ML20072P758

Station Blackout Evaluation,Beaver Valley Power Station, Units 1 & 2 Final Technical Evaluation Rept

ML20072P758
Person / Time
Site:	Beaver Valley
Issue date:	08/27/1990
From:	SCIENCE APPLICATIONS INTERNATIONAL CORP. (FORMERLY
To:	NRC
Shared Package
ML20072P759	List: ML20072P758
References
CON-NRC-03-87-029, CON-NRC-3-87-29 SAIC-89-1159, TAC-68510, TAC-68511, NUDOCS 9009060130
Download: ML20072P758 (31)

Text

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ATTACHMINT 1 SAIC 49/1159 l

j TECMICAL DALUATION REPORT l BEAVER VALLEY POWER STATION UNIT 1 A2 UNIT 2 STATION BLACK 0UT DALUATION 1

TAC Nos. 64510 and 68511 SAIG~

Science Applications Internellonel Corporation An Emp%yee Owned Company i

Final August 27, 1990 I

l Prepared for:

U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Contract NRC 03 87 029 Task Order No. 38 ,

Post CMce Box 1303,1710 GoceQpe Drive, McLean, Virgirus 22102 (703) 8214300 D O 3(O

i TABLE OF CONTENTS section I h

1.0 BACKGROUND

............................................ I  !

2.0 l REVIEW PROCESS ....................................... 2 l

3.0 EVALVATION .......................................... 6 j

3.1 Proposed Station Blackout Duration .............. 6 3.2 Alternate AC (AAC) Power Source ................. 9 3.3 Station Blackout Coping Capability .............. 15 3.4 Proposed Procedures and Training ................ 22 i

3.5 Proposed Modifications .......................... 23  ;

3.6 Quality Assurance and Technical Specifications .. 24

4.0 CONCLUSION

S .......................................... 25

5.0 REFERENCES

.......................................... 27

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TECHNICAL EVALUATION REPORT BEAVER VALLEY POWER STATION UNIT 1 AND UNIT 2 STATION BLACK 0UT EVALUATION

1.0 BACKGROUND

On July 21, 1988, theNuclearRegulatoryCommission(NRC)amendedits regulations in 10 CFR Part 50 by adding a new section, 50.63, " Loss of All Alternating Current Power" (1). The objective of this requirement is to assure that all nuclear power plants are capable of withstanding a station blackout (SBO) and maintaining adequate reactor core cooling and appropriate containment integrity for a required duration. This requirement b based on information developed under the commission study of Unresolved Sainy Issue A-44,"StationBlackout"(2-6).

The staff issued Regulatory Guide (RG) 1.155, " Station Blackout," to provide guidance for meeting the requirements of 10 CFR 50.63 (7). Concurrent with the development of this regulatory guide, the Nuclear Utility Management and Resource Council (NUMARC) developed a document entitled, " Guidelines and Technical Basis for NUMARC Initiatives Addressing Station Blackout-at Light Watar Reactors," NUMARC 87-00 (8). This document provides detailed guidelines and procedures on how to assess each plant's capabilities to comply with the SB0 rule.

The NRC staff reviewed the guidelines and analysis methodology in NUnARC 87-00 Md concluded that the NUMARC document provides an acceptable guidance for wuressing the 10 CFR 50.63 requirements. The application of this method results in selecting a minimum acceptable SB0 duration capability from two to sixteen hours depending on the plant's characteristics and vulnerabilities ta the risk from station blackout. The plant's characteristics affecting the required coping capability are: the redundancy of the onsite emergency AC power sources, the reliability of onsite emergency power sources, the frequency of loss of offsite power (LOOP), and the probable t 'me to restore c.ffsite power.

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In order to achieve a consistent systematic response from licensees to the SB0 rule and to expedit. the staff review process, NUMARC developed two 1

generic response documents. These documents were reviewed and endorsed by the NRC staff (14) for the purposes of plant specific submittals. The documents are titled:

1. " Generic Response to Station Blackout Rule for Plants Using i Alternate AC Power," and

2. " Generic Response to Station Blackout Rule for Plants Using AC Independent Station Blackout Response Power."

1 A plant-specific submittal, using one of the above generic formats, l provides.only a summary of results of the analysis of the plant's station blackout coping capability. Licensees are expected to ensure that the baseline assumptions ut# in NUMARC 87-00 are. applicable to their plants and )

to verify the accuracy of the stated results. . Compliance with the S80 rule requirements is verified by review and evaluation of the licensee's submittal and audit review of the supporting documents as necessary. Follow up NRC inspections assare that the licensee has implemented the necessary changes as required to meet the SB0 rule.

In 1989, a joint NRC/SAIC team healed by an NRC staff member performed audit reviews of the methodology and Scumentation that support the licensees' submittals for several plants. These audits revealed several deficiencies -

which were not apparent from the review of the licensees' submittals using the agreed upon generic response format. These deficiencies raised a generic questf e.n regarding the degree of the licensees' conformance to the requirements of the SB0 rule. To resolve this question, on January 4, 1990, NUMARC issued additional guidance as NUMARC 87-00 Supplemental Questions / Answers (15) addressing the NRC's concerns regarding the deficiencies. NUMARC requested that the licensees send their supplemental responses to the NRC addressing these concerns by March 30, 1990. '

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. l 2.0 REVIDi PROCESS '

The review of the licensee's submittal is focused on the following areas consistent with the positions of RG 1.155; A. Minimum acceptable SB0 duration (Section 3.1),

B. SB0 coping capability (Section 3.2),

C. Procedures and training for SB0 (Section 3.4),

D. Proposed modifications (Section 3.3), and E. Quality assurance and technical specifications for SB0 equipment (Section3.5).

