The horror meltdown in 2011 was sparked by a massive tsunami, causing waves that overwhelmed the plant's reactors.
But despite fears about radioactive particles possibly entering the food and drink chain, the World Health Organisation insisted the risk outside Japan was relatively low.
But it can now be revealed that wine made in the west coast US state since the meltdown contain isotopes from the accident's fallout.
Researchers at the French National Center for Scientific Research (CNRS) reported the worrying find this week.
Scientists said samples of red and rosé contained quantities of Caesium-137.
The radioactive material will most likely be present as it was carried in clouds to the United States, which then entered the water system through rain.
But experts said that in such small doses, it does not pose a risk to health, adding its level of radioactivity is actually lower than natural radiation.
Areas of Fukushima are still strictly off limits to humans due to toxic levels of radiation.
Last year, terrifying pictures emerged of raging packs of contaminated wild boars that live in the exclusion zone.
Poachers were drafted in to slaughter the terrifying creatures after they started roaming around surrounding towns.
Comment: If those are the levels found in California then what are the levels like in the still habited areas surrounding Fukushima? And the idea that it's of no risk to human life is most likely untrue. It's also worth bearing in mind Fukushima isn't the only source of radiation on our planet, as noted in High altitude nuclear weapons testing impacted space weather: See also: