SARS-CoV-2 Inactivation Simulation Using 14 MeV Neutron Irradiation.

Fang Liu,Xin Yuan,Zhengtong Zhong,Tianze Jiang,Xiaoping Ouyang,Hongchi Zhou,Fenglei Niu,Guanda Li,Peiguang Yan,Bin Liu

doi:10.3390/life11121372

Abstract

The SARS-CoV-2 virus is deadly, contagious, can cause COVID-19 disease, and endangers public health and safety. The development of SARS-CoV-2 inactivation technology is crucial and imminent in current pandemic period. Neutron radiation is usually used to sterilize viruses because neutron radiation is 10 times more effective than gamma-rays in inactivating viruses. In this work we established a closed SARS-CoV-2 inactivation container model by the Monte Carlo method and simulated the inactivation performance by using several different neutrons sources. To study the effects of inactivation container factors, including the reflector thickness, the type of the reflector material, the SARS-CoV-2 layer area and the distance from the radiation source on the energy deposition of a single neutron particle in SARS-CoV-2 sample, we simulated the neutron energy deposition on a SARS-CoV-2 sample. The simulation results indicate that the saturated thicknesses of reflector materials for graphite, water and paraffin are approximately 30 cm, 15 cm, and 10 cm, respectively, and the energy deposition (radiation dose) becomes larger when the SARS-CoV-2 layer area is smaller and the SARS-CoV-2 layer is placed closer to the neutron source. The calculated single-neutron energy deposition on 10 × 10 cm2 SARS-CoV-2 layer is about 3.0059 × 10−4 MeV/g with graphite as the reflection layer, when the 14 MeV neutron source intensity is 1012 n/s and the SARS-CoV-2 layer is 5 cm away from the neutron source. If the lethal dose of SARS-CoV-2 is assumed as the IAEA recommended reference dose, 25 kGy, the SARS-CoV-2 could be decontaminated in about 87 min, and the sterilization time could be less than 52 s if the 14 MeV neutron intensity is increased to 1014 n/s.

Highlights

Neutrons and hydrogen atoms have high nuclear interaction cross sections, which indicates the possibility of interaction between neutrons and hydrogen atoms is high and neutrons can cause damage to SARS-CoV-2 DNA strands
We can see that the single-neutron energy deposition increases rapidly when the reflector thickness is less than 10 cm for the three materials used
We suggest that medical products contaminated by SARS-CoV-2 should be placed around the neutron source in a circle to improve the sterilization efficiency

Summary

Introduction

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) [1] is currently sweeping round the world and has caused the coronavirus disease 2019 (COVID-19). Pneumonia (shown in Figure 1 [1]). This is a new strain of coronavirus, which is contagious, can spread rapidly and widely through carriers, and has threatened human lives globally. The coronavirus was discovered in the 1930s [2], coronaviruses gained worldwide attention when the severe acute respiratory syndrome outbreak shook the world in 2003. Biologists’ interest in this family of viruses grew in the aftermath of the epidemic of 2003, leading to the identification of many new coronavirus family members. The coronavirus break out in 2003 gave a hint of the ability of coronaviruses to jump

Methods

Results

Conclusion