RBG-26408, Application for Amend to License NPF-47,revising Tech Specs Requirements to Perform Addl Operability Testing of Diesel Generator Only When Conditions Warrant.Fee Paid

Application for Amend to License NPF-47,revising Tech Specs Requirements to Perform Addl Operability Testing of Diesel Generator Only When Conditions Warrant.Fee Paid

ML20237F918
Person / Time
Site:	River Bend
Issue date:	08/07/1987
From:	Deddens J GULF STATES UTILITIES CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20237F921	List: ML20237F938 RBG-26408, Application for Amend to License NPF-47,revising Tech Specs Requirements to Perform Addl Operability Testing of Diesel Generator Only When Conditions Warrant.Fee Paid
References
RBG-26408, NUDOCS 8708130228
Download: ML20237F918 (11)

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,.s GUEF STATES UTELITIES COMPANY RIVER BEND ST ATION POST OFFICE BOX 220 ' 57. FRANCISVILLE. LOUIStANA 70775 AREA CODE $04 836 60945 346 8651 3 August 7, 1987 ,

RBG- 26408 )

File Nos. G9.5, G9.25.1.4 U.S. Nuclear Regulatory Commission Document Control Desk Washington, D.C. 20555  !

Gentlemen:

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I River Bend Station - Unit 1 Docket No. 50-458 Gulf . States Utilities (GSU) hereby files an amendment ~to the River Bend Station Unit 1 Technical Specifications, Appendix A to Facility Operating License NPF-47, pursuant to 10CFR50.90. This application is filed to revise Technical Specification 3.8.1.1, ?.C Sources-Operating.

Actions relating to demonstrating the diesel generators operability with I offsite circuits inoperable or onsite diesel. generators . inoperable.

Attachments- 1 and 2- address the offsite and onsite AC sources, respectively. The Enclosure contains the proposed revisions to the River Bend Station Technica1' Specifications.

River Bend Station Technical Specification 3.8.1.1, AC Sources-Operating currently requires that diesel generator operability be demonstrated as a result of conditions which may not have, and in most cases do not have, an impact on the reliability of the diesel generators. This requested change will revise these requirements to perform additional operability testing only when conditions warrant. This change would j therefore result in further reducing excessive test starts. River Bend' l Station has previously incorporated the recommendations of Generic Letter 85-16.

Pt osuant to 10CFR170.12, GSU has enclosed a check in the amount of one-hundred and fifty dollars ($150.00) for the- license amendment application fee. Your prompt attention to this application is apprecia'ed.

Sincerely, v 1 J. C. Deddens '

b Senior Vice President D ,

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.tAl River Bend Nuclear Group

/ ERG DAS/ch el 4040 Attachments 8708130228 870007 PDR ADOCK 05000458 p PDR w

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UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION l 1

l STATE OF LOUISIANA )

PARISH OF WEST FELICIANA )

In the Matter of ) Docket No. 50-458 50-459 .I GULF STATES UTILITIES COMPANY )

(River Bend St'ation, Unit 1)

AFFIDAVIT J. C. Deddens, being duly sworn, states that he is a Senior Vice President of Gulf States Utilities Company; that he. is authorized on the part of said company to sign and file with the Nuclear Regulatory Commission the documents attached hereto; and that all such documents are true and correct to the best of his knowledge, information and belief.

, / ' W J.'b.Deddens Subscribed and sworn to before me, a Notary Public in and for the State and Parish above named, this 7h1 day of k110)LAbf , 19 b.

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[Joan W. Middlebrooks Notary Public in and for West Feliciana Parish, Louisiana My Commission is for Life.

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cc: ' Mr. Robert D. Martin, Regional Administrator U.S. Nuclear Regulatory Commission I Region IV 611 Ryan Plaza Drive, Suite 1000

~11ngton, TX 76011 ARC Senior Resident Inspector P.O. Box 1051 St. Francisv111e, LA 70775 Mr. William H. Spell, Administrator Nuclear Energy Division Louisiana Department of Environmental Quality P.O. Box 14690 Baton Rouge, LA 70898

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ATTACHMENT 1 j GULF STATES UTILITIES COMPANY RIVER BEND STATION l DOCKET 50-458/ LICENSE NO. NPF-47 l

