1CAN090802, Response to Request for Additional Information Regarding Technical Specification Changes and Analyses Relating to Use of Alternate Source Term

Response to Request for Additional Information Regarding Technical Specification Changes and Analyses Relating to Use of Alternate Source Term

ML082620702
Person / Time
Site:	Arkansas Nuclear
Issue date:	09/18/2008
From:	Mitchell T Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
1CAN090802, TAC MD7178
Download: ML082620702 (9)

Text

Entergy Operations, Inc.

1448 S.R. 333 Russellville, AR 72802 Tel 479-858-3110 Timothy G. Mitchell Vice President, Operations Arkansas Nuclear One 1CAN090802 September 18, 2008 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555

SUBJECT:

Response to Request for Additional Information Regarding Technical Specification Changes and Analyses Relating to Use of Alternate Source Term Arkansas Nuclear One, Unit 1 Docket No. 50-313 License No. DPR-51

REFERENCE:

1. Entergy letter dated October 22, 2007, License Amendment Request: Technical Specification Changes and Analyses Relating to Use of Alternate Source Term (1CAN100703) (TAC NO: MD7178)

2. Entergy letter dated March 13, 2008, Supplement to Amendment Request: Technical Specification Changes and Analyses Relating to Use of Alternate Source Term (1CAN030803) (TAC NO: MD7178)

3. Entergy letter dated April 3, 2008, Supplement to Amendment Request: Technical Specification Changes and Analyses Relating to Use of Alternate Source Term (1CAN040802) (TAC NO: MD7178)

4. NRC letter dated August 13, 2008, Arkansas Nuclear One, Unit 1 -

Re: Request for Additional Information Regarding Application of the Alternative Source Term (TAC No. MD7178)

5. Entergy letter dated August 14, 2008, Response to Request for Additional Information Regarding Technical Specification Changes and Analyses Relating to Use of Alternate Source Term (TAC No.

MD7178)

Dear Sir or Madam:

By letter (Reference 1), Entergy Operations, Inc. (Entergy) proposed a change to the Arkansas Nuclear One, Unit 1 (ANO-1) Technical Specifications (TSs) to support adoption and use of Alternate Source Term (AST) in the ANO-1 Safety Analyses.

1CAN090802 Page 2 of 3 On September 3, 2008, Entergy was notified of a request for additional information (RAI) with regard to the subject letter (Reference 1). Attachment 1 contains the Entergy responses to the RAI. contains an updated table and figure. Note that Table 1.8.1-2 was also resubmitted (unchanged) as part of a separate response to NRC requests in Entergy letter submitted August 14, 2008, (Reference 5, Attachment 2, Page 11 of 28).

There are no technical changes proposed that impact the original no significant hazards consideration included in Reference 1. There are no new commitments contained in this letter.

If you have any questions or require additional information, please contact Dale James at 479-858-4619.

I declare under penalty of perjury that the foregoing is true and correct. Executed on September 18, 2008.

Sincerely, TGM/dbb Attachments:

1. Response to Request for Additional Information Regarding Technical Specification Changes and Analyses Relating to Use of Alternate Source Term

2. Updated Analysis Input Table and Figure

1CAN090802 Page 3 of 3 cc: Mr. Elmo E. Collins Regional Administrator U. S. Nuclear Regulatory Commission Region IV 612 Lamar Blvd., Suite 400 Arlington, TX 76011-8064 NRC Senior Resident Inspector Arkansas Nuclear One P. O. Box 310 London, AR 72847 U. S. Nuclear Regulatory Commission Attn: Mr. Alan B. Wang MS O-7 D1 Washington, DC 20555-0001 Mr. Bernard R. Bevill Director Division of Radiation Control and Emergency Management Arkansas Department of Health & Human Services P.O. Box 1437 Slot H-30 Little Rock, AR 72203-1437

Attachment 1 To 1CAN090802 Response to Request for Additional Information Regarding Technical Specification Changes and Analyses Relating to Use of Alternate Source Term to 1CAN090802 Page 1 of 2 Response to Request for Additional Information Regarding Technical Specification Changes and Analyses Relating to Use of Alternate Source Term The U.S. Nuclear Regulatory Commission (NRC) staff determined that additional information is needed to complete its review of the license amendment request for Alternate Source Term (AST) for Arkansas Nuclear One, Unit 1 (ANO-1), sent by letter dated October 22, 2007, as supplemented by letter dated April 3, 2008 from Entergy Operations Inc. (Entergy or licensee).

The following questions constitute the NRC request for additional information for the atmospheric dispersion portion of the review. The following questions are related to Table 1.8.1-2 of Attachment 2 to the April 3, 2008 letter.

1. Based upon a random comparison check with information provided in drawings in Attachment 2, there appears to be an inconsistency among a few of the distances and/or directions for the penetration room ventilation system exhaust and containment release points to the north and south control room air intakes with respect to values presented in Table 1.8.1-2, the related text in Section 1.8, Atmospheric Dispersion (/Q) Factors, and inputs used in the ARCON96 computer calculations. Please confirm that the values for all of the release points listed in Table 1.8.1-2, discussed in the related Section 1.8 text and shown in plant drawings, and input into the ARCON96 calculations are correct or make appropriate revisions as needed. If revisions are needed, please identify the revisions and discuss the impact of the revisions on the calculated dose to the control room operator.

