ML20238B397

Application for Amend to License NPF-68,revising Action Requirement for Inoperable Fuel Handling Bldg post-accident Ventilation Sys Actuation Instrumentation & Alarm/Trip Setpoint Limit for Chlorine Detection Sys.Fee Paid

ML20238B397
Person / Time
Site:	Vogtle
Issue date:	08/26/1987
From:	James O'Reilly GEORGIA POWER CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20238B400	List: ML20238B397 ML20238B410
References
SL-2603, NUDOCS 8709010202
Download: ML20238B397 (11)

Text

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. . Georgia Power Cornpany .

333 Psedmont Avenue i

. Manta, Georgm 30308 Telephone 404 526 7851

.l Ma4ng Address:

Post Ofhce Elox 4545 Atlanta, Georgia 30302 -

James P. O'Remy tre souttern ekxtrc !.ptem

' Genior Vice President

' Nuclear Operabons ~,

I SL-2603 0327m X7GJ17-V600 August 26, 1987

.l U. S. Nuclear Regulatory Commission ]

ATTN: Document Control Desk.  !

-Hashington, D.C. 20555 'l PLANT V0GTLE - UNIT 1 NRC DOCKET 50-424 OPERATING LICENSE NPF-68 REOUEST TO REVISE TECHNICAL SPECIFICATIONS 3.3.2. 3.3.3.7 -

Gentlemen:

In accordance with the provisions of 10 CFR 50.90 and .10 CFR 50.59, Georgia Power Company (GPC) hereby proposes changes to the Vogtle Electric.

Generating Plant Unit 1 Technical Specifications, Appendix A' to Operating License NPF-68. l The first proposed change revises the action requirement for inoperable '

Fuel Handling Building Post-Accident Ventilation System actuation  !'

instrumentation. The second proposed change revises the alarm / trip setpoint limit for the Chlorine Detection Systems which initiate operation . of the Control Room Emergency Filtration System in the isolation mode. l i

Enclosure 1 provides detailed descriptions of the proposed changes and the circumstances necessitating the change request. <

Enclosure 2 details the basis for our determination that the proposed changes do not involve significant hazards considerations.  ;

Enclosure 3 provides instructions for incorporating the proposed changes ,

L into the Technical Specifications. The proposed changed Technical  !

Specification p&ges follow Enclosure 3.  ;

Payment of filh fee is enclosed.

He request that the proposed amendment, once approved by the NRC, be issued with an allowable implementation period of 60 days.

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U. S. Nuclear Regulatory Commission August 26, 1987 Page Two Pursuant to the requirements of 10 CFR 50.91, Mr. J. L. Ledbetter of the Environmental Protection Division of the Georgia Department of Natural Resources will be sent a copy of this letter and all applicable enclosures.

Mr. James P. O'Reilly states that he is a Senior Vice President of Georgia Power Company and is authorized to execute this oath on behalf of Georgia Power Company, and that to the best of his knowledge and belief, the facts set forth in this letter are true.

Sincerely, GEORGIA POWER COMPANY by: cA w n .@ 4 Jases P. O'Reilly Sen4 r Vice President '

' SHORN 0 AND SUBSCRIEED BEFORE-1E

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THIS 26st DAY OF AUGUST 1987. J

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Notary Publi'c N0tsry $Uic. Georgia, Stds at Large My Commission Expires Sept.18,1987 JH/1m

Enclosures:

1. Bases for Proposed Changes

2. 10 CFR 50.92 Evaluation

3. Instructions for Incorporation

4. Check # 124680 for filing fee c: (see next page) 0327m

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U. S. Nuclear Regulatory Commission  ;

August 26, 1987 Page Three c: Georaia Power Comoany Mr. R. E. Conway Mr. J. P. O'Reilly Mr. G. Bockhold, Jr.

Mr. J. F. D'Amico .

