ML032250692
| ML032250692 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 08/05/2003 |
| From: | Rosalyn Jones Duke Energy Corp, Duke Power Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML032250692 (9) | |
Text
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A Duke Energy Company R. A. JONES Vice President Duke Power 29672 / Oconee Nuclear Site 7800 Rochester Highway Seneca, SC 29672 864 885 3158 864 885 3564 fax August 5, 2003 U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Attention: Document Control Desk
Subject:
Oconee Nuclear Station Docket Numbers 50-269, 270, and 287 Supplement 2 to License Amendment Request associated with the Passive Low Pressure Injection Cross Connect Modification Technical Specification Change (TSC) Number 2003-02 In a submittal dated March 20, 2003 Duke proposed to amend Appendix A, Technical Specifications, for Facility Operating Licenses DPR-38, DPR-47 and DPR-55 for Oconee Nuclear Station, Units 1, 2, and 3 to support installation of a passive LPI Cross Connect inside containment.
On April 23, May 9, May 15, May 20, June 10 and June 19, 2003, Duke received questions from the NRC related to the LPI Cross Connect License Amendment Request.
Duke provided responses to all questions except one (RAI-12) by letter dated July 22, 2003.
The Attachment provides Duke's response to the remaining question.
Pursuant to 10 CFR 50.91, a copy of this proposed license amendment is being sent to the State of South Carolina.
www. duke-energy. corn
-w U. S. Nuclear Regulatory Commission August 5, 2003 Page 2 of 5 If there are any qxuestions regarding this submittal, please contact Boyd Shingleton at (864) 885-4716.
Very R. A. ;
Oconee
- Vice President ear Site
4' U. S. Nuclear Regulatory Commission August 5, 2003 Page 3 of 5 cc:
Mr. L. N. Olshan, Project Manager Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Mail Stop 0-14 H25 Washington, D. C. 20555 Mr. L. A. Reyes, Regional Administrator U. S. Nuclear Regulatory Commission -
Region II Atlanta Federal Center 61 Forsyth St., SW, Suite 23T85 Atlanta, Georgia 30303 Mr. M. C. Shannon Senior Resident Inspector Oconee Nuclear Station Mr. Henry Porter, Director Division of Radioactive Waste Management Bureau of Land and Waste Management Department of Health & Environmental Control 2600 Bull Street Columbia, SC 29201
U. S. Nuclear Regulatory Commission August 5, 2003 Page 4 of 5 R. A. Jones, being duly sworn, states that he is Vice President, Oconee Nuclear Site, Duke Energy Corporation, that he is authorized on the part of said Company to sign and file with the U. S. Nuclear Regulatory Commission this revision to the Renewed Facility Operating License Nos.
DPR-38, DPR-47, DPR-55; and that all the statements and matters set forth herein are true and correct to the best of his know ge.
R. A. J Buis Vice President Oconee Nu e r Site scribd and sworn to before me this a
day of J 2003 otary Public My Commission Expires:
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August 5, 2003 Attachment - Page 1 Attachment RAI-12 Response Related to Oconee Amendment Request RAI-12: Due to the recent V.C. Summer event of primary water stress corrosion cracking (PWSCC), the staff has a general concern over PWSCC and other unidentified degradation mechanisms on proposed LBB piping. As a result, the staff requested recent LBB applicants to perform a sensitivity study using a crack morphology (surface roughness and number of turns) characteristic of transgranular stress corrosion crack (TGSCC). Information contained in NRC NUREG/CR-6443, Deterministic and Probabilistic Evaluations for Uncertainty in Pipe Fracture Parameters In Leak-Before-Break and In-Service Flaw Evaluations," may be useful. You only need to perform this analysis for SMAW weld at location 2 having a margin of 2.4 on flaw sizes. The staff understands that using the suggested TGSCC crack morphology will reduce the margin significantly. The purpose is to know how much margin (10 for leakage, and 2 for flaw sizes) that the piping still has should a TGSCC occur.
Answer: The margin quoted in the RAI question appears to be a typographical error.
The FANP LBB report provides a margin of 2.8 on flaw sizes for SMAW weld at location 2.
NRC NUREG/CR-6443, uDeterministic and Probabilistic Evaluations for Uncertainty in Pipe Fracture Parameters in Leak-Before-Break and In-Service Flaw Evaluations,"
describes different default crack morphology parameters used in three different leak rate analysis codes. In the NUREG, the largest default surface roughness Is 3150 pin and largest default number of 900 turns is 152/in. These parameters, as well as a range of parameters both lower and higher were used to create a test matrix. The range of parameters is listed in Table 1.
