With a contract signed in 1991, AECL, in partnership with MDS Nordion, began construction of the MAPLE dedicated isotope-production facility. Constructed on-site at AECL's Chalk River Laboratories this facility would house two reactors and an isotope processing facility. Each reactor was designed to be able to produce at least 100% of the world's medical isotopes, meaning that the second reactor would be used as a back-up to ensure an uninterruptible supply. The first reactor was started but experienced malfunctions in its safety rods, and a positive nuclear power feedback coefficient was recorded. After running over the Schedule by more than 8 years and more than doubling the initial budget,