ML20236U995

Requests Addl Info Re Plant TS Change Request 356,increase in Allowable Main Steam Isolation Valve Leakage Rate

ML20236U995
Person / Time
Site:	Browns Ferry
Issue date:	07/28/1998
From:	Raghavan L NRC (Affiliation Not Assigned)
To:	Scalice J TENNESSEE VALLEY AUTHORITY
References
TAC-M94347, TAC-M94348, TAC-M94349, NUDOCS 9807310227
Download: ML20236U995 (5)

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t NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 2005tKlo01

% ..... # July 28,1998 Mr. J. A. Scalice Chief Nuclear Officer And Executive Vice President Tennessee Valley Authority 6A Lookout Place 1101 Market Street

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Chattanooga, Tennessee 77402-2801

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION REGARDING BROWNS FERRY NUCLEAR PLANT TECHNICAL SPECIFICATION CHANGE REQUEST 356, ,

INCREASE IN ALLOWABLE MAIN STEAM ISOLATION VALVE LEAKAGE 1 RATE (TAC NO. M94347, M94348, AND M4349) l

Dear Mr. Scalice:

By letter dated December 22,1995, the Tennessee Valley Authority (TVA) submitted technical specification (TS) change request No. 256, " Increase in Allowable Main Steam isolation Valve l (MSIV) Leakage Rate," and requested exemption from certain provisions of U.S. Nuclear Regulatory Commission (NRC) regulations, for the Browns Ferry Nuclear Plant (BFN) Unit's 1, )

2, and 3. TVA submitted these licensing actions as a pilot application of the revised source l term documented in NUREG-1465, " Accident Source Terms for Light-Water Nuclear Power i Plants."

The purpose of this letter is to provide you the status of the revised source term rulemaking and i our review of the BFN pilot application, and to request additionalinformation to facilitate the staff review, in a letter dated July 27,1994, the NRC staff invited the Nuclear Energy Institute (NEI) to serve as a focal point for discussions with the nuclear industry involving the revised source term at l operating reactors. In response, NEl created an industry task force and initiated a collaborative effort with the Electric Power Research Institute (EPRI). TVA is a member of NEl's Source Term Task Force and EPRI's Revised Source Term Project Utility Advisory Group. The industry proposed to develop a generic framework document that would be supplemented by /j  ;

l pilot plant applications from five utilities. The NRC staff met with the industry task force on !f several occasions. The " Generic Framework for Application of Revised Accident Source Term I to Operating Plants," TR-105909, was submitted for NRC review in November 1995. The NRC staff provided comments on 15is document to NEl by letter dated February 26,1997.

The NRC staff advised the Commission of the results ofits review of TR-105909 and of it's I approach to allowing the use of the revised accident source term in SECY-96-242, "Use of the NUREG-1465 Source Term at Operating Reactors," dated November 25,1996. In this report,

the staff described its plans to undertake a re-baselining assessment of two plants to further l evaluate the issues involved with applying the revised source term at operating plants. The staff would review the pilot plant applications following completion of the re-baselining. The Commission approved the staff's plans and directed the staff to commence rulemaking upon

! completion of the re-baselining and concurrent with the review of the pilot plant submittals.

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4 Mr. J. A. Scalice The results of the re-baselining and the rulemaking plan were submitted to the Commission on June 30,1998. The staff recognizes that the pilot utilities have expended substantial resources in preparing the submittals, and expects to complete its review of the submitt::Is in 1998.

Based on its initial review, the staff has identified some significant items as described in the enclosure, which need to be resolved before more detailed reviews can be completed.  ;

Resolving these initial items may require additional analyses on your part, and they are being l

identified early to provide lead time. The staff expects to identify additional questions when the j detailed review is performed.

Please inform us of your schedule to provide the required information.

Sincerely, 1

Original signed by I

L. Raghavan, Senior Project Manager Project Directorate 11-3 Division of Reactor Projects - 1/II Office of Nuclear Reactor Regulation Docket Nos. 50-259 50-260 50-296

Enclosure:

Request for Additional Information cc w/ enclosure: See next page DISTRIBUTION:

Docket File . . B. Clayton PUBLIC A. DeAgazio OGC

.~J. Zwolinski (A) ACRS F.Hebdon L. Plisco, Ril BFN r/f C. Miller S. LaVie L.Raghavan DOCUMENT NAME: G:\BFN\94347.RAI To receive a copy of this document, indicate in the box: "C" = Copy without attachment / enclosure "E" = Copy with attachment / enclosure "N" = No copy l 0FFICE PM:PDil-3 lE LA:PDi!-3 Ifr D:PDII-3 r 16 l l l NAME LAnghavan:cw i BClayton /%1 8 d/ Fjicinddri(11%7 ('F l DATE 07/ $ /98 07/s 4 /98 07/ 1 //98 07/ /98 07/ /98 Official Record Copy I

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Mr. J. A. Scalice BROWNS FERRY NUCLEAR PLANT Tennessee Valley Authority cc:

