ML20235L634
| ML20235L634 | |
| Person / Time | |
|---|---|
| Site: | Haddam Neck File:Connecticut Yankee Atomic Power Co icon.png |
| Issue date: | 07/06/1987 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20235L605 | List: |
| References | |
| NUDOCS 8707160768 | |
| Download: ML20235L634 (2) | |
Text
_
- c
'o UNITED STATES l'
"j NUCLE AR REGULATORY COMMISSION
),,
.. c WASHINGTON. D. C. 20555 S
/
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING AMENDMENT NO. 91 TO FACILITY OPERATING LICENSE NO. DPR-61 CONNECTICUT YANKEE ATOMIC POWER COMPANY HADDAM NECK PLANT DOCKET N0. 50-213
1.0 INTRODUCTION
By letter dated December 31, 1986, the Connecticut Yankee Atomic Power Company (CYAPC0) submitted a request for changes to the Haddam Neck Plant i
technical specifications.
This license amendment modifies Technical j
Specification 3.20, " Reactor Coolant System Flow, Temperature and Pressure,"
and Technical Specification Figure 2.2-2 to include revised three-loop i
operation safety limits and reactor coolant system (RCS) flow rate require-ments based upon the results of loop flow measurements conducted during the Cycle 14 (current cycle) startup.
By letter dated August 7, 1986, i
Connecticut Yankee Atumic Power Company (CYAPCo) has administratively l
prohibited three-loop operation at the Haddam Neck Plant until the revised safety limits, based on the lower measured loop flow rates, have been reviewed and approved.
2.0 EVALUATION The three-loop safety liraits were adjusted to account for a lower core flow rate.
The adjustment was based on sensitivities of the DNBR to changes in flow, pressure, temperature and power determined by the COBRA III-C model.
The adjustment was determined by calculating a lower l
core inlet temperature to compensate for a reduced core flow to maintain the same ONBR and core exit void fraction.
These results show that the allowed inlet temperature for 65% power and 2000 psia is reduced from 587.2 F to 581.2 F which is above the maximum inlet temperature value of 540.6 F allowed by the Technical Specifications.
1 The revised technical specification (TS) minimum vessel flow rate of j
197,200 gpm (188,300 gpm core flow) which is 3% less than the 202,520 gpm j
measured vessel flow was also evaluated for the impact on the three-loop safety analyses.
The lower flowrate value was used in the safety analyses and provides additional safety margin to the actual flowrate required for I
three-loop operation.
The current three-loop safety analyses was performed
{
l l
8707160760 070706 PDR ADOCK 05000M U p
' at a power level of 86% and an inlet temperature of 548 F.
Using DNBR sensi-tivities to core flow and power level, the licensee showed in letter dated June 9, 1987 that the reduction in DNBR due to flow reduction was 4%, while the increase in DNBR due to the difference in power level (86% analysis vs.
67% TS maximum allowed operating with errors) was 36%.
Therefore, the current three-loop safety analyses remains conservative.
The staff has reviewed the proposed change to Technical Specification 3.20 and Figure 2.2-2 and find them to be acceptable.
3.0 ENVIRONMENTAL CONSIDERATION
This amendment involves a change to requirements with respect to the installation or use of facility components 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 signi-ficant 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 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 10 CFR 51.22(o) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of this amendment.
4.0 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.
- 5. 0 ACKNOWLEDGEMENT Principal Contributor:
G. Schewnk, SRXB, NRR.
Dated: July 6,1987