IR 05000334/1993080

Insp Repts 50-334/93-80 & 50-412/93-80 on 930830-0903.No Violations Noted.Major Areas Inspected:Adequacy of Programs, Procedures,Training,Equipment & Sys for Implementing SBO

ML20059F614
Person / Time
Site:	Beaver Valley
Issue date:	10/27/1993
From:	Durr J, James Trapp NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
To:
Shared Package
ML20059F606	List: IR 05000334/1993080 ML20059F603
References
50-334-93-80, 50-412-93-80, NUDOCS 9311050015
Download: ML20059F614 (20)

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U. S. NUCLEAR REGULATORY COMMISSION

REGION I

STATION BLACKOUT TEAM REPORT t

REPORT NO /93-80 50-412/93-80 DOCKET NO LICENSE NO DPR-66 .;

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NPF-73

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LICENSEE: Duquesne Light Company ,

One Oxford Center  ;

301 Grant Street Pittsburgh, PA 15279 .

FACILITY: Beaver Valley Power Stations Units 1 & 2 >

INSPECTION DATES: August 30 - September 3,1993 f INSPECTORS: R. Bhatia, Reactor Engineer, RI A. Pal, Electrical Engineer, NRR L. Scholl, Reactor Engineer, RI D. Shum, Reactor Systems Engineer, NRR TEAM LEADER: M 'N'

James M. Trapp, Team Leader, Date ,

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Engineering Branch, DRS

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APPROVED BY: , J/s _,,AM /cp[y[9J

[/acque Ik Dtirr, Chief, EnWeering / DatV V Branch, Division of Reactor Safety 9311050015 931028 PDR ADOCK 05000334 G PDR

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SUMMARY This was the first station blackout (SBO) inspection conducted by the Region I staff. The team used a draft temporary instruction as guidance for conducting this inspection. _ The actions taken to implement the station blackout rule are important because many of the systems reqmred for decay heat removal and containment cooling are dependent on the availability of alternating current (ac) power. In the event of a station blackout, relatively few systems that do not require ac power are depended upon to remove decay heat, until ac power is restored. The consequences of the failure of this equipment to operate could be severe. The objective of this inspection was to verify the adequacy of the programs, procedures, training, equipment and systems for implementing the station blackout rul Specifically, the team reviewed the coping duration analysis, station blackout coping systems, station blackout procedures and training, and plant modifications implemented in response to the station blackout rul The coping duration analysis that determined that the Beaver Valley Power Station was a 4-hour coping plant was technically sound. The documentation that supported this analysis was detailed and provided an adequate basis to support the overall conclusio The calculations and supporting documentation that established the availability of the station blackout systems to mitigate the consequences of a SBO event were thorough. The team-concluded that the station blackout systems are adequate to cope with a station blackout of a 4-hour duratio The station blackout procedures provide detailed instructions for the operation of systems and equipment during a station blackout event. The station blackout procedures were thorough and of high quality. The station blackout training provided to licensed and nonlicensed plant operators was thorough and provided the operators with the information necessary to mitigate the consequences of a station blackout even The team identified discrepancies in the emergency diesel generator loading calculations for an SBO event. The revised loading calculation determined that a Unit 1 emergency diesel generator load of approximately 2844 kW was required +o ensure that both units could be brought to and maintained in safe shutdown during a SBO cvent. The team noted that this load was in excess of the minimum required 18-month surveillance test load for the Unit I diesels. The engineering staff stated that action would be taken to ensure that the diesels were periodically tested at a load equal to or greater than the required operating loads during a station blackout even The cross-tie modification design and supporting documentation were of high quality. The post modification testing of the cross-tie was acceptable, iii

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In general, the team determined that the overall responses taken to implement the station blackout rule were excellent. The inspection included assessments in several functional areas such as operations, engineering and training. Strengths were noted by the team in each area reviewed. The team determined that appropriate actions had been implemented to satisfy the station blackout rule requirement !

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DETAILS INSPECTION BACKGROUND / OBJECTIVE A station blackout (SBO) is the complete loss of altereating current (ac) electric power to the essential and nonessential switchgear buses in a nuclear power plant. Because many safety systems required for reactor core decay heat removal and containment heat removal are dependent on ac power, the consequences of a station blackout could be severe. To address this concern, the Commission issued the Station Blackout Rule 10 CFR 50.63, " Loss of All Alternating Current Power." To provide guidance on acceptable methods for meeting the requirements of the station blackout rule, the NRC issued Regulatory Guide 1.155, " Station Blackout." Concurrent with the development of the regulatory guide, the Nuclear i

