ML20029E943

GEH Vallecitos Radiation Surveys 01-27-2020

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: ML20029E936 ML20029E937 ML20029E938 ML20029E940 ML20029E941 ML20029E942 ML20029E943 ML20029E944 ML20029E945 NUREG-1507, 01-29-2020 Wide r3
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 3

• 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

Outdoor Surveys 4

Outdoor Surveys 5

• 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

Indoor Surveys 6

Indoor Surveys 7

• 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

8 Inspection Procedure 83750 ADAMS Accession No. ML19270D454

Indoor Surveys 9

• 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

Indoor Surveys 10

• 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

11 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

Conclusions 12

• 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

Speaker Contact Information 13 Tony Huffert, CHP anthony.huffert@nrc.gov 301-415-2468