Environmental and personnel monitoring for uranium by delayed neutron counting.

At the Imperial College Reactor Centre we have developed a fully automated, large sample, high sensitivity delayed neutron counting system for routine analysis of environmental samples and personnel monitoring. Two-hundred fifty samples with a maximum volume of 30 ml can be analysed each working day. The detection limits (3 sigma) for uranium of natural isotopic abundance in our routine samples are typically 1 microgram/kg (0.