Neutron Leakage From Polyethylene Slit

Abstract

A measurement of neutron dose rate on iron-polyethylene shielding structure was carried out by 252Cf source. Simulated geometry was slit-like opening of polyethylene in iron slab and polyethylene slab shielding. These experiment was done at research facility of Hazama Co,. Iron slab and polyethylene slab thickness were 10cm each. A gap of the polyethylene was simulated. Neutron REM-counter, polyethylene covered BF3 counter (STUDSVIK 2202-D), was used for measurement of streaming neutron dose equivalent. The solid state track detector (SSTD), allyl-diglycol-carbonate, were used for measurement of fast neutron dose equivalent in the range of l 70Kev to l 5Mev. The experimental data was obtained against gap width, source location and detector location. Obtained data shows strong correlation between dose rate and above parameters. These data was investigated in the view of to make use of actual facility design and compared with calculation such as MCNP48. From the result of gap streaming experiment and calculation, we obtained allowable gap width as 6mm for this case (10cm polyethylene thickness).