ML20247F600

Reissued Reg Guide 1.155,Task SI 501-4, Station Blackout, Correcting Tables 1,5 & 6

ML20247F600
Person / Time
Issue date:	08/31/1988
From:	NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES)
To:
References
TASK-RE, TASK-SI-501-4 AE06-1-084, AE6-1-84, REGGD-01.155, REGGD-1.155, NUDOCS 8907270193
Download: ML20247F600 (23)

Text

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[% U.S. NUCLEAH REGULATORY COMMISSION g\) REGULATORY GUIDE

) a ..e OFFICE OF NUCLEAR REGULATORY RESEARCH Reissued to correct REGULATORY GUIDE 1.155 Tables 1, (Task $15014) 5, and 6.

STATION BLACKOUT A. INTRODUCTION this regulatory guide provides quality assurance guidance for non-safety systems and equipment used to meet the Criterion 17, " Electric Power Systems," of Appendix requirements of G $0.63.

A " General Design Criteria for Nuclear a ower Plants,"

to 10 CFR Part 50, " Domestic Licensing of Production This guide describes a riethod acceptable to the NRC and Utilization Facilities," includes a requirement that staff for complying with the Commission regulation that an onsite electric power system and an offsite electric requires nuclear power plants to be capable of coping power system be provided to permit functioning of with a station blackout for a specif4ed duration. This sttuctures, systems, and components important to safety, guide applies to all light-water-cooled nuclear power plants.

Criterion 1, " Quality Standards and Records." of -

Appendin A to 10 CFR Part 50 includes a requirement The Advisory Committee on Reactor Safeguards has for a quality assur:nce program to provide s&quate been consulted concerning this guide and has concurred assurance that structures, systems, and components in the regulatory position.

important to safety will perform their safety functions.

Any information collection activities related to this Criterion 18, " Inspection and Testing of Electric regulatory guide are contained as requirements in the Power Systems," of Appendix A to 10 CFR Part 50 revision of 10 CFR Part 50 that provides the regulatory j includes a requirement for appropriate periodic testing basis for this guide. The information collection require-(

(

and inspection of electric power systems important to safety.

ments in Part 50 have been cleared under the Office of Management and Budget Clearance No. 3150-0011.

u The Commission has amended its regulations in 10 B. DISCUSSION CFR Part 50. Paragraph (a), " Requirements," of 6 50.63,

" Loss of .All Alternating Current Power," requires that The term " station blackout" refers to the complete each light-water-cooled nuclear power plant be able to loss of alternating current electric power to the essential withstand and recover from a station blackout (i.e., and nonessential switchgear buses in a nuclear power loss of the offsite electric power system concurrent plant. Station blackout therefore involves the loss of with reactor trip and unavailability of the onsite emer- offsite power concurrent with turbice trip and failure of gency ac electric power system) of a specified duration. the onsite emergency ac power system, but not the lost Section 50.63 requires that, for the station blackout of available ac power to buses fed by station batterica duration, the plant be capable of maintaining core through inverters or the loss of power from " alternate cooling and appropriate containment integrity. It also ac sources." Station blackout and alternate ac source identifies the factors that must be considered in specify- are defined in @50.2. Becaus? many safety systems ing the station blackout duration. tequired for reactor core decay heat removal and con-t tainment heat removal are dependent on ac power, the Criteria 1 and 10 of Appendix A to 10 CFR Part 50 consequenen of a station blackout could be severe. In

} the event of a station blackout, the capability to cool

}

apply to safety-related equipment needed to cope with sta-tion blackout and other safety functions. Appendix A of the reactor core would be dependent on the availability USNRC RE'GUL/. TORY GVfDC$ The guides are issAd in the following ten b" cad divisions Reputatory Guides are issued to pescrlie and make available to the cl 4c par s of eC ml on s te i tion t de te h es are nd est Reactors . Tv p rtation n'fe?'s"#fett! 'N fio',al!*!"2"n'c '",7'EC*U'J#o'ry i I"0!r"fne'2f'aMt'r'"""

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andings to utsite It t Na eo co in$ar of a errNto Copies of issued guides may be purchased from t%e Government n

license by ttke Commission. Pr i ff e at he c er t fO tce info ti to

'

• This guide was issued afterconsideration cf cornments received from Do :uments. U.b Governrnent Printing O$f6ce, post Of f ka Box t \ ine pubuc. Comments and suggestions for arnprovements in tnese 37082. Washington, DC 20013aos2 telephone (202)275-2060 or i L guides era encouraved et all times, arid guides wiet t>e revised, as (202)275-2171.

appropriate, to accommodate comments and to reflect new informan tion or experience.

Written com*,er ts may be submitted to the Rules and Procedures tr. formation Service on a 6tanding order basis. DetaHs on this Branch. DRR. ADM, U.S. Nuclear Regulatory Commission, service may be t.otained by writing NTIS, 528$ Rort Royal noac Washington, DC 20555. Antingfield, V A 22161.

8907270193 880031 PDR RECCD 01.155 R PDR L __ _ _ . _ _ _ _ _ . _ _ _ _ _ . _ _ _

i of systems thit do not require ac power from the essential with deMgn, operational, and environmental f:ctors. Exist-and nonessential switchgear buses and on the ability to ing standards and regulatory guides include specific design restore ac power in a timely manner. criteria ;tnd guidance on the independence of preferred (offsite) power circuits (see General Design Criterion 17 The concern about station blackout arose because of " Electric Power Systems," and Section 5.1.3 of Reference the accumulated experience regarding the reliability of ac 8) and the independence of and lind!ing interactions power supplies. Many operating plants have experienced a between diesel generator units at a nuclear stetion (see total loss of offsite electric power, and more occurrences General Design Criterion 17, Regulatory Guide 1.6,"Inde-are expected in the future. In almost every one of these pendence Between Redundant Standby (Onsite) Power loss-of-offsite-power events, the onsite emer2ency ac power Sources and Between Their Distribution Systems," Regtla-i supplies have been available immediately to supply the tory Guide 1.75, " Physical Independence of Electric I

power needed by vital safety equipment. Ilowever,in some Systems," and Reference 9). In developing the recommenda-instances, one of the redundant emergencyac powersupplies tions tu this guide, the staff hasassumed that,by adhenna to .

.has been unavailable. In a few cases there has been a com- such standards, licensees have minimized, to the extent I plete loss of ac power, but dur:Ag these evr uts ac power was practical, single-point vulnerabilities in design and operat a restored in a short time without any serious consequences. that could result in a loss of all offsite power or all ons; e in addition, there have been numerousinstances when emer- emergency ac power.

gency diesel generators have failed to start and run in response to tests conducted at operating plants. Onsite einergency ac power systera unavailability can be affected by outages resultir.; from testing and main-The results of the Reactor Safety Study (Ref.1) Aowed tenance. Typically, this unavailab3ity is about 0,007 that, for one of the two plants evaluated, a station t>lackout (Reference 5), which is small compared to the minimum event could be an important contr.ibutor to tla total risk emergency diesel renerator reliability specified in Regula-from nuclear power plant accidents. Although this total risk tory Position 1.1 of this regulatory guide (i.e., 0.95 or 1 was found to be small, the relative importance of station 0.975 reliability per demand). However, in some cases 14ackout events was established. This findirg and the )

outages due to maintenance can be a significant con-accumulated diesel generator failure experience increased tributor to emergency diesel generator unavailability.

