ML21257A218
| ML21257A218 | |
| Person / Time | |
|---|---|
| Issue date: | 09/16/2021 |
| From: | Matthew Hiser Office of Nuclear Regulatory Research |
| To: | |
| Anchondo I | |
| Shared Package | |
| ML21257A217 | List: |
| References | |
| Download: ML21257A218 (16) | |
Text
NRC Draft Guidelines Document -
Laser Powder Bed Fusion ML21074A040 Matthew Hiser Office of Nuclear Regulatory Research September 16, 2021
Outline
- Overview of Laser Powder Bed Fusion (LPBF)
- Technical Basis for LPBF Draft Guidelines Document (DGD)
- Tie to Draft AMT Review Guidelines (Table 1)
- LPBF Technical Review Guidelines
- Table 2A: material-generic process topics
- Table 2B: 316L material-specific properties / performance topics
- Conclusions 2
Laser Powder Bed Fusion
- Process:
- Uses laser to melt or fuse powder together in bed of powder
- Generally, most advantageous for more complex geometries
- Potential Applications
- Smaller Class 1, 2 and 3 components, fuel hardware, small internals https://www.osti.gov/pages/servlets/purl/1437906 3
Technical Basis for LPBF Guidelines AMT-Specific (Initial 5 AMTs) Generic
- DGD is based on two technical documents Technical Regulatory Guidelines (ML20351A292) produced under Subtask 1A: (Subtask 1A)
Technical Technical (draft for public comment)
Draft Guidelines
- Technical letter report from Oak Ridge National Letter Report LPBF Assessment LPBF Document LPBF Laboratory (ORNL)
ML20351A292 ML20351A292 ML21074A040 Draft Technical Technical
- NRC staff technical assessment of LPBF Guidelines Letter Report Assessment Document L-DED L-DED L-DED Subtask 2C Technical Draft Draft Review Final Technical Guidelines Guidelines for Assessment Guidance for
- DGD builds on the NRC technical assessment Letter Report Document AMTs Cold Spray Cold Spray Cold Spray Initial AMTs ML21074A037 and provides guidelines, when finalized, to the Draft Technical Technical Guidelines Letter Report Assessment Document Expected to NRC staff by identifying important PM-HIP PM-HIP PM-HIP be Legend Contractor-developed Draft developed considerations when reviewing a submittal Technical Technical Guidelines Letter Report Assessment Document later after NRC Staff-developed EBW EBW EBW DOE-EPRI requesting the use of LPBF demo project 4
LPBF Technical Basis Documents
- Technical letter report on LPBF from ORNL
- Documents the current state of LPBF with respect to material microstructures and properties relative to conventional manufacturing
- Identifies technical and codes and standards gaps in ensuring quality and sufficient properties and performance for LPBF-fabricated components
- NRC staff technical assessment
- Provides context to the gaps identified in the ORNL report from NRCs perspective
- Considers other relevant technical information, such as NRC regulatory and research experience, technical meetings and conferences, codes and standards activities, EPRI and DOE research products
- Highlights key technical information related to LPBF-fabricated components in nuclear applications 5
Use of the Term Safety Significance
- The safety significance of each identified difference/topic in the LPBF DGD refers to the impact on component performance.
- The overall impact to plant safety is a function of component performance and the specific component application (e.g., its intended safety function).
- The LPBF DGD and its supporting documents do not address the impact on plant safety, as such an assessment would not be possible without considering a specific component application.
- In addition to the technical review guidelines in the LPBF DGD, the NRC staff should consider the specific component application and the potential for secondary consequences, such as debris generation and associated impacts, when assessing the impact to overall plant safety.
6
Tie to Draft AMT Review Guidelines (Table 1)
Process Supplemental Production Process Performance Difference / Topic Qualification Testing Control and Verification Monitoring Process-Driven: LPBF machine process control, Powder quality, LPBF build process management and control, X X Witness specimens, Post-processing, Weldability and Joining Process and Properties: Local geometry impacts on component properties and performance, Heterogeneity and X X anisotropy in properties, Residual stress, Porosity, Surface finish, Tensile properties, Initial fracture toughness Performance under Aging: Thermal aging, SCC, Fatigue, Irradiation effects, High Temperature Time- Dependent X X Aging Effects, Weld integrity
- The applicable primary elements may vary on a case-by-case basis, depending on the licensees approach to demonstrating quality and safety.
- Table 1 provides an example of applicable elements and reflects that not every element in Appendix A to the draft AMT review guidelines is applicable to every difference listed in Table 1.
7
Tables 2A and 2B
- Tables 2A and 2B provide the technical review guidelines
- Material-generic vs. material-specific
- Table 2A lists the generic differences / topics (generally process focused)
- Table 2B lists the material-specific (generally properties and performance focused) differences / topics for LPBF 316L stainless steel
- Differences identified in Table 2B involving material-specific properties and performance would likely need to be considered for any newly fabricated material (316L or not) using LPBF
- In general, material-specific data are important for any nuclear LPBF-fabricated component to ensure adequate component performance in the applicable environment 8
Content of Tables 2A and 2B
- Difference
- Lists the differences between LPBF and traditional manufacturing identified in the NRC technical assessment
- Key Technical Information
- Summarizes the key technical information documented in the NRC technical assessment for easy reference
- Technical Review Guidelines
- Provides additional guidelines related to the differences between LPBF and traditional manufacturing that the staff should consider when evaluating how a licensees or applicants submittal addresses the differences between LPBF and traditional manufacturing 9
DGD Examples - Table 2A, Process-Driven 10
DGD Examples - Table 2A, Process and Properties 11
DGD Examples - Table 2B, Process and Properties 12
DGD Examples - Table 2B, Performance under Aging 13
DGD Examples - Table 2B, Process-Driven 14
Conclusions
- First AMT technology-specific DGD has been developed as a "draft not for use" for LPBF
- The DGD builds on the ORNL technical letter report and NRC staff technical assessment to provide the technical review guidelines and associated key technical information
- The LPBF DGD is consistent with the draft AMT review guidelines and addresses the same primary elements
- Technology-specific DGDs are anticipated to be incorporated in some form into the final AMT guidance, perhaps as additional appendices
- Additional DGDs for remaining AMTs expected to be developed as a "draft not for use" and shared for public feedback 15
Questions ?????
16