DCL-13-021, Areva Calculation 32-9200291-000, DCPP Unit 2 - Evaluation of Laminar Indications in Pressurizer Nozzles (Non-Proprietary)
| ML13078A291 | |
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|---|---|
| Site: |  |
| Issue date: | 03/05/2013 |
| From: | Riordan T AREVA NP |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
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| References | |
| DCL-13-021 32-9200291-000 | |
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Text
Enclosures 3 and 4 contain Proprietary Information
-Withhold Under 10 CFR 2.390 Enclosure 7 PG&E Letter DCL-13-021 AREVA Calculation
- 32-9200291-000, "DCPP Unit 2 -Evaluation of Laminar Indications in Pressurizer Nozzles (Non-Proprietary)" Enclosures 3 and 4 contain Proprietary Information When separated from Enclosures 3 and 4 , this document is decontrolled.
0402-01-F01 (Rev. 017 , 11/19/12)
A AREVA CALCULATION
SUMMARY
SHEET (CSS) Document No. 32 -9200291 -000 Safety Related: Yes D No Title DCPP Unit 2 -Evaluation of Laminar Indications on Pressurizer Nozzles (Non-Proprietary)
PURPOSE AND
SUMMARY
OF RESULTS: AREVA NP Inc. proprietary information in the document are indicated by pairs of braces "[ ]". PURPOSE: Reference
[1] provides the results of inspections performed on several Pressurizer (PZR) Nozzles at Diablo Canyon Power Plant (DCPP) Unit 2. The data shows rejectable laminar indications on PZR Safety Nozzle A, Safety Nozzle B , and the Spray Nozzle. The laminar indications are typically located around the circumference of the nozzle near the interface of the NiCrFe Alloy 52M weld overlay (WOL) and the nozzle. Per the Relief Request (Reference
[2] approved by Reference
[3]) Enclosure 2, Attachment 1, Paragraph 3(a)(3)(a), laminar flaws shall meet the acceptance standards of Table IWB-3514-3.
This document addresses the requirements of Table IWB-3514-3; other requirements listed in Paragraph 3(a)(3)(a) are addressed elsewhere.
Reference
[3] section 4.6, item 3 states that the applicable Section XI code year is 2004 with addenda through 2005 (Reference
[4]). The purpose of this document is to evaluate if the laminar indications detected on PZR Safety Nozzle A, Safety Nozzle B, and the Spray Nozzle meet the acceptance standards Table IWB-3514-3 of Section XI of the ASME Boiler and Pressure Vessel Code (Reference
[4]). Additionally, this document will use a conservative methodology to show that the interface length between the WOL and the nozzle base metal is sufficient to transfer load back to the base metal without exceeding the allowable primary shear stress limits of Section III of the ASME code (Reference
[5]).
SUMMARY
OF RESULTS: The laminar indications detected during inservice inspection of PZR Safety Nozzle A, Safety Nozzle B, and the Spray Nozzle at DCPP Unit 2 meet the acceptance standards of Table IWB-3514-3 of Section XI of the ASME Code (Reference
[4]). The WOL on each nozzle has been verified to have sufficient length to transfer loads back to the base metal without exceeding allowable primary shear stresses of NB-3227.2 of Reference
[5]. THE FOLLOWING COMPUTER CODES HAVE BEEN USED IN THIS DOCUMENT:
CODENERSION/REV CODENERSION/REV N/A THE DOCUMENT CONTAINS ASSUMPTIONS THAT SHALL BE VERIFIED PRIOR TO USE DYES [g] NO Page 1 of 14 A AREVA 0402-01-F01 (Rev. 017, 11/19/12)
Document No. 32-9200291-000 DCPP Unit 2 .. Evaluation of Laminar IndicatIons on Pressurizer Nozzles (Non-Proprietary)
Review Method: IZI Design Review (Detailed Check) D Alternate Calculation Signature Block P/R/A Name and Title and (printed or typed) Signature LP/LR Date Tom Riordan P Engineer ill Pei-Yuan Cheng R 3/r;l3 EngineerllI Tim Wiger A 0/0/,3 Engineering Manager .-
r -Note: PIRIA designates Preparer (P), Reviewer (R), Approver (A); LPILR desigriates Lead Preparer (LP), Lead Reviewer (LR) Pages/Sections Prepared/Reviewed/Approved All All All Project Manager Approval of Customer References (N/A if not applicable)
Name Title (printed or typed) (printed or typed) Signature Date N/A Mentoring Information (not required per 0402-01) Name Title Mentor to: (printed or typed) (printed or typed) (P/R) Signature Date N/A Page 2 A AREVA Revision No. 000 0402-01-F01 (Rev. 017,11/19/12)
Document No. 32-9200291-000 DCPP Unit 2 -Evaluation of Laminar Indications on Pressuri z er No zz les (Non-Proprietary)
Record of Revision Pages/Sections/Parag r aphs Changed. Brief Description
