ML18153D271

Proposed TS 3.16.-5 Re Control Area Air Conditioning Equipment & 3.23 Re Main Control Room & Emergency Switchgear Room Ventilation & Air Conditioning Sys

ML18153D271
Person / Time
Site:	Surry
Issue date:	03/15/1993
From:	VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
Shared Package
ML18153D270	List: ML18153D269 ML18153D271
References
NUDOCS 9303190014
Download: ML18153D271 (9)

Text

• Attachment 2 Technical Specifications Changes

-~--9303190014- 930315-- -- -- ---

PDR ADOCK 05000280 p PDR

• TS 3.16-5 The diesel generators function as an on-site back-up system to supply the emergency buses. Each emergency bus provides power to the following operating Engineered Safeguards equipment:

A. One containment spray pump B. One charging pump C. One low head safety injection pump D. One recirculation spray pump inside containment E. One recirculation spray pump outside containment F. One containment vacuum pump G. One motor-driven auxiliary steam generator feedwater pump H. One motor control center for valves, instruments, control air compressor, fuel oil pumps, etc.

I. Control area air conditioning equipment - four air recirculating units, two water chilling units, one service water pump and two chilled water circulating pumps J. One charging pump service water pump for charging pump intermediate seal coolers and lube oil coolers K. One charging pump cooling water pump for charging pump seal coolers.

Amendment Nos.

3.23

• MAIN CONTROL ROOM AND EMERGENCY SWITCHGEAR

• TS 3.23-1 ROOM VENTILATION AND AIR CONDITIONING SYSTEMS Applicability Applies to the Main Control Room (MCR) and Emergency Switchgear Room (ESGR) Air Conditioning System and Emergency Ventilation System.

Objective To specify requirements to ensure the proper function of the Main Control Room and Emergency Switchgear Room Air Conditioning System and Emergency Ventilation System.

Specification A. Both trains of the Main Control Room and Emergency Switchgear Room Emergency Ventilation System shall be OPERABLE whenever either unit is above COLD SHUTDOWN.

B. With one train of the Main Control Room and Emergency Switchgear Room Emergency Ventilation System inoperable for any reason, return the inoperable train to an OPERABLE status within 7 days or be in at least HOT SHUTDOWN within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />.

C. The Main Control Room and Emergency Switchgear Room Air Conditioning System shall be OPERABLE as delineated in the following:

• 1. Chiller Refrigeration Units

a. Three main control room and emergency switchgear room chillers must be OPERABLE whenever either unit is above COLD SHUTDOWN.

• This interim specification is necessary until the air conditioning system modifications are completed. Following completion of the permanent modifications, a revised air conditioning system specification will be submitted.

Amendments Nos

• b.

• TS 3.23-2 The three OPERABLE chillers are required to be powered from three of the four emergency buses with one of those chillers capable of being powered from the fourth emergency bus.

c. If one of the OPERABLE chillers becomes inoperable or is not powered as required by Specification 3.23.C.1.b, return an inoperable chiller to OPERABLE status within seven (7) days or bring both units to HOT SHUTDOWN within the next six (6) hours and be in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

d. If two of the OPERABLE chillers become inoperable or are not powered as required by Specification 3.23.C.1.b, return an inoperable chiller to OPERABLE status within one (1) hour or bring both units to HOT SHUTDOWN within the next six (6) hours and be in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

2. Air Handling Units (AHU)

a. Unit 1 air handling units, 1-VS-AC-1, 1-VS-AC-2, 1-VS-AC-6, and 1-VS-AC-7, must be OPERABLE whenever Unit 1 isl above COLD SHUTDOWN.

1. If one Unit 1 AHU becomes inoperable, return the in-operable AHU to OPERABLE status within seven (7) days or bring Unit 1 to HOT SHUTDOWN within the next six (6) hours and be in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

b. Unit 2 air handling units, 2-VS-AC-8, 2-VS-AC-9, 2-VS-AC-6, and 2-VS-AC-7 must be OPERABLE whenever Unit 2 isj above COLD SHUTDOWN.

1. If one Unit 2 AHU becomes inoperable, return the in-operable AHU to OPERABLE status within seven (7) days or bring Unit 2 to HOT SHUTDOWN within the next six (6) hours and be in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

Amendment Nos.

• TS 3.23-3 When the supply of compressed bottled air is depleted, the Main Control Room I and Emergency Switchgear Room Emergency Ventilation System is manually started to continue to maintain the control room pressure at the design positive pressure so that leakage is outleakage. One train of the main control room emergency ventilation consists of one fan powered from an independent emergency power source.

The Main Control Room and Emergency Switchgear Room Emergencyl Ventilation System is designed to filter the intake air to the control room pressure envelope, which consists of the control room, relay rooms, and emergency switchgear rooms during a loss of coolant accident. I High efficiency particulate air (HEPA) filters are installed before the charcoal adsorbers to prevent clo~ging of the iodine adsorbers. The charcoal adsorbers are installed to reduce the potential intake of radio-iodine to the control room.

The in-place test results should indicate a system leaktightness of less than 1 percent bypass leakage for the charcoal adsorbers and a HEPA efficiency of at least 99.5 percent removal of DOP particulates. The laboratory carbon sample test results should indicate a radioactive methyl iodide removal efficiency of at least 95 percent for expected accident conditions. The control room dose calculations assume only 90 percent iodine removal efficiency for the air passing through the charcoal filters. Therefore, if the efficiencies of the HEPA filters and charcoal adsorbers are as specified, at the temperatures, flow rates and velocities within the design values of the system, the resulting doses will be less than the allowable levels states in Criterion 19 of the General Design Criteria for Nuclear Power Plants, Appendix A to 1O CFR Part 50.

