Text

Proposed Tech Specs 3.4.3.1 & 3.4.3.2 Re RCS Leakage Detection Sys & Operational Leakage to Conform W/ Recommendations of Generic Ltr 88-01
	ML20126H994
Person / Time
Site:	Nine Mile Point
Issue date:	12/30/1992
From:	; NIAGARA MOHAWK POWER CORP.
To:	;
Shared Package
ML20126H982	List: ML20126H977; ML20126H988; ML20126H994;
References
	GL-88-01, GL-88-1, NUDOCS 9301060007
	Download: ML20126H994 (10)
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..( ATTAClIMENT A-

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NIA*iAR.A h10lIAWK POWER CORPORATION-LICENSE NO. NPF-69 DOCKET NO. 50-410 -

PROPOSED CIIANGE TO TIIE TECIINICAL SPECIFICATIONS Replace pages 3/4 4-12,3/4 4-13, and 3/4 4-14 with revised pages and add pages 3/4 4-12a q and 3/4 4-14a. These revised pages have been retyped in their entirety with marginal ;

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~ -9301060007 92i230-PDR ADOCK-05000410- '

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.. EEACTOR COOLANT SYSTEM 3/4.4.3 REACTOR COOLANT SYSTEM LEAKAGE LEAKAGE DETECTION SYSTEMS -

1.lMITING CONDITIONS FOR OPERATION 3.4.3.1 The following reactor coolant system leakage detection systems shall be -

OPERABLE:

a. 'The primary containment airborne particulate radioactivity monitoring' system,

b. The primary containment airborne gaseous radicactivity monitoring system,

c. The primary containment drywell floor drain tak fill rate monitoring system, and

d. Drywell equipment drain tank 011 rate monitoring system.

APPI ICABILITY: OPERATIONAL CONDITIONS 1,2, and 3.

ACTION:

a. With the primary containment airborne particulate radioactivity monitoring system or the primary containment airborne gaseous radioactivity monitoring system INOPERABLE, operation may continue for up to 30 days provided grab samples of the containment atmosphere are obtained and analyzed at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months ; otherwise, be in at least HOT SIIUTDOWN _within the next 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months ,

b. With the drywell equipment drain tank fill rate _ monitoring system inoperable, operation .

may continue for up to 30 days provided that the drywell equipment drain tank leve' fill rate is determined via alternate methods; otherwise, be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months ,

c. With the drywell Goor drain tank fill rnte monitoring system inoperable, operation may continue for up to 30 days provided that the drywell floor drain tank fill rate is determined by a manual method that calculates the differential change in drywell floor..

drain tank level over a six minute interval with allowances for drywell floor drain pump-outflow rate; otherwise, be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

d With both drywell floor drain pumps and the drywell (loor drain tank leak rate monitoring system inoperable, restore either system to OPERABLE status within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months or be in at least HOT SHUTDOWN within-12 hours and in COLD SHUTDOWN

- within the following 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

NINE MILE POINT- UNIT 2 3/4 4-12 f

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REACTOR COOLANT SYSTEM -

3/4.4.3 REACTOR COOLANT SYSTEM LEAKADE LEAR AGE DETECTION SYSTEMS 1.IMITING CONDITIONS FOR OPERATION 4.4.3.1 The reactor coolant system leakage detection systems shall be demonstrated OPERABLE by:

a. Primary containment atmosphere particulate and gaseous monitoring systems-performance of a CHANNEL CHECK at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , a SOURCE CHECK at least once per 31 days, a CHANNEL FUNCTIONAL TEST at least once per 184 days and a CHANNEL CALIBRATION at least once per 18 months,

b. Primary containment sump flow monitoring system-performance of a CHANNEL FUNCTIONAL TBST at least once per 31 days and a CHANNEL CALIBRATION TEST sc, least once per 18 months.

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- NINE MILE POINT - UNIT 2 3/4 4-12a

l REACTOR COOLANT SYSTEM REACTOR COOLANT SYSTEM LEAKAGE

- OPERATIONAL LEAKAGE LIMrriNC CONDITIONS FOR OPERATION 3.4.3.2 Reactor coolant system (RCS) leakage shall be limited to:

a. No PRESSURE BOUNDARY LEAKAGE.

b. 5 gpm UNIDENTIFIED LEAKAGE.

c. 25 gpm IDENTIFIED LEAKAGE averaged over any 24-hour period.

d. 0.5 gpm leakage per nominal inch of valve size up to a maximum 5 gpm at an RCS pressure of 1020120 psig from any reactor coolant system pressure isolation valve specified in Table 3.4.3.2-1.

c. 2 gpm increase in UNIDENTIFIED LEAKAGE within any 24-hour period in Mode 1. l -

APPLICABILITY: OPERATIONAL CONDITIONS 1,2, and 3.