AC SOURCES - 0FFSITE LICENSING DOCUMENT INVOLVED: TECHNICAL SPECIFICATIONS ITEMS: 3.8.1.1 Action a ~

PAGE: 3/4 8-1 3.8.1.1 Action f 3/4 8-2 and 8-3 I

REASON FOR REQUEST A change is being requested in accordance with 10CFRf0.90 to remove the j requirements to start the diesel generators (DG) under degraded offsite l power conditions. River Bend Station Technical Specification 3.8.1.1, l

AC Sources-Operating, Actions a and f currently require that the diesel '

generators be demonstrated operable by performing surveillance requirements 4.8.1.1.2.a.4 and 4.8.1.1.2.a.5 with offsite circuits inoperable. This proposed change would therefore result in further r'ducing the number of excessive test starts and reduce unnecessary hardship on the equipment. River Bend Station has previously incorporated the recommendations of Generic Letter 85-16.

DESCRIPTION As addressed in IE Information Notice 84-69, and Supplement 1 " Operation of Emergency Diesel Generators," when a DG is operated connected to offsite sources and nonvital loads, disturbances in thes-e areas can adversely affect DC reliability. Further, this reliability is significantly reduced when the offsite circuits are degraded or not available. Additionally, a demand for emergency DG start is more probable while connected to the grid and nonvital loads for the required ,

surveillance. These surveillance require the diesel generatora be started and reach rated speed, voltage and frequency within 10 seconds, be synchronized to the grid, and be fully loaded in less than 60 seconds for at least one hour.

This proposed change would delete the requirements to start the diesel generators, synchronize and load them to the safety buses in Actions a and f during periods when offsite power is in a degraded condition. The required " demonstration" of DG operability was intended to add assurance l of availability of onsite AC sources in the event of degraded offsite sources. It is contended that adequate assurance of DG operability is maintained by the frequencies specified in the normal Technical Specification surveillance requirements. Additionally, as stated above, l assurance of DG availability is lessened by a demonstration requiring  !

connecting the DGs to offsite sources when the offsite sources are  !

abnormally degraded.  !

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SIGNIFICANT HAZARDS CONSIDERATIONS As required by 10CFR50.92, the following is provided to the NRC Staff in support of'"no significant hazards considerations."

1. No significant increase in the probability or the consequences of an accident previously evaluated results from this change because:

The required " demonstration" of DG operability was intended to add assurance of availability of onsite AC sources in the event of l degraded offsite sources. It is contended that adequate assurance of DG operability is maintained by the testing frequencies specified

=in the normal Technical Specification surveillance requirements. j Assurance' of DG availability is lessened by a demonstration j requiring connecting the DGs to offsite sources when the offsite '

sources are abnormally degraded.

Additionally , as outlined in IE Information Notice 84-69 and Supplement 1, " Operation of Emergency Diesel Generators,"

potentially significant safety problems can arise when one or more DGs are operated in modes other-than the prescribed standby service mode (such as in parallel with offsite power sources as required by the subject Actions). Testing of DGs when offsite circuits are in jeopardy can lead to a complete loss of-AC power to safety buses.

Therefore, not testing DGs as currently required by Technical Specification 3.8.1.1 regarding inoperable offsite circuits will tend to decrease the probability or the consequences of an accident previously. evaluated.

2. This change would not create the possibility of a new or different kind of accident from any accident previously evaluated because:

By not testing DGs as currently required by Technical Specification l' Section 3.8.1.1, no possibility of a new or different accident than previously evaluated is created because no new modes of operation are introduced. 'All equipment functions remain as previously evaluated in the River Bend Station FSAR and SER. Conformance with applicable Regulatory Guides is maintained as indicated in FSAR Section 1.8.

3. This change would not involve a significant reduction in the margin of safety because:

The DCs are less vulnerable when in their normal standby alignment i and not parallel to the grid. As outlined in IE Information Notice I 84-69 and Supplement 1, " Operation of Emergency Diesel Generators,"

potentially significant safety problems can arice when one or more DGs are operated in modes other than the prescribed standb. service mode (such as in parallel with offsite power sources as requ; red by the subject actions). Testing of DGs when offsite circuits are in jeopardy can lead to a complete loss of AC power to safety buses. I Therefore, not testing DGs as currently outlined in Technical Specification 3.8.1.1 will tend to increase the margin of safety by

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not exposing DGs to the offsite transmission network when it is in a ,

degraded condition. Additionally, the Technical Specification bases {

do not define any margin or safety for this surveillance j requirement. j The proposed amendment as discussed above, has not changed the system i design, function or operation as discussed in the FSAR and therefore, will not increase the probability or the consequences- of a previously evaluated accident and will not create a new or different accident.

