ELV-03723, Application for Amends to Licenses NPF-68 & NPF-81,modifying TS 3.7.1.6 Re Main Feedwater Isolation Sys to More Accurately Address Components That Form Primary Success Path for Mitigation of DBEs
| ML20113H618 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 07/31/1992 |
| From: | Mccoy C GEORGIA POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20113H620 | List: |
| References | |
| ELV-03723, ELV-3723, NUDOCS 9208050099 | |
| Download: ML20113H618 (6) | |
Text
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ve" "> w July 31, 1992 ELV-03723 Docket Nos.
50-424 50-425 U.
S. Iluclear Regulatory Commission ATTN:
Document Control Desk Washington, D.
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20555 Gentlement VOGTLE ELECTRIC GENERATING PLANT l
REQUEST TO REVISE TECHNICAL SPECIFICATIONS ADDITION OF FEEDHATER ISOLAT1011 SYSTELS In accordance with the provisions of 10 CFR 50.90 and 10 CPR 50.59, Georgia Power Company (GPC) hereby proposes to amenct the Vogtle Electric Generating Plant (VEGP)
Unit 1 ana Unit 2 Technical Specifications, Appendix A to Operating Licenses NPF-68 and NPF-81.
This amendment modifies the Technical Specifications by adding new specification 3.7.1.6, entitled Main Feedwater Isolation Systems.
This specification requirsa that the main feedwater isolation valves be operable.
This addition to the Technical Specifications is not a result of any change to the design or analyses.
The inclusion of this specification allows the Technical Specifications to more accurately address the co:nponents that form the priuary success path for mitigation of design basis events.
Georgia Power Company requests approval of this Technical Specification change by June 1, 1993.
The proposed changes and bases for the changes are described in onclosure 1 to this lettor. provides an evaluation pursuant to 10 CFR 50.92 showing that the proposed changes do not involve ~aignificant hazards considerations.
Instructions for incorporation of the proposed changes into the Technical Specifications and a copy of the proposed changes are provided in enclosure 3.
In accordance with 10 CFR 50.91, the designated state of ficial will be sent a copy of this letter and all enclosures.
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Georgia Power b U.
S. 11uclear Regulatory Commission I.'IN-0 3 7 2 3 Pago 2 Mr. C. K. McCoy states that he is a vico president of Georgia Power Company and is authorized to oxocute this oath on behalf of Georgia Power Company and that, to the best of his knowledge and belief, the facts not forth in this letter and enclosures are true.
GEORGIA POWER COMPANY By:
1 C. K. McCoy '
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Sworn to and subscribed before me this d/
ay of 1992.
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Enclosures:
1.
Basis for Proposed Change 2.
10 CFR 50.92 Evaluation 3.
Instructions for Incorporation and Revised Pages c(w):
ggntgla Power Cpjnpany Mr.
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B.
Shipman Mr. M. Shelbani 110RMS 11.__ S. 11uclear Regulatory Commission Mr.
S.
D.
Ebneter, Regional Administrator Mr.
D.
S.
liood, Licensing Project Manager, !!RR Mr.
B. R.
Bonsor, Senior Resident Inspector, Vogtle Etate of.31ggIgla
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Mr. J.
D.
Tanner, Commissioner, Dept. of 11atural Resources, r
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l EllCLOSURE 1 VOGTLE ELECTRIC GENERATING PLAllT REQUEST TO REVISE TECilNICAL SPECIFICATIONS J
ADDITISN OF PEEDWATER ILOLATION SYSTEMS DASIS FOR PROPOSED CNANE Proposed Change Tho proposed chango adds now specification 3/4.7.1.6, entitled Main Foodwater Isolation
- Systems, and associated bases.
The specification requires ti:at the main foodwater isolation and regulating valvos and their respectivo bypass valvos be operable or isolated when the reactor is in Modos 1 or 2.
Appropriato action statomonts and surveillanco requirements are included.
The exact text of the now specificchion is included with enclosuro 3.
Basis A main foodwater isolation valvo (MFIV) and an associated main foodwater isolation bypass valvo (BPIV) is provided for each of the foodwater linos to the four steam generators.
Eact. of these lines also contains a main foodwater regulating valvo (MFRV) and its associated main foodwater rogulating bypass valvo (DFRV).
The foodwater lino to each steam ganarator can bo isolated by the closure of either a MFIV or MFRV and its associated bypass valvo.
Those valvos provido redundant isolation for each main foodwater lino.
All of those valvos receive automatic loolation signals from both. trains -of -engincored snfoty features actuation syste m instrumentation as listed in table 3.3-2 of the Technical Specifications.
The safety-related function of the MPIVs and the MFRVs and thcir associated bypass valvos is to provide isolaticn for main feedwater flow to the cocondary side of -the steam generators.
The ovaluations of a foodwater malfunction, main steam lino break, feodwater lino break, small break-loss of coolant accident and steam gonorator tubo rupture take credit for isolating the foodwater lines.
