L-98-109, Forwards Response to NRC 980304 RAI Re USI A-46 for Unit 1. Schedule for Completion of Future Actions Described in Encl Is by Completion of Unit 1 13th Refueling Outage,As Indicated in Util to NRC

Forwards Response to NRC 980304 RAI Re USI A-46 for Unit 1. Schedule for Completion of Future Actions Described in Encl Is by Completion of Unit 1 13th Refueling Outage,As Indicated in Util to NRC

ML20248K242
Person / Time
Site:	Beaver Valley
Issue date:	06/02/1998
From:	Jain S DUQUESNE LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
REF-GTECI-A-46, REF-GTECI-SC, TASK-A-46, TASK-OR L-98-109, TAC-M69428, NUDOCS 9806100047
Download: ML20248K242 (6)

Text

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l g m Valley Power Station l S%pphyport, PA 15077 0004 j

SUSHIL C. JAIN (412) 393-5512 Senior Vice President Fax (724) 643-806J Nuclear Servtes Nuclear Power Division June 2, 1998 l L-98-109 ]

U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001

Subject:

Beaver Valley Power Station, Unit No.1 and No. 2 j BV-1 Docket No. 50-334, License No. DPR-66 j

.BV-2 Docket No. 50-412, License No. NPF-73 Response to NRC Request for Additional Information Regarding Unresolved Safety Issue A-46 (TAC No. M69428) i Attached is the response to the NRC Request for Additional Information dated j March 4,1998, which concerned Unresolved Safety Issue A-46 for Beaver Valley, Unit 1.

The schedule for completion of the future actions described in this submittal is by the completion of the Beaver Valley Unit 1 Thirteenth Refueling Outage (IR13). This  !

schedule is consistent with the schedule provided in the Summary Report for Resolution I of USl A-46 submitted to the NRC by Duquesne Light letter dated January 31,1996. l

/

If there are any questions concerning this response, please contact Mr. S. H. Hobbs I

at (412) 393-5203.  ;

Sincerely, j / 4

/l lb ,

d- _

_,av.2 Sushil C. Jain

[ c: Mr. D. M. Kern, Sr. Resident Inspector L Mr. H. J. Miller, NRC Region I Administrator Mr. D. S. Brinkman, Sr. Project Manager '

DEllVERING 0,U 4 L i L1 l

- E N f'R O 9906100047 990602 PDR ADOCK 05000334' l P PDR l

, *d DUQUESNE LIGHT COMPANY Nuclear Power Division Beaver Valley Power Station Unit 1 e .

Attachment Response to Request for Additional Information Regarding Operator Actions Specified in Unresolved Safety Issue (USI) A-46 for Beaver Valley Power Station Unit No.1, NRC Letter Dated March 4,1998 i NRC RAI Question - Local Operator Actions Describe what reviews were performed to determine if any local operator actions required to safely shut down the reactor (i.e., implement the SSEL [ safe shutdown equipment list]) could be affected by potentially adverse environmental conditions (such as loss oflighting, excessive heat or humidity, or in-plant barriers) resulting from the seismic event. Describe how staffing was evaluated and describe the reviews that were conducted to ensure operators had adequate time and resources to respond to such events.

Response

.' As described in Generic Implementation Procedure, Revision 2 (GIP-2), Part II, Section 3.2.5, the only potential events which must be considered in the USI A-46 program are a safe shutdown earthquake (SSE) and loss of offsite power (LOOP). The plant operating procedures used to shut down the reactor following a LOOP have previously len validated for local operator actions as one of the UFSAR Chapter 14 accident scenarios. This includes potentially adverse environmental conditions such as loss oflighting and excessive heat and humidity. Note that the USI A-46 accident scenario (SSE + LOOP) explicitly excludes loss of coolant accidents (LOCA) and high energy line breaks (HELB). Therefore, the heat and humidity conditions in the plant are postulated to be equivalent to those in a UFSAR Chapter 14 LOOP scenario.

The potential for failure of plant structures and equipment is not considered credible at eastern U. S. Earthquake levels. Earthquake experience has shown that typict.1 industrial structures are l able to withstand earthquakes larger than the SSEs for eastern U.S. nuclear plants without collapse or failure. The potential for local failure of architectural features (such as suspended ceilings in the control room) and the potential for adverse seismic spatial interactions in the vicinity of safe shutdown equipment, where local operator actions may be required, was explicitly evaluated as required in GIP-2, Part II, Section 4.5 and Appendix D. For example, this review included a check that the masonry walls near safe shutdown equipment are j seismically adequate based on the results of the IE Bulletin 80-11 program. j The systems _ and equipment selected for seismic review in the USI A-45 program are those for which Normal, Abnormal, and Emergency Operating Procedures are available to bring the plant from a normal operating mode to a hot shutdown condition. As required by GIP-2, Part II,

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Sections 3.2.8 and 3.7, the safe shutdown equipment list (SSEL) was reviewed by the plant Operations Department to confirm that it is compatible with these plant procedures. Since these j l

plant procedures had already been validated to ensure that adequate time and resources are available for operators to respond to a LOOP incident, it was not necessary to re-validate these i ' procedures for the USI A-46 program.

