Monitoring of surface alpha contamination with inexpensive passive monitors
- Oak Ridge National Lab., TN (United States)
- Landauer Inc., Glenwood, IL (United States)
- Rad Electric Inc., Frederick, MD (United States)
Field applications are presented in the monitoring of indoor and outdoor surface alpha contamination using passive devices. Both small alpha track and larger electret devices were used. Sensitivity is such that passive measurements made in one to two hours produce 10:1 signal-to-noise readings at a proposed release level of 220 dpm/100 cm{sup 2} (3.7 Bq/cm{sup 2}). The small alpha track detectors can be deployed in cracks, under doors, inside narrow pipes and other difficult to access locations where contaminated dirt collects and resists easy removal. Examples are given of the mapping of alpha contamination on floors and metal flanges. Track detectors can also provide spatially resolved information on a fine scale and recognize micron-sized particulate contamination. Soils contaminated with low-level plutonium produce readily measurable voltage drops of 1--5 v/h with 2 g samples containing 5--27 pCi/g, respectively. The electret device has the advantage of allowing readout immediately after exposure using a portable voltmeter. Processing of the exposed plastic track detector requires chemical etching and optical counting to obtain the density of etch tracks but provides a permanent record of an exposure. Both types of devices will find numerous applications in decontamination and decommissioning.
- Research Organization:
- Oak Ridge National Lab., TN (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 10191180
- Report Number(s):
- CONF-9210194--2; ON: DE93001636
- Country of Publication:
- United States
- Language:
- English
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