Mr. C. H. Hayes l GO-NORMS )

Soltthern Company Services ,

Mr. R. A. Thomas 1

Mr. J. A. Bailey Shaw. Pittman. Potts & Trowbridge Mr. B. H. Churchill, Attorney-at-Law Troutman. Sanders. Lockerman & Ashmore '

Mr. A. H. Domby, Attorney-at-Law I

U. S. Nuclear Reaulatory Commission Dr. J. N. Grace, Regional Administrator Ms. M. A. Miller, Licensing Projec.t Manager, NRR (2 copies) <

Mr. J. F. Rogge, Senior Resident Inspector-0perations, Vogtle Georaians Aaqinst Nuclear Eneray Mr. D. Feig Ms. C. Stangler i

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ENCLOSURE 1-PLANT V0GTLE - UNIT 1 NRC DOCKET 50-424 OPERATING LICENSE NPF-68 REQUEST TO REVISE TECHNICAL SPECIFICATIONS 3.3.2, 3.3.3.7 DASES FOR PROPOSED CHANGES PROPOSED CHANGE 1 Revise the action requirement for Item 11 of Table 3.3-2 by . removing the reference to the 7 day' period and referring directly to Specification 3.9.12.

BASIS

, As currently worded, Action 26. for Item 11 of Table 3.3-2 implies that I

operation may continue for up to seven days with less than the required minimum channels of operable instrumentation before taking the action required  !

by Specification 3.9.12. This proposed change removes the reference to the

seven dey period and refers directly to Specification 3.9.12 for the action to i be taken on the basis of operability of the Fuel Handling Building Post-Accident Ventilation System.

[10 POSED CHANGE 2 Revise Specification 3.3.3.7 to raise the alarm / trip setpoint limit of the Chlorine Detection Systems from 2 ppm to 5 ppm.

BASIS Specification 3.3.3.7 currently requires an alarm / trip setpoint of less than or equal to 2 ppm. A new limit of 5 ppm is proposed. The .new limit-has been analyzed using methodology consistent with the current' plant licensing The analysis shows that the- time available for operators to don basis. i protective breathing apparatus is reduced slightly but is adequate and is well above NRC guidelines. The 5 ppm limit is proposed to reduce spurious control room isolations which have occurred as a result of erratic detector-sensitivity at a 2 ppm setpoint.

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ENCLOSURE 2 PLANT,V0GTLE'- UNIT 1 NRC DOCKET 50-424 OPERATING LICENSE-NPF-68 REQUEST TO REVISE TECHNICAL SPECIFICATIONS 3.3.2, 3.3.3.7 )

10 CFR 50.92 EVALUATION I

Pursuant to 10 CFR 50.92, Georgia Power Company has evaluated the attached proposed amendment to the VEGP Unit 1 Technical . Specifications and has 'f determined that operation of the facility in accordance with the proposed  !

amendment would not involve significant hazards considerations. The basis for I the determination is as follows: q PROPOSED CHANGE 1 Revise the action requirement for Item 11 of Table 3.3-2 by removing the i reference to the 7 day period and referring directly to Specification 3.9.12.

BACKGROUNQ Items lla, b, and c of Table 3.3-2 apply to the Fuel Handling Building j Post-Accident Ventilation Actuation Instrumentation. This table lists l operability requirements and actions to be taken in the event of inoperable instrumentation channels. In addition, the Fuel Handling Building Post-Accident Ventilation System operability requirements are given in Specification 3/4.9.12. Specification 3.9.12 includes the actions to be taken in the event one or both trains of the Fuel Handling Building Post-Accident i Ventilation System become inoperable.  !

The current action statement for instrument channel inoperability states i that the action of Specification 3.9.12 shall be taken within 7 days if the  !

number of operable channels is less than the minimum channels operable requirement. This implies that the actions of Specification 3.9.12 could be delayed for 7 days if the failure of instrumentation channels resulted in one or both trains of the Fuel Handling Building Post-Accident Ventilation System oming inoperable.

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The proposed change deletes the 7 day allowance and provides a - direct reference to Specification 3.9.12 for determination of the appropriate action for inoperable instrumentation channels on the basis of the effect on the operability of the system. It is noted that no ' credit is taken for this system in the safety analyses.

