ML13305A122
| ML13305A122 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 11/25/2013 |
| From: | Noronha S AREVA |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| 32-9212003-000 | |
| Download: ML13305A122 (21) | |
Text
License Amendment Request No. 2012-10, Supplement 2 October 25, 2013 ENCLOSURE 3 AREVA Document No. 32-9212003-000 "LST considering RCS Piping and RVCH Limit for B&W Plant Designs" September 2012 Non-Proprietary Version
Controlaed Document 0402-01-FOI (Rev. 017, 11/19/12)
A CALCULATION
SUMMARY
SHEET (CSS)
AREVA Document No. 32 - 9212003 - 000 Safety Related: Z Yes D No Title LST considering RCS Piping and RVCH Limit for B&W Plant Designs PURPOSE AND
SUMMARY
OF RESULTS:
AREVA NP Inc. proprietary Information In the document are removed and their locations are Indicated by pairs of brackets "[ 1". This document is the non-proprietary version of AREVA Document 32-9208072-001.
The P-T limits are required to be generated for all the ferritic pressure boundary components of the reactor coolant system (RCS) as prescribed in 10 CFR 50 Appendix G. For B&W nuclear steam supply systems, Topical Report BAW-10046A, Revision 2 [2] describes methods for compliance with the requirements of 10 CFR 50 Appendix G [1]. BAW-10046A, Rev 2 uses procedures of ASME Code Section III Appendix G [3] to calculate the pressure-temperature limits of the reactor vessel beltline region, reactor vessel closure head (RVCH) region and reactor vessel nozzle region; it uses lowest service temperature (LST) criterion to determine the P-T limits of RCS loop piping and the control rod drive mechanism (CRDM) motor tubes. The purpose of this document is to determine the limiting component in the ferritic pressure components of RCS that establishes the lowest service temperature.
BAW-1 0046 Rev 2 [2] prescribes [ ] IF as the LST for control rod drive mechanism (CRDM) motor tubes which includes an additional margin of [ I IF beyond the required values. Here we prescribe the LST of the CRDM as [ I IF by removing the additional margin. The [ I OF LST still satisfies the ASME Code and 10CFR Appendix G requirements.
BAW-10046 Rev 2 [2] used ASME Code [3] Section III NB-3211(d)(2) to establish an LST of ( I IF for RCS piping. In this document we followed the alternate provision prescribed in ASME Code Section III NB-321 1(d)(1). The evaluation performed in Section 7.2 shows that the allowable pressures for the RCS piping are significantly higher than the RVCH and are thus not limiting at any temperature. The evaluation in Section 7.2 demonstrates that the limiting component at low temperatures is the RVCH and removes the requirement to include the LST of RCS piping in the P-T limits.
0 The evaluation establishes LSTs for the B&W designed plants that are approximately [ OF greater than the minimum temperature requirements of 10CFR50, Appendix G. Based on the results of this evaluation, it is determined that for the B&W designed plants the LST is established by the RVCH. In other words, the RVCH continues to remain as the limiting LST component in the RCS as concluded in BAW-1 0046 Rev. 2 [2].
