ML20115J433

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Proposed TS 4.2.5 (3) Re Sum of Injection Flow Rates for RHR Pump Lines
ML20115J433
Person / Time
Site: Seabrook NextEra Energy icon.png
Issue date: 10/22/1992
From:
NORTH ATLANTIC ENERGY SERVICE CORP. (NAESCO)
To:
Shared Package
ML20115J421 List:
References
NUDOCS 9210280181
Download: ML20115J433 (8)
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-- I h,' - Markun of Pronosed Chance See attached l markup of propo ed changes to Technical' Specifications.

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EMERGENCY CORE COOLING SYSTEMS

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ECCS SUBSYSTEMS - T, GREATER THAN OR EQUAL TO 350*F SURVEltLANCE REQUIREMENTS l

4.5.2 (Cortinued)

g. By verifying the correct position of each electrical and/or mechanical- '

position stop for the following ECCS throttle valves:

1) Within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> following completion of each valve stroking operation or maintenance on the valve when the ECCS subsystems are required to be OPERABLE, and
2) At least once per 18 months.

High Head SI System Intermediate Head SI System Valve Number Valve Number SI-V-143 SI-V-80 SI-V-147 SI-V-85 SI-V-151 SI-V-104 L

SI-V-155 SI-V-109 SI-V-117 SI-V-121 SI-V-125 SI-V-129'

h. By performing a flow balance test, curing shutdown, following com-pletion of modifications to the ECCS subsystems that alter the subsystem flow characteristics and verifying that:
1) For centrifugal charging pump lines, with a single pump running:

a)_ The sum of the injection line flow rates, excluding the highest flow rate, is greater than or equal to 337 gpm, and b) The total pump flow rate is less than or equal to 550 gpm.

2) For Safety Injection pump lines, with a single pump running:

a) The sum of the injection line flow rates, excluding the highest flow rate, is greater than or equal to 445 gpm, and b) The total pump flow rate is less than or equal to 660 gpm.

3) For RHR pump lines, with a single pump running, the sum of the injection line flow rates is greater than or equal to M g %

3967 /

SEABROOK - UNIT 1 3/4 5-7 .

III,. Retvoc of Proposed Chance See attached retype of proposed changes to-Technical Specifications,- _ The attached A:

retype reflects the -currently issued version of Technical Specifications. Pending -

Technical Specific'ation changes or.'Iechnical Specification changesisisued subsequent to-this submittal'are not reflected in _the enclosed retype. The enclosed retype should' be checked for continuityLwith Technical Specifications prior to issuance, Revision bars are provided in the right hand margin to designate a change in the text.:

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r ECCS SUBSYSTEMS - T., GREATER THAN OR E0 VAL TO 350*F SURVElllANCE REOUIREMENTS 4.5.2 (Continued)

g. By verifying the correct position of each electrical and/or mechanical position stop for the following ECCS throttle valves:
1) Within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> following completion of each valve stroking operation or maintenance on the valve when the ECCS subsystems are required to be OPERABLE, and
2) At least once per 18 months.

Hiah Head 51 System Intermediate Head S1 System Valve Number Valve Number SI-V-143 SI-V-80 SI-V-147 SI-V-85 Si-V-151 SI-V-104 3 SI-V-155 SI-V-103 SI-V-117

.) SI-V-121 SI-V-125 SI-V-129

h. By performing a flow balance test, during shutdown, following completion of modifications to the ECCS subsystems that alter the subsystem flow characteristics and verifying that:
1) For centrifugal charging pump lines, with a single pump running: _

a) The sum of the injection line flow rates, excluoing the highest #10w rate, is greater than or equal to 337 gpm, and b) The total pump flow rate is less than or equal to 550 gpm.

2) For Safety Injection pump lines, with a single pump running:

a) The sum of the injection line flow rates, excluding the highest flow rate, is greater than or equal to 445 gpm, and b) The total pump flow rate is less than or equal to 660 gpm.

