U.S. Navy handout image shows Baker, the second of the two atomic bomb tests, in which a 63-kiloton warhead was exploded 90 feet under water as part of Operation Crossroads, conducted at Bikini Atoll

This U.S. Navy handout image shows Baker, the second of the two atomic bomb tests, in which a 63-kiloton warhead was exploded 90 feet under water as part of Operation Crossroads, conducted at Bikini Atoll in July 1946 to measure nuclear weapon effects on warships. The United States said on April 25, 2014, it was examining lawsuits filed by the Marshall Islands against it and eight other nuclear-armed countries that accuse them of failing in their obligation to negotiate nuclear disarmament. REUTERS/U.S. Navy/Handout via Reuters (MARSHALL ISLANDS - Tags: POLITICS MILITARY CONFLICT) ATTENTION EDITORS - FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS. THIS PICTURE WAS PROVIDED BY A THIRD PARTY. REUTERS IS UNABLE TO INDEPENDENTLY VERIFY THE AUTHENTICITY, CONTENT, LOCATION OR DATE OF THIS IMAGE. THIS PICTURE IS DISTRIBUTED EXACTLY AS RECEIVED BY REUTERS, AS A SERVICE TO CLIENTS - GM1EA4Q0L6601