/ Change Authorization All Initial Release Page 3 A AREVA Document No. 32-9200291-000 DCPP Unit 2 -Evaluation of Laminar Indications on Pressurizer Nozzles (Non-Proprietary)
Table of Contents Page SIGNATURE BLOCK ................
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....................................................................................
2 RECORD OF REVISION .......................................................................................................................
3 LIST OF TABLES ..............................................................................................................
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5 LIST OF FIGURES ............................. ..................................................................................................
5 1.0 PURPOSE ...............................
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......................................................
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6 2.0 ANALYTICAL METHODOLOGy
.................................................................................................
6 2.1 Indication Area Evaluation
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6 2.2 Overlay Length Evaluation
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6 2.2.1 Overlay Length Evaluation Conservatisms
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.... 7 3.0 ASSUMPTIONS
.........................................................................................................................
8 4.0 CALCULATIONS
................................................................................................
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8 4.1 PZR Safety Nozzle A .......................................
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8 4.2 PZR Safety Nozzle B .........................................................................................................................
9 4.3 PZR Spray Nozzle .................
................................................................................
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..... 10 4.4 Overlay Length Calculations
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11
5.0 CONCLUSION
S
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14
6.0 REFERENCES
..................................................................................................
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14 Page 4 A AREVA Document No. 32-9200291-000 DCPP Unit 2 -Evaluation of Laminar Indications on Pressurizer Nozzles (Non-Proprietary)
List of T a bles Page Table 4-1: Required WOL Length for Safety Nozzles ..........................................................................
11 Table 4-2: Required WOL Length for Spray Nozzle ............................................................................
12 Table 4-3: WOL Length Verification
...............
.....................................................................................
13 List of Figures Page Figure 4-1: WIB-368 Overlay Rollout Safety Nozzle "A" (Reference
[1]) ................................................
8 Figure 4-2: WIB-423 Overlay Rollout Safety Nozzle "B" (Reference
[1]) ................................................
9 Figure 4-3: WIB-345 Overlay Rollout Spray Nozzle (Reference
[1]) ....................................................
10 Figure 4-4: Safety Nozzle Weld Overlay Length (Reference
[6]) .........................................................
12 Figure 4-5: Spray Nozzle Weld Overlay Length (Reference
[9]) ..........................................................
13 Page 5 A AREVA Document No. 32-9200291-000 DCPP Unit 2 -Evaluation of Laminar Indications on Pressurizer Nozzles (Non-Proprietary) 1.0 PURPOSE Reference
[1] provides the results of inspections performed on several Pressurizer (PZR) Nozzles at Diablo Canyon Power Plant (DCPP) Unit 2. The data shows rejectable laminar indications on PZR Safety Nozzle A, Safety Nozzle B, and the Spray Nozzle. The laminar indications are typically located around the circumference of the nozzle near the interface of the NiCrFe Alloy 52M weld overlay (WOL) and the nozzle. Per the Relief Request (Reference
[2] approved by Reference
[3]) Enclosure 2, Attachment 1, Paragraph 3(a)(3)(a), laminar flaws shall meet the acceptance standards of Table IWB-3514-3.
