ML20043H321
| ML20043H321 | |
| Person / Time | |
|---|---|
| Issue date: | 06/19/1990 |
| From: | Beckjord E NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | Jordan E Committee To Review Generic Requirements |
| Shared Package | |
| ML20043H318 | List: |
| References | |
| REF-GTECI-B-56, REF-GTECI-EL, TASK-B-56, TASK-OR NUDOCS 9006250184 | |
| Download: ML20043H321 (65) | |
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JUN 191990 i
NENORANDUM FOR:
Edward L. Jordan, Chairman Committee to Review Generic Requirements FRON:
Eric Beckjord, Director Office of Nuclear Regulatory Research
SUBJECT:
CRGR REVIEW OF PROPOSED RESOLUTION OF GENERIC SAFETY ISSUE 3-56, " DIESEL RELIABILITY"
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I The purpose of this memorandum is to request that the revised proposed resolution of Generic Safety Issue B-56 be scheduled for review by the CRGR in July 1990.
Na have followed through on the recommendations made by the CRGR i
on December 20,1989 (Ref. CRGR Noeting Number 176) and have had discussions with NUMARC regarding the use of Appendix D of NUMARC-8700 as the principal reference for monitoring and maintaining EDG reliabilities selected for compliance with 10 CFR 50.63, " Station Blackout".
NUMARC bas revised NUNkRC-8700, with the following changes:
1.
Initiative 5 of NUMARC-8700, 10/19/87, has been revised to include monitoring of EDG reliabilities against the target reliability selected for Station j
Blackout (SBO), and also addresses actions for a problem EDG experiencing 4 or more failures-in the last 25 demands.
A copy of NUMARC's Initiative SA is L
enclosed.
2.-
NUMARC has revised their Appendix D, "EDG Reliability Program" from the 11/6/89 draft which was discussed at CRGR Ntg. 176.
The current version has been reduced in scope.
The previous guidance dealing with j
surveillance needs, performance monitoring of important EDG parameters, data systems, maintenance, failure analysis and root cause investigation, problem closeout L
and methodology for determining programmatic deficiencies is now being put in a topical report titled " Effective Elements of an EDG Reliability Program."
This Topical Report has not and will not be submitted to the NRC. HUMARC intends to provide this Topical Report only to utilities, as needed.
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2 NN1919g3 Appendix D now consists of two sections:
D1,
" Definitions" and D.2,
" Monitoring EDG Reliability."
i The details of the EDG reliability program are discussed in the Topical Report.
This reduction in i
contents does not provide a means for the direct " total endorsement" approach as recommended by the CRGR.
We recommend that Revision 3 of Regulatory Guide 1.9 reference Appendix D where unambiguous reference can be made to Appendix D, and that guidance related to an on-site EDG reliability program be included in the Regulatory Guide.
Revision 3 of Regulatory Guide 1.9 has been revised accordingly and is responsive to CRGR comments received.
3.
The NUMARC letter (N.B. Rasin to E.S. Beckjord letter l
dated April 27, 1990) notes that NUMARC's Board of Directors has approved Initiative 5A and a revised Appendix D which will be incorporated into NUhkRc-8700, Revision 1.
NUMAPC's submittal does not commit-the industry to impir. mentation of Initiative 5A or l
Appendix D; instand these documents are referred to as guidance.- Utilities could chose not to use it.
Therefore the.*;asolution of GSI 3-56 requires issuance of Regulatory Guide 1.9, Revision '3 and a 50.54 (f) letter requesting identification of actions to be taken by licensees including modification of TS.
A letter (Enclosure C) has been prepared, along with guidance for preparation of a license amendment request to change Technical Specifications (TS).
The TS changes l
consist of line-item changes that are acceptable based on the implementation of programmatic requirements for monitoring and maintaining EDG reliability levels.
The TS changes are a relaxation of those TS based on l
R.G. 1.108.
Not all plants have TS based of R.G.1.108.
4.
Also a draft memo to Project Managers (Enclosure G) has been prepared, with a model SER, for evaluation of the L
licensee response to the generic letter and proposed TS l
changes.
The B-56 Backfit Analysis and Federal Register Notice have been revised in response to CRGR comments.
CRGR comments resulting from CRGR Neeting 170 are discussed in Enclosure A.
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) 's dUk291930 We feel that these changes have been responsive to CRGR's comments and will be prepared to discuss them at the meat CRGR aceting._ If you have questions on the enclosures please contact Al Serkis on 492-3942.
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l Q d..h Alv Eric 5. Beckjor,
Director Office of Nucleat Regulatory Research ENCLO5URES:
- 1. W. B. Rasin to E. S. Beckjord Letter dated 5-3-90
- 2. Enclosure A:
Responses to CRGR Comunents
- 3. Enclosure R:
Regulatory Guide 1.9, Revision 3
- 4. Enclosure C:
Proposed Generic Letter (with Tech Spec Guidance)
- 5. Enclosure D:
Backfit Analysis
- 6. Enclosure E:
FRN Draft Notice
- 7. En%osure F:
NUMhAC-8700, Rev. 1, Appendix D, 5-2-90
- 8. Enclosure G:. Memo to Project Managers w/Model SER s
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.L NUCLW2 MANAGEMIN1 AND etsoveCEs COUNCIL 977c he swee' N W e sste 330
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i May 3, 1990 l
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Dr. Eric S. Beckjord, Director j
Office of Nuclear Regulatory Research
'U.S. Nuclear Regulatory Commission I
Washington, D.C.
20555 4
Dear Dr. Beckjord:
The purpose of this letter is to update you on the NUMARC efforts relating to Generic Issue B 56 Diesel Generator Reliability. These efforts have been focused through the NUMARC Station' Blackout Working Group.. chaired i'
by John Opeka Executive Vice' President, Engineering and Operations, Northcast-
-Utilities.E NUMARC has met numerous times ever the past several months with
. members of the NRC, Staff in seeking a comprehet.she resolutten to this
'important issue. We believe the results of these. efforts as discussed in this l
L1etter provide sufficient basis for closure of B-56, a
. On. March 7, 1990, th's 14UMARC Board of Directors approved a revision to a
'one of the existing' Station Blackout Initiatives. The revised Initiative 5A,
. Coping Assessment /EDG Performance, provides a mechanism for monitoring the EDG target reliability chosen by. utilities as part of the station blackout coping.
= assessment. This initiative also addresses a reduction in accelerated testing
.that will enhance'long term EDG reliability while adequately demonstrating the restored performance of individual EDGs. A copy of the initiative-dated.
-March 7,s1990, is-enclosed for your information.
4 We believe -Initiative SA, establishes reasonaHe! consensus trigger values W
for monitoring the EDG target reliability (0.95 or 0.975) on a plant unit'
< basis. We:further believe the initiative provides an appropriate focus on EDG -
cperformance rather than programmatic activities.. This= focus is supported by.
data compiled by.EPRI andLpublished as NSAC-108..The Reliability of Emeraenev Diesel t,enerators at U.S. Nuclear P%er Plants, as well as by INP0 through the U.S. Industrywide Plant Performance-Indicator Program. The data shows that i
since.1983, the industry average EDG reliability has been above 0.98. This-clearly! indicates that current industry practices are effective in maintainin'g EDG reliability at acceptable levels, and that prescriptive guidance is not e
- warranted in this area.
With regard to the portion of Initiative SA-dealing with accelerated testing :we anticipate utilities will address this reduction through changes to cui rsnt' ple.nt technical specifications.
It is expected that the submitted
~chhnges will be' revitwed and approved by~ the plant specific PRC project managers.-
Furthermore, the NUMARC Technical Sper.ifications Improvement Working Group will. incorporate this reduction in accelerated testing into its effort. on electrical power systems. Discussions are currently underway with
'the appropriate members of the NRR staff. However, because accelerated I
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Dr. Eric 5. Beckjord May 3, 1990 Page 2 necification testing'is one element of a more comprehensive set of technicat letter improvements, we believe a generic communication, e.g., the gene s '
f M 'A
-that addresses closure of the B 56 issue, may be appropriate to m n*.'
f acceptance of the reduction its accelerated testing and further expediN
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approval: process.
In addition to Initiative SA,- the Station Blackout Working Group has DG Reliability Frogram.. A copy dated revised NUMARC'87 00, Appendix 0, E This revision provides a May 2,1990,- is also enclosed for your information.
It includes framework for monitoring and maintaining EDG reliability.
guidance on utilizing the trigger values noted in the initiative and on taking We believe these remedial remedial actions when these values are exceeded. actions provide f the Station Blackout Rule, j
maintained consistent with'the~ intent oThe revised Appendix 0 has been distributed to As l
-and may be used to supp:rt tach utility's implementation of Initiative SA.
10CTRt0.9 noted previously, Appendix 0 has also been the subject of variou revision 3 of Regulatory Guide 1.9 will contain specific language accepting
'with the NRC Staff.
NUMARC 87 00 Appendix 0, as an adequate means of monitoring and maintaining j
a EDG reliability.
i In summary, we believe that Ir.itiative 5A'and the revised HUMARC 87 00, Appendix D, coupled with the high average IDG reliability i
- B 56'..It is our plan to proceed with printing a revision t h
revised Appendix F addressing equipment' operability, supplemental clarifying A copy of the questions / answers. Initiative 5A, and the revised Appendix 0. b Please contact me if you have any question's, if your staff has any questions-relative to the enclosures, they may contact Alex Marion or Tony s
Pietrangelo of the NUMARC staff.
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'Dr. Eric S. Beckjord Z1
,May'3. 1990 Page 3.
Consistent with past practice we understand this transmittal will be placed in the Public Document Room.
Sincerely,
$/ ks.,n k William H. Rasin Director, Technical Division AM/ARP Enclosures 1 C. J. Heltemes, Jr., NRC cc:.
W. Minners, NRC
.A. C. Thadani, NRC A. W. Serkiz, NRC
-J..F. Opeka, Northeast Utilities i
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INITI ATIVE SA.- COPING ASSESSMENT /EDG PERFORMANCE EACH UTILITY WILL ASSESS THE ABILITY OF ITS PLANT (S) TO COPE WITH PLANTS UTILIZING ALTERNATE AC POWER FOR STATION BLACKOUT RESP
- BLACKOUT, WHICH CAN BE SHOWN BY TEST TO BE AVAILABLE TO POWER THE SHUT 00 10 M]NUTES OF THE ONSET OF STATION BLACKOUT DO NOT NEE 0 TO PE REMAINING ALTERNATE AC PLANTS WILL ASSESS THEIR ABILITY TO COPE ASSESSMENT.
PLANTS NOT UTIL121NG AN ALTERNATE AC SOURCE WILL ASSESS THEIR FOR ONE-HOUR.
FACTORS IDENTIFIED WHICH PREVENT ABILITY TO COPE FOR FOUR HOURS.
DEMONSTRATING THE CAPABILITY TO COPE FOR THE APPROPRI ATE DURA ADDRESSED THROUGH HARDWARE AND/OR PROCEDURAL CHANGES S0 THAT SUCCES DEMONSTRATION IS POSSIBLE.
AS PART OF THE COPING ASSESSMENT, UTILITIES ARE REQUIRED TO CHOOSE AN EDG TARGET RELIABILITY (0.95 OR 0.975) AND ARE REQUIRED TO MAINTAIN THAT CH ACCORDINGLY, EACH UTILITY WILL EMPLOY THE FOLLOWING EXCEEDENCE RELIABILITY.
TRIGGER VALUES (ON A PLANT UNIT BASIS) AS THE MECHANISM FOR MONITORIN TARGET RELIABILITY AND TO SUPPORT CLOSURE OF GENERIC ISSUE B-56:
SELECTED EDG TARGET FAILURES IN FAILURES IN FAILURES IN RELIABILITY 20 DEMANDS 50 DEMANDS 100 DEMANDS 0.95 3
5 8
0.975 3
4 5
add!TIONALLY, EACH UTILITY, IN RESPONSE TO AN INDIVIDUAL EDG EXPERIENCING 4 OR MORE FAILURES. IN THE LAST 25 DEMANDS. WILL DEMONSTRATE RESTORED EDG l'
PERFORMANCE BY CONDUCTING SEVEN:(7) CONSECUTIVE FAILURE FREE START THIS FORM OF ACCELERATED TESTING SHALL BE CONDUCTED AT A FRE RUN TESTS.
OF NO LESS THAN 24 HOURS AND OF NO MORE THAN SEVEN (7) DAYS BETWEEN EA EACH UTILJTY WILL, IF APPLICABLE, ADDRESS THIS REDUCTION IN DEMAND..
ACCELERATED TESTING THROUGH CHANGES TO TECHNICAL SPECIFICATIONS OR OT APPROPRIATE MEANS.
i NOTE:
Boldf ace type represents additions to original Initiative 5 l
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4 ENCLosvRE A 5-39-90 REsPoh3BS TO CRGR COMMENTS 1:
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-(REF. CRCR MEETING N0. 176)
Following discussions related to guidance provided n NUMARC's revised Appendia'D (Enclosure F to the Comment is i
and Regulatory Guide 1.9, transmittal memorandus) f (Enclosure 3 to the transmittal memorandua),
Rev 3 the Cons'+'as reached a consensus that NUMARC's stovided soceptable guidance for Append l monitoriLy EDG reliability and an 3DG' reliability program, provided that licensees committed to implementing such a program and monitoring
.L Appendix D oculd be adopted by l
procedures.
reference in the regulatory guide (as an industry standard)... Regulatory Positions C.3, C.4, C.5 and C.6 would be reduced in size through reference to
. Appendix.D.
The RE8 staff tentatively agreed, subject to the u
understanding that a thorough review of the Appendix D would be needed to verify thy acceptability of Appendix D:ss formally submitted.
Final determination of the contents of the regulatory guide, generio letter, and Federal j
Register Notice would then be made.-
NUMARC's revised: Appendix D does not have the scope and informational content discussed at CRGR
' Response: '
Appendix D-(5-2-90) deals with Neeting No. 126.
monitoring EDG reliability.and corrective actions to^be taken if trigger values are exceeded, with only=brief aantion to.an EDG reliability-program.
Guidance for-activities associated with an EDG-reliability _ program-are now in a Topical Report-which-was not submitted by 4UMARC; nor does NUMARC intend to submit this report.-
NUMARC's submittal (see Enclosure F) has been p
reviewed by the staff and modifications:have been ande to Revision 3 of Regulatory Guide 1.9 as Because of:the appropriate, per CRGR direction.(4-6-90), an ndoption reduced scope of Appendix D t
by reference (in total) is not supportable.
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.1 Comment St~
'The consensusLdiscussed in Item-1 above was L
subject to:the condition that NUMARC agree with the approach, adopt the draft standard as-a final standard and make the final standard available to the publio.
i Responses copies of NUMARC-8700, Revision 1, &ppendia D can be obtained from NUMARC and such notification is included in Revision 3 of Regulatory Guide 1.9.
l Adoption by reference as a standard (such as IEEE 8td 387-1984) is not supportable for the reason noted above.
Comment 3:
The Committee reached a consensus that the generio letter transmitting the guide would not need to cite 10 CFR 50.54f if NUMARC would get industry agreement and have licensees submit letters committing to the industry standard.
It was agreed that WRR would contact NUMARC to initiate-pursuit of this approach.
If the commitments were
.not forthcoming the generic letter should cite 10 CFR 50.54f.
NUMARC's submittal encourages, but does not commit Responses utilities to comply with initiative-5A and Appendia D.
Therefore, the generio letter cites 10 CFR 50.54f and requests a statement of' intent I
to implement Initiative 5A and utilisation of guidelines provided in Appendix D, or identification of alterative methods to be' q
i employed (see Enclosure C).
Comment 4:
The CRGR considered issuance of the regulatory guide to be a backfit,-(regardless of-whether or-not licensees committed to.the industry standard as discussed in item 3 above) since issuance of the guide would apply a new staff position to operating plants.
Response
The staff agrees with this CRGR point of view and a backfit analysis based on NUMARC's submittal is enclosed (see Enclosure D).
Comment 5:
With regard to backfitting,-it was recognised that the conclusions on substantial safety improvement and cost justification had.been made for the overall generic issue in connection withLissuance of the blackout rule.