For the determination of the proposed minimum acceptable SB0 duration, the following factors in the licensee's submittal are reviewed: a) offsite power design characteristics, b) emergency ac power system configuration, c) determination of the emergency diesel generator (EDG) reliability consistent withNSAC-108 criteria (9),andd)determinationoftheacceptedEDGtarget l reliability. Once these factors are known, Table 3-8 of NUMARC 87 00 or Table 2 of Regulatory Guide 1.155 provides a matrix for determining the required coping duration. '

For the SB0 coping capability, the licensee's submittal is reviewed to assess the availability, adequacy and capability of the plant systems and comnonents needed to achieve and maintain a safe shutdown condition and recover from an SB0 of acceptable duration which is determined above. The review process follows the guidelines given in RG 1.155, Section 3.2, to assure:

a. availability of sufficient condensate inventory for decay heat removal, 3

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4 b, adequacy of the class lE battery capacity to support safe shutdown,

c. Availability of adequate comp'essed air for air operated valves

- necessary for safe shutdown,

d. adequacy of the ventilation systems it, the vital and/or dominant areas that include equipment necessary for safe shutdown of the plant, l

e. ability to provide appropriate containment integrity, and

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f. ability of the plant to maintain adequate reactor coolant system inventory to ensure core cooling for the required coping duration.

The licensee's submittal is reviewed to verify that required procedures (i.e., revised existing and new) for coping with SB0 are identified and that appropriate operator training will be provided.

The licensee's submittal for any proposed modifications to emergenc;< AC sources, battery capacity, condensate capacity, compressed air capacity, appropriate containment integrity and primary coolant make-up capability is reviewed. Technical specifications and quality assurance set forth by the licensee to ensure high reliability of the equipment, specifically added or arsigned to meet the requirements of the SB0 rule, are assessed for their adequacy.

l The licensee's proposed use of an alternate AC power source is reviewed to determine whether it meets the criteria and guidelines of Section 3.3.5 of RG 1.155 and Appendix B of NUMARC 87-00.

This SB0 evaluation-is based on a review of the licensee's submittals dated April 14, 1989 (10), March 30, 1990 (13), June 29, 1990-(19), and July 27, 1990 (20), the information available in the plant Updated Final Safety Analysis Reports (UFSAR) (11 and 12), a telephone conversation between 4

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' l NRC/SAIC and the licensee on February 5, 1990 and a follow up meeting between l the licensee and its consultant an'd the NRC/SAIC rev'iew team at the NRC l Headquarters on February 22, 1990 (16), and a telephone conversation between the NRC/SAIC and the licensee on July 20, 1990; it doet not include a concurrent site audit review of the supporting documentation. Such an audit may be warranted as an additional confirmatory action. This determination would be made and the audit would be scheduled and performed by the NRC staff at some later date, t

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I 3.0 EVALUATION 3.1 Proposed Station Blackout Duration l

l Licensee's Submittal The licensee, Duquesne Light Company (DLC), calculated (10 and 13) a-minimum acceptable station blackout duration of four hours for the Beaver Valley Pc er Station (BVPS) Unit I and Unit 2. The licensee stated that no mod;fications &r:: n:: ssary to attain this proposed coping duration.

The plant factors used to estimate the proposed SB0 duration are:

1. Offsite Power Design Characteristics The plant AC power design characteristic group is "P2" based on:

a. Independence of the plant offsite power system characteristics of "I3,"

b. Estimated frequency of LOOPS due to extremely severe weather (ESW) which places the plant in ESW group "1,"

c. Expected frequency of grid-related LOOPS of less than one per 20 years, and d.

Estimated frequency of LOOPS due to severe weather (SW) which places the plant in SW group "2."

2. Emergency AC (EAC) Power configuration Group-The EAC power configuration of each unit is "C." Each unit at BVPS is equipped with two emergency diesel generators which are normally available to the unit safe shutdown equipment.

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One EAC power supply per unit is necessary to operate safe shutdown equipment following a loss of offsite power.

3.

Target Emergency Diesel Generator (EDG) Reliability The licensee has selected a target EDG rollability of 0.975. The selection of this target reliability for BVPS Unit 1 is based on having an average EDG reliability of greater than 0.95 for the last 100 demands consistent with the NUMARC 87 00 selection criteria. The licensee stated that the actual reliability values for the last 100 valid start demands at BVPS Unit I to be 0.99 and 1.00 for the EDG Nos.1 and 2, respectively. BVPS Unit 2, which was licensed in 1987, had only 19 valid start demands on EDG No I ano 17 valid start demands on EDG No. 2 with no failure recorded at the time the submittal was being prepared.

