ML20217J415

Forwards Request for Addl Info Re Util 990624 Application for Amend of TSs That Would Revise TS for Weighing of Ice Condenser Ice Baskets

ML20217J415
Person / Time
Site:	Sequoyah
Issue date:	10/15/1999
From:	Hernan R NRC (Affiliation Not Assigned)
To:	Scalice J TENNESSEE VALLEY AUTHORITY
References
TAC-MA6065, TAC-MA6066, NUDOCS 9910250080
Download: ML20217J415 (6)

Text

,

October 15, 1999 l

Mr. J. A. Scalice

, President, TVA Nuclear and 1

Chief Nuclear Officer Tennessee Valley Authority ,

6A Lookout Place 1101 Market Street Chattanooga, Tennessee 37402-2801

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION ON CLARIFICATION OF ICE i CONDF.NSER ICE WEIGHING REQUIREMENTS FOR THE SEQUOYAH I NUCLEAR PLANT, UNIT 1 AND 2 (TAC NO. MA6065 AND MA6066) ,

Dear Mr. Scalice:

s  !

On June 24,1999, Tennessee Valley Authority (licensee of Sequoyah Nuc!aar Plant (SON),

Units _1 and 2) submitted an application for amendment of the Technical Specifications (TS) that would revise the TS for the weighing of ice condenser ice baskets. The changes were identified as being consistent with a companion r'evision to the Improved Standard TS (ISTS), as submitted by the Nuclear Energy institute (NEI) Technical Specification Task Force to the U.S.

Nuclear Regulatory Commission staff on June 23,1999. The staff's review of the application has resulted in the enclosed request for additional information (RAl), as provided in the enclosure. Due to the simultaneous nature of the review of the SON and NEl submittals, the attached RAI also include requests related to the proposed changes to the ISTS.

As discussed with your staff on October 14,1999 we understand that you plan to respond to the enclosed RAI on or about December 17,1999.

Sincerely, Original signed by:

Ronald Hernan, Senior Project Manager Project Directorate 11-3 Division of Reactor Projects -l/II Office of Nuclear Reactor Regulation Docket Nos. 50-327 and 50-328

Enclosure:

Request for AdditionalInformation I cc w/ enclosure: See next page 'i DISTRIBUTION:

" Docket File OGC ACRS SQN Rdg. C.Li PUBLIC S. Black R.' Hernan B. Clayton s i) k P. Fredrickson, Rll J.Hannon DOCUMENT NAME: G:\PDll-2\SQN\RAIA6065.wpd R. Mart;n W. Beckner See previous concurrence g

d To receive a copy of thle document. Indicate in the box: "C" = Copy without attachment /endosure 'E" - Copy wi9 attachment / enclosure

• N* = No copy OFFICE PDll-2\PM PDil-2\PM ,

PDll-2\LA TSB\BC DSSA PDil-2\SC_M NAME RMartin' RHemanM'BClayton* WBeckner* JHannon* SPetersodO DATE 9/30/99 10/14/99 ' 9/30/99 10/1 /99 9/30/99 10/ / f/99 OFFICIAL RECORD COPY

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UNITED STATES s* j- NUCLEAR REGULATORY COMMISSION o e WASHINGTON, D.C. 20$5&0001

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October 15,1999 Mr. J. A. Scalice President, WA Nuclear and Chief Nuclear Officer Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, Tennessee 37402-2801

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION ON CLARIFICATION OF ICE

. CONDENSER ICE WElGHING REQUIREMENTS FOR THE SEQUOYAH NUCLEAR PLANT, UNITS 1 AND 2 (TAC NO. MA6065 AND MA6066)

Dear Mr. Scalice:

On June 24,1999, Tennessee Valley Authority (licensee of Sequoyah Nuclear Plant (SON),

Units 1 and 2) submitted an application for amendment of the Technical Specifications (TS) that would revise the TS for the weighing of ice condenser ice baskets. The changes were identified as being consistent with a companion revision to the Improved Standard TS (ISTS), as submitted by the Nuclear Energy institute (NEI) Technical Specificatii n Task Force to the U.S.

Nuclear Regulatory Commission staff on June 23,1999. The staff's review of the application has resulted in the enclosed request for additionalinformation (RAl), as provided in the

. enclosure. Due to the simultaneous nature of the review of the SON and NEl submittals, the attached RAI also include requests related to the proposed changes to the ISTS.