Adequate assurance of DG availability is maintained by the testing frequencies specified in the normal Technical Specification surveillance requirements. Also, the results of the change are clearly within acceptable criteria with respect to system components' and design requirements. As a result, the ability to perform as described in the FSAR is maintained and therefore, the proposed change does not result in a significant reduction in the margin of safety. Therefore, GSU proposes that no significant hazards are involved.

REVISED TECHNICAL SPECIFICATION The requested revisfon is provided in the Enclosure.

SCHEDULE FOR ATTAINING COMPLIANCE As indicated above, River Bend Station is currently in compliance with the applicable Technical Specification.

NOTIFICATION OF STATE PERSONNEL A copy of this amendment application has been provided to the State of Louisiana, Department of Environmental Quality - Nuclear Energy Division.

ENVIRONMENTAL IMPACT APPRAISAL Revision of this Technical Specification does not result in an environmental impact beyond that previously analyzed. Therefore, approval of this amendment does not result in a significant environmental impact nor does it change any previous environmental impact statements for River Bend Station.

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f ATTACHMENT 2 GULF STATES UTILITIES COMPANY RIVER BEND STATION DOCKET 50-458/ LICENSE NO. NPF-47 AC SOURCES - ONSITE LICENSING DOCUMENT INVOLVED: TEC3NICAL SPECIFICATIONS ITEMS: 3.8.1.1 Action b PAGE: 3/4 8-1 3.8.1.1 Action c 3/4 8-2 3.8.1.1 Action d 3/4 8-2 3.8.1.1 Action g 3/4 8-3 3/4.8.1 Bases B 3/4 8-1 i REASON FOR REQUEST i River Bend Station Technical Specification 3.8.1.1, AC Sources-Operating, Actions b, c, d, and g currently require that with a diesel i generator (DG) inoperable due to any cause other than preplanned preventive maintenance or testing, the remaining DGs be demonstrated operable by performing surveillance requirements 4.8.1.1.2.a.4 and 4.8.1.1.2.a.5. This proposed change would therefore result in further reducing the number of excessive test starts and reduce unnecessary hardship on the equipment. River Bend Station has previously incorporated the recommendations of Generic Letter 85-16.

DISCUSSION These Technical Specification surveillance require the DGs be started and reach rated speed, voltage and frequency within 10 seconds, be synchronized to the grid, and be fully loaded in 60 seconds for at least one hour. This proposed change would revise these Actions to require the operability of the remaining DGs be demonstrated only if the other DG became inoperable as a result of a " valid failure" as defined in US NRC Regulatory Guide 1.108, " Periodic Testing of Diesel Generator Units Used as Onsite Electric Power Systems at Nuclear Power Plants", Revision  !

1, August 1977.

The requirements to demonstrate the operability of the remaining operable DGs during these events are, in part, to verify that no common mode / generic failures exist on the redundant DGs. There are countless circumstances which could render a DG inoperable and not bring into question the possibility of a similar " generic" problem with other onsite DGs (e.g., any number of auxiliary support system Iailures which are easily detected and are functional on redundant DGs). If the inoperability was a readily identified failure under non-operating circumstances and can be assured not to exist on the remainine operable i DGs, there should be no requirement to operate any o aer DG to i

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demonstrate its operability. If the inoperable DG was a result of a

. failure during operation and is related to its ability to perform its safety related function, it would then seem appropriate to subject the remaining operable DGs to an additional demonstration to show no common mode / generic problem exists. As outlined in Regulatory Guide 1.108 and the Technical Specifications, it is " valid failures" which should require increased scrutiny and increased testing to. assure DG availability. If a DG were discovered inoperable while in the standby service mode (i.e., no failure during a valid test) then the potential j common mode / generic failure can be investigated and operability of the remaining DGs verified without increased testing.

I There have been numerous instances where River Bend Station has l performed the required surveillance on redundant DGs when the type of event which initially rendered the DG inoperable did not require i performance of the DG's surveillance test to restore it to operable status. This appears to be an obvious case of excessive testing of redundant DGs. Specific instances of inoperable DGs which were not the result of a " valid failure" include:

- Blown fuse to lube oil pump with DG in standby.

