ML20235J018

Safety Evaluation Supporting Amend 94 to License DPR-61

ML20235J018
Person / Time
Site:	Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png
Issue date:	09/10/1987
From:	Office of Nuclear Reactor Regulation
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Shared Package
ML20235J014	List: ML20235J012 ML20235J015 ML20235J018
References
NUDOCS 8710010268
Download: ML20235J018 (3)

Text

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jd#"% UNITED STATES g

p~ \ g NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 205%

SAFETY EVALUATION DY_THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 94 TO FACILITY OPERATING LICENSE N0. DPR-61

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CONNECTICUT YANKEE ATOMIC POWER COMPANY HADDAM NECK PLANT p0CKETNO.50-213

1.0 INTRODUCTION

By letter dated June 1,1987, the Connecticut Yankee Atomic Power Company (CYAPCO) submitted a request for changes to the Haddam Neck Plant Technical Specifications.

The license amendment revises the heat-up rate curve (Figure 3.4-8) and also provides a larger interval for which the low-temperature over pressurization

. protection system (LTOPS) must be placed into operation. More specifically, the proposed heat-up rate change results in a pressure / temperature limit curve shift. This shift increases the temperature range over which the LTOPS can effectively be placed into operation and decreases the probability I

of operator error during plant heat-up and cooldown operations.

2.0 BACKGROUND

By letter dated June 1,1987, Connecticut Yankee Atomic Power Company (the licensee) submitted a proposed change to the plant Technical Specifications to incorporate a revised pressure-temperature, heat-up curve. The proposed change is intended to provide a larger temperature interval before which the LTOPS must be placed into operation. Presently, the plant Technical Specifi-cations require that the LTOPS be in operation (hence, HPSI pumps are disabled) when the RCS temperature is less than 340 F. 340 F corresponds to the HPSI pump shutoff head of 1500 psi based on the heat-up curve. Under the proposed revision to the pressure-temperature, heat-up curve, the allowable minimum temperature for the 1500 psi HPSI pump shutoff head would be reduced from 340 F to 315"F. As before, the revised pressure-temperature curve is intended to be valid for plant operation through 22 EFPY, 3.0 EVALUATION 1 .

The current pressure-temperature limits were approved for incorporation into the plant Technical Specifications based on the staff's finding that the limits me't the safety margins of Appendix G, to 10 CFR Part 50. The basis for this' finding was provided in the staff's Safety Evaluation issued in .

support df Amendment No. 70 to the Facility Operating License.

8710010268 870910 PDR ADOCK 05000213 P pm

i The current pressure-temperature, heat-up limit curve assumes a maximum heat-up rate of 50 F/hr up to an RCS temperature of 200*F and 100 F/hr l up to an RCS temperature of 500 F. The proposed revised curve also assumes a maximum heat-up rate of 50*F/hr up to an RCS temperature of 200 F, but now assumes a heat-up rate of 60'F/hr (in lieu of 100*F/hr) up to an RCS temperature of 550*F. The staff has performed independent calculations to evaluate the proposed pressure temperature curve utilizing the methodology in USNRC Standard Review Plan 5.3.2, NUREG-0800, Rev. 1 July 1981, and the revised heat-up rate assumption. Based on our calculations, we conclude that.the proposed pressure-temperature limits meet the safety margins of i Appendix G,10 CFR Part 50 for 22 EFPY and are acceptable for incorporation '

into the plant's Technical Specifications.

The staff has also evaluated the operational aspect of the proposed change.

The Haddam Neck Plant presently uses two relief trains, each with two motor operated isolation valves and one spring loaded relief valve, for over-J pressure protection during low temperature operating conditions. The i revised P/T curves shows that when the RCS temperature is at 315'F the 1 allowable RCS pressure is 1500 psig, which is the shutoff head of the HPSI l pumps. When the RCS temperature is below 315'F, the allowable RCS pressure 1 is less than the HPSI shutoff head and a mass addition transient could occur. Therefore, the LTOP system is required to be operable and the HPSI pumps are required to be disabled when the RCS temperature is at 315 F during heat-up.

The licensee did not propose a revision of the P/T limits for the cooldown rates specified in Figure 3.4-9. For the Haddam Neck design, heat-up rate curves provide the limiting conditions for determining LTOP system oper- q ability requirements. The licensee's proposed changes to the TS for LTOP i system operation will provide more plant operational flexibility and will i not compromise plant safety. l t

Based on the above evaluation, the staff concludes that the licensee's )

proposed changes to the technical specifications, as submitted in its i letter dated June 1, 1987, meet all applicable regulatory guidance and requirements and are therefore acceptable.

4.0 ENVIRONMENTAL CONSIDERATION

This amendment involves a change to a requirement with respect to the installation or use of facility components located within the restricted area as defined in 10 CFR Part 20 and changes to the surveillance requirements. The staff has determined that the amendment involves ,

no significant increase in the amounts, and no significant change in the types, of any effluents thct may be released offsite and that there is no s'ignificant 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, 1 this amendment meets the eli set forth in 10 CFR 51.22(c)gibility criteriato for (9). Pursuant categorical 10 CFR 51.22(b)exclusion no environmental impact statement or environmental assessment need be prepared in connection with the issuance of this amendment.

5.0 CONCLUSION

The staff has 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) 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 or to the health and safety of the public.

6.0 ACKNOWLEDGEMENT Principal Contributors: C. Liang, XRSB, NRR and E. Murphy, MTEB, NRR 4

Dated: September 10, 1987 i

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