Something in the Water: Fukushima Radiation in the Bering Sea

By: ​Mackenzie Bates

Summary: In March 2011, the Fukushima Daiichi nuclear power plant in Ōkuma, Japan suffered three meltdowns on par with Chernobyl after being rocked by a magnitude 9.0 earthquake and flooded by the subsequent tsunami, whose tallest wave reached 13-14 meters (43-46 feet) tall. Eight years later, scientists are finding remnants of the disaster as far north as the Bering Sea, near Alaska. Fortunately, the amount of contaminants such as the fission product cesium-137 found in the tested seawater are harmlessly low, recent tests show.

Both the incidents at Fukushima and at Chernobyl are the only catastrophes that have been rated a 7 on the International Nuclear Event Scale, the highest and most catastrophic rating. However, the Fukushima plant released just a fraction of the harmful radioactive isotopes that were released by Chernobyl twenty-five years earlier (10-20% as much), thanks in part to the concrete containment vessels used at the Fukushima plant.

Contaminated water from the Fukushima plant was released into the Pacific Ocean following the disaster, allowing around 18,000 terabecquerels of Cs-137 to enter the ocean initially. This Cs-137 has not significantly decayed (as it has a half-life of around thirty years), but it has since spread north from the site of the incident.

The waters of the Bering Sea, though, and the organisms living in them, are considered to be near-perfectly safe. For reference, drinking water with Cs-137 levels that are three thousand times as high as the amounts found in the Bering Sea would still be considered safe for humans to consume, according to the EPA. However, residents of the area want seawater testing to continue so that if any adverse effects of the radiation are discovered, they can be properly monitored.

Why we should care? This topic is important because we need to understand the drawbacks of nuclear power if we want to continue using it going forward. We especially need to be realistic about the effects it could have in the environment.

Credit: CC0 Public Domain

Example News Article: 
www.reuters.com/article/us-alaska-fukushima/fukushima-contaminants-found-as-far-north-as-alaskas-bering-strait-idUSKCN1R90BV

This article by Yereth Rosen is interesting because it phrases the results of this testing in a way that is pedestrian enough for everyone to understand, which is important for a topic like this that can directly affect ecosystems and everything (including people) that lives in them. People tend to panic at the mention of anything nuclear, so Rosen reiterates a few times in a few different ways that the radiation being seen in the Bering Sea in 2019 is not dangerous. It also often compares Fukushima to Chernobyl, which is a good frame of reference as far as disasters go, though Chernobyl had worse immediate and long-term effects due to the different structures of the two plants.

Science in Action.
Dr. Gay Sheffield  is a Sea Grant Marine Advisory Program agent and associate professor at the University of Alaska Fairbanks.

A study of the waters of the Bering Sea was conducted through Sea Grant Alaska and led by Gay Sheffield. The Woods Hole Oceanographic Institute tested the waters every year from 2014 to 2018 (except 2016) for levels of Cs-137 and Cs-134, finding that levels of Cs-137 had increased from 1.8 becquerels per cubic meter (Bq/m3) on April 2, 2017 to 2.4 Bq/m3 on August 3, 2018; meaning that levels of Cs-137 are now only slightly higher than they were before the incident. The tests for Cs-134 have found that in every year of the study, none was detected.

Sheffield spoke on the results of these tests to several news outlets, including Reuters above.
​
The information presented sets the tone for the discussion of the contamination of the Bering Sea and Bering Strait. Given that 7,400 Bq/m3 of Cs-137 is still considered safe for drinking water, 2.4 Bq/m3 utterly pales in comparison. The safety of these areas is not in peril from the Fukushima disaster, but residents of nearby areas are still concerned—as anyone would be if seawater contaminated by radiation lapped at their shores.