ML18044A854

Responds to IE Bulletin 80-05, Vacuum Condition Resulting in Damage to Chemical Vol Control Sys (CVCS) Holdup Tanks. Four Tanks Identified That Can Have Primary Coolant Valved to Them.Plant Design Satisfactory.No Addl Action Required

ML18044A854
Person / Time
Site:	Palisades
Issue date:	05/09/1980
From:	Hoffman D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
IEB-80-05, IEB-80-5, NUDOCS 8005130367
Download: ML18044A854 (3)

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company General Offices: 212 West Michigan Avenue, Jackson, Michigan 49201

• Area Code 517 788-0550

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May 9, 1980 Mr James G Keppler Office of Inspection and* Enforcement Region III US Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137 DOCKET 50-255 - LICENSE DPR PALISADES PLANT - RESPONSE TO IE BULLETIN 80 VACUUM CONDITIONS RESULTING IN DAMAGE TO CHEMICAL VOLUME CONTROL SYSTEM (CVCS) HOLDUP TANKS Consumers Power Company's response to IE Bulletin 80-05, vacuum conditions resulting in damage to chemical volume control system (CVCS) holdup tanks (dated 3/10/80) is as follows:

Item 1

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of, Review the design of all systems that contain low pressure or holdup tanks that can be valved to contain primary system water. Assure that adequate measures have been taken to protect against vacuum conditions that could result in tank damage with the potential for release of radioactive material

• or detrimental effects with regard to overall safety of plant operations.

Item 2 Provide a listing of those systems reviewed in Item 1. Describe any measures that already exist for those systems to protect against vacuum conditions, and either; 1) explain why those measures are adequate in light of the events referenced above, or 2) identify corrective actions taken or planned to provide acceptable protection, and provide a schedule for any planned corrective actions.

Response

A review was performed of the primary coolant system, chemical and volume control system, engineered safeguards system and liquid and gaseous radioactive waste processing systems, Four tanks or tank types that can have

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primary coolant valved to them were identified. Each tank type is discussed individually below:

• clean Waste Receiver Tanks (T-64A, B, C, D)

The clean waste receiver tanks are protected from both overpressure and vacuum conditions. A relief valve is installed to prevent tank overpressurization.

A rupture disc is installed on each tank to rupture inward in the event that internal tank pressure is 2 psig below the external pressure to prevent tank collapse. These set pressures are consistent with the tank design values for pressure and vacuum.

These tanks are located inside containment. Therefore, in the unlikely event of a tank failure, any radioactive releases would be contained. Water releases to containment which could result have been taken into account in determining maximum containment water _.level following a LOCA.

Volume Control Tank (T-54)

The volume control tank is protected from overpressure by a relief valve.

Although no protection is provided for vacuum conditions, the tank is designed for full vacuum and is not expected to fail under these conditions.

The charging pumps which draw from this tank will trip off at suction pressures of 9 to 10 psia. The minimum volume control tank pressure to be expected is approximately 9 psia which is within the design capability of the tank.

Primary System Drain Tank (T-74)

This is a small tank provided to collect water from the manual PCS loop drains, other manual drains, and the shutdown cooling system relief valve.

This tank normally receives primary coolant during cold shutdown, and is pumped periodically with a small centrifugal pump. Overpressure protection is provided by a relief valve. Since hot primary coolant will not be present and the limited ability of a centrifugal pump to draw a significant vacuum, it is

• unlikely that a damaging vacuum could be created in this tank.

This tank does not have a safety function and is located inside containment.

Therefore, a tank failure would not be of reactor or radiological safety significance.

Vacuum Degasifier Tank (T-57)

The vacuum degasifier tank is protected from an overpressure condition by a relief valve. The tank normally operates at a vacuum, and is designed for a full 30 "Hg vacuum. Tank failure is not expected under these conditions.

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• 3 Conclusion From the above discussions, it is concluded that the Palisades Plant tanks which can receive primary coolant do not present an off-site release hazard.

The tank designs, locations and/or protective devices already installed preclude the type of problem experienced by Turkey Point and others. It is, therefore, concluded that present plant design is satisfactory and that no additional action is required.

David P Hoffman (Signed)

David P Hoffman Nuclear Licensing Administrator CC Director, Office of Nuclear Reactor Regulation Director, Office of Inspection and Enforcement NRC Resident Inspector-Palisades

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