ML20062C444

SER Re Station Blackout.Plant Does Not Conform W/Station Blackout Rule

ML20062C444
Person / Time
Site:	North Anna
Issue date:	10/18/1990
From:	Office of Nuclear Reactor Regulation
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ML20062C434	List: ML20062C431 ML20062C444 ML20064A972
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NUDOCS 9010310233
Download: ML20062C444 (11)

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REGARDINS STATION BLACKOUT VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION, UNITS 1 AND 2

1.0 INTRODUCTION

On July 21, 1988, the Code of Federal Regulations, 10 CFR Part 50, was amended to include a new Section 50.63, entitled " Loss of All Alternating Current Power," (Station Blackout). The station blackout (SB0) rule requires that each light-water-cooled nuclear power plant be able to withstand and recover from an SB0 of specified duration, requires licensees to submit information as defined in 10 CFR 50.63 and requires licensees to provide a plan and schedule for conformance to the SB0 rule. The SB0 rule further tequires that the baseline assumptions, analysis and related information be available for NRC review.

Guidance for conformance to the rule is provided by (1) Regulatory Guide (RG) 1.155 Station Blackout, (2) NUMARC 87-00, Guidelines and Technical Bases for NUMARC Initiatives Addressing Station Blackout at Light Water Reactors, and i

(3) NUMARC 87-00 Su 27, 1989 (pplemental Questions / Answers and. Major Assumptions dated December issued to the industry by NUMARC January 4,1990).

TofacilitatetheNRCstaff's(hereafterreferredtoasstaff)reviewoflicensee responses to the SB0 rule, the staff endorsed two generic response formats.

One response format is for use by plants proposing to use an alternate AC (AAC) power source, and the other format is for use

)y plants proposing an AC independent response.

The generic response formats provide the staff 91th a summary of the results from the licensee's analysis of the plant's SB0 coping capability. The licensees are expected to verify the accuracy of the results and maintain docu-mentation that supports the stated results.

Compliance to the SB0 rule is verified by a review of the licensee's submittal, an audit review of the sup-porting documentation as deemed necessary, and possible follow-up NRC inspec-tions to ensure that the licenset

's implemented the appropriate hardware and/

or procedure modifications that be required to comply with the SB0 rule.

l The licensee proposes to use existing emergency diesel generators (EDGs) as an AAC source and has submitted its response in the applicable generic response format. The licensee's initial responses were provided by a letter from W. R. Cartwright (Virginia Electric and Power C)mpany) to Document Control l

Desk of the U.S4 NuclearRegulatoryCommission(NRC),datedApril17,and April 20, 1989.

In addition, the licensee provided a response to the NUMARC 87-00 Supplemental Questions / Answers by a letter from W. L. Stewart to Document Control Desk, Nuclear Regulatory Commission, dated March 30, 1990. The licensee's responses were reviewed by Science Ap)lications International Corporation (SAIC) under contract to the NRC T1e results of the review are documented by a SAIC Technical Evaluation Report (TER),luation," dated l

SAIC-90/1370 North AnnaPowerStation,(Attachment 1),StationBlackoutEva Units 1 and 2 September 24, 1990

• Nuclear Management and Resources Council, Inc.

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2.0 EVALUATIO1 After reviewing the licensee's SB0 submittals and the SAIC TER, the staff concurs with the conclutions as identified in the SAIC TER (refer to Attachment 1 for details of the review).

Based on this review, the staff findings and recommenda-tions are sumarized as follows.

2.1 Station Blackout Duration The licensee has calculated a minimum acceptable SB0 duration of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> based on an offsite power design characteristic group of "P2", an Emergency AC configuration group "C", and an EDG reliability target of 0.95.

The "P2" grouping is based on an independence of offsite power classification of Group "I 1/2," a severe weather (SW) classification of Group "2" and an extremely severeweather(ESW) classification _ofGroup"4".

