Commenter on this blog, Aldritch Parsons, suggested on March 30 some kind of tent of dome over the reactors to contain or limit the diffusion of radioactive materials. And today, I read on the Yomiuri (via the very useful NewsOnJapan.com):

The government will likely go ahead with a plan to spray resin inside the troubled Fukushima No. 1 nuclear power plant, which it hopes will contain the spread of radioactive substances, sources said Wednesday.

The government has begun full-fledged discussions on different plans to stop the spread of radioactive substances that have been leaking continuously from damaged reactors at the plant run by Tokyo Electric Power Co.

In addition to efforts to cool the reactors and spent nuclear fuel pools by TEPCO and the Self-Defense Forces, the government has asked for aid from private companies and other nations, including the United States, to deal with the accident.

It is believed spraying resin would minimize the spread of radioactive substances, which would allow repair work at the plant to proceed more smoothly, the sources said. Efforts to restore the reactors’ cooling functions have seesawed repeatedly, with the detection Wednesday of radioactive iodine-131 at levels 3,355 times the legal limit in seawater near the plant being the latest wrench in the works.

Spraying resin on debris inside the plant could begin as early as Thursday, the government sources said. The operation would last for about two weeks, they said.

The plan involves using a remote-controlled robot to spray resin over about 80,000 square meters inside the 120,000-square-meter facility. The areas to be sprayed were contaminated by radiation from debris scattered by several hydrogen gas explosions in the days after the March 11 earthquake.

via Govt may spray resin on N-plant / Sticky material should keep down radiation : National : DAILY YOMIURI ONLINE (The Daily Yomiuri).

And VOA’s Steve Herman, back in Seoul after 2 weeks covering the tsunami/earthquake/Fukushima disaster in Tohoku and Tokyo, tweets:

Officials: Unmanned, remote-controlled vehicle will spray the resin beginning Thursday “on a trial basis.”