Welding repairs to the world's main medical isotope production reactor are now complete. Public hearings on its restart are imminent as it is prepared for service.


Engineers study the inside of NRU on
screen (Image: AECL)

The National Research Universal (NRU) facility at Chalk River in Canada has been out of operation since mid 2009 when it became known that corrosion in its tank structure had led to a water leak. In that time supplies of the isotopes for cancer therapy and medical imaging have been tight across the world.


Owner and operator Atomic Energy of Canada (AECL) had to drain the reactor tank, remove the fuel, remotely examine the inside of the tank, develop a long-range repair tool and train engineers to carry out the welding job. After several weeks of welding that principal task has been completed and verified, the company said, and it is possible to resume safe routine operation.


The Canadian Nuclear Safety Commission (CNSC) has scheduled the required public hearing on the restart of NRU for 28 June. The usual rules for this kind of hearing have been amended to "significantly compress the notification period and time usually allocated for the submission of documents by the licensee [AECL], the public and CNSC staff." This should ensure "AECL's request can be dealt with in a fair an expeditious manner," said the regulator before inviting the public to submit their views.


The repair team is now to vacuum the reactor tank for handover to a restart team which is concentrating on "the synchronised execution of the 3000+ activities that must be completed prior to returning NRU to service." The largest task is the reloading of fuel, which must be carried out in accordance with a protocol of checks previously agreed with the CNSC.


The NRU is currently expected to return to service by the end of July, AECL said, with the first medical isotopes removed for processing and distribution about ten days later.


Researched and written

by World Nuclear News


Date: Friday, 18 June 2010
Original article: world-nuclear-news.org/Articles/Preparations-for-restart-of-isotope-producer