Feasibility study of nuclear transmutation by negative muon capture reaction using the PHITS code

Shin-Ichiro Abe,Tatsuhiko Sato

doi:10.1051/epjconf/201612204002

Abstract

Feasibility of nuclear transmutation of fission products in high-level radioactive waste by negative muon capture reaction is investigated using the Particle and Heave Ion Transport code System (PHITS). It is found that about 80 % of stopped negative muons contribute to transmute target nuclide into stable or short-lived nuclide in the case of 135 Cs, which is one of the most important nuclide in the transmutation. The simulation result also indicates that the position of transmutation is controllable by changing the energy of incident negative muon. Based on our simulation, it takes approximately 8.5 × 10 8 years to transmute 500 g of 135 Cs by negative muon beam with the highest intensity currently available.

Highlights

Partitioning and transmutation (P&T) have been investigated to reduce the radiotoxicity and storage time of the high-level radioactive waste (HLW) [1,2,3,4,5]
In the P&T process, HLW is separated into below groups; minor metals (e.g., Ru, Rh, Pd), minor actinides (MA), Sr and Cs, and the other fission products (FPs)
The time required to transmute of all FPs can be estimated briefly as follows: t where NA is the Avogadro’s number, g is the content of the FP in spent fuel, M is the mass number of the target FP, α is the transmutation ratio to stable or short-lived nucleus, and φ is the intensity of negative muon

Summary

Introduction

Partitioning and transmutation (P&T) have been investigated to reduce the radiotoxicity and storage time of the high-level radioactive waste (HLW) [1,2,3,4,5]. The unique feature of negative muon capture reaction is the controllability of capture position. A negative muon is captured by nucleus just before it stops. The production ratio of secondary nucleus from negative muon capture reaction on typical FPs are calculated using PHITS. The feasibility of nuclear transmutation by negative muon capture reaction for FPs is discussed

Model of negative muon capture reaction in PHITS

Simulation of nuclear transmutation for FPs

Findings

Conclusions