This regulatory guide revision was considered a necessary final step although additional explanation for this action was needed.
The backfit discussion in the proposed generic letter and the proposed backfit
p j
3 analysis should.be revised sooordingly.
The issuance of the station Blackout Rule'in.
Responses 53FR23217. June 21, 1988,- identified that GsI R-55 was an outstanding safety issue related to USI A-44 and that resolution of Ost-54 would provide specific guidance for use by the staff and industrycto review the adequacy of diesel generator reliability programs.
The backfit-analysis has been revised to more: clearly reflect this relationship to USI A-44, and it also notes 1
the applicability of A-44 conclusions to this q
regulatory guide revision. The 1-44 analysis-was i
based upon oosts and benefits / values associated with actions to be implemented through activities such as described NUMARC's Appendia D (5-2-90) and I
Regulatory Guide 1.9, Revision 3. Therefore, no separate-backfit analysis needs to be done.
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Comment 6:
The CRGR indicated that it would review-the revised regulatory guide at a future = meeting and would at least circulate the revised generio
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letter to the members.
Further, it would review d
I:
the basis for the action (backfit discussion and-backfit analysis) at a future meeting.,
j Enclosures'B, C, D,-E, and F are provided to 1
Response
facilitate CRGR review of the principal documents related to the resolution of G8: B-55.
l Comment 7 '
It was noted that the industry standard was_more detailed than normal regulatory guidance,- and NRC L
inspectors shcald'not focus on the finer details p
in the standard.
It was agreed that NRR-should' q
l-provided appropriate' guidance to the inspectors for this area in accordance with normal l
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procedures.
Since NUMARC has noted that the Appendia D Topical l
L Responses Report is not to be'used for.on-site inspections, L
Revision 3 of Regulatory Guide 1.9 has-retained f'
the general gttidance on EDG reliability program activities, but with modification through suitable reference.to guidance provided in NUMARC's
[1 Appendix D.
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L Comment 3:
On page'9 the proposed guide, footnote 3 should be removed and-reference to INPO should be removed'
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oI from footnote 2.
L References to INPO hevs been removed.
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Response
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i RMCWSURR_B Revision 3 i
6/14/90 Working Draft REGULATORY. GUIDE 1.9 (TASK RS 802-5)
SELECTION, DESIGN, QUALIFICATION, TESTING, AND RELIABILITY OF EMERGENCY DIESEL GENERATOR. UNITS USED AS CIASS 1E ONSITE ELECTRIC POWER SYSTEMS AT NUCLEAR POWER PLANTS A.
INTRODUCTION.
Criterion 1*1,t " Electric Power Systems," of Appendix.A,-
" General Design Criteria for Nuc. ear Power Plants," to-10 CFR i
" Domestic Licensing of Production and Utilisation Part 50, Facilities'," requires that onsite electric power systems have sufficient independence, capacity, capability, redundancy, and.
testability to ensure that (1) specified_ acceptable fuel design
-limits and design conditions of the reactor coolant pressure boundary are not exceeded as a' result of anticipated operational the core is cooled and-containment integrity occurrences and--(2) andiother' vital functions are maintained in the event of-postulated accidents, assuming a single failure.
t Criterion 18,. "I,nspection and Testing of Electric Power Systams," of' Appendix A to'10.CFR 50 requires.that electric power systems important to safety be designed to permit appropriate periodic inspection and testing to assess the continuity of the systems.and.the condition of their components.
Criterion XI, " Test Control," of Appendix B,
" Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants," to 10 CFR 50 requires that (1) measures be provided for verifying or checking the' adequacy of design by design reviews, by the use of alternative or simplified calculational methods, or
- a. test by the performance of a suitable testing program and (2) program be established to ensure that systems and components perform satisfactorily and that the test program include operational tests during nuclear power plant operation.
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" Loss of All Alternating Current power," of Section 50.63,
- 10 CFR~Part 50 requires that each light-water-cooled nuclear power plant be able'to withstand and recover from a_stationL ncy.ac power
. blackout (i.e.,. loss of offsite-and onsite emerge
~The reliability of onsite fbr a specified duration.
r system) factors
-emergency ac power sources is one of the maincontrib L
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blackout.
Diesel generator units have been widely used as the powerquintory guid This e source for onsite electric power systems.to the NRC staff for.,aplying with
_provides guidance acceptable the Commission't requirements that diesel generator units i
intended for-use as onsite emergency power sources in nuclear id power plants be selected with sufficient capacity,.be qualif e,
and be maintained to ensure availability of the r i
blackout and design basis accidents.
This guide has been prepared for the resolution of Generic d is related
_" Diesel Generator Reliability,".an" Station Blackout."
The Safety Issue B-56, (USI) A-44, diesel to Unresolved Safety Issue resolution-of USI A-44 established a need for an emergen (EDG) i bility achieve and maintain the emergency diesel gen generator station blackout.
This guide recognizes that unless emergency diesel form generators are properly maintained, their capabilities to per t be j
on demand may degrade. The condition of the diesel units mus J
riate monitored during test and maintenance programs, and approp r:
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3 parametric trends must be noted to detect potential fai ures d
appropriate preventive maintenance should be performe.
Guides 1.9 and 1.108 are considered to be in il a licensee revises plant technical specifications.
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' insert for ACRS approval will be added later]
C information collection activities mentioned in this regulatory guide are contained as requirements in 10 CFR Ae.f ide.
The Pa 3 50, which provides the regulatory basis for this gu Part 50 have been i
rmation collection req 2iraments in 10 CFR 3150-0011.
in clai red under OMB Clearance No.
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DISCUSSION An amergency diesel generator unit selected for use in an onsite electric power system should have the capability to (1)-
start and accelerate a number of large motor loads in rapid succession while maintaining voltage and frequency withinpr (2) acceptable limits, safety features if a loss of offsite power and an ac during the-same time period, and (3) the equipment needed to maintain the plant in a safe condition if an extended loss of offsite power occurs.
387-1984,* "IEEE Standard criteria for Diesel-Generator Units Applied as Standby Power Supplies for Nuclear IEEE Std Power Generating Stations," delineates principal design criteria if followed, will and qualification and testing guidelines that, help ensure was endorsed by Revision 2 of 387-1977 requirements.
(IEEE Std" Selection, Design, and Qualification of Regulatory Guide 1.9, (Onsite) Electric Power Diesel-Generator Units Used as Standby IEEE Std 387-1984 was Systems at Nuclear Power Plants.")
L developed by Working Group 4.2C of the Nuclear. Power Engineering of the Institute of Electrical and Electronics approved by NPEC,-and subsequently Committee (NPEC) 1982, std 387-Engineers, Inc. (IEEE),
approved by the IEEE Standards Board on March 11,IEEE Standard 308-1974, 1984 is supplementary to IEEE StdCriteria for Class 1E Power
" Standby Stations," and specifically amplifies paragraph 5.2.4, Power Supp3ies," of IEEE Std 308 with respect to the application IEEE Std 308-1974 is endorsed, with of diesel generator units.
certain exceptions, by-Regulatory Guide 1.32, "
also references other standards that Those referenced standards not IEEE Std 387-1984 contain valuable information.
endorsed by a regulatory guide or incorporated into theare to regulations, if used, current regulations.
I i
l and 2 copies may be obtained from the Institute of Electr ca 445 Boss Lane, IEEE Service Center,
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Electronics Engineers,Piscataway, NJ 08855.
Inc.,
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Box 1331, 3
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.e-A knowledge-of the characteristics of each load is essential
'in establishing the bases for the selection of an emergency diesel generator unit that is able to accept large loads in rapid-succession.
The majority of the emergency loads,are large This type of motor draws,.at full voltage, a induction-motors.
The starting turrent five to eight times its rated load current..
sudden large increases in'eurrent drawn from the diesel generator resulting from the startup of induction motors can result in The lower voltage could prevent substantial voltage reductions. accelerating its load to rated speed a motor from starting, i.e.,
in the required time, or could cause a running motor to coast Other loads might be lost because of low voltage.
down or stall.
if their contractors drop out.
Recovery from the transient caused by, starting large motors or from the loss of a large load if excessive, might could cause diesel engine overspeed that, g
J result in a trip of the engine, i.e.,
loss of the Class 1E power These same-consequences can also result from the cumulative effect of a. sequence of more moderate transients if source.
tha system is not permitted to recover sufficiently between.
successive steps in a loading sequence.
Generally.it has been industry practice to specify a maximum voltage reduction of 10 to 15 percent when starting large motors from large-capacity power systems and a voltage reduction of 20 to 30 percent when starting these motors from limited-capacity power sources such as diesel generator units. Large induction motors can achieve rated speed in less than 5 seconds when powered from adequately sized emergency diesel generator units that are capable of restoring the bus voltage to 90 percent of nominal in about 1 second.
Protection of the emergency diesel generator unit from excessive overspeed, which can. result from an improperly adjusted control system or governor failure, is afforded by the immediate operation of a diesel generator unit trip, usually set at 115 t
Similarly, in order to prevent percent of nominal speed. substantial damage to the generator, the ge current trip must operate immediately upon occurrence of an There are other protective trips provided to L.
internal fault.
protect the emergency diesel generator units from possiblethe damage.
- However, i.e.,
during functioning of the unit when it is most needed, Experience has sh accident. conditions.
numerous occasions when these trips have needlessly shut down emergency diesel generator units because of spurious operation of i
it is important that measures be I
a trip circuit.
Consequently, taken to ensure that spurious actuation of these other protective f
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trips.does not prevent the emergency diesel generator unit from 7 performing its function.
The uncertainties' inherent in estimates of safety loads at the construction permit stage of design are sometimes of such magnitude >that it is prudent to provide a substantial margin in selecting the load capabilities of the emergency diesel generator JThis margin can be provided by estimating the loads-unit.
conservatively and' selecting the continuous rating of the emergency diesel generator unit that exceeds the sum of the loads A more accurate estimate of safety _ loads needed at any one time.
because is possible during the-operating license stage of review, detailed designs have been completed and component test and preoperational. test data are usually available.
The reliability of diesel generators is one of the main-factors affecting the risk of core damage from a station blackout attaining and maintaining high reliability of event. -Thus, emergency diesel generators at nuclear power plants is necessary In Regulatory f o reduce the probability of station blackout." Station Blackout," the reliab t
Guide 1.155, generator is one of the factors to be used to determine the should be able to cope with a station length of time a plant blackout.
If'all other factors (redundancy of emergency diesel
)
generators, frequency. of loss of off site power, and probable time
^
needed to restore offsite power) remain constant, a higher reliability of'the diesel generators will result in a 4 ewer.
1 with a probability. of a total loss of ac power (station blackout) corresponding coping duration for certain plants according to j
' Regulatory Guide-1.155.
J High reliability should be designed into the emergency diesel generator units and maintained throughout their service This can be achieved by appropriate testing, and institution of a reliability lifetime.
maintenance, operating programs, and maintain reliability at program designed to monitor, improve, selected levels.
This guide provides explicit guidance in the areas of reporting requirements, preoperational testing, periodic testing,The preoperational and periodic and valid demands and failures.
testing provisions set forth in this guide provide a basis for taking corrective actions needed to maintain high inservice i
The data reliability of installed diesel generator units.
developed will provide an ongoing demonstration of performance 5
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1 and reliability for all emergency diesel' generator units after installation and'during service.
This revision.of Regulatory Guide 1.9 integrates into a.
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j single regulatory guido pertinent guidance previously addressed in Revision 2 of Regulatory. Guide 1.9, Regulatory Guida'1.108, i
and Generic Getter 84-15,-and it references, as_ appropriate,In addition,~this 387-1984.
guidelines set forth in.IEEE Stdguide describes s'aeans for me This. guide also reliability goals in-Regulatory Guide 1.155.
provides guidance for sa emergency diesel gener avels.
new Standard Technical Specifications (STS) 2n addition, are being developed by NRC and industry'as a joint effort. The J
periodic. testing guidance provided herein reflects. progress made to date to define'EDG surveillance requirements in the new STS.
~
those new STS surveillance. requirements Upon NRC endorsement, will supersede guidance on periodic testing provided in this i
regulatory guide.
l concurrent with the development of this regulatory guide, the Nuclear Management and Resources Council (NUMARC) has revised
" Guidelines and Technical Bases for NUMkRC Initiatives Addressing Station Blackout'at Light Nater Reactors."
WUMARC-87-00, "EDG: Reliability Program,"
NUMARC-8700, Revision 1, Appendix D,provides for monitoring-nucle J
which (4-6-90) reliability levels-and remedial actions to restore EDG reliability to above those values selected for station blackout.
j The NRC staff has reviewed NUMARC's. revised Appendix D and finds it acceptable for_ monitoring,and maintaining EDG reliability levels.: Table 1 of this regulatory guide provides a cro
~
i 8700, Revision 1, Appendix D.
C.
REGULATORY POSITION Conformance with the guidelines in IEEE Std 387-1984 "IEEE Standard Criteria for Diesel-Generator Units Applied as Standby Power Supplies for Nuclear Power Generating' Stations," is a method acceptable to the NRC staff for satisfying the Commission's regulations with respect to design, qualification, and periodic testing of diesel generator units used as onsite j
6
~
~
3 s.
< electric' power' systems for nuclear power plants subject to'the following:
DESIGN CONSIDERATI0HS-
- 1. -
387-1984'should be supplemented The guidelines of IEEE Std as follows:
should
" Inclusions," of IEEE 8td 387-1984 i
be' supplemented to include diesel generator auto controls, manual 1.1 -Section 1.2, controls, and diesel' generator output breaker.
1.2'. When-the characteristics of the required emergency diesel generator loads are not accurately known, such as during each emergency diesel the construction permit stage of design, generator unit of an onsite power supply system should be i
. selected to have a continuous load rating (as defined'in Sect on equal to or greater than the sum of 3.7.1 of IEEE Std 387-1984).
the conservatively estimated loads (nameplate)- needed to be.
In the absence of fully powered by that unit at any one time.
substantiated performance characteristics for mechanicalsuc equipment be calculated using conservative estimates of these e.g., pump runout conditions and motor characteristics, or less and power factors of 85 efficiencies of 90 percent percent or lower.
the predicted 1.3. At the operating license stage of review, loads should not exceed the continuous rating (as defined inof the diese Section 3.7.2 of IEEE Std 387-1984)
Section 5.1.2, " Mechanical and Electrical to the 1.4.
387-1984 pertains, in part, capabilities," of IEEE std starting and load-accepting capabilities of the diesel generator In conformance with Section 5.1.2, each diesel generator unit should be capable of starting and accelerating to ratedall the nee unit.
in the required sequence, The diesel generator unit'
- speed, feature and emergency-shutdown loads.
design should be such that at no time during the. loading sequence should the frequency decrease to less than 95 percent of nominal nor' the voltage decrease to less than 75 percent of nominal. (a larger decrease in voltage and frequency may be justified for a diesel generator unit that carries only one large connected Frequency should be restored to within 2 percent of nominal in less than 60 percent of each load-sequence interval load).
for step-load increase and in less than 80 percent of each load-sequence interval for disconnection of the single largest load, and voltage should be restored to within 10 percent of nominal 7
i
(A within 60 percent of each load-sequence time interval.be used if it can be
. greater porcentage of the time interval mayHowever; the load-sequence time in justified by analysis.
i
'should include sufficient margin to account for the accuracy and During recovery from repeatability-of the load-sequence timer).
transienta caused by the disconnection of the largest single.
-load, the speed of the diesel generator unit should not exceed the nominal speed plus 75 percent of the difference betw Furthermore, the transient nominal, whichever is lower.
f
-following the complete loss of load should not cause the speed o
-the unit to attain the overspeed trip setpoint.
1.5. Emergency diessi. generator units should be designed to The design is testable as discussed in Regulatory Position C.2.
should include provisions so that testing of the units will-(manual start, automatic simulate.the parameters of operationload. shedding, operation time, etc.),,
st a rt,' load sequencing, normal standby conditions, and environments (temperatttre,
humidity, etc.)~that would be expected if actual demand were be placed on the system.
lube oil and jacket water cooling at certain temperatures or prelubrication systems or both are normally in operation, this
-would constitute normal standby conditions for that. plant.
