ML20044B233
| ML20044B233 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 07/09/1990 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20044B232 | List: |
| References | |
| NUDOCS 9007180178 | |
| Download: ML20044B233 (2) | |
Text
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!marog'o, UNITED STATES
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',i NUCLEAR REGULATORY COMMISSION i
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l SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 52 TO FACILITY OPERATING LICENSE NO. NPF-49 NORTHEAST NUCLEAR ENERGY COMPANY ET AL.
I MILLSTONE NUCLEAR POWER STATION, UNIT NO. 3 DOCKET NO. 50-423 i
INTRODUCTION By application for license amendment dated March 30, 1990, Northeast Nuclear Energy Company, et al. (the licensee), requested changes to Millstone Unit 3 TechnicalSpecifications(TS).-
The proposed amendment would change the values in Technical Specification (TS)
Table 3.3-4, " Engineered. Safety Features Actut. tion System Instrumentation Trip Setpoints", associated with the steam generator water level setpoint.
DISCUSSION AND EVALUATION The Hillstone Unit 3 Engineered Safety Features Actuation Sy(SG high-high) stem (ESFAS)is provided with a "high-high" steam generator level setpoint that, when actuated, srovides a turbine trip and feedwater isolation. The 1
purpose of'the SG hig1-high trip is to prevent overfilling of the steam l
generators, The proposed revised setpoint will lower the SG 1evel (narrow range) at which a turbine trip and feedwater isolation will occur. The current trip setpoint is at-82% narrow range level. The proposed revised trip setpoint is 80.45%
i level. The proposed changes are necessary due to an increase in revised channel statistical allowances for abnormal :nvironmental conditions. The i
associated values for total allowance (TA), statistical sum of errors
. excluding sensor and instrument rack errors (Z), sensor error (S), and allowable value for turbine trip and feedwater isolation on high-high SG water 1evel would be changed accordingly, j
The SG high-high trip is credited in terminating the excess feedwater event as
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. described in Section 15.1.2, "Feedwater System Malfunctions that Result in ar, Increase in Feedwater Flow" of the Millstone Unit 3 FSAR. The revised setpoint assures that an isolation signal will be generated as assumed in the analysis.
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The revised SG high-high trip is calculated using the currently approved Millstone Unit 3 (Westinghouse) setpoint methodology as described in WCAP 10991, " Westinghouse Setpoint Methodology for Protection Systems, Millstone Unit No. 3" which is also used to calculate the other trip setpoints in TS Table 3.3-4.
Since the change in trip setpoint is minor, the projected course of the excess feedwater event will not change.
The proposed change will enhance the safety performance of the ESFAS since the feedwater isolation will be. initiated sooner, i
Based upon the above, we conclude that the proposed changes to TS Table 3.3-4 i
are acceptable, j
ENVIRONMENTAL CONSIDERATION
.This amendment changes a requirement with respect' to installation or use of a facility component located within the re:stricted area as defined in 10 CFR Part
- 20. We have 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 staff has previously
)ublished a proposed finding that the amendment involves no significant lazards consideration and there has been no public comment or, 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.
CONCLUSION 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 manner and(2)suchactivitieswill 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.
Dated: July 9,1990 Principal Contributor:
D. Jaffe l
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