Management and Resource Council (NUMARC) developed guidelines and procedures for assessing station blackout coping capability and duration. NUMARC 87-00, " Guidelines and Technical Bases for NUMARC Initiatives Addressing Station Blackout at Light Water Reactors," documents the NUMARC recommendations. The team used these documents for inspection guidanc Duquesne Light Company provided the NRC the Beaver Valley Power Station (BVPS)

response to the station blackout rule in a letter dated April 14, 1989. A supplemental response to this letter was provided on March 30,1990. Two additional letters, dated June 29,1990, and July 27,1990, provided additional information regarding the alternate ac load management. The NRC issued a safety evaluation report (SER) of the Beaver Valley Power Station response to the station blackout rule on August 30,1990. The SER presented several recommendations, but concluded that the BVPS conformed with the SBO rule, and the guidance of both Regulatory Guide 1.155 and NUMARC 87-00. The licensee responded to the SER recommendations in two letters to the NRC, dated December 20,1990, and June 21,199 In response to the Station Blackout Rule, Beaver Valley installed a cross-tie to provide power to the blacked-out unit from the nonblacked-out unit. The excess capacity of the existing emergency diesel generator, from the nonblacked-out unit, would be used as an alternate alternating current (AAC) power source. Testing has determined that the AAC power source can be placed in-service within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> after a station blackou l

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This was a pilot station blackout inspection conducted by the Region I staff. The team used l a draft temporary instruction as guidance for conducting this inspection. The objective of this inspection was to verify the adequacy of the programs, procedures, training, equipment and systems for implementing the station blackout rule. Specifically, the team reviewed the l

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coping duration analysis, station blackout coping systems, station blackout procedures and training, and plant modifications implemented in response to the SBO rule. The inspection report is divided into four sections providing the team findings for each area reviewe I i

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2 DETAILED INSPECTION FINDINGS Coping Duration Analysis The station blackout rule required that systems provide sufficient capacity and capability to ensure that the reactor core is cooled and appropriate containment integrity is maintained in the event of a station blackout for a specified duration. The specified duration.was calculated based on factors such as the offsite power design characteristics, emergency alternating current (ac) power supply configuration, and the emergency diesel generator reliability. A minimum acceptable station blackout (SBO) duration of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> was calculated for the Beaver Valley Power Station. The team verified selected factors which were used to determine the station blackout duratio The licensee provided the proposed 4-hour station blackout duration in a letter to the NRC, dated April 14, 1989. The NRC reviewed the proposed SBO duration and agreed with the licensee's evaluation as documented in the NRC safety evaluation report. The 4-hour station blackout duration was based on an offsite power design characteristic group of "P2," an emergency ac configuration group of "C," and an emergency diesel generator reliability target selection of 0.97 The offsite power design characteristic group "P2" was derived from an independence of offsite power characteristic of "13," severe weather group "2," extremely severe weather group of "1," and an expected loss of offsite power of less than 1 per 20 years. The team reviewed plant documentation to verify that these characteristic were appropriat The emergency diesel generator reliability data was reviewed. The reliability values, for the last 100 valid start and load run demands for the Unit 1, Number 1 and 2 diesel generators, were 0.99 and 1.00, respectively. The reliabi'ity data fr both the Unit 2 diesels indicated no start and load run failures and, therefore, the diesel relibility for both the diesels was 1.0. Based on a review of the diesel reliability data, the team determined that the selection of a 0.975 emergency diesel generator reliability target value was appropriat The team concluded that the calculated minimum acceptable station blackout duration of 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> was in accordance with the NUMARC guidelines and was acceptabl .2 Station Blackout Coping Systems 2.2.1 Auxiliary Feedwater and Steam Relief To establish reactor decay heat removal, certain auxiliary feedwater and steam relief system valves require local operation during a station blackout event. The procedures which provided instructions on the manual operation of these valves and the training provided to

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plant operators on the operation of these valves were reviewed. The team also reviewed calculations that determined the peak temperatures in the locations where manual equipment operations were required to determine if these areas were accessible and habitable during a station blackout even The auxiliary feedwater system flow control valves and the atmospheric steam dump valves require manual operation during a station blackout event. These valves are air-operated at Unit 1 and have electro-hydraulic operators at Unit 2. Compressed air and electric power would not be available to operate these valves during the first hour of a SBO event and,-

