By: History.com Editors

1981

Japanese power plant leaks radioactive waste

Published: November 13, 2009

Last Updated: January 30, 2025

A nuclear accident at a Japan Atomic Power Company plant in Tsuruga, Japan, exposes 59 workers to radiation on March 8, 1981. The officials in charge failed to timely inform the public and nearby residents, endangering them.

Tsuruga lies near Wakasa Bay on the west coast of Japan. Approximately 60,000 people lived in the area surrounding the atomic power plant. On March 9, a worker forgot to shut a critical valve, causing a radioactive sludge tank to overflow. Fifty-six workers were sent in to mop up the radioactive sludge before the leak could escape the disposal building, but the plan was not successful and 16 tons of waste spilled into Wakasa Bay.

Despite the obvious risk to people eating contaminated fish caught in the bay, Japan’s Atomic Power Commission made no public mention of the accident or spill. The public was told nothing of the accident until more than a month later, when a newspaper caught wind of and reported the story. By then, seaweed in the area was found to have radioactive levels 10 times greater than normal. Cobalt-60 levels were 5,000 times higher than previous highs recorded in the area.

Finally, on April 21, the Atomic Power Commission publicly admitted the nuclear accident but denied that anyone had been exposed to dangerous levels of radiation. Two days later, the company running the plant declared that they had not announced the accident right away because of Japanese emotionalism toward anything nuclear. The public also learned for the first time that, in an earlier incident at the same plant in January 1981, 45 workers had been exposed to radiation.

All the fish caught in Wakasa Bay following the accident were recalled and reports indicate that fish in the area displayed far more mutations than normal for several years after the incident. In May 1981, the president and chairman of the Japan Atomic Power Company resigned.

Timeline

Also on This Day in History

Discover more of the major events, famous births, notable deaths and everything else history-making that happened on March 8th

About the author

HISTORY.com works with a wide range of writers and editors to create accurate and informative content. All articles are regularly reviewed and updated by the HISTORY.com team. Articles with the “HISTORY.com Editors” byline have been written or edited by the HISTORY.com editors, including Amanda Onion, Missy Sullivan, Matt Mullen and Christian Zapata.

Fact Check

We strive for accuracy and fairness. But if you see something that doesn't look right, click here to contact us! HISTORY reviews and updates its content regularly to ensure it is complete and accurate.

Citation Information

Article title
Japanese power plant leaks radioactive waste
Website Name
History
Date Accessed
March 25, 2025
Publisher
A&E Television Networks
Last Updated
January 30, 2025
Original Published Date
November 13, 2009

History Every Day

Sign Up for "This Day in History"

Uncover fascinating moments from the past every day! Learn something new with key events in history, from the American Revolution to pop culture, crime and more.

By submitting your information, you agree to receive emails from HISTORY and A+E Global Media. You can opt out at any time. You must be 16 years or older and a resident of the United States.