigger value is a new one which has never been discussed by industry or proposed to licensees by the NRC in draft form prior to this amendment. Therefore, there is no basis for the use of the 3/20 trigger value on an individual EOG as a regulatory indicator or licensee reporting mechanism.

6.

A formal 30 day report should not be required for a 3/20 trigger value on a unit basis since the sample size of 20 demands has a high false trigger rate and is too small to draw conclusions relative to regulatory enforcement or reporting. Additionally, the 3/20 trigger value does not indicate non-compliance with IOCFRS0.63.

C300-92-Ll63 c320... 92-.us4 Page 5

7.

If notification of any single trigger exceedence is required, it should be on values consistent with NUMARC Initiative SA, which has been adopted by the industry.

8.

Draft Regulatory Guide DG-1021, page 12, section 2.1, the first sentence of the last paragraph is i neons i stent with the "Exceptions" cited in section 2. I. Specifically, the draft regulatory guide referenced section requires that each EDG failure that results in the EDG being declared inoperable shoul d be counted as one demand and one failure. There can be numerous situations in which not knowing an immediate root cause will place a licensee into a Limiting Condition for.Operation where it is later determined that a malfunction occurred which would be bypassed during an emergency EDG start. The "Exceptions" in section 2.1 would permit this as an invalid failure, yet the sentence previously referred to above would make it a valid failure with no correlatable statistical basis. As such, the first sentence of the last paragraph of DG-1021, section 2.1, page 12 should be deleted.

~~g~61r~~~~~ PR SfJ-- c s 7 FR 1L/51'-I) JUL - 6 1992 July 5, 1992 COMMENTS OF OHIO CITIZENS FOR RESPONSIBLE ENERGY, INC. ( "OCRE") ON PROPOSED RULE, "LOSS OF ALL ALTERNATING CURRENT POWER," 57 FED. REG. 14514 (APRIL 21, 1992) OCRE supports this proposed rule. As noted in the regulatory

analysis, this rule completes the regulatory scheme which was assumed when the Station Blackout rule was finalized.

Thus, this regulation is essential for the legitimacy and validity of the Station Blackout rule. The Federal Register notice also indicates that reliability of onsite emergency AC power sources is one of the main factors contributing to risk of core melt from station blackout. OCRE would also note that risk assessments, such as those in NUREG-1150, show that station blackout is a major contributor to severe accident risk; in some designs, such as the BWR/6, it is the major contributor. Therefore, it is necessary and appropriate for the NRC to establish enforceable reliability standards for emergency diesel generators. OCRE is aware that a majority of the ACRS has recommended against adoption of this rule (see ACRS letter dated May 19,

1992, re Reliability of Emergency AC Power at Nuclear Power Plants).

The ACRS recommended that the "requirement in the SBO rule for diesel reliability be interpreted as applying to populations rather than to individuals, that it be monitored on an industry-wide basis However, this ignores the fact that the Station Blackout rule was not intended to apply to populations across an entire industry, but rather to individual licensees. It is the individual licensees which must demonstrate compliance with the

rule, and against whom it is enforced by the NRC.

Thus, it is entirely proper for the NRC to establish standards for diesel generator reliability which can be enforced against specific licensees.

As ACRS members James Carroll, Ivan Catton, Carlyle Michelson, and Paul Shewmon noted in their separate comments on this

issue, "licensees with good EDG maintenance programs and root cause analysis techniques will have little difficulty in staying below any of the proposed trigger values."

It thus appears that the rule will be able to separate the innocent from the guilty (one of the ACRS majority's concerns). The NRC has identified concern over diesel generator unavailabil-1 JUL 16 ~ Acknowledged by card..., lfCISUMOWW*swuuuwMA

J.$. NIX' '. '-;,.'_i\\ ::~.JU!..ATORY COMMISSIOr. DC>:>f:Tt~J:3 & SERVICE SECTION Of.--!CE OF THE SECRETARY OF THE COMMISSION

ity due to testing and maintenance, which in practice has proved to be larger than was assumed in the development of the SBO rule. While one approach to solving this problem would be to develop more restrictive technical specifications to limit such unavail-ability, this could have the unintended consequence of discourag-ing thorough testing and maintenance. Moreover, tech spec limits on such unavailability would merely require placing the plant into shutdown if a diesel generator remains out of service beyond a certain time limit, and, as is becoming increasingly

apparent, "shutdown" does not mean "risk-free." OCRE would sug-gest that the NRC revisit the SBO rule to specifically address this issue, or, in the alternative, address it in the implementa-tion of the SBO rule, such that licensees should install addi-tional redundant onsite AC generating capacity as a

preferred response to the rule. OCRE would note this apparent typographical error in the text of the proposed rule: 10 CFR 50.63(a)(3), first sentence, which reads, "The reliability of every emergency diesel generator must be monitor by testing at least monthly." The word "monitor" should be "monitored." In conclusion, OCRE urges the NRC to adopt this proposed rule. Respectfully submitted, ~-~ Susan L. Hiatt Director, OCRE 8275 Munson Road Mentor, OH 44060- 2406 2

Southern Nuclear Operating Company Post Office Box 1295 Birmingham, Alabama 35201 Telephone 205 868-5086 DOC'<ET NUMBER PR ~ - pr,:)POSED RULE

?Y

{j) ( S' 7 F fl J '""15 1 '-1) .\\ J. D. Woodard Vice President Farley Project Docket Nos. 50-348 50-364 Mr. Samuel J. Chilk Secretary of the Commission U.S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION: Docketing and Service Branch Southern Nuclear Operating Company the southern electric system July 2, 1992 Comments on Proposed Revision to 10 CFR 50.63 "Loss of All Alternating Current Power" (57 Federal Register 14514 of April 21. 1992}

Dear Mr. Chilk:

Southern Nuclear Operating Company has reviewed the proposed Revision to 10 CFR 50.63, "Loss of All Alternating Current Power", published in the Federal Register on April 21, 1992. In accordance with the request for comments, Southern Nuclear Operating Company is in total agreement with the NUMARC comments which are being provided to the NRC. Should you have any questions, please advise. Respectfully submitted, JDW/KWW cc: Mr. S. D. Ebneter Mr. S. T. Hoffman Mr. G. F. Maxwell ~ Woodard Acknowl ed card JUL 1 6 1992 edg by -""'"""'"""""'1.t\\\\

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Georgia Power Company 40 Inverness Center Parkway Post Office Box 1295 Birmingham, Alabama 35201 Telephone 205 877 7122 C. K. McCoy DOCKET NUMBER PR 5 0 rH0?08ED RULE C~'1 Ffl l'i~l4) ,\\ Georgia Power Vice President, Nuclear Vogtle Proiect the southern etectnc system Docket Nos. 50-321 50-366 50-424 50-425 Mr. Samuel J. Chilk Secretary of the Commission U.S. Nuclear Regulatory Commission Washington, DC 20555 ATTENTION: Docketing and Service Branch July 2, JUL - 6 1992 oOCKETlNG l

~~

SERVlCE sAANCH,-..... ~ Comments on Proposed Revision to 10 CFR 50.63 "Loss of All Alternating Current Power" (57 Federal Register 14514 of April 21, 1992)

Dear Mr. Chilk:

HL-2293 ELV-03865 Georgia Power Company has reviewed the proposed Revision to 10 CFR 50.63, "Loss of All Alternating Current Power", published in the Federal Register on April 21, 1992. In accordance with the request for comments, Georgia Power Company is in total agreement with the NUMARC comments which are being provided to the NRC. Should you have any questions, please advise. Respectfully submitted, CKM/KWW ,'Ul. l 6 1992 Acknowledged by card "-'""""'"m".. lft"-..

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Mr. Samuel J. Chilk U.S. Nuclear Regulatory Commission Page 2 cc: Georgia Power Company Mr. J. T. Beckham, Jr., Vice President, Plant Hatch Mr. W. B. Shipman, General Manager - Plant Vogtle Mr. H. L. Sumner, Jr., General Manager - Plant Hatch NORMS U. S. Nuclear Regulatory Commission, Washington, DC Mr. K. N. Jabbour, Licensing Project Manager - Hatch Mr. D. S. Hood, Licensing Project Manager - Vogtle U. S. Nuclear Regulatory Commission, Region II Mr. S. D. Ebneter, Regional Administrator Mr. L. D. Wert, Senior Resident Inspector - Hatch Mr. B. R. Bonser, Senior Resident Inspector - Vogtle

DOCKET NUMBERPI 07:: PROPOSED RULE (_r;7 f rt /'-/SIL/ [ii] Tennessee Valley Authority, 1101 Market Street, Chattanooga, Tennessee 37402 July 1, 1992 The Secretary of the Commission U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Attn: Docketing and Service Branch ! ULKL 1 Lr) USNHC

• 92 JUL -6 Ail :12 EMD-PS OWNERS GROUP RESPONSE TO PROPOSED RULE FOR STATION BLACKOUT AND EDG RELIABILITY

Dear Sirs:

Enclosed are the comments (Attachment A) from the Electro-Motive Power Systems Diesel Generator (EMD-PS) Owners Group regarding the proposed amendment to 10 CFR 50.63, Station Blackout and Regulatory Guide DG-1021, EDG Reliability. The comments provided express the concerns of over 20 nuclear utilities (Attachment B) with years of good diesel generator operating history. Should you have questions, please direct them to me at (615) 751-8205. Very truly yours, , Chairperson EMD-PS Owners Group Tennessee Valley Authority Enclosure cc: NUMARC 2584Q Owners Group Representatives Duke Engineering and Service JUL 16 1992 Acknowledged by card........... --....... -... -

U.S. NUCl !== ~r> ~EGULATORY COMMISSIOit OOCKt: T!~G & SEFNICE GECTION Ofr,('E OF TH£: SECRET ARY eF TnE: COMMISSIOii Document Statistics Pcstmarl< Date 7/:1-l q 2-. Cor-es Received __ / ______ _ Add'I Copies Reprocm,d..,..J ___ _ Special~ /iX hs;, p () tlJ 'tL Lr; {~ l 2.,

