From the Asahi Shimbun:

Tokyo could be facing a power shortage this summer if most of the 17 reactors stay off-line. Tokyo Electric Power Co.'s last operating nuclear reactor will shut down today [April, 15], leaving all 17 of the firm's reactors - generating about 40 percent of the Tokyo metropolitan area's power requirements - off-line for safety inspections and repairs. A TEPCO source said if most of the reactors remain idle, Tokyo could see a severe power crunch, including the possibility of blackouts, this summer. The source said the company needs to get at least 10 of the reactors up and running before summer's peak demand for electricity. However, only one reactor is expected to resume operating soon.

Now this could get interesting....