The problems at the plant are:
1. There is no electric power to do anything.
2. The stored fuel rod pools are the main problem. They are located above the reactors in the same buildings and they cannot keep the spent fuel rods covered. They appear to be the radioactive source, not the reactors. They have no way to pump water (seawater - the only source now) up to them without power. They were using firetrucks, but they have been damaged in the hydrogen explosions.
3. There are 6 reactors, all with the same pools and problems. Every time one gets under control, another loses water and it's like juggling 6 hot potatoes.
The radiation from the rods doesn't contain I-131 (Iodine-131), so I-127 (Iodine-127) has no effect. It's meaningless.
The radiation levels outside the immediate area of the plant is in the scale of 0.8 µSv. That is 8/10,000,000th of a Sv. It has no effect on anything.
Japan has bigger problems than that. The trucks aren't running, the grocery stores throughout the entire Tokyo (200 miles and 40 million people south) are running out of food, there is no gasoline (we don't know why) and stores are only open for a few hours because of rolling blackouts from power shortages. Some areas only have 3-4 hours of power per day. Factories and other businesses are all closed.