If the system is found to be inoperable, there is no immediate threat to the control room, and reactor operation may continue for a limited period of time while repairs are being made. If the system cannot be repaired within the specified time, procedures are initiated to establish conditions for which the filter system is not required.

Amendment Nos.

• The Main Control Room and Emergency Switchgear Room Air Conditioning TS 3.23-4 System cools the main control room, the control room annex and the Units 1 andf 2 emergency switchgear rooms. The existing air conditioning system includes three chillers (1-VS-E-4A, 48, and 4C) and eight air handling units (1-VS-AC-1, 2, 6, 7 and 2-VS-AC-6, 7, 8, and 9).

Interim modifications were completed on the Main Control Room and Emergency!

Switchgear Room Air Conditioning System to address interim failure and increased cooling requirements for the emergency switchgear rooms. Permanent modifications will include replacement of the main control room and emergency' switchgear room air handling units (AHU) and installation of additional chiller capacity to restore original design flexibility.

Units 1 and 2 main control room and emergency switchgear room AH Us have I been replaced in the initial phases of the permanent modification, restoring redundancy to the AHU portion of the original system design. As a result, the following main control room and emergency switchgear room equipment isl

'

required to operate to maintain design temperature under maximum heat load conditions:

• Two chillers

• • One Unit 1 MCR AHU and one Unit 1 ESGR AHU

• One Unit 2 MCR AHU and one Unit 2 ESGR AHU The existing chiller configuration requires that the three chillers in MER-3 (1-VS-E-4A, 48, and 4C) be OPERABLE so that in the event of a total Loss. of Offsite Power to the station and the single failure of an emergency bus or a chiller, two chillers remain available. Installation of the two additional chillers in MER-5 (1-VS-E-4D and 4E) will provide operational flexibility. Any three of the five installed chillers, powered from separate emergency buses with one of those capable of being powered from the fourth emergency bus, will ensure two chillers are available to maintain design temperature under maximum heat load conditions.

This operational flexibility is necessary to complete the permanent modification of the existing chillers.

In addition to the equipment restrictions above, a fire watch will be required during this interim period in MER-3 to address Appendix R considerations. I Amendment Nos.

• Attachment 3 Significant Hazards Consideration

• Significant Hazards Consideration

• Virginia Electric and Power Company has reviewed the proposed changes against the*

criteria of 1o CFR 50.92 and has concluded that the changes as proposed do not pose a significant hazards consideration. Specifically, operation of the Surry Power Station in accordance with the proposed Technical Specification changes will not:

1. Involve a significant increase in the probability of occurrence or consequences of an accident previously evaluated.

The Main Control Room and Emergency Switchgear Room Air Conditioning System is not involved in the initiation of any previously evaluated accidents.

Therefore, the probability of such accidents is not affected. The requirement to have three chillers operable whenever either unit is above Cold Shutdown is being maintained. Any three operable chillers, powered from three of the four emergency buses with one of the chillers capable of being powered from the fourth emergency bus, will continue to provide equivalent capacity and redundancy to remove the heat load during normal and accident conditions.

Providing one hour to restore a second chiller to operable status when there is only one operable chiller does not change air conditioning system or equipment operation. Therefore, the probability of occurrence and the consequence of an accident previously evaluated is not increased.

Elimination of the fire watch in the emergency switchgear rooms does not affect the probability or consequences of any previously analyzed accident. The firewatch was an interim measure pending completion of the AHU upgrade restoring air handling capacity to original design. The AHU modifications are complete and the interim firewatch is no longer necessary. Therefore, the fire watch has no impact on the probability of occurrence or consequences of an accident. The administrative changes do not impact plant operation or system design. Thus, the consequences of an accident are not being affected by this change.

2. Create the possibility of a new or different kind of accident from any accident previously evaluated.

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• requirements does not create any new or different kind of accident scenarios.

Operation of the Main Control Room and Emergency Switchgear Room Air Conditioning System does not change. Providing one hour to restore a second chiller to operable status when there is only one operable chiller does not change air conditioning system or equipment operation.

Elimination of the fire watch in the Emergency Switchgear Rooms does not create any new or different kind of accident scenario. The air handling capacity in the Main Control and Emergency Switchgear Rooms has been restored to original design capacity. Therefore, the interim firewatch is unnecessary for Appendix R ponsiderations. The administrative changes do not impact plant operation or system design. Therefore, no new or different kind of accident is being created.

3. Involve a significant reduction in a margin of safety.

The revised Technical Specification maintains the required capacity and redundancy in the Main Control Room and Emergency Switchgear Room Air Conditioning System to ensure sufficient heat removal during normal and accident conditions. Providing one hour to restore a second chiller to operable status when there is only one operable chiller does not significantly reduce the margin of safety.

The air handling capacity in the Main Control Room and Emergency Switchgear Room has been restored to original design capacity. Therefore, the interim firewatch is unnecessary for Appendix R considerations. The administrative changes do not impact plant operation or system design. Therefore, the margin of safety as defined in any Technical Specification is not reduced.

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