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NRR E-mail Capture - Presentation Slides for Duke Public Meeting
	ML15141A099
Person / Time
Site:	Catawba
Issue date:	05/20/2015
From:	Ed Miller; Plant Licensing Branch II
To:	Matthew Hardgrove; NRC/NRR/DSS
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	Download: ML15141A099 (26)
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NRR-PMDAPEm Resource From: Miller, Ed Sent: Wednesday, May 20, 2015 8:16 AM To: Hardgrove, Matthew; Diamond, David J (diamond@bnl.gov) (diamond@bnl.gov); Jenkins, Joel

Subject:

Presentation Slides for Duke Public Meeting Attachments: Duke Final slides for NRC RAPTOR presentation dated 5-19-15 rev 1.pptx; Catawba Unit 1 MUR RAI Whitepaper Slides_prop3_NRC.pptx Here are the slides used at the meeting yesterday.

Ed 1

Hearing Identifier: NRR_PMDA Email Number: 2099 Mail Envelope Properties (9C2386A0C0BC584684916F7A0482B6CA018F6CB564D4)

Subject:

Presentation Slides for Duke Public Meeting Sent Date: 5/20/2015 8:15:32 AM Received Date: 5/20/2015 8:15:00 AM From: Miller, Ed Created By: Ed.Miller@nrc.gov Recipients:

"Hardgrove, Matthew" <Matthew.Hardgrove@nrc.gov>

Tracking Status: None "Diamond, David J (diamond@bnl.gov) (diamond@bnl.gov)" <diamond@bnl.gov>

Tracking Status: None "Jenkins, Joel" <Joel.Jenkins@nrc.gov>

Tracking Status: None Post Office: HQCLSTR02.nrc.gov Files Size Date & Time MESSAGE 65 5/20/2015 8:15:00 AM Duke Final slides for NRC RAPTOR presentation dated 5-19-15 rev 1.pptx 151263 Catawba Unit 1 MUR RAI Whitepaper Slides_prop3_NRC.pptx 572923 Options Priority: Standard Return Notification: No Reply Requested: No Sensitivity: Normal Expiration Date:

Recipients Received:

Justification for the use of RAPTOR-M3G for the Catawba Unit 1 Measurement Uncertainty Recapture Power Uprate (MUR)

Fl Fluence EEvaluations l i Cecil Fletcher, Catawba Nuclear Station Manager off Regulatory l Affairs ff Mayy 19, 2015

Justification for the Use of RAPTOR-M3G for the Catawba Unit 1 Measurement Uncertainty Recapture Power Uprate Fluence Evaluations Purpose p of the meetingg

Duke requested this meeting to present its written response to RAI SRXB-RAI SRXB RAI 8.

The RAPTOR-M3G code used to calculate fluence for MUR conditions does not appear to be approved by the NRC for generic application.

This meeting coupled with additional technical information submitted to the NRC provides the justification for the use of RAPTOR-M3G for the Catawba Unit 1 MUR Power Uprate Fluence evaluations.

2

Justification for the Use of RAPTOR-M3G for the Catawba Unit 1 Measurement Uncertainty Recapture Power Uprate Fluence Evaluations Project Overview

During the course of the project, design and operational margin evaluations have been completed on all Catawba Unit 1 and Shared Structure, Systems and Components (SSCs).

These evaluations demonstrate that Catawba Unit 1 and Shared SSCs have sufficient margin g to accommodate the MUR Power Uprate.

Cameron Measurement Systems, Caldon Ultrasonics LEFM CheckPlus Flow Measurement system was installed in Catawba unit 1 in May 2014.

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Justification for the Use of RAPTOR-M3G for the Catawba Unit 1 Measurement Uncertainty Recapture Power Uprate Fluence Evaluations

LAR Submittal

Background:

Initial submittal made on June 23, 2014 consistent with Regulatory Issue Summary (RIS) 2002-03 format.

Supplemented on August 26 26, 2014 to confirm completion of commitment related to evaluation of components for acceptability for post-MUR equipment qualification (EQ) conditions.

First request q for additional information ((RAI)) response p letter submitted on December 15, 2014 (responded to questions from SRXB, SCVB, AFPB, EMCB, and ESGB branches and included WCAP-16083-NP and WCAP-17669-NP).