As discussed with your staff on October 14,1999 we understand that you plan to respond to the enclosed RAI on or about December 17,1999.

Sincerely, tght .- WCAV Ronald W. Hernan, Senior Project Manager, Section 2 Project Directorate ll Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-327 and 50-328

Enclosure:

Request for Additional Information cc w/ enclosure; See next page

REQUEST FOR ADDITIONAL INFORMATION REVISION OF ICE CONDENSER ICE WElGHING REQUIREMENTS SEQUOYAH NU_QLEAR PLANT DOCKET NOS. 50-327 and 50-328 Introduction The need for clarification of Technical Specifications (TS) for Ice Condenser Containment (ICC) plants was recognized in the letter from Mr. William Beckner, U.S. Nuclear Regulatory Commission (NRC), to Mr. James Davis, Nuclear Energy Institute, dated October 2,1998. The letter discussed issues recently identified related to licensee compliance with TS similar to the Westinghouse improved Standard Technical Specifications (ISTS) 3.6.15 " Ice Bed." These issues highlighted problems literally complying with the TS, ambiguities in the requirements, and in at least one case a TS with no apparent relationship to the design basis.

The letter from Mr. M.S. Tuckman, Duke Energy, to Mr. L.A. Reyes, NRC, dated October 21, 1998 indicated that the Ice Condenser Mini-Group (ICMG), a technical subgroup sponsored by the Westinghouse Owners Group, had recently decided to focus its efforts on the review and potential revision of ice condenser related TS in order to clarify them.  ;

Proposed Revisions to Seauovah TS 4.6.5.1.d.2 and ISTS 3.6.15 Tennessee Valley Authority (TVA) has proposed the following revisions to TS 4.6.5.1.d.2 and Bases while retaining the requirement for " Weighing a representative sample of at least 144 ice ,

baskets." l

1. Individual Basket Wei.gh1 Reouirement - The requirement to " ..and verifying that each I

basket [ emphasis added] contains at least 1071 lbs of ice" is deleted and the 1071 lb limit now  !

appears as an averaae 21-26 baskets.

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i The safety analysis provided with the application does not provide a basis for deletion of this (1071) as a minimum requirement, except to note that it would provide consistency with a proposal also made in Technical Specification Task Force (TSTF)-335 for the Standard TS (STS). The staff is concerned that deletion of a clear and specific requirement that all baskets j be above a minimum value (required for accident analysis assumptions) may be an unsupported change to the TS since it would then allow basket weights to vary over an unspecified range about the average value. As noted in Insert B of the application, the objective of the weighing and the augmented 20-basket sample is to ensure that local below-weight zones that would allow early melt-out and bypass are not permitted. Please address how these concerns would be met with the proposed deletion of a minimum basket weight requirement.

2. Auamented 20 Basket Sample - The Sequoyah Units 1 and 2 (SON) TS 4.6.5.1.d.2 has been

. reformatted by moving the augmented 20 basket sampling requirement, (which requires weighing 20 additional baskets if one basket is found < [1071] Ibs) into a " Note" which appears at the beginning of the TS. For the STS, the augmented 20-basket sampling requirement is moved from the Bases into a " Note" which appears at the beginning of the TS.

ENCLOSURE

[ l The Note refers to th; striGhtforward averaging of 21 measured values of basket weights. At the end of the Note is the phrase: ". .at a 95% confidence level." Please address the l

appropriateness of this phrase for the averaging of 21 known values of ice basket weight.

I The augmented sampling requirement has also been modified such that, of the six baskets initially weighed per bay, only one additional 20-basket sample will be taken even if more than one of the six baskets is less than the required value. Discuss whether, in this case, the ,

average value for the bay is based on 21 or all 26 known basket weights. I

3. Definition of the Reoresentative Samole - Further requests for information on this topic are held in abeyance pending the results of review of TVA's letter of October 1,1999 to the NRC.

4. Calculation of total ice weiaht - A clause is added to the SON TS 4.6.5.1.d.2 on calculation of )'

the minimum total required ice weight that clarifies that this calculation is applicable to the beginning of each operating cycle. A similar clause is added to the STS.

This proposed change appears consistent with the purpose of the surveillance; to verify that adequate ice is available for the forthcoming cycle with appropriate allowance for sublimation and weighing uncertainties.