therefore, manual operation of these valves would be required. The emergency operating procedures provided detailed instructions for locally operating these valves. In addition, operator aids which provided instructions describing the manual operation of the Unit 2 electro-hydraulic valves are located at each valve. The licensee had provided training on the manual operation of the auxiliary feedwater system flow control valves and the atmospheric dump valves. The team also verified that plans and communication equipment were available for the coordination between the operators in the control room and those locally operating valves during a SBO even The calculated peak temperatures in the vicinity of the auxiliary feedwater system flow control valves and the Unit 2 atmospheric steam dump valves were less than 120 F. The calculated peak temperature in the vicinity of the Unit 1 atmospheric dump valves was approximately 133.3 F. The team reviewed the calculations and found them to be acceptable and in accordance with the methodology of NUMARC 87-00. The manual operation of the atmospheric dump valves requires approximately 5 to 10 minutes to perform. These valves - '

would be operated on an intermittent basis and an operator would not be continuously stationed in this area during a SBO event. Based on prior experience with personnel working in areas with elevated temperatures, the licensee determined that the intermittent operation of these valves would not present a personnel hazar The team concluded that the procedures provided for operating the auxiliary feedwater and steam relief systems during a station blackout event were appropriate. The auxiliary feedwater flow control valves and the atmospheric steam dump valves would be accessible to plant operators during a station blackout event and temperatures in the vicinity of the valves would not prevent local operatio .2.2 Station Battery Capacity The team reviewed the station battery capacity calculations to assure that the battery capacity was adequate to provide power to required station blackout equipment for I hour. The 1-hour duration is based on the selection of a 1-hour alternate ac power source (a battery charger would be restored within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />).

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The team verified that the battery sizing calculation included an appropriate aging factor, temperature correction factor, and a design margin of 5%. The team also verified that the input current requirements for the uninterruptible power supply loads were appropriate. The team determined that the battery terminal voltage profile calculation had correctly considered the aging factor, the temperature correction factor, and the design margi The team concluded that the battery capacity was adequate to power the SBO loads for a 1-hour duration. A battery charger for one division of equipment would be powered by the alternate ac power source within I hour following a SBO even .2.3 Effects of Loss of Ventilation During a station blackout event, certain ventilation systems would be lost in areas containing equipment required to mitigate the consequences of a station blackout. The station blackout rule required that licensees identify areas that contained equipment required to operate during a station blackout and were susceptible to a significant heat-up follow'mg the station blackou These areas are the dominant areas of concern. A review of the station blackout mitigation equipment located in these areas is required to assure operability during a station blackout event. The team reviewed the heat-up rate calculations that identified the dominant areas of concern and reviewed the reasonable assurance of operability for equipment located in these areas. The station procedures that provide compensatory measures for the loss of ventilation systems during a station blackout event were also reviewed by the tea The team verified that the heat generation rate calculations for various equipment, piping and components for the areas containing SBO equipment had been performed in accordance with the NUMARC 87-00 guidance. The calculated heat generation rates were used to determine the peak temperature in the areas containing SBO equipment. All the peak area temperatures, with the exception of the Unit 1 main steam valve room, were less than 120 F. Therefore, only the Unit I main steam valve room was identified as a dominant area of concern. The licensee's bases for the reasonable assurance of operability for station blackout equipment located in the Unit 1 main steam valve room were acceptabl The peak temperature calculation for the Unit I main steam valve room assumed that the louvers located in the ceiling of the room were opened. The team verified that the emergency operating procedures required opening these ventilation louvers. The team also verified that the station blackout emergency operating procedures required the opening of control room cabinet doors within 30 minutes after a SBO even The team concluded that the calculations that identified the dominant areas of concern were technically sound and that the equipment located in the dominate area of concern had a reasonable assurance of operability. In addition, the team determined that the station blackout emergency operating procedures had sufficient provisions to mitigate the >

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2.2.4 Containment Isolation Valves The team verified that the containment isolation valves that required manual operation during a SBO event had been correctly identified and that station procedures required the closure of these valve l The NRC station blackout safety evaluation report identified several containment isolation j valves that required closure during a SBO event. The safety evaluation recommended that i the licensee review the operational features of these valves and ensure that the SBO procedures provided the means for proper control of these valves to assure containment i integrity for the required SBO duration. The licensee's evaluation of containment isolation j valves was documented in the " Station Blackout Shutdown Capability Summary," Appendix ;

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A. The evaluation provided a list of all the containment isolation valves and the basis for not requiring manual closure of the valve during a station blackout in accordance with the NUMARC 87-00, Section 7.2.5 criteria. The Unit I and Unit 2 reactor coolant pump seal water return valves (MOV-lCH-381 and 2CHS*MOV-381) and the Unit 2 the instrument air suction valve (2IAC*MOV-134) were identified as the three valves requiring manual l

operation. The recirculation spray pump suction isolation valves (RSS-MOV-155A&B Unit 1 and 2RSS*MOV-155A, B, C, D Unit 2) were determined by the licensee not to require

manual operation. The basis for this conclusion was that the valves were located in a closed system that is not expected to be breached during a SBO event. This conclusion was documented in a letter to the NRC, dated June 21,1993. The station blackout emergency l operating procedures provided steps for manually closing the required containment isolation valves. The Unit I reactor coolant pump seal return valve (MOV-lCH-381) was required to