The staff disagrees with the licensee's classification of the independence of offsite power as Group "I 1/2".

As discussed in the attached TER, upon loss of a reserve station service transformer RSST-A, RSST-B or RRST-C, the only' method of energizing the second division would be by manually tieing the two emergency buses together. Thus, there is no automatic transfer of all the safeguard buses, and in addition the only method of manually powering the sec W division of the safeguard buses is by connecting the emergency buses together, which is unaccept-Able. Therefore, the independence of offsite power is Group "I3".

However, this does not result in a change to the required coping duration of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />.

2.2 Alternate AC (AAC) Power Source The licensee has proposed using the existing EDGs as an AAC power source to operate systems necessary for the required SB0 coping duration of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> and recovery therefrom.

2.2.1 General staff position on AAC power sources The definition in 10 CFR 950.2, RG 1.155 and NUMARC 87-00 define AAC power source 1

in terms of four attributes:

(1) connections to the offsite or the onsite AC power systems, (2) minimum potential for common cause failure with offsite or the onsite emergency AC power sources, (3) timely availability, and (4) power re-quired capacity and reliability. More specifically, in regard to the fourth attribute, the SB0 rule reads as follows:

"(4) Has sufficient capacity and reliability for operation of all systems required for coping with station blackout and for the time required to bring and maintain theplantinsafeshutdown(non-designbasisaccident)."

In view of the variety of types, capacities and capabilities of. power sources proposed as AAC sources by various licensees,~the staff has characterized pro-posed AAC power sources as being either optimum, fully capable or partially capable. This characterization, which relates only to the capacity attribute l

cited above, was necessary in order to facilitate the staff review of licensee responses to the SB0 rule.

It does not invalidate or revoke any of the require-ments or guidance applicable to AAC power sources.

1

. An optimum AAC power source design is one that is capable of powering simultan-eously both safety trains of normal safe shutdown systems and equipment.

Such a design, following actuation of the AAC source, would provide completely redundant normal safe shutdown capability during an SB0 and recovery therefrom from the main control room.

A fully capable AAC power source design is one that is capable of powering at least one complete safety train of normal safe shutdown systems and equipment.

This includes decay heat removal, battery charging, HVAC (heating, ventilation and air conditioning), emergency lighting, and the associated controls and in-strumentation.

Thus, although redundant capability is not available, a fully capable AAC source would enable attainment of safe shutdown during an SB0 and recovery therefrom from the main control room.

A minimally capable AAC power source design is one that is not capable of power-ing all (or any) normal safety train related safe shutdown equipment; but it is capable of powering specific equipment that, in conjunction with extensive manual operator actions both inside and outside of the control room, is critical for attaining safe shutdown during an SB0.

Appendix R diesels proposed as an AAC source are examples of minimally capable AAC sources.

With this design, oper-ability of the main control room could not be assured unless the batteries were sized to operate for the SB0 duration, or b:ttery charging capability was pro-vided by the AAC source.

2.2.1.1 EDGs used as AAC power sources The guidance on the use of existing EDGs as AAC power sources is documented in the SB0 rule, 10 CFR 550.63, RG 1.155 Position C.3.3.5 and NUMARC 87-00 (Section2.3.1(3). This guidance is further explained in NLHARC 87-00 Supplemental Questions and Answers dated December 27, 1989, under questions 3.4 and B.3.

The SB0 rule states:

"At multi-unit sites, where the combination of emergency ac power sources exceeds the minimum redundancy requirements for safe shutdown (non-DBA) of all units, the remaining emergency ac power sources may be used as alternate ac power sources provided they meet the applicable requirements."

The rule statement requires minimum redundancy. This means that in order to qualify as an AAC source, there must be an-EDG available in the non-blackout (NBO) unit that is in addition to the number of EDGs required to meet the min-imum EDG redundanc of offsite power (y req) event.uirement for powering a normal safe shutdown for a loss LOOP Thus, the EDG's in a two-unit site with two dedicated EDG's per unit would not qualify as AAC sources because the two EDGs per unit just meet the minimum redundancy requirement, i.e., there is no excess EDG.