- Breaker trip on DG room exhaust fan with DG in standby.

- Invalid " Loss of Generator Field" alarm during surveillance testing resulting in manual DG shutdown. l

- Service water valve to DG failed ISI surveillance.

- Division III battery declared' inoperable.

- Seiemic restraint found non-functional with DG in standby.

There art additional instances - some repetitious.

Other circumstances have the potential for generating unnecessary DG starts per their associated Action statements. Specifically, the River Bend Station Technical Specifications have a few Action statements which ,

require the administrative inoperability of a DG (i.e., Specifications:

3.3.3-1 Action 36 and 37, 3.5.1 Action c.1, 3.7.1.1 Action a, 3.8.2.1 Action b, and 3.8.3.1 Action a.2).

In conclusion, the required demonstration may be perceived to provide added assurance of the availability of onsite AC sources. However, as addressed in IE Information Notice 84-69 and Supplement 1, " Operation of Emergency Diesel Generators," when a DG is operated connected to offsite sources and nonvital loads, disturbances can adversely affect DG reliability. Assurance of availability is therefore lessened by a demonstration of operability requiring connection of the DGs to offsite and nonvital loads at a time when one other DG is already inoperable.

It is contended that adequate assurance of operability is maintained by the testing frequencies specified in the normal Technical Specification surveillance requirements.

SIGNIFICANT HAZARDS CONSIDERATIONS As required by 10CFR50.92, the following is provided to the NRC Staff in support of "no significant hazards considerations."

1. No significant increase in the probability or the consequences of an accident previously evaluated results from this change because:

This change does not affect the availability or function of equipment and/or systems. The reduction in DG testing would not subject the remaining redundant operable DGs to periods of inoperability and reduced reliability while connected to offsite and nonvital loads which occur during the required testing when one other DG is already inoperable. This would tend to decrease the probability or consequences of an accident previously evaluated.

2. This change would not create the possibility of a new or different kind of accident from any accident previously evaluated because: l By not testing the remaining operable DGs as currently required by Technical Specification 3.8.1.1, no possibility of a new or different accident previously evaluated is created because no new medes of operation are introduced. All equipment functions remain as previously evaluated in the River Bend Station FSAR and SER.

Conformance with applicable Regulatory Guides is maintained as indicated in FSAR Section 1.8.

3. This change would not involve a ciF nificant reduction in the margin of safety because:

The perceived gain in safety from demonstrating the operability of the remaining redundant DGs upon the loss of one DG is, in part, to identify potential common mode / generic failures. If a DG were discovered inoperable while in the standby service mode (i.e., no failure during a " valid test") then the potential common mode / generic failure can be investigated and operability of the remaining DGs verified without increased testing. Furthermore, the increased testing represents a reduction of the margin safety due to the vulnerability of the DG when connected to offsite and nonvital loads. Additionally, the Technical Specification bases do not define any margin of safety for this surveillance requirement.

The proposed amendment, as discussed above, has not changed the system design, function or operation as discussed in the FSAR and therefore, will not increase the probability or the consequences of a previously evaluated accident and will not create a new or different accident.

c.dequate assurance of DG availability is maintained by the testing frequencies specified in the normal Technical Specification surveillance l requirements. Also, the results of the change are clearly within acceptable criteria with respect to system components, design requirements and applicable Regulatory Guides. As a result, the ability )

to perform as described in the FSAR is maintained and therefore, the proposed change does not result in a significant reduction in the margin

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of safety. Therefore, GSU proposes that no significant hazards i considerations are involved.

. REVISED TECHNICAL SPECIFICATION The requested revision is provided in the Enclosure.

1 SCHEDULE FOR ATTAINING COMPLIANCE As indicated above, River Bend Station is currently in compliance with the applicable Technical Specification.

NOTIFICATION OF STATE PERSONNEL A copy of this amendn:ent application has been provided to the state of Louisiana, Department of Environmental Quality - Nuclear Energy Division.

ENVIRONMENTAL IMPACT APPRAISAL i

Revision of this Technical Specification does not result in an environmental impact beyond that previously analyzed. Therefore, approval of this amendn;ent does not result in a- significant environmental impact nor does it change any previous- environmental impact statements for River Bend Station.

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D ENCLOSURE

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