What’s the dose up there?

The best thing with plane trips is that they’re a great way to test your Geiger counter. If you don’t have one you can also look out the window or catch up with your crappy movies stack but you’re then missing out on all the fun.

Typical dose rate on a plane: 3.4 µSv/h

At an altitude of 10 000 m the typical dose rate is indeed around 3 µSv/h instead of the 0.1 µSv/h that is commonly observed at ground level. The culprit is of course the atmosphere layer that gets thinner as the plane flies higher and can thus absorb less cosmic radiation.

That is not a problem for passengers who are flying only occasionally but for pilots and cabin crews the dose may be more than negligible. Since 1996 EU legislation thus requires airline companies to monitor their employees’ exposure. In the industry or medical field this is usually done through dosimeters but for a reason that will be explained later it would be far too impractical here. The chosen solution is thus different: all flights performed by pilots or cabin attendants are registered in an online database from which the received doses can be computed thanks to a model that is updated periodically with data provided by the IRSN (Institut de Radioprotection et de Sûreté Nucléaire) and Observatoire de Paris.


A die-hard cask

Some months ago a spent nuclear fuel transport coming from the Netherlands and going to La Hague passed nearby Paris. According to lots of very vocal people it was supposed to be an evil train from hell wreaking havoc wherever it went, spewing giant fireballs of doom. I got rather curious at the prospect of witnessing such an abomination for real so I eagerly went to wait on the platform of a RER station the train was supposed to drive through, expecting to see something along these lines:

Motörhead train (Joe Petagno)

Instead I got something like that:

CASTOR train sitting in the Bourget station (Suaudeau, 2013)


A striking coincidence

The China Syndrome (Columbia Pictures)

March 16 1979: “The China Syndrome” came out in theaters all over US. The movie revolves around a small team of journalists that happen to witness an accident while doing a report on a nuclear power plant. Although determined to get the word out with the help of the Shift Supervisor they soon meet strong resistance from the plant management who are trying to cover up the full extent of the event. It is mainly through this movie that many heard for the first time about the “China Syndrome”, a nuclear accident concept involving a total melting of the core followed by a fictitious trip through the Earth’s crust all the way down to the antipodes.1

March 28 1979 (less than 2 weeks afterward): Unit 2 in Three Mile Island Nuclear Power Plant, Pennsylvania, went through a serious accident that was completely tackled only a week later. The health and environmental effects were fortunately very limited if not non-existent, even though after opening the reactor vessel many years later it was discovered that the core had partially melted.


  1. Interestingly enough if we exclude Hawaii and Alaska US antipodes are actually not located in China but right in the middle of the Indian Ocean. The only dry land in this area is the French Southern and Antarctic Land (Kerguelen, Amsterdam and St. Paul islands). []

Smoke on the water

On September 5 2012 some smoke could be seen rising fom the Fessenheim Nuclear Power Plant in France. Obviously this drew a sizeable swarm of journalists, all waiting for a disaster to strike. When it became finally clear that nothing big was going to happen everybody went home and carried on with the next slightly significant piece of news. But what was this fuss all about anyway?