Eur. Phys. J. Plus (2022) 137: 248
https://doi.org/10.1140/epjp/s13360-022-02484-2

Regular Article

A hybrid (γ, n) and (n, γ) transmutation study for long-lived fission products and thermal analysis of converter cooling system

¹ Department of Physics, Faculty of Science, Arak University, Arak, Iran
² Nuclear Science and Technology Research Institute, Tehran, Iran

^a b-salajeghe@phd.araku.ac.ir

Received: 18 October 2021
Accepted: 14 February 2022
Published online: 20 February 2022

Abstract

The goal of this work is to optimize the hybrid (γ, n) and (n, γ) transmutation system of long-lived fission products (LLFPs), particularly cesium and technetium, to stable or short-lived nuclei based on an electron accelerator by MCNPX code. Photons and neutrons produced by the interaction of electrons with high atomic number materials create a mixed field. In this study, design parameters such as geometry, materials, target dimensions, and configurations have been optimized to enhance the intensity of mixed field to increase the transmutation rate based on (γ, n) and (n, γ) reactions simultaneously. We have designed a system that uses the photons produced to transmute cesium based on the ¹³⁵Cs (γ, n) ¹³⁴Cs and ¹³⁷Cs (γ, n) ¹³⁶Cs reactions, and the neutrons produced to transmute the technetium based on the ⁹⁹Tc (n, γ) ¹⁰⁰Tc reaction. Furthermore, we have analyzed the temperature of the converter and heat transfer under steady-state thermal (SST) using ANSYS software. The designed system using a duct with a hydraulic diameter of 1.5 cm and 2 m/s for cooling water inlet velocity provides a suitable cooling process with a maximum converter temperature of about 337 °C.