REACTOR STRUCTURE WITH ROTATABLE REACTOR CORE TANK

PROBLEM TO BE SOLVED: To reduce the diameter of a reactor vessel and to simplify reactor structure by suspending a reactor core tank for accommodating a reactor core from a fixed shielding plug rotatably. SOLUTION: The reactor core 1 is suspended from a fixed-type reactor core upper lid 2 and is accommodated in the reactor core tank 3. The reactor core 1 is suspended from the upper lid 2 via a bearing 4, and the reactor core tank 3 is rotatable with the bearing 4. A coolant flows inside from inlet piping 5 being provided at four locations around a reactor vessel 6, flows down a channel being sandwiched by the reactor vessel 6 and an outer cylinder 7 that is suspended from the reactor core upper lid 2, flows into a lower plenum 8, and then flows into the reactor core 1. The coolant that reaches high temperature by cooling the reactor core 1 flows into an upper plenum 9 and flows out of outlet piping 10 being provided at four locations around the upper plenum 9. The shielding plug of the outlet piping 10 does not rotate, and the outlet piping 10 has a delivery port at the upper portion of the bearing 4 and is not affected by the influence of the rotation of the reactor core tank 3, so that it can bed installed at the upper portion of the reactor core.