Review of Licensee's Submittal Factors which affect the estimation of the SB0 coping duration are: the independence of the offsite power sy:; tem grouping, the estimated frequency of LOOPS due to ESW and SW conditions, the expected frequency of grid-related LOOPS, the classification of. EAC, and the selection of EDG target reliability. The licensee's estimation of the frequency of LOOPS due to ESW condition conforms with that given in Table 3-2 of NUMARC 87-00.

Using Table 3-3 of NUMARC 87-00, the expected frequency of LOOPS at BVPS due to SW condition is estimated to be "0.0109" or "0.0067" placing the-site in an SW group "3" or "2" depending on the site having offsite power transmission lines either on one or multiple rights-of-way, respectively. The licensee's submittal stated that the plant-is in SW group "2" indicating that the site has power transmission lines on multiple rights-of-way. A review of the Unit I and 2 UFSARs indicates that the site could be considered to have transmission lines on multiple rights-of-way.

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. . 1 Our review of the BVPS Unit I and 2 UFSARs'indic'ates that the licensee I has properly evaluated the plant independence.of the offsite power  !

grouping, and the EAC classification as "!3" and. "C," respectively. J L

The licensee s'tated that the selection of EDG target reliability of 0.975 is based on the demonstrated EDG start-up and load run reliability. However, we are unable _to perform a detailed review of the l plant EDG reliability since the information is only available onsite.

The available information in the NSAC-108,-which gives the EDG reliability data at U. S. nuclear reactors _ for calendar yearr 1983 to 1985, indicates that the EDGs at- BVPS Unit 1 experienced an average of 24 valid start demands per calendar year with an. ave'r age unit reliability of 0.965 per diesel per year. Using this data, it appears .

-that the target EDG reliability (0.975) selected by the licensee (10) to be appropriate.- In response to the requirement for an EDG' reliability program, the licensee stated during a telephone conversation on February 5, 1990, that'a reliability program consistent with the guidance provided in RG 1.155 and NUMARC 87-00 will be developed. This is documented in the licensee's submittal dated March 30,1990(13). In addition the licensee stated that.the targete'd EDG reliability will be maintained. However, an audit may be required to ensure compliance.

With regard to the expected frequency of grid-related LOOPS at the site,

.we can not confirm the stated results. .The available information in ~

NUREG/CR-3992(3),whichgivesacompendiumofinformationontheloss of offsite power at nuclee peer plants in U.S., indicates that BVPS did not have a grid-related LOOP up to 1984. During the telephone conversation on February 5,1990, the licensee stated that he is not

' aware of any grid-related LOOPS at the site. In the absence of any contradicting information, we agree with the licensee's statement.

Based on the above, the AC power design characteristics of the BVPS site is "P2" with a minimum required SB0 coping duration of four hours.

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1 3.2 AlternateAC(AAC)powerSource Liccnsee's submittal The licensee stated that the AAC power source at BVPS will be an emergency AC power source from the non blacked out unit which meets the criteria specified in Appendix B to NUMARC 87-00 and the assumptions in <

Section 2.3.1 of NUMARC 87-00. The proposed AAC configuration at BVPS is shown in Figure 1 (13). The licensee stated that, with this configuration, any one of the blacked out unit emergency buses can be energized manually from either of the emergency buses of the opposite.

unit. The- AAC power source will be available within-one hour of the onset of an SB0 event and hr.s. sufficient capacity and capability to operate. equipment and systems necessary for coping with an SB0 for the required SB0 duration of four hours. All breaker operations will be performed locally.

Review of Licensee's submittal i ,

The licensee's proposed AAC power source configuration, see Figure 1, j conforms to a variation of an acceptable configuration provided in NUMARC 87-00 Supplemental Questions / Answers under Question C.1 (15).

The AAC power source, one of the site EDGs, meets all the required criteria in Appendix B of NUMARC 87-00 except for the following cases:

o Paragraph B.9 of Appendix 8 states, "the AAC power source shall be

... capable of maintaining voltage and frequency within limits l consistent with established industry standard that will not degrade the performance of any shutdown system or component. At a multi-unit site, except for 1/2 Shared or 2/3 emergency AC power configuration, an adjacent unit's Class IE power source may be used as an AAC power source for the blacked-out unit if it is capable of powering the required loads at both units."

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i L o Paragraph B.12 of appendix B states, " ... the AAC system shall be demonstrated by the initial test to be capable of powering I required shutdown equipment within one hour of station blackout event."

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! The guidance on the use of existing EDGs as AAC power sources at multi-unit sites is documented in RG 1.155,-Section 3.3.5, NUMARC 87-00, l l

Section 2.3.l(3) and under question 3.4 and B.3 in NUMARC 87 00 Supplemental Questions / Answers, and further detailed in_ References 17 and 18. In addition,_the SB0 rule states that at multi unit sites where the combination of EAC power sources ' exceeds the minimum redundancy.

requirements for safe shutdown (non-DBA) of all units, the remaining EAC sources may be used as AAC sources' provided that they mest the 'i applicable requirements.

The rule statement requires ' minimum redundancy.' This means that in 1 order for an EDG to-qualify as an AAC source there must be an EDG available in the NB0 unit in. addition to the number of EDGs required to  ;

meet the minimum EDG redundancy requirement for powering a normal safe shutdown loads following a LOOP event. Thus, the EDGs in a two-unit site with two dedicated EDGs per unit would'not qualify as AAC sources.

