ML20217F401
| ML20217F401 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 03/24/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20217F398 | List: |
| References | |
| NUDOCS 9803310399 | |
| Download: ML20217F401 (3) | |
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SAFETY EVALUATION BY THE OFFICE QF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS.9naANDi otto FACILITY OPERATING LICENSE NOS. PPR-70 AND DPR-75 PUBLIC SERVICE ELECTRIC & GAS COMPANY PHILADELPHIA ELECTRIC COMPANY DELMARVA POWER AND LIGHT COMPANY ATLANTIC CITY ELECTRIC COMPANY SAI FM NUCLEAR GENERATING STATION. UNIT NOS.1 AND 2 DOCKET NOS. 50-272 AND 50-311
1.0 INTRODUCTION
By letter dated November 4,1997, the Public Service Electric & Gas Company (the licensee) submitted a request for changes to the Salem Nuclear Generating Station, Unit Nos.1 and 2, Technical Specifications (TSs). The requested changes would revise the Salem Unit 2 containment systems surveillance test acceptance criteria in TS 3/4.6.2 for the contair.mont spray pumps. ' Specifically, the change would replace the minimum specified discharge pressure requirement with an acceptance criterion based on pump differential pressure. Since this surveillance requirement is not currently included in the Salem Unit 1 TSs, the proposed change would add this requirement to TS 3/4.6.2.
2.0 EVALUATION in its letter of November 4,1997, the licensee proposed to modify the TSs surveillance test acceptance criteria in TS 3/4.6.2, " Containment Spray System," for Salem Unit 2. In TS 4.6.2.1, the containment spray system is demonstrated to be operable, in part, by verifying that on recirculation flow, each containment spray (CS) pump develops a discharge pressure of greater than or equal to 215 psig (pounds per square inch gauge) when tested pursuant to TS 4.0.5.
Specifically, the licensee proposed to replace the pump discharge pressure acceptance criterion (TS 4.6.2.1.b) with a criterion based on pump differential pressure.
The containment spray system (CSS) automatically sprays cooling water into the containment atmosphere in the event of a loss-of-coolant accident (LOCA) to limit the peak containment pressure. This action ensures that the containment pressure does not exceed the design value for the containment structure. The CSS is designed to spray at least 2600 gpm of borated water into the containment whenever two out of the four hig4high containment pressure signals occur.
The CS pumps take suction from the RWST and the contents of the spray additive tank are mixed into the spray stream to enhance iodine removal capability. The CS pump recirculation line flow is passed through an eductor which draws on the spray additive tank and then to the CS 9803310399 900324 PDR ADOCK 05000272 P
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. pump suction. When the RWST reaches the low-low level alarm point, CS pump flow is discontinued, and containment pressure control is maintained with the residual heat removal system functioning through the CSS headers.
The discharge head or pressure of a centrifugal pump is a combination of the suction head, the dynamic head, and other velocity factors. The dynamic head is the energy imparted to the process liquid by the pump impeller between the points where suction and discharge heads are measured. The difference in measured pressure between the suction and discharge is the pump differential pressure. Thus, the CS pump discharge pressure will very with changes in suction pressure. The design discharge head of the CS pumps is sufficient to continue at rated capacity with a minimum level in the RWST against a head equivalent to the sum of the design pressure
' of the containment, the head of the uppermost spray nozzles, and the line and nozzle pressure losses.
The CS pumps are tested individually by establishing flow through the miniflow recirculation line.
This test monitors CS pump performance as compared to the expected pump discharge head as determined from the pump characteristics curve, in its letter of May 14,19g7, the licensee stated that the Salem accident analysis is based upon the CS pumps' ability to develop a total differential head greater than 204 psid (pounds per square inch differential) when 300 gallons per minute (gpm) flows through the test recirculation line. Additionally, the licensee noted that the currently specified surveillance requirement of a 215 psig does not ensure, for all instances, that 3
the accident analysis total differential head is met. While in operational modes 1 (power j
. operation) through 4 (hot shutdown), the minimum required RWST volume results in a CS pump suction pressure of approximately 26 psig. With this suction pressurs, assuming minimal suction line loss, the current discharge pressure acceptance criterion would provide only 18g psid.
Since the total dynamic head (as measured by the pump differential pressure) is the measure of pump performance, the NRC staff finds the change to this specified criterion is acceptable.' The staff also finds that the proposed value for this acceptance criterion of 2 204 psid when added to
- the pump suction pressure corresponds to the expected operating point on the pump head characteristic curve in Figure 6.2-5 of the Salem Updated Final Safety Analysis Report.
Therefore, the NRC staff finds the proposed change to Salem Unit 2 TS 4.6.2.1 to be acceptable.
Since the proposed addition of TS 4.6.2.1.b to Salem Unit 1 adds a requirement that currently does not exist and is the same as to the proposed surveillance requirement for Salem Unit 2, the NRC staff finds this change to be acceptable.
The change in the numbering of the requirements in Salem Unit 1 TS 4.6.2.1 and the removal of a duplicate word in Salem Unit 2 TS 4.6.2.1.b.2 are administrative in nature and are acceptable.
3.0 STATE CONSULTATION
.in accordance with the Commission's regulations, the New Jersey State official was notified of the proposed issuance of the amendments. The State official had no' comments.
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4.0 ENVIRONMENTAL CONSIDERATION
The amendments change surveillance requirements. The NRC staff has determined that the amendments involve no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding (62 FR 66141). Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(g). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.
5.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the
' Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
' Principal Contributor: P. Milano Date: March 24, 1998 I
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