The units should be designed to automatically transfer from the test mode to an emergency mode upon receipt of 1.5.1.
emergency signals.
1,6. Design provisions should include.the capability to test each' emergency' diesel generator unit independently of the independence between redundant diesel generator units or between redundant units.
diese1 generator load groups,
~
Testability should be considered in the selection and location of instrumentation sensors and critical components 1.6.1 sensors should be readily accessible and designed so that their (e. g., governor, The overall inspection and calibration can be verified in place.
design should include status indication and alarm features.
" Surveillance Systems," of IEEE Std Section 5.5.3.1, pertains to status indication of diesel generat 1.7 387-1984 conditions.
as follows:
J B
l
3 g
surveillanco-system should be provided with remote
~
-1.7.1 A indication in the control room for displaying emergency diesel 1
i.e.,-under test, ready-standby, lookout.
generator unit status, A seans of communication should also be provided between diesel generator unit testing locations and the main control room to under test.
1.7.2 In order to facilitate trouble diagnosis, the diesel-
. surveillance system should indicate which of the emergency generator protective trips has been activated first.
1.8'Section 5.5.4, " Protection," of IEEE Std 387-1984,- which pertains to bypassing emergency diesel generator protective trips
~
should be interpreted as follows:
'during emergency conditions, The emergency diesel generator unit should be automatically
)
low oil pressure, and generator-tripped on an engine'overspeed,All other diesel generator protective differential overcurrent, trips should be handled in one of two ways: (1) a trip should be implemented with two or more measurements for.each trip parameter l
with coincident logic provisions for trip actuation, or (2) a conditions provided the trip _may be bypassed under accident operator has sufficient time to react appropriately to an.The design of the abnormal' diesel generator unit condition.
testing bypass circuitry should include the capability for (1)
(2) alarming the status and operability of the bypass circuits, in the control-room for abnormal values.of all bypass parameters and (3) manually resetting (common trouble alarms may be used), Capability for automatic reset is not the trip bypass function.
acceptable.
Section 5. 5.4 (2)- of IEEE Std 387-1984, on retaining all protective devices during. emergency diesel generator testing,
'does not apply-to a periodic test that demonstrates diesel j
generator system response under simulated accident conditions per and C.2.2.12.
Regulatory Positions C.2.2.5, C.2.2.6, l
9 i
I DIESEL GENERATOR' TESTING.
2.
Section 3, " Definitions," Section 6, " Testing,"' and Section 387-1984 should be
" Qualification Requirements,"'in-IEEE Std 7,
supplemented as discussed below.
I 2.1 Definitions The following definitions
- are. applicable to the positions of this regulatory guide that address testing, reliability recordkeeping, and reporting-of performance.
calculations, All valid and inadvertent start demands, Start demands:'
including all start-only demands and all start demands that are followed by load-run demands, whether by automatic or manual A start-only demand is a demand in which the emergency generator is started, but no attempt is made to load initiation.
See " Exceptions" below.
the emergency diesel generator.
Any failure within the emergency generator
-Start failure 2:
system that prevents the generator from achieving (For the monthly surveillance tests, the emergency.
diesel generator can be brought to rated speed and voltage in a
~
failure.
time that is recommended:by the manufacturer to minimise stre
/
and wear.
Similarly, and voltage in the precise time _ required by technical if
-specifications,-the start-attempt is not considere an emergency).. See " Exceptions" below.
in the course of maintenance inspections.(with the EDG in the standby mode) that would' definitely-have.resulted,in a start E
lid failure.if a demand had occurred should be counted as a va J
start demand and failure.
t
' Additional useful information on testing and test definitions can be found in. the ASME O&M Part 16,
" Inservice -Testing and-Copies can Maintenance of Diesel Drives-at Nuclear Power Plants."of Nec be obtained by contacting the American Society L
Engineers (ASME), United Engineering Center, 345 East 47th Stre New York, NY 10017.
- These definitions are taken from NUMARC-8700, P.r vision 1,
[
Appendix D, May 2, 1990.
10 o
m.
1
.=
Load-run demands: To be valid,: the load-run attempt must i
'ollow a successful start: and uset one of the following criter a:.
-(see "Esceptions" below.)'
lts~from a eA load-run of anyJduration that resu l
real (e.g., not a test) automatic or manual o
)
- signal, A load-run test:to satisfy:the-plant's load and' o-duration test specifications.
(e.g., special tests) in which 1
other optrations the emergency diesel generator is planned to runene houjl o
for at least design load.
Load-run Failures t A load-run failurs 'should.be counte 1
the amargency-diesel generator starts but does not pic
~
and run successfully.See " Exceptions" below.
(For monthly d-surveillance tests, the emergency diesel generator can be loade should be counted.
at a rate that is recommended by the manufacturer to min h
load-
,the preciseLtime required by technical specificatio stress and wear.
td-Any
'that_the generator would load and run in an em i
(with the EDG in the standby mode) -
h ld be resulted in'a load-run' failure if'a demand had occurredos counted' as a valid load-run demand and failure, Unsuccessful attempts to. start ~or load-run should not be counted as valid demands or failures.when they.can-Exceptions:
e be' definitely attributed to any of the following:
Spu.tous operation of a trip that would be bypassed in the emergency operation mode (e.g.
I o
L hi;i cooling water temperature trip) t required to
. Malfunction of ' equipment that is no h
operate during the emergency operating mode (e.g.,
)
o synchronizing circuitry).
Intertional termination of the test because of
,L (e.g.,
alarmed or observed abnormal conditionsthat would h
o small water or oil leaks) s t
l 11
go
- b ultik 613 resulted in significant emergency t
t
~
Lgenerutor damage or failure, Component malfunctions or operating errors that did not prevent the emergency diesel generator.
o.
> from being restarted:and brought to load within a l
few minutes i.e., without corrective maintenance j
or significant' problem diagnosis),
q A failure to start because a portion of the H
starting system wasLdisabled for test purposes, if o
followed by a successful start with the starting.
system in its normal alignment.
Each emergency diesel generator failure that results.in.the emergency diesel generator being declared. inoperable should bel counted as one demand'and one failure.
l
< corrective maintenance and the successful test that is-run l
following repair to verify operability should not b d
again.
1 L
2.2
_ Test Descriptions 4
The following test descriptions are to be used withTable 2 describ Regulatory Positions C.3 and C.4.
There should be of< qualification and surveillance testing.
detailed' procedures for each test defined in Regulatory Position l
L The procedures should identify special-arrangements or t
j changes in normal system configuration'that must be m 10. 2. 2..
t to initial the EDG'under test.
or' arrangements should not be used subsequen 1
L equipmentLstartup. testing.
-l gj Demonstrate proper'startup from j
and ' verify that the required design voltag 2.2.1, Slow-Start Test:
(
standby conditions, ed j
and frequency'is attained.
generator can be slow-started, he'prelubricated, have prewarm j
h d
a oil and water circulating, and should reach ~ rated spee on
~
d wear.
l b
prescribed schedule that is select'ed to minimize stress an R
1 Demonstrate 95 to 100 percent of:
i:
2.2.2 Slow' Load-Run Test:
for an interval of not less s
the continuous rating of the EDG,than l' hour and until tem t i ed, P
[
.This test may be accomplished by synchron zoffsite p diesel l
p H
I 12 I
l A
generator during this test should be gradual and base y
on the diesel-generator.
Demonstrate that each-2.2.3 Fast-Start and Load Test:
emergency. diesel generator unit starts from standby conditions (if a plant has normally operating prelube and keep-warm systems, this would constitute its standby conditions),and verify that the 4
emergency diesel generator reaches standby required voltage and frequency within acceptable limits and time as defined in the ant technical specifications,
}
2.2.4 Loss-of-Offsite-Power (LOOP) Test:
Demonstrate by (1).the emergency buses simulating a loss of offsite power that are doenergized_and the loads are stad from the emerg attains the required voltage and (2) signal from its standby conditions, l
and frequency and energizes permanently connected loads w acceptable limits and time, and operates for a minimum of 5 loads through the load sequencer, minutes.
Demonstrate that on a safety initiation 2.2.5 SIAS Test:
the emergency diesel generator starts on actuation signal (SIAS),
the auto-start signal from its standby conditions, and operates on standby for' greater than or equel'to 5 minutes.
Demonstrate that the 2.2.6 Combined SIAS and LOOP Tests:
EDG can satisfactorily. respond to a loss of offsite power (LOOP) in conjunction with-SIAS in whatever sequence they might occur A
(e.g. LOCA followed by_ delayed LOOP or LOOP'followed by LOCA simultaneous LOOP /LOCA event would be demonstrated by simulati (1) the, emergency buses are a LOOP and SIAS an verifying that deenergized and loads are shed from-the emergency buses and (2) the emergency diesel-generator starts on the auto-start signal from its standby conditions, attains the required voltage and frequency and energizes permanently connected loads with acceptable limits and time, h the through the load sequencer, and operates while loaded wit auto-connected loads for greater than or equal to 5 minutes, Demonstrate the emergency 2.2.7 Sinale-Load Reiection Test:
diesel generator's capability to reject a loss of the largest i
q single load and verify that the voltage and frequenc l'
13 a.
Demonstrate the emergency 2.2.8 Full-Load Reiection Test:
diesel generator's capability to _ reject a load equal to 95 to-100 percent of it's continuous rating and verify that the voltage requirements are met and that the unit will not trip on overspeed.
Demonstrate full-load 2.2.9 Endurance and Marain Test:
carrying. capability for an interval-of not.less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, of which 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> should be at a load equal to :105 to 110 percent of the continuous rating of the emergency diesel generator, and 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> at a load equal to 95 to 100 percent of it's continuous i
Verify that voltage and frequency requirements are rating.
maintained.
Demonstrate hot restart 2.2.10 Hot Restart Test:
= functional capability at full-load temperature conditions attains the required voltage and frequency or auto-start signal, and operates for longer than 5 within acceptable limits and time, minutes.
Demonstrate the ability to (1) 2.2.11 Synchronizina Test:
power while the unit is connected to the emergency (2) restore the EDG transfer this load to the offsite power, and (3) to ready-to-load status.
Demonstrate that all 2.2.12 Protective-Trio Bypass Test:
automatic emergency diesel generator trips (except engine and generator differential) are automatically bypassed upon a safety injection actuation signal.
overspeed, oil pressure, This test may be performed in conjunction with Regulatory Position 2.2.6.
Demonstrate that with 2.2.13 Test Mode Chance-over Test:
the emergency diesel generator operating in the automatic test a simulated safety injection mode while connected to its bus, returning the emergency signal ~ overrides the test mode by (1) diesel generator to standb automatically energizing the emergency loads from offsite power.
Demonstrate that, by starting 2.2.14 Redundant Unit Test:
and running both redundant units simultaneously, potential common failure modes that may be undetected in single emergency diesel generator unit tests do not occur.
14
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7 I
8.:
Pre-Operational and-Surveillance Testina 2.3 Table 2 relates pre-operational and surveillance tests to the anticipated schedule for performance (e.g., pre-operational,
[*
scheduled refueling period, and g,
monthly surveillance, 6-month, 10-year testing).
All planned tests should be proceeded by a prelube period and should be in general accordance with the manufacture's g
including cool-down recommendations for reducing engine wear, i
- operation at reduced power followed by postoperation lubricat on.
2.3.1 Pre-Operational Testino:
A pre-operational test program should be implemented for all emergency diesel generator This systems following assembly and installation at the site.
program should include the tests identified in Table 2, and the tests described in Regulatory Position C.2.2 should be carried out.
In addition, demonstrate through a minimum of 25 valid start-and-failure on each installed load demands-(or tests) without amargency diesel generator unit that an acceptable level of reliability has been achieved to place the new EDG inte nn operational category.
After the plants are licensed 2.3,2 Surveillance Testino:
(after fuel load), periodic surveillance testing of each amargency diesel generator must demonstrate continued capability and reliability of the diesel generator u..it to perform its l
When the EDG is declared operational in intended function.
accordance with plant technical specifications, the following periodic test program should be implemented.
2.3.2.1 Monthlv Testino:
After completion of the emergency diesel generator unit reliability demonstration during preoperational testing, periodic testing of diesel emergency generator units during normal plant operation should beEach. d performed. described in Regulatory Positions C.2.2.1 or C.2.2.3 and loaded as described in 2.2.2 at least once in 31 days (with maxim 1
interval).
15
4
~ '.
2.3.2.2-Six-Month (or 184 days) Testino:'- In order to
' demonstrate the capability of the EDG to start from standby and provide.the necessary power to mitigate the loss-of-ooolant accident coincident with loss of offsite power, once every 6 months each diesel generator should be_ started from standby conditions as described in C.2.2.3 to verify that the diesel generator reaches stable rated voltage and frequency within t technical
, acceptable limits and time as specified in the plan Following this test the EDG should be loaded as specifications.
described in Reg. Position C.2.2.2.
.(See also Table 2).
overall emergency 2.3.2.3.
Refuelino Outaae Testino:
diesel generator unit design capability should be demonstrated at every refueling outaca by performing the touts identified in Table 2.
2.3.2.4.
Ten-Year Testino:
Demonstrate that the trains of standby electric power are independent.once e that could affect emergency diesel generator independence, 10 years whichever is the shorter, by starting all redundant u undetected in single diesel generator unit tests.
If an individual EDG 2.3,3 garrective-Action Testino:
experiences-4 or more failures in the last 25 demands, then following completion of corrective actions perfor f
the problem _EDG must be demonstrated by conducting seven j
consecutive failure. free start and load-run dem y
i between each demand). All starts and load-run i
j so long as the EDG is declared operable, reliability data set l
'EDG RELIABILITY GOALS AND MONITORING l
3.
Reliability goals for emergency diesel generators and their
[
monitoring are as follows:
Reliability Goals for Station Blackout 3.1
" Loss of All In order to comply with 10 CTR 50.63, i
This test may be substituted for a monthly test, i
16 l
l u
1 ',
idance in Regulatory Guide
- Alternating current Power,." and the gu" Station Blackout," the minimum targeted at 0.95 or 0.975 per demand for each EDO for plants inand 1.155, h
emergency ac'(EAC) Groups A, E,
each EDG for plants in EAC Group D (see Table 2 of Regulatory L
Guide 1.165),
EDGs credited to each nuclear unit's station blackout coping i:
assessment should be monitored and maintained a EDG Reliability Monito,Iing 3.2 The monitoring of EDG reliability should be based on valid-demands, valid starts, and valid load-run tests as dsfined inand i
. Regulatory Position 2.1, The determination of adequate EDG Regulatory. Position 2.3. performance should be based on a relia 50, and 100 demands.
the performance data from the last 20, The calculation of the' performance and reliability indicators for individual EDGs comprises two components:the load-run relia the start reliability and ' (2) data not all EDG demands include both start and load-run demands, (1) on these two reliability components should be gathered and evaluated individually and then combined. An equ follows:
.These reliability components are defined as interval.
1)
Start Reliability (SR) is defined as:
SR = Number of Successful Starts Total. Number of Valid Start Demands is defined as:
s.
Load-run Reliability (LR) 2)
P LR = Numher of Successful Load-runs Total Number of Valid Load-Run Demands (LR)
(SR) 3)
EDG Reliability
=
The above equations produce point estimates of individual Care should be-EDG reliabilities with attendant uncertainties.
ih taken in using such numbers in comparing plant performance w t the EDG trigger values, particularly when using the last 20 3-demands data set.
e 4
17 i
-m
y Estimates of EDG reliability for a nuclear unit should combined utilise individual EDG performance data, which are then Lin a manner representative of the EDGs assigned to a specific
.NUMARC-8700, Revision 1, Appendia D, Table D.2-1, nuclear unit.
provides guidance for combining data from individual EDG-performanbe to arrive at a nuclear unit reliability estimate.
3.3 Maintainina RDG Reliability:
Maintaining EDG reliability should include the following:
maintaining data on successful and failed (1) -EDG start and load-run demands.
indicators evaluating nuclear unit reliability (2) for the last 50 and the last 100 demands as well as individual EDG performance over the last 20 demands.
relating calculated EDG performance and (3) reliability indicators to trigger values established for selected target reliabilities.
taking remedial actions for individual failures (4) and for exceeding one or more trigger values.