However, there are some plants at two-unit sites which just meet minimum redun-dancy, but where each EDG is of sufficient capacity to fully power all the normal LOOP loads of the NB0 unit, and also has sufficient excess capacity for powering the required safe shutdown loads of the SB0 unit.

In recognition of the existence

P 4-of this type of situation, the staff has interpreted the excess EDG redundancy requirement of the SB0 rule to allow EDGs just meeting the minimum EDG redundancy requirements to qualify as AAC sources on the basis of excess capacity, provided the other applicable requirements for AAC sources are also met.

The NRC's basic position on the use of EDGs as AAC' power sources on the basis of excess capacity is that such excess capacity should not be attained by load shed-ding in the NB0 unit which results in a degradation of its normally available safe shutdown capability for the LOOP condition.

Any actions that would add to the burden of operators that are already in a high stress environment, such as itsd switching or disablement of information readouts or alarms in the control room, are considered to be a degradation of normal safe shutdown capability for LOOP in the NB0 unit.

The staff position is therefore that the normal equipment compliment should remain available with ad w ate EDG capacity for use should it become necessary. The NB0 unit should han the capability for hot shutdown / hot standby forced cooling, cooldown and depressurization as required.

While addi-tional events are not explicitly being postulated, it is not prudent to diminish the capability of the NB0 unit to mitigate problems should they arise.

It is not in the interest of safety to reduce the capability to handle various 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 capabil-ity to respond to its own potential problems.

Therefore, a multi-unit site with-the dedicated EDGs just meeting the minimum redundancy requirement but not having the excess capacity defined above for qualifying as an AAC source does not meet the SB0 rule AAC source option requirements.

Further measures are required, such as a separate AAC source or a coping analysis, which shows the plant can cope with and recover from SB0 for the required duration.

2.2.1.2 Connectability of AAC power sources The basic criteria governing the connectability of an AAC power source are con-tained in 10 CFR 50.2 (the AAC source'should be connectable to but normally not connected to the offsite or onsite emergency AC power systems),10 CFR 50.63, (SB0 should not assume a concurrent single failure or design basis accident),

and in Appendix A of 10 CFR Part 50 (the single failure criterion and the independence r9quirements apply to the NB0 unit). Therefore, in a one-unit site, as a minimum, an AAC source need only be connectable to one set of safe shutdown equipment, regardless of whether that equipment is part of a safety train or not, or whether the AAC source is an excess redundancy EDG or an independent power source.

However, at a two (or more) unit site where the EDGs meet the AAC source excess redundancy criterion, one intertie circuit between units is acceptable provided it is separately connectable to each safety (EDG) bus in both units.

This follows from the application of the above criteria and the assumptions that must be taken that an SB0 can occur in either unit, and that the single failure in the NB0 unit can be on either one of its EDGs or on its respective safety bus.

l l

. 2.2.2 Proposed AAC power source The North Anna Power Station presently has four EDGs, with two EDGs dedicated to each unit.

The licensee proposes to install additional switchgear and electrical connections between the 4160V emergency buses of Unit-1 and Unit 2 so that either one of the two EDGs of NB0 unit could serve as an AAC power source for the SB0 unit during an SBO.

The licensee's submittal states that the EDG/AAC source is available within I hour of the onset of the SB0 event, and has sufficient capability to provide power for the safe shutdewn of both units for an 8-hour SB0 duration.

However, a July 2,1990, telefax to'the NRC from the licensee, showing a preliminary tab-ulation of loads on the AAC source (NB0 and SB0 unit loads), did not include-several of the normal LOOP loads on the NB0 unit.

Subsequently, during a tele-con on July 3,1990, the licensee discussed with the staff a proposed load manage-ment scheme on the NB0 unit. The purpose of this load management scheme was to eliminate loads from the EDGs such that they could qualify as AAC sources on the basis of excess capacity.

