ULNRC-03151, Application for Amend to License NPF-30,revising TS 4.6.1.7.4 & Associated Bases Re Containment Ventilation Sys

Application for Amend to License NPF-30,revising TS 4.6.1.7.4 & Associated Bases Re Containment Ventilation Sys

ML20080Q618
Person / Time
Site:	Callaway
Issue date:	02/24/1995
From:	Schnell D UNION ELECTRIC CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20080Q621	List: ML20080Q622 ULNRC-03151, Application for Amend to License NPF-30,revising TS 4.6.1.7.4 & Associated Bases Re Containment Ventilation Sys
References
ULNRC-03151, ULNRC-3151, NUDOCS 9503080433
Download: ML20080Q618 (10)

Text

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Y i' - 1901 Choutecu Avenue

, ,, Post Othce Box 149

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. St. Louis. Missouri 63166

. < 314-554-2650 ' t b .  !

i DonaldF.Schnell NION sernor vice eresisent TRIC Nuclear -

h5 February 24, 1995 l

U.S. Nuclear Regulatory Commission Attn: Document Control Desk ,

Mail Station P1-137 Washington, D.C. 20555 ULNRC-03151 Gentlemen:

DOCKET NUMBER 50-483 CALLAWAY PLANT REVISION TO TECHNICAL SPECIFICATION 4.6.1.7.4 CONTAINMENT VENTILATION SYSTEM i i

Union Electric Company herewith transmits an application for amendment to; Facility Operating License No. NPF-30 for Callaway Plant.

This amendment application proposes revising i Technical Specification Surveillance Requirement j 4.6.1.7.4 and its associated Bases to delete the i requirement to verify quarterly that the measured l I

leakage rate is less than 0.05 times the maximum-allowable leakage rate for each 18-inch containment mini-purge supply and exhaust isolation valve. This l requirement would be replaced with a quarterly l requirement to demonstrate operability by verifying l that when the measured leakage rate for these valves is i added to the leakage rates determined pursuant to i Specification 4.6.1.2d for all other Type B and C  !

penetrations, the combined leakage rate is less than 0.60 times the maximum allowable leakage rate.

Attachments 1, 2, 3, and 4 contain the Safety Evaluation, the Significant Hazards Evaluation, the l Environmental Consideration, and the Proposed Technical i Specification Changes in support of this amendment nn- . , .

9503090433 950224

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PDR ADOCK 05000483 PDR P

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U.S. NuclCOr R gulctory -Conniccion ,

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<- request. This. change request has been' approved by the Callaway Onsite Review Committee and the Nuclear' Safety  ;

Review Board. l If.you have any questions concerning this matter,  !

please contact me. .,

l Very truly yours,  ?

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Donald F. Schnell l JMC/ dis Attachments: 1) Safety Evaluation l

2) Significant Hazards Evaluation  ;

3) Environmental Consideration ,

4) Proposed Technical Specification Changes i

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STATE OF MISSOURI. )

)- SS CITY OF ST. LOUIS )

. Donald F. Schnell, of lawful age, being first duly sworn upon oath says that he is Senior Vice President-Nuclear and

- an officer of Union Electric Company; that he has read.the foregoing document _and knows the content thereof; that he has executed the same for and on. behalf of-said company with full power and authority to do'so; and that.the facts therein stated are true and correct to the best of his knowledge, information and belief.

By Donald-F. Schnell Senior Vice President Nuclear SUBSCRIBED and sworn to before me this c8N day of Muw/- , 1995.

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BARBA[A i PkFE NOTARY PUBLIC-STATE OF MISSOURI MT COMMISSJON EXPlRES APRIL 22,1993 ST. LOUIS COUNU

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i cc: .T. A. Baxter, Esq. i Shaw, Pittman, Potts &_Trowbridge 2300 N. Street, N.W.

Washington, D.C. 20037 M. . H. Fletcher 3 Professional Nuclear Consulting, Inc. '

18225-A Flower Hill Way Gaithersburg,-MD 20879-5334 L. Robert Greger

, Chief, Reactor Project Branch 1 U.S. Nuclear Regulatory Commission i Region III "

801 Warrenville Road Lisle, IL 60532-4351 Bruce Bartlett &

Callaway Resident Office  !

i U.S. Regulatory Commission RR#1 Steedman, MO 65077 ,

L. R. Wharton (2)  ;

office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission ,

1 White Flint, North, Mail Stop 13E21 11555 Rockville Pike 'i' Rockville, MD 20852-2738 Manager, Electric Department  !

Missouri Public Service Commission P.O. Box 360 i Jefferson City, MO 65102 ,

Ron Kucera r Department of Natural Resources l P.O. Box 176 i Jefferson City, MO 65102  :

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s Attachment 1

. . Paga 1 of 3 ULNRC4 3151 SAFETY EVALUATION Pronosed Chance This amendment request revises Technical Specification (T/S)

Surveillance Request 4.6.1.7.4 and its associated Bases to delete the requirement to verify quarterly that the measured leakage rate is less than 0.05 times the maximum allowable leakage rate ( L, ) ,

for each 18-inch containment mini-purge supply and exhaust isolation valve. This requirement would be replaced with a quarterly requirement to demonstrate operability by verifying that when the measured leakage rate for these valves is added to the leakage rates determined pursuant to Specification 4.6.1.2d for all other Type B and C penetrations, the combined leakage rate is less than 0.60 L,.

