ML20141C961
| ML20141C961 | |
| Person / Time | |
|---|---|
| Issue date: | 03/31/1986 |
| From: | NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | |
| References | |
| REF-GTECI-A-44, REF-GTECI-EL, RTR-REGGD-1.155, TASK-A-44, TASK-OR, TASK-RE, TASK-SI-501-4 REGGD-01.XXX, REGGD-1.XXX, REGGD-Q1.XXX, NUDOCS 8604070358 | |
| Download: ML20141C961 (16) | |
Text
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U.S. NUCLEAR REGULATORY COMMISSION March 1986 p
1, OFFICE OF NUCLEAR REGULATORY RESEARCH Division 1
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.g Task SI 501-4 DRAFT REGULATORY GUIDE AND VALUE/ IMPACT STATEMENT N*****/
)
Contact:
A.M. Rubin (301) 492-8303 a
STATION BLACK 0UT A.
INTRODUCTION j g e
Criterion 17, " Electric Power Systems," of Appendix h) h," General Design Criteria for Nuclear Power Plants," to 10 CFR Part 5074" Dom]estic Licensing of tw n%
Production and Utilization Facilities," includes e uirement that an onsite C
3 electric power system and an offsite electric powe
. stem be provided to per-ry y
mit functioning of structures, systems, and compplants important to safety.
The Commission has published proposed N to its regulations in Paragraph (a), "Requiremen{ygs,gofproposedS50.63,"Lossof 10 CFR Part 50.
All Alternating Current Power," would regt:1're&that each light-water-cot, led nuclear power plant be able to withst ecover from a station blackout Phystemconcurrentwithreactortrip (i.e., loss of the offsite electri o
7 and unavailability of the onsite emergefity AC electric power system) of a
_j specified duration.
Proposed paja k e) of General Design Criterion (GDC) 17 would require that, for thefstation blackout duration, the plant be capable b
U of maintaining core cooling andl.g ntainment integrity.
Paragraph (e) would also identify the factors that must be considered in specifying the station blackout duration.
M Criterion 18, "Jrtspection and Testing of Electric Power Systems," of Appendix A to 10 CF 50 includes a requirement for appropriate periodic
- f. ion)Hof electric power systems important to safety.
testing and insp W This guide describes a method acceptable to the NRC staff for complying N
n~
with the proposed Commission regulation that would require nuclear power plants to be capable %of*$oping with a station blackout for a specified duration.
This guide applies to all commercial light-water-cooled nuclear powcr plants.
This regulatory guide and the associated value/ impact statement are being issued in draft form to involve the pubile in the early stages of the development of a regulatory position in this area. They have not received complete staff review and do not represent an official NRC staff position.
Pubile coments are befng solicited on both drafts, the gufde (including any implementation schedule) and the value/ impact j
statement. Coments on the value/ impact statement should be accompanied by supporting data. Written coments may be i
submitted to the Rules and Procedures tranch. ORR, A0ft, U.S. Nuclear Regulatory Comission, Washington, DC 20555. Coments may also be delf vered to Room 4000 Maryland National Bank 8vilding, 7135 Old r.corgetown Road, Bethesda, Maryland from A
)
8:15 a.m. to 5:00 p.m.
Copies of coments received may be esamingune RC { gig.Dotument Room,1717 H 5treet NW.,
at th j
washington, DC.
Coments util be most helpful if received by Requests for single copies of draft guldes (which may be reproduced) or for placement on an automatic distribution Itst for single copies of future draft guides in specific divisions should be nyde in writing to the U.S. Nuclear Regulatory Comission, Washington, DC 20555. Attention: Dire: tor Olvision of Technical Information and Document Control.
8604070350 860331 PDR RECCD G1.XXXR PDR
9
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f Any information collection activities related to this draft regulatory guide are contained as requirements in the proposed revision of 10 CFR Part 50 that would provide the regulatory basis for this guide.
The proposed revision of Part 50 has been submitted to the Office of Management and Budget for clear-ance that may be appropriate under the Paperwork Reduction Act.
Such clearance, if obtained, would also apply to any information collection activities related to this guide.
B. DISCUSSION The term " station blackout" refers to the complete loss of alternating current electric power to the essential and nonessential switchgear buses in a nuclear power plant.
Station blackout therefore involves the loss of offsite power concurrent with turbine trip and failure of the onsite emergency AC power system.