th concern about station blackout. This catribution can be kept low by having high-quality test and maintenance procedures and by scheduling regular in a Commissior, proceeding addressing station black- diesel renerator maintenance r.t times when the reactor is out, it was determined that the issue should be analyzed shut down. Also, limiting conditions for operation in the to identify preventive or mitigative messares that can or technical specifications are designed to limit the diesel should be taken. (See I'lorida Power & ljsht Company generator unavailability when the plant is operating. As

(!;t. Lucie Nucleer Power Plant, Unit No. 2) ALAB403, long as the unavailabibty due to testing and maintenance is I;l NRr 30 (1980); modified CL1-%1-12,13 hisC 638 not excessive, the maximum emergency diesel generator (1981).) failure rates for each dicscigeneratorspecifiedin Regulatory Position 1.1 would result in acceptable overall reliability for The assue of station blackout involves the likelihood the emergency ac power system.

and duration of the loss of offsite power, the redur dancy ani reliability of oneite emergency ac power systems, Based on ( 50.63, all licensres and applicants are amt the potental i for severe accident sequences after a required to assess the capability of their plants to maintain losa of all acpower. Refe ences 2 through 7 provide dete;1ed adequate core cooling and appropriate containment integrity analyses of these topics. Based on risk studies perforn ed to during a station blackout and to have procedures to cope date, the resultsindieete that estimated core melt freque ncies with such an event. This guide presents a method accept-from station blackout vary considerably for different plants able to the NRC staff for determining the specified dura-and could be a significant risk contributor for some plants. tion for which t plant should be able to withstand a station In wder to reduce this risk, action should be taken to resolve blackout in accordance with these requirements. The the safety concern stemming from station blackoi.t. The application of this method results in selecting a minimum issue is of concern for both PWRs and BWRs. acceptable station blackout duration capability from 2 to f 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />, depending on a comparison of the plant's charac- 1 This guide primarily addresses the following three teristi"s with those factors that have been identified as  ;

areas: (1) maintaining highly reliable ac electric power significantly affecting the risk from station blackout. These systems, (2) developing procedures and training to testore factors include redundancy of the onsite emergency ac offsite and onsite emergency ac power should eitber one or pcwer system (i.e., the number of diesel generators available both become unavailable, and (3) ensuring that plants can for decay heat ren oval minus the number needed for decay cope with a station blackout for mome, period of time based heat removal), the reliability of onsite emergency ac power on the probability of occurrence of a station blackout at a sources (e.g., diesel generators), tne frequency of loss of site as well as the capability for restoring ac power in a offsite power, and th; p70bable time to restore offsite timely fashion for that wite. powet One factor that affe, cts ac power system reliability Licensees may propose durations different from those is the vulnerability to common cruse failures associated specified in this guide. The basis for alternative durations 1.155-2

I would be predicated on plant-specific factors relating to the Diesel Generators at 'U.S. Nuclear Power Plants" l reliability of ac power systems such as those discussed in (Ref. I1), or equivalent.1 bh Reference 2.

(' The information submitted to comply Mth @ 50.63

2. Calculate the nuclear unit " average" EDG reliability for the last 20, 50, and 100 demands by averaging is also required to be incorporated in an update to the the results from step 1 above.

FSAR in accordance with paragraph 50.71(c)(4). It is expected that the applicant or licensee will have available 3. Compare the calculated " average" nuclear unit for review, as required, the analyses and related informa- EDG reliability from step 2 above against the tion suppot ting the submittal. following criteria: 9 i

Concurrent with the development of this regulatory Last 20 demands > 0.90 reliability )

guide, and consistent with discussions with the NRC Last $0 demands > 0.94 reliability I staff, the Nuclear Management and Resource Council Last tC0 demands > 0.95 reliability  !

(NUMARC) has developed guidelines arid procedures for essessing station blackout coping capability and duration 4. If the EAC group is A, B, or C AND any of the for light water reactors (nub! ARC-8700, Ref.10). The three evaluation criteria in step 3 are met, the NRC staff has reviewed these guidelines and analysis nuclear unit may select an EDG reliability target methods and ccmcludes that NUMARC-6700 provides of either 0.95 or 0.975 for determining the appli-guidance for conformance to @ 50 63 that is in large cabk coping daration from Table 2.

part identical to the guidance provided in this regulatory guide. Table I cf this regulatory guide provides a section- If the EAC group is D and any of the three by-sectioa comparison between Regulatory Guide 1.155 evaluation criteria in step 3 are met, the allowed and NUM ARC-8700. The use of NUMARC-8700 is EDG reliability target is 0.975.

further discussed in Section C, Regulatory Position, of j this guide. 5. If the EAC group is A, B, or C and NONE of the selection criteria in step 3 are met, an EDG C. R2GULATORY POSITION reliabdity level of 0.95 must be used for determin-ing the applicable coping duration from Table 2.

~

This regulatory guide describes a means acceptable Additionally, if the " averaged" cuclear unit EDG

\ to the NRC staff for meeting the requirements of reliability is less than 0.90 based on the last 20 cemands, the acceptability of a coping duration l \V) j e@.50.63 iso ofprovides 10 CFP Part 50. NUMARC-8700 (Ref.10) guidance acceptaUe to the staff basedforonmeet-an EDG reliability of 0.95 from Table 2 ing these requirements. Table 1 provides a cross-reference must be furtherjustified.

to NUMARC-8700 and notes where the regulatory guide takes precedence. If the EAC group is D and NONE of the three evaluation criteria in step 3 are met, the required

1. ONSITE EMERGENCY AC POWER SOURCES coping duration (derived by using Table 2) should (EMERGENCY DIESEL GENERATORS) be increased to the next highest enring level (i.e.,

4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> to R hours,8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> to 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br />).

1.1 Emergency Dieal Generator Target Reliability Levels i 1.2 Reliability Program The minimum emergency diesel generator (EDG)

! reliability should be targeted at 0.95 per demand for The reliable operation of onsite emergency ac power each EDG for plants in emergency ac (EAC) Groups A, sources should be ensured by a reliability program B, and C and at 0.975 per demand for each EDG for designed to maintain and monitor the reliability Jevel plants in EAC Group D (see Table 2). These reliability of each power source over time for assurance that the f levels wi2 be considered minimum target reliabilities and selected reliability levels are being achieved. An EDG l each plant should have an EDG reliability program reliability program would typically be compo'ed s of the containing the principal elements, or their equivalent, following elements or activities (or their equivalent):

outline d in Regulatery Position 1.2. Plants that select a target EDG reliability of 0.975 will use the higher level 1. Individual EDG reliability target levels consistent as the target in their EDG reliability programs. with the plant category and coping duration selected from Table 2.

The FDG reliabiEty for determining the coping duration for a station blackout will be determined as 2. Surveillance testing and reliability monitoring feliows. programs designed to track EDG performance and to support maintenance activities.

1. CsIculate the most recent EDG reliability for c -

[G J

each EDG based c,n the last 20, 50, and 100 *This EDG relisbliny is not suitable for probabilistic risk

( demands using definitions and methodology in Section 2 of NSAC-108, " Reliability of Emergency 7p*y*l,a , ,f,oljg n s)*# N nt is for such probabilistIc ribu1r th gb w analyses.

eau ot uls be a c bl!

