The Canadian whole body counting intercomparison program: a summary report for 1989-1993.

The Human Monitoring Laboratory, which is the Canadian National Calibration Reference Centre for In-Vivo Measurements, has been conducting an annual intercomparison program for whole body counting facilities since 1989. Each year a number of phantoms are prepared for participants to measure the accuracy, precision, size dependency, and identification capabilities of their whole body counters. Other tests are designed to measure the sensitivity of the whole body counter to geometry factors. Some phantoms are prepared with the same radionuclide from year to year so that time dependent data can be acquired, whereas other phantoms are prepared as unknowns. This article describes the tests that were performed, gives the results for Canadian participants, and compares the results to interim performance criteria. Measurement results from a human volunteer who ingested 137Cs contaminated caribou meat and was counted at a number of facilities in 1990 are also presented.