ML20029E943
| ML20029E943 | |
| Person / Time | |
|---|---|
| Issue date: | 01/27/2020 |
| From: | Shaun Anderson, Jeff Griffis, Huffert T, Jack Parrott, Chris Steely, Bruce Watson Division of Decommissioning, Uranium Recovery and Waste Programs |
| To: | |
| S Giebel | |
| Shared Package | |
| ML20029E935 | List: |
| References | |
| Download: ML20029E943 (13) | |
Text
NRC Radiological Surveys at the GE-Hitachi Vallecitos Nuclear Center Tony Huffert, CHP Stephanie Anderson, Jeff Griffis, CHP Jack Parrott, Chris Steely, Bruce Watson, CHP U.S. Nuclear Regulatory Commission
Vallecitos Nuclear Center 2
Site History
- Three reactor facilities in SAFSTOR
- VBWR (1965), EVESR (1970), GETR (1986)
- Supported AEC, civilian nuclear power research
- Range of fuels for experiments, development and isotope production
- Extent of dismantlement varies at each facility 3
Outdoor Surveys 4
Outdoor Surveys
- Licensee classified land areas as non-impacted
- Radiation surveys not required
- NRC verified classification by reviewing site history and conducting independent confirmatory surveys
- Lessons learned
- Tilling of soils complicates survey data analysis
- Local "background" data important 5
Indoor Surveys 6
Indoor Surveys
- NRC routinely conducts inspections at facilities in SAFSTOR
- Inspection Procedure 83750 for occupational radiation exposure inspections
- Radiation survey program needs to account for current radiological conditions
- Performance of decommissioning activities
- Routine entries into containment 7
Inspection Procedure 83750 ADAMS Accession No. ML19270D454 8
Indoor Surveys
- Radiological source term data should be well characterized and up to date
- Historic and current data should be assessed
- Trends in radiological conditions
- Postings of radiation areas
- Airborne radiation hazards
- Potential for contamination migration 9
Indoor Surveys
- Instrument efficiencies must account for current radiological conditions being surveyed
- Low energy betas and transuranics
- Use of smears and volumetric samples to assess radionuclide mixtures throughout facility
- Wet and dry smears
- Concrete samples 10
Indoor Surveys
- Document facility aging management issues
- Structural degradation, water intrusion
- Determine if radionuclides are migrating, including subsurface (decommissioning planning rule requirements)
- Maintain safety culture as if operating
- New decommissioning activities, aging facilities, changing source terms may pose challenges
- Radiation and non-radiation hazards 11
Conclusions
- Outdoor surveys
- Adequate data on local background variability
- Documentation of site history should include soil tilling practices
- Indoor surveys
- 10 CFR Part 20 radiation survey, posting, airborne hazard requirements
- Facility conditions
- Non-radiation hazards 12
Speaker Contact Information Tony Huffert, CHP anthony.huffert@nrc.gov 301-415-2468 13