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be closed in Emergency Operating Procedure ECA 0.0, " Loss of All AC Power," Step 1 The Unit 2 reactor coolant pump seal water return valve (2CHS*MOV-381) and the instrument air suction valve (21AC*MOV-134) were required to be closed in Procedure ECA 0.0, Steps 29b and 18C.2, respectivel The team determined that the licensee had correctly identified those valves that require !

manual closure in accordance with the NUMARC 87-00 guidance. The valves that require closure during a station blackout event were directed to be closed in accordance with the station blackout emergency procedures. The team concluded that the actions taken to provide containment integrity during a SBO event were appropriat .2.5 Condensate Inventory The team reviewed the licensee's calculations which demonstrated that the demineralized l i

water storage tank had adequate capacity for decay heat removal and for the cooldown of the reactor in accordance with the emergency operating procedure !

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The condensate inventory calculation indkated that 87,604 gallons of condensate would be required to remove decay heat for 4 hocrs and to cooldown the reactor coolant system. The Unit 1 and Unit 2 Technical Specificati3ns required minimum volumes of 140,000 and 127,000 gallons to be maintained in the primary plant demineralized water storage tanks, respectively. The unusable inventory in the bottom of the tank is approximately 12,000 gallons for Unit 1 and 10,575 gallons for Unit 2. For both units the available condensate - i inventory was greater than the inventory required to remove the decay heat for 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> and to cooldown the reactor coolant system. The methodology used for this calculation followed the guidance provided in Section 7.2.1 of NUMARC 87-0 The team concluded that the condensate inventory was adequate to cope with an SBO event of a 4-hour duratio .2.6 Reactor Coolant Inventory Loss The station blackout rule required that a plant-specific station blackout capability evaluation be performed to demonstrate that adequate reactor coolant system (RCS) inventory would be l available to ensure that the core was cooled for an acceptable duration during a station j blackout event. The calculation of reactor coolant system inventory loss _was to include )

consideration for shrinkage, leakage from pump seals, and inventory loss from letdown or ]

other open lines dependent on ac power for isolation. The team reviewed the calculation l which demonstrated that adequate RCS inventory was available to cool the core during a station blackou In a letter to the NRC, dated March 30,1990, the licensee stated that the core would not uncover during a 4-hour station blackout, assuming a reactor coohuit inventory loss of 25 gallons per minute (gpm) per reactor coolant pump. In the NRC safety evaluation, a recommendation was made to consider additional RCS losses that resulted in a totalleak rate of 170 gpm. The NRC safety evaluation concluded that with a 170 gpm leak rate, the time

, to core uncovery was greater than the 4-hour SBO duration. Calculation 10080-DMC-0099,

"SBO - Core Uncovery Time," determined the time to core uncovery using a 170 gpm leak rate. The calculation used the Modular Accident Analysis Program (MAAP) to determine the coolant level in the reactor vessel. The calculation assumed that the leak rate decreased -

as the RCS depressurized due to the cooldown. The calculation concluded that it would take approximately 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> to uncover the core during a SBO event assuming an initial RCS leak rate of 170 gp The team verified by independent calculations that the 170 gpm leak rate assumption was conservative. A bounding calculation was also performed assuming a 170 gpm leak rate for the duration of the SBO event (no decrease in leak rate due to RCS depressurization), which also concluded that the core would remain covered during a 4-hour duration SBO event. The SBO core uncovery time calculation was detailed and technically sound. The team concluded that, based on the RCS leak rate assumptions, the core would not uncover during a SBO of 4-hour duratio _ _ _ . _ . -

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The team reviewed the emergency lighting and communication equipment to assure that adequate lighting was available to operate station blackout equipment and communications equipment was adequate to coordinate the emergency operating procedure i The existing Appendix "R" emergency lighting units are used to provide lighting during a  !

