ML20154S572

Proposed Tech Specs Section 3.5.1,increasing AOT in Action B. to 24 Hours in Lieu of Current AOT of One Hour

ML20154S572
Person / Time
Site:	Wolf Creek
Issue date:	10/23/1998
From:	WOLF CREEK NUCLEAR OPERATING CORP.
To:
Shared Package
ML20154S569	List: ML20154S565 ML20154S572
References
NUDOCS 9810280020
Download: ML20154S572 (5)

Text

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ATTACHMENT IV P

PROPOSED TECHNICAL SPECIFICATION CHANGES J

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9810290020 981023 PDR ADOCK 05000482-P PDR

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3/4.5 EMERGENCY CORE COOLING SYSTEMS 3/4 5.1 ACCUMULATORS

' LIMITING CONDITION FOR OPERATION 3.5.1 Each Reactor Coolant System accumulator shall be OPERABLE with:

a. The isolation valve open and power removed,

b. A contained borated water volume of between 6122 and 6594 gallons,

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c. A boron concentration of between 2300 and 2500 ppm, and

d. A nitrogen cover-pressure of between 585 and 665 psig.

APPLICABILITY: MODES 1,2, and 3*.

ACTION:

a. With one accumulator inoperable due to boron concentration not within limits, either restore the boron concentration to within the above limits within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and reduce RCS pressure to less than 1000 psig within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />,

b. With one accumulator inoperable for reasons other than ACTION a.,

restore the inoperable accumulator to OPERABLE status within .1.heus 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> l or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and reduce RCS pressure to less than 1000 psig within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

SURVEILLANCE REQUIREMENTS 4.5.1.1 Each accumulator shall be demonstrated OPERABLE:

a. At least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> by:

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1) Verifying that the contained borated water volume and nitrogen cover-pressure in the tanks are within their limits, and

2) Verifying that each accumulator isolation valve is open.

' Pressurizer pressure above 1000 psig WOLF CREEK - UNIT 1 3/4 5-1 Amendment No. * *, ?? '0?,119 l

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3/4.5 EMERGENCY CORE COOLING SYSTEMS BASES

! ,3/4.5.1. ACCUMULATORS The OPERABILITY of each Reactor Coolant System (RCS) accumulator ensures that a sufficient volume of borated water will be immediately forced into the

, core through each of the cold legs in the event the RCS pressure falls below j the pressure of the accumulators. This initial surge of water into the core

! provides the initial cooling mechanism during large RCS pipe ruptures.

The limits on accumulator volume, boron concentration and pressure ensure that the assumptions used for accumulator injection in the safety analysis are l I met.

l The accumulator power operated isolation valves are considered to be

" operating bypasses"in the context of IEEE Std. 279-1971, which requires that l bypasses of a protective function be removed automatically whenever permissive

! conditions are not met, in addition, as these accumulator isolation valves l fail to meet single failure criteria, removal of power to the valves is required.  !

The allowed outage time limit for operation with one accumulator inoperable due to boron concentration not within limits reflects the fact that l no credit is taken in the accident analysis for boron concentration in the l accumulators during the LOCA blowdown phase, injection of borated water i provides the fluid medium for heat transfer from the core and prevents l excessive clad temperatures, contributing to the filling of the reactor vessel downcomer, The downcomer water elevation head provides the driving force required for the reisooding of the reactor core. Negative reactivity is initially a function of the void formation in the core. One accumuletor below l the minimum boron concentration limit will have no effect on available ECCS l

water and an insignificant effect on core suberiticality during reflood.

Boiling of ECCS water in the core during reflood concentrates boron in the l saturated liquid that remains in the core. Boron concentration during the j sump recirculation phase is dominated by the RWST boron concentration.

l The allowed outage time limit for operation with one accumulator inoperable for any reason other than boron concentration not within limits ensures that prt mpt action will be taken to return the inoperable accumulator to OPERABLE status. This allowed outage time limh has been determined j to have an insignificant effect on core damage frequency.

I Technical Specification 4.5.1.2, which required the performance of a l channel calibration of each accumulator water level and pressure channel once per 18 months, was relocated to the Updated Safety Analysis Report. This was l accomplished in accordance with the recommendations of Generic Letter 93-05 and NUREG-1366. These recommendations were based on the recognition that accumulator instrumentation operability is not directly related to the capability of the accumulators to perform their safety function.

3/4.5.2,3/4.5.3, and 3/4.5.4 ECCS SUBSYSTEMS The OPERABILITY of two independent ECCS subsystems ensures that sufficient emergency core cooling capability will be available in the event of a LOCA assuming the loss of ore subsystem through any single failure consideration.

Either subsystem operating in conjunction with the accumulators 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. In addition,

' each ECCR subsystem provides long-term core cooling capability in the recirculation mode during the accident recovery period.

With the RCS temperature below 350 F, one OPERABLE ECCS subsystem is acceptable without single failure consideration on the basis of the stable l

reactivity condition of the reactor and the limited core cooling requirements.

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WOLF CREEK - UNIT 1 B 3/4 5-1 Amendment No.119 l

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• ' Attachment V to WO 98-0082 Page 1 of 2 1

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l Attachment V List of Committ.ents j

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l Attachment V to WO 98-0082 l ,

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LIST OF COMMITMENTS l The following table identifies those actions committed to by Wolf Creek l

Nuclear Operating Corporation (WCNOC) in this document. Any other statements in this submittal are provided for information purposes and are not considered to be commitments. Please direct questions regarding i these commitments to Mr. Michael J. Angus, Manager Licensing and

! Corrective Action at Wolf Creek Generating Station, (316) 364-8831, extension 4077.

COMMITMENT Due Date/ Event  !

This proposed revision to the WCGS technical Thirty days specifications w.ill be fully implemented within following NRC 30 days of formal Nuclear Regulatory Commission issuance of the approval, requested l amendment. l l

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