Two EDGs per unit would meet only the minimum redundancy requirement, and there is no excess EDG.  !

l However, there are some plants it multi-unit sites which have EDGs' that l just meet the minimum redundancy but each EDG-has ~ sufficient capacity to power all the normal LOOP loads of the NB0 unit and also has sufficient excess capacity to power the required safe shutdown loads of the SB0 l l unit. Recognizing the existence of this type of situation, the staff has interpretsd the 'litera?' excess EDG redundancy requirement of the SB0 rule to allow large capacity EDGs to qualify as AAC sources, provided other applicable requirements are met.

In order to take credit for this interpretation, the NRC staff's basic position has been (17 and 18) that:

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. _ - - _ _ - _ _ _ _ - _ - _ ~ - _ _ _ _ _ _ - _ _ __ _ _ _ __ _ --- _ - .

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no action should be taken that would exacerbate the already.

difficult situation in the N80 unit. Any actions'that make operator tasks more difficult such as load switching or disablement of information readouts or alarms in the control room i are also considered to be a degradation of normal safe shutdown capability for 1.00P in the NB0 unit. And, i 1

2. excess capacity of the EDG being designated as an AAC source should not be the capacity made available by shedding or not powering normal safe shutdown loads in the NBO' unit. Examples of such loads are: . motor driven auxiliary feedwater pumps; heating, ventilation and air conditioning loads; the power supply of the plant computer; one or more sets of redundant instrumentation; etc. The shedding of such loads constitutes degradation of the I normal safe shutdown capability of the NB0 unit.

It is not in the interest of safety to reduce the capability to handle variou eventualities in one unit for the purpose of meeting the SB0 rule in another unit. Each unit must meet the SB0 rule on its own merits without reducing another unit's capability to respond to its own potential problems.

The excess capacity of the EDG in the N80 Onit that qualifies it as an AAC source is, therefore, 'only that available capacity within the i

normal continuous rating but above the EDG load represented by the complete contingent of safety related and non-safety related loads normally expected to be available for the LOOP condition.'

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l During the telephone conversation on February 5,1990, the licensee stated that load shedding is required for a condition where Unit 1 is L the non-blacked out (NBO) unit. During an S80 event, a load management scheme is needed to ensure that selected SB0 equipment in Unit 2 could-be powered from one of the EDGs in Unit 1. The licensee presented this load management scheme to the NRC staff during a public meeting at the 12 l

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NRC Headquarters in Rockville, Maryland on February 22, 1990. The staff j

concluded (16) that the licensee's load managemenc scheme did not conform to the above guidance.

On June 29, 1990 (19), the licensee submitted a revised SB0 AAC load

. management scheme for the BVPS units-and provited reasoning on why'the proposed scheme should be. acceptable.. The licensee stated that'each EDG at Unit 1 needs to carry a total of 2,889 kW. This load exceeds both the continuous and the 2,000 hour0 days <br />0 hours <br />0 weeks <br />0 months <br />. rating of each EDG at Unit 1, whic;r are 2,600 and 2,850 kW, respectively. Therefore, the present.h ad management does not' conform to the staff's position that eitner a  :

continuous or a 2,000 hour0 days <br />0 hours <br />0 weeks <br />0 months <br /> rating of the EDGs be.used.

The revised submittal (19) identified the following SB0 loat's for iach unit:

Eauioment Unit 1 Unit 2 Battery Charger 38 .14.6 Control Room Fans 73. 27.4 Control Rod Cooling Fans 81 56

Battery Room Exhaust Fan 6.2 -6.2 Emergency Switchgear Fans 21 --

I Miscellaneous Trans. Losses  ?

85.6 , .

River Water Pump 338 --

Control Room Air Condition 61 --

Subtotal $80 Loads (102 189.8 NOTE: No values were given for transformer losses in Unit 1.

In addition to trese SB0 loads, the licensee considered one charging pump in each un't as a discretionary load that can be used. Yet, the licensee's coping evaluation did not take credit for the use of the charging pump as a mean to maintain reactor coolant inventory. The LOOP loads identified in the NB0 unit (Unit 1) did not include the turbine-13

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bearing lube oil pump, bearing oil lift pump, and gear drive, residual heat removal (RHR) pump, containment air recirculation (CAR) fans, containment .ir compressor (CAC), and fuel pool cooling pump.

The licensee's justifications for not considering the~RHR and the turbine loads' are that the RHR pump is notlneeded for the-first four.

hours, and the turbine loads are either not needed after one hour or not required for safe shutdown. We disagree with the licensee's position, and believe that the proposed load management scheme is'not consistent with the guidance provided above.- I 4

With regard to the CAR fans and CAC, the licensee stated that the cooling system (chilled water system) for these components is not safety related and, therefore, it is not-supported by-the EDGs..'The continued i operation of the CAR fans would have a reverse impact, 1.e. it adds additional heat to the containment. The containment air compressor would only operate for a short period without cooling. Therefore they need to be turned off. In addition the licensee stated that an actual-operating experience has shown that the containment air temperature would not exceed above Il0*F during the first four hours without

-containment cooling. This event is recorded in a licensee event report, LER 84-07. Although we did not review the stated event, we agree with the licensee that if no cooling-is available Lto the CAR fans and CAC they should be turned off.