ATTACHMENT A EMO-POWER SYSTEMS OWNERS GROUP RESPONSE TO NRC'S REQUEST FOR COMMENTS ON THE PROPOSED RULE FOR STATION BLACKOUT AND EMERGENCY DIESEL RELIABILITY The Electro-Motive Division of GM has produced medium speed diesels for nuclear and non-nuclear applications. These engines have a proven history of reliable service. Within the past few years 21 utilities have joined efforts as the EMD-PS Owners Group for the purpose of sharing information and experience related to Emergency Diesel Generator operation. The following discussion is a response to NRC's request for comments on the proposed amendment to 10 CFR 50.63. These comments are offered consistent with and in addition to individual member utility comments. BACKGROUND The proposed Rule 10 CFR 50.63 and Regulatory Guide 1.9, Revision 3 are results of discussions and negotiations regarding Emergency Diesel Generator (EDG) reliability that began with the Station Blackout (SBO) Issue. The SBO Issue noted that EDG reliability was a large contributor to core melt probability and the industry committed to improve this reliability via a plan to be developed through Generic Issue B-56. A NUMARC group and an NRC group worked on this issue concurrently with the goal to develop a reliability plan that could be adopted by both groups. The result was that two plans were developed simultaneously; one is the recently published Appendix D to NUMARC 87-00 describing industry's position on EDG reliability and the second is the draft regulatory guide. To accomplish the goal, it was the intent from industry that the regulatory guide would reference and incorporate the contents of Appendix D; however, this was not accomplished. Much effort went into discussions between NUMARC and the NRC on how reliability could be improved (especially in light of the recent industry figures that already places reliability at 98%+). At the heart of the discussion was the issue of accelerated testing, which industry believes and NRC studies (NUREG 4590) confirm is one of the leading causes of unreliability. SPECIFIC COMMENTS The issuance of the regulatory guide as a rule is not warranted. Development and use of a reliability program using the NUMARC 87-00, Appendix D document as guidance and elimination of accelerated

testing will improve or maintain current reliability. Significant improvement of reliability of EDG' s beyond the 98%+ currently being experienced is an unrealistic expectation. We believe that development of reliability programs using the NUMARC document as guidance with the elimination of accelerated testing is a much more effective means of improving reliability than the issuance of fines on a daily basis until a specified number of successful starts is reached. Much of the intent of this rule is duplicated by the Maintenance Rule. In addition, in order to meet certain requirements of the proposed guide, it is extremely possible that some utilities will have to install a "swing" diesel that may cost anywhere from $2Q million to $100 million depending on the site-specific circumstances and license requirements. This clearly exceeds the scope of the current backfit analysis. There is redundancy and overlap with the proposed 3 in 20 failure reporting requirement and the 4 in 25 "problem diesel" requirement. It is recommended that 3 in 20 be used as an early warning indication only with no reporting requirement. Twenty demands represents too small a sample size to be statistically meaningful for use a s anything but an early warning mechanism. The corrective action for the 4 in 25 "problem diesel" should include the necessary number of tests to ensure the problem is resolved. No specific number of tests should be identified. The problem diesel trigger could then be accepted as proposed. In addition, this group believes reporting each diesel failure as is currently the practice via writing an LER serves no useful purpose. The Owners Group recommends to delete the requirement to report each failure and require a report upon exceedence of the 4 in 25, 5 in 50, and 8 in 100 triggers. This position meets the intent of providing a reasonable amount of information when it is needed. This is especially true as related to the requirement to notify NRC within 4 hours from the time of the most recent valid failure. Determination of whether a failure is valid or invalid can be an intricate process involving days as opposed to hours. The statement should be corrected to say that notification is required 4 hours after the determination that a failure is valid and a double trigger exceedence exists. This will prevent many notifications that would be made in error. The regulatory consequences for exceedence of the double trigger are too severe. Imposing a Severity Level III violation and potential fines for each day that a unit is outside the double trigger exceedence will be a signal to promote fast action, not quality action. This proposed means of regulation should be deleted. As previously noted, accelerated testing of the EDGs has been shown to be of more harm than good as the constant testing, in some cases every 3 days for 2 years, has actually added to the overall unreliability of the machines. The proposed guide requires accelerated testing upon exceedence of a double trigger and problem 2

diesel trigger. This is in direct conflict with the purpose of increasing reliability. This form of testing based upon exceedence should be deleted. In lieu of this testing, the Owners Group recommends the actions specified in NUMARC's 87-00, Appendix Das the appropriate action for recovery from a double trigger exceedence. The last paragraph of Section 2.1 should be clarified such that the post maintenance test to declare the EDG operable does count if successful. If not successful, the test would not count and further troubleshooting would be pursued. Equipment unavailability is addressed by the Maintenance Rule and the use of the INPO industry-wide Plant Performance Indicator Program. Therefore, unavailability should not be addressed in the proposed rule again. Reliability and unavailability are competing goals and the NRC should not promote reduction of prudent maintenance activities to increase availability at the expense of reliability. As ~n example, the proposed rule indicates that the NRC assumed that EDG availability exceeds 99.3% as a part of the res olution to SBO. The proposed rule further assumes that this availability level will be achieved during power operation and during refueling outages. The latter is a drastic change from current practice. The ability to perform maintenance on EDGs especially during outages is necessary. High reliability in EDGs is only partially achieved through condition monitoring. On a per nuclear unit basis, an unavailability level of 0.007 equates to about 61 hours per year that a nuclear unit's diesels may be out of service.The current industry median of unavailability is 0.017. Therefore, the 0.007 is grossly insufficient and will result in degraded reliability. Table 1 allows tests 2.2.6 through 2.2.13 to be performed every 10 years. Currently these tests are performed every refueling outage. This is a positive aspect of the guide. However, some of these tests should be performed whenever a significant adjustment is made to the generator excitation or governor subsystems. In addition, the guide should incorporate enhancements to testing allowed by Generic Letter 84-15 that permit slow starting of the engine and eliminating many of the detrimental effects of fast starting. The guide should also address and permit the use of simulated testing in lieu of actual testing of the engine. This is especially important for certain systems such as controls. Furthermore, the guide should specify the conditions required to restart on the hot start test as well. 3

EMD-PS OWNERS GROUP MEMBERSHIP Florida Power & Light Connecticut Yankee Atomic Power Washington Public Power Supply GPU Nuclear Gulf States Utilities Entergy Operations, Inc. New York Power Authority Commonwealth Edison Tennessee Valley Authority Wi~consin Public Service Carolina Power & Light Duke Power Niagara Mohawk Power Maine Yankee Atomic Wisconsin Electric Virginia Power Centeroir Energy Illinois Power Southern California Edison Northern States Power Portland General Elettric ATTACHMENT B

~ DUKE ENGINEERING , OC~ET,!JUMBER , D

• . 0Sc.:D RULE

~ & SERVICES, INC. C ~7 F /t I q_,.;.,...... 5,~c,~ r;- DocKnrn USNHC 230 South Tryon St P.O. Box 1004 Charlotte, NC 28201-1004 July 1, 1992 The Secretary of the Commission U.S. Nuc l ear Regulatory Commission Washington, DC 20555 ATTN: Docketing and Service Branch

• 92 JUL -6 P 3 :07

Subject:

Cooper-Enterpri se Clearinghouse Response to Proposed Rule for Station Blackout and EDG Reliability MTS-4086

Dear Sirs:

Bus (704) 373-2473 Fax (704) 373-2695 Enclosed are the comments from the Cooper-Enterprise Clearinghouse regarding the proposed rule for station blackout and EDG reliability, Regulatory Guide DG-1021. The comments provided express the concerns of 9 nuclear utilities with years of good diesel generator operating history. Should you have questions, please direct them to R.J. (704) 875-4065. (Rick) Deese at

---

.~. George Chairperson Cooper-Enterprise Clearinghouse TU Electric

~/ttn~x~ t Manager Enclosure xc: NUMARC Clearinghouse Representatives Cooper-Enterprise Clearinghouse Duke Engineering & Services, Inc. JUl 16 ~~, Acknowledged by card""""'""""'"""~""" . I

1 (' ' t

COOPER-ENTERPRISE CLEARINGHOUSE RESPONSE TO NRC'S REQUEST FOR COMMENTS ON THE PROPOSED RULE 50.63 FOR STATION BLACKOUT AND EMERGENCY DIESEL RELIABILITY Cooper-Enterprise currently supports medium speed diesels for nuclear and non-nuclear applications. These engines have a proven history of reliable service. In 1984, 13 utilities joined efforts as the TDI Owners Group for the purpose of addressing problems common to these engines. In 1985, this group became the current Cooper-Enterprise Clearinghouse with the intent and goal of sharing information and experience related to Emergency Diesel Generator operation. The following discussion is a response to NRC's request for comments on the proposed amendment to 10 CFR 50.63. These comments are offered consistent with and in addition to individual member utility comments. BACKGROUND The proposed Rule 10 CFR 50. 63 and draft Regulatory Guide 1. 9, Revision 3 are results of discussions and negotiations regarding Emergency Diesel Generator (EDG) reliability that began with the Station Blackout (SBO) Issue. The SBO Issue noted that EDG reliability was a large contributor to core melt probability and the industry committed to improve this reliability via a plan to be developed through Generic Issue B-56. A NUMARC group and an NRC group worked on this issue concurrently with.the goal to develop a reliability plan that could be adopted by both groups. The result was that two plans were developed simultaneously; one i s the recently published Appendix D to NUMARC 87-00 describing industry's position on EDG reliability and the second is the draft regulatory guide. To accomplish the goal, it was the intent from industry that the regulatory guide would reference and incorporate the contents of Appendix D; however, this was not accomplished. Much effort went into discussions between NUMARC and the NRC on how reliability could be improved (especially in light of the recent industry figures that already places reliability at 98%+). At the heart of the discussion was the issue of accelerated testing, which industry believes and NRC studies (NUREG 4590) confirm is one of the leading causes of unreliability. SPECIFIC COMMENTS The issuance of the regulatory guide as a rule is not warranted. Development and use of a reliability program using the NUMARC 87-00, Appendix D document as guidance and elimination of accelerated testing will improve or maintain current reliability. Significant improvement of reliability of EDG's beyond the 98%+ currently being experienced is an unrealistic expectation. We believe that

development of r eliability programs using the NUMARC document as guidance with the elimination of accelerated testing is a much more effective means of improving reliability than the issuance of fines on a daily basis until a specified number of successful starts is reached. Much of the intent of this rule is duplicated by the Maintenance Rule.. In addition, in order to meet certain requirements of the proposed guide, it is extremely possible that some utilities will have to install a "swing" diesel that may cost anywhere from $20 million to $100 million depending on the site-specific circumstances and license requirements. This clearly exceeds the scope of the current backfit analysis. There is redundancy and overlap with the proposed 3 in 20 failure reporting requirement and the 4 in 25 "problem diesel " requirement. It is recommended that 3 in 20 be used as an early warning indication only with no reporting requirement. Twenty demands represents too small a sample size to be statistically meaningful for use as anything but an early warning mechanism. The corrective action for the 4 in 25 "problem diesel " should include the necessary number of tests to ensure the problem is resolved. No specific number of tests should be identified. The problem diesel trigger could then be accepted as proposed. In addition, this group believes reporting each diesel failure as is currently the practice via writing an LER serves no useful purpose. The Clearinghouse recommends to delete the requirement to report each failure and require a report upon exceedence of the 4 in 25, 5 in 50, and 8 in 100 triggers. This position meets the intent of providing a reasonable amount of information when it is needed. This is especially true as related to the requirement to notify NRC within 4 hours from the time of the most recent valid failure. Determination of whether a failure is valid or invalid can be an intricate process involving days as opposed to hours.