1.155-3 l

1 - - - - - - - - - - - - - - - - - - - -

i

3. A maintenance prograta that ensures that the the probability of a station blackout at the site as target BDG reliability is being schieved and that well as the capability for restoring ac power for that provider, a capability for failure analysis and site. Each nuclear power plant has the capability to root-cause investigations, remove decay heat and maintain appropriate containment inte,r,rity without ac power for a liraited period of time.

4. An information and data collection system that Regulatory Position 3.2 provides guidance for determining services the elements of the reliability program and the length of time that a plant is actually able to cope that monitors achieved E0G reliability levels with a station blackout. If the plant's actual station against target values. blackout capability is significantly less than the accept-able minimum duration, modifications may be necessary S. Identified responsibilities for the major program to extend the plant's ability to cope with a station elements and a management overr,ight program for blackout. Should plant modifications be riecessary, reviewing reliability levels being achieved and Regulatory Position 3.3 provides guidane on making i' ensuring that the program is functioning properly, such modifications. Whether or not modifications are necessary, procedures and training for station blackout 1.3 Procedures for Restoring Emergency AC Power events should be provided according to the guidance in Regulatory Position 3.4.

Guidelines and procedures for actions to restore emergency ac power when the emergency ac power 3.1 Minimum Acceptable Station Eckout Duration system is unavailable should be integrated with plant- Capability specific technical guidelines and emergency operatsg procedures developed uting ti:e emergency operating Each nuclear power plant should be able to withstand procedure upgrade program estataished ir response to and recover from a station blackout lasting a specified Supplement 1, " Requirements for Emergtney Response minimum daration. The specified duration of station Capability" (Generic Letter No. 82-33,f '.o NUREG-0737, blackout should be based on the following factors:

" Clarification of TMI Action Plan Requirenants" (Ref.12). 1. The redundancy of the onsite emergency ac power system (i.e., the number of power sources

2. ' . FSITE POWER available minus the nuraber needed for decay heat Procedures should include tne actions necessary to restere offsite power and use nearby power sourcesa 2. The reliability of each of the onsite emergency ac when offsite power is unavailable. As a tvirdmum, the power sources (e.g., diesel generator),

following potential causes for loss of offsite power should be considered: 3. The expected frequency of loss of offsite power, and

. Grid undervoltage and collapse

. Weather-induced power loss 4. The probable time needed to restore offsite power.

. Preferred power distribution system faults 4 that could result in the loss of norma.! power to essen- A method for determining an acceptable lainimum tial switchgear buses station blackout duration capability as a factirsn of the above site- and plant-2 elated characteristics i: given

3. ABILITY TO COPE WITH A STATION BLACKOUT in Table 2. Tables 3 throegh 8 provide the necessary detailed descript ons and definitions of the various The ability to cope with a station blackovt for a factors used in Tchle 2. Table 3 identifies different levels certain time provides additional ' defense-in-depth should of redundancy of the onsite emergency ac power system both offsite and onsite emergency ac power systems fail used to define the emergency ac powet confit,uration concurrently. Regulatory Position 3.1 provides a method groups in Table 2. Tribde 4 provides definiaons of the (

to determine an acceptable minimum time that a plant three offsite power design characteristic r,roups used in should be able to, cope. with a stati_on .blackoutbased_ on Table 2. The groups are defined according to various 2 combinations of the following factors: (1) independence <

Modifications or additior,s to deal to witheneric technical a station guide-blackout for of offsite power (1), (2) scytre weather (SW), (3) severe lines that are in t$[eYtant 'Nif1c p necessar[S c n ca !I$" 's a INe$1ne "8 as 7equYeSt t r (SWR), and (4) extremely severe weather recovery u lement 1 weather (ESW). The definitica.s of the factors I, SW, to N UREG-0737

• {Ref.12)

'e p M and t noutlined in E gn er-SWR, and ESW are provided in Tables 5 through 8, gencyNe!a'tbeYr edIrN 'kRef.'13).

j respectively. After i;tentifying the appropriate groups 3

this includes such items as nearby or c asite ses turbine from Tables 3 and 4 and the reliability level of the

" #' ' h ' 8' "' "' ""

b$ack2 tart'fossis pYEer"p*la [ts. "' onsite emergency ac power sources (determined in accor-dance with Regulatory Position 1.1), Table 2 can be were includes such failures as the distribution system hard-t cl ing and maintenance errors, and lightning-used to determine the acceptable minimum station 1

l 1.155-4

3.2 Evaluation cf Plant Specific Station Blackout environments if an assessment has been performed that Capability provides reasonable assurance that the required equip-n ment will remain operable.

I \

Each nuclear power plant should be evaluated to

( determine its capability to withstand and recover from a station blackout of the acceptable duration determined 3.2.5. Consideration should be given to using available non-safety-related equipment, as well as safety-related )

for that plant (see Regulatory Position 3.1). The follow- equipment, to cope with a station blackout provided '

ing considerations should be included when determining such equipment meets the recommendations of Regula-the plant's capability to cope with a rtation blackout. tory Positions 3.3.3 and 3.3.4 Onsite or nearby alternate ac (AAC) power sources that are independen' and 3.2.1. The evaluation should be performed assuming diverse from the normal Class IE emergency ac power that the station blackout event occurs while the reactor sources (e.g., gas turbine, separate diesel er:pne, steam is operating at 100% rated thermal power and has been supplies) will constitute an acceptable station blackout at this power level for at least 100 days. coping capability proYided an analysis is performed that demonstrates the plant lias this capability from the 3.2.2. The capabilay of all systems and components onset of station blackout until the AAC power source necessary to provide core cooling and decay heat or sources are started and lined up to operaie all equip-removal following a station blackout should be deter- ment necessary to cope with station bidout for the mined, including station battery capacity, condensste required duration.

storage tank capacity, compressed air capacity, and instrumentation and control requirements. In general, equipment req 2 ired to cope with a station blackout during the first 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> should be available on 3.2.3. The ability to maintain adequate reactor the site. For equipment not located on the site, consid-coolant system inventory to ensure that the core is eration should be given to its availability ned accessibility I coole3 should be evaluated, taking into consideration in the time required, including consideration of weather l shrinkage, leakage from pump seals, and inventory loss conditions likely to prevail during a loss of offsite from letdown or other normally open lines dependent power.

on ac power for isolation.

If the AAC source or sources meet the recommenda-3.2.4. The design adequacy and capability of equip- tions of Section 3.3.5 and can be demonstrated by test g ment needed to cope with a station blackoui for the to be available to power the shutdown buses within 10

/ minutes of the onset cf station blackout, no coping

()) required and evaluated duration as appropriateand for recovery the associated peJiod envircn-shouldanalysis beis addresced required.

menta: conditions. This should include consideration as appro, atr of the following: 3.2.6. Consideration should be given to timely opera-tor actions inside or outs de the control room that

1. Potential failures of equipment necessary to cope would increase the length of time that the plant can l

with the station blackout, cope with a station blackout provided 2t can be demon-strated that these actions can be carried out in a timely

2. Potentird emtonmental effects on the operability fashion. For example, if station battery capacity is a

• nd reliability of equipment necessary to cope limiting factor in coping with a station blackout, shed-with the station bierkout, including possible ding nonessential loads on the batteries could extend effvets of fire protection systems, the time until the battery is depleted. If load shedding or other operator actions are considered, corresponding

3. Potential effects of other hazards, such as weather, procedures should be inc9tporated into the plant-specific on station blackout re .ponse equipment (e. g. , technical guidelines and emergency operating procedures.