We also believe that the licensee needs to revise Table 8.5-1 of the Unit 1 UFSAR to indicate that the CAR fans and CAC will not be. loaded, or willo'e turned off, since no cooling is l available to support their operations.

L On July 20, 1990, during a telephone conversation the licensee was i

informed by the NRC staff to revise the LOOP load list on Unit 1 EDG by L including-the RHR and the turbine auxiliary loads to the NB0 loads (Unit

1) and deleting the charging pump (discretionary) load from the SB0 loads (Unit 2). With this change, when. Unit 1 is an NB0 unit, the total EDG load will be less than its 2,000 hour0 days <br />0 hours <br />0 weeks <br />0 months <br /> rating. The licensee agreed with the staff position and provided the revised load list on July 27, i 14 l

1990 (20). Based on this commitment, each of the Unit 1.EDGs will have sufficient excess capacity to power a selected $80 equipment at Unit 2, i and the proposed AAC power source will conform to the guidance.

I The licensee needs only to demonstrate by a test that the AAC power i source can supply the shutdown buses within one hour from the onset of an SBO.

3.3 Station Blackout Coping Capability The plant coping capability with a station blackout for the required duration of four hours is assessed based on the following results:

1. Condensate Inventory for Decay Heat Removal Licensee's Submittal

.The licensee's submittal dated April 14, 1990 (10) stated that a, total of 110,886 gallons of condensate water are required for each

, unit for a 4-hour decay heat removal and' plant cooldown . In its revised submittal dated March 30, 1990 (13), the-licensee stated that.87,604 gallons would be needed for decay heat removal and cooldown to an average reactor coolant. system (RCS) . temperature of 350'F . The minimum permissible condensate storage' tank (CST) level per technical specification provides 140,000 gallons of water for Unit I and 127,000 gallons for Unit 2, both of which

. exceeds the required quantity for coping wit a 4-hour station blackout. The licensee added that no plant modifications or procedure changes are needed to.use these water sources.

Review of Licensee's submittal For the evaluation of the condensate requirement for decay heat removal (OHR) and the RCS cooldown to 350'F, we used the information avai'able in the plants UFSARs, and the guidance 15 l

.I provided in NUMARC 87 00. Using the expression provided in NUMARC 87-00, we estimated that each unit would need 58,663 gallons of condensate'for decay heat removal during a 4-hour S80 event. This is based on the licensed thermal power of 2,652 MWt, corresponding L to 100% power.

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For the cooldown calculation, we used the total RCS stored energy l of 599.87x '10' Btu given in ' Table 6.2-8 of the Unit 2 UFSAR.

Based on this information and.an average RCS temperature of 575'F (average RCS temperature in the~ reactor vessel), we have estimated that -25,150 gallons of condensate water would be needed, in addition, condensate water would be needed to supplement the level shrink in the steam generators during the RCS cooldown. Our calculations indicate that -109,600 gallons of condensate would be needed_ for decay heat removal and cooldown. Therefore, the licensee's original evaluation of 110,886 gallons (10) is a correct representative of the needed condensate for the proposed cooldown.

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Based on above, we. agree with the licensee that each unit;has-l sufficient condensate inventory to cope with a 4-hour SB0 event.

2. Class lE Battery capacity i

Licensee's Submittal The licensee stated that the class lE batteries at both units have l been reviewed ad determined that they have sufficient capacity to power the needed SB0 equipment for.one hour without charge.

Review of Licensee's Submittal l

According to the BVPS Unit I and Unit 2 UFSARs the class lE batteries are sized to provide power to the essential DC loads for two hours without being charged. However, after one hour when the 16 l

AAC power source is established the battery charger (s) for one division will be connected to the AAC source. Therefore, we agree with the licensee that the BVPS units have sufficient battery capacity to support the SB0 loads. '

3. Compressed Air i

Licensee's submittal l

The licensee stated that the air operated valves relied upon t'o  :

cope with a station blackout for one hour can be operated manually. Valves requiring manual operation during an SB0 event  ;

are identified in plant procedures. '

Review of Licensee's submittal The licensee stated that the instrument air system would not be available during an SB0 event.

The licensee also stated that the reactors will be cooled down. The RCS cooldown in the PWRs are achieved by lowering the steam generator pressure. This is accomplished by using the AFW pump, here the turbine driven pump, to inject the demineralized condensate water into the steam

' generators and using atmospheric dump valves to release the deca.y l

heat while gradually lowering the steam generator pressure.

Review of the Unit 1 UFSAR indicates its ADVs are air operated valves, therefore, requiring manual action for its operation v .ng an SB0 event. The AFW flow control valves are AC-powered motor-operated valves and each is equipped with handwheel that can be used to adjust flow manually upon loss of power.

Review of the Unit 2 UFSAR indicates that the ADVs and the AFW flow control valves are electro-hydraulic-operated valves. The UFSAR states that these valves are powered from emergency buses.

