By Jacob M. Schlesinger and Toko Sekiguchi

In the midst of the solemn, scripted memorial marking the anniversary of Japan's 2011 triple disaster, a discordant note seemed to creep in.

A leading lawmaker used the bully pulpit at the ceremony to call for an end to nuclear power, a rare instance of apparent public dissent by a top ruling party official against the policy of Prime Minister Shinzo Abe.

"It seems as if we have reaped the benefits of electricity...while letting the people of Fukushima bear the cost," said Bunmei Ibuki, the speaker of Japan's lower house of parliament. Mr. Ibuki made his remarks at the National Theater during Tuesday's memorial to mark the third year since a giant earthquake off the country's northeast coast triggered a mammoth tsunami that killed nearly 16,000 people, left over 2,500 missing and caused one of the world's worst nuclear disasters.