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4 ENCLOSURE 2 (Continued) 10 CFR 50.92 EVALUATION ANALYS15 GPC has reviewed the proposed change .to the action requirement for Fuel Handling Building Post-Accident Ventilation Actuation Instrumentation and has  ;

determined that the change does _not involve significant hazards considerations. In support of this conclusion the following analysis is provided:

1. The proposed change does not significantly increase the probability or consequences of an accident previously evaluated.- The change has no effect on the operation of the Fuel Handling Building ' Post-Accident Ventilation System. The change achieves consistency within the Technical Specifications and ensures that no delay occurs in execution -of action requirements for inoperable instrument channels. Furthermore, operation of the Fuel Handling Building Post-Accident Ventilation System is not assumed in any accident evaluated for Plant Vogtle.

2. The proposed change does not create the possibility of a new or d.ifferent kind of accident than any accident previously evaluated. The change does not affect the design or operation of the Fuel Handling Building Post-Accident Ventilation System or any other plant system or structure.

No new mode of failure is introduced by the change, therefore, a new or different kind of accident could not result.

3. The proposed change does not significantly reduce a margin of safety. The fuel Handling Building Post-Accident Ventilation System is not ~ assumed to operate in any accident analyzed for Plant Vogtle. The system provides defense in depth to minimize the radiological consequences of a fuel handling accident. The change does not reduce the capability of the system to perform this function. The change should reduce the likelihood that a misinterpretation of the Technical Specifications will prolong an inoperable condition.

C0KCWS10E Based on the preceding analysis, GPC has determined that the proposed change to the Technical Specifications will not significantly increase the probability or consequences of an accident previously evaluated, create the possibility of a new or different kind of accident from any: accident previously evaluated, or involve a significant reduction in a margin of safety. GPC therefore concludes that the proposed change meets the requirements of 10 CFR 50.92(c) and does not involve significant hazards considerations.

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ENCLOSURE 2 (Continued)  ;

10 CFR 50.92 EVALUATION i

PROPOSED CHANGE 2 Revise Specification 3.3.3.7 to raise the alarm / trip setpoint limit of the ,

Chlorine Detection Systems from 2 ppm to 5 ppm. 1 BACKGROUND The subject chlorine detection systems automatically initiate operation of the Control Room Emergency Filtration System in the isolation mode. GPC has experienced numerous control room isolations from these chlorine detectors as discussed in Licensee Event Reports 50-424/1987-019 (5/29/87) and 50-424/1987-028 (6/26/87). Manual air sampling- and analysis following the events produced no indication of chlorine gas. GPC believes that a major contributor to these isolations was erratic sensitivity of the chlorine detectors at the current 2 ppm setpoint. The vendor-recommended setpoint is i

i 50% to 70% of the full scale reading of 10 ppm. GPC is proposing a 5 ppm I setpoint to improve the reliability of the detectors and reduce unnecessary operation of the Control Room Emergency Filtration System.

The current 2 ppm setpoint is based on an analytical evaluation of con'rol room habitability in the event of a 1 ton chlorine cylinder rupture at the Nuclear Service Cooling Hater chlorine storage building. This evaluation was submitted to the NRC in References 1 and 2 and was reviewed and accepted by NRC as discussed in Reference 3.

GPC has evaluated an increase in the ch10rine detector setpoint using methodology consistent with that described in the references. This analysis utilized the Regulatory Guide 1.95 meteorological model and control room infiltration model previously used and accepted by NRC. The VEGP design basis .

wind speed of 0.9 m/s, which represents the worst fifth percentile wind i velocity, and Pasquill Class F stability were assumed. Calculations were also '

performed using a wind speed of 0.7 m/s to show the sensitivity of the l analysis to changes in wind speed.

The results of the analysis show that a setpoint of 5 ppm is acceptable.

At this setpoint, approximately 9 minutes,13 seconds are avcilable to the operator to , don protective breathing apparatus (7 minutes, 29 seconds at 0,7 m/s wind speed) after a chlorine alarm is received. This represents only a 12% reduction in available time as compared to the original analysis and is well above the 2 minutes in which VEGP operators are trained to don breathing equipment after detecting toxic gas. This is also well above the 2 minute guideline contained in Regulatory Guides 1.78 and 1.95 and is consistent with the 5 ppm guideline contained in Regulatory Guide 1.95.