The staff-told the licensee that such a load manage-ment scheme on the NB0 unit did not conform to the SB0 rule.

By letter dated August 1, 1990, the licensee subnitted a revised tabulation of the AAC source loadings (NB0 and SB0 unit loads) for the Surry Power Station.

No similar tabu-lation was presented for the North Anna Power Station. However, the staff's understanding is that the August 1,1990 tabulation for Surry Power Station is also applicable to North Anna Power Station. The staff concluded that the Surry Power Station load management scheme was not consistent with the SB0 rule.

Therefore, based on the July 2,1990, preliminary tabulation of the SB0 loads for North Anna and the revised August 1,1990, tabulation for Surry (assumed to be the same for North Anna), the staff concludes that the North Anna Power Station EDGs do not have the excess capacity available to qualify as an AAC source.

In addi-tion, the licensee's of AAC power sources) proposed AAC power source configuration (connectability does not conform to an acceptable configuration as-pro-vided in NUMARC-8700 and NUMARC 87-00 Supplemental Questions / Answers under question C.1 and to the guidance of Section 2.2.1.2 above.

After reviewing the SAIC TER and the licensee's proposed actions for crediting existing NB0 unit EDGs as an AAC source, the staff has determined that the pro-posed AAC source does not meet the requirements of 10 CFR 650.63.

Recommendation: The licensee should undertake further measures such as provid-ing an independent AAC power source or a coping analy:,is which shows that the plant can cope with and recover from an SB0 for the required duration independ-l-

ent of AC power.

2.3 Station Blackout Coping Capability The characteristics of the following plant systems and components were reviewed to assure that the systems have the availability, adequacy and capability to achieve and maintain safe shutdown and recovery from an SB0 for an 8-hour coping duration.

. 2.3.1 Condensate inventory for decay heat removal The licensee states that it has been determined using NUMARC 87-00 methodology that 103,024 gallons of condensate water are required for decay heat removal for l

8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. This is enveloped by the minimum emergency condensate storage tank (CST) level allowed by the Technical Specifications (TS) of 110,000 gallons.

After reviewing the licensee's submittal and the SAIC TER, the staff agrees with the licensee's assessment that the plant has adequate condensate inventory for an 8-hour SB0 duration.

In addition, the excess inventory available in the CST is available for SB0 recovery.

However, the licensee needs to assess how the decay heat removal function will be accomplished without the benefit of instrumen-tation and DC power required for the electrical systems and controls in the blacked-out unit af ter the battery is discharged in I hour, 2.3.2 Class 1E battery capacity The licensee stated that a battery calculation has been performed pursuant to NUMARC 87-00 methodology to verify that the Class 1E batteries have suffi-cient capacity to meet the SB0 loads for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.

Further, the AAC source would be available to power the battery charger (one de train) after 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> following the onset of the SBO, The licensee did not specifically state that both battery banks of the NB0 unit would be powered by battery chargers during the SB0 event. The staff's review shows that the licensee's proposed AAC power source does not have the required excess capacity to qualify as an ACC source in accordance with the requirements of 10 CFR 550.63, and therefore cannot be credited toward charging the batteries.

It appears that the batteries will be discharged without charging and there is no assurance that the decay heat removal function can be maintained without the control room instrumentation and DC power for electrical systems and controls in the SB0 unit for the required duration.

Recommendation:

The licensee should provide a battery of sufficient capacity to power all normal battery-backed monitoring and electrical systems and controls for the required SB0 duration and recovery therefrom, or provide battery charging from an acceptable AAC power source.

2.3.3 Compressed air The licensee has stated that all air-operated valves needed for the I hour SB0 coping duration can be either operated manually or have_ sufficient backup sources of power. Also, the licensee has indicated that an air compressor will be avail-able within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after the electrical' cross-connect is established to supply power to the SB0 unit from the NB0 unit.