• The statement should be corrected to say that notification is required 4 hours after the determination that a failure is valid and a double trigger exceedence exists.

This will prevent many notifications that would be made in error. The regulatory consequences for exceedence of the double trigger are too severe. Imposing a Severity Level III violation and potential fines for each day that a unit is outside the double trigger exceedence will be a signal to promote fast action, not quality action. This proposed means of regulation should be deleted. As previously noted, accelerated testing of the EDGs has been shown to be of more harm than good as the constant testing, in some cases every 3 days for 2 years, has actually added to the overall unreliability of the machines. The proposed guide requires accelerated testing upon exceedence of a double trigger and problem diesel trigger. This is in direct conflict with the purpose of increasing reliability. This form of testing upon exceedence should be deleted. In lieu of this testing, the Clearinghouse recommends the actions specified in NUMARC's 87-00, Appendix Das 2

the appropriate action for recovery from a double trigger exceedence. The last paragraph of Section 2.1 should be clarified such that the post maintenance test to declare the EDG operable does count if successful. If not successful, the test would not count and further troubleshooting would be pursued. Equipment unavailability is addressed by the Maintenance Rule and the use of the INPO industry-wide Plant Performance Indicator Program. Therefore, unavailability should not be addressed in the proposed rule again. Reliability and unavailability are competing goals and the NRC should not promote reduction of prudent maintenance activities to increase availability at the expense of reliability. As an example, the proposed rule indicates that the NRC assumed that EDG availability exceeds 99.3% as a part of the resolution to SBO. The proposed rule further assumes* that this availability level will be achieved during power operation and during refueling outages. The latter is a drastic change from current practice. The ability to perform maintenance on EDGs especially during outages is necessary. High reliability in EDGs is only partially achieved through condition monitoring. On a per nuclear unit basis, an unavailability level of 0.007 equates to about 61 hours per year that a nuclear unit's diesels may be out of service. The current industry median of unavailability is 0.017. Therefore, the 0.007 is grossly insufficient and will result in degraded reliability. Table 1 allows tests 2.2.6 through 2.2.13 to be performed every 10 years. Currently these tests are performed every refueling outage. This is a positive aspect of the guide. However, some of these tests should be performed whenever a significant adjustment is made to the generator excitation or governor subsystems. In addition, the guide should incorporate enhancements to testing allowed by Generic Letter 84-15 that permit slow starting of the engine and eliminating many of the detrimental effects of fast starting. The guide should also address and permit the use of simulated testing in lieu of actual testing of the engine. This is especially important for certain systems such as controls. Furthe*rmore, the guide should specify the conditions required to restart on the hot start test as well. 3

O"OCKET NUMBER Pl PROPOSED RULE 5 0 (57Ffl/1/S!'-/) DOCKETED GE Nuclear Energy (' General Electric Company June 30, 1992 The Secretary of the Commission U.S. Nuclear Regulatory Commission Washington, DC 20555 ATTN: 9 Gentlemen: Docketing and Service Branch 175 Curtner Avenue, San Jose, CA 95125

• 92 JUL -6 Al I :21

.:in 1c~: OF.'3[CR1-'j,q,*,1 G!;CKC-1 :/iG ', '*~hV!(:f S!\\l~ NCI~ MFN No. 140-92 General Electric herein submits comments [see Attachment] on the Draft Regulatory Guide DG-1021 (second proposed revision 3 to Regulatory Guide 1.9) and proposed rule RIN 3150-AE06. We find that the positions stated in the proposed revision to the Regulatory Guide are inconsistent with the previous industry and Staff positions regarding the demonstration of reliability of emergency AC power sources as well as inconsistent with current and proposed Technical Specifications. Should you have any questions regarding our comments please do not he~itate to contact Mr. Noel Shirley of my staff on 408-925-1192 at your earliest convemence. Sincerely, ~~ Safety, Environmental, and Quality Assurance cc: L.S. Gifford (GE) A. Marion (NUMARC) MFN file JUL 1s -~ Acknowledged by card"'""'""""*""""""'"'

U.S. NlJCLr Ml HiGU:.A.iORY CO~MiSSiO~ DOCK;;Ttr!G a Sl:AVICE SECT,ON Or-FICE OFlHl SECR::TARY ci: THE COMM:SSION Docur,,ent S'3tietics Pc*stmark Date _7_/J_JC/ ____ ?-___ _ Copies Aecei~d ___ ____ _ Add'I Copies Repr()ljuced _.3 __,--_ _ Special Ois.;tlltian_.../2......,X.....,Q.....,\\.,...,..... f.-n_c;,.,,.,-- ..R. tr

bee: W.P. Sullivan (GE) P.O. Knecht (GE) K.W. McCausland (GE) B.P. Grim (GE) P.N. Pathak (GE) R.C. Patel (GE) R.T. Kem (GE)

ATTACHMENT The NRC requested in their proposed rule {RIN 3150-AE06} four areas in which specific industry comments would be helpful. GE will attempt to respond to each of those areas. We will also provide comments on the apparent inconsistencies between this proposed revision and existing NRC approved documents.

1.

Is there a better way to identify EOG degradation than the proposed trigger values? Comment 1 We think that there is a better way to approach the measuring of potential degradation of the EOG's. The Vendor shop data [per IEEE-387], along with the pre-op/startup test data provides a larger reliability base than just that data collected during the previous 20/50/100 tests plus 69 pre-op starts. Industry based history data per manufacturers size, model number proposed in Comment 2 are also a better method of tracking the potential for degradation. We suggest that this data, using the Regulatory Guide's approach to counting failures to show a deviation or variance from the data base, is a better way to identify potential degradation. Taking credit for this data base, at least up through any major modifications performed on the EOG's, would allow more appropriate actions to be taken to increase test frequency or reporting based on the R.G. requirements. Excessive testing of OG's will degrade the engine and may effect availability. We therefore are unable to understand the logic of adding the concept of full system testing. It would appear more meaningfull to identify the most troublesome components and processes and to monitor their degradation without excercising the entire machine.

2.

Is there a better method which could utilize industry-wide EOG performance histroy to provide adequate reliability information for plant specific use? Comment 2 We feel that it is possible for industry (INPO/EPRI/NUMARC/Owners Groups) and the NRC to work together to develop a "Best" method based on the Industry History as a function of EOG manufacturer, size, plant load, etc.

3.

In light of the recent industry performance and the future requirements of the maintenance rule {10CFRS0.63}, is this proposed rule necessary? Comment 3 No, based on the current industry positions stated in IEEE-383 and IEEE-747 and ASME [ANSI] OM-16, there is sufficient basis to justify the deletion of this proposed rule.

4.

Should this proposed rule also address EOG unavailability? Comment 4 The issue of unavailability should not be addressed as a number but only as part of an integrated EOG total performance improvement program. The unavailability can also be tracked as a part of industry experience data proposed in Comment 2. This is also reported per R.G. 1.108, Position 3b. It would appear that looking at both would creat a situation of 'double-dimensioning'.

Other Comments

1.

10CFR50.63/R.G. 1.9, Rev. 3 Changes with respect to R.G. 1.108 and Technical Specifications R.G. 1.108/Standard Technical Specifications have a decreasing schedule of test frequency--from 31 days for 1 failure per 100 tests down to 3 days for 4 or more failures up to 7 failures total [it is noted that the Standard Technical Specifications (STS) contain a reference to R.G. 1.108]. Late plants have dual failure schedules [1 per 20 tests or 4 per 100 tests for 31 days plus 2 per 20 or 5 per 100 test frequency--an unnecessary increase in test frequency and an increase in permissible failure per demmand [it is noted that this also includes a reference to R.G. 1.108]. The Improved Technical Specifications use intermediate tests with the same test frequency--3 per 25 tests for 31 days plus 4 per 25 tests for 7 days [again they include a reference to R.G. 1.108]. The proposed 10CFR50.63/R.G. 1.9 Rev. 3 adds 4 failures out of 25 demands per EOG with a decreased testing period of no less than 24 hours and no more than 7 days with the reporting of failures contained in the last 20, 50, and 100 demands [per 10CFR50.63 (a)(3)(i)(A)]. This conflicts with the Standard Technical Specification/R.G. 1.108 regarding minimum test frequency. It also conflicts with the supplemental report at 4 starts rather than 7 out of 100 tests (STS) It appears that the NRC is mixing the existing availabilty design base {Technical Specifications and Reguatory Guide}. The existing design basis for availability is considered adequate. If the NRC wants or requires an added reliability testing program involving the establishment of minimum testing that should be separate from the Technical Specification requirements. We do not see the need for Technical Specification changes for in-service operability testing.

WIiiiam H. Rasln Vice President & Director Technical Division NUCLEAR MANAGEMENT AND RESOURCES COUNCIL DOCKETED USNRC 1776 Eye Street, N.W.

• Suite 300
• Washington, DC 20006-~j JUL _2 p J :04 (202) 872-1280 July 2, 1992 r r-C."fr !:",,-

... rr...., T"- r L~ '. '~....,., Mr. Samuel J. Chilk Secretary of the Commission U.S. Nuclear Regulatory Commission Washington, DC 20555

SUBJECT:

Nuclear Industry Comments on the Proposed Amendment to 10 CFR § 50.63, "Loss of All Alternating Current Power," 57 Fed. Reg. 14514, April 21, 1992

Dear Mr. Chilk:

The enclosed comments on the subject proposed amendment to the station blackout rule are submitted on behalf of the nuclear industry by the Nuclear Management and Resources Council, Inc. (NUMARC) 1

• We appreciate the opportunity to provide industry comments and trust this input is constructive and beneficial to NRC's consideration of the proposed amendment.

