Internet trolling pays off again. I think I've found some (semi real time) radiation data sites. My Japanese is limited to the auto translate function in Google Chrome but it appears there are some locations still publishing radiation data. I'm not quite certain of the units due to the translator but you can see peaks and valleys in the data and the peaks are not too much worse than the valleys. It also appears they liken 50,000 to a chest xray, or at least that's how Google Chrome is translating it....
Google map with locations (The locations near the plant are offline it appears)
Ibaraki Prefecture page (southwest of powerplants)