Outline of radiation shielding (streaming) code system used in Kawasaki Heavy Industries, Ltd. (KHI)

The most troublesome problem in designing nuclear reactor shielding is streaming. The paper introduces the shield computing code system of Kawasaki Heavy Industries, Ltd. (KHI) centering around the streaming. This code system is roughly composed of 9 sections, each of which is explained. Of these, the transmission computing section and the streaming computing section have no significant difference as both handle radiation transport problems. These computing code groups are divided into the one used for neutrons only, the one for gamma emission only and the one for both neutrons and gamma radiation. In the second half of the paper, the codes RASC2D and DOT3.5 are specifically described in detail, which are frequently used in KHI as the codes for streaming analysis. The RASC2D has been developed by KHI, started in 1970 in commission of the Power Reactor and Nuclear Fuel Development Corporation. The DOT code was developed in ORNL, U.S., and the present DOT3.5 is the latest one of the DOT codes usable in Japan. The code DOT3.5 is more convenient to use than the RASC2D if both are compared, and thus KHI employs DOT3.5 more frequently than RASC2D at present. (Wakatsuki, Y.)