ML20246L107
| ML20246L107 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 05/08/1988 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20246L104 | List: |
| References | |
| NUDOCS 8905180237 | |
| Download: ML20246L107 (2) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION
'\\*..+lp WASHING TON, D. C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATICH RELATED TO AMENDMENT NO. 8 TO FACILITY OPERATING LICENSE NO. NPF-76 o
NOUSTON LIGHTING & POWER COMPANY CITY PUBLIC SERVICE BOARD OF SAN ANTONIO CENTRAL POWER AND LIGHT COMPANY CITY OF AUSTIN, TEXAS DOCKET NO. 50-498 SOUTH TEXAS PROJECT, UNIT 1
1.0 INTRODUCTION
By application dated February 24, 1986, Houston Lighting & Power Company, et. al., (HL&P or the licensee) requested changes to the plant and Final 56fety Analysis Report (FSAR) for South Texas Project, Unit 1.
The proposed change would modify thr. Engineered Safety Feature Actuation System (ESFAS) logic such that failure of the control room / electrical l
auxiliary building ventilation monitors, spent fuel pool monitors, and reactor containment building purge nonitors will be annunciated in the control room and only a high radiation signal would cause a heating, ventilation and air conditioning (HVAC) Engineered Safety Feature (ESF) actuation. The proposed change would reduce the number of unnecessary ESF actuations.
2.0 DISCUSSION l
This amendment is being issued pursuant to the requirements of 10 CFR 50.59(c) because HL&P identified the change as an unreviewed safety question. No change to the Technical Specifications is required by this amendment.
3.0 EVALUATION Currently, ESF actuation will occur automatically upon either failure of radiation monitor or a high radiation signal in either of two redundant monitors. These dual monitors, located in the control room / electrical auxiliary building, the spent fuel storage pool area and the reactor j
t,uilding purge line, are used to monitor the ventilation air steam.
In cach case, one monitor is assigned to safety train A, and the other l
train C.
Under the proposed change, the control room ESFs will still 6ctuate autocratically upon sensing a high radiation signal from either of the redundant monitors in each of the three areas, but autcmatic ESF actuation will not occur upon failure of a monitor. Monitor failure will be annunciated in the control room with three separate annunciators.
8905180237 890508 PDR ADOCK 05000498 P
PDC l
Technical Specification Table 3.3-3 specifies that the minimum number of radiation monitoring channels required to be operable for these three areas is two.
In the case of a monitor failure in the control room electrical auxiliary building area, a technical specification action statement requires that within one hour the control room envelope be isolated and the ventilation system be operated in the. filtered recirculation mode.
If a monitor failure occurs in the spent fuel pool area, fuel movement may proceed provided the fuel handling building (FHB) exhaust air filtration system is operated through at least one. train of high-efficiency particulate air (HEPA) filters and charcoal absorbers.
If a monitor failure occurs in the reactor containment building purge path, the containment purge supply and exhaust valves should be maintained closed. The licensee has comitted to provide operating procedures to address the technical specification action statements in response to the monitor failures. The technical specifications require automatic ESF actuation on a high radiation signal from any monitor.
Deletion of the monitor failure logic will not affect the reliability of this system to respond to a high radiation release, but will reduce the number of unnecessary ESF actuations.
Based on maintaining a one-out-of-two logic for radiation actuation, an action statement in the technical specifications requiring restoration of an inoperable system and the comitment to develop procedures to respond to monitor failures, the staff finds the modifications acceptable.
4.0 ENVIRONMENTAL CONSIDERATION
Pursuant to 10 CFR 51.21, 51.32 and 51.35, an environmental assessment and finding of no significant impact have been prepared and published in the Federal Recister on May 8, 1989 (54 FR 19618). Accordingly, based upcn the environmental assessment, the Comission has determincd that the issucoce of this amendnent will ret have a significant effect on the quality of the human environment.
5.0 CONCLUSION
Based upon its evaluation of the proposed changes to the South Texas Project, Unit 1, the staff has concluded that:
there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and such activities will be conducted in compliance with the Comission's regulations and the issuance of the amendment will not be inimical to the comon defense and security or to the health and safety of the public. The staff, the*, ore, concludes that the proposed changes are acceptable, and are hereby incorporated into the South Texas Project Final Safety Analysis Report.
Date:
May 8,1989 Principal Contributors:
C. Abbate H. Li
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