After being shut for about seven months for annual maintenance, Unit-I of Koodankulam Nuclear Power Plant (KKNPP) attained criticality on Thursday evening. The plant was shut down for maintenance for two months, but fuel could be reloaded only last month.
Officials from the power plant in Tirunelveli said the 1,000 MW Unit-I attained criticality — beginning of the chain reaction — at 4.19 pm. After the second phase of fuel cycle operation was put into service and systems were normalised, the steam relief devices testing started on January 17. Following that, the nuclear fission process started.
The process started at 11.49 pm on Wednesday, and the reactor power will be increased gradually to attain the production of 1,000 MW as per procedures and regulatory clearance. The entire process is being supervised by the Atomic Energy Regulatory Board (AERB), Nuclear Power Corporation of India Ltd (NPCIL) and Russian specialists, according to H N Sahu, station director, KKNPP.
Once the reactor attains criticality, the power production is expected to resume within a week, said another top official from the plant. The unit would reach its maximum output of 1,000 MW gradually, the official added.
Unit-I was shut on June 24, 2015 for annual maintenance, but fuel could be reloaded only in December.