The government has agreed to help Tepco compensate evacuees and other victims, conceding in the law that the state is partly responsible because it has promoted nuclear energy for decades.
A Tepco statement promised to move forward with "fair and prompt compensation" under the law and "with help from the government".
Tepco detected lethal hotspots at the plant this week, with radiation so high that it would kill a person within weeks if they were exposed to it for one hour.
Beef shipments were banned from four regions over the past fortnight after meat was found to be contaminated with caesium that rained onto the hay that the animals were fed.
The ban follows restrictions on some vegetables, dairy products, river fish, tea and other produce. Radiation has also been found in wheat, and the government is now testing rice fields in several prefectures.
Demand for farm and fisheries produce from the disaster-hit north-east has all but collapsed.
About 300 farmers demonstrated outside Tepco headquarters in Tokyo on Wednesday, some bringing dairy cows in trailers.