THE DOCUMENT CONTAINS ASSUMPTIONS THAT SHALL BE THE FOLLOWING COMPUTER CODES HAVE BEEN USED IN THIS DOCUMENT: VERIFIED PRIOR TO USE CODENERSION/REV CODENERSION/REV E'- YE PTPC 4.2ZN S42Z YES Page 1 of 20
Doctrient
/ ., 0402-01-FOl (Rev. 017, 11/19/12)
Document No. 32-9212003-000 LST considering RCS Piping and RVCH I-imit for B&W Plant Designs Reciew Method: v] Design Review (Detailed Check)
L-] Alterl ale Calculation Signature Block P/RIA Name and Title and Pages/Sections (printed or typed) Signature LP/LR Date PreparedlReviewed/Approved Silvester J Noronha p,.icipal Engineer l'"1,1 ALL Douglas E Killian Technical Consultant R ALL Timothy M. Wigeri Un it Manager- A V?71zALL, Note: P/R/A designates Preparer (P), Reviewer (R), Approver (A);
LP/LR designates Lead Preparer (LU), Lead Reviewer (LR)
Project Manager Approval of Customer References (N/A if not applicable)
Name Title (printed or typed) (printed or typed) Signature Date N/A N/A N/A N/A Mentoring Information (not required per 0402-01)
Name Title Mentor to:
(printed or typed) (printed or typed) (P/R) Signature Date Page 2
Controfled Docurnent A
AR EVA 0402-01 -F01 (Rev. 017, 11/19/12)
Document No. 32-9212003-000 LST considering RCS Piping and RVCH Limit for B&W Plant Designs Record of Revision Revision Pages/Sections/Paragraphs No. Changed Brief Description I Change Authorization 000 ALL Original Release i i I. 4 i i I. 4 Page 3
A AREVA Document No. 32-9212003-000 LST considering RCS Piping and RVCH Limit for B&W Plant Designs Table of Contents Page SIG NATURE BLOCK ............................................................................................................................. 2 RECORD O F REVISIO N ....................................................................................................................... 3 LIST O F TABLES .................................................................................................................................. 6 LIST O F FIG URES ................................................................................................................................ 6 1.0 INTRO DUCTIO N ........................................................................................................................ 7 2.0 BACKG RO UND .......................................................................................................................... 7 3.0 M ETHOD O F ANALYSIS .................................................................................................... 9 3.1 Assessment of CRDM LST ........................................................................................................ 9 3.2 Appendix G Evaluation Methodology for RCS Piping .................................................................. 9 3.3 LST Evaluation of RVCH ........................................................................................................... 10 4.0 ASSUM PTIO NS ....................................................................................................................... 10 4.1 Unverified Assumptions .............................................................................................................. 10 4.2 Engineering Judgment ................................................................................................................... 10 4.3 Modeling Simplifications ........................................................................................................... 11 5.0 DESIGN INPUTS FOR APPENDIX G EVALUATION OF RCS PIPING ................................ 11 5.1 G e o m e try Da ta ............................................................................................................................... 11 5.2 Hot Leg Piping Materials ........................................................................................................... 11 5.3 Heatup and Cooldown Transient Definitions ............................................................................ 12 5.4 Convection Film Coefficient ....................................................................................................... 12 5.5 Closure Head Limits ....................................................................................................................... 13 6.0 CO M PUTER USAGE ............................................................................................................... 14 6.1 Software and Hardware .............................................................................................................. 14 6 .2 C o m p ute r F ile s ............................................................................................................................... 14 7.0 RESULTS ................................................................................................................................. 15 7.1 LST Evaluation of CRDM Nozzle ............................................................................................... 15 7.2 Appendix G Evaluation of RCS Piping ..................................................................................... 15 Page 4
Controfled Document A
AREVA Document No. 32-9212003-000 LST considering RCS Piping and RVCH Limit for B&W Plant Designs Table of Contents (continued)
Page 7.3 Evaluation of LST for RV CH ...................................................................................................... 18 8 .0 CO NC LUS IO N ......................................................................................................................... 19 9 .0 R E F E R E N C E S ......................................................................................................................... 20 Page 5
Controfled Document A
AR EVA Document No. 32-9212003-000 LST considering RCS Piping and RVCH Limit for B&W Plant Designs List of Tables Page Table 5-1: G eom etry Data for HL Piping .......................................................................................... 11 Ta ble 5-2 : HL Mate ria ls ....................................................................................................................... 11 T able 5-3: Material Properties ........................................................................................................ . . 12 T a ble 6-1: C om p ute r F ile s .................................................................................................................. 14 Table 7-1: HL P-T Limit Data for Normal Ramp Heatup at [ ) °F/hr ........................................... 16 Table 7-2: HL P-T Limit Data for Normal Ramp Cooldown at [ ] OF/hr ....................................... 17 List of Figures Page Figure 5-1: RVCH Uncorrected P-T Limits for B&W designed plants ............................................. 13 Figure 7-1: Comparison of RVCH and HL Uncorrected P-T Limits for B&W designed plants ...... 18 Page 6
ConrolUed Document A
AR EVA Document No. 32-9212003-000 LST considering RCS Piping and RVCH Limit for B&W Plant Designs
1.0 INTRODUCTION
Code of Federal Regulations Title 10, Part 50 (10 CFR 50) Appendix G [1] dictates that for all ferritic material pressure boundary components of the reactor coolant system (RCS), pressure-temperature (P-T) limit curves should be developed per ASME Code Section IHl/XI Appendix G [3, 4]. 10CFR 50, Appendix G prescribes additional pressure and temperature requirements, including minimum temperature requirements for the reactor pressure vessel that are summarized in Table 1 of [1]. These minimum temperature requirements [1] will also be discussed in addressing and establishing the limiting component that defines the lowest service temperature (LST) in the development of the P-T limit curves. For Babcock & Wilcox (B&W) nuclear steam supply systems, topical report BAW-10046A, Revision 2 [2] describes methods for compliance with the requirements of 10 CFR 50 Appendix G [1].
