Shielding experiment for the First Nuclear Ship in Japan

Abstract

The experimental investigations on the marine reactor shielding in Japan were initiated in 1957 as well as theoretical studies. Among others, a series of extensive shield mockup experiments were performed through 1965 to 1967 in connection with the final design of the First Nuclear Ship in Japan. These include mockups of the primary shielding both in the core radial direction and in obliquely upwards direction, secondary shield samples with cylindrical penetrations and samples having gaps between shield blocks. In this paper, after a brief historical survey of relevant works, the mockup experiments for the side primary shield, the instrumentation tubes arranged in the reactor shield tank, and gaps of thin rectangular slit formed between lead slabs, concrete blocks or both are described. The results thus obtained have established the applicability of design procedures to the shield configuration which is to be used in the actual shield under construction.