ST-HL-AE-5076, Application for Amends to Licenses NPF-76 & NPF-80.Amends Would Incorporate Proposed Addition of TS 3.10.8 (Special Test Exception)

Application for Amends to Licenses NPF-76 & NPF-80.Amends Would Incorporate Proposed Addition of TS 3.10.8 (Special Test Exception)

ML20087H851
Person / Time
Site:	South Texas
Issue date:	05/01/1995
From:	Cloninger T HOUSTON LIGHTING & POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20083J995	List: ML20083J994 ML20087H856 ST-HL-AE-5076, Application for Amends to Licenses NPF-76 & NPF-80.Amends Would Incorporate Proposed Addition of TS 3.10.8 (Special Test Exception)
References
ST-HL-AE-5076, NUDOCS 9505050071
Download: ML20087H851 (10)

Text

The Light c o m p a n y Seth Texas Project acctric &nerating Station M Box m Wadsworth,Tesas m83 Houston Lighting & Power May 1, 1995 ST-HL-AE-5076 File No.: G20.02.01 10CFR50.90, 10CFR50.92, 10CFR51 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 South Texas Project Units 1 & 2 Docket No. STN 50-498 and STN 50-499 Unit I and Unit 2 Technical Specification 3.10.8 Houston Lighting & Power Company proposes to amend its Operating License NPF-76 and NPF-80 for the South Texas Project Electric Generating Station, Units 1 and 2, by incorporating the attached proposed addition of Technical Specification 3.10.8. This proposed Special Test Exception would allow extension of the Standby Diesel Generator Allowed Outage Time for a cumulative 21 days on each Standby Diesel Generator once per fuel cycle. In addition, it would also extend the Allowed Outage Time on each Essential Cooling Water loop for a cumulative 7 days once per fuel cycle. These extended Allowed Outage Times will be used to perform required inspections and maintenance on the Standby Diesel Generators and Essential Cooling -

Water system during power operation.

Houston Lighting & Power has reviewed the attached proposed amendment pursuant to 10CFR50.92 and determined that it does not involve a significant hazards consideration. In addition, Houston Lighting & Power has determined that the proposed amendment satisfies the criteria of 10CFR51.22(c)(9) for categorical exclusion from the requirement of an environmental assessment. The South Texas Project Electric Generating Station Nuclear Safety Review Board has reviewed and approved the proposed changes.

The required affidavit, along with a Safety Evaluation and No Significant Hazards Consideration Determination associated with the proposed changes, and the marked up affected pages of the Technical Specifications are included as attachments to this letter.

Houston Lighting & Power requests this amendment be approved and issued by August 1,1995 to support the upcoming outage on Unit 2.

,.ce -

2V P ject Manager on Behalf of the Participants in the South Texas Project ,

9505050071 950501 ~

PDR ADDCK 05000498 l P PDR l

l i

Houston Lighting & Power Company l South Texas Project Electric Generating Station ST-HL-AE-5076  !

File No.: G20.02.01 i Page 2 l If you should have any questions concerning this matter, please call Mr. M. A. McBurnett at .

(512) 972-7206 or myself at (512) 972-8664.

I a

c H. Clon' ger i Vice Pre dent l Nucle En ' eering l TCK/lf  !

~!

Attachment:

1. Affidavit

2. Safety Evaluation and No Significant Hazards Consideration Determination l

3. Mark-ups of Proposed Changes to Technical Specification 3.7.4,3.8.1.1, 4.8.1.1.2 and 3.10.8.

4. Evaluation of the Proposed Special Test Exception for Diesel Generator -

and Essential Cooling bater Maintenance. l I

1 l

l i

i

)

750 95',95-116 002

p-le s

' Houston Lighting & Power Company ST-HL-AE~5076 South Texas Project Electric Generating Station p;; g , G20.02 01 i Page 3  :

c:

~

Leonard J. Callan 'Rufus S. Scott

< Regional Administrator, Region IV Associate General Counsel  ;

