ML20236K637
| ML20236K637 | |
| Person / Time | |
|---|---|
| Site: | Waterford  |
| Issue date: | 07/02/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20236K636 | List: |
| References | |
| NUDOCS 9807100019 | |
| Download: ML20236K637 (3) | |
Text
F
@ Kito p
t UNITED STATES
~
y j
NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20656-0001
.....l SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO 143 TO l
FACILITY OPERATING LICENSE NO. NPF-38 l
ENTERGY OPERATIONS. INC.
WATERFORD STEAM ELECTRIC STATION. UNIT 3 DOCKET NO. 50-382
1.0 INTRODUCTION
By application dated June 3,1997, as supplemented by letter dated May 1,1998, Entergy Operations, Inc. (the licensee), submitted a request for changes to the Waterford Steam Electric Station, Unit 3, Technical Specifications (TSs). The requested changes would change the action requirements for TS 3/4.3.2 for the Safety injection System Sump Recirculation Actuation Signal (RAS). It would revise the allowed outage time for a channel of RAS to be in the tripped condition from " prior to entry into the applicable MODE (S) following the next COLD SHUTDOWN" to the more restrictive time limit of 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, and add a shutdown requirement. Additionally, the i
TS 3.0.4 exemption would be removed from the action for the tripped condition. A proposed l
change to TS Bases Section 3/4.3.2 was also included.
The May 1,1998, letter provided clarifying information that did not change the initial proposed no significant hazards consideration determination.
I
2.0 BACKGROUND
The licensee's' application states that the Safety injection System Sump RAS is initiated by a 2 out of 4 logic for the Refueling Water Storage Pool (RWSP) low signal. If this occurs in conjunction with a containment spray actuation signal or a safety injection actuation signal, the RAS system will change the mode of operation of the Containment Spray (CS) System and the l
Safety injection System. The RAS automatically stops the Low Pressure Safety injection (LPSI) pumps and changes the CS and High Pressure Safety injection (HPSI) pump suction from the RWSP to the Safety injection System Sump. The RAS is designed to automatically realign the CS and HPSI systems for long-term operation following a Design Basis Accident by diverting the suction of these pumps from the RWSP to the Safety injection System Sump, when the contents of the RWSP are nearing depletion.
The postulated condition could occur when one channel of the RAS is in the " tripped" condition l
and a loss-of-coolant accident or excess steam demand event occurs. in these scenarios, prior j
to the RWSP reaching the low level setpoint, a failure occurs such that a second channel produces a low level trip signal. If this were to occur prior to there being adequate water in the Safety injection System Sump from the reactor coolant system leak and containment spray, the HPSI and CS pumps would have their suctions supplied by an inadequate source of water and the LPSI pumps would stop. Although the RWSP outlet valves would rnain open, the l
9807100019 980702 r~~
j PDR ADOCK 05000382 P
PDR w_______________
l
. containment pressure would rise above RWSP outlet pressure, which would cause the RWSP I
outlet check valves to seat. In effect, this would allow a single failure (the failure of the second 1
channel of RAS in the tripped condition) to remove both trains of HPSI, LPSI, and CS from service.
3.0 EVALUATION The proposed change will revise the allowed outage time for a channel of Safety injection i
System Sump RAS to be in the tripped condition from " prior to entry into the applicable MODE (S) following the next COLD SHUTDOWN" to the more restrictive time limit of 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, and add a shutdown requirement if the tripped channel is not retumed to operable status in 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> or is not placed in the bypass condition. This change is acceptable because it is more restrictive.
The current TSs allow continued operation until the next cold shutdown. If a failure occurred at the start of an operating cycle, a channel could be in the trioped condition for up to a maximum of about 18 months. The proposed TSs allow continued operation for only 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />.
The more restrictive time of 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> is desirable because it limits the time that the plant is l
vulnerable to a design basis accident combined with a single failure (in a second channel of '
RAS) that has the potential to remove both trains of HPSI, LPSI and CS from service. More specifically, for a premature RAS to occur during the 48-hour allowed outage time, the single failure would have to occur precisely during the injection phase of a loss-of-coolant accident or main steam line break (an unlikely scenario). In addition, the licensee has indicated that the 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> will provide a reasonable amount of time for repair of a failed channel, which the staff finds acceptable. Based on the above, the staff accepts the 48-hour allowed outage time.
The proposed change will also revise the allowed outage time that two RAS channels are inoperable (provided one channel is tripped and the other is bypassed) from "until performance of the next required CHANNEL FUNCTIONAL TEST," which could be up to a maximum of three months, to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />. This change is acceptable because it is also more restrictive. The more restrictive time is desirable for the same vulnerability discussed above for one channel inoperable and in the tripped condition.
The TS 3.0.4 exemption, which allows entry into an operational mode when the limiting condition for operation is not met, is being removed for the condition of a tripped channel. This is acceptable because there is now a specific allowed outage time for a tripped channel. This change is also more restrictive.
The licensee's May 1,1998, supplement provided clarifying information and revised the proposed TSs. The June 3,1997, initial application attempted to divide the TS action statements based upon whether an inoperable channel was placed in the bypassed or tripped condition. The May 1,1998, supplement divides the TS action statements based upon how many channels are inoperable. The staff has reviewed the TSs proposed in the May 1,1998, supplement and agrees that the revised wording clarifies end improves the proposed TSs.
l The licensee has also proposed changes to the related Bases section. The staff has reviewed l
the proposed Bases and finds that they are consistent with the changes to the TSs described above, and are therefore, acceptable.
r-q l
4 3
4.0 STATE CONSULTATION
in accordance with the Commission's regulations, the Louisiana State official was notified of the proposed issuance of the amendment. The State official had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendment involves 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 Commissicn has previously issued a proposed finding that the amendment involves no si0nificant hazards consideration and there has been no public comment on such finding (62 FR 33124). Accordingly, the amendment meets the eligib,lity 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 amendment.
6.0 CONCLUSION
The Commission 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 Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
l-Principal Contributor. T. Alexion Date: July 2, 1998 I-1