ML20235M589

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Proposed Tech Spec,Revising Section 4.5.A.3.d to Specify LPCI Pump Performance Neccesary to Comply W/Current LOCA Analysis for Plant
ML20235M589
Person / Time
Site: Pilgrim
Issue date: 07/08/1987
From:
BOSTON EDISON CO.
To:
Shared Package
ML20235M572 List:
References
NUDOCS 8707170247
Download: ML20235M589 (5)
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, ,. ATTACHMENT A-Proposed Chanae Technical Specification section 4.5.A.3.d is being revised to explicitly specify the pump performance necessary to comply with the current LOCA analysis for Pilgrim Station.

Proposed 4.5.A.3.d will state:

Each LPCI pump shall pump 4800 gpm at a head across the pump of at least 380 fi.

Reason for Change The proposed specification specifies the performance of a single pump. The existing specification is based on three pumps. The three pump case is no longer a limiting case in the Pilgrim LOCA analysis, and is not analyzed as part of that analysis. Instead, two pump and four pump configurations are-used. By specifying pump performance for a single pump, testing will be made easier and more accurate, the data provided by the surveillance will be easier to trend, and pump degradation will be easier to detect.

The rewording also states pump capacity requirements in terms which do not need to be translated by intermediate calculations to be used in surveillance procedures. This is presently the case because the three pump configuration is not directly tested.

Safety Evaluation and Determination of No Significant Hazards Considerations The proposed amendment restates an existing surveillance test to clarify it, make it consistent with the most current Pilgrim LOCA analysis, and remove the need for intermediate calculations to translate the Technical Specification requirement into surveillance procedures.

The Code of Federal Regulations,10CFR50.91 requires that at the time a licensee requests an amendment, it must provide to the Commission its analysis, using the standards in 10CFR50.92, about the issue of no significant hazards consideration. Therefore, in accordance with 10CFR50.91 and 10CFR50.92 the following analysis has been performed.

1. The operation of Pilgrim Station in accordance with the proposed amendment will not involve a significant increase in the probability or consequences of an accident previously evaluated.

1 The current Pilgrim Technical Specification 4.5.A.3.d requires three LPCI pumps to deliver 14,400 gpm against a system head corresponding to a ,

vessel pressure of 20 psig. This requirement is based on' the original core LOCA analysis which showed that this flow from three LPCI pumps l would maintain fuel clad temperatures below the original design j acceptance criteria of 2,700 *F. However, this analysis has been i superseded by 10CFR50 Appendix K, which does not address the 4 configuration of 3 LPCI pumps injecting to the vessel, but does consider the following single failure conditions:

Failure Systems Remainina Operable (PCI Injection Valve 2 LPCS + HPCI + ADS Diesel Generator 1 LPCS + 2 LPCI + HPCI + ADS i HPCI 2 LPCS + 4 LPCI + ADS' 8707170247 070708 F PDR- ADOCK 05000293 P

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.The three-LPCI pumps injecting into 9he vessel is no longer a limiting.

case, and it is not used in the present design bases except that the flows into the vessel for the analyzed cases are derived from the present

. three pump specification. Thus, the proposed specif cation preserves the I individual pump performance required by the three pump case to ensure that flows for the analysed cases are unchanged.

The proposed specification is based on calculations of the pressure drop 1 with three pumps injecting into the reactor pressure vessel at 20 psig. I To assure conservatism, the three pump configuration with the greatest j pressure drop was chosen for the calculation, and a friction loss 20% 1 above that for clean pipe was assumed. The pump design curve pump head 1 was reduced to where a flow of 14,400 gpm was obtained. It was I determined that approximately an 11% reduction would produce the required flow. The proposed specification allows only a 9.5% reduction for added l conservatism.

The Technical Specification will now be directly tied to pump performance. The actual flow to the vessel during a LOCA depends on the l pump and piping configuration used in the several cases included in the l LOCA analyses.

l The proposed change does not reduce the LPCI pump capacity requirements.

It restates the requirements in clearer language commonly used for specifying pump capacity. The pump capacity requirec' by the proposed Technical Specification ensures pump performance necessary to comply with Pilgrim's LOCA analysis. Therefore, this change will not result in a significant increase in the probability or consequences of an accident previously evaluated.

2. The operation of Pilgrim Station in accordance with the proposed amendment will not create the possibility of a new or different kind of accident from any accident previously evaluated.

The proposed change restates the LPCI pump requirements in clearer language. It assures that pump capacity complies with that required by the Pilgrim LOCA analysis; hence operating Pilgrim in accordance with this change will not create the possibility of a new or different kind of accident from any accident previously evaluated.

3. The operation of Pilgrim Station in accordance with the proposed amendment will not involve a significant reduction in the margin of safety.

The current Technical Specification 4.5.A.3.d contributes to the margin ,

of safety by assuring that LPCI pumps can generate sufficient flow to prevent Peak Cladding Temperatures (PCT) from rising such that the fuel cladding degrades (acceptance PCT is 2200*F). The proposed change restates the pump capacity, but does not change the capacity from that used in Pilgrim's LOCA analysis. Therefore the margin of safety assured by 4.5.A.3.d is unchanged, and operating Pilgrim in accordance with the ,

change will not involve a significant reduction in the margin of safety. l This change has been reviewed and approved by the Operations Review Committee, and reviewed by the Nuclear Safety Review and Audit Committee.

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' ' Schedule of Change .

Thi change will be implemented within 30 days following BECo's receipt of its approval by the Commission.

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ATTACHMENT B 4

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LIMITING CONDITION FOR OPERATION _ SURVEILLANCE REQUIREMENT 3.5.A Core Sp_tay and LPCI Subsystems 4.5.A Core Sorav and LPCI Subsystems (cont'd) (cont'd)

Check Once/ day Calibrate Once/3 months Test Once/3 months

2. From and after the date that one 2. When it is determined that one (

of the core spray subsystems is ccre spray subsystem is made or found to be inoperable inoperable, the operable core for any reason, continued reactor spray subsystem, the LPCI operation is permissible during subsystem and the diesel the succeeding seven days, generators shall be demonstrated provided that during such seven to be operable immediately. The days all active components of the operable core spray. subsystem other core spray subsystem and shall be demonstrated to be active components of the LPCI operable daily thereafter.

subsystem and the diesel generators are operable.

3. The LPCI Subsystems shall be 3. LPCI Subsystem Testing shall be as operable whenever irradiated fuel follows:

is in the reactor vessel, and prior to reactor startup from a a. Simulated Once/ Operating Cold Condition, except as Automatic Cycle specified in 3.5. A.4, 3.5. A.5 and Actuation 3.5.F.5. Test

b. Pump Once/ month Operability l
c. Motor Operated Once/ Month and valve Once/ cycle from operability the Alternate Shutdown Panel
d. Pump Flow Once/3 months Each LPCI pump shall pump 4800 gpm at a head across the pump of at least 380 ft.

Amendment No. 104

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