The comments are provided in four separate enclosures. Enclosure 1 contains responses to the four questions posed in the Federal Register notice. includes specific comments on the proposed amendment and Draft Regulatory Guide DG-1021. Enclosure 3 provides comments on the AEOD Special Study Report AEOD/S91-01 that is referenced in the Federal Register notice. Enclosure 4 contains comments on the application of a performance based regulatory approach to the proposed amendment. It is our understanding that the rationale for the proposed amendment, according to the Staff Requirements Memorandum (SRM) dated June 26, 1991, was the need to secure enforceable commitments from licensees to address Generic Safety Issue B-56 and to establish a firm legal basis for regulatory action. Additionally, the Commission's desire to employ a performance-based regulatory approach vs. programmatic regulation also gave impetus to the proposed amendment. We agree with the Commission stipulating the rulemaking process as opposed to the use of a generic letter and the provisions of 10 CFR 50.54(f) as the means of promulgating regulatory requirements. We also strongly support NRC efforts to employ a performance-based regulatory philosophy to new 1NUMARC is the organization of the nuclear power industry that is responsible for coordinating the combined efforts of all utili ties li censed by the NRC to construct or operate nuclear power plants, and of other nuclear industry organizations, in all matters involving generic regul atory poli'cy issues and on the regulatory aspects of generic operational and technical issues affecting the nuclear power industry. Every utili ty responsible for constructing or operating a nuclear power plant in t he ~nited States is a member of NUMARC. In addition, NUMARC's members incl ude major architect/engineering firms and all of the major nuclear steam supply system vendors. JUL 15 199Z ,'cknowledged by card.......... "~..... "... -.. :;; 0

U.S. NllCLt::AR RF.:GU!..ATORY COHMISSIOi\\ DOC!{E:Tl~G & SERVICE SE:,TION OFhCE OF T!-lf: SEC~ETAfft' (lF THE c.ur.;M,SCION Oocurnei!t S:aosties Pr.s!mar:< Date /::f:M-hpl_ k, ) l 11 e,u-e_J,, Co?es Aeoeived_..__ _____ _ ~*, Copit, Rtptoduced _J _____ _ ~ llStibulOn g 1:.c 01, f-J arz., ~ fi<..r--/<-,--z 5

Mr. Samuel J. Chilk July 2, 1992 Page 2 regulation as well as to the revision of existing regulatory requirements, where appropriate. However, notwithstanding our agreement with and support of these actions, NUMARC believes the proposed amendment to 10 CFR § 50.63 is *not needed. To briefly summarize, our belief that the proposed amendment is not needed is based on the following:

1.

The intended goal of Generic Safety Issue B-56 was to achieve 0.95 EOG reliability across the industry. Since 1983, the industry average EOG reliability has been above 0.98. The industry is uniformly monitoring and maintaining EOG reliability through NUMARC Initiative 5A, which has been implemented by all nuclear utilities. Thus, we believe B-56 has been resolved by industry performance and the mechanisms are in place to sustain that performance.

2.

NRC already has sufficient legal basis to take regulatory action to address EOG reliability. In addition to the docketed commitment made by licensees to the 0.95 or 0.975 target reliabilities in their station blackout rule responses, existing regulations such as Criterion XVI of Appendix B provide a separate enforcement basis. In Enclosure 2, we cite an example where such enforcement action was taken before any single trigger was exceeded. Thus, the rationale for the proposed amendment citing the need for enforcement basis is invalid and not consistent with current enforcement practices.

3.

The promulgation of the maintenance rule, 10 CFR § 50.65, obviates the need to employ a performance-based regulatory approach through the proposed amendment. The implementation of the maintenance rule will establish performance goals and ensure management attention to important systems and components, as appropriate. Thus, the proposed amendment would be duplicative of this intent. Additional detail and bases that support our belief that the proposed amendment is not needed are provided in the enclosures. We are also compelled to comment on the subject of EOG accelerated testing. We continue to hold the position that any form of accelerated testing is detrimental to safety. We are extremely disappointed with the lack of progress on regulatory relief from the current accelerated testing requirements. Since the Spring of 1990, there has been agreement between the NRC staff and industry on the 4/25 criteria for an individual EOG as the threshold for conducting seven consecutive accelerated tests. This criteria has already been incorporated into the improved standard technical specifications. Further, the staff was directed to address industry's request for relief in the June 26, 1991, SRM by October 15, 1991. Generic guidance for revising technical specifications to the 4/25 criteria has been under

Mr. Samuel J. Chilk July 2, 1992 Page 3 development by NRC since that time. In the meantime, EDGs continue to be subjected to the current accelerated testing requirements, which reduce the long-term reliability and design life of these machines. Additionally, the proposed amendment calls for an unprecedented level of accelerated testing following exceedence of the double trigger values, which would further degrade these machines. We believe a threshold has long been surpassed when the need for regulatory assurance results in activities detrimental to safety. We implore NRC to expeditiously grant relief to the agreed upon criteria for accelerated testing of individual EDGs. NUMARC would welcome the opportunity to meet with NRC management to discuss industry comments on the proposed amendment. Once again, we appreciate the opportunity to provide comments on this important subject. WHR/ARP/cma Enclosures Sincerely, \\.

//

-Aj ~ 11/AU-t~----~ William H. Ras in

ENCLOSURE 1 INDUSTRY COMMENTS ON THE PROPOSED REVISION TO 10 CFR § 50.63 The following are responses to the four questions raised in the April 21, 1992, Federal Register notice: QUESTION 1: Is there a better way to identify EOG degradation than the proposed trigger values, which is practical for use by licensees, and which will improve detection of reliability degradation while minimizing false alarms?

RESPONSE

NUMARC believes that the trigger values identified in revision 1 of NUMARC 87-00, Appendix 0, and implemented by the industry through NUMARC Initiative SA, are the most practical and effective means of monitoring EOG reliability on a nuclear unit basis. While we acknowledge the views of the ACRS on this subject and recognize that other techniques may also provide a means of monitoring EOG reliability, we strongly assert that the trigger values encompass a graded approach that holds false alarms at a reasonable level and provides an indication of declining reliability. In addition, based on a survey of the industry conducted by NUMARC earlier this year, all nuclear utilities have implemented Initiative SA using the trigger values to monitor their unit EOG reliability. Thus, we believe that any changes to these trigger values at this point would be counterproductive and would only serve to obfuscate a focused and practical approach that is already in place. QUESTION 2: Is there a method which could utilize industrywide EOG performance experience to monitor EOG reliability, while providing adequate reliability degradation information for plant specific use?

RESPONSE

Industrywide EOG reliability data includes data on the successes and failures to start and load-run a variety of EOGs of different manufacturers and models. In addition, the data includes failures that are attributable to systems or components that directly support EOG operation, and also includes failures attributable to operational or procedural errors. In short, the industrywide data is not generic. Any attempt to use industrywide data to provide adequate reliability information for plant specific use must be able to account for a myriad of plant specific differences. Additionally, we do not believe there is any methodology that would substitute for effective root cause analyses and appropriate corrective actions to address individual EOG failures. These actions provide the foundation for the graded approach to maintaining EOG reliability. 1

QUESTION 3: In light of current industry EOG performance, other applicable NRC regulations and the future requirements of the maintenance rule (10 CFR § 50.65), is this proposed rule needed to provide continued confidence in the reliability of EOGs and in maintaining the underlying reliability basis used for the Station Blackout rule?

RESPONSE

NUMARC believes that the proposed rule is unnecessary. The original intent of Generic Issue B-56 was to achieve 0.95 EOG reliability. Since 1983, data compiled by EPRI and through the industrywide plant performance indicator program have established that the industry average EOG reliability has been above 0.98. This level of performance has been acknowledged and accepted by the NRC and Advisory Committee for Reactor Safeguards (ACRS). Thus, we believe industry EOG performance alone is sufficient for closure of B-56 and certainly questions the need for the proposed rule. There are several existing regulatory requirements that also obviate the need for the proposed rule. EOGs will certainly be identified as risk significant components under the maintenance rule. The implementation of the maintenance rule will ensure management's continued attention to EOGs and will correct any degradation of performance. The proposed revision to the station blackout rule would be duplicative both in intent and practice, and would create unintended confusion. Other existing regulatory requirements also pertain to EOGs. Licensees have docketed convnitments to the target reliabilities per their Station Blackout rule responses. Industry has reaffirmed that with this commitment comes the understanding that the chosen target reliability will be monitored and maintained. Individual EOG failures are reported through the LER process. Moreover, the current enforcement policy has sufficient bases to ensure regulatory compliance. Furthermore, we note that in the Federal Register notice under "Need for the Proposed Amendment," one of the reasons given for this revision is"... to provide a basis for taking regulatory action when there is reasonable evidence from surveillance testing that EOG re 1 i ability degraded be 1 ow se 1 ected target 1 eve 1 s." Subsequently, under the section on "Enforcement Considerations," Criterion XVI of Appendix Bis cited as a basis for regulatory action. In a recent case a licensee was issued a $50,000 civil penalty, based on the above criterion, for two separate failures on different EOGs that were seven months apart. ~ of the trigger values had been exceeded and the reliability was above 0.98. While we express no opinion about the reasonableness of the imposition of this civil penalty, we point to it as an example of the currently available means of enforcement. To cite the need for a separate enforcement basis as a rationale for the proposed rule is inconsistent with current NRC practices in implementing the existing enforcement policy. 2

We firmly believe that industry actions will continue to provide confidence in sustaining the high level of EDG reliability and will maintain the underlying reliability basis used for the Station Blackout rule. As stated previously, all utilities have implemented the trigger values under NUMARC Initiative SA. In addition, both EDG reliability and unavailability data is compiled and evaluated through the industrywide plant performance indicator program. Thus, industry has the mechanisms in place to ensure that EOGs will continue to receive a high level of visibility and management attention. QUESTION 4: Should the proposed rule also address unavailability?

RESPONSE

No, the proposed rule should not address unavailability. Unavailability is already addressed in several other areas, including the maintenance rule, technical specifications, and the industrywide plant performance indicator program. Thus, inclusion of unavailability in the proposed rule would only be duplicative of existing regulations and industry programs. 3

ENCLOSURE 2 SPECIFIC COMMENTS ON THE PROPOSED RULE AND REGULATORY GUIDE The following are specific comments on the proposed rule and regulatory guide. Convnents provided on the proposed rule should also be applied to the applicable sections of the regulatory guide. While we believe that the proposed rule is unnecessary, these comments are offered for consideration and would apply to any proposed regulatory actions regarding EDG reliability.

