ML18153C932

Proposed TS Section 3.23 Re Main CR & Emergency Switchgear Room Air Handling Units

ML18153C932
Person / Time
Site:	Surry
Issue date:	03/09/1992
From:	VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
Shared Package
ML18153C931	List: ML18153C930 ML18153C932
References
NUDOCS 9203170210
Download: ML18153C932 (6)

Text

• ATTACHMENT 1 SURRY POWER STATION PROPOSED TECHNICAL SPECIFICATION CHANGE MAIN CONTROL ROOM AND EMERGENCY SWITCHGEAR ROOM AIR HANDLING UNITS

,.--9203170210 9 2 0 3 ~ - - ~

, PDR ADOCK 05000280 1 p PDR

3.23 MAIN CONTROL ROOM AND EMERGENCY SWITCHGEAR ROOM VENTILATION TS 3.23-1 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 and emergency switchgear room air conditioning system and emergency ventilation system.

Specification A. Both trains of the main control and emergency switchgear rooms' emergency ventilation system shall be operable whenever either unit is above cold shutdown.

B. With one train of the main control and emergency switchgear room emergency ventilation system inoperable for any reason, return the inoperable train to a 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 and emergency switchgear room air conditioning system shall be operable as delineated in the following:

• 1. Chiller Refrigeration Units

a. Chillers 1-VS-E-4A, 48, and 4C 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

• TS 3.23-2

b. If one chiller becomes inoperable, return the 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 />.

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 is above Cold Shutdown.

1. If one* Unit 1 AHU becomes inoperable, return the in- II 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 is 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 />.

• The MCR and ESGR Air Conditioning System upgrade project includes the installation of two additional chillers. It is necessary to remove each train of chilled water from service for seven days to complete the installation of the chilled water connections for the additional chillers. The modifications will require planned entries into Action Statement 3.23.C.2 with ~ inoperable AHU in the MCR and Qil.e. inoperable AHU in the ESGR of each unit to complete. These modified action statement will only be used for the installation of the chilled water connections in the MRC and ESGR Air Conditioning System and will expire June 30, 1992.

Amendments

• TS 3.23-3 When the supply of compressed bottled air is depleted, the main control room 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 and emergency switchgear room emergency 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 LOCA.

High efficiency particulate air (HEPA) filters are installed before the charcoal adsorbers to prevent clogging 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 stated in Criterion 19 of the General Design Criteria for Nuclear Power Plants, Appendix A to 10 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.

Amendments

• TS 3.23-4 The Main Control Room (MCR) and Emergency Switchgear Room (ESGR) Air Conditioning System cools the control room, the control room annex and the Units 1 and 2 emergency switchgear rooms. The 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 MCR and ESGR Air Conditioning System to address interim failure and increased cooling requirements for the ESGRs. Permanent modifications will include replacement of the MCR and ESGR AHUs and installation of additional chiller capacity to restore original design flexibility.

Units 1 and 2 MCR and ESGR AHUs have 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 MCR and ESGR equipment is 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 In addition to the equipment restrictions above, a fire watch will be required during this interim period in both unit's ESGR and MER #3 to address Appendix R considerations.

Amendments

• TS 3.23-5 Page 3.23-5 is blank Delete page 3.23-5 from the TS