auxiliary equipment to operate onsite buses or to 9

recover EDGs and other equipment as needed), 3.2.7. The ability to maintain " appropriate contain-ment integrity" should be addressed. " Appropriate

4. Potential habitat >ility concerns fm those areas that containment integrity" for station blackout means that would require cperator access during the station adequate containment integrity is ensured by providing blackout and recovery period. the capability, independent of the preferred and blacked-out unit's onsite emergency ac power supplies, for valve Faaluations tl.at have already been performed need position indication and closure for containment isolation not be duplicated. For examph if safety.related equip- valves that may be in the open position at the onset of ment required during a total loss of ac power has been a station blackout. The following valves are exchufed qualified to operate under environmental conditions from consideration:

exceeding those expected under a statior. blackout (e.g.,

joss of heating, votilation, and air conditioning), addi- 1. Valves normally locked closed during operation, tional analyses need not be performed. Equipment will be considered acceptable for station blackout temperature 2. Valves that fail closed on a loss of power, 1.155-5

3. Check valves, other means of control are required, it should be demonstrated that these steps can be carried out

4. Valves in nonradioactive closed-loop systems not in a time!y fashion, and expected to be breached in a station blackout  ;

(this does not include lines that communicate 2. If the system must operate within 10 minutes of a j directly with containment atmosphere), and loss of all ac power, it should be capable of being actuated from the control room.

5. Valves of less than 3-inch necninal diameter.

3.3.$. If an AAC power source is selected specifically  ;

3.3 Modifications To Cope with Station Blackout for satisfying the requirements for station blackot.t, the {

design should meet the following criteria:

If the plant's station blackout capability, as deter- .

mined according to the guidance in Krgulatory Position 1. The AAC power source should not normally 3.2, is significantly less than tpe m!Aimum acceptable be directly connected to the' preferred or the l p10nt4pecific station bhckout durdion (as developed blacked-out unit's onsite emergency ac power cccording to Regulatory Position 7 I or as justified by system.

the licensee or applicant ot " m other basis and ,;,

cccepted by the staff), modificMrs to the plant anay 2. There should be a minimum potential ;for common be necessary to extend the time sne plant is able to cause failure with the preferred or the b{a,9ked-out cope with a station blackout. If modifications are unit's onsite emergency ac power sources. No aceded, the following items should be considered: single-point vulnerability should exist whereby a weather-related event or single active failure could 3.3.1. If, a'ter considering load shedding to extend disable any portion of the blacked-out unit's onsite the time until battery depletion, battery capacity must emergency ac power sources or the preferred power be ex tended further to meet the station blackout dura- sources and simultaneously fa.il the AAG power tion recommended in Regulatory Position 3.1, it is source.

considered acceptable either to add batteries or to add a charging system for the existing batteries that as inde- 3. The AAC power source should be available in a pendent of both the offsite and the blacked-out unit's timely manner after the onset of station blackout onsite emergency ac power systems, such as a dedicated and have provisions to be manually connected to diesel generator, one or all of the redundant safety buses as required. ,

The time required for making this equipment i 3.3.2. If the capacity of the condensate storage tank available should not be more than I hour as is not suffkient to remove decay heat for the station demonstrated by test. If the AAC power source blackout duration reconunended in . Regulatory Position 3.1, can be demuustrated by test to be available to a system meeting the requirements of Regulatory Posi- power the shutdown buses within 10 minutes of tion 3.5 to resupply the tank from an alternative water the onset ci station blackout, no coping analysis

. source is an acceptable means to increase its capacity is required.

provided any power source necessary to provide addi-tional water is independent of both the offsite and the 4. The AAC power source should have sufficient blacked-out unit's onsite emergency ac puer systems. capacity to operate the systems necessary for coping with a station blackout for the time required 3.3.3. If the compressed air capacity is not sufficient to bring and maintain the plant in safe shutdown.

to re nove decay heat and to maintain appropriate containment integrity for the station blackout duration 5. The AAC power system should be inspected, recommended in Regulatory Position 3.1, a system to maintained, and tested periodically to demonstrate provide sufficient capacity from an alternative source operability and reliability. The reliability of the that meets Regu.atory Position 3.5 is an acceptable AAC power system should meet or exceed 95 per-means to increase the air capacity prorided any power cent as determined in accordance with NSAC-108 source necessary te provide additional an is independent (Ref.11) or equivalent methodology.

of both the offsite and the blacked-out unit's onsite <

emergency ac powrr systems. An AAC power source serving a multiple-unit site where onsite emergency ac sources are not shared 3.3.4. If a system is required for primary coolant between units should have, as a minimum, the capacity chcrging and makeup, reactor coolant pump seal cooling and capability for coping with station blackout in any or injection, decay heat remcyal, or maintaining appro- of the units.

priate containment integrity specifically to meet the station blackout duration recommended in Regulatory At sites where onsite emergency sources are shared Position 3.1, the following criteria should be met: between units, the AAC power sources should have the capacity and capability to ensure that all units can be

1. The system should be capable of being actuated brought to and maintained in safe shutdown (i.e., those Jad controlled from the control room, or if plant conditions defined in plant technical specifications 1.155-6

r;s llot Standby or liot Shutdown, as appropriate). Pikats Position 3.1 and to restore normallong-term core cooling /

have the option of snaintaining the RCS at normal decay heat removal once ac power is restored.

operating temperatures or at reduced temperatures.

[ 3.5 Quality Assurance and Specification Guidance for l (' Plants that have more than the required redundancy Station Blackout Equipment That Is Not Safety-of emergency ac sources for loss.of-ofr site-power condi- Related tions, on a per nuclear unit basis, snay use one of the existinr, ernergency sources as an AAC power source Appendices A and B provide guidance an quality assurance l pravided it meets the applicable criteria for an AAC (QA) activities and specifications respectively for non-safety- '

sourcs. Additionally, emergency diesel generators with related equipment used to meet the requirements of @ $0.63 1-out-of 2-shaud and 2-out-of-3-shared ac power configura- and not already covered by existing QA requirements in tons may not be used as AAC power sources. AppendixB or R of Part S0. Appropriate activities should be implemented from among those listed in these appen-3.3.6. If a system or component is added specifically dices depending on whether the non-safety equipment is to meet the recommendations on station blackout being added (new) in is existing. This QA guidance is duration in Regulatory Position 3.1, system walk downs applicable to non%fety systems and equipment for meet-and initial tests of new or modified + systems or critical ing the requirements of 'Q 50.63 of 10 CFR Part 50.

components should be performed to verify that the The guidance on QA and specifications incorporates a modifications were performed properly. Failures of lesser degree of stringency by eliminating requirements for

added components that may be vulnerable to internal or involvement of parties outsie the rx,rmalline organization.

external hazards within the design basis (e.g., seismic NRC inspections will focu on the implementation and

events) should not affect the operation of systems effectiveness of the quality controls described in Appen-required for the design basis accident. dices A and B. Additionally, the equipment installed to meet the station blackout rule must be implemented 3.3 7. A- system or component added specifically to such that it does not degrade the existing safety-related meet the recommendations on station blackout duration systems. This is to be accomplished by making the non-in Regulatoty Position 3.1 should be inspected, main- safety-related equipment as independent as practicable tained, and tested periodically to demonstrate equipment from existing safety-related systems. The non-sefety operability and reliability, systems identified in Appendix B are acceptable to the NRC staff for responding to a station blackout 3.4 Procedures and Training To Cope with Station O Blackout D. IMPLEMENTATION l