ACTION:

a. With any PRESSURE BOUNDARY LEAKAGE, be in at least HOT SHUTDOWN <

within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and in COLD SHUTDOWN within the next 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

b. With any RCS leakage greater than the limits in Specification 3.4.3.2.b and/or c (above), reduce the leakage rate to within the limits within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months ,

c. With any RCS pressure isolatica valve leakage greater than the above limit, isolate the high-pressure portion of the affected system from the low-pressure portion within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months by use of at least two other closed (manual or deactivated automatic or check')

valves, or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

d. With one or more of the high/ low-pressure interface valve leakage pressure monitors ,

shown in Table 3.4.3.2-2 inoperable, restore the inoperable monitor (s) to OPERABLE status within 7 days or verify the pressure to be less than the alarm setpoint at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months ; restore the inoperable monitor (s) to OPERABLE status within 30 days or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and in COLD SHUTDOWN within the following '4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months .

'Whic5 have been verified not to exceed the allowable leakage limit at the last refueling outage.

4 NINE MILE POINT - UNIT 2 3/4 4-13

. REACTOR COOLANT SYSTEM REACTOR COOLANT SYSTEM LEAKAGE QlTRATIONAL LEAKAGE LIMITING CONDITIONS FOR OPERATION . , ,

c. With one or more of the required interlocks shown in Table 3.4.3.2-3 inoperable, restore the inoperable interlock to OPERABLE status within 7 days or isolate the _

affected heat exchanger (s) from the RCIC steam supply by closing and deenergizing heat =

exchanger valves 2 RHS*MOV22A and 2RHS*MOV80A or 2RHS*MOV22B and 2RHS*MOV808, as appropriate.

f. With any reactor coolant system leakage greater than the limit in 3.4.3.2.e above, identify the source of leakage within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

SURVEILL ANCE REOUIREMENTS ___

4.4.3.2.1 The RCS leakage shall be demonstrated to be within each of the above limits by:

a. Monitoring the primary containment airborne particulate radioactivity at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months ,

b. Monitoring the drywell floor drain tank and equipment drain tank fill rate at least once per 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months ,

c. Monitoring the primary containment airborne gaseous radioactivity at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , and

d. Monitoring the reactor vessel head flange leak detection system at least once per 24.

hours.

-4.4.3.2.2 Each RCS pressure isolation valve specified in Table 3.4.3.2-1 shall be demonstrated OPERABLE by leak testing pursuant to Specification 4.0.5 as outlined in the ASME Code Section XI, paragraph IWV-3427(b) and verifying the leakage of each valve to -

be within the spec!iled limit:

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a. At least once per 18 months, and

b. Before returning the valve to service following maintenance, repair, or replacement work on the valve.

The provisions of Specification 4.0.4 are not applicable for entry into OPERATIONAL CONDITION 3.

1 NINE MILE POINT - UNIT 2 3/4 4 '

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REACTOR COOLANT SYSTEM REACTOR COOLANT SYSTEM LEAKAGE QPERATIONAL LEAK. AGE ~

SURVEll LANCE REOUIREMENTS l'

4.4.3.2.3 The high/ low-pressure interface valve leakage pressure monitors shall be demonstrated OPERABLE with setpoints per Table 3.4.3.2-2 by performance of a:

a. CHANNEL FUNCTIONAL TEST at least once per 31 days, and

b. CHANNEL CALIBRATION at least once per 18 months.-

4.4.3.2.4 The high/ low-pressure interface interlock for the steam condensing mode bypass valve shall be demonstrated OPERABLE with trips setpoints per Table 3.4.3.2-3 by performance of:

! a. CHANNEL FUNCTIONAL TEST at least once per 92 days, and

b. CHANNEL CALIBRATION at least once per 18 months.

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NINE MILE POINT - UNIT 2 3/4 414a -

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A'ITACllMENT B NIAGARA MOIIAWK POWER CORPORATION LICENSE NO NPF-69 DOCKET NO. 50-410 SUPPOIU'ING INFORMATION AND NO SIGNIFICANT IIAZARDS CONSIDERATION Introduction The proposed changes described herein are in accordance with Section 2.1 of the NRC letter to Niagara Mohawk dated August 17, 1990. In that letter the Staff requested that a Technical Specification amendment application be submitted for Nine Mile Point Unit 2 in order to comply with Generic Letter 88-01 as modified in the August 17,1990 letter. The proposed changes: 1) impose limits on increases on unidentified leakage while h operational condition 1, 2) impose compensatory measures for inoperable fill monitoring systems, 3) decrease the surveillance interval for monitoring drywell leakage from 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months to 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months .

