Neutron Dose Determination in Criticality Accidents by Gamma Counting of the Patient's Dental Fillings

Since most people have some teeth filled with the normal mercury-silver (Hg 50%, Ag 30%) alloy, an attempt has been made to determine the neutron dose received in a criticality accident by counting the activity of the amalgam due to (n, γ) reactions. Thermal neutron doses less than about 10 rads can be estimated by measuring the induced activity in mercury or copper (which is present in trace quantities in the amalgam) and doses less than about 20 rads can be estimated by measuring the induced activity in silver. The method gives an approximate result half a day after the accident and a more accurate result can be obtained after a few days. The method, in combination with the film dosimeter and other standard methods, may help to give a more complete idea of the dose received by a person in a criticality accident. (author)