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.
When you get home from work, sometimes it’s nice to decompress for a few minutes before going in to start on chores/dinner/whatever. Especially if you have roommates or children that will immediately require your attention when you go inside.