ML20133L027
| ML20133L027 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 08/02/1985 |
| From: | Gucwa L GEORGIA POWER CO. |
| To: | Stolz J Office of Nuclear Reactor Regulation |
| References | |
| 1926N, NED-85-550, TAC-59404, TAC-59405, NUDOCS 8508120464 | |
| Download: ML20133L027 (3) | |
Text
Georgia Power Company 333 Piedmont Avenue N!anta, Georgia 30308
'Tekphone 404 526 6526 Maing Address-Pot t Ot!;ce Bcx 4545 Atlanta, Geergta 30M h
Georgia Power L T. Gucwa tre soottwm Nxfnc system Manager Nuclear Engineering and Chief Nuclear Engineer NED-85-550 1926N August 2, 1985 Director of Nuclear Reactor Regulation Attention: Mr. John F. Stolz, Chief Operating Reactors Branch No. 4 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D. C. 20555 NRC DOCKETS 50-321, 50-366 OPERATING LICENSES DPR-57, NPF-5 EDWIN I. HATCH NUCLEAR PLANT UNITS 1 AND 2 DETECTION AND SUPPRESSION OF THERMAL-HYDRAULIC INSTABILITY Gentlemen:
General Electric Company (GE) recently informed Georgia Power Company (GPC) that the NRC has approved Amendment 8 to GESTAR II (NEDE-240ll-P-A).
The NRC Safety Evaluation Report (SER) for this amendment requires those plants with a core thermal hydraulic stability ratio greater than 0.8 analyzed under the provision of GESTAR II Amendment 8 to implement and incorporate into plant technical specifications the recommendations of GE Service Information Letter (SIL) 380 - Revision 1.
GPC wishes to maintain the flexibility to load and operate Hatch 1 for cycle 10 (reload 9), which will be analyzed as specified in GESTAR II Amendment 8, under the provisions of 10 CFR 50.59.
Therefore, although no notification of a requirement to submit Technical Specification changes has been received, GPC wishes to quickly resolve this issue so that Unit I restart, scheduled for February 1986, may proceed as planned. At GPC's request, GE has inquired of the NRC Division of Systems Integration whether Core Performance Branch implementation of the SIL-380 recommendations by procedures rather than Technical Specifications would be satisfactory.
GE was informed that the NRC staff still believes Technical Specifications will be required.
GPC herein presents our position on this matter and requests that the staff evaluate our approach to implementation of the SIL recommendations.
We wish to resolve this issue prior to September 15, 1985, to allow sufficient time for any required amendments associated with the first Hatch core reload affccted by GESTAR II Amendment 8 to be submitted without impact on the schedule for plant restart.
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Geoq,ia Power A Director of Nuclear Reactor Regulation Attention: Mr. John F. Stolz, Chief Operating Reactors Branch No. 4 August 2, 1985 Page Two GPC submits that implementation of Technical Specification requirements to perform the recommendations of SIL 380 (i.e., monitoring of APRM and LPRM signal noise due to neutron fiux variations) is inappropriate for the following reasons:
1.
It is not expected, to the best of our knowledge, that core thermal-hydraulic instability of the nature intended to be precluded by the SIL recommendations could lead to violation of fuel design limits specified in GESTAR II.
The SIL recommendations, although prudent, are not significant operational limitations important to providing assurance that the facility be operated without undue hazard to public health and safety and are, therefore, not needed in Technical Specifications.
2.
The requirement that such operational recommendations be enforced by Technical Specifications is inconsistent with ongoing NRC and industry initiatives to:
reduce the scope of the operating licensing requirements embodied in Technical Specifications; reduce the need for NRC review and approval of amendments; and permit application of available NRC and utility resources to matters of direct importance to safe operation.
3.
GPC has operated the two Hatch units for a total of thirteen operating cycles without any indication of unstable operation or limit cycles.
Many of these operating cycles have had calculated decay ratios in excess of 0.8 when conservatively analyzed at a power-flow point of natural circulation and the 105% rod line.
One should note that this analyzed point is in a region of the power-flow map beyond that where operation is allowed under current Hatch Technical Specifications.
4.
Both Hatch units presently have Technical Specifications which prohibit operation without forced circulation and which limit operation with a single recirculation loop to conditions where core decay ratios are relatively low.
Operation with two recirculation
- pumps, even at minimum pump
- speed, is unlikely to produce significant core power oscillations.
5.
GPC has previously implemented operating procedures that enforce adherence to the key provisions of SIL 380, Revision 1 (please refer to our letter " Confirmation of Telephone Conversation ARTS," submitted to your office on June 25, 1984).
We are presently instituting additional procedures to fully implement all the recommendations of SIL-380, Revision 1.
L
Geor laPower A Director of Nuclear Reactor Regulation Attention: Mr. John F. Stolz, Chief Operating Reactors Branch No. 4 August 2, 1985 Page Three 6.
It is very difficult to define effective and concise requirements for performing neutron flux monitoring with existing instrumentation.
The appropriate format for such requirements is in plant procedures where a sufficient level of detail may be provided, and where situations requiring specific exercise of judgment may be identified.
GE has stated that they concur with our position regarding the adequacy of procedural enforcement of the SIL in providing appropriate response to core instability.
In consideration of the short time available to resolve this issue and preserve the option to load and operate cycle 10 under 10 CFR 50.59, we request your prompt attention to this matter to support our proposed schedule for resolution by September 15, 1985.
Should you have any questions regarding this request, please contact this office.
Very tru'y yours, d4 E.h /k i
L. T. Gucwa CBS/mb xc: Mr. J. T. Beckham, Jr.
Mr. H. C. Nix, Jr.
Dr. J. N. Grace (NRC-Region II)
Senior Resident Inspector