Lessons Learned on the Presentation of Scan Data.

Technicians performed a radiological survey of a surplus metal tank to support disposition planning at an Oak Ridge, TN, site. The survey included radiation scans to identify contamination and, if identified, define the boundary and magnitude of contamination. Fixed-point 1-min measurements were also collected at randomly selected locations for comparison against the site's free release limit of 5,000 disintegrations per minute per 100 cm (dpm 100 cm) (0.83 Bq cm). Scan data were recorded using a data logger as a means to document surveyor observation-logged data captured at 1-s intervals and converted to counts per minute (cpm) by the data logger software were presented in the project report. Both the qualitative scan data (in cpm) and the quantitative direct measurements (in dpm 100 cm) were reported for completeness, so stakeholders had all available information to support disposition decisions. However, a new stakeholder-introduced to the project at the reporting phase of work-used the instrument efficiency and background data to convert the scan data from cpm to dpm 100 cm, then compared the converted results to the site limit. Many of the converted values exceeded 5,000 dpm 100 cm. This resulted in delays in tank disposition and additional project costs that could have been avoided if the proper use and interpretation of scan data and implications of radon progeny buildup on oxidized metal surfaces had been better communicated.