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Attachment Page 2 The only additional operator actions, beyond those associated with the LOOP accident scenario, which must be performed to bring the plant from a normal operating mode to a hot shutdown condition are those specifically associated with the vibratory motion of the SSE. The results of the review of these operator actions with respect to whether there is adequate time and resources to respond to the postulated events are summarized below.

1.1) Seven (7) air-operated valves (AOV) at four (4) locations in the plant, were identified in the BVPS USI A-46 Summary Report of January 1996, as requiring manual operation due to the potential for loss of normal air supply. The path to each (see item 1.2) was considered, as was the required operator availability, and instructions existing in the operating procedures. The path was considered available as described above, and the effort was considered doable in terms of operators required. The procedures also provided sufficient guidance. However, it is our intention to make the procedural guidance more explicit regarding the potential for manual action being required if air supply is lost. This action will be completed prior to the end of the Beaver Valley Unit 1 Thirteenth Refueling Outage (IR13).

1.2) As a consequence of evaluating seismic-induced fire protection actuation, some systems were upgraded to prevent inadvertent operation (EDG and Main Charcoal Filter Banks),

while others' inadvertent operation was considered to be benign. The latter, such as CO2 discharge in a cable spreading room, will not adversely affect equipment, but could affect operator action. For the manual AOV operation discussed in item 1.1 above, a path around such potential obstacles was confirmed from the Control Room to each valve's area. Passage through an area such as the Turbine Building operating deck could conceivably be complicated by seismically-induced debris, but the deck offers such a large area and so many alternate routes, that an impassable condition is not considered credible.

2. NRC RAI Question - Seismic Interaction in Control Room As part of the licensee's review, were any control room stru2ures that could impact the operator's ability to respond to the seismic event identified? Such items might include but are not limited to: MCR (main control room) ceiling tiles, non-bolted cabinets, and non-restrained pieces of equipment (i.e., computer keyboards, monitors, stands, printers, etc.). Describe how each of these potential sources ofinteractions has been evaluated and describe the schedule for implementation of the final resolutions.

Response

The issue ofinteraction between Control Room (CR) equipment or furniture and operators, had been considered previous to the SQUG review. Consequently, numerous file cabinets, coat racks, and loose objects had been removed. Additionally, as part of a human factors upgrade, copiers were moved to less congested areas and seismically restrained.

The Control Room structures and components were again evaluated as part of BVPS Unit l's A-46 review. The method used for evaluating these potential sources of seismic spatial

Attachment

! .Page 3 interaction is described in GIP-2, Part II, Section 4.5 and Appendix D. The SQUG review identified the need to positively connect the ceiling panels to one another and to their support grid, (which is considered to be adequately supported), to preclude their falling onto operators and equipment. This work has been completed for both BVPS Unit 1 (A-46 plant) and Unit 2 (non-A-46). The concern over the several CR desktop personal computers and monitors sliding i and/or falling, was judged by the Seismic Capability Engineers (SCE), as not to present a significant risk to the operators. This equipment would not directly interact with Safe Shutdown Equipment List (SSEL) components.

3. NRC RAI Question - Local Operator Actions on Bad Actor Relays Describe what reviews were performed to determine if any local operator actions were required to reposition " bad actor relays." For any such activities describe how adverse environmental conditions (such as loss oflighting, excessive heat or humidity, or in-plant barriers) resulting from the seismic event were analyzed and dispositioned. Describe how staffing was evaluated and describe the reviews that were conducted to ensure operators had adequate time and resources to respond to such events.

Response

Operator actions are not required for BVPS-1 SQUG essential " bad actor" (EPRI NP-7148, Appendix E, " low mggedness") relays to reset or restore systems for bringing the plant to a hot shutdown condition. The BVPS-1 bad actor relays either had sufficient Generic Equipment Response Spectra (GERS) capacity as configured for essential function (Westinghouse SG and

~

COM-5), or their chatter effect could be tolerated (GE HGA). Stock HGA replacement relays

' have also been successfully tested (IEEE 344-75) to BVPS demand levels.

