ISOCS for Free Release

Category: Characterization > Sampling & Analysis Equipments > Analysis Equipment
Reference # : OST/TMS No 2098, DOE/EM-0618 Model No :

The Canberra ISOCS system is designed with the following materials: 55% efficiency germanium detector with a portable liquid nitrogen cryostat (a 5-day Big mac [dewar] Battery – or AC-powered InSpector (a portable spectroscopy analyzer) Adjustable collimeter (shield) Laptop computer with Canberra software (i.e.,Genie-2000 and PROcount) Portable cart for holding the detector along with the associated shielding.The specific detector used in this demonstration has been mathematically prepared by the manufacturer using source measurements and the Monte Carlo process. This allows the user to perform on-site a variety of efficiency calculations for a wide variety of shapes, sizes, densities, and distances between the detector and area of interest. The count time for the detector was set at 15 minutes, however shorter or longer count times may be selected, depending upon the site conditions, in order to meet free-release criteria or other task criteriaOnce in the field the IFR can be operated with or without the collimeter, depending upon the specific application. The collimeter is used to selectively assay areas where contamination may be present.

Benefits

·Nuclide identification and activity provided. Accelerated D& D schedule – shorter final survey times and confirmation of free-release status following D& D activities. In situ near real-time radiological measurements – prompt feedback to measurement team that additional measurements are needed, or to the decontamination team that more work is needed. Less physically demanding (eliminates the need for elevated working conditions) Reduced exposure of personnel to radiation – remote operation of unit after placing it in the area to be surveyed and no time- consuming hand-held instrument surveys are required.

Limitations

A primary limitation is that the IFR technology only detects X and gamma radiation. Nuclides that decay with out X or gamma emission cannot be detected . Nuclides with weak gammas will have higher detection limits, which may not be acceptable. However , for most reactor or Uranium contamination areas there are few of these nuclides and they do not normally determine the releasibitlity of the item or areas, there are few of these nuclides and they do not normally determine the releasibitlity of the item or area. The IFR has not yet been recognized as an approved methodology for performing free-release surveys for buildings at the INEEL. This regulatory/administrative issue currently limits the use of the IFR to confirmatory surveys or hot spot identification.

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The IFR used at the INEEL..

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