ML25006A085
| ML25006A085 | |
| Person / Time | |
|---|---|
| Issue date: | 01/15/2025 |
| From: | Gregory Chapman Reactor Decommissioning Branch |
| To: | |
| References | |
| DUWP-ISG-03 | |
| Download: ML25006A085 (1) | |
Text
1 DUWP-ISG-03 CONTAMINATION CONTROL, RADIOLOGICAL SURVEY, AND DOSE MODELING CONSIDERATIONS TO SUPPORT LICENSE TERMINATION AT SITES WITH ENVIRONMENTAL DISCRETE RADIOACTIVE PARTICLE CONTAMINATION Greg Chapman PE, CHP Sr. Health Physicist NMSS/DUWP/RDB NRC Decommissioning Lessons Learned Workshop January 15, 2025
2 What is a Discrete Radioactive Particle?
Small particle/object that has a relatively high activity and is insoluble in water
- "Hot Particles" generated during operations
- Fuel fleas from fuel rod failures
- Activated metals from reactor vessel internal component wear
- May be held up in systems being dismantled during decommissioning
- "Chips" from decommissioning segmentation efforts
- Activated metal segmentation
- Reactor vessel
- Internal components
- Bioshield rebar
- Activated concrete
- Bioshield demolition A concern for skin contaminations during dismantling Assessing risk for license termination if released to the environment
3 DRPs vary in size ranging from less than visible to small rocks
Why the concern?
- DRPs can be
- Very mobile
- Difficult to detect/identify
- Even harder if covered by soil/debris or under water
- A point source vs area source
- If DRPs are present at license termination
- How to assure public risk is consistent with regulations/guidance
- Potential exposure to particles cannot be assessed using typical decommissioning codes (RESRAD or DandD) 4
DUWP-ISG-03 focus
- Prevention is Key
- Emphasis is on Contamination Control
- Timely and appropriate remediation of DRPs
- Detection sensitivity methods for scanning for point sources
- DRPs should be collected, assessed, and disposed
- Assessing Potential Dose/Risk of Public Exposure from a DRP to risk inform license termination decisions 5
DUWP-ISG-03 Schedule
- Draft DUWP-ISG-03 issued for comment in early September 2024
- Significant comments
- Activity associated with very small risk significant DRPs may be too low to detect
- Is the NRC developing new criteria?
- International scientific consensus should be established for DRP dose modeling
- Final DUWP-ISG-03 expected to be released in early 2025 6
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