Second RAI response letter submitted on January 22, 2015 (responded to questions i ffrom EVIB and d EEEB branches).

b h )

Third RAI response letter submitted on April 23, 2015 (responded to questions from SRXB, ESGB, and EEEB branches and included WCAP-17993-NP).

4

Justification for the Use of RAPTOR-M3G for the Catawba Unit 1 Measurement Uncertainty Recapture Power Uprate Fluence Evaluations

2012 Decision to Use Raptor

- Both DORT/SYNTHESIS and RAPTOR-M3G RAPTOR M3G had been performed.performed Comparison showed:

The two methods calculated fluence values for the original beltline region that were in good agreement.

Being better able to track and account for high energy neutrons, RAPTOR fluence values in the extended beltline region were more realistic.

- RAPTOR was validated within Westinghouse using by past surveillance capsulel d dosimetry i t d data t per RReg. G Guide id 1.190.

1 190

- RAPTOR was previously used for South Texas Capsule fluence. NRC stated:

Should h ld ffuture evaluations l employl fl fluence methods h d that h h have not b been NRC reviewed and approved, adequate justification regarding the application and qualification of those methods should be provided. RG 1.190 provides guidance for acceptable fluence methods.

5

Justification for the Use of RAPTOR-M3G for the Catawba Unit 1 Measurement Uncertainty Recapture Power Uprate Fluence Evaluations

Catawba Reactor Vessel Material

- During recent license amendment submittals the NRC Staff has requested allll RV fferritic iti material t i lb be included i l d d when h addressing dd i ffracturet ttoughness h

requirement for RV integrity. RIS 2014-11 defines these requirements.

- As a result of considering all ferritic material for the MUR submittal, the lead material for P-T limits is located in the Catawba Unit 1 extended beltline region. Factors that contributed to the shift in location are:

The original beltline materials have good toughness properties based on actual material data.

Not all material p properties p are available for the extended beltline material resultingg in uncertainty which requires additional margin.

- The current Catawba Unit 1 P-T limits are for 34 EFPY. Using RAPTOR to calculate fluence including the extended beltline for MUR, the current P-T limits would be good for 30 30.7 7 EFPY EFPY. (Currently 25 25.1 1 EFPY)

- With inclusion of margin associated with extended beltline material/nozzles and possibly BTP 5-3, the improved accuracy obtained by using RAPTOR is important in maintaining adequate but reasonable operationall llimits.

6

Catawba Unit 1 MUR SRXB-RAI 8 Response Jianwei Chen Principal Engineer, Ph. D Greg A. Fischer Principal Engineer Engineer, P P.E.

E May 19, 2015 1

Background

The neutron fluence exposure at reactor pressure vessel (RPV) is an important input to the reactor vessel integrity (RVI) assessment, which is a critical evaluation for power uprate and plant life extension

Traditionally, the neutron fluence has been evaluated using discrete ordinates radiation transport codes:

- TWOTRAN (1968) - Can only solve 1-D 1 D and 2-D 2 D problems

- DOT (1970) - Can only solve 1-D and 2-D problems

- DORT (1980s) - Can only solve 1-D and 2-D problems

- TORT - Can solve 3-D problems problems, but not for full-size commercial reactor vessels per Regulatory Guide 1.190 pedigree due to computer resource limitations 2

Background

RAPTOR-M3G was developed to overcome TORTs limitations Feature TORT RAPTOR-M3G Solves the linear Boltzmann radiation transport equation in 3D Applies the method of discrete ordinates (the SN method) to treat directional variables Applies weighted finite-difference methods to treat spatial variables A li a multigroup Applies lti f formulation l ti tto treat t t energy dependence d d DOORS Package (DORT/TORT) input format Execute on a one-workstation platform Executes simultaneously in-parallel in parallel on a network of workstations Execute with theta-weighted (TW) spatial differencing scheme Execute with directional theta-weighted (DTW) spatial differencing scheme 3

Background

Westinghouse has performed the neutron fluence evaluation in support of the Catawba Unit 1 MUR using RAPTOR-M3G in WCAP-17669-NP, Revision 0

NRC issued SRXB-RAI 8:

- The RAPTOR-M3G code used to calculate fluence for MUR conditions does not appear to be approved by the NRC for use in this scenario. The NRC staff requests q that the licensee provide justification for the use of RAPTOR-M3G for fluence calculations for MUR conditions, or provide an alternative fluence calculation using an NRC approved method.