Because many safety systems required for reactor core decay heat removal and containment heat removal are dependent on AC power, the consequences of station blackout could be severe.
In the event of a station blackout, the capability to cool the reactor core would be dependent on the availability of systems that do not require AC power and on the ability to restore AC power in a timely manner.
The concern about station blackout arose because of the accumulated experience regarding the reliability of AC power supplies.
Many operating plants have experienced a total loss of offsite electric power, and more occurrences are expected in the future.
In almost every one of these loss-of-offsite power events, the onsite emergency AC power supplies have been available immediately to supply the power needed by vital safety equipment.
However, in some instances, one of the redundant emergency AC power supplies has been unavailable.
In a few cases there has been a complete loss of AC power, but during these events, AC power was restored in a short time without any serious consequences.
In addition, there have been numerous instances when emergency diesel generators have failed to start and run in response to l
tests conducted at operating plants.
The results of the Reactor Safety Study (Ref.1) showed that, for one of the two plants evaluated, a station blackout event could be an important contrib-utor to the total risk from nuclear power plant accidents.
Although this total l
2
risk was found to be small, the relative importance of station blackout events was established.
This finding and the accumulated diesel generator failure experience increased the concern about station blackout.
In a Commission proceeding addressing station blackout, it was determined that the issue should be analyzed to identify preventive or mitigative measures that can or should be taken.
(See Florida Power & Light Company (St. Lucie Nuclear Power Plant, Unit No. 2) ALAB-603, 12 NRC 30 (1980); modified CLI-81-12, 13 NRC 838 (1981).)
The issue of station blackout involves the likelihood and duration of the loss of offsite power, the redundancy and reliability of onsite emergency AC power systems, and the potential for severe accident sequences after a loss of all AC power.
References 2 through 5 provide detailed analyses of these topics.
Based on risk studies performed to date, the results indicate that estimated core melt frequencies from station blackout vary considerably for different plants and could be a significant risk contributor for some plants.
In order to reduce this risk, action should be taken to resolve the safety concern stemming from station blackout.
The issue is of concern for both PWRs and BWRs.
This guide primarily addresses the following three areas:
(1) maintaining highly reliable AC electric power systems, (2) developing procedures and training to restore offsite and onsite emergency AC power should either one or both become unavailable, and (3) ensuring that plants can cope with a station black-out for some period of time based on the probability of occurrence of a station blackout at a site as well as the capability for restoring AC power in a timely fashion for that site.
One factor that affects AC power system reliability is the vulnerability to common cause failures associated with design, operational, and environmental factors. Vulnerabilities to common cause failures are plant specific; there-fore, generic guidance to improve the reliability of AC power systems by elimin-ating specific single point vulnerabilities is not practical.
Existing standards and regulatory guides include specific design criteria and guidance on the independence of preferred (offsite) power circuits (see General Design Cri-terion 17, " Electric Power Systems," and Section 5.1.3 of Reference 6) and the independence of and limiting interactions between diesel generator units at a nuclear station (see General Design Criterion 17, Regulatory Guide 1.6, "Inde-pendence Between Redundant Standby (Onsite) Power Sources and Between Their 3
l Distribution Systems," Regulatory Guide 1.75, " Physical Independence of Electric Systems," and Reference 7).
In developing the recommendations in this guide, the staff has assumed that, by adhering to such standards, licensees have mini-mized, to the extent practical, single point vulnerabilities in design and operation that could result in a loss of all offsite power or all onsite emergency AC power.
Adoption of the proposed S 50.63 and proposed paragraph (e) of GOC 17 would require all licensees and applicants to assess the capability of their plants to maintain adequate core cooling and containment integrity during a station blackout and to have procedures to cope with such an event.
This guide presents a method acceptable to the NRC staff for determining the specified duration for which a plant must be able to withstand a station blackout in accordance with the prcposed amendment to GDC 17.
The application of this method would result in selecting a minimum acceptable station blackout duration capability of either 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> or 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> depending on a comparison of the plant characteristics with those factors that have been identified as significantly affecting the risk from station blackout.
These factors include redundancy of the onsite emergency AC power system (i.e., the number of diesel generators available for decay heat removal minus the number needed for decay heat removal), the reliability of I
l onsite emergency AC power sources (e.g., diesel generators), the frequency of loss of offsite power, and the probable time to restore offsite power.