It is understood that during an outage, as-found and as-left weight sampling is performed and  !

that, usually, several hundred baskets, including many from the crane wall rows, are serviced by having their ice weights increased. These serviced baskets would then appear to constitute a separate population from the remaining baskets since their weights may tend to be higher j and more uniform. Discuss the potential for this subset oi serviced baskets in the 144-basket i' representative sample to bias the average basket weight in an upward direction if as-left data is used. The response should also consider that the two crane-wall rows and the two containment-wall rows are represented to a greater proportional degree than the middle five rows in a .144-basket sample.

The response should also address the uncertainty in the estimate of the total amount of ice introduced by the interval since the most recent weight was obtained for the subset of frozen unweighable baskets.

5. Surveillance interval The proposed STS changed the surveillance frequency from every 9 months to every 18 months. However, the required amount of ice [1400] Ibs for each basket was not adjusted nor was an explanation provided to account for the longer sublimation period. Please discuss the basis for the acceptability of the longer interval.

. Bases

6. _SA h!! rap _tign A.l).p_wance The STS Bases SR 3.6.15.2 and the SON Bases 3/4.6.5.1 state that the average figure of (1400/1071) Ibs of ice per basket contains either a conservative allowance for ice loss through

L..

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.'sublimation which has been determined by plant specific analysis or a defined [15]% allowance.

The minimum weight figure of [2,721,600/2,082,024] Ibs of ice also contains an additional [1]%

conservative allowance to account for systematic error in weighing instruments. Provide the bases to justify the above allowance values of 15% and 1%. The response should include whether the sublimation allowance for a specific plant is based on the generic 15% value or on a plant-specific analysis (and if plant-specific, how it is determined). Also, discuss how the assumed value of 1% is reflected in the design basis and how it compares to plant operating experience.

7. Adiustment of Weiahts for Sublimation The proposed STS and SON Bases state that in the event that observed sublimation rates are equal to or lower than design prediction after three years of operation, the minimum ice basket  !

weights may be adjusted downward. The proposed specificatior?s do not address responses if sublimation is observed to be higher than predicted. It appears that the future adjustment will only be biased in a downward direction. From the meeting with the owner's group on August 11, 1999,it is understood that the adjustment of the minimum ice basket weights being addressed would require an amendment to the license and TS, which would be subject to NRC review. I Given that a license amendment is required to make such an adjustment, why is the above statement on the future adjustment needed? -

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Mr. J. A. Scalice SEQUOYAH NUCLEAR PLANT l Tennessee Valley Authority cc:

Mr. Karl W. Singer, Senior Vice President- Mr. Pedro Salas, Manager Nuclear Operations Licensing and Industry Affairs Tennessee Valley Authority - Sequoyah Nuclear Plant 6A Lookout Place Tennessee Valley Authority 1101 Market Street P.O. Box 2000 Chattanooga, TN ' 37402-2801 Soddy Daisy. TN 37379 Mr. Jack A. Bailey Mr. D. L. Koehl, Plant Manager

' Vice President . . Sequoyah Nuclear Plant Engineering & Technical Services Tennessee Valley Authority Tennessee Valley Authority P.O. Box 2000 6A Lookout Place Soddy Daisy, TN 37379 1101 Market Street -

Chattanooga, TN 37402-2801 Mr. Melvin C. Shannon Senior Resident inspector Mr. Masoud Bajestani Sequoyah Nuclear Plant Site Vice President : U.S. Nuclear Regulatory Commission Sequoyah Nuclear Plant 2600 Igou Ferry Road

' Tennessee Valley Authority Soddy Daisy, TN 37379 P.O. Box 2000 Soddy Daisy, TN 37379 Mr. Michael H, Mobley, Director TN Dept. of Environment & Conservation

. General Counsel Division of Radiological Health Tennessee Valley Authority 3rd Floor, L and C Annex ET 10H : 401 Church Street 400 West Summit Hill Drive Nashville, TN 37243-1532 Knoxville,TN 37902 County Executive Mr. N. C. Kazanas, General Manager- Hamilton County Courthouse

' Nuclear Assurance Chattanooga, TN 37402-2801 Tennessee Valley Authority SM Lookout Place

-1101 Market Street Chattanooga, TN 37402 2801

' Mr. Mark'J. Burzynski, Manager Nuclear Licensing Tennessee Valley Authority l 4X Blue Ridge .

1101 Market Street Chattanooga, TN 37402-2801