3) For RHR pump lines, with a single pump running, the sum of the injection line flow rates is greater than or equal to 3869 l gpm.

SEABROOK - UNIT 1 3/4 5-7 Arnendment No.

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4 ivc Safety Evaluation of I.icense Amendment Reouest 9212 Proonsed Chance

  • During a routine review of the Station procedure for cold shutdown testing of the Residual llent Removal (RilR) System North Atlantie dircovered that the acceptance value specified in the procedure for the' sum of_ the injection line flow rates with~ a single pump- running differed from the value specified in T-chnical Specification Surveillt. ace Requirement 4.5.2h.3- At North _ Atlantic's request Westinghouse reviewed the. value in Surveillance Requirement 4.5.2h.3 and determined that the current value:

of 2828 gpm is the appropriate value for flow through three of the four RHR injection lines, and that the correct value for flow through all four of the injection lines-is 3868.4 gpm.

The proposed . Technical Specification change _ is consistent with the design basis Emergency Core Cooling System (ECCS) analysis performed by Westinghouse. The Seabrook ECCS analysis is based on the calculated flow rate down three of the four Ri!R injection lines. The fourth line is assumed to spill to containment. Thus, the flow rate in three lines must be sufficient to deliver the required value of RilR flow-to the core. The calculated value of flow to the core used in this analysis is 2828.4 gpm. The calculated value used in the analysis for the total flow delivered to the core down four injection lines is 3868.4 - gpm. The ECCS analysis performed by Westinghouse for North Atlantic is available for review at WestinF ouse.h The purpose of Technical Specification 3/4.5.2 Surveillance Requirements is to casure that each of the ECCS components meets the assumptions used in the safety analysis.

In the case of Technical Specification Surveillance Requirernent 4.5.2h.3 the purpose of verifying that the sum of the injection line flow rates meets or exceeds a minimum value _is to ensure that an ECCS flow to all injection points at least equals the value .

assumed'in the ECCS analyses.

The existing acceptance value in Technical Specifications for the sum of the injection line flow rates for the-Residual Heat Removal (RHR) pump lines _with a single pump running. is 2828 gpm. Since the intent of Technical Specification _ Surveillance Requirement 4.5.2h.3 is to verify the total flow through all four RilR pump _ injection-lines, an acceptance value of at least 3686.4 gpm is required to ensure that the minimum RHR flow will be provided to the core during- a design basis accident.

Failure to provide this minimum flow could result in an insufficient removal of decay heat and possible core damage.

A review of UFSAR sections 5.4.1 and 6.3 verifies that the proposed change does not alter the design, function, or operation of the-RHR system. This proposed change does not effect any existing accident analyses, and it does not introduce the possibility of any accidents or malfunctiot.s not already analyzed. Since the: proposed change is increasing the current acceptance value for injection : line flow to the more

- conservative value. used in the accident analysis,- it does not decrease the- margin of safety . as defined in ~ the Technical Specification . bases - but preserves the margin originally assumed.

While a lower acceptance value for the sum of the RHR injection line flow rates is currently in Technical Specification Surveillance Requirement 4.5.2h.3, the system flow rate was _ verified to be greater - than _3868.4 gpm during titial testing _

(Westinghouse Low Head Safety' Injection Test Procedure TAC 02). North Atlantic has verified that the RilR- system was always capable of performing-its ECCS design function as reported in LER 92-002-00.

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V. Determination of Sinnificant lla7ards for I.icense Amendment Reouest 92-12 Proposed Chance =

(1) The proposed ~ change does not involve a significant increase in the probability or consequences of an accident previously evaluated, The proposed change to Technical Specification Surveillance Requirement,4.5.2b.3 -

revises the acceptance value of the sum of the injection line flow rates with a ringle pump running to conform with the value used in the Seabrook Station Emergency Core Cooling System (ECCS) analysis performed by Westinghouse. This revised acceptance

- value is more conservative than the current Technical Specification value.