1.

"Reporting" or "Earlv Warning" Trigger Values - the proposed rule requires reporting when the 3/20 trigger is exceeded on either an individual or nuclear unit basis. We disagree with the proposed requirement on an individual EDG basis. A sample size of 20 demands is too small to draw conclusions about degrading reliability or otherwise infer statistically valid judgements. In addition, this provision is inconsistent with the trigger values implemented through NUMARC Initiative SA. Utilities are currently monitoring individual EDG performance against the 4/25 trigger value for accelerated testing only. Thus, the added 3/20 trigger value on an individual EDG for reporting purposes offers no meaningful insights relative to chosen target reliabilities. With regard to reporting/early warning trigger values on a unit basis, a viable alternative to the 3/20 value of the proposed rule would be to report on any single trigger exceedance, i.e., 3/20 or 5/50 or 8/100 for the 0.95 target reliability, and 3/20 or 4/50 or 5/100 for the 0.975 target reliability. Not only would this be more consistent with the guidance contained in NUMARC 87-00, Appendix D, but it provides the NRC information germane to the overall performance of the mix of EDGs assigned to nuclear power plant unit which is consistent with the basis of the target reliability.

2.

Enforcement Considerations - we disagree with the application of enforcement action as described in the proposed rule. Equating exceedance of the double trigger values to Severity Level III violations is inappropriate in that it eliminates any consideration of plant specific actions taken by licensees in response to EDG failures. This appears contrary to the current enforcement policy that considers all relevant factors, i.e., root cause, corrective action, etc. It disregards the fundamental issue of safety significance that must be an integral part of any consideration for enforcement action. We also believe that revision to the current enforcement policy is unnecessary in that sufficient bases for regulatory action already exist, e.g., Appendix B, Criterion XVI. In addition, it is an unavoidable fact that the occurrence of EDG failures is in part governed by statistical uncertainty. A plant will occasionally exceed the double triggers for no other reason than chance, even though the underlying reliability of its EDGs is above the target reliability. For example, a plant that has a selected 95% target 1

reliability, and actual underlying EOG reliability is a point above this (96%), has a 44% chance of having a statistically induced false double trigger exceedance within 10 years. A plant that has a 97.5% target reliability, and actual underlying reliability of 98%, has a 32% chance of having a statistically induced false double trigger exceedance within 10 years. The trigger values were developed to be part of a performance based, graded approach to EOG performance. This approach emphasizes the importance of root cause and effective corrective action in response to individual failures of EDGs. This is the fundamental element of industry's approach to maintaining EOG reliability. The trigger values were not intended and should not be used as the sole basis for punitive actions. The sample sizes are insufficient to conclude whether exceeding a double trigger is statistically induced or indicative of a genuine underlying problem. A consequence of the proposed policy could be an increase in EOG unavailability. With so much regulatory emphasis placed on not exceeding the double triggers, the incentive to perform every conceivable preventive maintenance task in order to preclude potential failures would be signi ficant. The punitive nature of the proposed actions is also inconsistent with the graded approach to declining reliability as encompassed by the trigger values. These triggers were developed not as right or wrong/pass or fail criteria, but rather as a means of initiating reasonable and appropriate remedial actions to address failures. One of the tenets of a performance based regulatory philosophy is to allow a better allocation of both licensee and NRC resources where performance suggests increased attention is warranted. A more constructive way to approach enforcement that is consistent with this philosophy would be a focused inspection following exceedance of the double trigger values. This would allow NRC the opportunity to evaluate in detail the corrective actions taken by a licensee in response to individual EOG failures. Following this activity, NRC would be in a much better position to effectively exercise enforcement policy, as appropriate.

3.

Accelerated Testing - the provision in the proposed rule to reduce failures below the double trigger values within 30 days and in the regulatory guide under section 3.3, "Recovery from a Double Trigger," to enter an accelerated testing mode, are inappropriate, impractical, and degrades the EOG. The NRC's sponsored research as part of the Nuclear Plant Aging Program (NPAR) concludes that accelerated testing exacerbates the wear and tear on EDGs and reduces EOG life expectancy. The form of accelerated testing as proposed will result in an unprecedented amount of accelerated testing in order to comply with the 30 day time limit. This use of accelerated testing following a double trigger exceedance is arbitrary and not at all consistent with prior NRC staff discussions nor consistent with NUMARC 87-00, Appendix D, and Initiative 5A. The Appendix D guidance stresses a comprehensive 2

4.

5.

6.

7.

progra11111atic review in response to the double trigger exceedance to identify needed improvements. Improvements in reliability can only be realized over time as corrective actions and progra11111atic changes take effect. Trying to arbitrarily force some indication of this improvement into a 30 day time period is not only detrimental to the EDGs, but also does nothing to correct the underlying problems. We firmly maintain our position that accelerated testing of any form is contrary to the tenet of a reliability program. Backfjttjng Aspects - the Station Blackout rule does not envelope the proposed rule. It is stated in the Federal Register notice that a backfit analysis for the proposed rule was not necessary because the backfit analysis for the SBO rule "specifically indicated that licensees would be required to maintain a reliability level" and "essentially enveloped the requirements of this proposed rule." At the same time, however, under the section "Need for the Proposed Amendment," it is noted that "the SBO rule did not require licensees to monitor and maintain reliability values." Thus, the statements regarding the SBO backfit analysis are contradictory. Nevertheless, a current assessment of the expected improvements to safety and costs associated with the proposed rule is warranted and necessary to comply with 10 CFR § 50.109. Clearly, the additional reporting requirements and additional accelerated testing called for in the proposed rule were not considered in the original SBO rule backfit analysis since these are new regulatory positions. Also, we are not aware of any analysis of the expected benefits/safety improvements to be gained by the proposed rule. Thus, we believe that a backfit analysis for the proposed amendment is necessary. Definitions - Section 2.1 of the regulatory guide should endorse the definitions used for reporting data to the industrywide program on plant performance indicators as specified in NUMARC 87-00, Appendix D. This would ensure that all end-users are applying the same definitions across the board in a consistent fashion. The definitions contained in the regulatory guide lack several clarifications that have been implemented in the industry program. Unavailability - the proposed rule and regulatory guide should not address unavailability. The maintenance rule, technical specifications, and industrywide performance indicators already address this topic. Surveillance Testing - There appears to be a typographical error in Table 1 under the "IO-year tests" column. All tests except for the Redundant Unit Test should be moved under the "Refueling Outage" column. We believe the "fast-start test" frequency should be changed from every six months to every refueling outage, which would be more consistent with the intent of Generic Letter 84-15. This test has been found to be the most detrimental to EDGs. Continuance of the six month frequency is counterproductive to safety in terms of EOG availability. 3

ENCLOSURE 3 C011111ents on AEOD/S91-0l, Special Study Report on Performance of Emergency Diesel Generators in Restoring Power to their Associated Safety Buses - A Revi ew of Events Occurring at Power The AEOO reviewed operating experience of emergency diesel generators (EOGs) to restore electrical power to a safety bus. The failures presented in the report include both the EOG being out of service for maintenance and the total EOG system (including output breaker, sequencer, and support systems) failing to actuate. This report concluded that there were at least three and possibly as many as nine failures of EOGs to power their respective buses out of about 120 challenges. We have reviewed these events and conclude that only one of the noted events represents a failure of the emergency power source to power its bus. We offer the following comments on this report: Contrary to the assertion on page 7 that failure of the service water pumps to automatically load on their associated buses would be considered an EOG failure in draft Regulatory Guide 1.9, revision 3, manual intervention to prevent a failure is allowed. As long as the manual action is accomplished within a few minutes, the exceptions (bullet 4) on page 12 of draft Regulatory Guide 1.9 exempt events 23 and 71 from failure. In this regard, it should be noted that in both cases there was no interruption in EOG operation, and thus no reason to classify the events as failures. In contrast, had either event included an overtemperature trip of the EOG, requiring significant problem diagnosis, and a consequent delay of more than a few minutes in restarting and reloading t he EOG, then that event would have been a failure. Seven of the 14 listed failure events in the report (17, 34, 47, 55, 58, 61, and 91) should have been classified as bus unavailability events, rather than demand failures of a standby emergency AC power source. The Class IE busses are continuously energized, but occasionally an event occurs, typified by these seven events, deenergizing the bus and preventing reenergization by any power source, including the standby emergency diesel generator. These events should not be considered valid demands on the emergency AC power source. For risk analysis purposes, these events would be treated as a bus unavailability term. From the events, it appears that bus unavailability would be a relatively much smaller term in a fault tree than either EOG unavailability or EOG unreliability. As long as there is no common cause way of causing bus unavailability of more than one Class IE bus at a time, (i.e., bus unavailability remains a random event), than there appears to be little contribution to risk caused by a relative handful of these short duration events. In this regard, note that in all seven of these events, the remaining Class IE busses were not only available but remained powered from a normal power source.

Considering the rema1n1ng five events in which an EDG did not successfully respond to a valid demand, four of these events occurred because the EDG was out of service for maintenance (events 6, 11, 43, and 66). The report points out that in Regulatory Guide 1.155 (Station Blackout), unavailability of an emergency AC power train was assumed to be less than one percent. (The actual number assumed was 0.7 percent.) Industry data shows that the average EDG unavailability for preventive maintenance, corrective maintenance, and testing has been twice this assumed value. Consequently, the expected number of times that the EDG would have been out of service for maintenance in the set of actual demands in the AEOD report is two. There were actually four events in the set, which is about one-third as likely an outcome as two events (9 percent vs. 27 percent), so it is not particularly surprising that in four events, an EDG was out of service for maintenance. This outcome does reflect what industry EDG unreliability and unavailability data has been showing for several years--that the emergency AC power source is as likely to be out of service for maintenance as it is to fail in response to a valid demand. Considering the set of 121 valid demands, only one event (number

37) resulted in failure of the emergency AC power source.