Backaround The containment mini-purge supply and exhaust isolation valves are 18-inch damper type valves that are pneumatically operated. These valves are automatic valves that close on receipt of a Containment Purge Isolation Signal (CPIS). They have a resilient seal for proper valve seating and are required to close in less than 5 seconds to provide containment isolation.

During power generation operation the mini-purge system is ]

designed to minimize occupational exposures to '

as-low-as-reasonably-achievable (ALARA) levels. Instead of i personnel entering the containment with airborne activities much l greater than the maximum permissible concentration, the l containment will be purged to reduce airborne radioactivity l concentrations and exposures in line with the philosophy of 10 CPR 20 and Regulatory Guide 8.15. The mini-purge system is designed to be operated continuously to achieve these objectives. l The need for continuous operation includes consideration for planned and unplanned entries into the containment and the need to periodically vent excess air from the containment to maintain the pressure near atmospheric conditions. The mini-purge system is manually initiated from the control room. Exhaust from the containment is processed through the containment purge exhaust system charcoal adsorption train prior to being discharged through the unit vent. The containment purge exhaust system is monitored for radioactivity, both upstream and downstream of the charcoal adsorber.

During emergency operation, both the containment shutdown purge and the containment mini-purge isolation valves are automatically closed upon receipt of a CPIS. The CPIS is initiated by receipt of a safety injection signal or by high radioactivity levels in the purge exhaust radiation monitors. The containment purge isolation valves are designed for rapid closure to minimize release of containment effluents following postulated accident conditions. The containment mini-purge isolation valves are designed for tight closure within 5 seconds after receipt of an isolation signal.

. Attcchment 1

• Pega 2 of 3  ;

ULNRC-03151 Evaluation The containment mini-purge isolation valves are used to provide-containment integrity during normal and emergency operations. ,

Removal of the individual leakage rate acceptance criteria for j these valves will not affect the consequences of an accident since  !

the overall Type B and C containment leakage rate will be maintained less than the 10 CFR 50 Appendix J acceptance criterion i of 0.60 L, .

l The primary functions that the mini-purge valves provide are  !

closure in 5 seconds upon receipt of a CPIS and to seal tightly I such that the overall Type B and C containment leakage rate l remains below 0.60 L, . The deletion of the individual leakage l rate acceptance criterion for these valves will not affect their closure stroke time, nor will it impact the ability to detect  ;

early valve seal degradation to prevent seal failures. These valves will still be required to undergo quarterly testing for leakage rate which will be used as the mechanism for seal degradation detection. Instead of an individual acceptance I criteria, their leakage rate will be added to the combined leakage rate for all Type B and C penetrations.

The current T/S surveillance requirement is not contained in NUREG-1431, " Standard Technical Specifications-Westinghouse Plants." It allows the use of acceptance criteria in accordance with 10 CFR 50, Appendix J, which would be the Type B and C combined leakage rate of less than 0.60 L, . The NUREG-1431 Bases for this surveillance indicates the testing frequency for these ,

valves is based on operating experience. The type of seal used is more susceptible to degradation in a shorter time period than other seal types. The purpose of this surveillance is to ensure that the seals are not deteriorating to a point where they would fail and compromise containment integrity, and that excessive containment purge valve leakage is properly accounted for in determining the overall containment leakage rate.

The proposed revision to T/S Surveillance Requirement 4.6.1.7.4 and its associated Bases to delete the requirement to verify quarterly that the individual measured leakage rate for each 18-inch containment mini-purge supply and exhaust isolation valve is less than 0.05 times the maximum allowable leakage rate is consistent with the guidance provided in NUREG-1431. The proposed revision does not involve an unreviewed safety question because operation of Callaway Plant with this change would not:

a) Increase the probability of occurrence or the consequences of an accident or malfunction of equipment important to safety previously evaluated in the Safety Analysis Report. The proposed revision to the T/S will not adversely impact plant safety since the requirement to perform the quarterly surveillance will still be implemented to verify valve leakage and seal degradation.