Procedures 5 and training should include all operator The purpose of this section is to provide information acticas necessary to cope with a station blackout for at to applicants and licensees regarding the NRC staff's plans least the duration determined according to Regulatory for using this regulatory guide. Except in those cases in

! which the applicant or licensee proposes an acceptable

) __ alternative method for complying with specified portions

's Procedures should be intestated wit h plant specifle of the Commision's regulations, the method described in tschnical guidelines and eguersency operatins procedures this guide may be used in the evaluation of submittah by P'8

• tl applit. ants for construction permits and operating licenses d,','N'N,y bURI 0737 8'"(8h,bm (Ref.12). The E'b*"*h b*e'*s"portion task analysis N #h**d en te u$

of the (as appropriate) and will be used to evaluate licensees who In"cIull'e"Ei an8y'sNf'in {r'unYe'ntUio'n sdee'uTfdurty are required to comply with @ 50.63, " Loss of All Alter-station t>lackout. nating Current Power," of 10 CFR Part 50, 9

4

(

w 1.155-7 u_.____ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

TABLE 1 i

CROSS-REFERENCE BETWEEN REGULATORY GUIDE 1.155 AND NUMARC 8700 l-Regulatory Position in R.G.1.155 Section in NUMARC 8700 1.1 3.2.3, 3.2.4 1.2 Appendix D 1.3 4.2.1, 4.3.1 2 4.2.2, 4.3.2 -

3.1 3

.:* 2.2.1, 2.2.2 o

3.2.2 2.9, 7.2.1, 7.2.2, 7.2.3 3.2.3 2.5 3.2.4 2.7, 4.2.1, 4.2.2, 7.2.4, Appendices E and F 3.2.5 7.1.1, 7.1.2, Appendices B and C

'.2.6

.:, 4.2.1, 4.3.1, 7.2.1, 7.2.2, 7.2.3 3.2.7 2.10,7.2.5 3.3.1 7.2.2 3.3.2 7.2.1 3.3.3 7.2.3 3.3.4 2.5 3.3.5 23.1,7.1.1,7.1.2, Appendices A.

B, and C 3.3.6 None (Use Regulatory Guide 1.155) 3.3.7 4.2.l(12),4.3.l(.12), Appendices A i and B 3.4 4 3.5 None (Use Regulatory Guide 1.155)

Appendix A None (Use Regulatory Guide 1.155)

Appendix B None (Use Regulatory Guide 1.155 1.155-8

l~ \

i

[O ,

TABLE 2

. ACCEPTABLE STATION BLACKOUT DURATION CAPABILITY (HOURS)*

D Emergency AC Power Configuration Group A B C' D Unit " Average" EDG Reliability C l Offsite Power Design 0.975- 0.95 0.975 0.95 0.975 0.95 0.975  !

Characteristic Group  ;

l 2 2 4 4 4- 4 4 P1 4 4 4 4 4 8 8 j P2 P3 4 8 4 8 8 16 8-l aVariations from thcae times will be considered by the staffif justification, including a cost-benefit analysis,is provided by the licensee. The methodology and sensitivity studies presented in NUREG-1032 (Ref. 2) are acceptable for use in this justification, b See Table 3 to determine emergency ac power configuration group.

'See Regulatory Position 1.1.

d See Table 4 to determine groups P1, P2, and P3.

I i

1.155 9

TABLE 3 EMERGENCY AC POWER CONFIGURATION GROUPSa EAC Power Number of EAC Power Sources l Configuration Required To Operate AC-Powered l Group Number Power of E4C Sources Decay IIcat Removal Systems c A d 3 1 4 'l B 4 2 5 2 C d 2 3 3' 1 D 2 I 1 3 2 4 3 5 3 aSpecial-purpose dedicated diesel generators, such as those associated with high-pressure core spray systems at some BWRs, are not counted in the determination of EAC power configuration groups.

D If any of the EAC power sources are shared among units at a multi-unit site, this is the total numter of shared and dedicated sources for those units at the site, cThis number is based on all the ac loads required to remove decay heat (including u-powered decay heat ternoval systems) to achieve and maintain safe shutdown at all units at the site with offsite power unavailable, d

Foir EAC power sources not shared with other units.

'For EAC power sources shared with another unit at a tralti-unit site.

I For shared EAC power sources in which each diesel generator is capable of providing ac power to more than one unit at a site concurrently.

C O

1.155-10

s,

-~s.

TABLE 4

~( v ).

OFFSITE POWER DESIGN CHARACTERISTIC GROUPS Group Offsite Power Design Characteristics Sites that have any combination of the following factors:

ESW d l

l 1* SW b E% R C

P1 1 or 2 1 or 2 1 or 2 1 or 2 l or 2 1 l or 2 3  :

\ 1 or 2 l or 2 3 1 P2 All other sites not in P1 or P3.

l Sites that expect to experience a totalloss of offsite power

[

caused by grid failures at a frequency equal to or greater than once in 20 site-years, unless the site has procedures to recover l

s ac power from reliable alternative (nonemergency) ac power j sources within approximately one-half hour following a grid

failure.

(

k or Sites that have any combination of the following factors:

E s

SW SWR ESW i

f 0 k (O #

P3 1 Any I 5 2 Any ESW Any 1 1,2,3, or 4 1 oi 2 5 Anyl 5 1 Any ESW AnyI 4 2 1,2,3, or 4 1 or 2 3 2 4 3 3 2 3 or 4 aSee Table 5 for definitions of independence of offsite power (1) groups.

b See Table 6 for definitions of severe weather (SW) groups.

CSee Table 7 for definitions of severe weather recovery (SWR) groups.

d See Tabic 8 for definitions of extremely severe weather (ESW) grepps.

4

-r 1.155-11

TABLE S DEFINITIONS OF INDEPENDENCE OF OFFSITE POWER GROUPS j Category I l i 1 2 3

- i

1. All offsite power sources are 1.a. All offsite power sources are connected to the  !

connected to the plant plant through one switchyard. .

through two or more j switchyards or separate OR i incoming transmission 1, Independence of offsite lines, but at least one of 1.b. All offsite power sources are connected to the e power sources 4 the ac sources is electrically plant throagh two or more switchyards, and independent of the others, the switchyards are electrically connected.

(The independent 69-kV (The 345- and 138-kV switchyards in Figures line in Figure 1 is 2 and 3 represent this design feature.)

representative of this design feature.)

OR AND AND w

2. Automatic and manual 2.a. Afterloss of the norrna! ac 2.a. After loss of the normal 2.a. If the normal transfer schemes for the source, ac power source, there is source of ac Class IE buses when the an automatic transfer of power fails, there normalsource of ac power (1) There is an automatic all safe-shutdown buses are no automatic fails and when the back- transfer of all safe- to one preferred alter- transfers and up sources of offsite shutdown huses to nate power source. If one or more power f ail. a separate preferred this source fails, there manual transfers alternate power source. may be one or more of all safe-shut-

a. The normal source of manual transfers of down buses  ;

ac power is assumed (2) There is an automatic power source to the to preferred or to be the unit main 4 transfer of all safe- remaining preferred alternate off-generator. shutdown buses to one or alternate offsite site power preferred power so.rce. power sources. sources if rius preferred power source fails, there is OR another automatic transfer to the There is one auto-remaining ratic transfer preferred power and no manual sources or to alter- transfer of all nate offsite power safe-shutdown source. buses to one preferred or orte alternate offsite power source. o OR OR

b. If the Class IE buses 2.b. Each safe-shutdown bus is 2.b. The safe-shutdown buses are normally aligned are normally designed ncrmally connected to a to the same preferred power source with to be connected to the sep?Inte preferred alter- either an automatic or manual transfer to the pteferred or alternate nate power source with remaining preferred or alternate ac power power sources. 4 automatic or manual source, transfer capebility between the preferred or alternate sources.