station blackout event. The lights are powered by a battery pack that has an 8-hour capacit The team performed a walkdown of selected Unit 1 and Unit 2 areas where local operation l

of SBO equipment was required to assure that the SBO equipment could be operated with the existing emergency lightin i Four independent communication systems are available to station operators during a station blackout event. The two primary communication systems are the plant paging system and the private automatic exchange (PAX) system. The two backup systems are portable radios and the calibration jack system. The Unit i paging system is powered by the class 1E uninterruptible power supply (UPS) system. The Unit 2 paging system is powered by a nonclass 1E uninterruptible power supply system. Both units paging UPS power supplies are backed up by batteries. Both battery units have sufficient capacity for a 4-hour SBO duration. The PAX system is a hard-wired dial type telephone communication system that provides a communication link to various plant areas where SBO equipment would be locally operated. Each unit's PAX system can be powered from a nonclass 1E battery, which has an 8-hour capacit The team concluded that the emergency lighting and communication equipment were adequate to operate SBO equipment and coordinate emergency operating procedure activities during a SBO even .2.8 Chemical and Volume Control

The team verified that the valves within the chemical and volume control system (CVCS)

makeup flow path from the refueling water storage tank or alternate water source could be operated independent of the preferred and blacked-out unit's normal Class 1E ac power l sourc The team reviewed the CVCS system drawings and associated plant procedures used to place a charging pump in operation during a station blackout. Emergency Operating Procedure (EOP) ECA-0.0, " Loss of All AC Power," provided direction for starting a charging pump i

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and initiating injection into the reactor coolant system. The procedure provided detailed instructions for connecting the alternate ac power source to the blacked-out unit and restoring power to the motor-operated valves required to realign the charging pump suction flow path !

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The team concluded that the procedures to operate a charging pump following the restoration of ac power were appropriat l Procedures and Training 2.3.1 Severe Weather Procedure The team reviewed the severe weather procedure to verify that the procedure provided I adequate guidance to prepare the site for ensuing severe weathe ,

i The Beaver Valley site has an extremely severe weather characteristic of 1, as defined in j

Regulatory Guide 1.155, " Station Blackout." This characteristic is indicative of a location with a small probability of having winds in excess of 125 miles per hour. These high winds are normally associated with hurricanes. Due to the low probability of hurricanes at the 1

. eaver Valley site, the station does not have a procedure to prepare the site for a hurrican B However, the site does have a procedure to prepare for tornados. Abnormal Operating Procedure 1/2.75.1, " Acts of Nature-Tornado," provided instructions for the identification ,

and elimination of potential missiles from the sit ]

The team determined that the severe weather procedure was appropriate and consistent with the guidance provided in NUMARC 87-00, j

2.3.2 Emergency Operating Procedures The team reviewed plant procedures and validated selected procedure steps by walkdowns to verify that the procedures provided adequate instructions for mitigating the consequences of a SBO event and were consistent with the licensee commitments to Regulatory Guide 1.155,

" Station Blackout," Section C.3.4 (NUMARC 87-00, Section 4.2).

Emergency Operating Procedures ECA-0.0, " Loss of All Emergency 4 kV AC Power," and ECA-0.0, " Loss of All AC Power," provided operating instructions during a station blackout condition. Supplementary instructions for specific system operations were provided in the attachments to these procedures. The team reviewed these procedures to verify that the operating procedures were technically sound and the guidelines specified in Section 4.2 of NUMARC 87-00 were addressed. The team had the following findings:

ILelqrmjon of ac Power The team resiewed Section 12 of the Duquesne Light Company (DLC) System Operations &

Telecommunications Operating Manual which provided directions for the restoration of off-site power to the Beaver Valley Power Station (BVPS). This manual directed that, in the event of a system shutdown, priority must be given to energizing the 138 kV buses at the

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a BVPS, such that, the station service power'would be available within 45 minutes. Two '

methods of restoring power were included within this section of the procedure. One method included the use of combustion turbine / generators which could be black started (started without an external ac power source) and then aligned to supply the BVP The plant operator actions necessary to restore ac power from an offsite source or an emergency diesel generator were specified in the emergency operating procedures (EOPs).

The cross-tie of the alternate ac power source from the nonblacked-out unit to the blacked-

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out unit were also addressed. The team determined that the procedures were well written -

and easy to follow. The plant equipment required to be operated by these procedures were clearly marked, easily identined, and readily accessible. The team performed a walk through of the procedure steps necessary to power the Unit 1, emergency Bus 1 AE from a Unit 2 emergency bus. The team concluded that the alternate ac source could be connected to an emergency bus on the blacked-out unit and the required loads could be started within one hour of the loss of all ac powe Shutdown Equipment Operation Following the loss of all ac power, a method of reactor decay heat removal that is independent of ac power is required. At BVPS, decay heat would initially be removed by the automatic lifting of the steam generator safety relief valves. Natural circulation of reactor coolant within the reactor coolant system would transfer the heat from the reactor core to the steam generators. To make up for the water lost through the safety relief valves, the steam turbine driven auxiliary feedwater (AFW) pump would automatically start on a decreasing steam generator water level and feed water from the primary demineralized water storage tank (PDWST) to the steam generators. The suction of the auxiliary feedwater pump is normally aligned to the PDWST and no immediate operator actions would be required to establish decay heat removal. The EOPs initially direct the operators to verify AFW pump I