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, ULNRC- 03151 .; i q

? b) Create'the possibilityLfor anLaccident or malfunction of . . i equipment of aidifferent type.than any.previously evaluated- .i Lin'the-Safety; Analysis Report. :There are no-designichanges i being made'that would-create the possibility for an' accident r

- or malfunction _of equipment. -Deletion of the' individual l

1eakage rate forsthese valves'does not affect the. severity

of- l any. accident previously evaluated. :The consequences of:a- l valve failure or malfunction ~are not' increased by removal;of  :

- the. acceptance criteria, leakage raterwill'still-be measured; .j on a quarterly' basis-as is currently done tofdetermine"if the a seals are. degrading.  !

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. c) . Reduce,the' margin of safety as defined in the basis for.any_  !

' technical specification. The proposed revision to the T/S j does not reduce the margin of safety assumed in any accident i analysis. The valves will still be surveilled on a quarterly- 1 basis to verify leakage and seal degradation to assure gross j

, . failure will not occur and that containment integrity is  !

maintained.  !

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' Conclusion  !

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Given the aboveIdiscussions as well as those presented in the l

-Significant Hazards Consideration, the proposed change does not  !

adversely' affect or endanger the health or safety.of the general  !

public or involve a significant safety hazard.-  ;

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Att0chment 2 Pago 1 of 2 ULNRC-03151

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SIGNIFICANT HAZARDS CONSIDERATION )

ProDosed Change .

This amendment request revises Technical Specification (T/S) ,

Surveillance Request 4.6.1.7.4 and its associated Bases to delete  :

the requirement to verify quarterly that the measured leakage rate is less than 0.05 times the maximum allowable leakage rate (L,)

for each 18-inch containment mini-purge supply and exhaust isolation valve. This requirement would be replaced with a quarterly requirement to demonstrate operability by verifying that when the measured leakage rate for these valves is added to the leakage rates determined pursuant to Specification 4.6.1.2d for all other Type B and C penetrations, the combined leakage rate is less than 0.60 L, . The valves will still be inspected during this quarterly surveillance to assure the resilient seal material has not degraded.

The proposed revision to T/S Surveillance Requirement 4.6.1.7.4 l and its associated Bases to delete the requirement to verify quarterly that the individual measured leakage rate for each 18-inch containment mini-purge supply and exhaust isolation valve is less than 0.05 times the maximum allowable leakage rate is consistent with the guidance provided in NUREG-1431. The proposed revision does not involve a significant hazards consideration because operation of Callaway Plant with this change would not:

a) Involve a significant increase in the probability or consequences of an accident previously evaluated. The proposed revision to the T/S will not adversely impact plant safety since the requirement to perform the quarterly surveillance will still be implemented to verify valve leakage and seal degradation. The mini-purge valves will still perform their intended safety function to close within .

5 seconds after receipt of an isolation signal.

b) Create the possibility of a new or different kind of accident from any previously evaluated. There are no design changes being made that would create a new type of accident or malfunction and the method and manner of plant operation remain unchanged. Deletion of the individual leakage rate for these valves does not affect tre severity of any accident previously evaluated. The consequences of a valve failure or malfunction are not increased by the removal of the acceptance criteria, leakage rate will still be measured on a ,

quarterly basis as is currently done to determine if the seals are degrading.

c) Involve a significant reduction in a margin of safety. There are no changes being made to the safety limits or safety system settings that would adversely impact plant safety.  ;

The valves will still be surveilled on a quarterly basis to verify leakage and seal degradation to assure gross failure will not occur and that containment integrity is maintained.

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-Attachment 2 l N

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Paga 2 of-2 d '

ULNRC-03151 Based on.the~above' discussions, it has-been determined that-the. >

requested Technical Specification change does not involve a significant increase in the probability or consequences of an

_ accident.or create the possibility of a new or different kind of  ;

accident or condition over previous evaluations; or involve a-

-significant reduction in a margin of safety. Therefore, the requested license amendment does not involve a significant hazards consideration.

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. Attachm:nt 3 Paga 1 of 1 ULNRC-03151 ENVIRONMENTAL CONSIDEkATION This amendment application revises the surveillance requirements of Technical Specification 4.6.1.7.4 and its associated Bases to delete the requirement to verify quarterly that the measured leakage' rate is less than 0.05 times the maximum allowable leakage rate for each 18-inch containment mini-purge supply and exhaust valve. This requirement would be replaced with a quarterly requirement to demonstrate operability by verifying that when the measured leakage rate for these valves is added to the leakage rates determined pursuant to Specification 4.6.1.2d for all other Type B and C penetrations, the combined leakage rate is less than 0.60 times the maximum allowable leakage rate.

The proposed amendment involves changes with respect to the use of facility components located within the restricted area, as defined in 10 CFR 20 and revises surveillance requirements. Union Electric has determined that the proposed amendment does not involve:

(1) A significant hazards consideration, as discussed in Attachment 2 of this amendment application; (2) A significant change in the types or significant increase in the amounts of any effluents that may be released offsite; (3) A significant increase in individual or cumulative occupational radiation exposure.

Accordingly, the proposed 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 this amendment.