Response

The values for all release points listed in Table 1.8.1-2 were re-calculated via hand calculations and found to be accurate with the following exceptions:

Receptor Release Re-Calculated Distance Re-Calculated Release Point Point Ht (m) Release Ht (m) (m) Distance (m)

ADV N CR Intake 32.61 32.76 N/A Same ADV S CR Intake 32.61 32.76 N/A Same MSSV N CR Intake N/A Same 20.62 21.04 MSSV S CR Intake N/A Same 15.26 15.83 Fuel Handling 54.53 54.71 N/A Same N CR Intake Area Fuel Handling 54.53 54.71 N/A Same S CR Intake Area In each of the above cases, the difference is insignificant and appears to be due to the analysts rounding method. In addition, though insignificant, the values used in the X/Q calculations bound the re-calculated values, that is, values that place the receptors closer to the release points are used. Therefore, the values used in the ARCON96 computer calculations, which were verified to be consistent with the values reported in Table 1.8.1-2, have not been revised and no changes to the previously reported and used X/Q values are proposed.

to 1CAN090802 Page 2 of 2 The discussion provided in Section 1.8 was also reviewed and found to require the following corrections with respect to the locations of the intake penthouses: The intake penthouse VPH-1 is actually centered approximately 10 33/4 east (not west) of the auxiliary building support column designator 5.9 and 79 71/2 north (not south) of the auxiliary building support column designator A. The intake penthouse VPH-2 is also centered approximately 10 33/4 east of the auxiliary building support column designator 5.9.

VPH-2 was correctly identified as being centered 13 6 south of the auxiliary building support column designator E.

During the re-review of Section 1.8 and its associated tables and figures, it was determined that Figure 1.8.1-7 was incorrectly drawn and could lead to confusion with regard to the locations of VPH-1 and VPH-2 with respect to the penetration room ventilation system release point. The figure has been re-drawn and is attached to this response (see Attachment 2). With respect to the containment release point, please see the response to Question #2 below.

2. It appears that the containment release height value given in Table 1.8.1.-2 is with respect to the auxiliary building whereas heights for the other release points are with respect to plant grade. If this is the case, please revise Table 1.8.1-2 to use plant grade as the single reference and move the value of 4.22 meters currently in Table 1.8.1-2 to the related footnote discussion following the table. NRC staff acknowledges that a value of 29.4 meters was used in the ARCON96 computer calculation and that this appears to be the release height using plant grade as the reference.

Response

Table 1.8.1-2 has been revised as suggested and is attached to this response (see Attachment 2). It should be noted that the 29.4 meter release height corresponds to the height of the auxiliary building roof, which conservatively provides the shortest distance between the containment building surface and the intake penthouses. To calculate the distance and direction of the containment release points relative to the penthouses, the information provided in Figure 1.8.1-6 is best used.

Attachment 2 To 1CAN090802 Updated Analysis Input Table and Figure to 1CAN090802 Page 1 of 2 Table 1.8.1-2 Release-Receptor Combination Parameters (Basis: Plant Design Drawings)

Receptor Direction Receptor Release Distance Release Point Height with respect Point Height (m) (m)

(m) to true north ADV N CR Intake 32.61(1) 28.62 33.51 212 ADV S CR Intake 32.61(1) 28.65 23.67 229 MSSV N CR Intake 30.78 28.62 20.62(1) 228 MSSV S CR Intake 30.78 28.65 15.26(1) 266 Steam Pipe N CR Intake 19.58 28.62 35.01 206 Steam Pipe S CR Intake 19.58 28.65 24.17 219 Fuel Handling Area N CR Intake 54.53(1) 28.62 32.52 218 Fuel Handling Area S CR Intake 54.53(1) 28.65 23.77 237 PRVS Exhaust N CR Intake 55.63 28.62 19.61 258 PRVS Exhaust S CR Intake 55.63 28.65 21.09 295 Containment N CR Intake 29.41(2) 28.62 20.91 246 Containment S CR Intake 29.41(2) 28.65 17.6 264 (1) Conservative value used.

(2) Containment assumed to be a diffuse area with a height of 83 feet (above the auxiliary building). The diffuse area width (containment diameter) is 123.5 feet.

to 1CAN090802 Page 2 of 2 N

61 9 EL 533 6 EL 536 6 VPH-2 Unit 1 VPH-1 Containment 4

EL 448 0 E 28.7 EL 450 6 13.15 Unit 1 Aux. Bldg.

EL 447 10-15/16 62.97 Unit 2 Aux. Bldg.

EL 354 0 Figure 1.8.1-7 Arrangement of Unit 1 penetration room ventilation exhaust relative to VPH-1 and VPH-2 (centerline of ANO-1&2 auxiliary buildings run north-south; unit 2 is directly north of unit 1)