operation as indicated by feed flow to the steam generators. The procedures then direct the operators to commence bleeding steam manually through the atmospheric steam dump valves (ASDVs). On Unit 1, these valves are air-operated and have a handwheel to permit manual operation. The Unit 2 ASDVs are hydraulically operated and upon the loss of ac power can be operated manually using a hand pump. The EOP contained an attachment which provided specific direction on how to perform the manual operation. The AFW pump discharge valves would initially be in the full open position and feedwater flow at its maximum. As steam generator water levels begin to increase, the procedures direct the operators to manually operate the AFW pump discharge valves as required to control steam generator level in the desired band. The team verified that the valves were accessible and could be operated manually. The team noted that the EOP directed the restoration of power to the ASDVs and AFW control valves after the alternate ac source had been connected. This would restore the remote control capability of these valves to the control roo .

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Reactor Coolant Inventory Loss To minimize the loss of reactor coolant inventory, the EOPs contained steps to isolate the letdown line in the chemical and volume control system and to ensure that the power-operated relief valves (PORVs) were closed. The procedures also contained provisions to start a charging pump on the alternate ac source to provide makeup to the reactor coolant syste Backun Water Sources The PDWST for each unit had adequate makeup water to supply the steam generators for the four-hour coping duration. The EOPs provided instructions to the operators on what alternate sources of water were available and how to transfer the water to the PDWS DC Bus Load Strioning The battery capacity calculation demonstrated that adequate battery capacity was available for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> until the battery charger would be restored from the alternate power sourc Therefore, no load stripping was specified in the procedure Lpas of Ventilation Effects The licensee had identified several actions to compensate for the loss of plant ventilation systems during a station blackout. These actions included the opening of control panel doors, the Unit 1 main steam valve room ceiling louvers, and the doors between the two control rooms. The team determined that these actions were clearly specified in the procedures and no additional specific procedural actions were necessary to ensure habitability of areas required to be accessed by the operators. The team also reviewed the potential effects of the fire protection system due to elevated temperatures in the plant and determined that the fire protection system actuation setpoints were higher than the expected temperatures during a blackout condition. Therefore, spurious actuation of fire protection systems would not be expected to occu i Area Access The team reviewed the effects of the loss of ac power on the ability of operators to access areas containing SBO equipment. The team determined that the security systems would  !

remain operable. No procedural steps were necessary to ensure acces )

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Heat Tracing The SBO procedures did not contain any specific actions to compensate for the loss of heat tracing circuits. The team did not identify any specific concerns related to the loss of heat tracing. However, it did not appear that the licensee had performed a systematic review of the effects of the loss of heat tracing. The licensee stated that a review of the efrect of heat tracing loss during a SBO would be conducte Conclusion The team concluded that the station blackout procedures were well written and the level of detail in the procedures was good. The procedures were consistent with the guidance provided in NUMARC 87-00. The use of separate attachments for specific tasks made the procedures easier to implement. Specific directions for infrequently performed operations, such as the local operation of the hydraulically-operated valves using a hand pump, were also included. The team concluded that the licensee had adequately validated the time required to perform the connection of the alternate ac power source to the blacked-out uni .3.3 Emergency Diesel Generator Reliability Program .,

The team reviewed the emergency diesel generator reliability program to verify that the ,

emergency diesel generator reliability data were being trended and that the program was consistent with the NUMARC 87-00 guidanc Administrative controls for the Beaver Valley emergency diesel generator reliability program

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were provided in Procedure 3BVTil.36.2, " Emergency Diesel Generator Reliability Trend."

The procedure monitors each start and load run of the emergency diesel generators and trends the reliability of the diesels. Failure rates were trended and trigger values were established in the acceptance criteri The team concluded that the emergency diesel generator reliability program was detailed and was consistent with the NUMARC 87-00 guidanc . Station Blackout Training The station blackout training provided to the station licensed and nonlicensed operators was reviewed. The team reviewed training material and lesson plans, training attendance records, and conducted walkdowns and interviews with plant operators who had completed the trainin .. .-

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The SBO training consisted of approximately 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> of classroom training and 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> of simulator training. The training was provided to the operators as part of the normal requalification training. The lesson plans LP-LRT-VII-112, "SBO Procedures," and l simulator lesson plan " Station Blackout Cross-Tie," provided the basis for the SBO trainin !

