Abstract: Piping of a nuclear reactor containment vessel comprises pipes passing through the containment vessel and, extending to the outside of the containment vessel, outer shut-off valves each provided at a portion of the pipe which is located at the outside of the containment vessel for closing the pipe and isolating vessels for covering at least outer surfaces of welded portions of the pipes each being located between an outer wall surface of the containment vessel and a portion including the outer shut-off valve and for isolating the covered portions of the pipes from atmosphere.

Abstract: Addition of a specified alkanol amine and a polybutadiene having terminal maleic anhydride groups to a conventional nitramine composite propellant which contains a nitramine oxidizer in a high content improves the resulting uncured propellant slurry in fluidity and the cured propellants are excellent in mechanical and burning properties.

Abstract: A rotor for a rotary electrical machine having a superconductive field winding, wherein thermal resistance means is arranged at contact parts between a damper, which is so disposed as to cover the superconductive field winding, and a damper support which supports the damper from the inner side thereof. A plurality of protuberances are formed on either said damper support or said damper for restricting heat flow between said damper and said damper support. It is possible to cause a cooling medium to flow through interstices which are defined at the contact parts between the damper and the damper support.