This document addresses the requirements of Table IWB-3514-3; other requirements listed in Paragraph 3(a)(3)(a) are addressed elsewhere.
Reference
[3] Section 4.6, item 3 states that the applicable Section XI code year is 2004 with addenda through 2005 (Reference
[4]). The purpose of this document is to evaluate if the laminar indications detected on PZR Safety Nozzle A, Safety Nozzle B, and the Spray Nozzle meet the acceptance standards Table IWB':'35 14-3 of Section XI of the ASME Boiler and Pressure Vessel Code (Reference
[4]). Additionally, this document will use a conservative methodology to show that the interface length between the WOL and the nozzle base metal (excluding indications) is sufficient to transfer load back to the base metal without exceeding the allowable primary shear stress limits of Section III of the ASME code (Reference
[5]). 2.0 ANALYTICAL METHODOLOGY 2.1 Indication Area Evaluation As noted in Section 1.0, laminar flaws shall meet the acceptance standards of Table IWB-3514-3.
Per Note 1 of Table IWB-3514-3 the area of a laminar flaw is defined in IWA-3360.
IWA-3360(b) states the following: "The area of a laminar flaw shall be 0.75 times the area of the square or rectangle that contains the detected area of those flaws that either overlap or are within a distance S of 1 in. (25 mm) of one another as shown in Fig. IWA-3360-1." A laminar flaw is considered acceptable if the area calculated in accordance with IWA-3360 is less than the area allowed by Table IWB-3514-3.
2.2 Overlay Length Evaluation Additionally, it will be verified that the length of the weld overlay excluding the indications is sufficient to transfer the load through shear back to the base metal conservatively considering a 100% through wall crack in the PWSCC susceptible material.
The methodology utilized is described below. The cross-sectional area (Aner) and section modulus (Zner) of the net section are calculated considering a 100% through wall crack in the PWSCC susceptible material as Page 6 A AREVA Document No. 32-9200291-000 DCPP Unit 2 -Evaluation of Laminar Indications on Pressurizer Nozzles (Non-Proprietary) ff( 2 2) Anet ="4 (D + 2t) -D z == 2x i net net (D + 2t)
_D4) 64 (D + 2t) where D is the OD of the nozzle base metal, and t is the minimum weld overlay thickness.
The extreme fiber tensile stress is calculated based on the net section properties with faulted moment (M) and axial load (F). (1) (2) (3) Conservatively consider the maximum allowable shear for the faulted case to be O.6S m (see NB-3227.2, Reference
[5]) although the faulted allowable is higher. A force balance on the WOL with the maximum shear stress at the interface gives Solving for the required minimum overlay length, lreq, gives 1 = (j'net X t req 0.6SI/7 The effective length of the weld overlay is 1 eff = 111'01 -I jlaw where 111'01 is the length of the weld overlay show on the design drawings for minimum thickness conditions and ljlaw is the axial dimension of the laminar flaw. The length of the weld overlay is acceptable provided that leffis greater than lreq. 2.2.1 Overlay Length Evaluation Conservatisms Conservatism present in the calculation methodology described in Section 2.2 is noted below: (4) (5) (6) I. This method conservatively treats the length of the overlay as being loaded in pure shear even though part of the stress at the nozzle taper is normal stress, which would have a significantly higher limit and reduce the load carried in shear. 2. The allowable primary shear stress for faulted loads is 0.42S u (Reference
[5], Appendix F, F-1331.1(d)).
This document conservatively uses the faulted loads with the NB-3227.2 allowable of O.6S m* Page 7 A AREVA Document No. 32-9200291-000 DCPP Unit 2 -Evaluation of Laminar Indications on Pressurizer Nozzles (Non-Proprietary)
- 3. The methodology considers the laminar indications extending 360 0 around the cir c umference while the actual indications have a lesser extent. Additionally, the methodology is assuming that the maximum net section stress (Equation
- 3) is occurring around the full circumference. 4. The maximum axial dimension of the flaw is conservatively used. The actual axial dimension varies along the arc length of the indication.
