2CAN081001, Request for Additional Information, Technical Specification Changes and Analyses Relating to Use of Alternative Source Term

Request for Additional Information, Technical Specification Changes and Analyses Relating to Use of Alternative Source Term

ML102250417
Person / Time
Site:	Arkansas Nuclear
Issue date:	08/09/2010
From:	Berryman B Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
2CAN081001, TAC MD6933, TAC ME3678
Download: ML102250417 (6)

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Entergy Entergy Operations, Inc.

1448 SsR. 333 Russellville, AR 72802 Tel 479-858-3110 Brad L. Berryman Acting Vice President, Operations Arkansas Nuclear One 2CAN081 001 August 9, 2010 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555

SUBJECT:

Request for Additional Information Technical Specification Changes and Analyses Relating to Use of Alternative Source Term

'Arkansas Nuclear One, Unit 2 Docket No. 50-368 License No. NPF-6

REFERENCES:

1. Entergy letter to the NRC, dated October 5, 2007, "License Amendment Request Technical Specification Change Request Associated with Replacement of Containment Sump Buffer' (2CAN 100703)

2. Entergy letter to the NRC, dated February 19, 2008, "License Amendment Request Replacement of Containment Sump Buffer Request for Additional Information" (2CAN020802)

3. NRC letter to Entergy dated March 31, 2008, "Arkansas Nuclear One, Unit No. 2 - Issuance of Amendment RE: Technical Specifications 3.6.2.2, 'Containment Sump Buffering Agent Trisodium Phosphate (TSP)'

(TAC No. MD6933)" (2CNA030809)

4. Entergy letter to the NRC, dated March 31, 2010, "License Amendment Request Technical Specification Changes and Analyses Relating to Use of Alternative Source Term" (2CAN031001)

5. Email from Kaly Kalyanam (NRC) to Robert W. Clark (Entergy), dated May 5, 2010, "Transmission of the Acceptance Review Result to Licensee and Request for Supplemental Information (TAC No. ME3678)

6. Email from Kaly Kalyanam (NRC) to Robert W. Clark (Entergy), dated May 25, 2010, "Request for Additional Information on the AST LAR -

ME3678" Abc)

2CAN081 001 Page 2 of 3 REFERENCES (continued):

7. Entergy letter to the NRC, dated June 23, 2010, "License Amendment Request Technical Specification Changes and Analyses Relating to Use of Alternative Source Term - Supplemental Information" (2CAN061004)

8. Entergy letter to the NRC, dated June 24, 2010, "Request For Additional Information Technical Specification Changes and Analyses Relating to Use of Alternative Source Term" (2CAN061002)

9. Email from Kaly Kalyanam (NRC) to David B. Bice (Entergy), dated July 15, 2010, "Request for Additional Information on the ANO-2 LAR to implement AST - ME3678"

Dear Sir or Madam:

Entergy Operations, Inc. (Entergy) submitted a request to change the Technical Specifications (TSs) for Arkansas Nuclear One, Unit 2 (ANO-2) in support of the use of alternative source terms associated with accident offsite and control room dose consequences (Reference 4).

Supplemental information was submitted to the NRC via References 7 and 8 above.

During continued review of the material provided in Reference 4, the NRC determined that further information was required to complete the Staffs evaluation of the request (Reference 9).

Attached to this submittal is the Reference .9 Request for Additional Information (RAI) along with Entergy's response.

This letter contains no new commitments.

If you have any questions or require additional information, please contact Mark Giles at 479-858-4710.

I declare under penalty of perjury that the foregoing is true and correct. Executed on August 9, 2010.

