ML22311A008
| ML22311A008 | |
| Person / Time | |
|---|---|
| Issue date: | 11/17/2022 |
| From: | Louise Lund NRC/RES/DE |
| To: | Beverly Smith NRC/NRR/DNRL |
| Carol Nove 301-415-2217 | |
| Shared Package | |
| ML22311A007 | List: |
| References | |
| PNNL-33625, UNR NRR-2020-002 | |
| Download: ML22311A008 (3) | |
Text
MEMORANDUM TO:
Brian Smith, Director Division of New and Renewed Licenses Office of Nuclear Reactor Regulation FROM:
Louise Lund, Director Division of Engineering Office of Nuclear Regulatory Research
SUBJECT:
IMPENDING PUBLICATION OF TECHNICAL LETTER REPORT ENTITLED ULTRASONIC MODELING AND SIMULATION STATUS UPDATE, PART 1: FLAW RESPONSE SIMULATIONS USING FLAW PROFILES, AND PART 2:
REVIEW OF ONSCALE SIMULATION SOFTWARE (PNNL-33625) (UNR NRR-2020-002)
The Office of Nuclear Regulatory Research (RES) has completed a technical letter report entitled Ultrasonic Modeling and Simulation Status Update, Part 1: Flaw Response Simulations using Flaw Profiles, and Part 2: Review of OnScale Simulation Software, (ADAMS Accession ML22311A009) under contract with Pacific Northwest National Laboratory (PNNL). This Technical Letter Report (TLR) documents work performed under User Need Request (UNR)
NRR-2020-002, Update of the User Need Request for Evaluating the Reliability of Nondestructive Examinations of Vessels and Piping. This UNR focused on assessing the reliability and effectiveness of nondestructive examination methods used in nuclear power plants. Task 1 on ultrasonic (UT) modeling and simulation requested that RES establish a standard method for evaluating UT modeling and simulation results for a variety of materials and degradation mechanisms.
The work documented in this TLR is part of a multi-phase effort at PNNL under UNR Task 1 to evaluate UT modeling and simulation performance, reliability, and accuracy, and define best practices required for using computational models to simulate UT testing scenarios being conducted on nuclear power plant components. Simulation results from UT models can inform the design and qualification of inspection techniques and help interpret inspection results.
This TLR is divided into two parts. Part 1 addresses flaw-response simulations in CIVA using flaw profiles obtained by destructive testing of austenitic welds. For this portion of the work, the simulated flaw responses were compared to flaw responses from empirical scans of the same welds using the same probes as those modeled. Part 2 describes an assessment of a commercially available finite element modeling and simulation package called OnScale.
CONTACT:
Carol Nove, RES/DE/MEB (301) 415-2217 November 17, 2022 McKirgan, John signing on behalf of Lund, Louise on 11/17/22
B. Smith This work will be used to provide guidance when establishing methods to perform and evaluate simulations for more standardized model implementation, simulation analysis, and interpretation of results.
The results of part 1 showed that the simulation accuracy did not benefit in a statistically meaningful way from using a realistic weld model. Thus, when actual flaw geometries and weld microstructures are unknown, the results suggest that, instead of focusing on a specific weld model or flaw geometry, efforts to determine a range of flaw responses would be more useful.
Further, this work showed that parametric studies or CIVA metamodels can be used effectively to explore the effects of varying flaw properties such as through-wall depth, tilt and ligament.
In part 2, OnScale simulations were performed, and results were compared to those of similar simulations in CIVA and to empirical data. Overall, results of OnScale and CIVA simulations were similar for isotropic material models. Simulations through an austenitic weld model showed the largest differences between the modeling platforms with CIVA showing much more scatter than OnScale. Both platforms had similar beam characteristics on the far side of the weld.
Staff representatives from the Division of New and Renewed Licenses in the Office of Nuclear Reactor Regulation (NRR) reviewed a draft of this TLR and stated, The NRR staff agrees with the conclusions of the report and the key findings. The TLR is of very high quality and is a good interim report on the research. The TLR shows the complexities involved in the use of ultrasonic modeling and provides detailed technical guidance for the use of modeling. The TLR contains sufficient detail and rigor to be used as a reference in rulemaking and in evaluating proposed alternatives.
RES has established an online quality survey to collect feedback from user offices on the usefulness of RES products and services. This survey can be found online at the hyperlink:
RES Quality Survey. I would appreciate the responsible manager or supervisor completing this short survey within the next 10 working days to present your offices views of the delivered RES product.
If additional information is required, or there are any concerns with the impending public release of this TLR, please contact Carol A. Nove of my staff at 301-415-2217 or can2@nrc.gov.
Enclosure:
As stated
ML22311A007; Memo ML22311A008 OFFICE RES/DE/CIB RES RES/DE NAME CNove SRuffin LLund JMcKirgan for DATE Nov 16, 2022 Nov 16, 2022 Nov 17, 2022