However, a number of essential relays that are not bad actor types, were reported in the BVPS January 1996, USI A-46 Summary Report, as having passed the original BVPS Unit I license basis, IEEE 344-71 testing, but for which no SQUG GERS exists. These relays cannot be

- evaluated using current SQUG criteria and, therefore, were classified as outliers in the USI A-46 Summary Report. To address their outlier status, however, we intend to evaluate their existing testing for acceptance without further qualification required (since it meets our license basis),

convert the existing testing to an IEEE 344-75 form if possible, test a representative of each relay, or replace them. Since many of the relays are in the same circuit, an additional option would be to evaluate operator action, particularly if the relays do not all seal-in, but cather cause a single component to change state, which would then need to be reset. This assessment is not yet complete, but if operator action is taken credit for, the specific operator actions to reset / restore these relays will be strictly reviewed against the conditions contained in EPRI NP-7148, Section 3.5.2. These criteria require that there be sufficient time, indication, access, and procedures available to reset or restore the systems controlled by these relays and that'these actions can be carried out by the operators and their aasistants along with their other duties. As described in' response to RAI Question 1 above, adverse environmental conditions will be considered in the review of these operator actions. Finally, any such resolution will be fully described in our USI A-46 completion letter.

' Attachment Page 4

4. NRC RAI Question - Skill of the Craft in Resetting Relays Describe which of the operator actions associated with resetting SSEL equipment affected by postulated relay chatter are considered to be routine and consistent with the skill of the craft. If not considered skill of the craft, what training and operational aids were developed to ensure the operators will perform the actions required to reset affected equipment?

. Response Resetting of relays which may have tripped as a result of a safe shutdown earthquake is not expected to be necessary as noted above, but would be consistent with the basic training received by our operators. Resetting relays i: an activity which is included within the scope of expected operator actions contained in our Normal, Abnormal, and Emergency Operating Procedures.

5. NRC RAI Question - Ope ator Response to Spurious Alarms )

I Assume the alarms associated with " bad actor relays" are expected to annunciate during the l seismic event. Do the operators have to respond to those annunciators and review the i annunciator response procedures associated with them for potential action? How would those additional actions impact' the operator's ability to implement the Normal, Abnormal, and j Emergency Operating Procedures required to place the reactor in a safe shutdown condition? 1 Response 4

)

- As described in EPRI Report NP-7148, Section 3.5.3, following an earthquake which causes the turbine to trip and the reactor to scram (Note: BVPS Unit I does not automatically trip due to monitored seismic motion),50 to 100 or more alarms are expected to annunciate. In addition to this large number of alarms, there may be several earthquake-induced, spurious clarms resulting from such events as water sloshing in tanks, oil sloshing in transformers, actuation of vibration protective instrumentation on rotating equipment, and contact chatter of relays. When the avalanche of alarms occurs, the operator will clearly be aware that the plant has tripped. ' Plant ,

procedures and operator training require that operators respond to the turbine trip and reactor i scram by confirming the scram and trip and checking important levels, temperatures, pressures, flows, and electrical switching resulting from associated power transfers. These confirmatory checks will take more than a minute to go through during which time the operators will be busy makmg these checks and not responding to specific alarms. The earthquake motion is assumed _,

to last less than a minute and the causes of the spurious alarms will have gone away during this I period while the operators are responding to the plant trip.

E The NRC staff and SQUG representatives discussed this topic in detail, including discussions held at a meeting on August 3,1988. The results of that evaluation and review are summarized in EPRI NP-7148, Section 3.5.3 where the following conclusion is reached.

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Attachment Page 5 "Accordingly, there appear to be no reasonable bases or evidence which would suggest that ,

spurious alarms resulting from an earthquake may lead to abnormal operator responses.

Therefore, special operating procedures or relay evaluation actions to address potential spurious alarms are not considered warranted and relays affecting alanns need not be seismically adequate." EPRI NP-7148, page 3-12 l

The NRC staff accepted the relay functionality review procedure summarized in GIP-2 and described in detail in EPRI NP-7148 (including the above conclusion) in Supplemental Safety Evaluation Report No. 2 on GIP-2. Therefore, we do not consider it necessary to perform any 1 additional reviews of the effect spurious alarms caused by relays (including " bad actor / low

, ruggedness" types) or other causes as a result of a seismic event.

6. NRC RAI Question - Training for Changes to Operating Procedures To the extent that Normal, Abnormal and Emergency Operating Procedures were modified to provide plant staff with additional guidance on mitigating the A-46 Seismic Event, describe what training was required and provided to the licensed operators, non-licensed operators, and other plant staff required to respond to such events.

Responsi Only one procedure (EOP) change was required as a result of the SQUG review. Normal operator training incorporates such changes. However, we have initiated another review of the procedures involved to assure ourselves that proper and sufficiently detailed operator guidance exists to implement the shutdown using SQUG-qualified equipment.

The ' initial equipment selection was operationally confirmed by a simulator exercise.

Consideration of a simulator training exercise for operators based solely upon SQUG-qualified equipment and plant conditions has been ongoing. It was earlier concluded that the operator responses to plant conditions occurring in the SQUG scenario, already exist in various simulator exercises. However, a new operator training exercise, or modification of existing exercises, to emphasize the unusual aspects of a post-earthquake shutdown, is now being considered.

Any further changes made in procedures or training will be identified to the NRC in the completion letter issued to finalize the USI A-46 effort.-