You might not notice the difference but if you’re on Ameren power, you’re not getting it from the Callaway Nuclear plant at this time. That’s because it’s undergoing its annual refueling and maintenance program that started this past Saturday. However, that’s not all that’s being done. For the first time since the plant went online in 1984, officials are replacing a reactor vessel, costing Ameren $150 Million. Officials are also replacing 84 of the 193 reactor core fuel assemblies which are 8 1/2inch square bundles of 12 foot long metal tubes that contain ceramic pellets of uranium dioxide fuel. They plan to turn the plant back on as soon as the work is completed. Power is currently being re-routed through Ameren’s other plants including Bagnell Dam.