Marcoule's long nuclear history
The Marcoule site is one of the oldest in France, and played a significant role in the development of the French nuclear and thermonuclear deterrents.
It opened in 1956 - well after the US began the era of nuclear armaments, at a time when France was among the nations looking to gain their own seat at the nuclear table.
The earliest reactors generated first data and then plutonium for the first successful French test in 1960.
Other defence-oriented reactors followed - and as the world contemplated a new generation of much bigger bombs with much bigger destructive capacity, a new reactor at Marcoule was built to produce tritium, fuel for hydrogen (or thermonuclear) weapons.
On the civilian side, the site also housed the experimental Phenix fast-breeeder reactor, and - since 1995 - it has combined fissile uranium and plutonium into mixed oxide (MOX) fuel, which can be used in nuclear power stations.
However, like other sites such as the UK's Sellafield that date from the dawn of the nuclear age, Marcoule's principal activity these days is cleaning itself up.
In the 1950s and into the 60s, the priority was to get the job done - to meet the military imperative of fuel production, to irradiate whatever needed irradiating, without much of a thought about how the facilities would eventually be rendered safe.
Marcoule is now dealing with the legacy of radioactive waste that created.
Reports in French media suggest the latest incident occurred in a facility storing waste, with a fire and an explosion killing one person and injuring a further four.
So far, authorities are saying there has been no release of radioactive material.
The French nuclear programme does not have a stellar record of transparency.
In environmental circles, particular opprobrium is reserved for officials who in 1986 claimed the Chernobyl accident would have no impact on France - a statement lampooned as indicating officials believed radioactive fallout observed national boundaries.
What the incident implies for the future of the French nuclear programme is not entirely clear.
If it remains a relatively minor matter, it will probably be passed off as the type of thing that regrettably happens in all types of industrial facility.
However, Marcoule is on the list of candidate sites to host one of the European Pressurised Water Reactors (EPRs) that according to government policy are to provide the next generation of French citizens with nuclear electricity.