U. S. Nuclear Regulatory Commission - Houston Lighting & Power Company 611 Ryan Plaza Drive, Suite 400 P. O. Box 61067  ;

Arlington,' TX - 76011-8064 Houston, TX 77208 Thomas W. Alexion Institute of Nuclear Power Project Manager Operations - Records Center U. S. Nuclear Regulatory. Commission 700 Galleria Parkway -

Washington, DC 20555-0001 13H15 Atlanta, GA 30339-5957 David P. Loveless Dr. Joseph M. Hendrie Sr. Resident Inspector 50 Bellport Lane e/o U. S. Nuclear Regulatory Comm. Bellport, NY l1713 P. O. Box 910 Bay City, TX 77404-0910 Richard A. Ratliff -i Bureau of Radiation Control J. R. Newman, Esquire Texas Department of Health Morgan, Lewis & Bockius 1100 West 49th Street ,

1800 M Street, N.W. Austin, TX 78756-3189 Washington, DC 20036-5869 U. S. Nuclear Regulatory Comm.

K. J. Fiedler/M. T. Hardt Attn: Document Control Desk City Public Service Washington, D. C. 20555-0001 P. O. Box 1771 San Antonio, TX 78296 J. C. Lanier/M. B. Lee J. R. Egan, Esquire City of Austin Egan & Associates, P.C. .

Electric Utility Department 2300 N Street, N.W. ,

721 Barton Springs Road Washington, D.C. 20037 Austin, TX 78704 C. A. Johnson i Central Power and Light Company  !

P. O. Box 289 Mail Code: N5012 Wadsworth, TX 77483 3 l

t t

5 i

I

'l l

)

i i

I i

l l

l l

l l

l l

i l

l ATTACHMENT 1 I 1

1 AFFIDAVIT TSC 95ies ll6 002

y UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION p In the Matter of )

)

liouston Lighting & Power ) Docket Nos. 50-498 & 50-499 Company, et al., )-

)

South Texas Project )

Units 1 and 2 )

AFFIDAVIT I, T. H. Cloninger, being duly sworn, hereby depose and say that I am Vice President, Nuclear Engineering, of Housten Lighting & Power Company; that I am duly authorized to sign and file with the Nuclear Regulatory Commission the attached revision to proposed changes to Technical Specification 3.10.8; that I am familiar with the content thereof; and e matters set forth therein are true and correct to the best of my knowledge and beli f . D I

/% J /

. I.'Cloninger ice Presiden uclear En ' .e ng STATE OF TEXAS )

)

)

Subscribed and sworn to before me, a Notary Public in and for the State of Texas, this

/ , day of A a( ,1995.

Y&

Notary Public in and for the V A

State of Texas l UN RITTENBERRY l* Netary PuMr. State Of Teses her Commenen Expires 10/9/97

( '~

lL ___-_- -

75C.95\95-134 002

l e

ATTACHMENT 2 SAFETY EVALU.ATION ,

AND NO SIG-NIFICANT HAZARDS CONSIDERATION DETERMINATION l

l 1

i l

l a

i ST-HL-AE-5076 I Attachment 2 Page 1 of 4 Hackground: l l

Ilouston Lighting & Power company (IIL&P) requests the addition of Technical Specification (TS) 3.10.8. The purpose of this amendment is to provide a Special Test Exception that j would extend the allowed outage times once per fuel cycle for the Standby Diesel Generator and the Essential Cooling Water systems at the South Texas Project Electric Generating Station.

Description of the Proposed C.%nge:

The proposed Special Test Exception would allow a Standby Diesel Generator Allowed l

Outage Time for a cumulative 21 days on each Standby Diesel Generator once per fuel cycle.  !

A footnote is added to Surveillance Requirement 4.8.1.1.2 to allow credit for events that  !

satisfy these requirement, in addition, it would also allow an Allowed Outage Time on each Essential Cooling Water loop for a cumulative 7 days once per fuel cycle.  :

i Safety Analysis:  !