All licensed and nonlicensed operators, except for one nonlicensed operator who was on an extended absence, had completed the station blackout training in the second quarter of 199 During an in-plant simulation, a licensed reactor operator demonstrated the manual operation of the Unit 2 hydraulically-operated auxiliary feedwater valves and closing of the Unit 2 cross-tie breaker The lesson plans were thorough and provided the operators with the knowledge required in the event of a station blackout. The duration of training was appropriate. The training was provided to both licensed and nonlicensed plant operators. The operator interviewed was cognizant of the strategies to mitigate the consequences of a station blackout and was familiar with the procedures and the operation of SBO equipment. The team concluded that the training provided to plant operators included operator actions necessary to cope with a station blackout for a 4-hour duration and to restore long-term cooling / decay heat removal once ac power was restored. The training provided on station blackout was goo .4 Modifications The team reviewed design change package (DCP) 1698 that installed a cross-tie between the Unit 1 and 2 electrical buses. This cross-tic connection enables an available emergency diesel generator on either unit to supply ac power to safe shutdown equipment on both unit The team reviewed the following documentation to ascertain the adequacy of the design and installation:

• Design drawings

• Installation instructions

• Post-modification and vendor equipment test results

• Procurement specifications (4.16 kV switchgear and 5000 V power cables)

• Breaker protection coordination

• 10 CFR 50.59 safety evaluation

• EDG voltage drop calculations

• Cable ampacity

• EDG load capacity calculations

• Seismic qualification of conduit, raceway and Class lE equipment

• Design input and output checklists

• Quality assurance verification /

The team concluded that the design change package contained adequate design detail and was technically sound. The 10 CFR 50.59 safety evaluation provided an adequate basis to determine that an unresolved safety question was not involved with this modificatio h

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The team also reviewed the modification testing. The licensee had performed tests of individual comp nents as well as a post-modification cross-tie test to verify the integrity of the power cables and the ability to transfer power between the two units. The test was performed during the Unit I refueling outage 9. This test energized a 35 ampere load (approximately 20% of total expected SBO load), on the Unit 1 nonsafety-related Bus'1D from the Unit 2 nonsafety-related Bus 2A via the cross-tie. The Unit 2 Bus 2A was being supplied by offsite power during the test. While this test did not simulate an integrated test from a emergency diesel generater on the nonblacked-out unit to a load on the emergency bus of the blacked-out unit, overlapping individual tests were performed which demonstrated that the system would function as designed. The team also reviewed the control logic and interlocks for the breakers required to be opertted during a SBO event to assure that breaker control system interlocks or trips would not prevent breaker operation during a SBO even The team concluded that the individual tests of the system were adequate to dmonstrate the operability of the cross-tie modification. Therefore, NRC Unresolved Items 50-334/93-12-03 and 50-412/93-13-03, concerning the adequacy of the modification testing, are close .

The team also reviewed the preventive maintenance program for the SBO-associated equipment and found that the licensee had established an adequate program for SBO-related components such as the 4.16 kV breaker Based on the review of the modification documentation, modification testing, surveillance testing and a field verification of the cross-tie installation, the team concluded that the SBO modification was technically sound and that the alternate ac power source satisfied the guidelines of NUMARC 87-0 .4.1 Alternate ac Source The Beaver Valley Power Station committed to provide an alternate ac source to the SBO unit within 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> by utilizing the excess capacity of the nonblack9 out unit emergency diesel generator. The team reviewed the alternate ac power source to verify that the capacity of the emergency diesel generators was adequate to power the loss of offsite power loads of *

the nonblacked-out unit and the SBO loads of the blacked-out unit. The periodic testing of the alternate ac power source was also reviewe The team identified that the EDG load calculation (8700-DEC-177-0, Revision 0) had not appropriately considered the cable losses. In addition, the input power supply requirements for the uninterruptible power supplies (UPSs) and battery chargers were not included. The team determined that nonconservative bus and motor terminal voltages were assumed in calculating the overall voltage drop on the EDG supplying the SBO loads. The licensee corrected the above EDG load calculations, which increased the previously calculated EDG ,

load by approximately 100 kW. During a SBO event, the revised total loads on the Unit I and Unit 2 diesels were 2844.7 and 3158.92 kW, respectively. Based on the revised SBO

