ML20125A706

Proposed Revisions to Tech Specs to Add Leak Rate Surveillance Requirements to ECCS & Containment Sys

ML20125A706
Person / Time
Site:	Millstone
Issue date:	08/31/1979
From:	NORTHEAST UTILITIES
To:
Shared Package
ML19242D234	List: ML20125A706
References
TAC-11348, TAC-11561, TAC-12505, TAC-42846, NUDOCS 7908140724
Download: ML20125A706 (5)

Text

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o DOCKET NO. 50-336 ATTACHMENT 1 HILLSTONE NUCLEAR POWER STATION, UNIT NO. 2 PROPOSED REVISIONS TO TECHNICAL SPECIFICATIONS 4

AUGUST, 1979 7908140727*

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August 1, 1975 CONTAINMENT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued) 3.

Verifying that each spray pump operates for at least 15 minutes, 4.

Cycling each testable, automatically operated valve in each spray system flow path through at least one complete cycle.

5.

Verifying that upon a sump recirculation actuation signal, the containment sump isolation valves open and that a recirculation mode flow path via an OPERABLE shutdown cooling heat exchanger is established, and 6.

Verifying that all accessible manual valves not locked, sealed, or otherwise secured in position and all remote or automatically operated valves in each spray system flow path are positioned to take suction from the RWST on a Containment Pressure -- High-High signal.

b.

At least once per 18 months, during shutdown, by cycling each power operated valve in the spray system flow path not testable during plant operation through at least one complete cycle of full travel, At least once per 18 months by verifying a total leak rate c.

< 12 gallons per hour in conjunction with the high pressure safety injection system, reference Specification 4.5.2.c.5, for:

1.

Those parts of the system between the pump discharge and the header isolation valve including the pump seals at a discharge pressure of > 254 psig on recirculation flow, and 2.

The piping from the containment sump check valve to the pump suction with a minimum applied pressure of 22 psig measured at the pump suction.

d.

At least once per five years by performing an air or snoke flow test through each spray header and verifying each spray nozzle is unobstructed.

MILLSTONE - UNIT 2 3/4 6-13

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1 EMERGENCY CORE COOLING SYSTE}iji SURVEILLANCE REQUIREMENTS (Continued) c.

5.

Verifying a total leak rate < 12 gallons per hour for the high pressure safety injection system in conjunc-tion with the containment spray system, reference specification 4.6.2.1.c., for:

a) the parts of the system between the pump discharge and the header injection valves including the pump seals at a discharge pressure of > 1125 psig on recirculation flow, and b) the piping from the containment sump check valve to the sump suction with a minimum applied pressure of 22 psig measured at the pump suction.

r MILL 5 TONE - UNIT 2 3/4 5-Sa

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3/4.5 EMERGENCY CORE COOLING SYSTEMS (ECCS)

BASES 3/4.5.1 SAFETY IfLIECTION TANXS The OPERABILITY of each of the RCS safety injection tanks ensures that a sufficient volume of borated water will be immediately forced into the reactor core through each of the cold legs in the event the RCS pressure falls below the pressure of the safety injection tanks.

This initial surge of water into the core provides the initial cooling mechanism during large RCS pipe ruptures.

The limits on safety injection tank volume, boron concentration and pressure ensure that the assumptions used for safety injection tank l

injection in the accident analysis are met.

The limit of one hour for operation with an inoperable safety injection tank minimizes the time exposure of the plant to a LOCA event occurring concurrent with failure of an additional safety injection tank which may result in unacceptable peak cladding temperatures.

j 3/4.5.2 and 3/4.5.3 ECCS SUBSYSTEMS The OPERABILITY of two separate and independent ECCS subsystems ensures that sufficient emergency core cooling capability will be availa-ble in the event of a LOCA assuming the loss of one subsystem through any single failure consideration.

Either subsystem operating in conjunc-tion with the safety injection tanks is capable of supplying sufficient core cooling to limit the peak cladding temperatures within acceptable limits for all postulated break sizes ranging from the double ended break of the largest RCS cold leg pipe downward.

The trisodium phosphate dodecahydrate (TSP) stored in dissolving baskets located in the containment basement is provided to minimize the possibility of corrosion cracking of certain metal components during operation of the ECCS following a LOCA.

The TSP provides this protection by dissolving in the sump water and causing its final pH to be raised to

> 7.0.

The Surveillance Requirements provided to ensure OPERABILITY of each component ensures that at a minimum, the assumptions used in the accident analyses are met and that subsystem OPERABILITY is maintained.

The requirement to dissolve a representative sample of TSP in a sample of RWST water provides assurance that the stored TSP will dissolve in borated water at the postulated post-LOCA temperatures.

The ECCS leak rate surveillance requirements assure that tht. leakage rates assumed for the system outside containment during the recirculation phase will not be exceeded.

MILLST0!iE - UNIT 2 B 3/4 5-1

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O March 23,1977 CONTAINMENT SYSTEMS

_ BASES 3/4.6.2 DEPRESSURIZATION AND COOLING SYSTEMS 20 3/4.6.2.1 CONTAINMENT SPRAY SYSTEM The OPERABILITY of the containment spray system ensures that contain-ment depressurization and cooling capability will be available in the event of a LOCA. The pressure reduction and resultant lower containment leakage rate are consistent with the assumptions used in the accident analyses. The leak rate surveillance requirements assure that the leakage assumed for the system outside containment during the recirculation phase will not be sxceeded.

3/4.6.2.2 CONTAINMENT AIR RECIRCULATION SYSTEM The OPERABILITY of the containment cooling system ensures that

1) the containment air temperature will be maintained within limits during normal operation, and 2) adequate heat removal capacity is available when operated in conjunction with the containment spray syste.ns during post-LOCA conditions.

3/4.6.3 CONTAINMENT ISOLATION VALVES, The OPERABILITY of the containment isolation valves ensures that the containment atmosphere will be isolated from the outside environment in the event of a release of radioactive material to the containment atmosphere or pressurization of the containment.

Containment isolation within the time limits specified ensures that the release of radioactive material to the environment will be consistent with the assumptions used in the analyses for a LOCA.

MILLSTONE - UNIT 2 B 3/4 6-3

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