"Sophisticated diagnostic procedures are required to determine the exact nature and extent of the repairs before returning the NRU reactor safely to service," Bill Pilkington, chief nuclear officer at AECL, said in a statement. "Based on our preliminary findings to date, we now believe that the NRU reactor will be out of service for at least three months."
Natural Resources Minister Lisa Raitt said she is still talking to other countries that produce medical isotopes to figure out how to fill the gap in supply.
"I continue to lead productive discussions with my counterparts in other isotope-producing countries that have some ability to assist with this supply issue," Raitt said in a statement. "These countries all have different constraints and capacity that we are working through, but we will continue using all resources available to us to manage this shortfall."
Federal Health Minister Leona Aglukkaq said she is working with her provincial and territorial counterparts to see how hospitals can best cope with the shortage of the radioisotopes needed for crucial diagnostic tests. Isotopes are used in some cancer treatments.
"The real problem is that those other reactors don't have the excess capacity that (Chalk River) has," said Robert Atcher, president of the Society of Nuclear Medicine.
Atcher told Reuters there are also fears AECL will find other corrosion problems in the reactor that will lengthen the shutdown or force a permanent closure.
"To say we're concerned is an understatement," Atcher said.
Hugh MacDiarmid, AECL's chief executive, said: "Until all investigations are completed, it is premature at this point to set a definitive timeline for the return to service of the NRU reactor."