3.0 ASSUMPTIONS No assumptions or modeling simplifications were used in this calculation.
4.0 CALCULATIONS 4.1 PZR Safety Nozzle A Dimensions of laminar indications 1 and lA on PZR Safety Nozzle A are provided in the figure "WIB-368 Overlay Rollout" of Reference
[1] which is shown below. SA-508 Safety . NozzJe" N' 11------13.5" --+-----;1 3.5" 16.3" (18.75")"
316 SS S af e-e nd Al l oy 521/1kld Overlay lS I Ex am Vo l u r'l'l:! Cooe Cov era ge Box " 18.75" i s measured on OD su rf ace Circumference origi n a l p i pe base mate r ia l;:: 2 5" Circumfer ence o f overlay = 28.75' (25128.75) *18.75 = 1 6.3" true i nd icat i o n le n gth \NIB-368 Ov e rlay Rollo u t " A" S a fety Nozzle 3 08 SS Weld VVl B-368 316 SS Pip i ng Figure 4-1: WIB-368 Overlay Rollout Safety Nozzle "A" (Reference
[1]) As shown in Figure 4-1 indications 1 and 1 A are separated by less than 1 inch so they are treated as one indication in accordance with IW A-3360(b).
The combined dimensions utilizing the true indication length are f A = 16.3 in and W A = 0.4 in. Therefore, in accordance with IW A -33 60(b) the area of the laminar flaw is calculated as Page 8 A AREVA Document No. 32-9200291
-000 DCPP Unit 2 -Evaluation of Laminar Indications on Pressurizer Nozzles (Non-Proprietary)
A A = 0.7 5 (w A x f A) = 0.7 5(0.4 in x 16.3 in) = 4.89 in 2 The area, AA, determined above shall not exceed the limits specified in Table IWB-3514-3.
The most restrictive limit in Table IWB-3514-3 of Reference
[4] applies for any wall thickness less than 3.5 inches and sets the maximum allowable laminar flaw area to be 7.5 in 2* Since the calculated area of 4.89 in 2 is less than the allowed area (7.5 in 2), the requirements of Table IWB-3514-3 are met for the laminar indications on Nozzle A. 4.2 -PZR Safety Nozzle B The Indication Data Sheet "Safety Nozzle B WIB-423 OL" (Reference
[1]) shows that in the case of Nozzle B the distances between any two adjacent indications is less than 1 inch; therefore, in accordance with the three indications are combined.
Dimensions of the indications are provided in the figure "WIB-423 Overlay Rollout" of Reference
[1] which is shown below. SA-508 Safety Nozz l e "8" Pressurize r 5.5" "A" Datum Alloy 821182 Buttering 316 SS Safe-end Alloy 52 Weld Overlay lSI Exam Volume Code Coverage Box -------_.--1----_._---
_. __ ._---/ I I I I 316 SS Pip i ng Figure 4-2: WIB-423 Overlay Rollout Safety Nozzle "B" (Reference
[1]) From Figure 4-2 above the corrected length from the start of indication 1 to the end of indication 3 is lB = 4.7 in, and the axial length of the indications is WB = 0.25 in. Therefore, in accordance with IWA-3360(b) the area of the laminar flaw is calculated as Page 9 A AREVA Document No, 32-9200291
-000 DCPP Unit 2 -Evaluation of Laminar Indications on Pressurizer Nozzles (Non-Proprietary)
The area, A B , determined above shall not exceed the limits specified in Table IWB-3514-3. The most restrictive limit in Table IWB-3514-3 of Reference
[4] applies for any wall thickness less than 3,5 inches and sets the maximum allowable laminar flaw area to be 7.5 in 2* Since the calculated area of 0,88 in 2 is less than the allowed area (7.5 in 2), the requirements of Table IWB-3514-3 are met for the laminar indications on Nozzle B. 4.3 PZR Spray Nozzle The indications detected on the PZR Spray Nozzle are shown on Figure 4-3 and with additional information provided in the Indication Data Sheet "WIB-345 OL Spray Nozzle" (Reference
