Topsoil radiological characterisation of L-54M reactor surroundings preliminary to decommissioning operations

Abstract

The radiological characterization of the topsoil of the L-54M reactor surroundings carried out in this work aims at obtaining the reference blank point for the forthcoming decommissioning operations and ascertain if unexpected radionuclide release occurred during the operational life of the plant. Standardised methods have been employed in order to collect representative samples and reliable results. Suitable sample pre-treatment procedures were applied. Gamma and beta spectrometric analyses were carried out to measure the activity concentrations of ⁶⁰Co ¹³⁷Cs, ¹⁵²Eu, ²⁴¹Am and ⁹⁰Sr. These have been considered as representative radionuclides that could have been originated from reactor operations and that could still be present at four decades post reactor shutdown.

Keywords: Decommissioning; Radiological characterization; Research reactor; Topsoil.