BAW-10046A Rev 2 [2] uses the procedures of ASME Code [3, 4] Appendix G to calculate the P-T limits of reactor vessel beltline region, reactor vessel closure head (RVCH) region and reactor vessel nozzle region which are identified as the controlling regions that regulate the pressure-temperature limitations of the reactor coolant system (RCS) for normal operation and in-service pressure tests. The RCS loop piping and the control rod drive mechanism (CRDM) motor tubes are addressed using the LST criterion. The RVCH was evaluated considering a relatively high RTNDT value of [ ] 0F and the LST for the closure head flange (per Figures 5-8 through 5-11 of Ref. [2]) was determined to be greater than 2000 F. As a result, the LST corresponding to the closure head flange was demonstrated to bound the LST of the RCS piping and the CRDM [2]. The purpose of this document is to reevaluate the minimum temperature requirements of RVCH, RCS piping and the CRDM.
2.0 BACKGROUND
The pressure-temperature (P-T) limits and minimum service temperature requirements of pressure retaining components of reactor coolant systems (RCS) that are made of ferritic materials are prescribed by Code of Federal Regulations Title 10, Part 50 (10 CFR 50) Appendix G [1]. For pressures above 20% of the pre-service system hydrostatic test pressure, the requirement of Item 2.b in Table 1 of Appendix G to 10 CFR Part 50 [1] states that the temperature must be at least 120 OF above the reference temperature of the closure head flange material. The 10 CFR 50 Appendix G also requires that the requirements of ASME Boiler and Pressure Vessel Code (ASME Code) be met in addition to the requirements set forth in 10CFR 50. ASME Code Section III [3] Article NB-3211 defines Page 7
Contr.csl Documen A
AREVA Document No. 32-9212003-000 LST considering RCS Piping and RVCH Limit for B&W Plant Designs Lowest Service Temperature (LST) as "the minimum temperature of the fluid retained by the component or, alternatively, the calculated volumetric average metal temperature expected during normal operation, whenever pressure within the component exceeds 20% of the pre-operational system hydrostatic test pressure". As per ASME Code Section Ill [3], Article NB-3211 (d) "Protection against nonductile fracture shall be provided by satisfying one of the following provisions:
(1) performing an evaluation of service and test conditions by methods similar to those contained in Appendix G; or (2) for piping, pump, and valve material thickness greater than 2% in. (64 mm) establishing a lowest service temperature(LST) that is not lower than RTNDT (NB-2331) + 100°F (56°C);
(3) for piping, pump, and valve material thickness equal to or less than 2/ in. (64 mm), the requirements of NB-2332(a) shall be met at or below the lowest service temperature as established in the design specification."
Topical Report BAW-10046A, Revision 2 [2] describes methods for compliance with the requirements of 10 CFR 50 Appendix G [1] for the B&W plants. The safety evaluation report (SER) for BAW-10046A, Revision 2 [2], states "BAW 10046, Rev. 2 describes acceptable methods for the development of allowable pressure-temperature limits for normal operation and for test conditions to assure the prevention of non-ductile fracture. It may be referenced in future applications..."
The methodology used for B&W plants includes all the ferritic components in the Reactor Coolant System (RCS). Acceptable methods for the determination of P-T limits for the closure head, the reactor vessel outlet nozzle, and beltline region are documented. As stated in BAW-1 0046A, Revision 2 "These three regions are the only ones that, at different stages of the vessel's design life, regulate the pressure-temperature limitations of the RC system for normal operation and inservice pressure tests."
The P-T limits determined for these components are determined and the resulting composite limiting curve is then determined utilizing the standard B&W methodology.