[1]). Pressurize r Note: All indication lengths are uncorrected, SA-508 Spray Nozzle k-1,7" 0,88" 0,5" 0 , 8' 4.!c-Alloy 52 Weld Overlay Indications 2 & 3 Indication
- 1 0.42" Ind , 1 & 4 0,8"
- 1"* 0 , 75" 308 SS Wald VV1B-345 316 SS Piping O , 25"typ , Figure 4-3: WIB-345 Overlay Rollout Spray Nozzle (Reference
[1]) Alloy 821182 Buttering , Per the Indication Data Sheet "WIB-345 OL Spray Nozzle" (Reference
[1]), indication 4 intermittently starts and stops around the entire 360 0 circumference; although some sections are separated by more than 1 inch, for conservatism, the entire length from the indication start (0.5") to the indication stop (20.6") will be considered as one laminar flaw of length I = 20.6"-0.5" = 20.1". As seen in Figure 4-3, the maximum width where indications 1 and 4 overlap is w = 0.42". Therefore, in accordance with IW A-3360(b) the area of the laminar flaw is calculated as Page 10 A AREVA Document No. 32-9200291-000
- DCPP Unit 2 -Evaluation of Laminar Indications on Pressurizer Nozzles (Non-Proprietary)
A = 0.75{w x t) = 0.75{0.42 in x 20.1 in) = 6.33 in 2 The area, A, determined above shall not exceed the limits specified in Table IWB-3S14-3.
The most restrictive limit in Table IWB-3S14-3 of Reference
[4] applies for any wall thickness less than 3.S inches and sets the maximum allowable laminar flaw area to be 7.S in 2* Since the calculated area of6.33 in 2 is less than the allowed area (7.S in 2), the requirements of Table IWB-3S14-3 are met for the laminar indications on the PZR Spray Nozzle. 4.4 Overlay Length Calculations Following the methodology described in Section 2.2 the required length for the safety nozzles is calculated and reported in Table 4-1. Table 4-1: Required WOL Length for Safety Nozzles Parameter Value Reference/Comments t (in) [ ] Reference
[6] D (in) [ ] Reference
[6] Znet (in 3) 19.53 Equation (2) Anet (in 2) 9.73 Equation (1) M(in-Ibi)
[ ] Faulted, Reference
[7] MIZ net (psi) [ ] F (lbi) [ ] Faulted, Reference
[7] FIA net (psi) [ ] MIZ net + FIA net (ksi) [ ] Equation (3) Sm (ksi) 23.3 Per Reference
[7] material is SB-166 N06690 with a bounding temperature of 700°F; properties from Reference
[8] lreq (in) 0.769 Equation (S) Page 11 A AREVA Document No. 32-9200291-000 DCPP Unit 2 -Evaluation of Laminar Indications on Pressurizer Nozzles (Non-Proprietary)
Following the methodology described in Section 2.2 the required length for the spray nozzle is calculated and reported in Table 4-2. Table 4-2: Required WOL Length for Spray Nozzle Parameter Value Reference/Comments t (in) [ ] Reference
[9] D (in) [ ] Reference
[9] Znet (in 3) 8.95 Equation (2) Anet (in 2) 5.94 Equation (1) M (in-Ibf) [ ] Faulted, Reference
[10] MIZ net (psi) [ ] F (lbf) [ ] Faulted, Reference
[10] FIA net (psi) [ ] MIZ net + FIA n e t (ksi) [ ] Equation (3) Sm (ksi) 23.3 Per Reference
[10] material is SB-166 N06690 with a bounding temperature of 700°F; properties from Reference
[8] lr eq (in) 0.476 Equation (5) The design lengths of the WOLs are shown for the Safety Nozzles and the Spray Nozzle in Figure 4-4 and Figure 4-5, respectively.
