ML23318A216
| ML23318A216 | |
| Person / Time | |
|---|---|
| Issue date: | 11/21/2023 |
| From: | Michele Sampson NRC/RES/DE |
| To: | Beverly Smith NRC/NRR/DNRL |
| Carol Nove 301-415-2217 | |
| Shared Package | |
| ML23318A214 | List: |
| References | |
| NRR-2022-007 | |
| Download: ML23318A216 (3) | |
Text
November 21, 2023 MEMORANDUM TO: Brian Smith, Director Division of New and Renewed Licenses Office of Nuclear Reactor Regulation Signed by Sampson, Michele FROM: Michele Sampson, Director on 11/21/23 Division of Engineering Office of Nuclear Regulatory Research
SUBJECT:
IMPENDING PUBLICATION OF THE TECHNICAL PAPER ENTITLED DEVELOPMENT AND TESTING OF COARSE-GRAINED MODELS FOR ULTRASONIC SIMULATIONS OF CAST AUSTENTIC STAINLESS STEEL (NRR-2022-007)
The Office of Nuclear Regulatory Research (RES) has completed the enclosed technical paper for the journal Ultrasonics entitled Development and Testing of Coarse-grained Models for Ultrasonic Simulations of Cast Austenitic Stainless Steel under contract with Pacific Northwest National Laboratory (PNNL). The paper may be found in ADAMS at Accession ML23318A217 and online in the journal Ultrasonics at https://doi.org/10.1016/j.ultras.2023.107157. This paper documents work performed under User Need Request (UNR) NRR-2022-007, User Need Request for Evaluating the Reliability of Nondestructive Examinations. This UNR focused on assessing the reliability and effectiveness of nondestructive examination (NDE) methods used in nuclear power plant inservice inspections. Task 1 on Modeling and Simulation requested that RES establish a standard method for evaluating ultrasonic testing (UT) modeling and simulation results for a variety of materials and degradation mechanisms.
Modeling and simulation for UT may be used to help address key aspects of the UT, including probe design, focal law development, and inspection coverage predictions. Coarse-grained microstructures present significant challenges to the examinations as well as to modeling the examinations due the existence of large numbers of grain interfaces and crystalline orientations of the grains. In this technical paper, PNNL documents an approach where polished and chemically etched cast austenitic stainless steel (CASS) sections were used as the foundation to create realistic models of coarse-grained microstructures. A second modeling method using Voronoi regions was also used to model the CASS microstructure. Empirically measured sound fields were compared to simulated sound fields, and the sound field scatter and attenuation were quantitatively compared for both the realistic and the Voronoi models. Results showed that both modeling approaches resulted in predictions of sound-field scatter that were comparable to that observed in the empirical data. However, attenuation and beam partitioning observed in the Voronoi models agreed better with the empirical data.
CONTACT: Carol Nove, RES/DE/MEB (301) 415-2217
B. Smith 2 The study concluded that it is possible to model CASS, but that the models should not be considered representative of a particular CASS morphology, since the CASS microstructure can change significantly from specimen to specimen or even within one specimen. PNNL recommended that to obtain meaningful results for models of coarse-grained specimens, ensembles of simulations should be used.
Staff representatives from the Division of New and Renewed Licenses in the Office of Nuclear Reactor Regulation (NRR) reviewed a draft of this paper and stated, The technical paper is of very high quality. The technical paper shows the complexities involved in the use of ultrasonic modeling in CASS and the comparison to laboratory results.
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 public release of this paper, please contact Carol A. Nove of my staff at 301-415-2217 or can2@nrc.gov.
Enclosure:
As stated
ML23318A214; Memo ML23318A216 OFFICE RES/DE/CIB RES NSIR/DPCP/RSB NAME CNove CN SRuffin SR MSampson MS DATE Nov 16, 2023 Nov 17, 2023 Nov 21, 2023