Analysis of neutron attenuation in boron-alloyed stainless steel with neutron radiography and JEN-3 gauge

This paper concerns the neutron attenuation behavior of boron-alloyed stainless steels, and quantitative estimations of secondary effects on the neutron transmission measurements, such as beam hardening, background and micro-structure of neutron absorber causing a decrease in the total macroscopic cross-sections. Systematic thermal neutron transmission measurements of boron-alloyed steel plates have been performed at different neutron radiography facilities and at a portable gauge called JEN-3, which is a practical neutron transmission setup for industrial demands in non-destructive material inspection. In addition, MCNP (Monte Carlo Neutron Particle transport) simulations were performed for a better understanding of the experimental results, the secondary factors affecting the total macroscopic cross-sections, and the characteristics of the JEN-3 gauge. The detectable thickness limit for 1.88 wt% natural boron-alloyed steel plates was determined as 1-1.5 cm depending on the contributions of the secondary factors in each facility.