ML20114B720
| ML20114B720 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 08/20/1992 |
| From: | NRC |
| To: | |
| Shared Package | |
| ML20114B709 | List: |
| References | |
| NUDOCS 9208310137 | |
| Download: ML20114B720 (3) | |
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SAFETY E'AVATION BY THE OFFICE OFRCLEAR REACTOR REGULELM f1 LATED TO AMEND"ENT NO. 53 TO F.ACILITY OPERATING LICENSE NPF-68 AND AMENDMENT NO. 32 TO FACILI.TY OPERATING LICENSE NPF-81 GEORGI A POWER COMPANY. ET AL V0GTLE 8;LtCTRIC GENERATING. PLANT. UNITS 1 AND 2 p'j DOCKET NOS. 50-424 AND 50-425 w
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INTRODUCTION
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'y Ietter dated May 3,1991, as sunplemented August l', and October 11, 1991,
'J1y 20, 1992, Georgia h,wer Company, et al. (the scensee) proposed se amendments to change the 'echnical Specifications (TS) for the Vogtle eic Generating Plant (Vogtle or the facility), Units 1 and 2.
The 4,
sed change would add e footnote to TS 3.6.3, " Containment Isolatim 3
n
- ,es, " to sta'.e that " Isolation valves associated with the cortainment
-drogen monitors may be opened on an intermittent basis under ;dministrative
' ol " The proposed footnote would apply while the plant is in Modes I ugh 4.
The proposed cMnge wou'd also supplement associateo TS Basis 3,
.6.3 " Containment 1 solation Valves" to s+ + that "The containment
, tion vr.lves associatt i with t" -
aydrogen monitors may be T
c..
d on an intermittent tcsis u-ative control.
Silice the ct. Jols for these valves art Ic in control room, which is d
continuously manned, an operator able to ensure y apid isolation if necessary."
The licensee's sup,,lemental submittals dated Augud 39 ar.d October 11, 1991,
' Jn'.y 20, 1992, provided additional informaston te <aoport the original request and did not change the NRT.'s proposed no.;'.gnificant hazards considerat ' c c. R 'nination.
64 EVALUA'sA if TS 3.6.3 re/Jires that the containment isolation valves (CIVs) be operable ir Modes 1 through 4.
Tne associated action statement requires, in part, that with one or more of the CIVs inoperable, at least one isolation valve is to be maintained operable in each affected penetration that is open. TS 4.6.4.1 requires that each hydrogen monitor (Al-12979, Al-12980) be demonstrated operable by periodically performing channel chucks, analog channel operational tests, and channel calibrations using sample gas of specified composition. The opening of the C1/s related to the containment hydregen monitors to perform the surveillance requirements of TS 4.6.4.1 has the advantage of allowing verification of the flow path as well as the flow rate delivere< by the hydrogen monitor pump.
9208310137 920820 PDR ADOCK 05000424 P
PDR The licensee also notes that testing of the post-accident sampling system (PASS) with respect to sampling the containment atmosphere requires that these valves be opened.
l The CIVs for the hydrogen monitoring system are normally-closed, remote-manual l
valves that do not receive an automatic closure signal to cause containment isolation. The hydrogen monitoring system is a Seismic Category 1 system.
l All piping and valves in the system have been qualified as ASME Section III, Class 2.
This system is designed to retain its integrity and operability under all conditions following a design basis accident.
The system has also demonstrated the capability of withstanding the post-accident environment inside containment.
Relevant portions of PASS are also designed to Seismic Category I requirements and will function under post-accident conditions.
The licensee's intent is to open these valves under administrative control for the purpose of surveillance testing or sampling the containment atmosphere.
In its lette-of July 20, 1992, the licensee indicates that the CIVs would be closed in the event that it becomes necessary to dis-
'nue an operation for which the valves were opened.
Specifically, the licensee states "In the event that an operation for which the valves were opened canot be completed, the applicable procedures will contain a cautionary note to ensure that the subject valves are closed." The NRC staff finds, therefore, th:,t opening of the CIVs while the plant is in Modes 1 through 4 will occur only on an intermittent basis and only for the duration needed to accomplish the surveillance.
I During the review of the licensee's application, the NRC staff requested the licensee to discuss the method of closing these valves promptly if required.
The licensee first responded by letter dated August 19, 1991, which proposed to supplement associated TS Basis 3/4.6.3 as quoted above in the Introduction l
of this safety evaluation. The response notes that since the controls for l
these valves are located in the main control room, an operator would be I
available to close these valves rapidly if required.
In its subsequent response on October 11, 1991, the licensee clarified the proc
- dural controls which would direct the operator to close the subject valves and t.ie approximate time in the sequence of events at which closure of the valves would be expected to occur. The correspondence revealed that the subject valves are equipped with position indication in the monitor light boxes on the main control beard.
Upon a containment isolation signal while in Modes 1 I
through 4, the operator would be directed to verify that the CIVs are in their corret state.
If the valves failed to close as shown by the light box indication, the operator would then be instructed to close them.
Whea an event is coincident with a safety injection actuation, step 6 of t h licensee's procedure 19000-C, "E-0 Reactor Trip or Safety Injection," requires i
the operator to verify that the monitor light box indications are cor".ct for l
an injection phase after load sequencing.
This verification would b< made during t.% initial moments of the event.
If an abnormal condition occurs, the operator.. auld follow procedure 18004-C, " Reactor Coolant System Leakage."
This procedure would either direct the operator to enter procedure 19000-C or, depending on plant conditions, establish containment integrity by initiating a containment isolation, ensuring that all manual conta ument isolation valves are closed, and initiating closure of the containment equipment and personnel
hatches. These CIVs are designed to operate during an event when the maximum differential pressure is 80 psid or less. The staff finds that the actions given in the procedure ensure that these CIVs would be closed within a few minutes of identification of the need for containment isolation.
Based on the above, the NRC staff has reasona' ale assurance that, if wened while the plant is in Modes 1 through 4, the CIVs for the containment hydrogen monitoring system will be under the operator's cognizance and control and will be closed if not needed to be open or if required to be closed due to an abnormal event. Therefore, the proposed change is acceptable. 'The staff also finds the revision to TS Basis 3.6.3 to be consistent with the new footnote and the licensee's procedures and, therefore, to be acceptable.
3.0 STATE CONSULTATION
In accordance with the Commission's regulations, tne Georgia State official was notified of the proposed issuance of the amendments.
The State official had no comments.
4.0 LNVIRONMENTAL CONSIDERATION Ti m amendments change a requirement with respect to the installation or use of tacility components 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 a a nts, and no significant change in the types, of any effluents that may be released offsite ar.d that there is no significant i
increase 11 individual or cumulative occupational exposure.
The Commission has previot. sly issued a proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding (56 FR 29277 dated June 26, 1991).
Accordingly, the amendments meet 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 these amendments.
5.0 CONCLUSION
The Commission has concit.ded, based on the considerations discussed above, that:
(1) there is reasanable assurance that the health and safety of the public will not be ende.gered by operation in the proposed manner, (2) such I
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 defense and security or to the health and safety-of the public.
Principal Contributors:
D. Hood, PDII-3/0RP-I/II l
K. Bristow, SPLB/ DST Dated: August 20, 1992
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