ML20078S888
| ML20078S888 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 02/13/1995 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20078S885 | List: |
| References | |
| NUDOCS 9502270374 | |
| Download: ML20078S888 (2) | |
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NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20086 4001 l
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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS 70 AND 59 TO FACILITY OPERATING LICENSE NOS. NPF-76 AND NPF-80 HOUSTON LIGHTING & POWER COMPANY CITY PUBLIC SERVICE BOARD OF SAN ANTONIO CENTRAL POWER AND LIGHT COMPANY CITY OF AUSTIN. TEXAS j
DOCKET NOS. 50-498 AND 50-499 SOUTH TEXAS PROJECT. UNITS 1 AND 2
1.0 INTRODUCTION
l By application dated November 8, 1994, Houston Lighting & Power Company, et.
al., (the licensee) requested changes to the Technical Specifications (TSs)
(Appendix A to Facility Operating License Nos. NPF-76 and NPF-80) for the South Texas Project, Units 1 and 2 (STP). The proposed changes would permit the substitution of an extended range neutron flux monitor for one of the source range neutron flux monitors during refueling operations.
i 2.0 DISCUSSION TS 3/4.9.2 governs the nuclear instrumentation required to be operable during refueling in Mode 6.
The current TS requires two source range neutron flux monitors to be operable to provide redundant capability to detect changes in core reactivity, each with continuous visual indication in the control room and one with audible indication in the containment and control room. This will alert operators to an increase in subcritical neutron multiplication due to a positive reactivity change.
In the event a source range detector were to become inoperable during refueling, it may be impractical to repair the detector without relief from the current TSs. Use of the extended range neutron flux monitors would allow orderly completion of core alterations such that a favorable configuration for detector repair could be achieved.
3.0 EVALUATION The extended range monitors provida reliable neutron flux measurement from reactor shutdown to full power. They have a range of 0.1 to 1.0E5 counts per second, and are capable of detecting changes in core reactivity during refueling operations. When neutronically coupled with a fuel assembly i
cluster, they provide a reliable indication of neutron flux equal to the 9502270374 950213 PDR ADOCK 05000498 P
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source range monitors. With the current TSs, one source range monitor must provide an audible indication in containment and in the control room, however, the second monitor is required to provide only a visual indication in the control room. This function could be satisfied by an extended range monitor, maintaining the required core monitoring capability and redundancy.
The licensee also requested changes to the related surveillance requirements to replace the analog channel operational tests with a channel calibration every 18 months.
The current analog channel operational test's are unnecessary since no trips are required during core alterations. The combination of the channel check and channel calibration are sufficient to ensure that the detectors are capable of monitoring core reactivity changes during Mode 6.
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Based on the above, the staff finds that the proposed changes are acceptable.
4.0 STATE CONSULTATION
In accordance with the Comission's regulations, the Texas State official was notified of the proposed issuance of the amendments. The State official had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
The amendments change a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and change surveillance requirements. The NRC staff has determined that the amendments involve 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 Comission has previously issued a proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding (59 FR 63124). 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 amendments.
6.0 CONCLUSION
The Comission 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, (2) such activities will be conducted in compliance with the Comission's regulations, and (3) the issuance of the amendments will not be inimical to the comon defense and security or to the health and safety of the public.
Principal Contributor:
T. Alexion Date: February 13, 1995 l