The requested Technical Specification special test exception addition does not modify any i plant hardware or operational procedures, it simply changes the time frame in which existing l authorized activities can be performed. Consequently, the design basis of the plant is  !

unaffected and therefore, risk-based analysis can be an appropriate decision basis.  !

i The risk basis is anchored to the results ofIlouston Lighting and Power Company's (IIL&P) j state-of-the-art and plant-specific Probabilistic Safety Assessment (PSA) model, which has been reviewed by the Nuclear Regulatory Commission. This model was updated and extended to Level 2 standards to meet the Individual Plant Evaluation (IPE) requirements contained in Generic Letter 88-20. It was further refined and updated to provide the assessment of the risk impacts of test and maintenance activities at the South Texas Project Electric Generating Station and to provide the information requested by the Nuclear  ;

I Regulatory Commission for reviewing the risk-based evaluation of Technical Specifications submitted in 1993.

The South Texas Project Electric Generating Station and the Nuclear Regulatory Commission {

staff mutually agreed to use South Texas Project Level 2 PSA/IPE as the baseline for the risk- i based evaluation of Technical Specifications. It is now further updated and enhanced in this

[

submittal to incorporate revision to Technical Specifications granted by the Nuclear  ;

Regulatory Commission and to incorporate plant specific failure data, and other plant features j not previously included (e.g., emergency transformer). The previously reported Level 2 PSA/IPE mean core damage frequency (CDF) was found to be about 4.4E-5 per reactor year and the mean large early release frequency (LERF) was found to be about lE-6 per reactor l year. }

l l

l I

f

ST-HL-AE-5076  ;

Attachment 2 l Page 2 of 4 This submittal is an extension of that baseline to reflect the current licensing basis at South [

Texas Project Electric Generating Station. The requantification of the risk-based evaluation of  :

the Technical Specification's Special Test Exception section using the updated Level 2 l PSA/IPE models has now been completed and is included in this submittal as Attachment 4.

The decision criteria used in this evaluation is to accept only those changes that do not result !

in a significant increase in CDF or in LERF. In addition to the proposed Special Test Exception, the planned maintenance program is being procedurally modified and is explicitly accounted for in this submittal with the intention of reducing risk levels and achieving i equipment performance impmvements that are cost effective. This has been demonstrated by the combined effects of maintaining at-power risk levels below that which was reported for Generic Letter 88-20 and implementing improvements in outage schedulmg which will  ;

increase the overall availability of on-site power sources during sht.tdown conditions. The results in Section 3 of Attachment 4 show that through the combination of the proposed technical specification change, the incorporation of quantified compensatory measures, the {

incorporation of plant features not previously credited in the PSA, and the incorporation of plant specific data (which more closely reflects the current plant experience), there are no  !

significant increases in CDF or LERF over those reported in the South Texas Project Level 2 PSA/IPE submission or the previous risk based evaluation of Technical Specifications. The l effect of the changes would actually result in a small net decrease in CDF. The very small l net increase in LERF due to the combination of these changes is ins;gnificant in relation to i the underlying uncertainties. The current mean point estimates of CDF and LERF for the new base case plus the proposed Special Test Exception are 2.30E-5 and 5.07E-7 per year, respectively. Ilence, the proposed technical specification changes meet the decision criteria selected for this evaluation. Moreover, considering the unquantified reduction in risk due to the increased onsite power sources available during shutdown conditions, a larger decrease in {

CDF is conceivable as a result of these Technical Specification changes.

l The requested change provides plant operations and maintenance personnel additional 1 flexibility to plan Standby Diesel Generator and Essential Cooling Water System train maintenance, testing, troubleshooting activities, and optimize overall plant conditions, from a risk perspective, while avoiding administrative requirements for power reduction transients that could increase the potential for plant trips which challenge safety systems. It is anticipated that unquantified benefits to the plant's operations and maintenance activities relative to the Standby Diesel Generator and Essential Cooling Water System will also be realized by the proposed Special Test Exception. These benefits which will be the result of improved maintenance effectiveness due to the removal of competing plant maintenance and refueling tasks, improved human performance due to a more balanced workload on the  ;

maintenance personnel, better root cause analysis and enhanced corrective actions t implementation due to a ibcused workforce, and improved equipment performance due to  ;

better maintenance effectiveness. The impact of all the above effects is expected to contribute to long term reductions in risk to the public, which can be confirmed as future performance data is collected and trended.