Given existing industrywide emergency AC unreliability data, approximately 1.5 percent unreliability, the expected number of failures in the AEOD set would have been two. That one failure would have occurred is equally probable. (Each outcome has about a 27 percent chance of occurring.) Therefore, the industry reported average unreliability of 1.5 percent is supported by the events in the AEOD study. 2

ENCLOSURE 4 COMMENTS ON THE APPLICATION OF A PERFORMANCE BASED REGULATORY APPROACH NUMARC supports NRC efforts to utilize a performance based regulatory approach for new regulatory requirements as well as for improvement of existing regulations. The proposed amendment to 10 CFR § 50.63 represents the first attempt by NRC to implement this approach. While we do not believe that the proposed amendment is needed, the following comments are provided for consideration in applying a performance based approach in the future. From an industry perspective, performance based regulations (PBR) can not and should not be added as a supplemental layer of regulation. It should be a preferred alternative to a prescriptive approach that specifies how licensees should comport with rules. The benefit and promise of PBR is that it would allow both licensees and NRC to allocate resources in a more effective manner and would stimulate initiative on the part of licensees in meeting specified performance criteria.

2.

For the most part, the proposed amendment is consistent with the PBR philosophy. The licensee is allowed to determine how to maintain EDG reliability, and a clear and simple regimen (the trigger values) is used to indicate status against the specified performance criteria.

3.

The major problem we see with the proposed amendment is in its application of enforcement. As stated in Enclosure I, we do not believe a change to enforcement policy is warranted because sufficient basis for regulatory action already exists. In the discussion of enforcement considerations, NRC cites the potential application of Criterion XVI of Appendix B, Corrective Actions, following a report on exceeding the 3/20 trigger. We believe this intent is totally contrary to the PBR philosophy. A more appropriate time to cite this as basis for regulatory action is after exceeding the double trigger, i.e., when the performance criteria has not been satisfied, and it is also the time to allocate more licensee and NRC resources (e.g., focused inspection activity by NRC and comprehensive program evaluation by licensee). Prior to reaching that threshold, the licensee should be allowed to respond to failures without regulatory involvement (which would certainly entail allocation of additional NRC and utility resources). That is the fundamental tenet of PBR. The enforcement discussion goes on to propose additional penalties after exceeding the double triggers (Severity Level III violation and near certain escalated enforcement action). This is inconsistent with current enforcement policy that considers all relevant factors such as corrective action. (see Encl. 2 comment no. 2). I

bocKET NUMBER Pl -s..[.) __ PROPOSED RULE UNITED STATES C ~-; F fl, J 'i 51 V NUCLEAR REGULATORY COMMISSION WASHINGTON. D. C. 20555 .ULhL!i.. U5NHC

• 92 JUL -2 A11 :08 JUL l 1992 MEMORANDUM FOR:

Emile Julian, Chief Docketing and Services Branch Office of the Secretary FROM:

SUBJECT:

Karl Kniel, Branch Chief Reactor and Plant Safety Issues Branch Division of Safety Issue Resolution Office of Nuclear Regulatory Research TRANSMITTAL OF COMMENTS RECEIVED ON THE PROPOSED REVISION TO THE STATION BLACKOUT RULE, 10 CFR 50.63. Enclosed are comments on the proposed revision to 10 CFR Part 50.63 prepared by Mr. T. Dunning. Please docket these comments so that they may become part of the record for the proposed 10 CFR Part 50.63 rule (57 FR 14515 dated April 21, 1992). Should you have any questions concerning the enclosed document, please contact Aleck Serkiz at 492-3942.

Enclosure:

Memo from T. Dunning to A. Serkiz dated May 28,1992. ~w Karl Kniel, Branch Chief Reactor and Plant Safety Issues Branch Division of Safety Issue Resolution Office of Nuclear Regulatory Research

DOCKET NUMBER Pl PROPOSED RULE 5* 0 - ( 5, F ~ /'-/ S' 1 '--/) May 28, 1992 NOTE FOR: A. Serkiz, RPSIB/OSIR/RES

• 92 JUL -2 A11 :08 FROM:

T. Dunning, OTSB/OOEA/NRR rr11* 1 ,-,, 3C1,1,t ;1\\r<

• ~()l°Kl1~NG,, '*t,V\\Cf lJ

' l.

SUBJECT:

PROPOSED REVISION OF THE STATION BLACKOUT RULE, 10 88*

• L5'0.63 The proposed revision to the station blackout (SBO) rule includes an new Section (d) as follows:

Compliance with 50.63(a)(3): Each light-water-cooled nuclear power plant licensed to operate on [date of publication], must comply with 10 CFR 50.63(a)(3) six months after the rule becomes effective. Current plant technical specifications (TS) are more restrictive with respect to some of the reporting and testing requirements for emergency diesel generators than the proposed revision to the SBO rule that are addressed in Section (a)(3). Therefore, the rule should make it clear that the new provisions of Section (a)(3) replace existing requirements for reporting failures of emergency diesel generators and for increasing the frequency of the monthly tests of emergency diesel generators in plant TS. The change should be similar to what was included in 10 CFR 50.73(9) for the license event report rule that superseded reporting requirements for "Reportable Occurrences." It is recommended that Section {d) of 10 CFR 50.63 be expanded by including the following: At that time, the requirements in this section replace all existing requirements for licensees to report diesel generators failures and to increase the monthly test frequency for di~~-

• g ~ ~r-in individual plant Technical Specifications. ~* n

, &.*** **')1..-r, "f* I - ' *,v :,. ~i Without this change, licensees would have to comply wvfh* not-.-0.nl'y 0.63(a)(3 ), but also an more,estrictive diesel generator requirement? imposed by the TS. This would be the situation until such time as the l iceri'se.. ;aP13~1ed for and was granted a TS change to remove those requirements, based upon the revi sed ru l e * .fl

• cc:

0. Chopra M. Reinhart

. -- b;i. :.; "... 17.-:. CD

U:S. NUCLEAR AEOULATORY COMMISSK>t-DOCKETING & SERVICE SECTION OFFICE OF THE SECRET ARY OF THE COMMISSION Document Statistics Postmark Dam le e.+/- b '1 s r<<JJF Copies Received ______ -/_ Add'I Coplls Reproduced ____ Specill llsritulon Pt} f2. f[I J?& s--_ rf<;--1 7--

AGENCY: ACTION:

SUMMARY

• r ocKET NUMBER PR PROPOSED RULE...;;..:;;::............ -

(57 FR 145/L/) 10 CFR Part 50 RIN 3150-AE06 DOCKETED USNHC

• 92 APR 16 A10 :54 Loss of all Alternating Current Power Nuclear Regulatory Commission.

Proposed rule. (7590-01] The Nuclear Regulatory Commission is proposing to amend its regulations regarding the reliability of onsite alternating current (ac) sources for light-water-cooled nuclear power plants. The reliability of onsite emergency ac sources is a major factor in assuring acceptable safety at light-water-cooled nuclear power plants. The proposed amendments would require licensees to test and monitor emergency diesel generators (EOG) against criteria that indicate possible degradation from the EOG target levels selected for determining the specified station blackout duration. 7/6/9:L DATES: Comment period expires (75 days after publication date], 1992. Comments received after this date will be considered if it is practical to do so, but the Commission is able to assure consideration only for comments received on or before this date. ADDRESSEES: Convnents may be sent to: The Secretary of the Commission, U.S. Nuclear Regulatory Commission, Washington, DC 20555, ATTN: Docketing and Service Branch.

[7590-01] Deliver comments to: 11555 Rockville Pike, Rockville, Maryland, between 7:45 am and 4:15 pm Federal workdays. Copies of comments received may be examined at the NRC Public Document Room, 2120 L Street NW. {Lower Level), Washington, DC. FOR FURTHER INFORMATION CONTACT: Aleck Serkiz, Division of Safety Issue Resolution, Office of Nuclear Regulatory Research, U.S. Nuclear Regulatory Commission, Washington, DC 20555, Telephone {~01)492-3942.. SUPPLEMENTARY INFORMATION:

Background

The Commission's exi_sting regulations {See General Design Criteria 17 and 18, 10 CFR Part 50, Appendix A) establish requirements for the design and testing of onsite and offsite electric power systems that are intended to reduce the probability Qf losing all ac power. The statement of considerations for the Station Blackout rule {SBO) (53 FR 23203; June 21, 1988) noted that the reliability of onsite emergency ac power sources is one of the main factors contributing to risk of core melt resulting from station blackout. The statement of considerations also noted *that resolution of Generic Safety Issue B-56, Diesel Generator Reliability, would provide specific guidance for use by the staff or industry to "review the adequacy of diesel generator reliability programs consistent with the resolution of USI A-44 (Station Blackout)." 2

[7590-01] The NRC guidance for EOG selection, design, qualification and testing is currently provided in the following three documents: (1) Regulatory Guide 1.9, Revision 2, (2) Regulatory Guide 1.108, Revision 1, and (3) Generic Letter 84-15. The Co11111ission has determined that an amendment to 10 CFR 50.63 is the appropri-ate means for imposing new requirements related to emergency diesel generator (EDG) testing and monitoring against a performance based criteria. Need for the Proposed Amendment If a loss of normally available (ac) power occurs at a nuclear power plant, redundant onsite emergency ac power sources provide power for necessary safety functions which include reactor core decay heat removal (GDC 34), emergency core cooling (GDC 35), and containment heat removal (GOC 38). These systems are essential for preserving the integrity of the reactor core, reactor coolant system, and containment. Although reactor core decay heat can be removed for a limited time by systems that are independent of ac power, Class lE *EDGs have been selected by most licensees as the long term ac power sources in most plants for meeting the requirements of the Station Blackout Rule, 10 CFR 50.63. Therefore, the reliability of EDGs is a major factor in assuring acceptable plant safety. The Commission has determi'ned that a rule requiring EOG testing and monitoring is necessary in light of the reliability target selected by the licensee in determining the specified station blackout duration required by 10 CFR 50.63(a). Licensees were*required to select EDG target reliability values in determining the specified station blackout duration required by the Station 3

(7590-01] Blackout rule (SBO), 10 CFR 50.63(a). However, the SBO rule did not require licensees to monitor and maintain these reliability values. As a result, the Commission has determined that new requirements are needed for appropriate EOG testing and monitoring against EOG performance based criteria. The Commission believes that EOG monitoring should be based on a results-oriented approach, consistent with the approach taken in the maintenance rule (56 FR 31306; July 10, 1991). This approach would consist of (1) -establishment of EOG target reliability levels that _would comport with the reliability levels assumed in a licensee's coping analysis for s!ation blacko~t, (2) trigger values with respect to EOG failures, to serve two purposes -- to provide a warning of EOG degradation, and to provide a basis for taking regulatory action when there is -reasonable evidence from surveillance testing that EOG reliability degraded below selected target levels, and (3) a reporting regime for EOG failures consistent with the approach described above. Monitoring of EOG Performance -The monitoring -0f EOG performance (i.e., failures and successes) will be based primarily on surveillance tests which subject the diesels to "start" and "load-run° cycles as discussed in the proposed revision of Regulatory Guide 1.9, (Revision 3). In addition, unplanned starts and load-runs will occur during the nonnal operations cycle. The combination of surveillance tests and unplanned EOG start and load-run demands will provide data for EOG monitoring and indicating degradation from target reliability val~es selected for detennining the specified station blackout duration. The overall goal is to develop a method that maximizes the probability of detecting a significant decrease in EOG reliability while minimizi-ng the probability of indicating a 4

