A NEW DOSE ASSESSMENT METHOD FOR THE UK SYSTEM OF CRITICALITY ACCIDENT DOSIMETRY

摘要

A new method for the measurement and interpretation of the Harwell criticality accident dosemeter has been developed. The new method treats the dosemeter components as individual detector elements with unique energy-dependent response functions generated with MCNP6. A bespoke deconvolution code was written that generates a parameterized neutron spectrum from the integral activities in each detector element. The spectrum can be folded with any set of fluence-to-dose conversion coefficients to determine an integral dose. The new method has been validated computationally using realistic neutron spectra and experimentally in a series of test irradiations using the Godiva-Ⅳ, CALIBAN and PROSPERO critical assemblies. The method was able to reproduce the true dose with a small positive bias and a combined relative uncertainty of 25 % across the full range of spectra considered (10 pGy cm~2 to 45 pGy cm~2).