0327m E2-3 08/26/87 SL-2603

ENCLOSURE 2 (Continued) 10 CFR 50.92 EVALUATION It is noted that the original analysis did not consider ,

chlorine-contaminated air entering directly into the control room through ' the {

normal HVAC system outside air intakes. This assumption was valid since, at a '

setpoint of 2 ppm, the control room isolation dampers would be closed before any contaminated air could travel from the detector to. the downstream isolation damper. Chlorine concentrations were calculated by assuming that  !

750 cfm of contaminated air entered the control room through various 1.eakage i paths specified in Reference 2.

In evaluating the effects of higher detector setpoints, where 'the time f required to close the isolation dampers exceeded the time required for contaminated air to reach the downstream damper, the analysis accounted for 3000 cfm of chlorine-contaminated air entering the control room through the 1 normal HVAC system outside air intakes until the isoittion dampers were fully i l closed. All other aspects of the original analysis, including the model, remained unchanged.

ANALYSIS l GPC has reviewed the proposed chlorine monitor setpoint change with I respect to the requirements of 10 CFR 50.92 and has determined that the change does not involve significant hazards considerations.

In support of this  !

conclusion, the following analysis is provided:

1. The proposed change will not significantly increase the probability or consequences of an accident previously evaluated. The change affects only the chlorine concentration at which operation of the Control Room Emergency Filtration System is automatically initiated in the isolation mode. Operation of the filtration system in_ response to a safety injection, high radiation, or manuel initiation signal is not affected. i i

' Initiation of the filtration system at the revised chlorine setpoint maintains the required level of protection for control room operators during an accidental chlorine gas release. An analysis using methodology consistent with the current plant licensing basis shows that the time ,

available to operators to don protective breathing apparatus is well above trained operator response time and NRC minimum guidelines.

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ENCLOSURE 2 (Continued) 10 CFR 50.92 EVALUATION

2. _The proposed change does not create the. possibility of a new or different I kind of accident than any accident previously evaluated. The change does l not modify the design of the Chlorine Detection Systems, 'the Control Room i

Emergency Filtration System, or any .other plant system or structure.

Since no new system configuration or failure mode would result from the J change, a new or different kind of accident could not result.

3. The proposed change does not significantly reduce a margin of safety. '

Protection of control room operators in _the event of. an accidental chlorine gas release is maintained well above NRC _ minimum criteria. GPC j believes that the chlorine detectors will operate more reliably at the revised setpoint and that degradation of the Control Room Emergency Filtration System from unnecessary operation will be reduced, making a positive contribution to margins of safety.

CONCLUSION i Based on the preceding analysis, GPC has determined ' that the proposed i change to the Technical Specifications will not significantly increase the '

probability or consequences of an accident previously evaluated, create the possibility of a new or different kind of accident from any accident previously evaluated, or involve a significant reduction in a margin of safety. GPC therefore concludes that the proposed change meets the requirements of 10 CFR 50.92(c) and does not involve significant hazards j considerations.  !

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ENCLOSURE 2 (Continued) 10 CFR 50.92 EVALUATION REFERENCES

1. GPC letter to NRC dated November 26, 1985, Log GN-750 l 2. GPC letter to NRC dated February 19, 1986, Log GN-808

3. -NUREG-1137 Supplement 2, " Safety Evaluation Report Related to the Operation of Vogtle Electric Generating Plant Units 1 and'2.

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1 ENCLOSURE 3 .

1 PLANT V0GTLE - UNIT 1 NRC DOCKET 50-424 OPERATING LICENSE NPF-68

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REQUEST TO REVISE TECHNICAL SPECIFICATIONS 3.3.?, 3.3.3.7 INSTRUCTIONS FOR INCORPORATION i

The proposed change to the Technical Specifications (Appendix A to 1 Operating License NPF-68) would be incorporated as follows:

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Femove Page Insert Page 3/4 3-24 3/4 3-24 3/4 3-25 3/4 3-25 3/4 3-27 3/4 3-27 3/4 3-63 3/4 3-63 l

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