ML17055C927
| ML17055C927 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 03/24/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17055C925 | List: |
| References | |
| NUDOCS 8703310565 | |
| Download: ML17055C927 (4) | |
Text
gy,S REMI (4
P
~O n
~ C O
++*<<+
I UNITEC STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, O. C. 20555 SAFETY EVALUATION BY THE OFFICF OF NUCLEAR RFACTOR REGULATION SUPPORTING AMENDMENT NO.
2 TO FACILITY OPFRATING LICFHSE NO.
DPR-63 NIAGARA MOHAWK VOWeR CORPORATION NINE MILE POINT NUCLFAR STATION, UNIT NO.
1 DOCKET HO. 50-220
1.0 INTRODUCTION
By application dated October 30, 1986, as supplemented January 15,
- 1987, Niagara Mohawk Power Corporation (the licensee} requested an amendment to Appendix A of Facility Operating License No.
DPR-63 for the Nine Mile Point, Nuclear Station, Unit No.
1 (NMP-1).
The amendment would modify Fioures
- 2. 1.1 and 3.].?.aa in the Appendix A Technical Specifications (TS) regardT'ng the limiting relationships between core power and core flow rate.
Specifically, the changes to Figures 2.1. 1 and 3.1.?aa would reflect changes to:
(1} reduce a restriction on the reactor operating range, and (2} provide consistency with the current reload analyses For the present Nine Mile Point Unit 1 core configuration and parameters.
In support of the proposed modification, the licensee provided General Flectric Company (GE} Report, NFDC-31126, "General Electric Boiling Mater Reactor Extended Load Line Limit Analysis for Nine Mile Point 1 Cycle 9" dated February 1986.
- 2. 0 EVALUATION Presently, the NMP-1 TS limit full power operation to the flow rane'e from 91%
to 100$.
The Extended Load Line Limit Analysis (ELLLA) provides the basis for reactor opera.',on in the regior bounded by the 108K average power range monitor (APPM) rod block line (See Figure 2. 1. 1) and the licensee Power.
'Ihe present Power/Flow line was reviewed and approved in the Staff's Safety Evaluation supporting Amendment No.
36 to Facility Operating License No.
DPR-63 dated March 29, 1980.
The requested change affects a relatively small triangular area of the Power/Flow Map for core power between 85 and 100% and core flow betvIeen 61 and 91%.
A GE safety analysis (NEDC-31126, February 1986) was performed to demonstrate that the consequences of transients and acciderts initiated from within the expanded ELLLA region are bounded by the conseouences of the same events initiated from the licensing basis condition for NMP-1, Cycle 9.
Consideration was also given to overpressure protection for compliance with the American Society of Mechanical Engineers (ASME) Pressure Vessel
- Code, and reactor core thermal-hydraulic stability.
Principal considerations in the review of the expanded ELLLA for NMP-1 include:
1.
The slope of the rod block line has been previously reviewed and approved for NMP-1 (Amendment No. 36, Marcl 28, 1980} and is generally applicable.
8703310 05000220 565 870324 PDR ADOCK PDR P
~ g I
ll
'I
'F'lYta1 'V I, t I
2.
3.
The limiting transients initiated within the proposed expanded ELLLA region are still limiting at 100K power/100K flow (See Table 3-2 of GE NEDC-31126, February 1986).
Therefore, no change in the present operating limit minimum critical power ratio (MCPR) of'.40 is required.
The effect of less than rated flow on loss-of-coolant accident analyses has been generically reviewed and approved f'r referencing (NRC Letter to GE dated May l9, 1978).
No changes to the present maximum average planar linear heat generation rate (MAPLHGR) limits are requi red.
4.
The calculated peak pressure for main steam isolation valve closure without scram increases by I psi which results in a value 46 psi below the allowable 1375 psi ASME Pressure Vessel Code limit for over pressure protection and thus remains acceptable.
5.
The proposed extended ELLLA region is beyond the region of thermal-hydraulic stability (THS) concerns; therefore the THS requirements identified in NRC Generic Letter 86-02 (January 23, 1986>
remain satisfied.
Based on our review of the anticipated changes in core behavior, we conclude that the proposed changes correctly address the proposed extended operating region and are, therefore, acceptable.
The revised fiqures reflect the new flow-biased scram and APRM rod block settings and the limiting power flow line.
No changes to the present TS operating limit Minimum Critical Power Ratio or MAPLHGR limits are required.
3.0 ENVIRONMENTAL CONSIDERATION
This amendment involves a change to a requirement with respect to the installation or use of a facility component located withir the restricted area as defined in 10 CFR Part 20.
The staff has determined that the amendment
'nvolves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released nffsite and that there is no significant increase in individual or cumulative occupational radiation exposure.
The Commission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public comment on such finding.
Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to IO CFR 51.22(b) no environmental impact statement nor environmental assessment need be prepared in cornection with the issuance of this amendment.
- 4. 0 CONCLUSION The staff has concluded, based on the considerat',ons discussed above, that:
(1) there is reasonable assurance that the health and safety of the public wi11 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 this amendment will not be inimical to the common defense and security nor to the health and safety of the public.
Principal Contributor:
M. McCoy Dated:
March 24, 1987
I 4