Sincerely, BLB/dbb

Attachment:

Response to Request for Additional Information Related to the Use of Alternative Source Term (AST)

2CAN081 001 Page 3 of 3 cc: Mr. Elmo E. Collins Regional Administrator U. S. Nuclear Regulatory Commission Region IV 612 E. Lamar Blvd., Suite 400 Arlington, TX 76011-4125 NRC Senior Resident Inspector Arkansas Nuclear One P. O. Box 310 London, AR 72847 U. S. Nuclear Regulatory Commission Attn: Mr. Kaly Kalyanam MS 0-8 B1 One White Flint North 11555 Rockville Pike Rockville, MD 20852 Mr. Bernard R. Bevill Arkansas Department of Health Radiation Control Section 4815 West Markham Street Slot #30 Little Rock, AR 72205

Attachment to 2CAN081001 Response to Request for Additional Information Related to the Use of Alternative Source Term (AST)

Attachment to 2CAN081 001 Page 1 of 2 Response to Request for Additional Information Related to the Use of Alternative Source Term (AST)

1. Are any non-safety related systems and components credited in the alternate source term analyses?

No non-safety related electrical systems or components are credited in the Arkansas Nuclear One, Unit 2 (ANO-2) alternate source term (AST) analyses. Analyses requiring cool down to shutdown cooling (SDC) entry conditions credit the non-safety related Atmospheric Dump Valves (ADVs), which are designed to fail open upon loss of air and are located upstream of the Main Steam Isolation Valves (MSIVs). Steam release can then be controlled by safety-related motor-operated isolation valves located upstream of each ADV.

If so,

a. Please describe the independence (electrical and physical separation) of these systems from the safety-related systems. Also, please provide a detailed discussion on how a fault on the non-Class 1E electrical circuit will not propagate to the Class I E electrical circuit.

The safety-related ADV isolation valves are located in seismic Category 1 piping, with the classification change occurring immediately downstream of the isolation valves.

Thus, physical separation of the piping and non-safety related ADVs downstream of the isolation valves is provided by this seismic boundary. No non-Class 1 E electrical circuits are credited in the ANO-2 AST analyses. Therefore, all safety-related Class 1E circuits remain electrically independent of non-Class 1 E circuits, and faults in non-Class 1 E circuits will not propagate to Class 1 E circuits.

b. Please describe the redundancy of these systems and how these systems meet the single failure criterion.

As stated above, the ADVs fail open on loss of instrument air supply. The ADV isolation valves are capable of remote operation from the control room or associated Motor Control Center (MCC) breaker. In addition, the ADVs and ADV isolation valves are all capable of local, manual operation. Manual operation of ADVs is addressed in OP 2105.008, "Steam Dump and Bypass Control System Operations." The ANO-2 AST analyses do not credit an ADV pathway for at least 30 minutes following the initiation of an accident, providing sufficient time to take local, manual action, if required. As such, there is no credible active or passive single failure in an electrical system or active single failure in a fluid system that can prevent opening a pathway to atmosphere and allowing cool down to SDC entry conditions.

Attachment to 2CAN081 001 Page 2 of 2

c. Please describe how the operators will be notified (e.g., control room annunciators) in the event that these systems and components become inoperable.

Although there is no credible means for the ADV pathway to become inoperable, if isolation of the pathway were to occur, the operators would be alerted by a rapid increase in the associated steam generator (SG) pressure and, if no action were taken, the eventual opening of at least one Main Steam Safety Valve (MSSV).

Discharges from the MSSVs are monitored in the control room via an acoustic monitoring panel.

d. Describe seismic qualifications of these systems and components.

The ASME Class II piping in which the ADVs are installed has been analyzed and designed to withstand seismic loads in accordance with Section C-2 of NRC Regulatory Guide 1.29.

2. Are any loads being added to the Arkansas Nuclear One emergency diesel generators (EDGs)? If so, describe how the loads will impact the capability and capacity of the EDGs. Also, please describe the changes, if any, to the EDG loading sequence to support this license amendment request (LAR).

No electrical loads need to be added to the ANO-2 EDGs to support this LAR or the assumptions of the ANO-2 AST analyses.

3. Please provide a list and description of components being added to the Environmental Qualification Program (10 CFR 50.49) due to this LAR. Also, please confirm that these components are qualified for the environmental conditions they are expected to be exposed to.

No components need to be added to the Environmental Qualification Program (10 CFR 50.49) due to this LAR.