Per BAW-10046, Revision 2, "The components for which the lowest service temperature must be defined include the RC loop piping and the control rod drive mechanism." "The lowest service temperature of these components is [ ] OF (based on RTNDT + 100 OF) for the piping and [ ] OF for the CRDM." Thus BAW-10046A Revision 2 used ASME Code Section III NB-3211 (d) (2) to satisfy the conditions for protection against non-ductile failure.
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Contrdlld Docurnen A
AREVA Document No. 32-9212003-000 LST considering RCS Piping and RVCH Limit for B&W Plant Designs Since BAW-10046A Rev 2 (2] was approved:
(a) the ASME Section XI Appendix G fracture toughness reference curve KIR [4] has been changed from K18 (critical stress intensity factor for crack arrest) to KI, (critical stress intensity factor for static crack initiation), and (b) the Reactor Vessel Closure Heads (RVCHs) have been replaced in all the B&W designed plants.
The new/replacement RVCHs have much lower RTNDT value than ] 0OF reported in BAW-10046 Rev 2 [2]. The RTNDT of current RVCH materials for ANO-1, DB-1 and TMI-1 is ] 0 OF [5,6,7] and that for ONS Units 1, 2 and 3 is [ ] 0 F[8].
3.0 METHOD OF ANALYSIS In this report, we reevaluate the LST requirements for:
(1) CRDM by assessing the evaluation in Reference [2]
(2) RCS piping, following the provisions of ASME Code Section III NB-3211 (d)(1), and (3) RVCH using the current RTNDT of replacement RVCH.
3.1 Assessment of CRDM LST In BAW-10046 Rev 2 [2] it is determined that the required LST based on 10CFR 50 Appendix G for CRDM nozzles is [ 1 0F. However, BAW-1 0046 Rev 2 [2] suggests using a LST of 1 0OF for pressures above [ ] psig (20% of [ ] psig). In Section 7.1, we reassess this LST value.
3.2 Appendix G Evaluation Methodology for RCS Piping A detailed Appendix G evaluation as permitted per ASME Code Section III NB-3211 (d)(1) will be used in this evaluation in lieu of the provisions of NB-3211 (d)(2) as used in BAW-10046, Rev 2 for the determination of the LST of the RCS piping. The P-T limits for RCS piping are developed in accordance with the requirements of the ASME Boiler and Pressure Vessel Code,Section III and XI, Appendix G [3, 4] which permits the use of the K1, fracture toughness curve. Hot Leg (HL) piping is analyzed here as the most limiting section of the RCS piping. Allowable pressures are calculated as a function of reactor coolant inlet temperature based on the approved linear elastic fracture mechanics Page 9
Controled Document A
AREVA Document No. 32-9212003-000 LST considering RCS Piping and RVCH Limit for B&W Plant Designs methodology in topical report BAW-10046A [2], using a safety factor of 2 on pressure for the normal heatup and cooldown (HUCD) transients considered herein. The computer code PTPC [9] is used to calculate uncorrected allowable pressures for the beftline and nozzle regions of the reactor vessel according to:
KIR -KIT SF x where P6,,,, allowable pressure KIR reference stress intensity factor = Kic KIT thermal stress intensity factor R = unit pressure stress intensity factor (due to 1 psig)
SF = safety factor For each analyzed transient, the uncorrected allowable pressure is determined as a function of fluid temperature at 1/4t inside and outside surface flaw locations in the HL.
3.3 LST Evaluation of RVCH The RTNDT value of RVCH reported in BAW-10046 Rev 2 [2] is [ ] OF. Thus, based on 10CFR50 Appendix G the minimum temperature at which the service pressure can be just above 20% of the pre-service hydrostatic test pressure ( [ ] psi) was [ ] OF. The replacement RVCHs in B&W Plants have RTNDT values lower than [ ] OF that was used as a generic value for the original B&W designed RVCH. In Section 7.3, the minimum temperature requirement as per 10CFR50 Appendix G is reevaluated based on the new RTNDT values.
4.0 ASSUMPTIONS 4.1 Unverified Assumptions There are no unverified assumptions.
4.2 Engineering Judgment HL piping is judged to bound the RCS piping for the analysis.
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Contrnohd Documentn A
AREVA Document No. 32-9212003-000 LST considering RCS Piping and RVCH Limit for B&W Plant Designs 4.3 Modeling Simplifications There are no modeling simplification assumptions other than those used in the PTPC program [9].