Licensees may propose durations different from those specified in this guide.
The basis for alternative durations would be predicated on plant-specific factors relating to the reliability of AC power systems such as those discussed in Reference 2.
C.
REGULATORY POSITION 1.
ONSITE EMERGENCY AC POWER SOURCES 1.1 Reliability Program The reliable operation of the onsite emergency AC power sources should be ensured by a reliability program designed to monitor and maintain the reliability of each power source over time at a specified acceptable level and to improve the reliability if that level is not achieved.
Guidance on acceptable emergency diesel generator reliability is given in Section C.1.2.
The reliability program l
4
should include surveillance testing, a reliability performance specification, and a maintenance program.
Surveillance testing should monitor performance so that if the actual performance falls below specified levels, corrective actions can be taken.
Reference 8 provides an example of a performance technical speci-fication tu support such a program.
1.2 Maximum Failure Rate The maximum emergency diesel generator failure rate should be maintained at 0.05 failure per demand for all plants.
For plants having an emergency AC power system redundancy as specified in group C of Table 2, the emergency diesel generator failure rate should be maintained at 0.025 failure per demand or less.
- 1. 3 Procedures for Restoring Emergency AC Power Guidelines and procedures for actions to restore emergency AC power when the emergency AC power system is unavailable should be integrated with plant-specific technical guidelines and emergency operating procedures developed using the emergency operating procedure upgrade program established in response to Supplement 1, " Requirements for Emergency Response Capability" (Generic Letter No. 82-33),1 to NUREG-0737, " Clarification of TMI Action Plan Requirements."
2.
OFFSITE POWER Procedures should include all actions necessary to restore of fsite power 2
and use nearby power sources when offsite power is unavailable.
As a minimum, the following potential causes for loss of offsite power should be considered:
1 Modifications or additions to generic technical guidelines that are necessary to deal with a station blackout for the specific plant design should be identified as deviations in the plant-specific technical guidelines as required by Supplement 1 to NUREG-0737 and outlined in NUREG-0899, " Guidelines for the Preparation of Emergency Operating Procedures."
2This includes such items as nearby or onsite gas turbine generators, portable generators, hydro generators, and black-start fossil power plants.
5
Grid undervoltage and collapse.
Weather-induced power loss.
Preferred power distribution system faultsa that could result in the loss of normal power to essential switchgear buses.
3.
ABILITY TO COPE WITH A STATION BLACKOUT The ability to cope with a station blackout for a certain time provides additional defense in depth should both offsite and onsite emergency AC power systems fail concurrently.
Each nuclear power plant has the capability to remove decay heat without AC power for a limited period of time.
Section C.3.1 provides guidance for determining the length of time that a plant is able to cope with a station blackout.
Section C.3.2 provides a method to determine an acceptable minumum time that a plant should be able to cope with a station blackout based on the probability of a station blackout at the site as well as the capability for restoring AC power for that site.
If the plant's station blackout capability is significantly less than the acceptable minimum duration, modifications may be necessary to extend the plant's ability to cope with a station blackout.
Should plant modifications be necessary, Section C.3.3 provides guidance on I
making such modifications.
Whether or not modifications are necessary, procedures and training for station blackout events should be provided according to the guidance in Section C.3.4.
3.1 Evaluation of Plcnt-Specific Station Blackout Capability Each nuclear power plant should be evaluated to determine its capability to withstand and recover from a station blackout.
The following considerations should be included to determine the length of time the plant is able to cope with a station blackout:
1.
The evaluation should be performed assuming that the plant is operating at full power immediately before the postulated station blackout.
l 8 Includes such failures as the distribution system hardware, switching and
{
maintenance errors, and lightning-induced faults.
l 6
s d
2.
The capability of all systems and components necessary to provide core cooling and decay heat removal following a station blackout should be identified,
)
including DC battery capacity, condensate storage tank capacity, compressed air capacity, and instrumentation and control requirements.
3.
The ability to maintain adequate reactor coolant system inventory to ensure that the core is cooled should be evaluated taking into consideration shrinkage, leakage from pump seals, and inventory loss from letdown or other norr.; ally open lines dependent on AC power for isolation.
4.
The design adequacy and capability of equipment needed to function in environmental condi.tions associated with a station blackout should be evaluated.
