Today ANSTO was advised it now had the green light to re-start the OPAL research reactor following approval by the nuclear safety regulator ARPANSA of its application to modify the reactor fuel design and use the modified fuel to operate the reactor on 1 May 2008.
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| OPAL Control room. |
It is expected that the build up to full operation will take some weeks.
After nearly a year of successful operation, the OPAL reactor was shut down last July following the partial displacement of some fuel plates.
“Investigations into the cause of the displacements indicated that a combination of factors was involved, involving both fuel design and manufacturing processes. This necessitated a change to the fuel design to avoid future plate movements.
ANSTO’s Chief Executive Officer, Dr Ian Smith said he was happy the reactor could return to operation and that the process would commence immediately.
“It has been a frustrating time for all involved. However, it was important that these painstaking steps were taken to ensure that OPAL can recommence operating. We are keen to get back to business,” he said.
“We are hoping that full power of 20 Megawatts will be achieved in a few weeks’ time, but this has to be done gradually. It’s not just a case of flicking a switch.
“A special start-up core which consists of new fuel assemblies manufactured to the modified design and a neutron-emitting source are needed to begin the nuclear reaction, and the power is then gradually increased over a period of time,” he said.
The process of recovering from the fuel displacement took a number of months. Following the investigation, which began as soon as the problem was discovered, a solution to the problem had to be developed. This included design changes to the fuel assemblies and new ones being manufactured.
ANSTO lodged its application with ARPANSA in December 2007. Since then ANSTO has responded to questions and requests for clarification from ARPANSA as part of the assessment process.
During the whole process there was never any abnormal safety or radiation issues. The reactor design is sound and it operated successfully for a year prior to the shutdown.
ANSTO has continued to keep the community and customers regularly updated on progress during the shutdown.
Published: 05/05/2008