OPAL News
Since the last Bragg Peaks in October 2008, OPAL and its cold-neutron source have continued to run well, with an availability of 80% in the last cycle (compared with ~60% for the previous cycles). We continue to have some minor teething problems, for instance failures of neutron-flux detectors in the reactor itself, loss of offsite power (due to electrical storms) and opening of primary shutters.
The main reactor issue now affecting our users is that we have a somewhat inflexible protocol for moving fuel within the reactor core, that these fuel movements drive the reactor schedule in the event of unforeseen shutdowns, and in consequence we have difficulty sticking to a predetermined calendar schedule. We are currently working with our regulator ARPANSA to obtain approval for a modified fuel-management strategy, which will then allow us to stick to a fixed reactor schedule.
The current reactor cycle (number 12) started on 26 January 2009 with the next shutdown scheduled for 22 February 2009. This shutdown will be three weeks in order to look into the previously reported reflector-vessel defects. After the restart in mid-March the preliminary reactor operation schedule goes up to cycle 16 with the following reactor start-up and shutdown dates: 12 March – 6 April, 11 April – 13 May, 23 May – 17 June, and 22 June – 24 July 2009.