ML20212C472
| ML20212C472 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 10/20/1997 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20212C461 | List: |
| References | |
| NUDOCS 9710290247 | |
| Download: ML20212C472 (3) | |
Text
.-
W s:09 p
i UNITED STATES
- r
}
NUCLEAR REGULATORY COMMISSION 2
WASHIHoToN, D.C. 20066 0001
'+,.....,o MFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NOS. 92 AND 79 TO FACitITY OPEDATING LICENSE N05. 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 DOCKET NCS. 50-428 AND 50-499 SOUTH TEXAS PROJECT. UNITSj AND 2
1.0 INTRODUCTION
By application dated August 14, 1997, as supplemented Septc.nber 23, 1997, Houston Lighting & Power Company, et.al., (the licensee) requested changes to the Technical Specifications (TS) (A90endix A to Facility Operating License Nos. NPF-76 and NFF-80) for the South lexas Project, Units 1 and 2 (STP).
The proposed changes would reduce the minimum required reactor coolant system (RCS) volume in TS 5.4.2, reflecting an increase in steam generator tube plugging.
The maximum required RCS volume remains unchanged.
The licensee's September 23, 1997, supplement provided responses to the staff's request for additional information dated September 4,1997, and did not chsnge the staff'_s initial no significant nazards determination.
2.0 BACKGROUND
in the August 14, 1997, submittal, the licensee noted that steam generator tube plugging has reduced the tctal water and steam volume of the STP, Unit 2 RCS below the range specified in TS 5.4.2.
The current TS 5.4.2 specifies the total water and ste n volume of the RCS is 13,814 i 100 cubic feet.
The licensee proposed to lower the specified minimum RCS volume to reflect the additio:tal steam generator tube plugging.
In the September 4, 1997, letter, the. licensee provided information regarding new licensing basis boron dilution analyses which were oerformed to justify the new proposed minimum RCS volume.
3.0 EVALUATION In its August 14, 1997, submittal, the licensee proposed to lower the specified minimum RCS volume in STP TS 5.4.2 from 13,"' cubic feet to 9710290247 971020 PDR-ADOCK 05000498 P
~.
- 13,364 cubic feet to reflect a maximum amount of 10% RCS steam generator tube plugging. The licensee indicated that the only licensing analyses affected by this TS change are those for boron dilution events.
The licensee's September 4, 1997, letter provided descriptions of boron dilution event analyses for the various modes of operation from full power to cold shutdown with the RCS not drained.
Fo,' Modes 1 and 2, in which the reactor is critical
-and reactor scram functions are available, the analyses indicate that a reactor trip occurs with accompanying alarm, and that, while the response time available is slightly reduced, the operator has more than 30 minutes to take action to terminate the dilution source.
This is greater than the 15 minutes specified in the staff's Standard Review Plan (SRP), NUREG-0800 guidance, and is therefore, acceptable.
For other modes in which the reactor is subcritical and the operator is alerted by a high flux alarm, the licensee has indicated that due to excess conservatism in the initial boron concentration for the previous analysis, the 1
15 minutes available i>r operator response calculated in the previous analysis continues to apply.
The 15 minute time available for operator response is consistent with SRP guidance and is therefore, acceptable.
Although not discussed in the licensee's submittals, for operation in modes l
with the reactor drained, it is apparent that the effective RCS coolant volume
[
is unchanged by the steam generator plugging assumption, and the boroa dilution analyses for these conditions are not affected.
Based on the results of the boron dilution analyses described in the licensee's September 23, 1997, submittal, the staff finds the proposed TS change to lower the specified minimum RCS volume from 13,714 cubic feet to 13.364 cubic feet acceptable.
4.0 STATE CONSULTATION
In accordance with the Commission'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
i The amendments change a requirement with respect to installation or use of a facility com,onent located within the restricted area as defined in 10 CFR Part 20. 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 Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding (62 FR 45278). 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.
O
, 16, 0 CONCLUSIOM The Commission has c,ncluded, based on the considerations discussed above, that:
(1) there it. 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 Commission's regulations, and (3) the issuance of the amendments will not be inimical.to the common 4
defense and securit, or to the health and safety of the public, Principal Contributor:
Frank Orr Date:- ictober 20, 1997 d
j
't e
T I
4