ML20083H033
| ML20083H033 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 12/30/1983 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20083H030 | List: |
| References | |
| TAC-52556, TAC-52565, TAC-52566, NUDOCS 8401120600 | |
| Download: ML20083H033 (4) | |
Text
____
l SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 37 TO FACILITY OPERATING LICENSE NO. NPF-2 AND AMENDMENT NO. 27 TO FACILITY OPERATING LICENSE NO. NPF-8 ALABAMA POWER COMPANY JOSEPH M. FARLEY' NUCLEAR PLANT, UNIT NOS.1 AND 2 DOCKET NOS. 50-348 AND 50-364 INTRODUCTION By letter dated October 13, 1983, Alabania Power Company, licensee for Joseph M. Farley Nuclear Plant Units 1 and 2, submitted a request for an amendment of the Technical Specifications for both units. The Technical Specification changes are intended to accommodate a slightly positive moderator temperature coefficient (MTC) below 70 percent of rated power and an increased enthalpy hot channel factor (Ff ) limit H
below full power. The licensee's submittal included a safety analysis for operation of the Farley units with new core safety limits which were established a's' a result of' these proposed changes.
DISCUSSION AND EVALUATION A.
POSITIVE MODERATOR TEMPERATURE COEFFICIENT The current MTC Technical Specification requires a non-positive value at all power levels. The proposed change allows a slightly positive MTC(+0.5x10~4 ak/k/*F) below 70 percent of rated power and a non-positive value at or above 70 percent of rated power. Therefore, those transients and accidents which are sensitive to a positive MTC were reanalyzed.
In general, these are transients which cause an increase in the reactor coolant temperature such as an uncontrolled rod cluster control assembly (RCCA) withdrawal, uncontrolled boron dilution, partial loss of forced reactor crolant flow, loss of
. external electrical load and/o'r turbine trip, accidental depressur-ization of the reactor coolant system (RCS), complete loss of forced reactor coolant flow, single reactor coolant pump locked rotor, and RCCA ejection.
e4o11206co e31230 DR ADOCK 05000
B. NUCLEAR HOT CHANNEi. FACTOR CHANGE The nuclear hot channel factor is limited by the following relationship:
F 1 1.55[1+K(1-P)] [1-RBP(BU)]
AH where P is the fraction of full power, RBP is the rod bow penalty, and K is a power correction constant. The proposed change will increase K from 0.2 to 0.3 and its effect on the accident analysis is realized through changes to the core safety limits. Since the overtemperature and over-poweraT trip setpoints are based on the core safety limits, the set-points must be verified as being applicable to the new core safety limits. The licensee has verified that the overpower and overtemperature a T protection setpoints are not affected by the proposed FAH multiplier change. This also has been shown to be true for other Westinghouse cores where this power correction has been recently approved. However, since there exists excess conservatism between the current setpoints and the new core safety limits, the licensee has also proposed to modify the overpower and overtemperaturea T setpoints in order to provide improved operating capability. Since there are no FSAR transients which rely on the overpowera T trip, only those transients which rely upon the overtemperature A T trip were reanalyzed by the licensee. These are the RCCA withdrawal at power, loss of external load, and RCS depressurization incidents.
C. REANALYZED TRANSIENTS The reanalyzed transients which have been mentioned in the preceding sactions as~ being impacted by the proposed changes in MTC or over-temperature AT trip setpoint were reviewed. The analysis of these transients used approved methods and computer programs consistent with those employed in the FSAR.
In all cases the results indicate that the safety criteria are met. That is, peak fuel and clad 1
temperatures remained acceptable, minimum DNBR remained above the limitevalue of 1.30, and/or reactor coolant system pressure remained below 110% of design pressure. The results of the reanalyzed transients are, therefore, acceptable.
D.
TECHNICAL SPECIFICATION CHANGES (1) The MTC limits in Specification Limiting Condition of Operation (LCO)3.1.l.3hahebeenchangedtolessthanorequalto0.5X10-4Ak/kOF for the all rods out, beginning of cycle, below 70 percent thermal power condition and to less than or equal to 0 at or above 70 percent thermal power. Westinghouse has performed the necessary transient and accident reanalyses based on the new MTC values and has shown that the limiting conditions and safety criteria are met. The change is, therefore, acceptable.
(2) The 0.2 partial power multiplier in Secifications Bases'B.2.1.1 and LC0 3.2.3 has been changed to 0.3 in order to allow an increased hot channel factor below full power. Historically, increasing the allow-ableFNHwithdecreasingpowerhasbeenpermittedforpreviously approved Westinghouse designs. The Westinghouse safety analysis has shown that the current Farley safety analyses are notaffected by this change. The change is, therefore, acceptable.
(3) TheoverpowerandofertemperatureATsetpointsdefinedinSpecification Table 2.2-1 were revised in order to optimize the available operation-al margin that exists between the setpoints and the new core safety limits (Figure 2.1-1)whichwereestablishedduetotheabove-mentionedF$H change. The constants in these AT setpoints were modified according to the setpoint methodology accepted for all previous Westinghouse cores and described in WCAP-8745, " Design Bases for the Thermal Overpower AT and Thermal Overtemperature AT Trip Functions." Those incidents which rely on these trips were reanalyzed to confirm that the limiting conditions and safety criteria are met. Therefore, the revised overpower and over-temperature AT protection setpoint modifications are acceptable.
(
4-D SAFETY
SUMMARY
We have reviewed the proposed changes to the Farley Units 1 and 2 Technical Specifications allowing operation with a positive moderator temperature coefficient at low power levels and an increased hot channel factor limit below full power. We conclude that reasonable i
assurance has been provided that these modifications will not pose a threat to the health and safety of the public and that the proposed Technical Specification changes are, therefore, acceptable.
1 ENVIRONMENTAL CONSIDERATION We have determined that the two amendments do not authorize changes in effluent types or total amounts, nor increases in power ' levels, and will not result in an significant environmental tapact.
Having made this, determination, we ha've further concluded that the amendments involve actions which are insignificant from the standpoint of environmental impact and, pursuant to 10 CFR 51.5(d)(4), '
that an ' environmental impact statement or negative declaration and environmental impact apprais,al~need not be prepared in connection with the issuance of these amendments.
l CONCLUSI0M We"have 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 mar.ner, and (2) such activities will be conducted in compliance with the conmission's regulations and the issuance of the -amendments will not be inimical to the conimon. defense and security or to the health and safety of the public.
M3 Dated:
l l'
Principal Contributors:
L. Kopp and G. Schwenk I
i w-.--or
,-w-ma,,---,,-,e-,---
,---,--,a-w--n.-,---,--,---a,,-,
-,-,s-
---.e
,- -- -,--, - - - --- ----- -