However, the proposed cross-connect-for the North Anna Power Station does not meet the SB0 rule guidance (see Section 2.2.2), and therefore it cannot be assumed that the compressor will be available for the NB0 and SB0 unit after 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. North Anna has a common com-pressed air system for Units 1 and 2 and one instrument air compressor per unit each powered from an emergency bus.,In order to supply power to at least one compressor in either unit, the licensee needs to commit to have a cross-connect

. between transfer buses D and E.

This cross-connect would enable the safety buses 1J and 2H to be connected to an available EDG in either unit, a cross-connect already exists between safety buses IH and 2J to enable these buses to be connected to an available EDG in either unit. There are separate air bottles or a nitrogen supply on critical valves to allow control without the air compressor during the first hour.

After reviewing the information provided by the licensee and the SAIC TER - the staff agrees with SAIC assessment that once the recommended cross-tie between.

transfer buses D and E is installed, adequate compressed air will be available to support the air-operated valves. However, the North Anna Power Station does not have a qualified AAC power source, and therefore while the recommended cross-tie between buses D and E resolves the compressed air issue, it does not resolve the SB0 issue.

2.3.4 Effects of loss of ventilation The licensee identified several areas that require forced ventiletion.

These include the control room (common for Units 1 and 2), the emerger.cy switchgear rooms, the charging pump cubicles and auxiliary feedwater pump room.

The licensee calculated 8-hour steady-state temperatures as shown below using non-applicable NUMARC 87-00 methodology.

- Control room 181'F

- Emergency switchgear room 153'F

- Charging pump cubicles 300*F

- AFW pump room 175'F The licensee stated that existing ventilation (chiller, air handler, and associ-ated pumps) for the control room and emergency switchgear rooms would be provided within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.

No information was provided as to what steps would be taken to ensure that the control room and switchgear rooms do not exceed 120'F during the first hour of the SBO. The licensee did not state that.their procedures would include a provision to open the cabinet doors in the control room within 30 minutes of onset of SBO.

The licensee also stated that ventilation fans and flexible ducting installed for Appendix "R" will be used to maintain the charging pump cubicles to less than 120'F. This ventilation would be provi<t ' within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />.

The licensee stated that existing ventilation would be utilized to lower the temperature in the AFW pump room to an acceptable temperature of 120*F. Since no information was given on how this ventilation would be provided in the AFW room, the licensee needs b furnish specific details on anticipated operator actions in the AFW pump room to justify the acceptability of a 175'F environment.

These details need to specifically address the ability of the operator to ade-l quately perform his functions in this room during an SB0 event.

l The licensee did not provide an evaluation of the heat-up calculations performed, if any, for the dominant areas of concern including the control room, emergency switchgear room, charging pump cubicles and AFW pump room for the first hour of an SB0 event. Also, the licensee needs to address the SB0 equipment inside the containment concerning the effects of loss of ventilation.

. The licensee's analyses presumably used NUMARC 87-00 methodology for the heat-up calculations.

However, NUMARC methodology is not appropriate for an 8-hour cop-ing duration.

Also, the licensee's proposed method of limiting the heat-up in some of the dominant areas of concern depends on the excess capacity of the NB0 unit EDGs used as an AAC source.

However, the staff has determined that the NB0 unit EDGs do not have excess capacity to qualify as an AAC source.

Recommendation:

The licensee's analyses assume that an AAC source will be avail-able to power HVAC equipment of the SB0 unit within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. However, the staff has determined that the existing EDGs at the North Anna plant do not have the excess capacity to qualify as an AAC source in accordance with the SB0 rule re-quirements. Therefore, the licensee should provide an acceptable AAC source, or provide other means to provide the necessary HVAC during an SBO.

