When the Fukushima nuclear power plant in Japan experienced a meltdown in 2011, a nuclear cloud was visited upon North America — and now that fissile material is evident in California wines bottled around the same time.
Is it possible to see the effects of the Fukushima nuclear disaster in California wines produced at the time?
Today we get an answer, thanks to a study carried out by Hubert and a couple of colleagues. “In January 2017, we came across a series of Californian wines (Cabernet Sauvignon) from vintage 2009 to 2012,” say Hubert and company.
Wine made prior to March 11, 2011 — the day of the meltdown — should show no sign of cesium-137, a telltale signature of nuclear disaster.
But wine made after that date would potentially show some sign of the radioactive material, which at high enough levels can be detected without disturbing the wine inside the bottle.
The team began their study with the conventional measurement of cesium-137 levels in the unopened bottles. That showed levels to be indistinguishable from background noise.
But the team was able to carry out more-sensitive tests by opening the wine and reducing it to ash by evaporation. This involves heating the wine to 100 degrees Celsius for one hour and then increasing the temperature to 500 degrees Celsius for eight hours. In this way, a standard 750-milliliter bottle of wine produces around four grams of ashes. The ashes were then placed in a gamma ray detector to look for signs of cesium-137.
Using this method, Hubert and his colleagues found measurable amounts of cesium-137 above background levels in the wine produced after 2011. “It seems there is an increase in activity in 2011 by a factor of two,” conclude the team.
Read more about the science of dating wine via cesium-137.