Figure 4-4: Safety Nozzle Weld Overlay Length (Reference
[6]) Page 12 A AREVA Document No. 32-9200291-000 DCPP Unit 2 -Evaluation of Laminar Indications on Pressurizer Nozzles (Non-Proprietary)
Figure 4-5: Spray Nozzle Weld Overlay Length (Reference
[9]) The effective length is calculated and compared against the required length in Table 4-3. Table 4-3: WOL Length Verification Safety Nozzle A Safety Nozzle B Spray Nozzle Comments Drawing Reference
[6] Reference
[6] Reference
[9] lwo! (in) 1.31 1.31 1.68 Figure 4-4 and Figure 4-5 &taw (in) 0.4 0.25 0.42 Sections 4.1, 4.2, and 4.3 lejj(in) 0.91 1.06 1.26 Equation (6) lreq (in) 0.769 0.769 0.476 Table 4-1 and Table 4-2 Check l ejj> lr eq OK OK OK As seen above in Table 4-3, using the conservative methodology of Section 2.2 the WOL on each nozzle has sufficient margin over the required length to transfer loads back to the base metal. Page 13 A AREVA Document No. 32-9200291-000 DCPP Unit 2 -Evaluation of Laminar Indications on Pressurizer Nozzles (Non-Proprietary)
5.0 CONCLUSION
S The laminar indications detected during inservice inspection ofPZR Safety Nozzle A, Safety Nozzle B, and the Spray Nozzle at DCPP Unit 2 meet the acceptance standards of Table IWB-3514-3 of Section XI of the ASME Code (Reference
[4]). The WOL on each nozzle has been verified to have sufficient length to transfer loads back to the base metal without exceeding allowable primary shear stresses ofNB-3227.2 of Reference
[5].
6.0 REFERENCES
- 1. AREVA Document 38-9200149-000, "DCPP Unit 2 Pressurizer Nozzle NDE Data". 2. PG&E Letter DCL-07-099 dated October 22,2007, "ASME Section XI Inservice Inspection Program Relief Request REP-l U2, Revision 1, and Response to Request for Additional Information" (ADAMS No. ML073040029).
- 3. "Safety Evaluation by the Office of Nuclear Reactor Regulation
-Request for Relief from the American Society of Mechanical Engineers Boiler and Pressure Vessel Code,Section XI, Inservice Inspection Program, Pacific Gas and Electric Company, Diablo Canyon Power Plant, Unit No.2 Docket No. 50-323" Dated February 6,2008 (ADAMS No. ML080110001).
- 4. ASME Boiler and Pressure Vessel Code,Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components" 2004 Edition with Addenda Through 2005. 5. ASME Boiler and Pressure Vessel Code,Section III, 2004 Edition with Addenda Through 2005. 6. ARE VA Document 02-8019311D-001, "Diablo Canyon Pressurizer Safety and Relief Nozzle Weld Overlay Design Input". 7. AREVA Document 32-9043545-001, "Diablo Canyon Unit 2, Pressurizer Safety/ReliefNozzle Weld Overlay Sizing Calculation".
- 8. ASME Boiler and Pressure Vessel Code,Section II, Part D, "Properties" 2004 Edition with Addenda Through 2005. 9. AREVA Document 02-8019233D-001, "Diablo Canyon Pressurizer Spray Nozzle Weld Overlay Design Input". 10. AREVA Document 32-9043546-001, "Diablo Canyon Unit 2, Pressurizer Spray Nozzle Weld Overlay Sizing Calculation".
Page 14 Enclosures 3 and 4 contain Proprietary Information
-Withhold Under 10 CFR 2.390 Enclosure 8 PG&E Letter DCL-13-021 Commitment
- lSI examination of Safety Nozzle A, B, and C, and the Spray Nozzle SWOLs will be performed during the next three lSI periods in accordance with Section XI, IWB-2420.
Enclosures 3 and 4 contain Proprietary Information When separated from Enclosures 3 and 4 , this document is decontrolled.