Tuesday, 11 September, 2007

R&D Info

The shutdown of the OPAL research reactor due to the problem of dislodged plates in the reactor's fuel assemblies is to continue longer than the predicted eight weeks.

The new reactor, which reached full power in November last year and was officially opened by the Prime Minister on April 20 this year, was shut down on July 27 as a result of problems identifed in its first eleven months of operation. These included seepage of light water from the reactor pool into the heavy water contained in the reflector vessel surrounding the core, and the dislodgement of fuel plates in each of the three fuel assemblies inserted into OPAL's core in the last monthly fuel change.

Analysis and testing of the fuel assembly fault has been undertaken by the fuel manufacturer in Argentina, and the results will determine the measures needed to fix the problems. Returning to power will then require approval by the independent safety regulator ARPANSA.

ANSTO's Chief of Operations, Dr Ron Cameron, said the detailed examination and removal of the fuel assemblies, including taking high resolution video footage of the fuel elements at the bottom of the 13 metre deep reactor pool, had been painstaking and had required progressive approval and consultation with ARPANSA.

"The responsibility for fixing the problem is with the reactor designer under the reactor warranty. " At this stage, ANSTO cannot give a firm time as to when the reactor will be back to full power and producing neutrons for research," he said.