ML20198B967

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Revised TS 3.7.11 LCO Bases to Specify That AB Filtered Ventilation Exhaust Sys Is Considered Operable When Associated Two Fans,Filters,Ductwork,Valves & Dampers Are Operable
ML20198B967
Person / Time
Site: McGuire, Mcguire  Duke Energy icon.png
Issue date: 12/09/1998
From:
DUKE POWER CO.
To:
Shared Package
ML20198B950 List:
References
NUDOCS 9812210249
Download: ML20198B967 (4)


Text

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l ABFVES' et B 3.7.11 BASES APPLICABLE SAFETY ANALYSES (continued)

(e.g., a specified fraction of Reference 5 limits). The analysis of the y,

effects and consequences of a large break LOCA is presented in Reference 3. The ABFVES also actuates following a small break LOCA, in those cases where the ECCS goes into the recirculation mode of long term cooling, to clean up releases of smaller leaks, such as from valve stem packing.

Two types of system failures are considered in the accident analysis:

complete loss of function, and excessive LEAKAGE. Either type of failure may result in a lower efficiency of removal for any gaseous and particulate activity released to the ECCS pump rcoms following a LOCA.

l The ABFVES satisfies Criterion 3 of 10 CFR 50.36 (Ref. 5).

LCO The ABFVES is required to be OPERABLE with either unit in MODES 1, 2,3, or 4. Total system failure could result in the atmospheric release t

from the ECCS pump room exceeding 10 CFR 100 limits in the event of a Design Basis Accident (DBA).

ABFVES is considered OPERABLE when the individual components necessary to maintain the ECCS pump room filtration are OPERABLE in

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both units systems.

An ABFVES is considered OPERABLE when its associated:

Fans in configuration as described below are OPERABLE:

a.

Both fans OPERABLE in any one set of fans listed below:

1 A and 1B, or 2A and 2B, or 1 A and 2A, or 1B and 2B Use of any other two fan combination requires surveillance testing in that configuration prior to taking credit for that combination.

b.

HEPA filter and carbon adsorbers are not excessively restricting flow, and are capable of performing their filtration functions; and Ductwork, valves, and dampers are OPERABLE and air circulation c.

can be maintained.

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' McGuire Units 1 and 2 B 3.7.11-2 Revision No.1 l

t 9812210249 991209 l

PDR ADOCK 05000369.i p

PDR 3 l

ABFVES 1

B 3.7.11 BASES i

LCO (continued) l The ABFVES is shared between the two units. The system must be OPERABLE for each unit when that unit is in the MODE of Applicability.

Additionally, both normal and emergency power must also be OPERABLE because the system is shared. If a ABFVES component becomes inoperable, or normal or emergency power to a ABFVES component becomes inoperable, then the Required Actions of this LCO must be entered independently for each unit that is in the MODE of applicability of the LCO.

APPLICABILITY Either unit in MODES 1,2,3, and 4, the ABFVES is required to be OPERABLE consistent with the OPERABILITY requirements of the ECCS.

Both units in MODE 5 or 6, the ABFVES is not required to be OPERABLE since the ECCS is not required to be OPERABLE.

ACTIONS M

With one unit's ABFVES inoperable, action must be taken to restore OPERABLE status within 7 days. During this time, the remaining OPERABLE unit's system is adequate to perform the ABFVES function.

One unit's system of ABFVES may be made inoperable from, but not limited to, the filter assembly, fa,is, flowpath, or the ability to maintain the I

required negative 0.125 inches of water gauge (wg) for the ECCS pump rooms relative to atmospheric pressure.

The 7 day Completion Time is appropriate because the risk contribution is less than that for the ECCS (72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Completion Time), and this system is not a direct support system for the ECCS. The 7 day Completion Time is based on the low probability of a DBA occurring during this time period, and ability of the remaining unit's system to provide the required capability.

B.1 l

With both unit's ABFVE systems inoperable, action must be taken to

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restore to OPERABLE statu.s one unit's ABFVE system within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

l The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> Completion Time is based on an adequate period of time to determine the cause of the inoperability and affect repairs without the i

McGuire Units 1 and 2 B 3.7.11-3 l

Revision No.1 l

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ABFVES B 3.7.11 BASES ACTIONS (continued) need of shutting down both units. In addition, the probability of a DBA is

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low for this short period of time.

C.1 and C.2 If the ABFVES cannot be restored to OPERABLE status within the associated Completion Time, the unit must be placed in a MODE in which the LCO does not apply. To achieve this status, the unit must be placed in at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and in MODE 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times are reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging unit systems.

SLAVElLLANCE SR 3.7.11.1 REQUIREMENTS Standby systems should be checked periodically to ensure that they function properly. As the environment and normal operating conditions on this system are not severe, testing each train once a month provides an adequate check on this system. Systems without heaters need only be operated from the control room for 215 minutes with flow through the HEPA filters and charcoal adsorbers to demonstrate the function of the system. The 31 day Frequency is based on the known reliability of equipment.

SR 3.7.11.2 This SR verifies that the required ABFVES testing is performed in accordance with the Ventilation Filter Testing Program (VFTP). The ABFVES filter tests are in accordance with Reference 4. The VFTP includes testing HEPA filter performance, carbon adsorbers efficiency, minimum system flow rate, and the physical properties of the carbon (general use and following specific operations). Specific test Frequencies 3

and additional information are discussed in detail in the VFTP.

l SR 3.7.11.3 This SR verifies that ABFVES starts and operates with flow through the l

HEPA filters and charcoal adsorbers on an actual or simulated actuation l

signal. The 18 month Frequency is consistent with that specified in Regulatory Guide 1.52 (Ref. 6).

McGuire Units 1 and 2 B 3.7.11-4 Revision No.1 l

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-8 ABFVES y

B 3.7.11 i

' BASES i

SURVEILLANCE REOUIREMENTS (continued) l

SR 3.7.11.4 i

r This SR verifies the integrity of the ECCS pump room enclosure. The i

ability of the ECCS pump room to maintain a negative pressure, with respect to potentially uncontaminated adjacent areas, is periodically tested to verify proper functioning of the ABFVES. During the post accident mode of operation, the ABFVES is desi negative pressure in the ECCS pump room area,gned to maintain a s with respect to adjacent j

areas, to prevent unfiltered LEAKAGE. The ABFVES is designed to maintain a 5 -0.125 inches water gauge relative to atmospheric pressure.

This SR is required to be performed for each fan combination (1 A and 1B,2A and 2B,1 A and 2A,18 and 28) described in the LCO Bases. The Frequency of 18 months is consistent with the guidance provided in NUREG-0800, Section 6.5.1 (Ref. 7).

- An 18 month Frequency on a STAGGERED TEST BASIS is consistent with that specified in Reference 6.

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l REFERENCES 1.

UFSAR, Section 6.5.

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2.

UFSAR, Section 9.4.

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3.

UFSAR, Section 15.6.

4.

10 CFR 100.11.

5.

10 CFR 50.36, Technical Specifications, (c)(2)(ii).

6.

Regulatory Guide 1.52 (Rev. 2).

7.

NUREG-0800, Section 6.5.1, Rev. 2, July 1981.

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r McGuire Units 1 and 2 B 3.7.11-5 Revision No.1 l

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