The sample size and action levels are based on the assumption that the minimum surveillance testing interval for each EDG is once per month.
The following failure rate triggers thould be used to assess EDG performance and to determine corrective actions to be taken:
EDG TRIGGER VALUES Selected Failures in Failures in Failures in Reliability 20 Demands 50 Demands 100 Demands Target 0.95 3
5 8
4 5
0.975 3
The selected target reliability is that selected for the station blackout coping analysis. This value represents the underlying nuclear unit EDG reliability needed for determining the coping duration for a station blackout. Figure 1 defines actions that 18 k
l.
should be undertaken as an integral part of an ongoing BDG l
A more detailed discussion of actions related to exceeding one or more of these triggers can be found in Section are exceeded.
D.2.4 of WUMARC's Appendix D.
3.4 Probles EDG A problem diesel generator is defined as an individual BDG that has experienced 4 or more failures in the isst 25 demands.
Should this case arise, the actions taken in response tn exceeding a single trigger value as defined in Figure 1 would p
(
apply.
Following completion of reliability program corrective actions, restored performance of the problem EDG should be demonstrated by conducting seven consecutive failure-free start and lead-run The monthly demand tests per Regulatory Position 2.3.3. schedule should not be resumed surveillance test All starts and consecutive tests are successfully completed.
load-runs performed during this period should be included in the nuclear unit EDG reliability data set so long as the EDG is declared operable.
This process of evaluating recent demands and taking key element in providing reasonable assurance that EDG performance is restored to an acceptable level.
RECORDKEEPING GUIDANCE' 4.
" Records and Analysis," of IEEE Guidance from Section 7.5.2, should be supplemented as follows:
Std 387-1984 Utilities should retain the following information from monthly surveillance tests related to the trigger values and remedial actions taken in response to exceeded trigger values:
Data on valid demands and, failures that are used to calculate the performance and reliability (1) indicators.
' Licensees should also retain data relevant to the fast start tests required by Technical Specifications.
19
l-The corrective actions taken in response to L
(2).
individual failures.
L A description of the actions taken in (3). response to exceeding a single trigger, u
L 3
A description of the EDG reliability program i
L (4).
improvements in response to exceeding the i
triggers for 50 and 100 demands, The schedule of planned and in-progress l
(5) improvements.
5.
REPORTING CRITERIA When reporting EDG failures, all plants should conform with 10 CFR 50.73, 10 CFR 21, plant the provisions of 10 CFR 50.72,and other current NRC reporting
-technical specif cations, i
i regulations.
- 6. EMERGENCY DIESEL GENERATOR RELI ABILITY PROGRAM!
NRC staff for meeting the requirements of 10 CF identifies the need for an EDG reliability. program designed to maintain and monitor EDG reliability levels to ensure that selected reliability levels are being achieved.
l l
Regulatory Guide 1.155 also provides brief ;uidance on typica j
elements or activities associated with an EDG reliability program.
l This section provides guidance for a reliability programIt is also rec l
i
. based on proven industry practices.
i t
there are other existing programs that have proven effect ve a idance j
maintaining high EDG reliability levels. Therefore, this gu is not intended to replace or supplement such programs.
The principal elementa of an EDG reliability program (or should encompass the following:
4 activities) l Monitorina nuclear unit EDG reliability j
levela against those selected for station j
1.
g (see also Regulatory Position C.3).
p blackout
.r 20
)
L k
a 1
ei t
b 1
4 A surveillance olan that identifies 200 2.
support systems and subsystems, describes frequency and scope of testing, and incorporates L
manufacturer recommendations.
Performance sonitorina of important l
3.
parameters cnr an ongoing basis to obtain L
information on the condition of the RDG and key components so that precursor conditions l
can be identified prior to failure, i
A maintenance proaram designed for both 4.
preventive and corrective actions based en i
operating history and past maintenance activities, vendor recommendations, spare parts considerations, and the results of surveillance monitoring.
Failure analyses _and root cause investigation l
5.
to assist in developing corrective actions to.
prevent recurrence of failures.
An EDG problem closeout process to ensure 6.
that the resolution of a failure or a problem.
is properly implamented and successful.
An EDG reliability data system to ensure the 7.
availability and retrievability of important data and information related to EDG reliability.
These principal elements of=an EDG reliability program areOth provided'as guidelines.
such as the TDI the same or similar activities may also La used, Owner's Group maintenance and surveillance activities.'
Such programs should be revidwed for consistency with Regulatory Guide 1.155 and this regulatory guide.
" Design Review / Quality Validation"
' Revision 2, Appendix 2, report submitted 5/1/86, J.
George (TDI) to H.
Denton- (NRC) was utilised in revising plant-specific technical specifications.
21
-s--,,
Monitorina Diesel Generator Reliability
~6.1 Monitoring of nuclear unit EDG reliability should be based on periodic surveillance testing as discussed in Regulatory Position *C.3 and corrective actions undertaken when one or more triggers are exceeded.The reliability program should provide the means for failu p).
corrective action, and demonstration of its evaluation, effectiveness.
6.2 EDG Surveillance Plan A surveillance plan should consider the following factors:
The effect that EDG support and auxiliary 1.
systems have on overall EDG reliability.
2.
Failures caused by surveillance.
Frequency and nature of surveillance testing 3.
effects on EDG reliability and unavailability.
The types of failures that can be detected by a 4.
surveillance program.
Detection of failures by parameter monitoring 5.
versus testing.
The ability of specialized tests to simulate 6.
actual operating conditions.
Figure 2 illustrates typical components and support systems L
that;should be considered when defining an EDG boundary. Those components whose function is solely to support the EDG are to be i
viewed as within the EDG boundary. The systems that provide support to the EDG and perform other plant functions are shown l
outside the boundary, with the understanding that the boundary interface function must be maintained.
and ANSI /ASME OM-16 provide similar p
IEEE Std 387-1984 definitions of components and system boundaries and may also be p
used-as guidance.
Tables 3 and 4 list types of periodic surveillance l
activities that have proven effective. When' performing s surveillance, 22
i y
critical-parameters since such data would be extremely useful for failure analyses, as well for long-tern EDG condition sonitoring.
6.3 EDG Performance Monitorina Performance monitoring should be applied tu equipment that The purpose is is run on a continual or a near-continual basis.
to monitor certain parameters on an ongoing basis in order to l
obtain information about the state of physical conditions that may potentially impact the operability of a piece of equipment These trends may and that could be used for trending purposes.
Such evaluation signal a degradation in a particular condition. failure and allow corrective a may detect onset of taken before failure occurs.
such as Equipment that is normally in a standby condition, can only be monitored on a limited basis. Monitoring critical operating parameters is usually performed during monthly an EDG, i
operational testing. In order for this monitoring to be l
should be applied to the following conditions:
effective, it The characteristic or parameter should be a 1.
measurable condition that is known to be related to an important failure mode.
The characteristic or parameter should be 2.
able to be measured conveniently and practically.
The characteristic or parameter should be 3.
accurately monitored.
Parameters recorded should be measured under 4.
the same conditions (i.e., load) to the extent possible.
The actual values of the conditions should be recorded rather than simply verifying that they are-within a spec readings can then be made to ascertain the possibility of a range.
degrading condition.
6.4 EDG Maintenance Procram An important contributor to EDG reliability is the manner in which both preventive and corrective maintenance are performed.
23
.. - ~ _ _ _ _ _ _
g l:
Generally speaking, an EDG maintenance program-should be based on the followingi Vendor-recommended maintenance actions and 1.
- schedule for implementation.
Maintenance actions should be prioritised 2.
based on such factors as repair time, y
severity, likelihood of reoccurrence..
The reliability characteristics of the.EDG 3.
subsystems and components should be j
considered when planning RDG preventive maintenance.
i l
Maintenance activities should s eserface with i
4.
the overall EDG reliability program, The maintenance program should have both a preventive and a The preventive program should be tailored to Table 5 shows typical examples of preventive corrective element.
specific EDG types.
maintenance activities.
EDG Failure Analysis and Poot Cause Investication 6.5 Jm EDG reliability program should include failure analysis l
procedures designed to systematically reduce problems or failures Failure analysis starts from the most l
to corrective actions.
f underlying
-apparent symptoms and progresses to determination o causes or incipient conditions. Root cause analysis Figure.3 is an example of a j
operation, or maintenance.
systematic approach.to failure and root causefanalyses.
-l When performing a root cause analysis, the method of l
categorizing underlying causes is important so that A typical classification system should 1
reliability program.
consider the following:
Manufacturing and design a.
b.
Quality control 24
\\
5 L
j d.
Training-e.
Communication L
f.
Numan factors j:
l~
6.6 EDG Problem Closeout Attention should be given to procedures and controls used to The ensure the resolution or " closeout" of a particular problem, eloseout of a failure or problem that is detected during l
' maintenance or surveillance should be closed out by means of a formal procedure.
A formal plant-specific procedure offers a o
means to prevent recurrence of the particular failure or problem.
The problem closeout procedure should be based on the following considerations:
- 1. Criteria for closeout
- 2. Closecut review
- 3. Closecut monitoring 4, Data system interface A more detailed discussion of problem closeout considerations can be found in NUMARC's Appendix D Topical Report.
6.7 EDG-Reliability Data System An EDG reliability program should have a data collection, and retrieval system that can be accessed by personnel assigned to monitoring and maintaining the EDGs and satisfying
- storage, The data system does not need to be a Regulatory Position C.5.
but access to " current" special purpose dedicated system, information should be a major consideration.
Typical types of information that should be considered in the formation'of a data system are:
1.
Surveillance test results 2.
EDG failure history 25
+
Failure and root cause analysis rCsults 3.
Manufacturer's recommendations 1
4.
Input from the preventive maintenance program 5.
Input from the corrective maintenance program-6.
Industry operating experience 7.
D.
IMPLEMENTATION The purpose of this section is to provide information to applicants and licensees regarding the NRC staff's plans for using this regulatory guide.
Except in those cases in which an applicant proposes an ified acceptable alternative method for complying with the spec d
portions of the Commission's regulations, the m j
the NRC staff in evaluating selection, testing of diesel gene i
r-r l
systems-for the following nuclear power plants:
[
Plants for which the construction permit is l
issued after the issue date of the final 1.
l
- guide, Plants for which the operating license application is docketed 6 months or more 2.
after the issue date of the final guide, Plants for which the licensee commits to the 3.
l.
provisions of this guide.
~
3, C.4, The NRC Staff intends to use Regulatory Po i
of l'
- failures, EDG reliability levels, record keeping, reporting of C.5, F
and existing or proposed EDG reliability programs.
f ff Implementation of this regulatory guide by the NRC sta issuance).
l will in no case be earlier than (270_ days after l
lfk 26 I
i
--_--------,----__-_-_---_--a_
--w
-n wr-m--
REGULATORY AltALYsts A separate regulatory analysis was not prepared for this The regulatory analysis preparad for the
" Regulatory /Sackfit Analysis regulatory' guide.
station blackout rule, NUREG-1109,for the Resolution of Unreso Blackout," provides the regulatory basis for this guid A copy of NUREG-1109 is available for inspection and2120 L street guide.
copying for a fee at the NRC Public Document Room, Copies of NU NN., Nashington, DC.the Superintendent of Documents, U.S. Governm 20013-7802; or from'the Post office Box 37082, Nashington, DC Springfield, VA 22161.
National Technical Information Service, L
l L
i l
27 L
g
.j
!.[
~'
6-14-90 PRE-OPERATIORULL AND SURVEILIANCE(a) TESTING TABIE 2.
Refueling Refer ~to Monthly Outage 6-Month 18 Month 10-Year Regulatory Pre-Operational Periodic Tests Tests __
Position C.2.2 Tests
_Tes_ts_
Test Program i
for Description X
X (b) 2.2.1 Start Test-X X (b) 2.2.2 Load-Run Test X (c)
X(c)
X (c).
2.2.3 Fast-Start and Load Test X
2.2.4 Loss-of-Offsite Power ' (IOOP) Test X
X X
2.2.5 SIAS Test K
X 2.2.6 Combined SIAS & IOOP Test X
X 2.2.7 Single-Load Rejection Test X
X 2.2.8 Full-Load Rejection Test X
X 2.2.9 Endurance and Margin Test t
X X
2.2.10 Hot Re-start Test X
t X
2.2.11 Synchronizing Test X
2.2.12 Protective-Trip Bypass X
Test 2.2.13 Test Mode Change-Over x
Test X
X 2.2.14 Redundant Unit Test Tech Spec requirements take precedence to this table.
i 2.3.1.
Included in each of the 25 tests described in Regulatory Posit on (a)
Utilities should retain data for fast starts required by Tech Specs.
(b)
This test may be substituted for a monthly surveillance test.
(c)
{
i
h (6-14-90L TABLE I CROSS-REFERENCE BETWEEN REGULATORY GUIDE 1.9, REv. 3 AND NUMARC-87-00, APPENDIX D (3-8-90)'
RG 1.9,REV 3 APPENDIX D SECTION None- (Use RG 1.9,Rev.3)
Section A, Introduction None (Use RG 1. 9, Rev. 3)
Section B, Discussion Section'C, Regulatory Position None (Use RG 1. 9, Rev.3) 1 Design Considerations 2 Diesel Generator Testing D.1 2.1' Definitions None (Use RG 1. 9, Rev. 3)-
2.2 Test Descriptions 2.3 Preoperational and None (Use RG 1.9,Rev.3)
' Surveillance Testing D.2 3 EDG Reliability Goals and Monitoring Introduction 3.1 Reliability Goals for SBO D.2.3 3.2 EDG Reliability Monitoring D.2.1,D.2.3,D.2.4,D.2.5' 3.3 Maintaining EDG Reliability D.2.4.4 3.4 Problem EDG D.2.4.6 4 Record keeping Guidance Use RG 1.9, Rev. 3 5 Reporting Criteria Introduction J
None (Use RG 1. 9, Rev.3) 6.EDG Reliability Program 6.1 Monitoring EDG Reliability (Use RG 1.9,Rev.3)
None None (Use RG 1. 9, Rev.3) 6.2 EDG Surveillance Plan 6.3 EDG Performance Monitoring (Use RG 1.9,Rev.3)
None (Use RG 1.9,Rev.3) 6.4 EDG Maintenance Program None 6.5 EDG Failure Analysis and Root Cause. Investigation (Use RG 1.9,Rev.3)
None 6.6 EDG Problem Close-out None (Use RG 1.9,Rev.3)
(-
6.7 EDG Reliability Data System Introduction Section D, Implementation (Initiative 5A) y 28 r
~.
1
TABLE 3'. EDG SEIFT OR Dh!LY St5tVEILLhMCE (EXAlfLE)
Governor Sveten p % 011 avetam Governor oil level Lube oil splet temperature Verify load limit settings Lube oil outlet temperature Governor setting in Lube' oil sump level Auto / Manual Lube oil strainer / filter 1
differential pressure J
Visual inspection for leaks i
Riesel/ Generator 011 Level of pedestal bearing Fuel 011 System Turbo oil level j
Intercooler leak inspection l
Day tank level Turbocharger lube oil level Storage tank level Drain moisture from exhaust Bleed fuel oil filters silencers Visual inspection for leaks Verify alarus clear Bleed fuel oil filters
- Diesel starting selector 1
switches in remote EDG breaker remote-local select l
switch in remote l
Verify auto-manual regulators in normal range set Check water and fuel hoses packet Water System Check starter motors l
Check exhaust Jacket water inlet temperature Jacket water outlet temperature Expansion tank level Visual inspection for' leaks Electrical
- Startino Air System Auto / Manual start switch in auto Appropriate breakers racked inPower t Air receiver pressure Blowdown air receiver Compressor oil level operation of compressor traps source Aligned to appropriate power Fault Indir.ator i
- Weekly surveillance
~
a, I T
m TABLE 4A. MONTELY EDG SURVEILLANCE (EXAbSLE)
Governor systes Diesel / Generator Inspect linkage for looseness Visually inspect fuel system for leaks verify all control settings Visually inspect for exhaust leaks Check actuator oil level j
Drain water from crankcase vent piping Check automatic shutdown l
l Verify generator synchronization Filter DP l
Engine coolant level Inspect for leaks Mainfold pressure Day tank level i
Crankcase pressure Storage tank level Air inlet temperature Verify transfer pumps Turbo temperature Intercooler outlet temperature Fuel oil pressure operabilitj (inlet / outlet)
Ventilation fan operability Cylinder exhaust temperatures Cooling water supply tamperature L_ube 011 System Stator temperature Check lube oil for dilution Gen f requency Lube oil chemical analysis Gen voltage Inspect for leaks Gen Amps LO filter DP Gen KW Lo pressure LO level Turbo LO pressure Jacket Water System LO inlet temperature Inspect for leaks LO outlet temperature Check water treatment EX outlet tamperature Engine outlet temperature System pressure Turbo outlet temperature In addition to the above surveillances there are other less frequent inspections i
Examples of these include the following:
that may be considered.
