ML061430480
| ML061430480 | |
| Person / Time | |
|---|---|
| Site: | Surry  (DPR-032, DPR-037) |
| Issue date: | 05/23/2006 |
| From: | Grecheck E Virginia Electric & Power Co (VEPCO) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 06-200A | |
| Download: ML061430480 (8) | |
Text
VIRGINIA ELECTRIC AND POWER COMPANY
- RICHMOND, VIRGINIA 23261 1 OCFR50.92 May 23, 2006 U S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 Serial No.
06-200A NL&OS/GDM R1 Docket Nos.
50-280 License Nos. DPR-32 50-281 DPR-37 VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNITS 1 AND 2 PROPOSED TECHNICAL SPECIFICATIONS CHANGE REDEFINITION OF EXCLUSION AREA BOUNDARY SUPPLEMENTAL RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION By letter dated April 7, 2006 (Serial No.06-200), Virginia Electric and Power Company (Dominion) responded to an NRC request for additional information associated with a proposed Technical Specifications (TS) change to redefine the exclusion area boundary (EAB) as the site boundary in the TS. In that letter, we stated that the site boundary dimensions indicated on the Surry site plan drawing were being validated to ensure accurate distances were being used for determining the source-to-receptor distances, and that Dominion would provide recalculated EAB X/Qs and minimum sector distances based on RG 1.I45 guidance by May 31, 2006, to facilitate NRC review of the proposed TS change. These two activities have been completed, and the results are provided in the attachment.
If you have any questions or require additional information regarding this TS change request, please contact Mr. Gary Miller at (804) 273-2771.
Very truly yours, E. S. Grecheck Vice Pres'ident - Nuclear Support Services Attach men t Commitments made in this letter: None
Serial No. 06-200A Docket Nos. 50-280, 281 Page 2 of 2 cc:
U.S. Nuclear Regulatory Commission Region II Sam Nunn Atlanta Federal Center 61 Forsyth Street, SW Suite 23T85 Atlanta, Georgia 30303 Mr. N. P. Garrett NRC Senior Resident Inspector Surry Power Station Mr. S. R. Monarque NRC Project Manager U. S. Nuclear Regulatory Commission One White Flint North 11 555 Rockville Pike Mail Stop 8-H12 Rolckville, MD 20852 Colmmissioner Bureau of Radiological Health 15100 East Main Street Suite 240 Richmond, VA 23218
Serial No. 06-200A Docket Nos. 50-280, 281 Supplemental RAI Response - Redefinition of the EAB COMMONWEALTH OF VIRGINIA
)
1 COUNTY OF HENRICO
)
The foregoing document was acknowledged before me, in and for the County and Commonwealth aforesaid, today by Eugene S. Grecheck, who is the Vice President -
Nuclear Support Services of Virginia Electric and Power Company. He has affirmed before me that he is duly authorized to execute and file the forgoing document in behalf of that Company, and that the statements in the document are true and correct to the best of his knowledge, information, and belief.
Acknowledged before me this 2006.
My Commission Expires:L 3r. aoo6, Notary Public (SEAL)
Serial No. 06-200A Docket Nos. 50-280, 281 Attachment ProDosed Technical SDecifications Chanae Redefinition of Exclusion Area Boundary SuDDlemental ResDonse to Reauest for Additional Information By letter dated September 13, 2005 (Serial No.05-601), Virginia Electric and Power Company (Dominion) submitted proposed license amendments for Surry Power Station, Unit Nos. 1 and 2.
These proposed changes would redefine the exclusion area boundary (EAB) as the site boundary in Technical Specification 5.1, Site. In a letter dated February 22, 2006, the NRC requested additional information to facilitate their review. Specifically, the NRC requested: 1) confirmation of Dominions authority to control various activities associated with the redefined EAB, and 2) justification for why Regulatory Guide (RG) 1.145 methodology was not used to determine the minimum distances from potential release points to the EAB in each wind direction. By letter dated April 7, 2006 (Serial No.06-200), Dominion responded to the NRC request and addressed item 1 in total and item 2 in part. In that letter, we stated that the site boundary dimensions indicated on the Surry site plan drawing were being validated to ensure accurate distances were being used for determining the source-to-receptor distances;, and that recalculated EAB X/Qs and minimum sector distances would be provided based on RG 1.145 guidance.
Consequently, new WQ values have been prepared that are consistent with the RG 1.145 guidance. Following the guidance, the minimum distance from each release point to the EAB within a 45-degree sector centered on each compass direction was determined. In general, the minimum EAB distance decreased slightly from what was determined previously using a 22.5-degree wide sector criterion.
In addition to selecting minimum distances in accordance with the RG 1.145 guidance, the Surry site plan drawing was revised to adjust the position of several segments of the property line in order to correct the conversion from a property survey to a drawing. In general, the adjustment slightly increased distances to the EAB in the North, South, and West, but decreased distances in the Northeast and Southeast. Figure 1 is the revised site map that was used to determine the minimum distances from the potential source release locations to the closest point on the site boundary for each wind sector based on the RG 1.145 guidance. The attached Figure 1 replaces the Figure 1 included with our letter dated September 13, 2005.
