Monte Carlo optimum management of 241Am/Be disused sealed radioactive sources

Cebastien Joel Guembou Shouop,Eric Jilbert Nguelem Mekongtso,Maurice Ndontchueng Moyo,Augustin Simo,David Strivay,Serge Mbida Mbembe,Jean Felix Beyala Ateba,Cedric Tayou Kamkumo

doi:10.1038/s41598-022-05221-y

Cebastien Joel Guembou Shouop, Eric Jilbert Nguelem Mekongtso + Show 6 more

Open Access

https://doi.org/10.1038/s41598-022-05221-y

Copy DOI

Abstract

The optimum encapsulation of 241Am/Be disused sealed radioactive sources (DSRS) based on PHITS Monte Carlo simulations for their long-term storage in Cameroon was performed. The country capacity for the management of disused neutron sources was also evaluated and showed that a Am1 P60 capsule is sufficient for the total available inventoried 241Am/Be DSRSs. The effective dose rate was computed in the enclosures of the DSRS container, which will be temporarily stored in the centralized radioactive waste facility. The obtained results were in agreement with the ALARA principle for the exposure rate optimization and the obtained exposure dose rates were found to be 1.830 μSv/h (horizontal calculation) and 0.137 μSv/h (vertical computation) which values are lower than the 2.5 μSv/h acceptable limit for the public area. The dose profile for 241Am/Be source obtained, the neutron flux, and gamma generated from neutron absorption showed agreement with the research hypothesis. The Monte Carlo assessment achieved in the present research will be useful for dismantling and preparing the waste package for long-term storage.

Highlights

The optimum encapsulation of 241Am/Be disused sealed radioactive sources (DSRS) based on Particle and Heavy Ion Transport code System (PHITS) Monte Carlo simulations for their long-term storage in Cameroon was performed
The neutron flux is highest at the 241Am/Be source position which is confined at the Am1 P60 capsule center
The optimum encapsulation of 241Am/Be disused sealed radioactive sources based on PHITS Monte Carlo simulations for the long-term storage of DSRSs in Cameroon was performed

Summary

Introduction

The optimum encapsulation of 241Am/Be disused sealed radioactive sources (DSRS) based on PHITS Monte Carlo simulations for their long-term storage in Cameroon was performed. The country capacity for the management of disused neutron sources was evaluated and showed that a Am1 P60 capsule is sufficient for the total available inventoried 241Am/Be DSRSs. The effective dose rate was computed in the enclosures of the DSRS container, which will be temporarily stored in the centralized radioactive waste facility. One of the management options is to send back to the manufacturers DSRS that cannot be used but at time, this option is not possible and the country where it was being used should develop its own management capability Safe management of these disused low activity radioactive sources has been a great challenge especially for neutron sources where shielding requires appropriate materials. Monte Carlo simulations are used to optimize the DSRS disposal containers with a view to reduce the high radiological risk to the population and to the radioactive waste management staff

Methods

Results

Conclusion