Senior Vice Presiderit Mr. Mark J. Burzynski, Managar Nuclear Operations Nuclear Licensing Tennessee Valley Authority Tennessee Valley Authority 6A Lookout Place 4X Blue Ridge 1101 Market Street 1101 Market Street Chattanooga, TN 37402-2801 Chattanooga, TN 37402-2801 Mr. Jack A. Bailey, Vice President Mr. Timothy E. Abney, Manager Engineering & Technical Services Licensing and Industry Affairs Tennessee Valley Authority Browns Ferry Nuclear Plant 6A Lookout Place Tennessee Valley Authority 1101 Market Street P.O. Box 2000 Chattanooga, TN 37402-2801 Decatur, AL 35609 Mr. C. M. Crane, Site Vice President Regional Administrator, Region 11 Browns Ferry Nuclear Plant U.S. Nuclear Regulatory Commission Tennessee Valley Authority 61 Forsyth Street, SW., Suite 23T85 P.O. Box 2000 Atlanta, GA 30303-3415 Decatur, AL 35609 Mr. Leonard D. Wert General Counsel Senior Resident inspector Tennessee Valley Authority U.S. Nuclear Regulatory Commission ET 10H Browns Ferry Nuclear Plant 400 West Summit Hill Drive 10833 Shaw Road Knoxville, TN 37902 Athens, AL 35611 Mr. Raul R. Baron, General Manager State Health Officer Nuclear Assurance Alabama Dept. of Public Health Tennessee Valley Authority 434 Monroe Street SM Lookout Place Montgomery, AL 36130-1701 1101 Market Street Chattanooga, TN 37402-2801 Chairman Limestone County Commission Mr< Karl W. Singer, Plant Manager 310 West Washington Street Browns Feny Nuclear Plant Athens, AL 35611 Tennessee Valley Authority P.O. Box 2000 .

Decatur, AL 35609 i

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i EROWNS FERRY NUCLEAR PLANT TECHNICAL SPECIFICATION CHANGE REQUEST 356,  !

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" INCREASE IN ALLOWABLE MAIN STEAM ISOLATION VALVE LEAKAGE RATE I (TAC NOS. M94347. M94348. AND M94349)

REQUEST FOR ADDITIONALJBFORMATION

1. The NRC will require that the results of radiological consequence assessments be reported as total effective dose equivalent (TEDE) as defined in 10 CFR Part 20.1003. Your analyses I reported whole body and thyroid doses. The analyses should consider significant )

radionuclides in each of the radior,uclide groups tabulated in Tables 3.12 and 3.13 of (

NUREG-1465. The applicable dose guidelines are:

(i) An individuallocated at any point on the boundary of the exclusion area for any l 2-hour period following the onset of the postulated fission product release, would not receive a radiation dose in excess of 25 rem TEDE.

(ii) An individual located at any point on the outer boundary of the low population zone, who is exposed to the radioactive cloud resulting from the postulated fission product release (during the entire period of its passage), would not receive a radiation dose in excess of 25 rem TEDE.

(iii) Adequate radiation protection shall be provided to perrnit access and occupancy of the control room under accident conditions without personnel receiving radiation exposures in excess of 5 rem TEDE for the duration of the accident.

Since these analyses are a first implementation of the revised source term and the revised dose calculation methodology at Bronws Ferry Nuclear Plant (BFN), and will become part of the licensing basis, the staff expects that the analyses will model the significant nuclides and dose calculations directly. Analysis approaches based on scaling results from a smaller subset of radionuclides or from whole body or thyroid results should be avoided. The implementation of the revised source te'm should be viewed as a complete replacement of, rather than an incremental change to, an earlier technology.

2. Since the dose guidelines assigned for use with the revised source term are not currently provided for in regulation, TVA should formally request an exemption under 10 CFR Part 50.11 from $100.11(a)(1) and 9100.11(a)(2), and Part 50 Appendix A, General Design Criterion-19, to substitute TEDE for the currently specified whole body and thyroid doses.

This exemption will be applicable only to dose calculations based on the revised source term.

3. The staff wi!! require that the evaluations of proposed revised source term applications consider allimpacts of the proposed application. You have proposed to increase main steam isolation valve (MSlV) allowable leakage to a total of 250 cfm for all valves from the current 11.5 cfm per valve, and performed analyses of the offsite and control room doses due to a design basis accident (DBA) loss-of-coolant accident (LOCA). The significant hazards analysir submitted with your request identifies the LOCA as the limiting case. Your l

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2 submittal needs to address the impact on other DBA analyses that could be affected by increased MSIV leakage. For example, will the increased MSIV leakage over-pressurize the main condenser during a control rod drop accident with loss of offsite power, such that credit for releases via the offgas system is no longerjustifiable?

4. Your submittal addresses the impact of the revised source term on offsite, control room, and technical support center doses. Please provide additional information addressing the impact of the revised source term on the following additional accident radiological consequences currently based on the TlD14844 source term. Extensive, detailed dose calculations may not be necessary, but a site-specific evaluetion must be performed. Conclusions regarding these impacts should be included in your no significant hazards evaluation.

Post-accident vital area access dose rates (NUREG-0737 $11.B.2)

Post-accident sampling (NUREG-0737 Sil.B.3 Equipment qualification (10 CFR Part 50.49)

5. The BFN LOCA analysis does not evaluate the dose resulting from leakage from engineered safeguards systems outside of the primary containment during a DBA LOCA. The staff requests that TVA evaluate the doses resulting from this release pathway. While this release pathway may not have been considered in the originallicensing of the plant, the revised source term has changed the composition and physical and chemical form of radionuclides in these systems. The staff expects the revised licensing basis to address the DBA LOCA release paths identified in the Standard Review Plan, and any other paths deemed significant for BFN. Please provide the r6 quested information or provide a justification supporting your position.

6. By letter dated October 1,1997, TVA submitted a technical specification change request for BFN Units 2 and 3 that would uprate the rated thermal power to 3458 MWt. The staff expects to complete its review of this amendment prior to its review of the pilot application.

The pilot application will need to be upgraded to reflect the change in the uprated reactor power. As noted above, the implementation of the revised source term should be viewed as a complete replacement of, rather than an incremental change to, an earlier technology, and the simple scaling of results to reflect the change in power should be avoided.

'7. Your submittal identified that TVA would submit additional information regarding suppression pool pH control and TVA's schedule for implementing this system. Please provide a status report on this submittal.

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