The ADVs for this unit is also powered from the emergency buses.

l In the absence of AC power during the an S80 event these valves 17

l need to be operated locally and manually to adjust the AFW flow l l and to control the steam generator pressure.

Our review indicates that the heat removal system at both units require local manual actio*.s. A successful decay heat removal operation requires coordination of at least three operators: one in the control room, second one at the ADVs, and the third at the AFW flow control valves. Therefore, the licensee needs to simulate this operational scenario and train the operators accordingly.

4. Effects of Loss of Ventilation Licensee's Submittal The calculated post-SB0 steady state ambient air temperature for areas containing SB0 equipment are as follows:

Area Temperature (*F) f_inal Initial Unit 1 AFW Pump Room 118- 104 Unit 2 AFW Pump Room 114 104 Unit 2 Process Instrument Room 115 'NA Unit 1/2 Control Room 114/115 88 Main Steam Valve Room 121.5 NA NA = Not Available The licensee stated that except for the joint control room, the heating, ventilation and air conditioning (HVAC) systems serving the above areas would not be available during an SB0 event.

During an SB0 event, the control room complex air conditioning l

units would not be available. However, the control room supply  ;

and exhaust fans would be available when the AAC power source is 18

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established. The licensee stated that since AAC would not be available for the first hour after an SB0 event, both control rooms were evaluated for a complete loss of ventilation during an SB0 event.

l The licensee stated that the unit 1/2 river water pump cubicles, I which were considered to be a dominant area of concern (DAC) in the submittal dated April 17, 1989, were excluded from the OAC list. The licensee reasoned that, since these pump cubicles are common for both units, sach having a separate ventilation system, the loss of one system 'or the, blacked out unit does not jeopardize the unaffecttd unit's ventilation or equipment required for safe shutdown.

The licensee stated that the SB0 equipment operability in the dominant areas of concern (Unit 1 main steam valve room) has been assessed using Appendix F to NUMARC 87-00 and/or the Topical Report. The licensee concluded that no modifications are required to provide reasonable assurance for equipment operability. The licensee added that procedure changes,. associated with the opening ventilation louvers, will be implemented to cope with the SB0 event.

Review of Licensee'S Submittal:

l l The licensee provided the heat-up calculations for the Unit 1 and-2 control rooms and auxiliary feedwater rooms. These analysis used the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> NUMARC methodology for steady-state temperature rise calculations. The calculations are based on given loads with specified references which are not available for our . review.

Assuming the loads are correct, the calculation appears to be reasonable. However, the licensee needs to provide a procedure for opening the cabinet doors in the control rooms within 30 minutes from the onset of an SB0 event consistent with the guidance provided in NDMARC 87-00 Supplemental Qtestions/ Answers.

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I The licensee stated that the-calculated temperature of the Unit 1 main steam valve room (MSVR) is based on a credit from opening the  :

L ventilation louvers located in the MSVR ceiling. The information provided by the licensee and those available in .the plant UF',ARs are inadequate to confirm the stated results. Therefore, .n~ audit I may be required to confirm compliance.

5. Containment Isolation Licensee's Submittal The licensee reviewed the plant list of containment isolation valves -(CIVs) to verify .that valves which must be capable of being einsed or operated (cycled). under station blackout conditions can be pcsitioned (with indication) independent of the preferred and blacked out unit's class IE power supplies. The licensee stated that no plant modifications are necessary to ensure that appropriate containment integrity is provided under SB0 conditions.-

Review of Licensee's Submittal We' performed an independent review of the plant CIVs given in l

Table 5.3-1 of Unit 1 UFSAR and Tabl'e 6.2-60 of Unit 2 UFSAR to identify those CIVs requiring manual or power operated. closure capability. After axcluding those CIVs that conform to the-criteria stated in the RG 1.155, Section 3.2.7, we found the following valves require closure capability to ensure appropriate

j. containment integrity:

l Valves Status / Fail ((Ig yg[t RSS MOV 155A&8 OPEN/AS IS 12"

' 1/2 RSS-MOV 155C&D {

0/EN/AS IS 12" 2 l CHS-MOV 381- OPEN/AS IS 3" 1/2 IAC-MOV 134 OPEN/AS IS 4" 2 20 l

l The licensee needs to address the closure of these valves in appropriate procedures..

l 6. Reactor Coolant Inventory l

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Licensee's Submittal l

The licensee's submittal. dated April 14, 1989 (10) stated that the  !

AAC source powers the necessary makeup systems to maintain adequate reactor coolant system invent?ry to ensure that the core is cooled for the required coping durat'on.- In its revised submittal dated March 30,1990(13), the licensee stated that the

- generic analyses listed in Section 2.5.2 of NUMARC 87-00, which are applicable to the specific design of BVPS Unit I and 2, were used to: assess the plant's ability to maintain adequate reactor coolant system inventory. The. licensee added that the expected rates of reactor coolant inventory losses under SB0 conditions do not result in core uncovering during the required coping duration of four hours.

Review of Licensee's Submittal The reactor coolant system (RCS) inventory losses which the licensee needs to consider are:

1, 25 gpm per pump losses through reactor coolant pump seals per NUMARC guidelines,

2. maximum allowable RCS leakage per plant technical specifications (a 25 gpm is assumed).

