French submarines are a bit different from, say, US or British ones. They are refueled at 10 year intervals, and designed accordingly (e.g. there's a big hatch

French submarines are a bit different from, say, US or British ones. They are refueled at 10 year intervals, and designed accordingly (e.g. there's a big hatch above the reactor which can be removed for the refueling), and they use LEU fuel produced in an enrichment facility that also produces civilian nuclear fuel.