ML20236W840

Proposed Tech Specs Bases 3/4.7.C & 3/4.7.12.C,clarifying Testing Requirements for Primary Containment Excess Flow Check Valves

ML20236W840
Person / Time
Site:	Quad Cities
Issue date:	07/31/1998
From:	COMMONWEALTH EDISON CO.
To:
Shared Package
ML20236W829	List: ML20236W840 SVP-98-252, Application for Amends to Licenses DPR-29 & DPR-30, Clarifying Testing Requirements for Primary Containment Excess Flow Check Valves Contained in TS Bases 3/4.7.D & 3/4.12.C
References
NUDOCS 9808060243
Download: ML20236W840 (3)

Text

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_s ATTACHMENT A TECHNICAL SPECIFICATION BASES PAGE B 3/4.7.2 AND BASES PAGE B 3/4.12.3 l SVP 98-252 (Page1of3) ,

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CONTAINMENT SYSTEMS B 3/4.7

, BASES leakege tests). The acceptance criteria were established during initial air lock and primary containment OPERABILITY testing. The periodic testing requirements verify that air lock leakage does not exceed the allowed fraction of the overall primary containment leakage rate. The Frequency is required by the Primary Containment Leakage Rate Testing Program. The surveillance requirements have been annotated such that un inoperable air lock door does not invalidate the previous successful performance of the overall air lock leakage test. This is considered reasonable l since either air lock door is capable of providing a fission product barrier in the event of a DBA.

Additional annotation is provided to require the results of air lock leakage tests being evaluated 4 against the acceptance criteria applicable to the surveillance requirements. This ensures that the air lock leakage is propeily accounted for in determining the combined Type B and Type C primary containment leakage.

3/4.7.D Primary Containment isolation Valves The OPERABILITY of the primary containment isolation valves ensures that the containment atmosphere will be isolated from the outside environment in the event of a release of radioactive 4 material to the containment atmosphere or pressurization of the containment. Containment isolation within the time limits specified for those isolation valves designed to close automatically ensures thet the release of radioactive material to the environment will be consistent with the j

assumptions used in the analyses for a LOCA.

The containment is also penetrated by a large number of small diameter instrument lines which contact the primary coolant system. A program for periodic testing and examination of the flow check valves in these lines is performed by blowing down the instrument line during(/ypp$ep%df t/)

cnd observing conditions which verify that the flow check valve is operable, e.g., a distinctive h

, ' click' when the poppst valve seats, or an instrumentation high flow that quickly reduces to a J slight trickle.

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b ycircsMic f e3t f The main steam line isolation valves are tested at lower pressures, per an a ed exemption, but the leakage rate is included in the Type B and C test totals. ' The surveillance testing for measuring leakage rates is consistent with the requirements of Appendix J of 10CFR Part 50 with the sxception of approved exemptions. (Ref: Exemption Request Approval, Mr. D. B. Vassallo {NRC) to Mr. D. L. Farrar (CECO) dated JJne 12,1984.)

3/4.7.E Suppression Chamber - Drywell Vacuum Breakers The function of the suppression chamber to drywell vacuum breakers is to relieve vacuum in the drywell. These internal vacuum breakers allow air and steam flow from the suppression chamber ,

to the drywell when the drywell is at a negative pressure with respect to the suppression chamber.

Each vacuum breaker is a self-sctuating valve, similar to a check valve.

The safety analysis assumes that the intemal vacuum breakers are closed initially and are fully cpen at a differential pressure of 0.5 psid. Additionally, three of these internal vacuum breakers OUAD CITIES - UNITS 1 & 2 B 3/4.7-2 Amendment Nos. 171 8 147

SPECIAL TEST EXCEPTIONS B 3/4.12 BASES l e OPERATIONAL MODE 4 applicable requirements that are in effect immediately orior to and immediately after this operation.

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T OPERATI NAL MODE 4 requirements may only be modified for the performance of inservice

_ 44% tes so that these operations can be considered as in OPERATIONAL MODE 4, even though the reactor coolant temperature is >212*F. The additional requirement for secondary containment OPERABILITY according to the imposed OPERATIONAL MODE 3 requirements provides conservatism in the response of the unit to any event that may occur. Operations in all other OPERATIONAL MODES are unaffected by this LCO.

I sk se % arosT Q Footnote (a) has been provided to modify the ACTIONS relatbJ to pressure testing operation.

Footnote (a) allows a separate condition entry for each requirement of the LCO.

If an LCO specified in LCO 3.12.C is not met, the ACTIONS applicable to the stated requirements are entered immediately. ACTION 1 has been modified by Footnote (b) that clarifies the intent of another LCO's ACTION to be in OPERATIONAL MODE 4 which includes reducing the average reactor coolant temperature to s212 *F.

ACTION 2 is an afternete action that can be taken instead of ACTION 1 to restore compliance with the normal OPERATIONAL MODE 4 requirements, and thereby exit this Special Test Exception LCO's Applicability. Activities that could further increase reactor coolarit temperature or pressure are suspended immediately, in accordance with ACTION 2, and the reactor coolant temperature is reduced to establish normal OPERATIONAL MODE 4 requirements. The allowed completion time of 24 heaurs for ACTION 2 provides sufficient time to reduce the average reactor coolant temperature from the highest expected value to s212*F with normal cooldown procedures. The completion time is also consistent with the time provided in LCO 3.0.C to reach OPERATIONAL MODE 4 from OPERATIONAL MODE 3.

The applicable LCOs are required to have their Surveillance met to establish that this LCO is being met. A discussion of the applicable Surveillance Requirements is provided in their respective Bases.

QUAD CITIES - UNITS 1 & 2 B 3/4.12-3 Amendment Nos. 179 & 177

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