Table 1 contains the minimum distances for each wind sector from the various source release locations to the site boundary based on the RG 1.145 guidance. Table 1 below replaces the Table 1 included in our September 13, 2005 submittal. The minimum distance values in Table 1 were determined in the same manner as described in that letter. In addition to the source release locations included in the September 13, 2005 letter, Table 1 includes minimum distance information from the Unit 1 and Unit 2 steam generator (SG) power operated relief valves (PORVs). With the addition of the distance data for the Unit 1 and Unit 2 SG PORVs, the distance values in Table 1 are the minimum distances from the potential source release locations for the Loss of Coolant Accident (LOCA), Fuel Handling Accident (FHA), Steam Generator Tube Rupture Page 1 of 4
Serial No. 06-200A Docket Nos. 50-280, 281 Attachment (SGTR), Main Steam Line Break (MSLB) and Locked Rotor Accident (LRA) to the site boundary in each wind sector.
The new EAB distances from Table 1 were used to modify the PAVAN input decks submitted in our September 13, 2005 submittal. Table 2 contains the results of the PAVAN runs completed using the seven sets of source-to-receptor distances from Table 1, and joint frequency distribution tables based on meteorological data from 1994-1998 that were also included in the September 13, 2005 letter. By explicitly modeling the SGTR, MSLB and LRA source release locations, the qualitative argument in our September 13, 2005 submittal regarding the applicability of the limiting X/Q to those source release locations is replaced by quantitative results that support the same conclusion.
In Table 2, the worst-case 0-2 hour WQ (1.76E-03 sec/m3) at the redefined EAB occurred in the north direction as a result of release from the Unit 1 Containment. In comparison to the value of 1.79E-03 sec/m3 from our September 13, 2005 letter, the limiting result from Table 2 indicates that there was no significant impact by not initially using the guidance of RG 1.145 to determine the minimum distance to the site boundary.
It is intended that the highest valued 0-2 hour X/Q in Table 2 (1.76E-03 sec/m3) will be used in a11 future EAB dose assessments as an approved change to an element of a methodology. Pursuant to 10 CFR 50.59, prior NRC review and approval of this change in the EAB WQ is required because the new value will result in a significant increase in margin to1 the limit by changing an element of the methodology. The dose consequence accident analyses were not submitted with this change because the EAB results listed in the UFSAR are conservative with respect to consequences that would be calculated using this new EAB WQ.
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Serial No. 06-200A Docket Nos. 50-280, 281 Attachment Each Source !?e!esse LocctIo!?)
Sector Unit 2 PORVs considered for Unit 1 Unit 2 Ventilation Vent Auxiliary Building Auxiliary Building Unit Sector minimum Containment Containment No. 2 East - louver West - louver distance (degrees)
(ft)
(m)
(ft)
( 4 (ft)
(m)
(ft)
(m)
(ft)
(m)
(ft)
(m)
(ft)
(m)
N 337.5 - 22.5 1642 500 1740 530 1721 525 1762 537 1735 529 1715 523 1787 545 NNE 0 - 45 1642 500 1740 530 1721 525 1762 537 1735 529 1715 523 1787 545 NE 22.5 - 67.5 1683 513 1760 536 1759 536 1808 551 1778 542 1757 536 1787 545 ENE 45 - 90 2005 611 1880 573 1945 593 1991 607 2077 633 2089 637 1938 591 E
67.5 - 112.5 2064 629 1994 608 1945 593 2063 629 2077 633 2117 645 2162 659 ES E 90 - 135 5060 1542 4941 1506 4993 1522 4942 1506 5009 1527 5066 1544 4881 1488 SE 112.5 - 157.5 4091 1247 3942 1202 3973 1211 3923 1196 3982 1214 4031 1229 3883 1184 SSE I35 - 180 2578 786 2670 814 2615 797 2540 774 2513 766 2481 756 2577 785 S
157.5 - 202.5 2052 625 2127 648 2079 634 2028 618 1999 609 1977 603 2046 624 ssw 180 - 225 1953 595 2019 615 1979 603 1929 588 1907 581 1878 572 1944 593 SW 202.5 - 247.5 1953 595 2019 615 1979 603 1929 588 1907 581 1878 572 1944 593 wsw 225 - 270 1953 595 2019 615 1979 603 1929 588 1907 581 1878 572 1944 593
~
W 247.5 - 292.5 2111 643 2250 686 2209 673 2142 653 2119 646 2096 639 2163 659 WNW 270 - 315 2087 636 2383 726 2279 695 2282 696 2183 665 2093 638 2360 719 NW 292.5 - 337.5 2087 636 2122 647 2132 650 2202 671 2183 665 2093 638 2360 719 NNW 315 - 0 1662 507 1740 530 1741 531 1780 543 1763 537 1738 530 1812 552 The distances in Table 1 are approximations, based on a computer-aided design (CAD) drawing. The distance of Page 3 of 4
Serial No. 06-200A Docket Nos. 50-280, 281 Attachment Table 2: PAVAN Results (Limiting 0.5% Sector-Dependent X/Q Values,I 994-98 Meteorological Data)
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