Position-Sensitive Radiation Monitoring (Surface contamination Monitor)

Category: Characterization > Monitors > Multipurpose Detectors
Reference # : OST No 1942 , DOE/EM-0433 Model No : SCM /SIMS

The SCM/SIMS is a motorized characterization and data analysis system for surveying alpha and beta contamination on floor and wall surfaces. Utilizing a position-sensitive, gas-proportional counter (PSPC), 400 radiation measurements are taken in an area of 1 sq. meter. Survey data and sample location are logged electronically as well as displayed on an LCD screen for the operator. The data from each survey is analyzed by the SIMS to obtain visual representations of the surfaces surveyed, to generate a data report detailing the actual numerical results, and to overlay the data into a CAD drawing. This system is also capable of producing 2-dimentional and pseudo 3-dimensional surface plots of hot spot locations and the associated radiological measurements in units of cpm (or efficiency-correct units of dpm) The detect both beta/gamma and alpha radiation fieldsThe results of this demonstration are currently being analyzed to determine the effectiveness of the system compared to baseline manual surveys, which ranged from free release levels to greater than 700,000 dpm per 100 cm2 in the surveyed area. Dimensions of Tech Model (LxWxH):Weight of Tech Model (lb):75-150 lb

Benefits

Ability to capture both alpha and beta/gamma information for all surfaces surveyed with one detector. This detector is equivalent to an assembly of many baseline detectors, providing more accuracy and completeness at higher scanning speeds. Reports can be generated automatically that provide a more clear, concise and understandable representation of exactly where and how much contamination is present. The data can be used for job planning and decontamination activities, as well as loading into dose assessment software packages, with more accuracy, completeness, speed and reproducibility than with the baseline technology. All information acquired with the system is scientifically derived, and not subject to a technician's subjective observations. The data are electronically logged, and are not recorded manually Efficient, automatic production of reports using standard word processing software coupled with two-dimensional color imagery of the area surveyed Ability to correlate contamination levels to specify locations Ability to collect and store continuos radiological data in a database format A position-sensitive detection system that registers locations of radioactivity

Limitations

Due to physical and geometric of the PSPC, near -corner and wall measurements could not be obtained in one pass; as secondary perpendicular to the first was needed. Near- corner and wall measurements may also be accomplished by changing to a detector with a right angle At the present time, there is no need to modify the system demonstrated at the Hanford Site C Reactor The system is not suitable for high-contamination/radiation areas because of its sensitivity of electronic components, circuits and size Considering the sensitivity of the system, alpha detentions may need confirmatory measurements with a hand-held detector The innovative technology is not recommended for use in high-radiation areas, due to the sensitivity of electronic components and circuits

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Pictures

	Shonka Research Associates, Inc.’s surface contamination monitor.
	Position-Sensitive Radiation Monitor
	The schematic for the SCM/SIMS system

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