1 i

l I

l 1

ST-HL-AE-5076 Attachment 2 Page 3 of 4 NO SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION l Pursuant to 10CFR50.91, this analysis provides a determination that the proposed change to  :

the Technical Specifications described previously, does not involve any significant hazards consideration as defined in 10CFR50.92, as described below

1. The proposed change does not involve a significant increase in the probability or  !

consequences of an accident previously evaluated. i The Standby Diesel Generators are not accident initiators, therefore the increase in Allowed l Outage Times for this system does not increase the probability of an accident previously (

evaluated. The three train desigr. of the South Texas Project ensures that even during the seven days the Essential Cooling Water loop is inoperable there are still two complete trains j available to mitigate the consequences of any accident. If the Essential Cooling Water loop is  !

not inoperable during the 21 days the Standby Diesel Generator is inoperable, the Standby Diesel Generator's Engineered Safety Features bus and equipment in the train will be i operable. This ensures that all three redundant safety trains of the South Texas Project design are operable. In addition the Emergency Transformer will be available to supply the Engineered Safety Features bus normally supplied by the inoperable Standby Diesel Generator. These actions will ensure that the changes do not involve a significant increase in i the consequences of previously evaluated accidents.

2. The proposed change does not create the possibility of a new or different kind of  ;

accident from any accident previously evaluated. i The proposed changes affect only the magnitude of the Standby Diesel Generator and i Essential Cooling Water Allowed Outage Times once per fuel cycle as identified by the marked-up Technical Specification. As indicated above, the proposed change does not i involve the alteration of any equipment nor does it allow modes of operation beyond those currently allowed. Therefore. implementation of these proposed changes does not create the  !

possibility of a new or different kind of accident from any accident previously evaluated.  !

3. The proposed change does not involve a significant reduction in a margin of safety.

The proposed changes result in no significant increase in core damage or large early release ,

frequencies. ,

l Three sets of PSA results have been presented to the NRC for the South Texas Project. One l submitted in 1989 from the initial Level 1 PSA of internal and external events with a mean annual average CDF estimate of 1.7 x 10", a second one submitted in 1992 to meet the IPE i requirements from the Level 2 PSA/IPE with a CDF estimate of 4.4 x 104, and an update of l the PSA that was reported in the August 1993 Technical Specifications submittal with a ,

variety of CDF estimates for different assumptions regarding the rolling maintenance profile and different combinations of modified Technical Specifications. The South Texas Project PSA was updated in March of 1995 to include the NRC approved Risk-Based Technical l

1 ST-ilL-AE-5076 Attachment 2 Page 4 of 4 Specifications, Plant Specific Data and incorporate the Emergency Transformer into the ,

model. This update resulted in a CDF estimate of 2.07 x 104 When the requested changes are modeled along with the compensatory actions, the resulting CDF estimate is 2.30 x 104 While this is siightly higher (approx.11%) than the updated results, it is still significantly lower (approx. 46%) than the previous Risk-Based Evaluation of Technical Specification submitted in 1993. Therefore, it is concluded that there is no significant reduction in the margin of safety.

Based on the above evaluation, Houston Lighting & Power has concluded that these changes do not involve any significant hazards considerations.

Implementation Schedule:

llouston Lighting & Power requests an implementation time of 30 days from the effective date of the approved license amendment to facilitate distribution and to make appropriate changes to plant documents.

I l

i