(EXAMPLE)
TABLE 4B. LESS FREQUENT EDG SURVEILLANCES Periodic Surveillance:
once every quarter Lubrication oil Chemical Analysis once every quarter i
Fuel Oil Chemical Analysis L_
Non-Periodic Surveillances :
Upon delivery and prior to us-Chemical analysis of new fuel oil Upon delivery and prior to us-Chemical analysis:of new lubrication 011
=
TABLE 5 TYPICAL PREVENTIVE MkINTENANCE ACTIV Ennine Lube Oil System:
lube oil strainer Clean and inspect Replace lube oil filters Replace turbocharger filter element Inspect lube oil cooler
. 7 gy}gine Cooline System:
Inspect cooling water pump Drain and replace coolant "nspect expansion tank F_uel Oil System:_
Replace fuel oil filters Clean and inspect fuel oil strainers Test fuel condition r
Startine Air Systemi Clean and inspect air strainer
-Replace compressor oil compressor drive belts.
1 Inspect Encine Maintensnee:
air filter oil Replace inlet Inspect and clean inlet air filter Inspect air box drains air box cooling system Inspect Check cylinder head to piston clearances Inspect cylinder liners
' Inspect rod bearings j
Inspect main bearings Inspect piston rings-I 4
i.
l I
e -.--
d
~~
, Periodic Monthly 1 -
Testing 1
i Failures / Demands Unit Triager Values
- l Feliability
~~
No l
New 0.95 3/20 5/50 8/100 Failure 0.975 3/20 4/50 5/100 a
1 Yes i
1 r
- 1 Compare with I
Trigger values I
i l
1 1
I 1
Exceed 50 and 100 l
1 T
F Exceed One Demand Triggers Exceed No Trigger Triggers t
i 4
4 l
- 1. Root Cause l
I-
- 1. Root'Cause
- 1. Root Cause
- 2. Applicable Failures Applicable Failures
)
2.
- 2. Corrective Action
- 3. Maintenance Mistory
- 3. Maint' nance History 4.
$11ere Pattern
- 4. Failure Pattern ll
- 5. Fi% Eau Changes
- 5. Corrective Action
- 6. Corrective Action
[
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u
- ~ g j
1
~
i f
& Maintenance Activities i
Figure 1, Reliability Monitor ng-i l
t i
i
~~
Class IE AC Electric Distribution d
Power System 4
Emergency Diesel Generator System Doundary o....... o.
........e
,..o..
J g
T EDG
~~ e
.a.
,./ DnEAKER c
y f
Govemor and Enhaust 1
e lubrication Control System System l
,f
- Control and System l
l pro,,ction 6
{
j System o
i l -- l'l l
m Diesel Engine 2
Crar* case ventiiat%
h I
8 System Y
4 g
I n
o r
l e
l Venage i
JacketWater FuelOn l
Regulator Syssem l
l CooEng Air Contmstion and W System Starteg e
and venlaation Air System w,,,, 373,,,
System o
l System and Somy
...............................o......,
l I
I i
l r
g.-
FuelON f
coonngwater Storage and i
e Sumv System i
Suppy i
3
?
I 1
i___._.___.
i i
Figure 2 - Emergency Diesel rmr Systems, Boundary and Support Systems l
.l
_. _,. ;,,; m.,
.i C
Monitor EDG 4-Performance V
Failure or off normal 1
condition observed U
Prablem cloteout
~
Assessif Determine proximate cause surveillance or (tailure cause analysis),
performance monitoring p
should be offered Compare to past 1
Iallures / conditions Ik to indicate possible systematic cause No Systematic Cause r
System.'j: Cause U
Perform root i
cause analysis i
D If Generic Generic or Cause Review other plant plant specific-A generic 0
records (NPRDS),
industry groups, etc.
cause?
cure exists t Plant No Yes Spe:ifi0 U
Cause V i
Determine 11
%Pbent Review operational.
j operation or cure j
procedures, install design re ated special monitoring cause l
If required Operation Related Design Related Change cpt rations Redesign to to corrert problem correct probtem U
s y
Figure 3-Failure and Root Cause Analysis Logic 4
ENCLOEURE.C 5-15-90 Draft PROPOSED GENERIC LETTER (REFERENCE GSI B-56)
ALL HOLDERS OF OPERATING LICENSES OR CON 8'TRUCTION TO:
PERMITS FOR NUCLEAR POWER REACTORS.
RELATED REQUEST FOR ACTION PURSUANT TO 10 CFR 50.54 (f)
TO THE RESOLUTION OF GENERIC BAFETY ISSUE (GSI) B-56,
SUBJECT:
" DIESEL GENERATOR RELIABILITY" (GENERIC LETTER 90-
)
PURPOSE AND RACKGROUND:
This generic letter is being sent to all licensees of operating nuclear power reactors and to all construction permit holders to i
determine whether licensees will voluntarily implement NUMARC's Initiative 5A,= " Coping Assessment /EDG Performance,"'*' (s ee the guidance for monitoring and maintaining Enclosure C.1),
reliability provided in NUMARC Emergency Diesel Generator (EDG) 8700, Revision 1, Appendix D and an EDG reliability. program such da described in Regulatory Position C.6 of Regulatory Guide 1.9, Revision 3.
The Staff has issued Revision 3 of Regulatory Guide 1.9,
" Selection, Design, Qualification, Testing and Reliability of L
Diesel Generator Units Used as Class 1E Onsite Electric Power Systems at Nucir2r Power Plants" for the technical resolution of l
l-This revision integrates into a single document L
GS7 36.
gu. dance on EDG selection, design, qualification and testing.
in Revision 3 of Regulatory previously addressed (or provided)
Guide 1.108, Revision 2 of Regulatory 7uide 1.9, and Generic-Letter 84-15. Reporting of'EDG failures in conformance with 10 CFR Parts 50.72 and 50.73 will continue. Licensees are also encouraged to continue to report EDG failures to MPDRS.
REQUESTED ACTIONS TO BE TAKEN BY ADDRESSEES:
In order to determine whether any operating license or construction permits for facilities covered by this request should be modified, suspended or revoked, you are required, pursuant to Section 182 of the Atomic Energy Act and 10 C y
- 50. 54 (f),
l letter a statement as to your plans and the schedule for implementation at each facility to comply with Initiative 5A and Appendix D of NUMARC 8700, Revision 1 and with Regulatory
.,3, - n..., w s.t.
3 ti : m l
n l
t; Positions C.3, C.4, C.5 and C.6 of Revision 3 to RG 1.9 as your mothed for monitoring and maintaining EDG reliability levels for complishee with 10 CFR 50.63. If you do not plan to implement Initiative SA and regulatory positions noted above, in full or part, the statement shall identify with specificity the portions of the Initiative and Regulatory Guide which you do not intend to knplement and the basis therefore. If you plan to use a different method for monitoring and maintaining EDG reliability levels, your response should detail your approach and the schedule for that approach, and a schedule for implementation at Your i
each facility within 270 days from the date of this letter.
signed under oath and response should be submitted to the NRC, You should retain all documentation supporting this affirmation.
statement consistent with the records retention program for your 1
facility.
Licensees that implement HUNRRC Initiative 5A, Appendix D and Regulatory Positions, C.3, C.4, C.5, and C.6 of Revision 3 of-l Regulatory Guide 1.9 may include a request to change their plant Technical Specifications (TS) to incorporate the line-These line-item TS improvements noted in Enclosure C.2.
improvements are a result of the implementation.of programmatic requirements for monitoring and maintaining EDG target Guidance for the preparation of a proposed license reliability.
amendment to implement these line-item TS improvements is Conforming amendment requests will be provided in Enclosure C.2.
expeditiously reviewed by the NRC Project Manager for the facility.
MACKFIT DISCUSSION In Revision 3 of Regulatory Guide 1.9, the actions proposed by C.5, and C.6 the NRC staff in Regulatory Positions C.3, C.4, represent new staff positions and are considered a backfit in accordance with NRC procedures.
A backfit analysis of the type described in 10CFR 50.109 (a) (3) and 10 CFR 50.109(c) was performed and a determination was made that there will be a substantial increase in overall protection of the public hemith and that the costs are justified in view of this and safety, increased protection. The staff also believes that this approach is the most cost effective method for maintaining emergency diesel generator reliability since the prposed actions are-consistant with practices developed by the nuclear industry.
The backfit analysis is included in the Federal Register Notice
[
for the issuance of Revision 3 of Regulatory Guide 1.9, and will i
be made available in the Public Document Room along with the 176th and meetings of the Committee minutes of the 171st, to Review Generic Requirements that discussed the resolution of
j this generic issue.
PAPER *80P5 P3DUCTI0tt ACT REQUIREMENTS This request is covered by Office ref Management and Budget Clearance Number 3150-0011, which expires Yhe estimated average burden hours is 120 person-hours per licanse including assessing the new recommendations, searching
- response, data sources, gathering and analyzing data, and the required These estimated average burden hours pertain only to reports.
these identified response-related matters and do'not include the Estimates
)
time for actual implementation of requested actions.
of implementation of an EDG reliability program are reported in NUREG-1109, " Regulatory /BAckfit Analysis for the Resolution of j
Unresolved Safety Issue A-44, Station Blackout."
Comments on the accuracy of this estimate and suggestions to reduce the burden may be directed to the U.S. Office of Management and Budget, Executive Office Building, Nashington, D.C. 20503, and to the Nuclear Regulatory Commission, Records and Reports Management Branch, Office of Administration and Resources Management, Nashington, D.C. 20555.
If you have any questions on this matter, please contact your project manager.
Sincerely, James G. Partlow, Associate Director for Projects Office of Nuclear Regulation i
Enclosures:
- 1. C.1 NUMARC Initiative 5A
- 2. C.2 Guidance for the Preparation of License Amendments 1
l
,I
-w Enclosure C.1
)
NUMARC INITIATIVE SA uCOPING ASSESSMENT /EDG PERFORMANCE" (Ref. NUMARC-4700, Rev. 1, May 2,1990)'
The following verbatim quote of NUMARC's Initiative 5A is provided for convenience :
"Each Utility will assess the ability of its plant (s) to cope with a " Station Blackout."
Plants utilising alternate AC power for " Station Blackout" response which can be shown by test to be available to power the shutdown busses within 10 minutes of the onset of f
l
" Station Blackout" do not need to perform any coping
)
assessment.
Remaining alternate AC plants will assess their ability to cope for one-hour.
Plants not
]
l utilising an alternate AC source will assess their ability to cope for four hours.
Factors identified which prevent demonstrating the capability to cope for the appropriate duration will be addressed through hardware and/or procedural changes so that successful demonstration is possible.
As part of the coping assessment, utilities are required to choose an EDG target reliability (0.95 or 0.975) and are required to maintain that chosen reliability.
Accordingly, each utility will employ the following exceedence trigger values (on a plant unit basis) as the mechanism for monitoring EDG Target Reliability and support closure of Generic Issus B-56:
SELECTED EDG TARGET FAILURES IN FAILURES IN FAILURES IN RELIABILITY 20 DEMANDS 50 DEMANDS 100 DEMANDS 0.95 3
5 8
0.975 3
4 5
Additionally, each utility, in response to an individual EDG experiencing 4 or more failures in the last 25 demands, will demonstrate restored EDG performance by conducting seven (7) consecutive failure free start and load-run tests.
This reduced' form of accelerated testing shall be conducted at a frequency of no less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and of no more than seven (7) days between each demand.
Each utility will, if applicable, address this reduction in accelerated testing through changes to technical specifications or j
other appropriate means."
i
i 1
Enclosure C.3 5-31-90 Draft l
\\
GUIDANCE FOR TEE PREPARATION OF A LICENSE AMENDMENT REQ i
TO NODIFY EMERGENCY DIESEL GENERATOR SURYRILLANCE, ACTION, AND REPORTING REQUIREMENTS RACKGROUND
& program for monitoring and maintaining the reliability ofis an essential elemen emergency diesel generators (EDGs) assuring that the selected EDG target reliability for compliance is set.
The with the station blackout rule (10 CFR 50.63) establishment of this program in accordance with the guidance in i
Regulatory Positions C.3, C.4, C.5 and C.6 of Revision 3 to Regulatory Guide 1.9 will permit a reduction in the accelerated frequency of EDG monthly surveillanse requirements that are appleable to most operating plants, For the remaining plants, the implementation of an accelerated frequency for monthly EDGsu i
Also, a relaxation in the Initiative 5A, constitutes a backfit.
reporting requirements for EDG failures, consistent with Regulatory Position C.5 of Revision 3 of Regulatory Guide 1.9 is Consistent with the NRC policy on Technical appropriate.
improvements, this guidance is provided for a specification (Ts) license amendment request to implement these line-ites TS improvements, pIsCessioN Current plant T8 typically require an accelerated frequency of once per 7 days for conducting EDG monthly surveillance requirements when the number of failures exceeds 1 in the last 20 or 5 in the last 100 valid tests on a per diesel generator basis.
With the implementation of a EDG reliability program conforming the to the guidelines of Revision 3 to Regulatory Guide 1.9, staff has c tests is acceptable for imposing an accelerated test frequency Furthermore, the for monthly surveillance requirements.
accelerated testing may be suspended following 7 consecutive failure-free tests provided the time interval between consecutive tests is no less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
l I
i I
g_
s l
An acceptable alternative to the. existing. requirements of TS Table 4.8.1.1.2-1 is the following:.
Table 4.8.1.1.2-1 DIESUL GENERATOR TEST SCHEDULE NUMBER OF FAILURES IN TEST FREQUERCY 1
M9T 25 VALID TESTS
- _3 Once per 31 days
>4 once per 7 days **
(but no less than 24 bours)
Criteria for determining number of failures and valid demands shall be in accordance with Regulatory Position C.2.1 of Regulatory Guide 1.9, Revision 3, where the number of. demands and failures is determined on a per diesel generator basis.
The' criteria are based upon counting only those failures that have an impact on the capability of the EDG to respond to-a station blackout.
However, the ACTION requirements must be met for those fast start failures that are excluded for determining the number of failures in the last 25 valid tests.
j l
This test frequency shall be maintained until 7 consecutive failure-free start and load-run demands have been performed.
If subsequent to the 7 failure free tests 1 or more.
additional failures occur such that there are again 4 or more failures in the last 25 tests, the testing interval shall again be reduced as noted above and maintained until 7 consecutive failure-free tests have been performed.
4 The changes to Table 4.8.1.1.2-1 are in ths number of failures-in-the last 25' valid tests.
The
- footnote in changed to reflect the updated criteria on valid tests and failures provided_in-Regulatory Position.C.2.1 of Revision 3 to Regulatory Guide 1.9.
The criteria are based upon counting only those failures that have anrimpact on the capability of the EDG to respond to a station blackout.
Therefore, it is noted that the ACTION requirements must be met for those fast start-failures that are excluded for-determining the number of failures in the last 25 L
valid tests.
The ** footnote is changed to reflect testing requirements noted in Regulatory Position C.3.4 of Regulatory Guide 1.9 and Initiative EA of NUMARC 87-00.
Individual plant TS
'may have other notes relating to reducing the previous failure count'to zero following a complete diesel overhaul.
With the change in the requirements for initiating and terminating the L
i e
,e
l l
accelerated frequency for monthly surveillance requirements, i
notes related to reducing the previous failure count to sero following a complete diesel overhaul are no longer appropriate and should be deleted; The " Bases" Section for TS 3/4.8.1 should be updated to note that the basis for this TS also includes this generic letter.