O 1.155-12

TABLE 6 DEFINITIONS OF SEVERE WEATHER (SW) GROUPS Estimated Frequency of Loss of Offske Power Due to SW Group Severe Weather, f(per Site Yen)*

I f < 3.3 x 10'3 2 3.3 x 10'3 <f< 1 x 10-2

, 3 1 x 10-2 I f < 3.3 x 10-2 4 3.3 x 10-2 If< 1 x 10'I 5 1 x 10'I 3f

• The estimated frequency u of offsite power due to severe weather, f,is determined by the following eys ,ma:

4 f = (1.3 x 10 )h + 3 (b)h + 2 (0.012)a3 + (c)h4 where h = annual expectation of snowfall for the site,in inches 3

h = annual expectation of tornadoes (with wind speeds greater than 2

or equal to 113 rniles per hour) per square mile at the site b = 12.5 for sites with transmission lines on two or more rights-of-way spreading out in different directions from the switch-yard, or b = 72.3 for sites with transmissiori lines on one right of-way h annual expectation of storms at the site with wind velocities 3 = between 75 and 124 mph h4= annual expectation of hurricanes at the site c = 0 if switchyard h not vulnerable to the effects of salt spray c = 0.78 if switchyard fr vulnerable to the effects of salt spray The annual expectation of snowfall, to.nadoes, and storms may be obtained fron National Weather Service data from the weather station nearest to the plant or by interpolaHon, if appropriate, between nearby weather stations.

The basis for the empirical equation for the frequency of !oss of oftsite pcwer due to severe weather,I,is given in Appendix A to Reference 2.

.h p

l.155-13

~M

- - - - - - - a___ . _ _ __ _ _ _ _ _ _ . _ _ _ . _ _ _ _ _ _ _ _ _ _ . , _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _____ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ , _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

TABLE 7 DEFIN3TIONS OF SEVERE WEATHER RECOVERY (SWR) GROUPS SWR Croup Definition 1 Sites with enhanced recovery (i.e., sites that have the capability and procedures fer restor-ing offsite (nanemet.oency) ac power to the site within 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> following a low of offsite power due to severe weather).

2 Sites without eenhanced recovery.

\

\

.I TABLE 8 DEFINITIONS OF EXTREMELY SEVERE WEATHE R (ESW) GROUPS Annual expectation of storms at a site with wind velocities equal to or greater than 125 miles per ESW Group hour (e)*

1 e c 3.3 x 104 2 3.3 x 10~4 s e < 1 x 10-3 3 .1 x 10'3 < e < 3.3 x 10-3 4 3.3 x 10-3 s e < 1 x 10~2 5 1 x 10-2 g,

• The annual expectation of stonns inay be obtained from National Weather Service data from the wer.ther station nearest to the plant or by interpola-tion,if appropriate, between nearby weather stations.

O 1.155-14

. _ 2

f R

A jL h h b 69 kV 161 kV 345 kV a >

-- 4 AMAAMA LAM N/A MM

' N M%MM #%MM AUT ygAN ER MAIN _ _ _ _ _ _ _ ,

GENERATOR y U y y AUTOMATIC p p NC NC NO NO TRANSFER CLASS 10 NONSAFETY CLASS 1E NONSAFETY h

I AUTOMATIC TRANSFER I

_f J

(_ AUTOMATIC TRANSFER _ j Figure 1. Senematic Diagram of Electrically Independent Transmission Line M

1.155-15

h al h n n h a a h I. T l E 345 kV 138 kV g

E A%A%

A%AM AMMA A%4% A%#4 AAAA AAh%

y p U U Ut NC NC NONSAFETY NO NONSAFETY NO MAIN CLASSTE CLASS IE CLASS 1E CLASS 1E CENERATOR DIVISION 1 DIVISION 2 DIVISION 1 DIVISION 2

! 8 A 4 l L _ _ tv.Io_u^T'iT.a^"5LER, , ,

,,,,,,,__J

(,,, AUTOMATIC TRANSFER .__j Figure 2. Schematic Diagram of Two Switchyards Electrically Connected (One-Unit Site) n h d a h 500 kV $a 230 kV i::

3:

.+*

MM p I

'f MMMM MM MM MM MM MMMM GENERATOR 2 U V U U V U U U NC NC NC TO NC TO NC TO NC TO NC NC GENERATOR 1 NONSAFETY SOME SOME SOME SOME NONSAFETY UNIT 2 UNIT 2 UNIT 2 UNIT 1 UNIT 1 UNIT 1 CLASS th CLASS 1E CLASS 1E CLASS 1E BUSES, BUSES. BUSES, BUSES, NO TO 140 TO NO TO NO TO OTHERS OTHERS OTHERS OTHERS Figure 3. Schematic Diagram of Two Switchyards Electrically Connected (Two-Unit Site) 9 1,155-16

REFERENCES

( 4

1. U.S. Nuclear Rerulatory Coenission, " Reactor 8. Institute of Electrical and Electronics Ecgineers, 3afety Study," WASil-1400, October 1975.1 "IEEE Standard for Preferred Power Supply for Nuclear Power Generating Stations," IEEE Std

2. U.S. Nuclear Regulatory Commission," Evaluation of 765-1983, June 1983.2 Station Blackout Accidents at Nuclear Power Plants, Technical Findings Related to Unresolved Safety 9. Institute of Electrical and Electronics Engineers,  !

Issue A-44," NUREG-1032, June 1988.2 "lEEE Standard Criteria for Diesel-Generator Units Applied as Standby Power Supplies for Nuclear Power Generating Stations," IEEE Std 387-1984.

3. A. M. Rubin, " Regulatory /Backfit Analysis for the June 1984.2 Resolution of Unresolved Safety issue A-44, Station Blackout, U.S. Nuclear Regulatory Commission, 10. Nuclear Management and Resources Council," Guide-NUREG-1109, June 1988.I lines and Technical Bases for NUMARC Initiatives Addressing Station Blackout at Light Water Reactors,"

4. U.S. Nuclear Regulatory Commission, " Collection NUMARC-8700, November 1987.3 and Evaluation of Complete and Partial Losses of Offsite Power at Nuclear Power Plants," NUREG/ 11. Electric Power Research Institute, " Reliability of CR 3992 (ORNL/Tm-9384), February 1985.1 E3nergeey Diesel Generators at U.S. Nuclear Power Plants," NSAC-108, September 1986.4

5. U.S. Nuclear Regulatory Commission, " Reliability of Emergency AC Power System at Nuclear Power 12. U.S. Nuclear Regulatory Commission,"Clarif cation of Plants," NUREG/CR 2989 (ORNL/TM-8545), July TM1 Action Plan Requirements: Requirements for 1983.1 Eraergency Response Capability" (Generic Lciter 82-33), Supplement I to NUREG-0737, January 1983.1

6. U.S. Nuclear Regulatory Commission, " Emergency Diesel Generator Operating Experience, 1981 1983," 13. U.S. Nuclear Regulatory Commission, " Guidelines for NUREG/CR-4347 (ORNL/TM-9739), December 1985.1 the Preparation of Emergency Operating Procedures,"

NUREG-0899, August 1982.1

7. U.S. Nuclear Regulatory Commission,"Statwn Black-out Accident Analyses (Part of NRC Task Action 2 Plan A-44)," NUREG/CR-3226 (SAND 82-2450), May b' " "

and$#e r'oE'cI In ine'ers'sc$vi ei*eNe'N, NS boes**['n",

19e 3.1 P.0, Box 1331, Piscatawar, NJ 0885 5.

