SEALING DEVICE BETWEEN UPPER SHIELD BODY AND CONTROL-ROD-GUIDE TUBE OF HIGH TEMPERATURE GAS REACTOR

摘要

PROBLEM TO BE SOLVED: To attain distribution of helium flow in planned quantity to control rod insertion hole even if there exists a shift in the axes between control rod guide tube and the control rod insertion hole in an upper shield body. SOLUTION: A sealing device consisting of a flange 10a attached to the lower part of a control rod guide tube 6, a seal ring 10 which has a cylinder part 10b with an inner diameter nearly equal to that of the control rod guide tube 6 and a plurality of screws 11 fixed between the lower part of the flange 10a and the upper part of an upper shield body 7, is placed. When a gap is generated between the control rod guide tube 6 and the upper shield body 7, the flange 10a is allowed to displace keeping contact with the control rod guide tube 6, and so helium flow rate to the control rod insertion hole 7a can be regulated.