ML20029E941
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| ML20029E941 | |
| Person / Time | |
|---|---|
| Issue date: | 01/27/2020 |
| From: | Cynthia Barr, John Clements, Chris Mckenney, Adam Schwartzman, Bruce Watson Division of Decommissioning, Uranium Recovery and Waste Programs |
| To: | |
| S Giebel | |
| Shared Package | |
| ML20029E935 | List: |
| References | |
| Download: ML20029E941 (12) | |
Text
NUREG-1757, Volume 2, Revision 2 Consolidated Decommissioning Guidance:
Characterization, Survey, and Determination of Radiological Criteria Cynthia Barr, Christepher McKenney, Adam Schwartzman, John Clements, CHP, Bruce Watson, CHP U.S. Nuclear Regulatory Commission Health Physics Society Midyear Meeting / January 27, 2020 1
Working Group Members Regional Staff
- Laurie Kauffman, Region I, Health Physics Inspector
- Michael LaFranzo, Region III, Senior Health Physics Inspector NRC Headquarters Staff
- Cynthia Barr, Senior Risk Analyst
- Greg Chapman, Health Physicist
- John Clements, Health Physicist
- Tony Huffert, Sr. Health Physicist
- Leah Parks, Risk Analyst
- Adam Schwartzman, Risk Analyst 2
NUREG-1757, Volume 2 History
- NUREG-series published: September 2003
- Draft Supplement 1: September 2005
- NUREG-1757, Volume 2, Revision 1: September 2006
- In this new revision
- NRC staff and stakeholder comments collected over the last several years are addressed
- Experience from recent decommissioning projects is added 3
Major Changes to NUREG-1757, Vol. 2
- Dose modeling: updates on conceptual models, source terms, scenarios, and uncertainty analysis
- Radiological surveys: updates on soil reuse and Scenario B
- As Low As Is Reasonably Achievable (ALARA) analysis:
updates based on recent experience
- Composite sampling: new guidance
- Engineered barrier analysis: updates and new references on engineered barrier performance and degradation 4
Dose Modeling
- Conceptualization
- Model abstraction
- Source Term
- Heterogenous distributions
- Consideration of elevated areas
- Scenarios
- Intrusion analyses for buried radioactivity
- Uncertainty analysis
- Correlated parameters
- Risk dilution 5
- Updated guidance on recent studies and lessons learned
- Provides regulatory basis
- Discusses ALARA for unrestricted, restricted, and alternative release
- Discussion enhanced by lessons learned from proposed restricted release scenarios 6
Composite Sampling
- New Appendix O
- Discusses when it would be beneficial to consider composite sampling
- Hard-to-detect radionuclides are present
- Number of samples is cost-prohibitive
- Only interested in mean concentration
- Can be more effective in identifying elevated areas with appropriate modified investigation level (MIL)
- Discusses when it would not be appropriate to use composite sampling and other considerations
- Provides methodology and practical examples 7
Engineered Barrier Analysis
- Several updates since last revision
- Discusses the difference between institutional controls and engineered barriers
- Provides guidance on different forms of model support
- Discusses how engineered barriers can be considered for restricted release and as part of the ALARA process
- Provides updated text and bibliography on evaluation of engineered barrier performance and degradation 8
Radiological Surveys
- Updated guidance:
- Scenario B
- Reuse of soils
- Surveys of excavations
- Dose modeling and radiological survey integration
- Use of graphical tools to visualize data 9
Next Steps
- Send to States for review and comment
- Send to federal partners
- Publish NUREG 10
Conclusions
- NUREG-1757, Volume 2, Revision 2 has been prepared
- New guidance should provide flexibility for complex issues
- Stakeholder input during review and comment period
- Planned for publication this calendar year
- After publication, the NRC staff would like feedback on how it could be improved further, for future revisions 11
Speaker Contact Information Cynthia S. Barr cynthia.barr@nrc.gov 301-415-4015 12