4

Westinghouse RAI Response

Westinghouse/Duke are providing justification to the NRC that the use of RAPTOR-M3G RAPTOR M3G for fluence calculations for MUR conditions is acceptable.

Additional Catawba Unit 1 specific p benchmark calculations have been done between TORT and RAPTOR-M3G

- For limiting RPV materials

- For representative fuel cycles

Due to computer limitations with TORT, three reduced size models were used:

- U Upper R Reactor t E Environment i t (URE) model d l (W (Weld ld 06)

- Midplane Reactor Environment (MRE) model (Weld 05)

- Lower Reactor Environment (LRE) model (Weld 04) 5

Westinghouse RAI Response Strategy Reduced Size Model + TW + TORT Demonstrate TORT and RAPTOR-M3G provide identical results Reduced Size Model + TW + RAPTOR-M3G Demonstrate Reduced Size Model has no impact Full Core Fine Mesh + TW + RAPTOR-M3G Demonstrate DTW is conservative for Weld W06 Full Core Fine Mesh + DTW + RAPTOR-M3G (NRC submittal) 4 sets of results for detailed comparison of TORT and RAPTOR-M3G runs 6

Results 7

Westinghouse RAI Response Calculations

RPV Materials Evaluated in Benchmark Calculations

- Upper Shell to Intermediate Shell Circumferential Weld W06

- Intermediate Shell to Lower Shell Circumferential Weld W05

- Lower Shell to Bottom Head Ring Circumferential Weld W04

Power Distributions used in Benchmark Calculations

- Cycle 3, representative of Out-In (High Leakage) core design strategies

- Cycle 21, representative of Low-Leakage core design strategies

- A time-weighted g average g of p power distributions through g 54 EFPY, to provide fluence projection at 54 EFPY based on one cycle calculation 8

Westinghouse RAI Response Calculations

URE model - 209 radial, 195 azimuthal, and 89 axial mesh intervals TORT and RAPTOR-M3G runs are using the same geometry model, materials, and source distributions 9

Westinghouse RAI Response Calculations

MRE model - 209 radial, 195 azimuthal, and 85 axial mesh intervals TORT and RAPTOR-M3G runs are using the same geometry model, materials, and source distributions 10

Westinghouse RAI Response Calculations

LRE model - 209 radial, 195 azimuthal, and 91 axial mesh intervals Combining all three reduced size models would be a full core model similar to geometry model used in WCAP-17669-NP, but still not as refined.

11

Westinghouse RAI Response Calculations

Boundary Conditions and Extent of Applicability for the Reduced Size Models Parameter Reduced-Size Model URE MRE LRE Bottom of Model* 0.0 cm -191.206 cm -363.296 cm Bottom Boundary Condition Reflective Void Void Top of Model* 343 46 cm 343.46 190 289 cm 190.289 0 0 cm 0.0 Top Boundary Condition Void Void Reflective Bottom Extent of Model Applicability* 75.0 cm -75.0 cm -330.0 cm Top Extent of Model Applicability* 300.0 cm 75.0 cm -75.0 cm Materials Analyzed in Model Weld W06 Weld W05 Weld W04

Dimensions are given relative to the active core midplane URE - Weld 06 MRE - Weld 05 12 LRE - Weld 04

Westinghouse RAI Response Calculation Results

Calculated Neutron Fluence Rates for Catawba Unit 1 Cycle 3 Model Calculated Neutron (E>1.0 MeV)

Fluence Rate ((Flux)) [n/cm2-s]

Weld W06 Weld W05 Weld W04 Reduced-Size Models (TORT) with TW 1.06E+09 2.36E+10 1.91E+09 Reduced-Size Models (RAPTOR-M3G) with TW 1 06E+09 1.06E+09 2 36E+10 2.36E+10 1 90E+09 1.90E+09 RAPTOR-M3G Model in WCAP-17669-NP, Rev. 0 1.06E+09 2.36E+10 1.90E+09 with TW RAPTOR-M3G RAPTOR M3G Model in WCAP WCAP-17669-NP 17669 NP, Rev Rev. 0 1 14E+09 1.14E+09 2 33E+10 2.33E+10 1 98E+09 1.98E+09 TORT and RAPTOR-M3G with TW methods give identical results (<1%).