6.0 DESIGN INPUTS FOR APPENDIX G EVALUATION OF RCS PIPING The design input information that will be used in performing the P-T limits analysis is addressed in this section.
5.1 Geometry Data Table 5-1: Geometry Data for HL Piping
- a. Reactor Coolant Piping Geometry HL outer radius, Ro HL inner radius, RF Cladding thickness
- b. Hot Leg Flaw Per Article G-2120 of ASME Code Section Xl [4], a longitudinal semi-elliptical surface flaw 1/4t (where t= wall thickness) deep and 3/2t long is postulated at both the inside and outside surfaces of the HL piping.
6.2 Hot Leg Piping Materials The HL Piping Materials which are relevant to the development of P-T limits are listed below.
Table 5-2: HL Materials Vessel Component Type of Original Material Material Designation Hot Leg Piping L The properties that are used for these materials in the present P-T limits analysis are listed in Table 5-3. These properties were obtained from the ASME Code [11] and Reference [12] for the HL material (and thermal conductivity for cladding material used to compute an effective base metal film coefficient). A typical Poisson's ratio of 0.3 is used.
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Con'trofld Document A
AREVA Document No. 32-9212003-000 LST considering RCS Piping and RVCH Limit for B&W Plant Designs Table 5-3: Material Properties Temp. Elastic Thermal(2) Thermal Specific Density Thermal Modulus Expansion Conductivity Heat Conductivity for Cladding Material
[11] [11] [12] [12] [12] [12]
(OF) (106 psi) (10" in/inf F) (Btu-in/hr-ft2-OF) (Btu/lb-0 F) (lb/ft3) (Btu-in/hr-ft 2-°F) 70 29.2 6.4 376.3 0.104 490.9 103.9 100 29.06(1) 6.5 372.8 0.107 490.5 105.6 150 28.83(1) 6.6 367 0.111 489.9 108.4 200 28.6 6.7 361.1 0.115 489.2 111.3 250 28.35(1) 6.8 355.3 0.118 488.6 114.2 300 28.1 6.9 349.4 0.120 487.9 117.0 350 27.90(1) 7.0 343.6 0.123 487.3 119.9 400 27.7 7.1 337.7 0.125 486.7 122.7 450 27.4(1) 7.2 331.8 0.126 486.0 125.6 500 27.1 7.3 326 0.128 485.4 128.5 550 26.75(1) 7.3 320.1 0.130 484.7 131.3 600 26.40 7.4 314.3 0.133 484.1 134.2 650 25.85(') 7.5 308.4 0.135 483.4 137.0 700 25.30 7.6 302.6 0.139 482.8 139.9 Note: 1') The values are obtained by interpolating the available values; I Mean coefficients of thermal expansion are used.
The RTNDT value for the piping material [ ] is [ ] IF [2]. A value of 200 ksi/in [13] is used for the upper shelf fracture toughness for the HL piping material.
6.3 Heatup and Cooldown Transient Definitions The transients are analyzed for a linear ramp rate of [ ] 0F/hr for normal heatup and normal
- cooldown, 6.4 Convection Film Coefficient A value of [ ] BTU/hr-ft 2-OF [13] is used for an effective convection heat transfer film coefficient at the cladding-to-base metal interface for all the times during heatup and cooldown. The outside surface is always modeled as a perfectly insulated boundary.
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A AREVA Document No. 32-9212003-000 LST considering RCS Piping and RVCH Limit for B&W Plant Designs 6.5 Closure Head Limits Pressure-temperature limits for the reactor vessel head-to-flange closure region have been evaluated in References [5, 6, 7] and [8] based on the results from the detailed finite element stress analysis of the RVCH flange region and the use of the Kic curve for fracture toughness, as permitted by ASME Code Section III and XI [3, 4]. These closure head limits are shown below in Figure 5-1.