The licensee should perform the heat-up evaluation for the dominant areas of concern including control room, switchgear rooms, AFW pump room, and charging pump cubicles. The licensee should verify that there is reasonable assurance of equipment oper-ability and habitability for the operator manual actions during the first hour of the SB0. The licensee should maintain these analyses and verification as part of the SB0 package supporting the SB0 rule response. Also, the licensee should include in their SB0 procedures a provision to open the control room cabinet doors within 30 minutes after the onset of an SBO.. Additionally, licensee should provide evaluation for the SB0 equipment inside containment con-cerning the effects of loss of ventilation for the required SB0 duration.

2.3.5 Containment isolation The licensee reviewed the plant list of containment isolation valves (CIVs) to verify that valves which must be capable of being closed or operated (cycled) during an SB0 can be positioned (with indication) independent of the blacked-out unit's power supplies.

The licensee stated that no plant modifications are necessary to insure containment integrity during an SB0. The staff agrees with the licensee's analysis and concludes that there is reasonable assurance that appropriate containment isolation can be achieved and maintained during an SB0.

2.3.6 Reactor coolant inventory The licensee used a Surry Power Station specific analysis which bounds the reactor coolant system at North Anna to assess that the reactor coolant-inventory was adequate to prevent core uncovery during the first hour of an SB0. Within that time, a charging pump in the NB0 unit would be started to provide make-up flow to the RCS of both units through a cross-connect line, and would provide l

sufficient flow to ensure core cooling for the SB0 period. The staff agrees that the one charging pump should have sufficient capacity to prevent core uncovery of the blacked out unit and to maintain RCS inventory at the NB0 unit provided that the NB0 unit is kept at hot standby during the SB0 event.

However, the licensee needs to add an acceptable AAC source to power the charging pump and charge the station battery or describe how the inventory above the core will j

be monitored and muintained without the benefit of instrumentation or DC power in the blacked-out unit after 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> when the battery becomes discharged.

t Recommendation:

The licensee should provide an acceptable independent AAC source of sufficient capacity and capability to provide power to the supporting systems l

to monitor and maintain adequate RCS inventory.

1

. 2.4 Procedures and training The licensee has stated that procedures are in place to address many of the SB0 coping requirements, and these procedures will be revised to address the AAC method of coping with an SB0. The licensee did not specifically address the training requirement to implement the modifications or associated procedures.-

The proposed procedure modifications were not reviewed by the NRC staff, but the staff expects the licensee to maintain and implement these procedures, including any others that may be required as part of the revised response, to ensure an appropriate response to an SB0 event. Although personnel training requirements for an SB0 response were not specifically addressed by the licensee's submittal, the staff expects the licensee to implement the appropriate training to ensure an effective response to an SB0.

2.5 Proposed Modifications The licensee proposes to add a Class 1E crosstie connection between the 4160V buses IJ and 1H of Unit 1.

The licensee stated that this would allow power to be transferred between units from any one of the EDGs.

The staff finds this proposed configuration unacceptable because a failure _of the inner safety bus (1H or 2J) of the NB0 unit would prevent transfer of power to the blacked-out unit from the NB0 unit.

In response to the above-stated staff ccncern, the licensee proposed in their August 1,1990 submittal for the Surry Power Station an additional non-safety grade crosstie between the non-safety outer transfer buses D and E.

3 The North Anna Power Station was not specifically addressed in the August 1,1990, submittal and the staff does not know if a similar crosstie would also be in-stalled at the North Anna Power Station.

This cross-tie modification should be implemented at the North Anna station, in order to have an acceptable crosstie configuration for using EDGs as AAC power sources.

However, since the EDGs do not meet the excess capacity requirements of the SB0 rule, the staff concludes that none of the EDGs qualify as an acceptable AAC power source.

The licensee also noted that breaker control and protective relay modifications will be required to allow connections of the buses in the manner described. No modifications to other plant equipment are described.- However, in view of the staff positions as identified in recommendations documented in this SE, other modifications may be required.