[7590-01] decrease when none actually occurred (a false alarm). These are competing requirements. The following "double trigger" values were selected, as a basis for regulatory action, and strike a balance between these competing requirements: Nuclear Unit EOG Target Reliabj]ity 0.95 0.975 Double Trigger {Fajlures/Demands) 5/50 and 8/100 4/50 and 51100 The trigger values should not be viewed as a statistical estimate of target unit EOG reliability, but rather as a threshold at which there is reasonable evidence that EOG reliability has degraded below target levels. These triggers are based on the tota 1 number of failures and demands for a 11 of the EDGs at a nuclear unit. However, the response time is slow. Assuming monthly testing plus unplanned demands, two years could pass before 100 demands occurred. In order to monitor EOG performance and to provide' a warning of possible degradation, a 3/20 trigger would also be applied to the performance of any individual EOG and of all EOGs assigned to a nuclear unit. In addition, a trigger of 4 failures in the last 25 demands *on any individual EOG is a further indication of possible degradation for an EOG and of the ineffectiveness of any corrective action taken. 5

[7590-01] In summary, monitoring of EOG performance for reporting to the NRC would be based on monitoring failures and successes to start and load-run, and utilize the following criteria:

1)

If there are 3 failures within the last 20 demands for either an individual EOG or for all EDGs assigned to a nuclear unit, this is an early indicator of possible deterioration of EDG reliability. The licensee shall submit a written report to the NRC within 30 days of reaching. this failure con~ition which ~tates the cause(s) for this condition and provides the nuclear unit's EDG failure history within the last 100 demands.

2)

If there are 4 failures in the last 25 demands of an EOG, this is a further indication of possible deterioration of EDG reliability. Following corrective action, this EOG should be subjected to accelerated testing to demonstrate effectiveness of maintenance actions (i.e., 7 consecutive failure free tests). The licensee shall also submit a written report to the NRC within 30 days of reaching this failure condition which states the cause(s) for this condition, and the planned corrective action and provides the failure history within the last 100 demands for the EOG.

3)

DOUBLE TRIGGER: If there are 5 failures within the last 50 demands and 8 failures within the last 100 demands (nuclear unit target reliability - 0.95), or 4 failures within the last 50 demands and 5 failures within the last 100 demands (nuclear unit target reliability - 0.975), then this is reasona~le evidence that 6

[7590-01] EOG reliability has degraded below the target reliability level selected by the licensee in determining station blackout duration and recovery. This condition constitutes non-compliance with §50.63(a) and regulatory action should be taken. The actions and reporting requirements of §50.63(a)(3)(i)(C) should be carried out. A single EOG failure on demand due to a coltlllon cause problem, while reportable, does not get special treatment in terms of its contribution to a trigger value. However, since a licensee Ev_ents Report,LER) will have been generated, adequate opportunity for NRC review is already provided for this relatively infrequent occurrence outside of the criteria discussed above. It should also be clearly recognized that use of the trigger values discussed above do not alone give sufficient assurance that target reliabilities are being maintained. Implicit in a performance based rule such as this, is the assumption that licensees will implement EOG maintenance* programs that correct root causes of failures. Thus the trigger concept should not be viewed as a statistical estimate of the EOG reliability, but rather as a method to identify the potential degradation of reliability. In light of this discussion, the Corrmission solicits views on the following questions:

1.

Is there a better way to identify EDG degradation than the proposed trigger values, which is practical for use by licensees, and which will improve detection of reliability degradation while minimizing false alarms? 7

[7590-01]

2.

Is there a method which could utilize industry-wide EOG performance experience to monitor EDG reliability, while providing adequate reliability degradation information for plant specific use? For example, The Bayesian method, the James-Stein estimator, the jackknife and the bootstrap are all methods which might improve diesel reliability assessment.

3.

In addition, in light of current industry EOG performance, other applicable NRC_regulations ~nd the future requirements of the maintenance rule (10 CFR 50.65), is this proposed rule needed to provide continued confidence in the reliability of EOGs and in maintaining the underlying reliability basis used for the Station Blackout rule?

4.

In developing the EDG reliability levels selected for the SBO rule, the unavailabil1ty due to testing and maintenance was assumed to contribute only a small amount (.007) to overall una~ailability. In turn, this proposed rule does not include a specific limit on EOG unavailability. A recent evaluation (AEOD Special Study Report AEOD/S91-01, September 1991) of

• operational events during calendar years 1985-1990 --

involving EOG performance following bus undervoltage condiiions --, however, indicated a higher than 8

[7590~01] expected EOG unavailability due to maintenance (five of 128 EOG start demands occurred while the EOG was out of service for maintenance). The Commission solicits.views on the need for this rule to additionally address unavailability. Enforcement Considerations The 3 failures in the last 20 demands warning report 1s subject to NRC review or inspection to detennine underlying causes and corrective actipns planned or carried out. Enforcement action w~ll not be t~ken solely as a result of this warning report, but some action(including escalated acti~n) may result from associated staff activities should violation of other requirements such as Criterion XVI of Appendix B of 10 CFR 50 be identified. The severity level for a licensee's failure to report reaching the 3/20 warning or 4/25 EOG condition will be evaluated on a case-by-case basis. Occurrence of the double trigger is reasonable evidence that the nuclear unit EDG reliability level has degraded below the reliability target selected by the licensee in determining the specified station blackout duration required by 10 CFR 50.63(a) and therefore regulatory action should be taken. The actions and reporting requirements of §50.63(a)(3)(ii){C) should be carried out. The Commission intends, as part of the final rulemaking in this matter, to modify the NRC enforcement policy in 10 CFR Part 2, Appendix C. Specifically, the Commission would modify Supplement I of Appendix C to 9

[7590-01] identify that failure to report occurrence of "double trigger" conditions as required by this rulemaking is an example of a Severity Level III. In addition, the Commission would modify Supplement I to provide that failure to take corrective action as required by Appendix B of Part 50 so that the double trigger value in 10 CFR 50.63(a)(3)(ii)(C) is reached would be considered an example of a Severity Level III violation. Civil penalties are normally assessed for Severity Level III violations absent mitigating conditions. It is normally expected that the_double trigqer would he exceeded after occurrence of the 3/20 warning trigger in §50.63{a)(3){ii)(A) with the licensee not taking effective corrective action. Thus, it may be appropriate in assessing a civil penalty to escalate the penalty for prior notice and not to mitigate the penalty for prior performance. The licensee's response to exceeding the double trigger may be considered in determining if daily civil penalties sho~ld be imposed for each day the facility operated while exceeding the double trigger level. By these enforcement positions, the Commission-will be emphasizing the importance of having reliable diesel generators. This rule does not prohibit operation of a facility with diesels having less than the expected reliability provided the diesels are operable as required by the facility's technical specifications action statements. However, prior to making the decision to operate with less than the expected EOG reliability and face daily civil penalties, the licensee must make the required operability evaluation, as it must whenever a diesel fails, and follow the technical specifications if a diesel is determined to be inoperable. 10

[7590-01] Finding of No Significant Environmental Impact: Availability The Corrmission has determined under the National Environmental Policy Act of 1969, as amended, and the Commission's regulations in Subpart A of 10 CFR Part 51, that this rule, if adopted, would not be a major Federal action ~ significantly affecting the quality of the human environment and therefore an environmental impact statement is not required. The environmental assessment and finding of no significant impact are available for inspection and copying for a fee at the NRC Public Document Room, 2120 L Street, NW. (Lower Level) Washington, DC between the hours of 7:45 am and 4:15 pm on Federal workdays. Single copies of the environmental assessment and finding of no significant impact are available from Mr. Aleck Serkiz, Office of Nucl~ar Regulatory Research, U.S. Nuclear Regulatory Cofllllission, Washington, DC 20555, Telephone: (301) 492-3942. Paperwork Reduction Act Statement This proposed rule amends information collection requirements that are subject to the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.). This rule has been submitted to the Office of Management and Budget for review and approval of the paperwork requirements. The public reporting burden for this collection of information is estimated to average 492 hours per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection 11

[7590-01] of information, including suggestions for reducing this burden, to the Information and Records Management Branch (MNBB-7714), U.S. Nuclear Regulatory Convnission, Washington, DC 20555, and to the Desk Officer, Office of Information and Regulatory Affairs, NEOB-3019, (3150-0011), Office of Management and Budget, Washington, DC 20503. Regulatory Analysis The Commission did not prepare a separ!te regulatori analysis for the proposed rule, because the existing regulatory analysis (NUREG-1109) for the Station Blackout rule assumed, and therefore considered, the need for licensees to monitor their emergency diesel generators against criteria consistent with EOG reliability levels selected for determining station blackout coping capability. The proposed rule requires licensees to monitor emergency diesel generators and take appropriate action if there is reasonable ~ evidence that their reliability has degraded below the reliability targets esta9lished by the licensees in conformance with the requirements of §50.63(a)(l) of the Station Blackout rule. However, as the backfit analysis for the Station Blackout rule makes clear, monitoring and reliability-achievement requirements were presumed to be part of the regulatory scheme for the Station Blackout rule. The resolution of USI A-44 wstation Blackout" (see 53 FRN 23217-8) included issuance of Regulatory Guide 1.155, wstation Blackout" which described a means acceptable to the staff for meeting the requirements of 10 CFR-50.63. Regulatory Guide 1.155 noted that EOG rel1ab1lity should be targeted at*0.95 for Group A, Band C plants, and at 0.975 for Group D plants 12