The proposed changes correct a discrepancy between the containment sample frequencies given in RCS operational leakage and RCS leakage detection systems.

Discussion An increase in unidentified leakage, as detected by leakage detection systems, is indicative of possible pipe cracks. These cracks can propagate over time to critical crack size and eventually result in gross pipe failure depending on the attendant mechanical and environmental conditions. Pipe failure in the Reactor Coolant System (RCS) constitutes a compromise of the integrity of a nuclear system process barrier and must be prevented.

With earlier warning of leakage, the operator has more time to initiate corrective action and cffect this prevention. Consequently, potential for gross pipe failure is detected sooner.

(Reference Generic Letter 88-01)

The proposed changes facilitate earlier detection of RCS leakats conditions. The proposed change to Technical Specification 3.4.3.2 includes an additional Limiting Candition for Operation (LCO) for increases in RCS operational leakage. Specifically, a plant shutdown shall be initiated if the RCS unidentified leakage increases by 2 gpm within any 24-hour period. The 2 gpm increment is within the accuracy of the monitoring instrumentation which an detect a change of I gpm in one hour. The action statement associated with this LCO, Actica 3.4.3.2.f, allows for a four-hour period to identify the leak as non-pressure boundary, as recommended by the Staffin their August 17,1990 letter. This LCO and accompanying action statement require operator action that decreases the probability and consequences of a pipe failure by requiring an orderly shutdown before the failure could occur.

The increase in unidentified leakage is only applicable in Mode 1, since the increase is measured relative to the steady state value. Temporary changes in leakage rate as a result of transient conditions, e.g. startups, are not considered. This is based on a surveillance requirement contained in BWR/6 new standard Technical Specifications issued as NUREG 1434 on September 28,1992.

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The proposed change to Technical Specification 4.4.3.2.1.b decreases the surveillance interval for monitoring the primary containment drywell floor drain tank and equipment drain tank fill rate to at least once per 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months . The previous monitoring requirement was at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . More frequent monitoring will increase the probability of identifying a leakage condition sooner. Therefore, the proposed changes to these Technical Specifications would enhance the margin of safety by initiating' prompt corrective action to prevent a condition that could threaten a nuclear system process barrier.-

There are three changes proposed for the action statements contained in Technical Specification 3.4.3.1. The first two additions allow for a 30 day out-of service time for the drywell floor drain tank or the drywell equipment drain tank leak rate monitoring systems provided that a manual method of determining the leak rate is employed. If after 30 days the inoperable drywell leak rate monitoring system is not restored, then an orderly shutdown will .;

be commenced. This will assure that the plant will not operate indefinitely in a condition in which the ability to detect an increase in drywell leakage has degraded.

In the proposed manual method for the drywell floor drain tank leak rate monitoring system determines the leak rate by measuring the differential change in the drywell floor drain tank over a six-minute interval with allowances for drywell floor drain pump outflow rate. All of the independent variables in the calculation are readily available to the operators. This manual method is a replacement for the calculation described in Section 5.2.5.2.1 of the Updated Safety Analysis Report (USAR). The equation referenced in the USAR is performed by the level differentiator within the drywell floor drain leakage rate monitor.

The proposed manual method is equivalent in design to the equation performed by the level l differentiator. Therefore, the leakage monitoring will continue to be accomplished by a method outlined in the USAR. The alternate method for the drywell equipment drain will be performed using a similar process.

The third change is the proposed action statement of Technical Specification 3.4.3.1 which' requires an orderly shutdown after a 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months out-of-service time if both drywell floor dmin-tank pumps and the drywell floor drain tank fill rate leakage' monitoring system are '

simultaneously inoperable. The 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months out-of-service time would not significantly decrease the ability to detect leakage because sufficient diverse and redundant means.of detecting leaks as described in Section C.3 of Regulatory Guide 1.45 are available. . The shutdown requirement assures that the plant will not operate in a degraded condition for a prolonged period when the ability to detect a drywell floor drain leak has decreased. These changes are -

consistent with the Staff's position as described in Section 2.1.(3) of the NRC letter dated August 17,1990 to Niagara Mohawk regarding Generic Letter 88-01.

This proposed change also corrects a discrepancy between.the surveillance frequency for .

containment airborne activity given in Technical Specification surveillance requirement 4.4.3.2.1.a and Action 3.4.3.1. Specification 4.4.3.2.1.a states that required frequency for monitoring of containment airborne radioactive actiNy is at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . The Action Statement of Technical Specification 3.4.3.1 states that if any containment airborne -

radioactivity monitoring system is inoperable, operation may continue for up to 30 days-provided that a grab sample is taken and analyzed at once per 24 imurs. The frequencies given in these two specifications are in conflict, since even with t 2 automatic monitoring -

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systems inoperable, the containment must still be monitored at least once every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months per :

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surveillance requirement 4.4.3.2.1.a. With the automatic systems inoperable, this would be '

done via a grab sample. Hence, the required grab sample frequency of 3.4.3.1 is being changed to at least once per 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months to be consistent with surveillance requirement -4.4.3.2,l.a.