3 Copies may be obtained from the Nuclear Manasement

- and Resources Council,1776 Eye Street NW.,W ashington.

I NRC publications may be obtained frons the S er DC 20006.

intendent of Documents, U.S. Government Printing Obce. ,

4 Post Office Box 37082, Y(ashington, DC 20013 7082; or Copies may be obtained from the Electric Power fro m the National Technical Information Service, Spring. Research Institute, Research Reports Center, P.O. Ilox field, V A 2 2161. 50490, Palo Alto, C A 94303.

1.155-17

- - _ - _ - _ - _ - - - _ _ - - _ _ _ - - - - - - - - - - = - - - - - - - - - -

APPENDIX A QUALITY ASSURANCE GUICANCE FOR NON SAFETY SYSTEMS AND EQUIPMENT The QA guidance provided here is applicable to non- tion drawings and test procedures for accomplishing the safety systems and equipment used to meet the requirements activities.

l of G 50.63 and not alrerdy explicitly covered by existing QA requirements in 10 CFR Part 50 in Appendix B or R.

F. Testing and Test Control Additionally, non safety equipment installed to meet the station blackout rule must be implemented so that it does A test program should be established and implemented not degrade the existing safety-related systems. This is to ensure that testing is performed and verified by inspec-accomplished by making the nonsafety equipment as tion and audit to demonstrate conformance with design

, independent as practicable from existing safety-related and system readiness requirements. The tests should be systems. The guidance provided in this section outlines an performed in accordance with written test procedures; test acceptable QA program for non-safety equipment used for results should be properly evaluated and acted on.

meeting the station blackout rule and not already covered by existing QA requirements. Activities should be imple- 6. Inspection, Test, and Operating Status mented from this section as appropriate, depending on whether the equipment is being added (new) oris existing. Measures should be established to identify items that have satisfactorily passed required tests and inspections.

1. Design Control and Procurement Document Control

7. NonconformingItems Measures shoul( be established to ensure th.at all design-related guidelines used in complying with 6 50.63 are Measures should be established to control items that do included in design and procurement docunn .ts, and not conform to specified requirements to prevent inadvertent that deviations thereham are controlled. use or installation.

2. Instructions,Procedu:es,and Drawings 8. Corrective Action Inspections, tests, administrative controls, and training Measures should be established to ensure that failures, necessary for compliance with Q 50.63 should be prescribed malfunctions, deficiencies, deviations, defective components, by documented instructions, procedures, and drawings and and nonconformances are promptly identified, reported, should be accomplished in accordance with these documents, and corrected.

3. Control of Purchased Material, Equipment, and Services 9. Records Measures should be established to ensure that purchased Records should be prepared and maintained to furnish material, equipment, and services conform to the procure- evidence that the criteria enumerated above are being met ment documents. for activities required to comply with { 50.63.

4. Inspection 10. Audits A program for independent inspection of activities Audits should be conducted and documented to verify required to comply with 50.63 should be established compliance with design and procurement documents, and executed by (or for) the organization performing the instructions, procedures, drawings, and inspection and test activity to verify conformance with documented installa- activities developed to comply with Q 50.63.

O 1.155-18 mps tt, q p.e

APPENDIX B GUIDANCE REGA"dDING SYSTEIA AND STATION EQUIPMENT SPECIFICATIONS Alternate AC Sources Alternate Battery Sys* ems Safety-Related Not required, but the existing Class 1E electrical Not required, but the existing Class 1E battery Eqdpment systems must coatinue to meet all applicable systerus must continue to meet all applicable (Complience with safety-related criteria. safety-related criteria.

IEEE-279)

Redundancy 'Not required. Net required.

Diversity See Regulatory Position 3.3.5 of this guide. Not required.

from Existing i EDGs Independence Required if connected to Class IE buses. Separa- Required if connected to Class IE battery from Existing tion to be proviied by 2 circuit breakers in systems. Separation to be piovided by 2 circuit Safety-Relatad series (1 Class 1E at the Cass 1E bus and t'reakers in series (1 Class 1E at the Class 1E Systems I non-Class lE). bus and I non-Class 1 E).

Seismic Not required. Not required.

Qualification Environmental If riormal cooli-gis lost, needed for station If normal cooling is lost, necded for station Consideration blackout event only and not for design basis blackout event only and not for accident condi-accident (DEA) cor;ditior.s. Procedures should tions. Procedures should be in place to effect be in place io effect the actions necessary to the actions necessary to maintain acceptable maintain acceptable environmental conditions environmental conditions for the required for the required equipment. See Regulatory equipment. See Regulatory Position 3.2.4.

Position 3.2.4.

Capacity Specifiedin G 50.63 and Regulatory Position Specified in f 50.63 and Regulatory Position 3.3.5. 3.3.1.

Quality Indicated in Regulatory Position 3.5. Indicated in Regulatory Position 3.5.

Assurance Technical Should be consistent with the Interim Commission Should be consistent with the Interim Com-Specification 1%1 icy Statement on Technical Specifications mission Policy Statement on Technical for Maintenance, (Fcceral Register Notice 52 FR 3789) as applicable. Specifications (Federal Register Notice L.imiting Condi- 52 FR 3789) as applicable.

tion, FSAR, etc.

Instrumentation Must meet system functional requirements. Must meet system functional requirements, and Monitoring Single Failure Not required. Not required.

Common Cause Design should, to the extent practicable, Design should, to the extent practicable, Failure (CCF) minimize CCF between safety-related and non- minimize CCF between safety-related and non-safety-related systems. safety-related systems.

1.155-19

A*PENDIX B (Continued)

Water Delivery System (Alternative to Auxiliary Water Source (Existing Feedwater System, RCIC Condeniste Storage Tank Instrument Air System, or Isolation or Alternative) (Compressed Air System) Condenser Makeup)

Safety-Related Not required, but the existing Not required, but the esisting Not required, but the existing Equipment Class 1E systems must continue Class 1E systems must continue Class 1E systems must continue (Compliance with to srcet all applicable safety- to meet all applicable cafety- to meet all applicable safety-IEEE-279) related criteria. related criteria, related criteria.

Redundancy Not required. Not required. Not required.

Diversity Not required. Not required. Not required.

Independence Ensure that the existing safety Ensure that the existing safety Ensure that the existing safety from Safety- functions are not compromised, functions are not compromised, functions are not compromised, Related Systems including the capability to including the capability to including the capability to isolate comporents, subsystems, isolate components, subsystems, isolate components, subsystems, or piping,if necessary. or piping,if necessary. or piping,if necessary.

Seismic Not required. Not required. Not required.

Qualification Environmental Need for station blackout Necded for station blackout Needed for station blackout Consideration event only and not for DBA event only and not for DBA event only and not for DBA corditions. See Regulatory conditions. See Regulatory conditions. See Regulatory Position 3.2.4. Procedures Position 3.2.4. Procedures Position 3.2.4. Procedures should be in place to effect should be in place to effect should bein place to effect the actions uccessary to the actions necessary to the actions necessary to maintain acceptable maintain acceptable maintain acceptable environmental conditions environmental conditions environmental conditions for required equipment. for required equipment. for required equipment.

