Handout photo from Tokyo Electric Power Co. shows worker attempting to repair power lines at the Fukushima Daiichi Nuclear Power Plant in Tomioka, Fukushima Prefecture northeastern Japan in this March 18, 2011 file photograph. Analysts suggest power blackouts will ultimately cause the biggest economic damage to Japan, a vital player in the global manufacturing supply chain.  The Tokyo area and regions further north make up half of the economic activity for the world's third-biggest economy, Nomura Holdings estimates. With Japan heading towards summer, when power demand tends to peak as air conditioners are used to combat rising temperatures, the power crunch could get worse. REUTERS