Finally, with the implementation of recordkeeping requirements on EDG failures as a part of the above noted programmatic requirements for monitoring and maintaining EDG' reliability, the staff has concluded that a special report for all EDG failures is Accordingly, the following provides an no longer necessary.
acceptable alternative for TS 4.8.1.1.3. This is consistent with Regulatory Position C.5 of Revision 3 to Regulatory Guide 1.9:
4.8.1.1.3-Reports - Reports on failures of the emergency diesel generators, pursuant to the
]
requirements'of 10 CFR 50.73, shall include the
)
information noted in Regulatory Position C.5 of Regulatory Guide 1.9,
" Selection, Design, Qualification, Testing, and Reliability of Emergency Diesel Generator Units Used as Class 1E Onsite Electric Power Systems at Nuclear Power Plants," Revision 3, 1990.
StnG0JtY The alternative to the requirements of Table 4.8.1.1.2-1 will permit a reduction in the accelerated frequency of EDG monthly surveillance requirements.
Finally, a reduction in the reporting requirements for EDG failures is also appropriate with the implementation of-recordkeeping requirements noted above.
1 i
P l
.~..
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EMCLOSURE D 5-30-90 DRAFT BACKFIT ANALYSIS GI B-56, " DIESEL RELIABILITY" Backgrouad The NRC staff has issued Regulatory Guide 1.9, Revision 3,
" Selection, Design, Qualification, Testing, and Reliability of Emergency Diesel Generator Units Used as Class 15 Onsite Electric
-Power Systems at Nuclear Power Plants," constitutes resolution-of J
Generic Safety Issue B-56, " Diesel Generator Reliability."
Revision 3 of Regulatory Guide 1.9, integrates into a single i
]
regulatory guide pertinent guidance previously addressed in Regulatory Guide 1.108, " Periodic Testing of Diesel Generator Unit.s Used as Onsite Electric Power Systems at Nuclear Power Plants,H Regulatory Guide 1.9, Revision 3, and Generic Letter 84-15. Guidance provided in Revision 3 of Regulatory Guide 1.9 supersedes Regulatory Guide 1.108, and Regulatory Guide 1.108 is hereby withdrawn. Withdrawal of Regulatory Guide 1.108, however, does_not alter any prior or existing licensing commitments based on Regulatory Guides 1.108 and 1.9 and Generic Letter 84-15.
These are still considered to be in effect until a licensee changes plant Technical Specifications.
In addition, the nuclear power industry has revised Appendix D of NUMARC-8700, which provides guidance for-monitoring nuclear unit EDG reliability levels and for remedial actions to restore reliability levels above-the target reliability selected for station blackout. The NRC staff has reviewed Appendix D and finds it's. guidance acceptable for monitoring and maintaining EDG reliability levels, and they have referenced this guidance (as applicable) in Regulatory Guide 1.9, Revision 3. Table 1 of this regulatory guide cross-references the guide and NUMARC 4700, Revision 1, Appendix D (5-2-90).
The resolution of U8I A-44, " Station Blackout" identified G8I B-56, " Diesel Generator Reliability" an oustanding safety issue related to USI A-44; and also noted that the resolution of B-56 would provide guidance for use by the staff and industry for reviewing diesel generator reliability programs. The regulatory analysis for U8I A-44 is contained in NUREG-1109, " Regulatory /
Backfit Analysis for the Resolution of Unresolved Safety Issue Station Blackout", June 1988. This regulatory analysis A-44, evaluated costs associated with implementation of EDG reliability i-programs and concluded that operation of onsite emergency AC Power sources shuld be ensured by a reliability program designed to monitor and maintain EDG reliability levels consistant with those selected for compliance with the station Blackout Rule.
The staff finds the regulatory analysis developed for U8I A-44 d
-nw
4 i
- l ;
-applicable to the resolution of 01 3-56, and therefore a new regulatory analysis will not be developed for et B-56.
The fellowing int'ormation is provided in answer to specific
)
requirements of paragraph (o)-of to CFR 50.109.
)
t (1) statement of specific objectives that the proposed backfit is to achieve.
The objectives for issuing Revision 3 of Regulatory j
Guide 1.s are as fo;1ows:
(a)
To provide guidance on monitoring EDG reliability 1evels selected for compliance with 10 CFR 50.63, Hatation Blackout," and reviewing EDG reliability
-l programs.
(b)
To incorporate guidance into a single regulatory guide that has been addressed through two regulatory' guides (1.108 and 1.9, Rev. 2) and Generic Letter GL 84-15.
The first objective involves a backfit, the second objective does not.
General description of activity that would be required (2) by the licensee or applicant to complete the backfit.
A generic letter will be sent to.all licensees of operating nuclear power plants and all construction permit holders who currently rely upon EDGs to comply with 10 CFR 50.63.
The letter will request a statement of plans-and schedule.for monitoring and maintaining s
EDG reliability levels per guidelines contained in NUMARC's Initiative 5A, NUMARC-8700, Revision 1, Appendix D (5-2-90) and Regulatory Positions C.3, C.4, C.5 and C.6 of Regulatory Guide 1.9 4 Revision 3 or identification and justification of an' alternative plan.
The generic letter also identifies a need for revisions to plant Technical specifications as determined by the course of action selected.
The. licensee or applicant will need to review current methods for monitoring and maintaining EDG reliability levels and determine if current practices are consistent with tho' guidelines noted above, or if an alternative approach is desireable. Since most plants have reliability programs similar that described in
[.
the guide and NUMARC's guidance, it is likely that only confirmation would be required.
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1 Revisions to plant Technical specifications will require plant specisio reviews since some existing Technical specifications pre-date Regulatory suidas 1.103, 1.9, Revision a and OL 84-15. Committaent to the
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.i use of guidance based on current industry-wide practices and the relaxation of mooelerated testing per NUMARC's Initiative SA and Regulatory Guide 1.9,.
Revision 3 will therefore be licenses specific. NUMARC has indicated that they anticipato utilities will address this reduction in accelerated-testing through J
revisions to current plant Technical Specifications.
(3)
Potential change in the risk to the public from accidental offsite release of radioactive material.
The USI A-44-backfit analysis (NUREG-1109) identified the risk reduction for 100 operating reactors to be 145,000 person-rem and thereby supported the Commission's conclusion that 10 CFR 50.63 provided a j
substantial improvement in the level of public health and safety protection.
Inherent in the above finding was the understanding that adequate EDG reliability levels would be maintained (see Regulatory Guide 1.155) and that further pidance would be provided through the issuance of Revision 3 of Regulatory Guide 1.9 which constitutes the resolution of GI B-56, " Diesel Generator Reliability."
Implementation of the guidance provided in Regulatory Positions 3, 4, 5 and 6 in Revision 3 of Regulatory Guide 1.9, as taken from NUMARC's revised Appendiz D, will provide-the staff and industry with common guidance for monitoring and maintaining EDG reliability 1evels selected for compliance with 10 CFR.50.63.
The improvement in the level of public health and safety estimated for USI A-44 is thereby further ensured.
(4)
Potential impact of radiological arposure of facility employees.
No radiological exposure is projected since the monitoring of EDG reliability and implementating an EDG reliability program is not expected to require personnel to be exposed to radiation.
(5)
Installation-and continuing costs associated with the backfit, the cost of facility downtime, or the cost of construction delay.
No facility downtime or startup delays from L
construction or installation are envisioned with the issuance of Revision 3 of Regulatory Guide 1.9 3
)
kl since no fasility modifications are needed.
The seatinuing oests assestated with asiataining a diesel reliability program should be saali, stase operating plaats surrently seaduet acathly surveillanee tests to monitor BDe reliability and have some fers of am BDS Cost estimates for improving BDe maintenance program.
reliability, if necessary, were estimated to be
$150,000 to $400,000 per remotor (Nuase-ites).
It is also noted that industry information provided by WUMARC indicates that industry-wide BDe reliability levels are surrently 97% to 98%, so it is espeeted that the actual oost of implementation beyond those measures surrently employed will be less than acted above. In view of the present BDG reliability levels and use of recommended industry practises, impact on licensee resources should be saali or megligible.
In addition, NUMARC's revised Initiative BR, # Coping Assessment /EDG performance from WUMARC-8700, Revision states that utilities should saistain BDG 1, 5-2-90, reliability at target levels chosen for compliance with 10 CFR 50.63. The staff has interacted with NUMARC's D-56 working group in the development of Revision 3 of Regulatory Guide 1 9 and NUMARC's Appendia D.
The potential safety impact of changes in plant or (6) operational complexity, including the relationship to proposed and existing regulatory requirements.
Regulatory positions C.3, C.4, C.5, and C.6 will act introduce additional operational complexity since monthly surveillance testing of 3DGs has been implemented for some time by all licenses.
Monthly surveillance testing will be the basis for monitoring EDG reliability levels and assessing the ef'estiveness of the on-site 3D0 reliability program.
The relaxation of accelerated testing (from that in RG 1.108, Rev. 2) through focusing on the problea EDG should enhance life Therefore, there will be no expectancy of EDGs.
adverse impact on plant safety from implementating the proposed actions.
The estimated resource burden on the NRC associated (7) with the proposed backfit and the availability of such resources The principal cost to the NRC would be associated with reviewing EDG reliability programs at selected plant p
sites, as needed.
It is estimated that such efforts would not exceed 0.5 person-month per site.
Using an estimated cost of $12,000 per staff month and 15 sites, 4
l h
L the total oost would be $150,086.
The devolepseat of guidelines by staff and saGustry representatives which reselted in Revision 8 et Regulatory evide 1.9, and af NUMhac-s700, Rev. 1, appendia D provides for uniform guidamos and ooaformity of approaches, thereby reducing rac review eests.
(s)
The potential impact of differences in facility type, design, or age on the relevance and practicality of the proposed backfit.
Differences in facility type, design, or age will not have any signitionat effect on the relevamos or practicality of complying with the 3D0 reliability monitoring program.
In addition, Revision 3 of Regulatory Guide 1.9 and NUMARc-8700, Rev. 1, hypendia D have been subjected to estensive discussions with NUMARC's 3-56 working group and also issued for external review to solicit a wide spectrum of review and ensure conformity with provea practice, thereby further reducing potential impacts.
(9)
Whether the proposed backfit is interia or final and, if interim, the justification for imposing the proposed backfit on an interia basis.
The proposed action is final.
i 5
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pacLosuma a 5-39-90 (vsto-os) l DREPT FEDERAL REGIsTSR MOTICE l
(Ref. Resolution GSI 3-55) f NUCLEAR REGULATORY COMMISSION j
Regulatory Guider Issuance, Availability t'
The Nuclear Regulatory commission has issued a revision to a guide in its Regulatory Guide Series.
This series has been developed to desoribe and make available to the public such information as methods acceptable to the NRC staff for implementing specisio parts of the commission's regulations, l
techniques used by the staff in evaluating specific problems or postulated nooidents, and data needed by the staff in its review I
of applications for permits and licenses.
The issuance of Replatory Guide 1.9, Revision 3, " selection, l
Design, Qualification, Testing, and Reliability of Baergency Diesel Generator Units Used as class is onsite Electrio Power ggggg{tyggg gggglggigg gg systems at Nuclear Power Plants,H Generio safety Issue 3-56, " Diesel Generator Reliability."
Revision 3 of Regulatory Guide 1.9, integrates into a single regulatory guido pertinent guidance previously addressed in Regulatory Guide 1.108, HPeriodio Testing of Diesel Generator Units Used as onsite Electric Power Systems at Nuclear Power Regulatory Guide 1.9, Revision 3, and Generic Letter Plants,H 84-15. Guidance provided in Revision 3 of Regulatory Guide 1.9 supersedes Regulatory Guide 1.108, and Regulatory Guide 1.108 is hereby withdrawn. Withdrawal of Regulatory Guide 1.108, however, does not alter any prior or existing licensing commitments based on Regulatory Guides 1.108 and 1.9 and Generio Letter 84-15.
These are still considered to be in effect until a licensee changes plant Technical speciiications.
Regulatory Positions C.3, "EDG Reliability Goals and Monitoring" and C.6, " Emergency Diesel Generator Reliability Program" of Revision 3 of Regulatory Guide 1.9, will be used by the staff, in conjunction with NUMARC-8700, Revision 1, Rppendis D (5-3-90),
for monitoring and maintaining EDG reliability levels against those selected for compliance with 10 CFR 50.63, " Loss of all alternating current power" and for reviewing EDG reliability programs. compliance with these regulatory positions is a backfit. A backfit analysis for this aspect of the regulatory j
i guide is included here.
comments and suggestions in connection with (1) items for inclusion in guides currently being developed or (2) improvements
l l
la all published guides are emoeuraged at any time.
Written somments may be submitted to the Regulato n Publications Brameh, Division of Freedom of Information and Publications Servises, office of Administration, U.S. Nuclear Regulatory Commission, Washington, DC 30555.
Regulatory guides are available for inspection at the Commissica8s Public Document Room, 3130 L 8treet NW., Washington, DC.
Copies of issued guides may be purchased from the sovernment Printing office at the current GPO prios.
Information on current 070 prices may be obtained by contacting the Superintendent of Documents, 0.8. Government Printing Offlee, Post office Boa 37083, Washington, DC 80013-7088, telephone (202) 875-2060 or (302)375-3171.
Issued guides may also be purchased from the National Technical Information servios on a standing order basis.
Details on this service may be obtained by writing NTIs, Sass Port Royal Road, springfield, TR aatst.
(s U.s.C. sla (a))
Dated at this day of 1989.
For the Nuclear Regulatory Commission Eric s. Beckjord, Director office of Nuclear Regulatory Research
0'o ENCLOBURE F
i L
NUMARC 87-00 SUIDELINES AND TECHNICAL BASES FOR NUMARC INITIATIVES ADDREl$1NG STATION BLACK 0UT AT LIGHT WATER REACTOR $
REY!$10N 1 NAY 2, 1990 I
APPENDIX D I
EDG RELIA 51LITY PROGRAN l
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INTRODUCTION Utilities are required to ensure that the Energe cy Olesel Generators (EDGs)d credited in each facility's station blackout cop g assessment are maintaine stion 3.t.4.
Initlative 5A at or above the target reliability selected per presents triggers values for 20, 50 and 100 demands that were developed as the This appendix provides sechanism to monitor nuclear unit reliability levels.
guidance on monitoring these levels in accordance with Initiative EA, along cith guidance on remedial actions that may be considered in response to exceedance of the trigger values. These remedial actions are designed to restore nuclear unit reliability levels above the selected target reliability.
This appendix consists of two sections. Section 0.1 provides definitions of The terminoley and concepts key. terms related to the EDG Reliability Program. resented in this section fndustrywide Plant Performance Indicator Program (PPIP) managed by the InstituteofNuclearPowerOperations(!NP0).
Section 0.2 provides guidance on methods to monitor nuclear unit EDG reliability levels and on remedial. actions to restore reliability above the i
The remedial actions set forth in this section selected target reliability.
are derived frein current industry practices that have proven effective in saintaining EDG reliability.
The associated Topical Report to this a pendix provides additional information en root cause analysis, recognized anal tical and quality improvement techniques, and further detail on the e ements (critical review elements) of an EDG reliability program. These elements are:
Surveillance that ideatifies EDG support systems and (1) subcomponents, frequency and scope of testing, and incorporates manufacturer's recommendations.
Performance monitoring of important parameters on an ongoing basis
- (2) to obtain information on the condition of the EDG and key components so that precursor conditions can be identified prior to failure.
Maintenance designed for both preventive and corrective actions (3)
~
based upon operating history and past maintenance activities, vendor reconnendations, and the results of surveillance testing, Failure analysis and root cause investigation to assist in (4) developing effective corrective actions to prevent recurrence of failures.
EDG problem closecut process to ensure the resolution of a failure (5) or a problem is properly implemented and successful.
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EDS reliability data systes to ensure the availability an (6) reliability.
l Itisrecbpnised This appendix represents one approach to EDG reliability.
