ML20029E941
| 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 3
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
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 5
- Conceptualization
- Model abstraction
- Source Term
- Heterogenous distributions
- Consideration of elevated areas
- Scenarios
- Intrusion analyses for buried radioactivity
- Uncertainty analysis
- Correlated parameters
- Risk dilution
ALARA 6
- 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
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 7
- 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
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 11 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
Speaker Contact Information 12 Cynthia S. Barr cynthia.barr@nrc.gov 301-415-4015