The design basis for the isolation of the foodvater lines was established by the analysis of the main steam line break.
Failure to isolate the foodwater lines would result in additional foodwater to the steam generators that could result in additional cooling and additional unas and energy release.
Since thesc valvos are part of the primary success path for mitigation of a main steam line break, Georgia Power Company has determined that it is appropriate to include them in the Technical Specifications.
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-E!1 CLOSURE 1 (CollTIliUED)
VOGTLE ELECTRIC GEllERATING PLAllT REQUEST TO REVISE TECittlICAL SPECIFICATIO!iS ADDITIO!J OF FEEDWATER ISOLATI011 SYSTEMS BASIS FOR PROPOSED CllA!1GE The addition of this Technical Spoultication does not requiro design changes to the plant or any changes to the safoty analyses that are currently in placo.
The MFIVs and MFRVs (and their associated bypass valves) provido a redundant foodwater isolation capability.
The allowable times for operating with one of the isolation valve combinations inoperablo
_(and opon$ are consistent _with the allowable operating timos for operation with inoperable trains of redundant systems i
The survoillance requirements are not by testing in acccrdance with
-Soction XI of the ASME Codo.
The valvo oporation timo of 5 seconds is consistent with the response timo of 7 seconds recorded in table 10.3-2 of the-. Final Safety Analysis Report (PSAR),
since the responso time its this tablo includos an allowance of 2 seconds for l
cignal delay.
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l EllCIDSURE 2 VOGTLE ELECTRIC GEllERATIl1G PLAliT REQUEST TO REVISE TECH!i1 CAL SPECIFICATIOliS ltDDITIO!( OF FEEDWATER ISOLATIOli SYSTDiS 10 CFR 50.92.EVALUATIOli Pursuant to 10 CFR 50.92, Georgia Power Company has evaluated the proposed revision to the Technical Specifications and has determined that operation of the facility in accordance with the proposed amendment would not involve any significant hazards considerations.
D31CAUFEUld Automatic isolation of the foodwater system has always been a part of the VEGP design.
The addition of a Technical Specification for the main foodwater isolation system will provide asaurance that this system will be maintained operable in a manner consistent with its intended function.
Analysis Automatic isolation of the main feedwater system is provided when required to mitigate the consequences of a feedwater malfunction, main steam line break, foodwater line break, small break loss of coolant accident, or steam generator tube rupture.
The electro-hydraulle fail-closed main feedwater isolation valves and fail-closed air-operated bypass isolation valves close within C seconds on receipt of an engincored safety features (ESP) actuation signal.
Redundant safety grade feedwater line inclation is provided by the air-operated fail-c1caed main feedwater regulating and bypass regulating valves, which also close within 5 seconds on receipt of an ESP actuation signal.
Each valve receives a closure signal from both tralnn of the ESP actuation system.
These closure times are consistent with the values used in the transient and accident analyses densibed in chapter 15 of the FSAR.
The allowable operating time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> for operation with an inoperable isolation system is acceptable because the redundant isolation system is operable.
This time is consistent with the allowable operating time provided in Technical Specification 3.7.1.5 for an inoperable main steam line isolation system.
The proposed Teechnical Specification allows continued operation with an Anoperable isolation valvo, provided that the valve is closed.
This is acceptable because the safety function of the isolation valve is performed when it is closed.
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ENCLOSURE 2 (CO!1TINUED)
VOGTLE ELECTRIC GE11ERATING PLANT REQUEST TO REVISE TECHNICAL SPECIFICATIONS ADDITION OF FEEDWATER ISOLATION SYSTEMS 10 CFR 50.92 EVALUATION The specification allows the isolation system to be considered operable even if a valvo in the system is inoperablo, provided the valvo is closed.
It is understood that in Mode 1 a closed main foodwater isolation or main foodwater regulating valvo would not r1Iow full power operation because VEGP is not licensed for oporation with one loop isolated.
ConclusioD Based on the above consideration, GPC has concluded the following concerning 10 CFR 50.92.
1.
The proposed addition to the Technical Specifications does not involvo a
significant increase in the probability or consequences of an accident previously evaluated because it adds requirements to maintain the foodwater isolation systems in.a stato.that is consistent with the accidents previously analyzed.
2.
The proposed addition to the Technical Specifications does not croato the possibility of a new or different kind of accident from any accident provicualy evaluated because it requires the foodwater isolation system to be maintained operable in a manner that is consistent with the current accident analyses and does nat introduce any now or different operating requirements'for the foodwater isolation systems.
3.
The proposed a_ddition to the Technical Specifications does not involvo a significant reduction in a margin of safety because it will require the foodwater isolation system to perform in accordance with the assumptions used in the cafety analyses.
Thorofore, operation in accordance with the proposed specification will not_ affect any of the acceptanco limits or analysos used to demonstrate operation within the acceptance limits.-
Dased upon the preceding information, it has been determined that the propocod_Tuchnical Specifications addition _does not involve a-significant hazards consideration as defined by 10 CFR 50.92(c).
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