The Residual Heat Removal (R11R) System provides the low head ECCS flow necessary in the event of a Loss of Coolant Accident (LOCA). ECCS flow must be sufficient to. remove the stored heat and fission product decay heat from the reactor core to prevent fuel damage that might impair effective cooling of the eore.

The Seabrook Station ECCS analysis is based on the calculated flow rate down three of the four RilR injection lines since the fourth line is assumed to : Spill to containment. The calculated flowrate down three of the four injection lines'in this analysis is 2828.4 gpm. The calculated total pump flow rate down all four injection

, lines _is 3868.4 gpm. Since the actual values used in the analysis for the total _ flow rate down three and four injection lines are 2712 gpm and 3828 gpm, respectively, the proposed value of 3869 gpm, which includes an allowance of 5% for pump-degradation, is conservative.

Technical Specification Surveillance Requirement 4.5.2h.3 is performed as part of.a ~

flow balance test during shutdown when modifications to the ECCS subsystems have been made that alter the subsystem flow characteristics. This surveillance requirement verifies that after the modification the total ECCS flow to the reactor core is equal to or greater than the flow assumed in the ECCS analysis.

The proposed change to Technical Specification Surveillance Requirement 4.5.2h.3 does not alter the design of the RilR system or any other plant system. The RilR system design parameters and operation are not changed, The proposed change is necessary to correct an error in the Technical Specifications whereby the acceptance value for the flow rate through three injection lines was inadvertently used instead of the correct flow rate value through four injection lines. In addition, the revised acceptance value in the proposed change is more conservative than the existing valuci -i Therefore, this proposed change does not increase the probabili_ty of an accident previously evaluated nor will it increase the consequences of any accident.

(2) The proposed change does not create the possibility of a new or different kind of .

accident from aay accident previously evaluated.

The proposed change to Technical Specification Surveillance Requirement 4.5.2h.3 does not affect the design, function or operation of the RilR system. As a subsystem.of the Seabrook Station ECCS, the RilR System will continue to be capable of injecting low pressure cooling water in the event of a LOCA to remove stored and fission product decay heat,and maintain effectir core cooling. The acceptance value for the sum of the RilR injection line flow . tes with a single pump running is more ,

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4 conservative than the value being replaced and meets the value used in the design

-basis Seabrook Station ECCS analysis.

There are no new failure modes introduced by'this. proposed change. its intent is to correct an error in the existing Technical Specifications whereby the acceptance value for the sum of the flow rates in three-lujection lines was used .instead of the value.

for the sum of four injection lines. Therefore, the possibility of a new or d_ifferent kind of accident than those already evaluated is not created by this proposed change.

(3) The proposed change does not result in a significant reduction in -the margin of ,

safety.

The Technical Specification Ilases state that the purpose of the surveillance requirement for flow b*ilance testing following modifications to ECCS subsystems that might alter the subsystem flow characteristics is to verify that proper ECOS flow will be maintained in the event of a LOCA. Proper ECCS flow is defined by the design basis ECCS analysis. The Scabrook Station ECCS analysis used a calculated flow rate value for the sum of the four injection line flow rates of 3868.4 gpm. The acceptance value for the sum of the four injection line flow rates which is currently in Technical Specification Surveillance Requirement 4.5.2h.3 is less than 3868.4 gpm. The proposed change revises the acceptance value in the surveillance requirement to 3869 gpm.

Since the proposed change is resising the acceptance value to a more conservative value which is bounded by the design basis ECCS analysis, the change will not reduce the margin of safety.

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VI. IInvironmental Impact Assessment North Atlantic has reviewed the proposed license amendment = against the criteriu of.-

10CFR$1.22 for environmental considerations,. The proposed changes do not involve a .,ignificant hazards consideration, nor increase the types a nd amounts _of effluents' (hat ' may - be released offsite, not significantly increase -ladividual . or -- cumulative

. occupational radiation c?posures. Based on the foregoing, North Atlantic' concludes that the proposed change meets the -criteria delineated in 10CFR51,22(c)(9)'for 'a categorical exclusion from the requirements for an Environmental Impact Statement, i

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