In the interests of bilateral ties, the United States in 1977 decided against telling Japan to refrain from operating a nuclear fuel reprocessing plant in Ibaraki Prefecture, according to declassified U.S. government documents.
Then President Jimmy Carter had previously advocated halting the launch of operations at the plant in Tokai, Ibaraki Prefecture.
But Mike Mansfield, who had just assumed the post of ambassador to Japan, convinced him to reverse this decision.
Mansfield told Carter that halting operations at the plant, operated by the now-defunct Power Reactor and Nuclear Fuel Development Corp., would have a detrimental impact on future Japan-U.S. relations, the documents indicate.