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load calculation, the Unit 1 and 2 diesel generator loads were still less than the 2000 hour0.0231 days <br />0.556 hours <br />0.00331 weeks <br />7.61e-4 months <br /> l EDG loading limit. The revised calculation demonstrated that the EDGs could adequately j supply the required loads, at an acceptable voltage, during an SBO event. The licensee l'

stated that the applicable documents would be formally updated once the calculation revisions were finalize The NUMARC 87-00, Appendix B, item 10, states that the alternate ac (AAC) power source shall be started and brought to operating conditions that are consistent with its function as an 1 AAC source at intervals not greater than 3 months, following manufacturer's recommendations or in accordance with plant developed procedures. Once every refueling outage, a timed start and rated load capacity test shall be performed. The team noted that the Technical Specifications required EDG surveillance testing be conducted on a monthly and 18-month cycle. During monthly testing, the Unit 1 EDGs were loaded to between 2150 and 2750 kW. The 18-month test procedure required a EDG to be loaded to between 2750-and 2850 kW. The team noted that the revised Unit 1 EDG SBO load of 2844.7 kW was greater than the minimum 18-month diesel test load requirement of 2750 kW. The licensee stated that the SBO load calculation or the 18-month surveillance test would be revised such that the Unit 1 diesel generators would be tested at a load in excess of the required SBO operating loads. The Unit 2 diesel generator 18-month surveillance test required testing the Unit 2 diesel generators at a load greater than the SBO load The team concluded that the EDGs had adequate capacity to power SBO loads. The licensee stated that the 18-month Unit I surveillance test would test the Unit 1 EDGs in excess of the required SBO operating loads. The Unit 2 diesel generators were being tested at a load which was in excess of the SBO load .0 CONCLUSIONS

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The scope of this inspection was to assess the quality of the programs, procedures, training, equipment and systems for coping with a station blackout event. The inspection was conducted by reviewing the coping duration analysis, coping systems, procedures and training, and modifications. In general, the team determined that the overall responses taken to implement the station blackout rule were excellent. This inspection includes assessments in several functional areas such as operations, engineering and training, and strengths were '

identified in each area reviewed. The team determined that appropriate actions had been implemented to satisfy the station blackout rule requirement .

The coping duration analysis that determined that the Beaver Valley Power Station was a 4-hour coping plant was technically sound. The documentation that supported this analysis was ;

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detailed and provided an adequate basis to support the overall conclusio i l

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The calculations and supporting documentation that established the availability of the station blackout systems were thorough. The calculations clearly demonstrated that the station blackout systems are adequate to cope with a station blackout of a 4-hour duratio The station blackout procedures provided detailed instructions for the operation of systems and equipment during a station blackout event. The station blackout procedures were thorough and of high quality. The station blackout training provided to licensed and nonlicer. sed plant operators was thorough and provided the operators with the information necessary to mitigate the consequences of a station blackout even i The cross-tie modification design and supporting documentation were of high quality. The post modification testing of the cross-tie was acceptabl .

The team identified some discrepancies in the SBO diesel loading calculations. The revised loading calculation indicated a SBO load on the Unit 1 emergency diesel generator of approximately 2844 kW. The team noted that this was in excess of the minimum required 18-month surveillance test load for the Unit 1 diesels. The licensee stated that' action would be taken to ensure that the diesel is periodically tested at a load equal to or greater than the -

required operating station blackout load .0 EXIT MEETING The team met with those denoted in Attachment A on September 3,1993, to discuss the preliminary inspection findings which are detailed m this inspection report. The licensee did - '

not dispute the inspection finding _. ,

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ATTACHMENT A PERSONS CONTACTED

Duauesne Licht Comoany

• P. Dearborn Supervisor Engineering

• K. Frederick Supervisor Engineering

• T. Gaydosik Sr. Nuclear Operations Instructor

• K. Grada Unit Manager - Quality Services  :

• K. Halliday Director, Electrical Engineering

• K. Lynch Nuclear Engineering Department - Electrical

• J. Maracek

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Sr. Licensing Supervisor

• D. McLain . Manager Maintenance Engineering and Assessment

• S. Nass Director Nuclear Engineering Services j

• T. Noonan General Manager Nuclear Engineering and Safety

• K. Ostrowski Operations Manager Unit 1 C. O'Neil Operations

• B. Sepelak Licensing Engineer

• J.Sieber Sr. Vice President and Chief Nuclear Officer

• H. Siegel Manager Nuclear Engineering Department

• D. Spocrry Division Vice-President Nuclear Operations ,

• D. Szucs Sr. Engineer, Licensing

• N. Tonet Manager Nuclear Safety

• R. Zabowsk, Director, System Engineering U. S. Nuclear Regulatory Commission

• J. Durr Engineering Branch Chief, DRS l

• S. Greenlee Resident Inspector - Beaver Valley Others

• J. Lortz Devonrue

• A. Marion NUMARC - Manager

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• J. Pendergast Compliance Engineer (Detroit Edison Fermi 2)

Asterisk (*) denotes those present at the exit meetin ,

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