Table 1. Crack Morphology Parameters Surface Roughness (J of 90 Turns (#in) 196.80 0
2008.44 1
3150.00 10 3820.08 35 6537.54 65 9255.00 152 21185.38 250 572
_ _ _ _ _ __ 1162 The critical flaw size in LBB topical report is 9.74 inches. This flaw size corresponds to a margin of flaw size of 1. The leakage size crack for this critical flaw is 19.48 Inches. For the SMAW weld at location 2 with surface roughness of 196.8 gin and 0 turns, the leakage flaw size is 3.435 in, corresponding to a margin of 2.8 on flaw size. For margins
J-August 5, 2003 Attachment - Page 2 on flaw size of 2 and 1.5, the leakage size cracks are 9.74 and 12.99 inches, respectively.
The two highest surface roughness values - 9255 and 21185.38 pin - are the crack opening displacements (COD) for leakage size cracks of 9.74 and 12.99 Inches, respectively.
57 tests (utilizing FANP's program KRAKFLOW) were run using combinations of the surface roughness and number of turn values in Table 1. It was decided to maintain the margin of 10 on leakage. The resulting leakage size crack lengths and margin on flaw size were determined for the various permutations of crack morphology. Table 2 lists the leakage size cracks and Table 3 lists the corresponding margins on flaw size.
Figures 1 shows the leakage size crack lengths vs. number of 900 turns, while Figure 2 shows the margin on flaw size vs. number of 900 turns.
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August 5, 2003 Attachment - Page 3 Table 2. Leakage Size Crack Lengths
~Surface I
Number of 90 Turns (#Win)
Roughness(;dn) 0 1
10 1 35 1 65 1 152 l 250 1 572 1 1162 196.80 6.87 7.249 8.826 9.821 10.423 11.313 11.897 12.990 2008.44 7.929 8.236 9.720 10.843 11.482 12.473 13.098 14.302 3150.00 8.198 8.528 10.037 N/A**
N/A*
12.753 13.418 14.645 3820.08 8.327 N/A**
10.124 11.232 11.881 12.889 13.564 14.802 6537.54 8.753 9.131 10.384 11.604 12.286 13.332 14.014 15.270 9255.00 9.0921 9A.99 10.798 11.899 12.585 1 13.640 14.347 15.6261 21185.38 10.112 10.415 11.618 13.004 13.790 14.604 15.396 16.556 17.645
- Note: KRAKFLO would not converge for these combinations of crack morphology parameters Figure 1. Comparison of Leakage Size Cracks for Various Crack Morphology Parameters 15 13-us
) S f 0
~~~~~~~~~~~~roughness (micro Inch wl Nj1e=168 7
5 0
50 100 150 200 NUMBER OF 900 TURNS 250
August 5,2003 Attachment - Page 4
. Table 3. Margin on Flaw Size -
Surface l
Number of 90 Turns (#fin)
Roughness (in) l 1
0 10 35 l 65 l 152 l 250 572 11162 196.80 2.84 2.687 2.207 1.983 1.869 1.722 1.637 1.500 2008.44 2.457 2.365 2.004 1.796 1.697 1.562 1.487 1.362 3150.00 2.376 2.284 1.941 NIA**
N/A**
1.527 1.452 1.330 3820.08 2.339 N/A**
1.924 1.734 1.640 1.511 1.436 1.316 6537.54 2.226 2.133 1.876 1.679 1.585 1.461 1.390 1.276 9255.00 2.143 2.051 1.804 1.637 1.548 1.428 1.358 1.247 21185.38 1.926 1.870 1.677 1.498 1.413 1.334 1265 1.177 1.104
- Note: KRAKFLO would not converge for these combinations of crack morphology parameters Figure 2. Comparison of Flaw Size Margin for Various Crack Morphology Parameters 3
2.8 toughness (mic
= 196.80 2.6
=2008.44 3150 2.4
-w--E = 3820.08 N
= 6537.54 2.2 9255 z
0
~1.8 1.6-1.4-1.2-0 50 100 150 200 NUMBER OF 900 TURNS 250
August 5, 2003 Attachment - Page 5 The leakage size cracks In Table 2 all have a margin on leakage of 10. For the NUREG/CR-6443 highest default crack morphology parameters for surface roughness of 3150 pin and largest default number of 900 turns of 152/in, the margin on flaw size is 1.527. Using the range of surface roughness and number of turns specified above, it was not possible to obtain a margin less than 1.104. The parameters that would be required to obtain a margin of 1.0 or less are considered highly unlikely, even for a TGSCC type crack.