The Nuclear Regulatory Commission is issuing a request for information (RFI) aimed at understanding the current state-of-art radiological survey methods used to comply with decommissioning and license termination requirements. According to the commission, the information will help its staff better understand trends in radiological survey instrumentation and data analysis, including those used to survey both surface and subsurface residual radioactivity.
“Owing to significant technological advancements over the past two decades, NRC licensees have increasingly used, or plan to use, more modern and updated survey instrumentation and data capture tools, including use of global positioning system, light detection and ranging, and geographic information system technologies,” the NRC said in announcing the RFI in the May 4 Federal Register.
Comments on the RFI are due by June 5.
Specific questions: The NRC is asking for comments on general questions from stakeholders, including nuclear licensees, professional organizations, nuclear industry consultants, vendors, academic researchers, and interested individuals.
The NRC said it will use responses to the questions to develop guidance in the areas of continuously collected radiological survey data without a surveyor listening to the audible output, and subsurface survey design optimization and data analysis to support decommissioning decision-making.
Respondents can answer as many of the following 10 questions as they wish.
Questions related to continuously collected data surveys without a surveyor listening to the audible output:
- What types of system or equipment (i.e., instrumentation, including radiation detectors, and software) do you use or plan to use to record radiation detector location and raw instrument response?
- What methods do you use to calculate scan minimum detectable concentrations to ensure sufficient sensitivity to detect risk-significant levels of residual radioactivity or to better understand measurement uncertainty?
- What methods have you used to post-process data to identify areas for follow-up investigation (e.g., use of radiation surveys maps, and statistical tests and measures to identify anomalous radioactivity to be targeted for follow-up investigation)?
- Have you experienced technical issues with data collection and analysis during previous surveys and what methods did you use to troubleshoot those issues? Do you have any lessons learned you could share related to the technical issues?
- What areas do you see as challenges or gaps to radiological survey design and data analysis that could be addressed in future guidance (e.g., a priori scan minimum detectable concentrations calculation) or tool development (e.g., data integration and post-processing)?
Questions related to subsurface survey design and data analysis:
- What types of instrumentation and approaches do you use to collect subsurface radiological survey data in the field? Specifically, what types of instrumentation and approaches has your organization used to perform surveys of hard to access locations in the subsurface (embedded piping, sumps, soils located at depth or underneath buildings, and bedrock)?
- What types of methods and software (e.g., geophysical methods and related software) have been used and subsurface data (e.g., hard and soft data) have been collected, and what novel approaches have been used to combine or condition data to develop site conceptual models or mathematical models, or to show release criteria have been met?
- What statistical approaches have you used to show subsurface residual radioactivity meets release standards including consideration of uncertainty (e.g., number and depth of samples, type of data and statistical approaches used to demonstrate compliance)?
- What approaches have you used to optimize subsurface survey designs including initial scoping to final status survey designs (e.g., geometrical or geostatistical techniques)?
- What areas do you see as challenges or gaps with respect to subsurface surveys and data analysis that could be addressed in future guidance or tool development?