-that there are existing programs that have preven extremely successgo maintaining high EDG reliab lity. supplant such programs, but simply to provide guidance to addre EDG reliability for utility use, as appropriate.
t 9.1 DEFINIT 100ts MIMaER OF START DEMANDS including all start only demands and All valid and inadvertent start demandsload run demands, whether by automatic all start demands that are followed byA start only demand is a demand in which the 1
',or manual initiation.enerator is started, but no attempt is made'to load the genera See gExceptions*below.
NUMttR OF START FA1LUF.Es Any failure'within the emergency generator system that prevents the gener and voltane is classified as a from achieving specified frequency (or speed)llance tesi, the generator can be brought to rated speed (For the monthly survei valid start failure.
and voltage in a time that is recommended by theSimilar manufacturer to minimize stress and wear.
to reach rated speed and voltage in the precise time required by technical specifications, the start attempt :s not considered a failure if the test' See demonstrated that the generator would start in an emergency.)f maintenance Exceptions' below.
Any condition identified in the course o that definitely
' inspections (with the emergency generator in the standby mode)d should be would have resulted in a start failure if a demand had occurre counted as a valid start demand and failure.
i NUMBER OF LOAD-RUN DEMANDS j_
To be valid, the load run attempt must follow a successful start and meet one (See ' Exceptions' below.)
'of the following criteria:
L a load run of any duration that results from a real (e.g., not a o
test) automatic or manual signal a load run test to satisfy the plant's load and duration test i
e specifications
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other operations (e.g., special tests) in which the e e
percent of design load 3
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i glUMatt OF LOAD tDN FA1Lintts A load run failure should be counted when the emergency generator starts but l
does not pick up load and run successfully. Any failure during a valid load-i run demand should be counted. See ' Exceptions' below.
(Formonthly
' surveillance tests, the generator can be loaded at a rate that is recomended Similarly, if the generator by the manufacturer to alnimize stress and wear.
fails to load in the precise time required by technical specifications, the lead run attempt is not considered a failure if the test demonstrated that the Any condition identified in generator would load and run in'an emergency.)
the course of maintenance inspections (with the emergency 1
- demand had occurred should be counted as a valid load run demand
~
4 EXCEPT10NS Unsuccessful attempts to start or load run should not be counted as valid demands or failures when they can be definitely attributed to any of the L
following:
spurious operation of a trip that would be bypassed in the emer ency operation mode (e.g., high cooling water temperature o
trip f
malfunction of equipment that is not required to operate during theemergencyoperatingmode(e.g.,synchronizingcircuitry) o intentional temination of the test because of alarmed or observe that would abnormal conditions (e.g., small water or oil leaks) o not have ultimately resulted in significant emergency generator damage or failure component malfunctions or operating errors that did n o
withinafewminutes(i.e.,withoutcorrectivemaintenanceor significantproblemdiagnosis) c l
a failure to start because a portion of the starting system was disabled for test purposes, if followed by a successful start with l
e the starting system in its normal alignment I
Each emergency generator failure that results in the generator being declare inoperable should be counted as one demand and one failure.
during corrective maintenance and the successful test t the EDG has not been declared operable again.
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C-tgitT EDS MELIABILITY:
The average reliability of all EDCs being combined at an individual nuclear unit.
1 i
The value (based on number of failures dering a SCEEDENCE TRittER VALUE: comparative number of demands? et whici effectiveness of EDG reliability efforts are initiated.
i Maintenance perfomed to correct a component or CORRECTIVE M!NTENANCE:subcomponent which is determined to be incap' PREVENTATIVE MAINTEMANCE:Maintenance performed with the expectation of preventing a component er subcomponent from failing to perfors its function.
D.R MONITORING EDS RELIABILITY This section provides methodology to monitor, maintain, and im t
reliability.and compares'this data with predetermined values (trigger values to determi It hould be s' proper course of action to support EDG reliability soals.
Toted that a reliability value derived from a sample is only an approximate This is because the indi.ttien of an EDG's true underlying reliability.
r:11.b'11ty from samples will vary from the true underlying reliability due to The trigger values take statistical variations based upon the sample sizes.Therefore, the comparison of the into account such statistical variations.
' reliability indicators against the trigger values provides an accurate The indication of reliability levels from which to base remedial actions.
method of calculating these reliability indicators is given in Section 0.2.2.
The methodology in this section consists of four parts:
(1) maintainingdataonsuccessful'andfailedEDG start and ond run demands evaluating the unit EDG reliability indicators for the last 50 and
- (2) last 100 demands as well as EDG performance over the last 20 demands via the prescribed methodology relating the calculated EDG perforsance and reliability indicators (3) to trigger values established for the selected target reliability taking remedial actions for individual failures and for (4) exceedence of one or more trigger values The sample size and action levels are based on a surveillance testing interval for each EDG of once per month. Details of each step are presented in the sections that follow.
5 l
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3,3.1, llaintaining EDG Reliability Data s and failures.
' Utilities should maintain records on EDG demands, successe fach success or failure should be charactertred using the Industrywide
?
methodology to establish valid demands, i
Perfomance Indicator Program (PPIP)d runs.
The rules governing the INP0 successful starts and successful loa l
' methodology are sistler to the intent of NSAC 108, "he Ra'inbil' ov af rueroenev Diesel Generators at U.S. Nuclear N.;;r P' ants
'Wyckaddl.
Determining Performance and Reliability Indicators 9.3 2 i
The calculation of the performance and reliability indicators of a nucleart unit is comprised of two components:Since not all EDG) demands include both (1
l Ioad run demands, data on these two reliability components should be lead run reliability.
i An equal number of start and evaluated individually and then combined.
demands and load run demands may not occur in the same time interval.
Determining Unit EDG Performance Indicator for Last to Demands D.t.t.1 Determining '.he unit EDG performance indica.or for the last 20 demands i accomplished by suming the number of failures observed in the last to st demands and.the number of failures observed in the last 2 for all of the EDGs serving as standby power supplies to that unit.
Determining Unit EDG Reliability Indicator for Last'50 Demands D.t.t.1 Determining the unit EDG reliability indicator for the last 50 demands is accomplished by suming the number of failures observed in the last 50 s demands and the number of failures observed in the last 5 j
A time for all of the EDGs serving as standby power supplies to that unit.
limit of four years is suggested on the data.
Deternining the plant unit EDG reliability indicator for the 1
tramela:
last 50 demands f
AsitehasonenuclearunitwhichhastwoEDGs(EDG1andEDG2),
The last 50 start demands consisted of 30 start demands on EDG 1, j
The last 50 load run demands and 20 start demands on EDG 2. consisted of 25 load run dem on EDG 2.
EDG 1 has experienced two starting related failures in its last 30 EDG-1 start demands and EDG 2 has experienced no starting re failures in its last to start demands. Thus, the u I
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last 25 load run demands. Thus the unit has experienced two l
load run failures in the last 56 load run demands.
The tetal number ef nucleer untt EDG Rellability Indicator -
failures experienced in the last 50 demands is four (two start failures for the unit plus two load run failures for the unit).
Therefore the reliability indicator is four out of 50.
i Determining Unit EDG Reliability Indicator for Last 100 Demands 9.t.t.3
. Determining the unit EDG reliability indicator in the last 100 demands is
' accomplished by sunning the number of failures observed in the last 100 start demands and the number of failures observed in the last 100 load ru 1
A time for all of the EDGs serving as standby power supplies to that unit.
limit of four years is suggested on the data.
9.t.t.4 Special Conditions The evaluation of a nuc* ar unit's EDG performance and reliability indicators should take into account the demand and failure experience of all EDGs which For nuclear units with fully shared Irovidestandby' power'forthetheunit.DGs between nuclear units (for exa
, same evaluation based on all the EDGs shoald be performed.so i
the specific nuclear unit are to be includa1.
For a two unit plant with one EDt. dedicated to the first unit, one tramele:
EDG dedicated to the second unit a3d a third EDG shared between units, the EDG reliability indicator for the first unit should cons.ider only the failure experience of its dedicated diesel and Likewise, the EDG reliability indicator for the shared diesel.
the second unit should consider the failure experience of its dedicated EDG and the shared EDG, The shared EDG is applied to t
both units.
Some units have EDGs of different designs which serve the function ofE providing standby power supplies.
frocedures and maintenance procedures may be evaluate n this case a unit would have more than one set of reliability indicator evaluations to perform and to compare to program triggers, A two nuclear unit site has five EDGs. Three are of the same Examela:
Two of these three serve the emergency sanufacturer and design.
n busses of one of the nuclear units and the third serves as a swing The remaining two EDGs are of a different between nuclear units.
These manufacturer and design than that of the first three.
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remaining two serve the emergency buses of the second nuclear Since each of,thase EDGs have the capability to provide for unit.
safe shutdownIve.ey are roughly equivalent free a station bla th One set of re, 50 and 100 demand indytters is risk perspect calculated using the combined experience of three EDGs of the same type and a second set of indicators is calculated usingthe The results of these combined experience of the other two EDGs.
separate evaluations are to be compared to appropriate reliability triggers as described in Section D.t.3.
J Table D.t 1 provides methods that can be used for combining unit EDG
' experience for different EDG configurations.
Table D.t 1 NETH005 FOR COM61NING UNIT ED6 EXPER!tNCE i
Nethod for Combining EDS Configuration Use combined failures of all EDGs 2,3,4 EDGs dedicated to a unit Use combined failures of all EDCs 1,3,4 EDGs shared between units for all units 1 dedicated EDG'at each unit and Each unit uses the combin6d failures of its dedicated EDG and the shared I shared between units EDG I dedicated EDGs at each unit and Each unit uses the combined failures of its dedicated EDGs and the shared 1 shared between units
- I EDG Use the combined failures of all t dedicated EDGs and 1 or more EDGs or separately consider the diverse EDGs within the same unit failures of different EDGs Relating the Calculated Unit EDG performance and Reliability Indicators to Trigger Values for Selected Target Reliability D.t.3 i
L D.t.3.1 Use of the Exceedence Trigger Values Failure rate triggers are used to indicate when EDGs do not meet the selected This sub section incorporates the triefler values target reliabilities.
Table D.!-
presented in Initiative 5A for the selected target reliabilit' es.2 The selected EDG target reliability EDG target reliability of 0.95 or 0.975.is the allowed underlying EDG targ used in Table 3.8 on page 319 to establish the coping duration category for a station blackout.
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l EXCEEDENCE TRISSER VALUES 8
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Selected Target Failures In Failures In Failures In Re1, ability to Demands 50 Demands 100 Demands 4
O.95 3
5 8
0.975 3
4 5
The exceedence trigger values for failures in 20 demands, actions should be taken to restore the selected target reliability.
Periodic testing is normally conducted at one month intervals for each CDG.After eac' Real demands may also occur between testing intervals.an EDG
.j failures in the last 20, 50 and 100 demands :hould be compared to the exceedence trigger values for the selected target reliability.
D.t.3.1 successful Test / Demand If the most recent test is successful, then no additional actions are required unless already in a past exceedence category (see Section 0.2.4.5).
Unsuccessful Test / Demand. No Trigger Values Exceeded 9.t.3.3
)
4 If the most recent test results in a failure and the failures in the las i
demands, the failures in the last 50 demands, and the failures in the last 100 demands are less than the trigger values in Table D.2 2 for the selected target reliability, then the actions set forth in Section D.t.4.1 Actions for Plants That Do Not Exceed Any Trigger Value, should be followed.
The most A unit has a selected EDG target reliability of 0.95.
recent failure was the second failure in the last 20 demands, the tramnie:
third failure in the last 50 demands and the sixth failure in the The two failure's 'are less than the three last 100 demands.
failure trigger value for the failures in 20 demands, the three j
failures are less than the five failure trigger value for the failures in 50 demands and the six failures are less than the
^
- Hence, eight failure trigger for the failures in 100 demands.
The actions none of the trigger values were equaled or exceeded.
3 set forth in section 0.t.4.1, Actions for plants That Do Not Exceed Any Trigger Value, should be followed.
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s Unsuccessful Test /Desend One Tripper Value Exceeded s.g.3.4 3f the most recent test resulted in a failure and either:
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the failures in to demands are equal to or greater thanThe l
trigger value for the selected target reliability in Table D.t 2.
(1)
B the failures in 50 demands are equal to or greater than the trigger value for the selected target reliability in Table D.t 2, l
(t)
B the failures in 100 demands are equal to'or arenter than the trigger value 'for the selected target reliability in Table D.2 2.
(3) then the actions set forth in Section D.t.4.2, Actions For Plants Exceeding A
$1ngle Trigger, should be followed.
The most A unit has a selected EDG reliability tarlet of 0.35.
recent failure was the third failure in tie last 20 demands test, tu mle:
the fourth failure in the last 50 demands, and the sixth failureT i
l in the last 100 demands.
three failure trigger value for the failures in 20 deman failures in 50 demands, and the six failures are ess than the eight failure trigger value for the failures in 100 demands.The actions set one trigger value was equaled or exceeded.
fortti in section 0.t.4.2, Actions for Plants Exceeding a single Hence Trigger, should be followed.
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Unsuccessful Test / Demand - 50 and 100 Demand Trigger Values l
D.t.3.5 Exceeded
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If the most recent test resulted in a failure and:
l the failures in 50 demands are equal to or greater than the l
trigger value for the selected reliability target in Table D.2 2, l
(1) 4 51 the failures in 100 demands are equal to or greater than the trigger value for the selected reliability target in Table 0.12, (t) then the actions set forth in Section D.2.4.3, Actions For Plants That Exceed the 50 and 100 Demand Triggers, should te followed.
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A unit has a selected EDG target reliability o
..l 1385131-the fifth failure in the last 100 demands. The four fa 4
equals or exceeds the fevr failure tripper value for thei ailu f
t in 50 demands and the fifth failure oevals or exce failure trigger for the fattures in 100 demands. Hence,-both i
trigger values were equaled or exceeded. The actions se section 0.2.4.3, Actions for Plants That Exceed the 50 and 1 Demand Triggers, should be followed.
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302.4 Actions for Individual Failures and for Excee Trigger Values h
This section provides the response. action guidelines to EDG Figure D.t 1 illustrates the The left mott flow path represents actions to be taken exceedence of one or more trigger values.
in response to individual EDG failures, but when no trigger value actions to be taken.
The center flow These actions are detailed in Section 0.2.4.1.t igger value for either 20,
,' path represents the actions to be taken when the rThese actions Are de exceeded.
l The right. flow path represents the actions to be taken when
$0 or 100 demands is exceeded.
These actions re for both the 50 and 100 demands have been exceeded.
detailed in Section 0.t.4.3.
DG that Section D.t.4.4 provides-guidance on actions to address an l
has experienced 4 or more failures in the last Il demands.
i of actions arising from
)
,$ection D.2.4.5 provides details on the durat on 1
exceeding one or more of the trigger values.
5ection D.t.4.6 provides guidance on recordkeeping.
Section D.t.4.7 provides guidance on reporting to WRC.
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Actions for Plants That De Not Exceed Any Trigeer Value 3,3,4.1 For plants where the observed number of failures in the last 20, 60 and the last 100 demands are less than the associated trigger values fer the selected target reliability, but have experienced an unsuccessf01 start or lodd run, the following actions should be performed:
determine the root cause of each new failure (1)
(t) torrective actions
'EDG failure do not preclude any immediate actions currently Testing and response to (DG failures fulfill regulatory requirements.(corrective actions) should be consistent with cur Specifications.
The nomal plant practices and procedures to accomplish the noted reliability The results of root actions do not need to be modified specifically for EDGs.
cause evaluations in response to EDG failures should be incorporated intoDeta appropriate corrective actions.
(1)
Determine the Root Cause of tach New Failure A root cause analysis The cause of each new failure should be determined. capability is g A root cause analysis of any (DG failure should include:
process.
investigatin'g the cause of failures in sufficient detail with appropriate cause codes for tracking Corrective Maintenance (CM),
a.
addressing the cause of failures to the highest level at which they can be by an applicable and effective maintenance task, b.
testing task, procedure change, operations change, or design modification.
Additional information on root cause analysis is provided in the Topical Report.
A root cause analysis should be done to the extent necessary for determination of the cause of each failure. The threshold for performing /not performing detailed root cause analysis is a function of the failure being examined.
