There are several factors to consider when choosing materials in a nuclear plant. For things that aren’t in direct proximity to the reactor core, neutron activation (becoming radioactive) is less of a concern. Aluminum produces hydrogen gas when exposed to boric acid, which presents an explosion risk. Certain chemical compounds can cause corrosion to plant equipment, even a Sharpie marker could corrode a valve or pipe and cause issues over the 50 year life span of a plant.
If he gets assassinated, they may replace him with a somewhat competent candidate. I think he stands a pretty good chance of losing, let’s keep him in the race until November.