All AC-independent decay heat removal systems and associated equipment needed to function during a station blackout should meet design and performance standards that ensure adequate reliability and operability in extreme environments that may be associated with a station blackout, including hazards due to severe weather. Work that has already been performed need not be duplicated.
For example, if safety-related equipment needed during a total loss of AC power has been qualified to operate during environmental conditions associated with a station blackout (e.g., without heating, ventilating, and air conditioning sys-tems operating), additional analyses need not be performed.
5.
Consideration should be given to using available non-safety-related equipment, as well as safety-related equipment, to cope with a station blackout provided such equipment meets the recommendations of item 4 in Section C.3.1 of this regulatory guide.
In general, equipment required 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 site.
For equipment not located on site, consideration should be given to its availability and ac-cessibility in the time required, including consideration of weather conditions likely to prevail during a loss of offsite power.
6.
Concideration should be given to timely operator actions that would increase the length of time that the plant can cope with a station blackout.
For example, if station battery capacity is a limiting factor in coping with a station blackout, shedding nonessential loads on the DC batteries could extend the time until the battery is depleted.
If load shedding or other operator actions are considered, corresponding procedures should be incorporated in the plant-specific technical guidelines and emergency operating procedures.
D 7
)
3.2 Minimum Acceptable Station Blackout Duration Capability Each nucicar power plant should be able to withstand and recover from a station blackout lasting a specified minimum duration.
The specified duration of station blackout should be based on the following factors:
1.
The redundancy of the onsite emergency AC power system (i.e., the number of power sources available minus the number needed for decay heat removal),
2.
The reliability of each of the onsite emergency AC power sources (e.g., diesel generator),
3.
The expected frequency of Icss of offsite power, and 4.
The probable time needed to restore offsite power.
A method for determining an acceptable minimum station blackout duration capability based on these factors is given in Tables 1, 2, and 3.
Table 1 pre-sents the acceptable station blackout duration capability as a function of vari-ous specific site-and plant-related characteristics.
Tables 2 and 3 provide I
descriptions of the emergency AC power configuration groups and the offsite pow-er design characteristic groups, respectively, used in Table 1.
Table 2 identi-fies different levels of redundancy of the onsite emergency AC power system.
Table 3 provides a method for determining the offsite power design characteris-tic group as a function of the expected frequency of severe weather events, switchyard design, the number of offsite power circuits, and the ability to re-store offsite power.
After identifying the appropriate groups from Tables 2 and 3 and the reliability level of the onsite emergency AC power sources (de-termined in accordance with Section C.1.1 of this regulatory guide), Table 1 can be used to determine the acceptable minimum station blackout duration capa-bility (4 or 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />) for each plant.
3.3 Modifications to Cope with Station Blackout If the plant's station blackout capability as determined according to the guidance in Section C.3.1 of this regulatory guide is significantly less than the recommended plant-specific station blackout duration as developed according l
to Section C.3.2 of this regulatory guide (or as justified by the licensee or 8
applicant on some other basis and accepted by the staff), modifications to the plant may be necessary to extend the time the plant is able to cope with a station blackout.
If modifications are needed, the following items should be considered:
1.
If, after considering load shedding to extend the time until battery depletion, battery capacity must be extended further to meet the station blackout duration recommended in Section C.3.2 of this regulatory guide, it is considered acceptable either to add batteries or to add a charging system for the existing batteries that is independent of both the offsite and onsite emergency AC power systems such as a dedicated diesel generator.
2.
If the capacity of the condensate storage tank is not sufficient to remove decay heat for the station blackout duration recommended in Section C.3.2 of this regulatory guide, a system to resupply the tank from an alternative water source is an acceptable means to increase its capacity provided any power source necessary to provide additional water is independent of both the offsite and the onsite emergency AC power systems.
3.
If a system is required for primary coolant charging and makeup, reactor coolant pump seal cooling or injection, or decay heat removal specifically to meet the station blackout duration recommended in Section C.3.2 of this regulatory guide, the following criteria should be met:
a.
The system should be capable of being actuated and controlled from the control room; and b.
If the system must operate within 10 minutes of a loss of all AC power, it should be capable of being actuated automatically.
4.
A system or component added specifically to meet the recommendations on station blackout duration in Section C.3.2 of this regulatory guide should have limiting conditions for operation and surveillance requirements in the technical specifications consistent with those of other equipment needed to remove decay heat during a loss of all AC power.
