The Chalk River nuclear reactor, which is capable of producing a third of the world’s medical isotopes, is back in service after a 15-month shutdown. Atomic Energy of Canada Ltd. (AECL), the Crown corporation that owns the 53-year-old reactor at Chalk River, Ont., announced last Tuesday (August 17) that the lengthy repairs required after a leak was discovered in May of last year have been completed. AECL did not say when clinics could expect to receive their first batch of the isotopes. The Conservative government of Prime Minister Stephen Harper has said it ultimately wants to get out of the medical isotope business and plans to shut down the reactor permanently in 2016.