In addition, the licensee needs to consider additional losses in terms of the RCS volume shrink due to the proposed RCS cooldown to an average temperature of 350'F.

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t The revised licensee's submittal (13) uses the generic analyses '

referenced in NUMARC 87 00 to indicate that the core will not be uncovered during a 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> $80 event. However, the licensee neither identifies the exact reference nor states whether the l assumptions in the referenced analysis bounds the conditions of j

the'BVPS reactors during an S80 event. . We assumed that an appropriate analysis consistent with the above leakage rate is available as part of. documentation supporting the-plant's SB0 submittal.

Our analysis of the RCS inventory losses, i.e. shrinks and leaks, indicates that each reactor, on the average, loses an equivalent of ~170 gpm during the 4 hour4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> $B0. . This RCS inventory. loss does not result in core uncovering during a 4-hour SBO,"and the reactor cooldown will be sustained by natural circulation and reflux condensation in the steam generator U tubes.

3.4 Proposed Procedures-and Training Licensee's Submittal The licensee stated that the following plant procedures have'been reviewed per guidelines in NUMARC 87-00, Section 4: -

l 1. AC power restoration, i 2. Severe weather, and

3. Station blackout response guidelines.

The licensee listed the name(s) of the plant procedures which fall in each of above categories in the plant S80 submittal. The procedures for severe weather and AC power restoration did not require any modifications. The licensee stated that required changes to the station emergency operating procedures have been identified and will be implemented within one year. The procedures associated with establishing the AAC power source will be completed within 2 years after 22

0 NRC acceptance and following implementation of the proposed modification of the plant for MC power source.

Review of Licensee's Submittal We neither received nor reviewed the affected SB0 procedures. We consider these procedures as plant specific actions concerning the required activities to cope with a. 7s0. We believe that it is licensee's responsibility to revise and implement these procedures, as needed, to mitigate an SBO. event and to assure that these procedures are complete and correct, and that the associated training needs are carried out accordingly. I 3.5 Proposed Modificatim Licensee's Submittal i

The licensee stated that modifications will be required to cross tie the BVPS Unit 1 and 2 electrical buses in order to provide the MC power I source to the blacked out unit. The modifications will include:

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1. Installat'on of breaker cubicles, breakers and additional cables ,

l to cross tie the e:nergency 4.16 kV buses, and I

2. Installation of breaker cubicles, breakers and cables to cross tie the normal 4.16 kV buses between the units.

1 Procedure changes to address load snedding, energization of the blacked out unit's buses from the MC power source and start-up of equipment required to cope with an SB0 event will be developed and implemented accordingly. The modifications and procedure changes will be completed-within two years after the NRC's notification in accordance with 10 CFR 50.63 (c)(3). The licensee added that, since the MC power source I involves cross-tieing buses between Units 1 and-2, installation and testing require refueling outages at both units. Therefore, the 1

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, schedule for completion of this modifications may. need to be extended, l

Review of Licensee's Submittal l

The proposed modification -(see: Figure 1) is a variation 'to an-acceptable )

configuration provided in NUMARC 87-00 Supplemental Questions / Answers  !

under Question C.1- (Samplo AAC Configurations). This modification-allows the licensee to power selected equipment. In the SB0 unit from one-of the EDCs in the NB0 unit.

3.6 Quality Assurance and Technical Specifications l

l The licensee did not provide any information on how th'e plant complies l with the requirement of RG 1.155, Appendices-A and B. . The licensee stated' I that all the SB0 equipment is covered by the normal plant quality, assurance program and technical specifications. The licensee needs' to verify that the SB0 equipment is covered by appropriate QA and technical specifications programs consistent with the guidancesof RG 1.155, Appendices-A and B.

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4.0 CONCLUSION

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Based on our review of the licenaee's submittals and the information available in the UFSARs for Beaver Valley Power Station Unit I and Unit 2, we find that the submittal conforms to the requirements of the SB0 rule and'the i guidance of RG 1.155 with the following exceptions:  ;

1

1. Alternate AC Power Source The licensee needs to demonstrate by a test that the AAC power source can power the selected equipment in the SB0 unit within one hour.

2. Compressed Air Our review indicates that the heat removal system at both-units j require local manual actions. A successful decay heat removal operation requires coordination of at least three operators: one in the control room, second one at the'ADVs, and the third at the AFW flow control valves. Therefore, the licensee needs to simulate this operational scenario and train the operators accordingly.

3. Effects of Loss of Ventilation The licensee's submittal only considers the areas with final temperature higher than 120'F as dominant areas of concern. The licensee does not commit to opening any cabinet doors even though I

the calculated final temperatures well exceed the normal operating range but below the 120'F limit. To comply with the NUMARC'87-00 Supplemental Questions / Answers, the licensee needs to provide procedures for opening the cabinet doors within 30 minutes in the control room and other areas containing temperature sensitive instrumentation, l

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4. Containment Isolation We identified the following' containment isolation vales that need closure capability to ensure appropriate containment integrity 1 during an S80 event:

Valves Status / Fail 111g Unil RSS-MOV 155A&B. OPEN/AS IS 12" - 1/2 RSS-MOV 155C&D OPEN/AS IS 12" '2 CHS-MOV 381 OPEN/AS IS 3" ./2 IAC-MOV 134 OPEN/AS IS 4" 2 The licensee needs to address the closure of these valves in the-appropriate procedure (s),

5. Quality Assurance and Technical Specifications The licensee did not address how the BVPS units are in compliance with the guidance provided in RG 1,155, Appendices A and B in its submittal, 26

_ _ _ . _ _ . ~ , . . . _ . _ . _ . _ . _ . , . . .

