COMPREHENSIVE IN-SERVICE INSPECTION OF KARTINI REACTOR TANK LINER AND FITNESS FOR CONTINUED OPERATION

摘要

The preliminary comprehensive in-service inspection of the Kartini reactor core and tank liner by using non-destructive testing (NDT) methods to maintain its safe operation, have been done. The type of NDT used were visual examination using underwater camera and magnifier, replication survey using dental putty, hardness test using an Equotip-D indentor, thickness test using ultrasonic probe, and dye penetrant test. The visual examination showed that the surface of the reactor tank liner was in good condition. The hardness readings were considered to be consistent with the original condition of the tank. The slight increase in hardness at the reactor core area, and this is consistent with the neutron fluence experienced, i.e. ～10~(15) n/cm~2, where high fluence will cause higher increased hardness of the material. Results of an ultrasonic thickness survey showed that, on average, the tank thickness is between 5.0 mm and 6.5 mm, a low 2.1 mm thickness exists at the top of the tank liner in the belt area. But, because the area is a double layer aluminium plat, its decrement in thickness does not influence the reactor safety. The replica and dye penetrant test at the low thickness area and several suspected areas showed that there could be some defect from the original manufacture. Therefore, it can be concluded that the reactor tank liner is still feasible for continued safe operation.