Japan atom plant main vessel may be damaged-IAEA

VIENNA, March 15 (Reuters) - An explosion on Monday at Japan's disaster-hit nuclear plant may have damaged the primary containment vessel of one reactor unit, the Vienna-based U.N. nuclear watchdog said.

The International Atomic Energy Agency said the explosion at the Fukushima Daiichi unit 2 "may have affected the integrity of its primary containment vessel."

The IAEA said primary containment vessels of units 1 and 3 appeared intact despite explosions there. It said units at the Fukushima Daini, Onagawa, and Tokai nuclear power plants were in a safe and stable condition. (Reporting by Sylvia Westall and Fredrik Dahl; editing by Mark Heinrich)