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5.0 REFERENCES

1. The Office of Federal Register, " Code of Federal Regulations Title 10-Part 50.63," 10 CFR 50.63, January 1, 1989..

2. U.S. Nuclear Regulatory Comission, " Evaluation of Station Blackcut. l Accidents at Nuclear Power Plants - Technical Findings Related to 1 Unresolved Safety Issue A-44," NUREG-1032, Baranowsky, P. W . June 1988.

3. U.S. Nuclear Regulatory Comission, " Collection and.. Evaluation of -

Complete and Partial Losses of Offsite Power at Nuclear Power Plants,"

NUREG/CR-3992, February 1985.

4. U.S. Nuclear Regulatory Comission, " Reliability of Emrgency AC Power System at Nuclear Power Plants,"= NUREG/CR-2989, July 1983.

5. U.S. Nuclear Regulatory Comission, " Emergency Diesel Generator Operating Experience, 1981-1983," NUREG/CR-4347,. December 1985.

6. U.S. Nuclear Regulatory Comission, " Station Blackout Accident Analyses (Part of NRC Task Action Plan A-44)," NUREG/CR-3226, May 1983.

7.. U.S. Nuclear Regulatory Comission Office of Nuclear Regulatory -

Research, " Regulatory Guide 1.155 Station Blackout," August 1988.

t

! 8. Nuclear Management and Resources Council, Inc., " Guidelines and Technical Bases for NUMARC Initiatives Addressing Station Blackout at Light Water Reactors," NUMARC 87-00, November 1987.

9. Nuclear Safety Analysis Center, "The Reliability of Emergency Diesel Generators at U.S. Nuclear Power Plants," NSAC-108, Wyckoff, H.,

September 1986.

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10. Sieber, J. D., letter to Document Control Desk of the U.S. Nuclear Regulatory Comission, " Beaver Valley Power Station, Unit I and 2, BV-1 l

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. _ .- . _._. . __ -. . . . _ - . . . _ _ ~

~

f o

• 'o *

,s Docket No. 50 334, License No. DPR 66, BV 2 Docket No. 50-412, Li:ense j

No. NPF-73, Response to Station Blackout Rule - 10 CFR 50.63," dated April 14, 1989.  !

11. Beaver Valley Power Station 'Jnit 1, Updated Final Safety Analysis j Report.

12. Beaver Valley Power Station Unit 2, Updated Final Safety Analysis ,

Report.

13. Sieber, J. D.,

letter to Document Control Desk of the U.S. Nuclear.

Regulatory Commission, " Beaver Valley Power Station, Unit No. I and No.

2, BV-1 Docket No. 50-334, License No. DPR 66 BV-2 Docket No. 50 412, License No. NPF 73, Supplemental Response to Station Blackout Rule - 10 CFR 50.'63," dated March 30, 1990,

14. Thadani, A. C., letter to W. H. Rasin of NUMARC, " Approval of NUMARC Documents on Station Blackout (TAC-40577)," dated October 7. 19Pa

15. Thadani, A. C.,

letter to A. Marion of NUMARC, " Publicly Noticed Meeting December 27, 1989," dated January 3, 1990 (confirming "NUMARC 87-00 Supplemental Questions / Answers," Decembe- 27,1989).

16. Rosa, F., Memorandum to Docket Concerning Beaver Valley Units 1 and 2,

" Meeting Summary - Meeting of February 22, 1990, on Station Blackout Issues (TAC 68510/68511)," Docket Nos. 50-334 and 50-412, dated March 6, 1990.

17. Tam, P.

S., Memorandum for, " Daily Highlight-Forthcoming Meeting with NUMARC on Station Blackout (SBO) Issues (TAC 40577)," dated April 25, 1990, (providing a Draft Staff Position Regarding Use of Emergency AC Power Sources (EDGs) as Alternate AC (AAC) Power Sources, dated April 24,1990),

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18. Russell, W. T., letter to W. Rasin of NUMARC, " STATION BLACKOUT," dated June 6, 1990,

19. Sieber, J. D.,

letter to Document Control Desk of the U.S. Nuclear Regu' . tory Comission, " Beaver Valley Power Station.. Unit I and 2, BV 1 Docket No. 50-334, License No. DPR 66, BV 2 Docket No. 50 412, license No. NPF 73, $80 Alternate AC Load Management " dated June 29, 1990.

20. Sieber, J. D., latter to Document Control Desk of the U.S. Nuci=&;-

Regulatory Comission, " Beaver Valley Power Station, Unit 1 and 2 BV 1 Docket No. 50 334, License No. DPR 66, BV 2 Docket No. 50 412, License No. NPF 73, SB0 - Alternate AC Load Nanagement," dated July 27, 1990.

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