(1)CorrectiveActions Corrective actions should be implemented following the root cause analyses of These actions, to the extent possible, should be prioritized and scheduled based on the significance of their contribution to the EDG failures.
preventing a recurring failure. Timely and proper implementation of 13 4
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L ',)
a corrective actions will reduce the 1tkeltheod of future failures and help prevent exceedence of reliability trigger values.
i 3.t.4.1 Actions for Plants Exceeding a Single Trigger
~
Wuclear units that exceed the last to demand failure triager er the 1ast 50 demand failure trigger or the last 100 demand failure trigge reliability based on the actual EDG failures experienced.
her (1) determine the root cause of each new failure (2) review applicable past failures (3) evaluate the corrective maintenance tracking history assess actual failure history against critical review (4) elements (5) corrective actions A detailed description of these actions is provided below.
4 (1) Determine Root Cause of Each New Failure This action determines the cause of new failures as provided in Section D.2.4.1.
1 (t) Review Applicable Past Failures The review of observed EDG failures associated with the trig that EDG testing, maintenance, operational practices, design changes, etc.Th would restore target reliability.This review attempts to establish a pattern in the the last 100 demands.
For experienced f ailure modes and the underlying reasons for th With this.information it would be possible to specify actions that could be taken to preclude or minimize the recurrence of many of the observed modes.
The product of this task action would be a list of effective failures.
changes that could be implemented.
NOTE: Action (2) may be performed concurrently with Action (3).
14 f
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(3)CorrectiveMaintenanceTrackingHistory Nuclear units that have exceeded one trigger should evaluate the 506 The history
)
history and onseing CM tracking.
CorrectiveMaintenance(C activities to the extent appropriate based on the should identify previous This history should provide cognisant plant personnel i
nature of the failures.
cith additional inforsation that would be useful in identif ng precursors to are available further reliability degradation. Aspartofthishistoryfailurewithinthe t
, data permits, each CM related to an EDG system componen last 100 demands would be evaluated and categorised in fou The severity of each CM would be classified in cause classification.
accordance with the IEEE Std 500 Reliability Data and the Nuclea
~
severity levelst immediate i
Reliability Data System (NPADS)1e forsat for tracking EDG CM is provided A sam >
degraded and inci ient.Dt er formats tint accomplish the same purpose are acceptable, Figure D.2 2.
Figure 0.t 2 W.ective Maintenance Tracking History t
l immediate/
t Component Deeraded' Fvunien(s)
Desertpton CorreaW
)
CWe involved Searstem insipient
- Affemed, el Fatore Amien(s)Taken (1)
(2)
(3)
(4)
(s)
(a)
(7)
)
1 Heeding Dennitione:
t CM e: A unique identrier for the work request or work outhorization which was Worsfied h reopense to th Component involved: N unique equipmers piece number (s) for th i
8.
8.
L ImmediatecogradedSncipient: Classveatbn of the falure neerding to the IEEE soo severtry indet tion or lac).
the immediate claseration in NPRDS is equivalent to the estastrophic classNeation in IEEE soo.
?
Function (s) Affected:Idertifiestion of the funcion(s) of the EDG impacted by the failure (Lo.,
S.
Corrective Action (s) Taken: A brief desorption of action taken h response to failure (i.e., repair, wperations, shuidown, etc.).
7.
etc.).
15
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The Corrective Maintenance history and ongoing tracking should tak0 care to distinguish between corrective maintenance actions and o The ong'ofnp CN tracking should continue until the EDGs are no longer considered to be tn an exceetence category as per Section D.2.4.5.
saintenance.
l After implementing the CM tracking, plant personnel would Assess Failure History Against Critical Review Elements (4)
Once the specific failures have been reviewed and improvements identified, anidentified
' evaluation should be performed to determine if any failure patterns The by Actions (2) and (3) are indicative of programmatic deficiencies.
evaluation should determine whether the observed pattern of failures are For related to any of the reliability program critical review eleme necessary to review each of these root cause analyses to detemine wh element if any is implicated.
review elements is contained in the Topical Report.
(5) Corrective Actions These actions are similar to that provided in Section D.2.4.1, except that the scope may be greater and may include programmatic elements as a result of the review to determine a pattern of failures. Timely and pro >er implementation of changes that improve reliability will reduce the likeliiood of subsequent failures and exceedence of another trigger value.
Actions for Plants That Exceed the 50 and 100 Demand Triggers f
D.2.4.3 Nuclear units exceeding both the 50 demand and the 100 demand failure triggers should take additional actions beyond those required of plants exceeding a The same basic actions as for nuclear units with a new single trigger value.
failure with no trigger value exceedence and for nuclear units exceeding a single trigger value should be performed including the effects of additional The actions should be:
f>'luresastheresultofactions(1)and(4).
(1) determine the root cause of each new failure (2) review applicable past failures avaluate the corrective maintenance tracking history (3) assess actual failure history against critical review elements (4)
(5) reliability program changes (6) corrective actions Actions (1) through (4) are similar to those discussed in the previous sections.
16
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f (5)
Reliability Progras changes The exceedence of both the 50 and 100 demand trigers requires consfderation The. previous be given to a comprehensive. review of the reliab, ity program. remedial actions in response to EDG failures would a i
Therefore, emphasis been successful in maintaining the desired reliability.
rather than on response to should be placed more on programatic issues,be given to assistance by I
Consideration may also
. individual failures.
independent reviewers such as engineering or corporate staff, vendor or consultant personnel In assessment of the reliability program to the extentimpr
, cecessary to achieve needed improvements. Many qualityare av necessary, improving reliability programs.
An example of this review activity incorporating recogniaed analytical and quality improvement techniques is provided in the Topical Report as useful information.
l (6)
Corrective Actions
.Fe.10 wing the comprehensive program review, improvements in the form of restructuring the reliability program are warranted to reinstate accomplished to restore confidence in the ability to maintain the chosen EDG I
reliability.
target reliability.
D.t.4.4 Probles EDG A problem EDG is defined as an individual EDG that has experienced 4 failures in the last 25 demands.
response to exceedence of a single trigger value (Section 0.2.4.2) would apply.
Followinq com>1etion of corrective actions, restored performance of the problem l0G siould be demonstrated by conducting seven consec The monthly surveillance test no more than seven days between each demand).
schedule should not be resumed on the problem EDG until the seven consecutive All starts and load runs performed during
. tests are successfully completed.this period should be included in the the EDG is operable.
This procer.s of evaluating recent demands and taking appropriate action on individual EDG experiencing recurring failures is a key element in providing reasonable assurance that EDG performance is restored to an acceptable leve 17
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3 1
i paolosure s 5-8-90 Draft
)
t manoRANDUM PORT All Project Managers t
James 9. Partlow, FSON:
Associate Director for Projects 1
Office of Nuclear Reactor Regulation RasoLoTIon or stw RIC sarETr xsses (osI) s-5s, HEDG RELIABILITr" (Generic Letter, see Encl. C) seasseT:
Baelosed is senerio Letter 80-00 which is being sent to all power It provides reactor licensees and operating license applicants.
guidance for action to implement programmatic requirements for an amargency diesel generator (EDG) reliability program that will provide an acceptable resolution to OSI 3-55 on EDG reliability.
It also provides guidance for the preparation of a license amendment request to implement line-item improvements inAny request J Technical specifications (Ts).
voluntary.
It is intended that Project Managers will review licensees commitment to programmatic requirements for monitoring and maintaining EDG reliability in accordance with the guidance in for the closure of Os1 3-55.
Generally it Generic Letter 90-00 should not be necessary to consult or to obtain review assistance from a technical review branch unless the licensee's proposed i
Also, it is action deviates from the generic letter guidance.
intended that Project Managers will review proposed license i
j amendments for changes to T8 conforming to the generic letter guidance.
that has Enclosed is a model safety Evaluation Report (sER) been prepared by the Technical specifications and the Electrical The model sER should facilitate your systems Branches.
preparation of a letter to close Os! 3-56 for the facility as well as for any proposed license amendment to implement the Because the resolution of line-item improvements in plant Ts.
Gs! B-55 permits a relaxation in Ts requirements, proposedIf you shoul changes to Ts are voluntary.
contact Tom related questions on the Generic Letter or model SER,If you have questions of a on extension 21189.
on extension 20835.
Dunning, OTsB, technical nature, contact on Chopra, SELB, The Lead Project Manager for this project is will assist you in the preparation of a MsHC prenotice for a proposed amendment conforming to the generic letter.
-~~
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L t.4.5 Post Exceedence Actions Nuclear plants exceeding one or more fatture trigger values would continue to sonitor the actual unit EDG performance versus the trigger values. 'The unit would not revert to a no exceedence status until an exceede However, before a unit could while in an exceedence, whichever occurs first. revert to a no exceede improvement actions shall be completed.
Should a unit continue in an exceedence because of new failures, these failures should be evaluated against the improvement actions previously identified for implementation. assess whether prior conclusions and ettendant act to continued failures.
9.t.4.6 Recordkeeping Utilities should retain the following information relating to the trigger values' and remedial actions in response to exceedences:
06t* on valid demands and failures that are used to calculate the (1) perforsance and reliability indicators.
The corrective actions taken in response to individual failures.
(2)
A description of the actions taken in response to a single trigger (3) exceedance.*
A description of the EDG reliability program improvements in (4) response to the 50 and 100 demand trigger exceedence.
The schedule of planned and in progress improvements.
(5)
D.R.4.7 Reporting to NRC Utilities should report EDG failures in accordance with the provis existing regulations.
The nuclear unit EDG performance and reliability indicators as compared to the appropriate 20, 50 and 100 demand trigger values.
(1)
A description of the failures, underlying causes, and corrective (2) actions taken.
18
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Basleeure G.1 5-8-90 Draft f
s mODEL ahFETY BYkLU1 TION RB2Q31 t
Underscored blank spaces are to be filled la with theThe information l applicable information.
brackets should be used as applicable on a plant-specific basis.
SAFETY EVALUATION SY TEE OFFICE OF NUCLEAR REAC RELATED TO AMENDMENT Wo. _ TO FACILITY OPERATING LIC AND AMENDMENT Wo._ TO FACILITY OPERATING LICENSE NFP i
[ UTILITY NAME)
DOCKET NOS. 50-AND 50-
~
[ PLANT NAME), UNIYS 1 AND 2 i
j J
INTRODUCTIQN 1990, [ utility name:
(the licensee) provided a response to the request for a oomahtment to implement By letter dated c.5 and C.6 of Revision 3 to Regulatory Positions c.3, c.4, Regulatory Guide 1.9, " Selection, Design, Qualificatio l
1E Onsite Electric Power systems at Nuclear Power Plants" and
" Guideline and Initiative SA and Appendix D of NUMARC 4700, Technical Bases for NUMARC Initiatives Addressing Station This request was Blackout at Light Water Reactors," Revision 1.
i made in Generic Letter 90-00, " Request for Action Pursuant to 10 Related to the Resolution of Generic Safety Issue 1990.
CFR 50.54(f)
Diesel Generator Reliability," datedproposed changes to the (GSI) 3-56,
~
In addition, the licensee specifications (Ts) for [ plant name).
The proposed changes modify the Action requirements of Ts 3.4.1.1 for performingsurveillance re emergency diesel generator (EDG)an offsite power source is inoperab related to the accelerated frequency for of Table 4.8.1.1.2-1 conducting monthly EDG surveillance requirements based on the frequency of EDG failures, and the requirements in TS 4.8.1 1.3 Guidance on the proposed for reporting EDG failures.
modifications to 78 was also provided to all licensees and operating reactor applicants by Generio Letter 90-00.
EVALUATIQM The licenses provided a commitment to comply with Regulatory Revision C.5 a_ud c.6 of Regulatory Guide l'.9, 3 for implementing programmatic requirements for monitoring and Positions c.3, c.4, i
[0.95 or 0.975, as maintaining the EDG target reliability ofas selected for compliance with th applicable)
[
3 s
s (By NRO letter dated the station 31mokout Rule (as CPR 88.63).
in
, 1990, the staff fomad that (plant amme(s)) is(are)
OR The
'soaplianos with the requiremente of the blackout rule.
staff's evaluation of complianee with the blaakeut rule for (plaat saae(s)) is ongoing.)
Bowever, based on the above response, the staff finds that the licenses has takaa appropriate action to address the resolution of Gs1 3-86 on 500 reliability for (plant.mame(s)) by the comaltanat to comply with Regulatory Positions C.3, C.4, C.5 and C.6 of Regulatory Guide 1.9 and NUMARC 8700, Revision 1.
Furthermore, this action is consistent with the need for an EDG reliability program that has the capability to achieve and maintain the target EDG reliability selected to cope with station blaskout in response to DSI A-44,
- 8tation Blackout."
The licensee bas proposed a change to Specification 4.8.1.1-to modify the Action requirements that apply when an offsite power circuit is inoperable.
This change would eliminate the
[4.8.1.1.2.a.5) A change to j
requirement to each EDG unit by TSwas proposed such that the accelerated test Table 4.8.1.1.2-1 frequency of not less than once per 7 days for conducting monthly EDG surveillance requirements would apply when the number of EDG failures, on a por EDG basis, exceeds 3 in the last 25 valid Furthermore, the abange permits the accelerated test starts.
frequency to be terminated when 7 consecutive failure-free starts have been performed provided the time interval between In addition, the consecutive tests is no less than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
criteria for determining the number of failures and number of valid tests were changed from segulatory Position C.2.e of Regulatory Guide 1.108 to Regulatory Position C.2.1 of Regulatory Guide 1.9, Revision 3.
Finally, the licensee has proposed to modify TS 4.8.1.1.3 to eliminate the special reporting requirements for all EDG failures and to include data consistent with the recomasadations of for Regulatory Position C.S of Revision 3 to Regulatory Guide 1.9 EDG failures that are reported pursuant to the requirements of 10 CFR 50.73.
These changes to the T8 for (plant name/ units) are consistent with the guidance provided in Generic Letter 90-00 and are based upon the recognition that the benefit to safety of the more restrictive existing surveillance Requirements is small in view of the benefits to safety derived from the elimination of unnecessary starting cycles for the EDG units and from the implementation of the above noted progranaatic requirements for monitoring and maintaining 200 target reliability, including the associated recordkeeping on RDG failures.
on the basis of its review of this matter, the staff finds that these changes to the TS for [ plant'name] Unit (s) is(are) acceptable.
ENVIRONMENTAL CONSIDERATION 1
i
l l
involve changes in the use of the located withis the restricted area as defined in 10 amendment (s)
This(These)
The staff has (etermined that the amendment (s) facility (iss) ificant involve se significant increase la the amounts and me sign CFR Part 30.
ff change in the types of any effluent that may be rele l or from sumulative escupational exposure.
upon the increased reliability of the BDO which wil i
and asiataining 3DO reliability and the relaxation of surveillance requirements in Ts that will have a beneficial impact on 300 reliability by reducing the number of unnecessary The staff has determined that the amendment (s) involve no significant-hasards consideration, mad there has been test eyeles.
hecordingly, the amendments no public comment on such finding. meet the eligibility criteria fo th Pursuant to 10 CFR 51.22(b), ao environmental impact statement or environmental assessment need in 10 CFR 51.22 (c) (9).
be prepared in connection with the issuance of these amendments coMcLUsION The commission's determinations that the amend l
The
~~, 1990.
) on No public Federal nacister (5 ~ FR
' Commission consulteI with the state of
_ _. _ did not have any comments were received, and the state of comments.
h taff On the basis of the considerations discussed above, t e sthere i
in and safety of the public will not be endangered by operat onsuch concludes that (1) the proposed manner, (2) the compliance with the commission's regulations, and (3) amendment f the issuance of this(these) common defense and security or to the health and public.
Thomas G. Dunning, OTSB/DOEA f
Principal contributors:
PD j DRP_,
1990 Dated:
i i_
l
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r
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2 7 - -- - -- - _ -- -- --- - -
L l
games G. Partlow Associate Digester for Projects Offise of Wuolear Roaster Regulation Baelosuress 1.
Generio Letter 90-00 (see' Bas 1. C) 3.
Model SER i
_ _ _ _ _ _ _ _ _ _. _ - _ _ _