Capacity Capability to provice sufficient Sufficient compressed air to The capacity to provide suffi-water for core cooling in the components, as necessary, to cient cooling water Gow to event of a station blackout for ensure that the core is cooled ensure that the core is cooled the specified duration to meet and appropriate containment in the event of a station black.

G 50.63 and this regulatory integrity is maintained for the out for the specified duration guide. specified duration of station to meet { 50.63 and tids blackout to meet G $0.63 and regulatory cuide.

tids regrlatory guide.

Quality As indicated in Regulatory Asindicatedin Regulatory As indicated in Regulatory Assurance Position 3.5. Position 3.5. Position 3.5.

Technical Specifica- Should be consistent with the Should be consistent with the Should be conc.istent with the tions for Mainte. Interim Commission Policy Interim Commission Policy Interim Commission Policy nance, Suroillance, Statement on Technical Statement on Technical Statement on Technical Limiting Condition, Specifications (Federal Specifications (Federal Specifications (Federal FS AR, etc. Register Notice 52 FR 3789) Register Notice 52 FR 3789) Ref.ister Notice 52 FR 3789) as apphcable. as applicable, as applicable.

Instrumentation Must meet system functional Must meet system functional Must meet system functional and Monitoring requiremats. requiremmts. requirements.

Single Failure Not required. Not required. Not required.

- l

.g

• APPENDlX B (Continued)

,. % Water Delivery Sys**m

.i I.. \ .L (Alternative to Auxiliary

. Water Source (Existing Feedwater System, RCIC. j System,or Isolation -?

Condensate Storage Tank Instrument Air (Compressed Air System) - Condenser Makeup) .-

or Alternative) .

Common Cause Design should, to the extent Design should, to the extent Design bhould, to the extent practicable, muumize CCF practkable, mmimize CCF . practicable, minimize CCF

. Failure (CCF) between safety-related and between safety-related and between safety-related and non-safety-related systems. aan4afety-related systems. non-safety-related systemt i

j

'l '

-( k l

1.155-21

APPENDIX B (Continued)

Instrumentativa and Control Room Indications for Verifica-RCS Makeup System Isohtion Condenser tion of RCS NaturalCirculation (PWRsand BWRsWithout RCIC) (BWRs Without RCIC) (PWRsamiBWRsWithoutRCIC)

Safety Related Not required, but the existing Not required, but the existing Not required, but the existing Equipment (Com- Class 1E systems must continue Class 1E systems must continus Class 1E systems must continue pliance with to meet allapplicable safety- to meet all applicable safety- to meet all applicable safety-IEEE-279) related criteria. related criteria. related criteria.

Redundancy Not required. Not iequired. Not required.

Diverr.ity Not required. Not required. Not required.

l {

1 Independence 1. Safety-grade isolation 1. Safety-grade isolation A malfunction of this instru-from Safety- devices required between devices required between .nentation and monitoring Reiated Systems this RCS makeup system this systern snd existing system thould not affect the and existing safety-relsted safety-related systems. design safety function of any makeup water systems, safety-relhted instrumentation and mcnitoring systems

2. A malfunction of this non- 2. A malfunction of this powered by onsite or offsite safety grade makeup system non-safety-related system ac power buses.

chou 1J not affect the design should not affect the satety function of any safety- design safety function of related systems, any safety related systems.

Seismic Not required. Not required. Not required.

Qualification Environmental Needed for station blackout Needed for station bisckout Needed for station blackout Consideration event only and not for DBA event only and not for DBA event only s.nd not for DBA conditions if normal cooling is conditions if r.ormal cooling is conditions if normal cooling is lost. See Regulatory Position lost. See Regulatory Position lost. See Regulatory Position 3.2.4. Procedures should be in 3.2.4. Procedures should be in 3.2.4. Procedures should be in place to effect the actions place to effect the actions place to effect the actions necessary to maintain accept- necessary to mrintain accept- necessary to maintain accept-able environmental conditions able environmental conditians able environmental conditions for the required equipment. for the required equipment. for the required equipment.

Capacity Sufficient RCS makeup so that Provide sufficient capacity for Provide sufficient instrument.?

core temperatures are maintained decay heat removal During tian and control room indica-at acceptab;y low values con- the speci'ied duration of tions for parameters required sidering a loss of RCP water station *clackout, the isMation for verification of RCS natural byentory through a poMated condemer pool: side roouires circulation during the specified RCP seal failure & ring the a water makeup systc.u duration of station blackout.

specified duration of f.ativa powered by sourcesinde blackout, with a cinimum pendent from onsite and assumed RCP sealteaksle of offsite ac baser.

20 rpm per RCP, unless a lower v61ue is justift:1 Quality Ae indicated in Ngule*ory hs indicsted in Regulatory As indicated in Regulatory Asurano Porition 3.5. Position 3.5, Position 3.5.

O 1.155-22

,,_7 _ -

l APPENDIX B (Continued)

[

aA Instrumentation and Control Room Indications for Verifica-RCS Makeup System - Isolation Condenser tion ofRCS NaturalCirculation

. (PWRs and BWRsWithout RCIC) (BWRs Witbeut RCIC) (PWRs and BWRsWithout RCIC)~

Technical Specifica- Should be consistest with the Should be consistent with the Should be consistent with the tions for Mainte. Interim Commission Policy Interim Commission Policy ' Interin Commission Policy.

nance, Surveillance, Statement on Technient Statement on Technical Staterr.ent on Technical Limiting Condition, Specifications (Federal Specifications (Federal

• Specifications (Federal FSAR, etc. - Register Notice 52 FR 3789) Register Notice 52 FR 37E9) Register Notice 52 FR 3789) as applicable, as applicable. . as applicable. _

Instrumentation Must meet system functional Must meet system functional j and Monitoring requirements. requirements.  ;

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. Single Failure Not required. Not required. Not required. l 1

Common Cause Design should, to the extent Design should, to the extent Design should, to the extent Failure (CCF) practicable, minimize CCF practicable, minimize CCF practicable, minimize CCF .

between safety-related and between safety-related and between safety-related and non-safety-related sy8tems. non-safety-related systems. non-safety-related systems.

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REGULATORY ANALYSIS

- A separate regulatory analysis was not prepared for this e.ailable for inspection and copying for a fee at the NRC regulatory guide. The regulatory analysis prepared for the Pubic Document Room, 1717 11 Street NW., Washington, station blackout n.le, NUREG-1109, " Regulatory /Backfit DC 20555. Copies of NUREG-1109 may be purchased from Analy4s for the Resalution of Unresolved Safety issue the Superintendent of Documents, U.S. Government Printing A-44, Station Blackout," provides the regulatory basis for Office yst Office Box 37082, Washington, DC 20013-7082; this guide and examines the costs and benefits of the n.!: as or from the National Technical Information Service, l implemented by the guide. A copy cf NUREG-1109 is Springfield, VA 22161.

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eo$$' cine'tNIso UNITED STATES "**"C NUCLEAR REGULATORY COMMISSION erawir a e47 WASHINGTON, D.C. 20555 OFFICIAL BUSINESS PENALTY FOR PRIVATE USE, $300 O

1.155-24

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