ML20210D278
| ML20210D278 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 09/10/1986 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20210D275 | List: |
| References | |
| NUDOCS 8609190105 | |
| Download: ML20210D278 (2) | |
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NUC?. EAR REGULATORY COMMISSION tk, / 4, J{p h CASHINGToN, D. C 20555 v
- f ShFiTY EVf.LUATIGN BY THE OFFICE OF NUCLEAR REACTOR REGULATION pELATED TG FACILITY OPERATING LICENSE NO. NPF-6 ARKANSAS POWER AND LIGHT COMPANY A,RKANSAS NUCLEAR ONE, UNIT 2 O0CKET NO. 50-368
- 1. 0 IN!'RODUCTION Sy letter dated April 25, 1986, Atkansas Power and Light Company (AP&L) submitted a request to reend Facility Operating License No. NPF-6 for the Arkansas Nuclear One-Unit 2 (ANO-2) plant. The request was for proposed thanges to the Technical Specifications involving e more negative moderator temperature coefficient (MTC), an increase in the refueling water tank (RWT) maximum solution temperature, and an increase in the required shutdown ms.rgin for Modes 1 through 4.
This Safety Evaluation addresses the proposed changet related to hTC The remainder of the proposed changes will be the subject of a separate Safety Evaluation.
- 2. 0 EVALUATION The proposed charge tp Technical Specificagion 3.1.1.4 will lower thg allowable MTC negative limit. to -3.4 x 10 Ak/k/ F from -2.8 x 10 ok/k/ F.
This thange is required to accomnodate the longer than originally plagned cycle length anticipated for Cycle 6.
A negative MTC has an adverse effect on events which result in cooldown of the reactor coolar,C iyetem (RCS) since it results in a positive reactivity addition.
The licensee has stated that the most limiting RCS cooldown accident associated with a deurease in the MTC is the steam line break (SL8) event.
At the staff's request, the licensee submitted the results of a reanalysis of the SLB event by letter from T. Gene Campbell to George W. Knighton dated May 23, 1986. The results for SLB events initiated from hot full power with and without loss of AC power, and from hot zero power with and without loss of AC _oower shcw that the Cycle 6 ped post-trip reactivities are less limiting than those originally reported in the ANO-2 FSAR.
The hot zero power case with loss of AC power resulted in a peak return to pcwer of 1.55% for Cycle 6 as compared to the FSAR Cycle 1 result of 43.2%
power.
The LLB event for Cycle 6 is thus bounded by the conclufions reported in W.e FSAR and the ;bange tc the more negative MTC Technical Specification l'imit is, therefore, acceptaolk f
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_2 3.0 EVALUATION
SUMMARY
Based on the staff evaluation of the results of the licensees' reanalysis described above, the proposed change to ANO-2 Technical Specification 3.1.1.4, " Moderator Temperature Coefficient", is acceptable.
4.0 ' ENVIRONMENTAL CONSIDERATION This amendment involves a change in the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20.
The 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 exposu're. The Commission has previously published a proposed finding that the amendment involves no significant hazards consideration and there has been no public comment on such finding. 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
We have concluded, based on the considerations discussed above, that (1) there is reascnable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Commission's regulations, and 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 contributor to this SE was L. Kopp Dated: September 10, 1986 i
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