Figure 5-1: RVCH Uncorrected P-T Limits for B&W designed plants Page 13
Conirdoltej Doc~u nnen A
AR EVA Document No. 32-9212003-000 LST considering RCS Piping and RVCH Limit for B&W Plant Designs 6.0 COMPUTER USAGE 6.1 Software and Hardware Test cases test6c h.inp and test6cc.inp - influence coefficient solution for Kit from Reference [9] are run to verify that the answers are correct. The file test6ch.out contains output from the test case test6c-h.inp, and the file test6cc.out contains output from the test case test6c.c.inp. Review of the output files shows that the answers are identical to those contained in Reference [9].
- 1. Computer program tested: PTPC 4.2
- 2. Computer hardware used: Intel Core i7 CPU 2640 M @ 2.80 GHz, 8.0GB RAM, Windows 7 Enterprise 64-bit OS (Tag# 5VKW5S1)
- 3. Name of person running test: Silvester J Noronha
- 4. Date of test: 05-15-2012
- 5. Results and acceptability: The results in Test6ch.out and Test6cc.out listed in Table 6-1 agree exactly with the values in the verification report [9].
6.2 Computer Files All computer files, including the computer input/output files for the analysis in this document, and the computer program test cases are listed in this section. All files are available in AREVA NP Inc. ColdStor storage \cold\General-Access\32\32-9000000\32-9208072-000\official.
Table 6-1: Computer Files Page 14
Controlled Document A
AREVA Document No. 32-9212003-000 LST considering RCS Piping and RVCH Limit for B&W Plant Designs 7.0 RESULTS 7.1 LST Evaluation of CRDM Nozzle BAW-10046 Rev 2 [2] prescribes [ ] OF as the LST for the control rod drive mechanism (CRDM) motor tube. However it is noted that (Sec 3.3.2, Reference [2]) based on the test data of [
] steels the LST for CRDM materials is only [ ] OF and an additional margin of [ ' IF was included beyond the Code required values. In Reference [2] it is stated that "This specified lowest service temperature is [ ] OF above the temperature at which the fracture toughness requirements are specified and met. The additional [ ] OF provides margins of safety beyond that required by the ASME Code and by Appendix G to 10 CFR 50." In this analysis we propose to reduce the LST of the CRDM motor tube to [ ] OF by removing the additional margin used in BAW-10046 Rev 2 [2]. The
[ ] 0F LST still satisfies the ASME Code and 10CFR Appendix G requirements.
7.2 Appendix G Evaluation of RCS Piping The inputs provided in Section 5.0 are used to calculate the uncorrected P-T limits for the HL piping following the methodology discussed in Section 3.2. For both heatup and cooldown transients a conservative rate of [ ] °F/hr is used.
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A AREVA Document No. 32-9212003-000 LST considering RCS Piping and RVCH Limit for B&W Plant Designs Table 7-1: HL P-T Limit Data for Normal Ramp Heatup at [ 100 ] OF/hr Page 16
Conrria~d Docu~ment A
AREVA Document No. 32-9212003-000 LST considering RCS Piping and RVCH Limit for B&W Plant Designs Table 7-2: HL P-T Limit Data for Normal Ramp Cooldown at [ 100 ] °F/hr From Table 7-1 it can be seen that the allowable pressure values during heat up are quite high even at low temperatures. For temperatures [ ] OF and above the minimum allowable pressure is greater than 2400 psi. Also during cool down as seen in Table 7-2, the allowable pressure values are greater Page 17
A AREVA Document No. 32-9212003-000 LST considering RCS Piping and RVCH Limit for B&W Plant Designs than 2400 psi for temperatures above [ ] OF. On comparing the allowable (minimum) pressure values from Table 7-1 and Table 7-2 with the RVCH as shown in Figure 7-1, it can be seen that the allowable pressures for HL are much higher than the RVCH and that allowable pressure values of RVCH are controlling.