[7590-01] for determining the coping duration for a station blackout and further noted that each p1ant should have an EOG reliability program containing the principal elements, or their equivalent, as outlined in Regulatory Position 1.2. The rule further noted that the resolution of Generic Safety Issue 8-56 (a safety issue related to USI A-44) would provide specific guidance for use by the staff or industry to review the adequacy of EOG reliability programs consistent with the resolution of USI A-44. The Convnission now believes that detailed prescriptiye guidance on the content of emergency diesel generator reliability monitoring p,rograms is,not warranted. Therefore the proposed rule sets forth the requirement for-,. - surveillance testing, establishes criteria for determining whether reliability may have fallen below selected target values and specifies the actions to be taken. However, since the requirements in the Station Blackout rule and-its regulatory analysis indicated that such monitoring of EOG would be performed, the Commission believes that a new regulatory analysis for the proposed rule which explicitly establishes these actions as regulatory requirements would be largely duplicative. Moreover, the regulatory analysis for the Station Blackout r~le indicated that most licensees were already performing some type of reliability monitoring, and that only 10 licensees would be required to incur additional costs for upgrading their diesel generato~ monitoring programs. The Commission does not believe that licensees have reduced their monitoring since the preparation of the regulatory analysis for the Station Blackout rule. 13

[7590-01] Therefore, the Commission concludes that the cost estimates for this proposed rule, are enveloped by the regulatory analysis for the Station Blackout rule. For these reasons, a new regulatori analysis for this proposed rule was not prepared. Regulatory Flexibility Certification As required by the Regulatory Flexibility Certification Act of 1980, 5 U.S.C. 605(b), the Commission certifies that, if promulgated, this rule will not have a significant economic impact upon a substantial number of small entities. The proposed rule would specifically affect light-water-cooled nuclear power reactor licensees. These licensees do not fall within the definition of small businesses as defined in Section 3 of the Small Business Act' (15 U.S.C. 632), t~e Small Business Size Standards of the Small Business Administration (13 CFR Part 121) or the Commission's Size Standards (56 FR 56671; Nov. 6, 1991). Backfit Analysis The proposed rule establishes requirements for monitoring emergency diesel generators and requires licensees to take appropriate action if.there is reasonable evidence that EOG reliability has fallen below the reliability targets established by the licensees in determining the specified station blackout duration required by §50.63(a){l) of the Station Blackout rule. The backfit analysis for §50.63, that was published in the Federal Register along with the final rule (53 FR 23210; June 21, 1988), specifically indicated that 14

[7590-01] licensees would be required to maintain a reliability level of either.95 or .975, and included the costs for development of procedures and corrective actions if reasonable evidence indicated that diesel generator reliability had fallen below the selected reliability levels. lli 53 FR* at 23216, 23217. Thus, the backfit analysis for the Station Blackout rule essentially enveloped the requirements of this proposed rule. Costs associated with this rule amendment (including reporting requirements not explicitly identified in the S80 regulatory analysis) are bounded by the cost estimates dealing with improvement' of EOG reliability and requalification of EOGs_ disc4ssed in NUREG- . 1109. Preparation of a new backfit analysis for this proposed rule would be duplicative of the prior backfit analysis with respect to monitoring and,: testing diesel generators. For*this reason, a new backfit analysis for the proposed rule was not prepared. As set forth in the prior backfit analysis for the Station Blackout Rule, the Conunission concludes that the testing and monitoring requirements in this proposed rul~ will provide a substantial increase in the overall protection of the public health and safety and-that the costs of the proposed requirements are justified in view of the increased protection to the public. Alternatively, the Commission believes that the "compliance exception" of the Backfit Rule, 10 CFR 50.109(a)(4)(i) is applicable to the proposed rule. As discussed above, the testing and monitoring requirements.of the proposed rule are consistent with the §50.63(a)(l) licensee-specified diesel generator reliability targets. Under the §50.109(a)(4){i) of the Backfit Rule, a backfit analysis need not be prepared where the backfit*is necessary to bring a licensee into compliance with the Conunission's requirements. In the Commission's view, §50.109(a){4){i) is applicable to this proposed rule 15

[7590-01] and precludes the need to prepare a new backfit analysis for the proposed rule. Conments are requested from the public as to the applicability of §50.109(a)(4)(i). List of Subjects In 10 CFR Part 50 Antitrust, Classified information, Criminal penalty, Fire protection, Incorporated by reference, Intergovernmental relations, Nuclear power plants and reactors, Radiation protection, Reactor siting criteria, Reporting and recordkeeping requirements. For the reasons set out in the preamble and under the authority of the Atomic Energy Act of 1954, as amended, the Energy Reorganization Act of 1974, as amended, and 5 U.S.C. 553, the NRC is proposing to adopt the following amendment to 10 CFR Part 50. I. PART 50 - DOMESTIC LICENSING OF PRODUCTION AND UTILIZATION FACILITIES The authority citation for Part 50 continues to read as follows: AUTHORITY: Secs. 102, 103, 104, 105, 161, 182, 183, 186, 189, 68 Stat. 936, 937, 938, 948, 953, 954, 955, 956, as amended, sec. 234, 83 Stat. 1244, as amended (42 U.S.C. 2132, 2133, 2134, 2135, 2201, 2232, 2233, 2236, 2239, 2282); secs. 201, as amended, 202, 206, 88 Stat. 1242, as amended, 1244, 1246 (42 U.S.C. 5841, 5842, 5846). Section 50.7 also issued under Pub. L. 95-601, sec. 10, 92 Stat. 2951 (42 U.S.C. 5851). Section 50.10 also issued under secs. 16

[7590-01] 101, 185, 68 Stat. 936, 955, as amended (42 U.S.C. 2131, 2235); sec. 102, Pub. L. 91-190, 83 Stat. 853 (42 U.S.C. 4332). Sections 50.13, and 50.54(dd), and 50.103 also issued under sec. 108, 68 Stat. 939, as amended (42 U.S.C. 2138). Sections 50.23, 50.35, 50.55, and 50.56 also issued under sec. 185, 68 Stat. 955 (42 U.S.C. 2235). Sections 50.33a, 50.55a and Appendix Q also issued under sec. 102, Pub. L. 91-190, 83 Stat. 853 (42 U.S.C. 4332). Sections 50.34 and 50.54 also issued under sec. 204, 88 Stat. 1245 (42 U.S.C. 5844). Sections 50.58, 50.91, and 50.92 also issued under Pub. L. 97-415, 96 Stat. 2073 (42 U.S.C. 2239!. Section 50.78 also issued under sec. 122, 68 Stat. 939 (42 U.S.C. 2152). Sections 50.80 - 50.81 also issued under sec. 184, 68 Stat. 954, as amended (42 U.S.C. 2234). Appendix Falso issued under sec. 187, 68 Stat. 955 (42 u.s.c 2237). For the purposes of sec. 223, 68 Stat. 958, as amended (42 U.S.C. 2273); §§ 50.5, 50.46(a) and (b), and 50.54(c) are issued under sec. 161b, 68 Stat. 948, as amended (42 U.S.C. 2201(b}); §§.. 50.5, 50.7(a), 50.lO{a)-(c), 50.34(a} and {e), 50.44(a)-(c), S0.46(a) and (b), 50.47(b), 50.48(a), (c), (d), and (e), 50.49(a), 50.54(a), (i), (i)(l), (1)-(n), (p), (q), (t), (v), and (y), 50.55(f), 50.55a(a), (c)-(e), (g), and {h), 50.59{c), 50.60(a), 50.62(b), 50.64{b), 50.65, and 50.80(a) and (b) are issued under sec. 16li, 68 Stat. 949, as amended (42 U.S.C. 2201(1)); an~ §§50.49(d), {h), and {j), 50.54(w), (z), {bb), (cc), and {dd), 50.55(e), 50.59{b), 50.6l(b), 50.62{b), 50.70(a), 50.71(a)-{c) and {e), 50.72(a), 50.73(a) and (b), 50.74, 50.78, and 50.90 are issued under sec. 1610, 68 Stat. 958, as amended (42 U.S.C. 2201(0)). 17

[7590-01]

2.

Section 50.63 is amended by adding paragraphs (a)(3) and (d} to read as follows: §50.63 Loss of all alternating current power. (a) {3)(i) The reliability of every emergency diesel generator must be monitored by testing at least monthly. All data from planned and unplanned demands must be used in monitoring the emergency diesel generator reliability. The starti~g baseline nuclear unit failure history will be based on all emergency diesel failures that have occurred in the last 100 demands of all the emergency diesel generators for that nuclear unit immediately prior to the effective rule date. The following criteria will be used for reporting EOG performance and corrective action to the NRC. (A) If there are 3 failures out of the last 20 demands for either an individual emergency diesel.generator or at any nuclear unit (i.e. combining the performance data for all emergency diesel generators assigned to a given nuclear unit rather than based on each individual emergency diesel generator), the licensee shall submit a written report to the NRC within 30 days of reaching the failure condition of this paragraph stating the cause(s) for this condition and the nuclear unit's EOG failure history for the last 100 demands. (B) If there are 4 failures out of the last 25 demands of an emergency diesel generator, the licensee shall test that emergency diesel generator at a period between tests of no less than 24 hours and no more than 7 days, until 7 consecutive failure free tests are 18

[7590-01] achieved, or the emergency diesel generator passes alternative tests that have been approved by the NRC. The licensee shall submit a written report to the NRC within 30 days of reaching the failure condition of this paragraph stating the cause(s) for this condition, the nuclear unit's EDG failure histoty within the last 100 demands, and planned corrective action. (C) If, for a selected reliability target of 0.95, there are 5 failures within the last 50 demands* and 8 failures within the last 100 demands,.or for a selected reliability_ target of O. 975, there are 4 failures within the last 50 demands and 5 failures within the last 100 demands at any nuclear unit (i.e., combining the perfonnance data*for all emergency diesel generators assigned to a given nuclear unit rather than to each individual emergency diesel generator), reaching the applicable failure condition set forth in this paragraph will also be deemed to be a noncompliance with the requirements of paragraph (a)(2) of this section. If the above failure criteria occur, the licensee, shall: {l) implement appropriate corrective action; (Z) notify the NRC Operations Center within four hours; and (1) if the EOG failures have not been reduced to less than those noted above within thirty days of the occurrence of the above failure criteria, send a written report to the Director, Nuclear Reactor Regulation stating the cause(s) for this condition, the basis on which the EDGs are considered operable, and a description and schedule for corrective action. (D) Licensees shall retain in an auditable and retreivable form all infonnation and documentation required by, or otherwise necessary to document compliance with the pr~visions of subparagraph (a)(3)(i). 19

[7590-01] (d) Each light-water-cooled nuclear power plant licensed to operate on [date of publication], must comply with 10 CFR 50.63(a)(3) six months after the rule becomes effective. Dated at Rockville, Maryland, this ~ S" day of -A-r-&,1992 r Regulatory Conmission. amuel J. Chilk Secretary of the Commission. 20

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