An estimation of fast neutron flux by 35Cl(n, α)32P reaction

Phosphorus-32 produced by the Cl-35(n, alpha)(32)p reaction in table salt and KCl was measured to estimate the fast neutron flux from the JCO criticality accident. A directional dependence of the fast neutron flux was suggested by the anomalously low activities of samples collected from the south and south-west directions. Although the present data are preliminary, the total number of fast neutrons from the precipitation vessel is estimated to have been approximately 5 x 10(16) using both the P-32 activity at 70m and the observed attenuation constant (0.006 m (-1)). (C) 2000 Elsevier Science Ltd. All rights reserved.