Neutron dose equivalent estimation from the specific activity of 51Cr

The exposed neutron dose from the JCO criticality accident has been preliminarily estimated from data on the specific activity of induced 51Cr using the Monte Carlo N-Particle Transport Code version 4B. The dependence on ground distance of the measured specific activities is fitted to the results of the transport calculation. The neutron dose equivalents for ground distances of 130–450 m from the JCO range from 36 to 1 mSv.