(<1%)

RAPTOR-M3G with DTW method yields more conservative results for limiting weld W06 13

Westinghouse RAI Response Calculation Results

Calculated Neutron Fluence Rates for Catawba Unit 1 Cycle 21 Model Calculated Neutron (E>1.0 MeV)

Fluence Rate ((Flux)) [n/cm2-s]

Weld W06 Weld W05 Weld W04 Reduced-Size Models (TORT) with TW 6.41E+08 1.54E+10 1.20E+09 Reduced-Size Models (RAPTOR-M3G) with TW 6 40E+08 6.40E+08 1 54E+10 1.54E+10 1 20E+09 1.20E+09 RAPTOR-M3G Model in WCAP-17669-NP, Rev. 0 6.40E+08 1.54E+10 1.20E+09 with TW RAPTOR-M3G RAPTOR M3G Model in WCAP WCAP-17669-NP 17669 NP, Rev Rev. 0 6 98E+08 6.98E+08 1 54E+10 1.54E+10 1 26E+09 1.26E+09 TORT and RAPTOR-M3G with TW methods give identical results (<1%).

(<1%)

RAPTOR-M3G with DTW method yields more conservative results for limiting weld W06 14

Westinghouse RAI Response Calculation Results

Calculated Neutron Fluence after 54 EFPY at Catawba Unit 1 (Reduced-Size (Reduced Size Models calculated using time-weighted time weighted average power distributions)

Model Calculated Neutron (E>1.0 MeV)

Fluence [n/cm2]

Weld W06 Weld W05 Weld W04 Reduced-Size Models (TORT) with TW 1.05E+18 2.66E+19 1.83E+18 Reduced-Size Models (RAPTOR-M3G) with TW 1.05E+18 2.66E+19 1.83E+18 RAPTOR-M3G Model in WCAP-17669-NP, Rev. 0 1.05E+18 2.66E+19 1.83E+18 with TW (1.07E+18)* (2.63E+19)* (1.86E+18)*

RAPTOR-M3G Model in WCAP-17669-NP, Rev. 0 1.16E+18 2.60E+19 1.95E+18

The projected 54 EFPY fluence value in the parenthesis is calculated by accumulating cycle-specific fluence for cycles 1 through 22, and assuming Cycle 22 at MUR power for cycles beyond Cycle 22, the same approach used in WCAP-17669-NP, Rev. 0 TORT and RAPTOR-M3G with TW methods give identical results (<1%).

RAPTOR-M3G with DTW method yields more 15 conservative results for limiting weld W06

Westinghouse RAI Response Calculation Conclusions

TORT and RAPTOR-M3G produce nearly identical results, ii.e.,

e within 1% 1%, when using the same geometrical model and calculation control parameters

The results from RAPTOR-M3G and TORT agree better than the 13% uncertainty assigned to the calculational methodology and well within the 20% uncertainty deemed acceptable for RTPTS and RTNDT determination

The fast f neutron fluence f reported to NRC C ffor the limiting fluence at 54 EFPY (upper shell to intermediate shell circumferential weld W06) in WCAP-17669-NP, Rev. 0 is the bounding value

Therefore, the fast neutron flux / fluence values submitted to NRC in WCAP-17669-NP,, Rev. 0 are acceptable p 16

Westinghouse RAI Response Calculation Conclusions

The in-vessel surveillance capsule and ex-vessel neutron dosimetry data have been provided in WCAP-17669-NP, WCAP 17669 NP, Rev. 0, Appendix C, the measurement-to-calculation (RAPTOR-M3G) comparisons show:

- The in-vessel dosimeters meet the +/-20% criteria for in-vessel surveillance ill capsules l per RRegulatory l G Guideid 1 1.190 190

- The ex-vessel dosimeters meet the +/- 30% criteria for the cavity capsules per Regulatory Guide 1.190.

Further sensitivity study has shown:

- Both the RAPTOR-M3G model used in WCAP-17669-NP, Rev. 0 and the reduced size models have achieved geometrical convergence, g , i.e.,, using g much coarser mesh onlyy changes g the fluence results less than 2%.

- Using different quadrature sets (e.g., S12 vs. S8) only renders less than 3% difference in the calculated fluence values.

17

Thank you !

Questions?

18

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