A surface soil sample was personally taken from the edge of the hard standing in the car park by a church in Aizu Wakamatsu in July 2011. Aizu Wakamatsu is approximately 100km west of the Fukushima Daiichi plant.
The Uranium-238 daughter Thorium-234 and Uranium-235 daughter, Thorium-231 were measured in this sample, which means Uranium-235 and -238 were here as well.
Uranium-235 is, of course, a decay product of Plutonium-239 which was a component of the MOX fuel in Fukushima Reactor 3. Plutonium-239 cannot be detected by gamma spectrometry. Although caution should be exercised in drawing this conclusion on the basis of the exact ratio since the peaks are weak, it would suggest there is far too much enriched Uranium here, which is of concern. A sample will be sent for Mass spectrometry
(ICPMS) to follow this up.
The total Uranium concentration is also quite high at 112 Bq/kg (expected is about 10 to 20 Bq/kg). The matter of the Uranium contamination requires more research.