5.
If a system or component is added specifically to meet the recommen-dations on station blackout duration in Section C.3.2 of this regulatory guide, D
9
failures of added components that may be vulnerable to internal or external hazards within the design basis (e.g., seismic events) should not result in secondary failures causing a loss of emergency AC power systems or a loss of other safety-related equiprpent.
3.4 Procedures and Training to Cope with Station Blackout Procedures 4 and training should include all operator actions necessary to cope with a station blackout for the duration determined according to Section C.3.1 or C.3.2 of,this regulatory guide, whichever is longer, and to restore normal long-term core cooling / decay heat removal once AC power is restored.
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.
This proposed guide has been released to encourage public participation in its development.
Except in those cases in which the applicant or licensee proposes an acceptable alternative method for complying with specified portions of the Commission's regulations, the method described in the final guide reflecting public comments will be used in the evaluation of submittals by applicants for construction permits and operating licenses and by licensees who are required to comply with the proposed S 50.63, " Station Blackout," and the proposed amendment to General Design Criterion 17 of Appendix A to 10 CFR Part 50.
4 Procedures should be integrated with plant-specific technical guidelines and
[
emergency operating procedures developed using the emergency operating proce-I dure upgrade program established in response to Supplement 1 of NUREG-0737.
The task analysis portion of the emergency operating procedure upgrade program should include an analysis of instrumentation adequacy during a station blackout.
10
l Table 1 Acceptable Station Blackout Duration Capability (hours)"
J D
l Emergency AC Power Configuration Group A
B C
C Maximum EDG Failure Rate Per Demand Offsite Power Design d
Characteristic Group 0.05 0.025 0.05 0.025 P1 4
4 4
4 P2 4
4 8
8 aVariations from these times will be considered by the staff if justification, including a cost-benefit a'nalysis, is provided by the licensee.
The methodol-ogy and sensitivity studies presented in NUREG-1032 (Ref. 2) are acceptable for use in this justification.
bSee Table 2 to determine emergency AC power configuration group.
CNumber of emergency diesel generator (EDG) failures in the last 100 valid demands divided by 100, dSee Table 3 to determine group P1 and P2.
D l
11 A
l Table 2 Emergency AC Power Configuration Groups Emergency AC (EAC)
NumberofEACPowgr Number of EAC Power Sources Power Configuration Sources Available Required to Operate AC-Powgred Group Decay Heat Removal Systems A
3 1
4 1
5 2
c B
2 1
4 2
l d
C 2
1 3
2 4
3 5
3 aIf any of the EAC power scurces are shared among units at a multi-unit site, this is the total number of shared and dedicated sources for those units at the site.
This number is based on all the AC loads required to remove decay heat (including AC powered decay heat retroval systems) to achieve and maintain hot shutdown at all units at the site witn offsite power unavailable, cfor EAC power sources r.ot shared with other units.
dFor shared EAC power sources in which each diesel generator is capable of pro-viding AC power to more than one unit at a site concurrently.
r I
1 12
m Table 3
)
Offsite Power Design Characteristic Groups Group Offsite Power Design Characteristics 1.
Sites that have either one of the following offsite power designs:
a.
All offsite power sources connected to the plant through two or more switchyards or separate incoming transmission lines, with at least one of the AC sources olectrically independent of the others, E
All offsite power sources connected to the plant through one switchyard or through two or more switchyards that dre electrically connected, and if the normal AC power source is lost, there is an automatic transfer to an alter-native offsite power source.
If this source fails also, there is one or more automatic or manual transfers of power to another source of offsite power, and 2.
Sites with an estimated frequency of loss of offsite power due to extremely severe weather less than 1 per 350 site years,"
and 3.
Sites that have one or both of the following characteristics:
a.
The capability and procedures for restoring offsite (non-emergency) 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 loss of offsite power due to severo weather, E
b.
An estimated frequency of loss of offsite power due to severe weather less than 1 per 100 site years.D P2 1.
Sites with an estimated frequency of loss of offsite power due to extremely severe weather greater than 1 per 100 site years.d E
2.
Sites with an estimated frequency of loss of offsite power due g
to extremely severe weather less than 1 per 100 site years" and any one or more of the following three characteristics:
13
Table 3 (Continued)
Group Offsite Power Design Characteristics P2 a.
An estimated frequency of loss of offsite power due to (Cont.).
extremnlysgvereweathergreaterthan1per350 site years E
b.
All offsite power sources connected to the plant through one switchyard or through two or more switchyards that are electrically connected and, if the normal source of AC power is lost, there are no automatic transfers and one or more manual transfers (or alternatively, there is one automatic transfer but no manual transfers) to preferred or alternative offsite power sources, E
c.
An estimated frequency of loss of offsite power due to severe b
weather greater than 1 per 100 site years without the cap-ability and procedures for restoring offsite (nonemergency)
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 loss of off-q site power due to severe weather, aThe estimated frequency of loss of offsite power due to extremely severe weather is determined by the annual expectation of storms at the site with wind velocities equal to or greater than 125 mph.
bThe estimated frequency of loss of offsite power due to severe weather, f, is determined by the following equation:
f = (1.8 x 10~4)hy + (27)h2 + (2.6 x 10-2)h3 where h3 = annual expectation of snowfall for the site, in inches, 2== annual expectation of tornadoes per square mile at the site, and h
annual expectation of storms at the site with wind velocities h3 between 75 and 124 mph.
The annual expectation of snowfall, tornadoes, and storms is obtained from National Weather Service data from the weather station nearest to the plant or by interpolation, if appropriate, between nearby weather stations.
The basis for the empirical equation for the frequency of loss of offsite power due to severe weather, f, is given in Reference 2, Appendix A.
I 14
REFERENCE 3
.-n/
1.
U.S. Nuclear Regulatory Comission, " Reactor Safety Gtudy," WASH-1400, October 1975.
2.
U.S. Nuclear Regulatory Conmission, " Evaluation of Station Blackout Acci-dents at Nuclear Power Plants. Technical Findings Related to Unresolved Safety Issue A-44," NUREG-1032, Draft, May 1985.
3.
U.S. Nucitar Regulatory Commission, " Collection and Evaluation of Complete and Partial Losses of Offsite Power et Nuclear Power Plants, NUREG/CR-3992, February 1985.
4.
U.S. Nuclear Regulatory Commiscion, " Reliability of Emergency AC Power Sources at Nuclear Power Plants," NUREG/CR-2989, July 1983.
5.
U.S. Nuclear Regulatory Commission, " Station Bleckout Accident Analyses (Part of NRC Task Action Plan A-44)," NUREG/CR-3226, May 1983.
6.
Institute of Electrical and Electronics Engineers, "IEEE Standard for Preferred Pcwor Supply for Nuclear Power Generating Stations," IEEE Std 765-1983.*
7.
Institute of Electrical and Electronics Engineers, "IEEE Standard Criteria for Diesel-Generator Units Applied as Standby Power Supplies for Nucicar Power Generating Stations," IEEE Std 387-1984.*
8.
U.S. Nuclear Regulatory Commission, " Proposed Staff Actions to Improve and AA Maintain Diesel Generator Reliability," Generic Letter 84-15, July 2, 1984
- Copies may be obtained from the Institute of E1cetrical and Electronics Engineers, 345 E. 47th Street, New York, NY 10017.
- Copies may be examined or copied for a fee at the NRC Public Document Room, l
1717 H Street NW., Washington, DC.
15
4 VALUE/ IMPACT STATEMENT A separate value/ impact statement was not prepared for this draft regu-latory guide.
The regulatory analysis (NUREG-1109) prepared for the proposed rule that would provide the regulatory basis for this guide examines the costs and benefits of the rule as implemented by the guide.
A copy of NUREG-1109 is available for inspection and copying for a fee at the NRC Public Document Room, 1717 H Street NW., Washington, DC 20555.
Free single copies may be obtained upon written request to the Division of Technical Information and Document Control, U.S. Nuclear Regulatory Commission, Washington, DC 20555.
l UNITED STATES nRsr etass unit NUCl.E AS REGULA1 CRY COMMISSION Posta's*d'""'
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Pf RMif No. 0 47 0FFICIAL BUS' NESS PEN ALTY FOR PNVATE Vst, $3nr) l 120555064215 1 IS11SA10P11S US ARC t DM-DI V OF TICC DGOUPENT CONTROL DESK-R ECSE 042 WASHINGTON OC 20555 1
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