Conclusion Nine Mile Point Unit 2 can be safely operated with the proposed changh since the new requirements will permit more rapid detection of RCS leaks and corrective actions will be initiated sooner than the current requirements. The proposed changes will not create the possibility of a new or different kind of accident from any accident previously evaluated.

Since the failure of a leakage monitoring system is not an initiating event for any Nine Mile-Point Unit 2 accident analyses, the use of a manual method when the electronically '

determined Icakage is unavailable does not increase the probability of an accident. The 24-hour out-of-service time will not significantly prevent drywell floor drain leakage detection since other diverse and redundant leak detection methods are available.

The proposed changes do not introduce any new operational modes or physical modifications to the plant. Also, the proposed changes allow a more rapid detection of throughwall cracks in the Reactor Coolant System and adds a new method of leak detection.

NO SIGNIFICANT II AZARDS CONSIDF. RATION Nine Mile Point Unit 2 can be safely operated with the incorporation of the changes in the proposed amendment. 10CFR50.91 requires that at the time a licensee requests an amendment, it must provide the Commission its analysis using the standards in 10CFR50.92 concerning the issue of no significant hazards consideration, Therefore, in accordance with 10CFR50.91, the following analysis has been performed:

The operation of Nine Mile Point Unit 2, in accordance with the proposed amendment, will not involve a significant increase in the probability or consequences of an accident previously evaluated.

The proposed changes.will not involve a significant increase in the probability or consequences of an accident previously evaluated. The proposed operational limits and surveillance requirements for reactor coolant system leakage are more restrictive than the current leak detection Technical Specification requirements and will facilitate more rapid detection of leaks. Consequently, corrective action can be initiated before crack. propagation -

is such that critical crack size is reached and a gross pipe failure occurs. Therefore, the probability of early identification of potential gross pipe failure is increased.

A failure of a leakage monitoring system is not an initiating event for any Nine' Mile Point -

Unit 2 accident analyses. The proposed change to the leakage monitoring instrumentation allows for temporary replacement of the drywell floor drain tank fill rate instrumentation and n the drywell equipment drain fill rate instrumentation with a manual method that is functionally equivalent to the electronically determined leak rate as described in the Nine-

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-Mile Point 2 USAR. The function of the leak rate monitor will be performed by control room operators. If the leak rate monitoring system and the drywell floor drain pumps are simultaneously inoperable for 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , a normal shutdown is required. The 24-hour out-of-service time will not significantly impair reactor coolant system leak detection since other diverse and redundant leak detection methods as described in Regulatory Guide 1.45 will be available to detect leakage. Since there is no decrease in the ability to detect leaks in the drywell, there is no inercase in the probability of or in the consequences of an accident previously evaluated.

The operation of Nine Mlle Point Unit 2, in accordance with the proposed amendment, will not create the possibility of a new or different kind of accident from any previously evaluated.

The proposed changes place new restrictions on operation of the plant with new limits for increases in unidentified leakage and decrease the surveillance interval for monitoring of containment leakage. Thi, will enhance the plant's ability to detect throughwall cracks of the Reactor Coolant System and to take corrective actions taken sooner. There will be no -

physical changes to the plant as a result of this amendment. Since the proposed changes will only increase the ability to detect a throughwall crack in the Reactor Coolant System, no new or different accidents are created by this amendment.

The operation of Nine Mlle Point Unit 2, in accordance with the proposed amendment, will not involve a significant reduction in margin of safety.

- The proposed changes will not involve a significant reduction in the margin of safety for Nine Mile Point Unit 2. The proposed changes provide earlier detection of throughwall cracks in the Rea'; tor Coolant System and they improve the current leak ~ detection methods for Nine-Mile Point Unit 2. The more restrictive Limiting Condition for Operation (LCO) for unidentified leakage and the more frequent surveillance requirements for Reactor Coolant .

System leakage monitoring will enhance detection of cracks such that the probability of reaching critical crack size is not increased. The 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months out-of-service time would not significantly decrease the ability to detect leakage because sufficient diverse and redundant means of detecting leaks as described in Section C.3 of Regulatory Guide 1.45 are available.

Based on the above, the proposed changes will not result in a significant reduction in a margin of safety for Nine Mile Point Unit 2.

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ML20126H994

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