Recommendation:

The licensee shoulo provide an AAC source that meets the re-quirements of the SB0 rule or an alternative method for coping with.an SB0.

A full description of the proposed modifications-including the. nature and objectives of the required modifications to meet the SB0 rule and a proposed schedule for implementation should be provided.

2.6 Quality Assurance (QA) and Technical Specifications (TS) l The licensee did not provide information-regarding QA programs and TS for SB0 equipment. TS for the SB0 equipment are currently being considered generically by the NRC in the context of the Technical Specification Improvement Program l

i

. and remain an open item at this time. However, the staff would expect that the plant procedures will reflect the appropriate testing and surveillance requirements to ensure the operability of the necessary SB0 equipment.

If the staff later determines that a TS re arding the SB0 equipment is warranted, the licensee will be notified of the im lementation requirements.

Recommendation:

The licensee should verify that the SB0 equipment is covered by an approprfate QA program consistent with the guidance of RG 1.155.

Further, this verification should be documented as part of the package supporting the SB0 rule response.

2.7 EDG Reliability Program The licensee stated that the EDG target reliability of 0.95 is to be maintained, however, no information was provided as to how this would be accomplished.-

Recommendation:

It is the staff's position that an EDG reliability program should be developed in accordance with the guidance of RG 1.155 Section 1.2.

Confirmation that such a program is in place or will be implemented should be included in the documentation that is to be maintained by the licensee in support of the SB0 submittals.

2.8 Scope of staff review The SB0 rule (10 CFR 50.63) requires licensees to submit a response containing specifically defined information.

It also requires utilities "---- to have baseline assumptions, analyses and related information used in their coping evaluation available to NRC."

The staff and its contractor did not perform a detailed review of the proposed procedure modifications which are scheduled for later implementation. Therefore, based on our review of the licensee's SB0 submittals and the FSAR, we have identified the following areas for focus in any follow-up inspection or assessment that may be undertaken by the NRC to i

i further verify conformance with the SB0 rule.

i a.

Hardware and procedural modifications, b.

SB0 procedures in accordance with R.G. 1.155, Position 3.4, and NUMARC 87-00, Section 4, Operator staffing and training to follow the identified c.

actions in the SB0 procedures, d.

EDG reliability program meeting, as a minimum, the guido11nes of RG 1.155, Equipment and components required to cope with an SB0 are e.

incorporated in a QA program that meets the guidance of RG 1.155, Appendix A, and f.

Actions taken pertaining to the specific recommendations noted in-the SE.

>r

. Additional areas may be identified following staff review of licensee's revised response to the SB0 rule.

3.0

SUMMARY

AND CONCLUSIONS The staff has reviewed the licensee's response to the SB0 rule (10 CFR 50.63) and the Technical Evaluation Report prepared by the staff's consultant, Science Applications International Corporation.

Based on the staff's review of the l

licensee's submittals and the SAIC TER, the staff finds that the North Anna Power 4

Station does not conform with the SB0 rule and the guidance of R.G. 1.155, and l

therefore recommends that the licensee re-evaluate the areas of concern that have been identified in this SE. Guidance for the licensee to review and imple-ment the staff's recommendations is provided in RG.I.155, NUMARC 87-00 and the supplementary guidance (NUMARC 87-00 Supplementary Questions / Answers; NUMARC l

87-00 Major Assumptions) dated December 27, 1989, which was issued to the in-dustry by NUMARC on January 4,1990.

The staff's concerns that are identified-in this SE should be addressed by the licensee,- and a revised response submitted i

to the NRC within 60 days. The licensee is expected to ensure.that the baseline assumptions of NUMARC 87-00 are applicable to the North Anna Power Station.

1 Also, the licensee should maintain all analyses and related information in the documentation supporting the SB0 submittal for further inspection and assessment-as may be undertaken by the NRC to audit conformance with the SB0 rule..

}

Dated: October 18, 1990 i

Principal Contributor:

A. Toalston l

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