Figure 7-1: Comparison of RVCH and HL Uncorrected P-T Limits for B&W designed plants 7.3 Evaluation of LST for RVCH The RTNDT value of RVCH reported in BAW-10046 Rev 2 [2] is [ 0OF. Thus, based on 10CFR50 Appendix G the minimum temperature at which the service pressure can be above 20% of the pre-service hydrostatic test pressure ([ ] psi) was [ ] OF (RTNDT + 120 OF). With the replacement RVCH the RTNDT for ANO-1, DB-1 and TMI-1 is [ ] OF [5, 6, 7] and that for ONS Units is [ ] OF [8]. Thus per 10CFR50 Appendix G, the minimum temperature at which the pressure can Page 18
Controlled Document A
AREVA Document No. 32-9212003-000 LST considering RCS Piping and RVCH Limit for B&W Plant Designs be above [ I psig (20% of [ ] psig) reduces to [ ] OF for ANO-1, DB-1 and TMI-1 and
[ ] OF for ONS-1, 2 and 3. However, as can be seen in Figure 7-1, the LST for ANO-1, DB-1 and TMI-1 RVCH is [ ] OF and that for ONS-1, 2 and 3 is [ ] OF based on the results from the detailed finite element stress analysis and Appendix G [3, 4] evaluation of the RVCH. Thus, the LSTs for the RVCH are 10OF greater than the required minimum temperature of the RVCH per 10CFR50, Appendix G.
8.0 CONCLUSION
[ 0 OF as the LST for the control rod drive mechanism (CRDM)
BAW-10046 Rev 2 [2] prescribes motor tube. However it is noted that (Sec 3.3.2, Reference [2]) based on the test data of Type 403 modified steels the LST for CRDM materials is only [ ] OF and an additional margin of [ ] OF is included beyond the Code required value. In this analysis, we propose to reduce the LST of the CRDM motor tube to [ ] OF by removing the additional margin. The [ ] OF LST still satisfies the ASME Code and 10CFR Appendix G requirement.
[ 0 which is based on RTNDT +
The LST prescribed for RCS piping in BAW-1 0046 Rev 2 [2] is OF, 100OF for the RCS piping (RTNDT = [ ] OF for the piping [2]), a provision prescribed in ASME Code Section III NB-321 1(d)(2). In this document we followed the alternate provision prescribed in NB-3211(d)(1) which states that "Protection against non-ductile fracture shall be provided by satisfying one of the following provisions: (1) performing an evaluation of service and test conditions by methods similar to those contained in Appendix G". The evaluation performed in Section 7.2 shows that the allowable pressures for the RCS piping are significantly higher than the RVCH and are thus not limiting at any temperature. The evaluation in Section 7.2 demonstrates that the limiting component at low temperatures is the RVCH and removes the requirement to include the LST of RCS piping in the P-T limits.
The evaluation establishes LSTs for the B&W designed plants that are approximately 10°F greater than the minimum temperature requirements of 10CFR50, Appendix G. Based on the results of this evaluation, it is determined that for the B&W designed plants the LST is established by the RVCH. In other words, the RVCH continues to remain as the limiting LST component in the RCS as concluded in BAW-10046 Rev. 2 [2].
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Contirolled DOCUrie~nt A
AREVA Document No. 32-9212003-000 LST considering RCS Piping and RVCH Limit for B&W Plant Designs
9.0 REFERENCES
- 1. Code of Federal Regulations, Title 10, Part 50 - Domestic Licensing of Production and Utilization Facilities, Appendix G - "Fracture Toughness Requirements", [Federal Register Vol.
78, p. 34248, June 7, 2013]
- 2. AREVA Document BAW-10046A, Rev. 2, "Methods of Compliance with Fracture Toughness and Operational Requirements of 10CFR50, Appendix G," by H. W. Behnke et al., June 1986.
- 3. ASME Boiler & Pressure Vessel Code,Section III, July 2010
- 4. ASME Boiler & Pressure Vessel Code,Section XI, July 2010
- 5. AREVA Document 32-5041911-002, "ANO-1 Appendix G RV Closure Head Limit"
- 6. AREVA Document 32-9037975-002, "DB-1 Section Xl Replacement RV Closure Head (Chalon)
P-T Limits"
- 8. AREVA Document 32-9001959-001, "Oconee Units 1,2 & 3 Replacement RV Closure Head P-T Limits"
- 9. AREVA Document 32-1171775-010, "Verification of PTPC & User's Manuar'
- 10. AREVA Document 02-146628E-04, "Details for 36" ID Coolant Outlet Piping"
- 11. ASME Boiler and Pressure Vessel Code (B&PVC)Section II, July 2010
- 12. AREVA Document NPGD-TM-500, Rev. D, "NPGMAT - NPGD Material Properties Program User's Manual," March 1985
- 13. AREVA Document 51-1143704-00, "Procedure for Generating P-T Limits" Page 20