ML20058L636
| ML20058L636 | |
| Person / Time | |
|---|---|
| Site: | Hope Creek  |
| Issue date: | 12/09/1993 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20058L634 | List: |
| References | |
| NUDOCS 9312170121 | |
| Download: ML20058L636 (3) | |
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NUCLEAR REGULATORY COMMISSION G'
WASHINGTON, D.C. 20556-0001
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 61 TO FACILITY OPERATING LICENSE NO. NPF-57 PUBLIC SERVICE ELECTRIC & GAS COMPANY ATLANTIC CITY ELECTRIC COMPANY HOPE CREEK GENERATING STATION DOCKET NO 50-354
1.0 INTRODUCTION
By letter dated May 18, 1993, and supplemented on October 6, 1993, the Public Service Electric & Gas Company (the licensee) s @mitted a request for changes to the Hope Creek Generating Station, Technical Specifications (TS). The October 6, 1993, supplemental letter provided additional information that did not change the basis for the staff's proposed no significant hazards determination.
The requested changes would revise the surveillance requirements of TS 4.4.1.2, Reactor Coolant Recirculation System Jet Pumps as follows:
1.
The acceptance criteria of TS 4.4.1.2.a.3 and 4.4.1.2.b.3 for the indicated diffuser-to-lower plenum differential pressure of any individual jet pump will be increased from 10% to 20% from established patterns.
2.
TS 4.4.1.2.b, surveillance requirements during single-loop operation to demonstrate operability of the jet pumps at least once every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> will be revised to be applicable only to the jet pumps for the operating loop.
3.
The footnote associated with TS 4.4.1.2.b that requires the gathering of baseline data for two-loop or single-loop operation during startup following any refueling outage will be revised to require gathering single-loop baseline data only after entering single-loop operation.
2.0 EVALUATION The jet pump assemblies are located in two semicircular groups in the downcomer annulus between the core shroud and the reactor vessel wall. Each stainless steel jet pump consists of a driving nozzle, a suction inlet, a throat or mixing section, and a diffuser. The driving nozzle, suction inlet, and throat are joined together as a removable unit, and the diffuser is permanently installed. High-pressure water from the recirculation pumps is supplied to each pair of jet pumps through a riser pipe welded to the recirculation inlet nozzle thermal sleeve.
In the event of a design-basis-accident, an inoperable jet pump could increase the blowdown area and reduce the capability of reflooding the core. TS 3.4.1.2 requires unit shutdown in the event of one or more jet pumps becoming inoperable.
Jet pump operability is monitored by TS surveillance requirement 4.4.1.2, which checks jet pump performance daily for significant degradation.
9312170121 931209 PDR ADOCK 05000354 P
. The proposed change to increase the acceptable limit for the indicated diffuser-to-lower plenum differential pressure of any individual jet pump from 10% to 20% from established patterns is to account for turbulence in the jet pump diffuser where the flow measurement tap is located. The turbulence results in noise being generated in the differential pressure signal.
Attempts to filter the noise have not been completely successful; and the remaining noise causes constant motion in the individual jet pump D/P indicators. The new acceptance limit is consistent with the recommendations of General Electric SIL 330 and is adequate to detect significant degradation in jet pump performance and is acceptable.
The proposed change to make the daily surveillance requirement for demonstrating operability of the jet pumps applicable only for the operating loop jet pumps during single loop operation will provide an acceptable level of safety. Without forced flow, the inactive loop jet pump diffuser-to-lower plenum differential pressures are much lower than those in the operating loop, and difficulty has been experienced in satisfying the surveillance requirements. During single loop operation, stresses are much lower on the inactive jet pump assemblies and their support structures.
It is unlikely that jet pumps that were found to be operable prior to entering single loop operation would degrade when the loop is inactive.
Surveillance testing of the inactive loop is not considered necessary.
This position is consistent with the recommendations of General Electric SIL 517 and is acceptable.
In its original submittal dated May 18, 1993, the licensee proposed to eliminate the footnote associated with TS 4.4.1.2.
This footnote requires gathering baseline data for two-loop or single-loop operation during startup following any refueling outage.
In its October 6, 1993, supplement to its original submittal, the licensee proposed to revise the footnote vice deleting it. The revised footnote would allow single-loop operation baseline data to be recorded the first time the unit enters single-loop operation. Two-loop operation baseline data will continue to be collected during startup following any refueling outage. This proposed amendment would eliminate the requirement to trip and restart the recirculation pumps at power during plant startup.
In its May 18, 1993, and October 10, 1993 letters, the licensee stated that baseline data collected during previous operating cycles will initially be utilized to confirm operability. Additionally, the licensee stated that their review of previous operating cycle baseline data for single-loop operation has shown very little change in the D/P from cycle to cycle. Based on the review of the licensee's submittals, the staff finds the licensee's proposal to revise the footnote for TS 4.4.1.2 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 amendment. The State official had no comments.
4.0 ENVIRONMENTAL CONSIDERATION
The amendment changes surveillance requirements. The NRC staff has determined that the amendment involves 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 amendment involves no significant hazards consideration, and there has been no public comment on such finding (58 FR 34090). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
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 amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors:
M. Davis S. Dembek Date:
December 9. 1993 1
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