Pebble bed reactors, friction, and cooling

May 25, 2021, 9:31AMANS Nuclear CafeLaura Simmons

When one of the largest modern earthquakes struck Japan on March 11, 2011, the nuclear reactors at the Fukushima Daiichi nuclear power plant automatically shut down as designed. The emergency systems, which would have helped maintain the necessary cooling of the core, were destroyed by the subsequent tsunami. Because the reactor could no longer cool itself, the core overheated, resulting in a severe nuclear meltdown.

Since then, reactors have improved exponentially in terms of safety, sustainability and efficiency. Unlike the light-water reactors at Fukushima, which had liquid coolant and uranium fuel, advanced reactors have a variety of coolant options, including molten-salt mixtures, supercritical water, and gases such as helium.

IEA: CO2 emissions on their way back up

April 27, 2021, 9:32AMNuclear News

The decline in global carbon dioxide emissions recorded last year will not continue through 2021, a new report from the International Energy Agency concludes. Released last week, Global Energy Review 2021 finds that energy–related CO2 emissions are on course for the second-largest increase in history, reversing most of 2020’s COVID pandemic–related drop. The surge would be the largest since 2010, during the carbon-intensive recovery from the worldwide financial crisis, according to the agency.

Adding context to Japan’s (correct) decision to dispose of Fukushima wastewater

April 13, 2021, 6:28AMNuclear News
A current picture of the Fukushima nuclear power station with the more than 1,000 water storage tanks on site. Photo: Courtesy of TEPCO.

The Japanese government will soon announce the decision to dispose of stockpiled Fukushima wastewater into the Pacific Ocean, according to an AP News story published last Friday. The decision is years in the making and follows the guidelines from a panel of government-appointed experts named the Subcommittee on Handling of the ALPS-Treated Water (ALPS Subcommittee).

Advanced liquid waste processing systems: Safely processing Fukushima’s wastewater

March 19, 2021, 2:07PMNuclear NewsJohn Fabian

The Tokyo Electric Power Company (TEPCO) became a household name a decade ago as the operator of the Fukushima Daiichi nuclear power plant, center of the largest nuclear accident in a generation. Now in 2021, as a result of the continuous mitigation efforts, TEPCO is currently storing 1.2 million cubic meters of treated wastewater—and counting—in more than 1,000 large storage tanks on site. This wastewater has been in the spotlight for the past few years since current projections show that storage capacity will run out by 2022. That spotlight intensified last year when a panel of experts from Japan named the Subcommittee on Handling of the ALPS-Treated Water (ALPS Subcommittee) recommended to the Japanese government that the treated wastewater should be released into the ocean. The ALPS Subcommittee’s report states, “The topic of how to handle the treated water is one of the most important decommissioning tasks, which has been discussed since 2013.” This issue has plagued the decommissioning and decontamination efforts for the past decade for one simple reason: a failure to effectively communicate about the low risk involved with processing, diluting, and discharging the water over a period of several years.

Critical Look: PBS Newshour’s coverage of 10th anniversary of the Fukushima nuclear accident

March 15, 2021, 3:00PMNuclear News

Along with many other media outlets on March 11, the PBS NewsHour reported on the continuing recovery efforts from the earthquake and tsunami that devastated northeastern Japan 10 years ago. The segment, "Japan marks 10th anniversary of Fukushima nuclear disaster," is just over eight minutes long, most of which discusses the effects of the earthquake and tsunami on the region and Japan’s preparedness for the next major natural incident.

Germany settles with utilities over nuclear phaseout

March 15, 2021, 7:00AMNuclear News

RWE’s Gundremmingen nuclear plant, located in Bavaria, is slated to close at the end of the year. Photo: Wikipedia/Felix König

After years of litigation, Germany has reached an agreement with four utility companies on compensation for losses incurred as a result of the government’s stunning decision in 2011 to abandon nuclear power. In March of that year, only days after the Fukushima Daiichi disaster, German Chancellor Angela Merkel announced a 180-degree reversal in the country’s energy policy, which had been one of support for nuclear power. Eight units were shut down immediately, and by May 2011 the government had announced a plan to close all nuclear power plants by 2022.

The companies will receive a total of €2.4 billion (about $2.85 billion), with €1.4 billion going to Sweden-based Vattenfall and the remaining €1 billion split between German utilities RWE (€880 million), EnBW (€80 million), and E.ON (€42.5 million). In return, the companies have agreed to terminate all phaseout-related legal disputes with the government.

Safely decommissioning Fukushima Daiichi and revitalizing Fukushima

March 11, 2021, 12:00PMNuclear NewsAkira Ono

Akira Ono is chief decommissioning officer of Tokyo Electric Power Company Holdings and president of the Fukushima Daiichi Decontamination and Decommissioning Engineering Company.

The mission of Tokyo Electric Power Company Holdings (TEPCO), and my personal mission, is to safely decommission the damaged Fukushima Daiichi nuclear power station and thereby contribute to the revitalization of Fukushima.

In performing this important work, we are guided by the principle of balancing the recovery of Fukushima with the decommissioning of the Fukushima Daiichi nuclear power station, doing everything possible to mitigate the risks as we progress. Since the accident on March 11, 2011, we have stabilized the site and alleviated many of its crisis aspects.

Most significantly, we have been making efforts to improve the working environment by reducing the contamination on the site due to the accident. About 4,000 workers are currently engaged at Fukushima Daiichi. The average monthly radiation dose for those workers has been reduced from 21.55 mSv (2,155 mrem) immediately following the accident to 0.3 mSv (30 mrem).

Statement on the 10th anniversary of Fukushima

March 11, 2021, 9:27AMPress Releases

This week marks the tenth anniversary of the earthquake and tsunami that killed approximately 19,000 people in Japan and subsequently triggered the Fukushima Daiichi accident. The International Atomic Energy Agency rated Fukushima as a level 7 major accident, the highest on its scale. Thankfully, no civilian deaths or discernible cancer rate increases can be attributed to radiation released from the accident, according to the United Nations Scientific Committee on the Effects of Atomic Radiation. However, over 1,000 died in the evacuation of the Fukushima prefecture. Most of the victims were elderly and vulnerable, and died primarily from exposure to cold weather, stress and inadequate access to healthcare and housing.

Fukushima Daiichi: 10 years on

March 1, 2021, 2:12PMNuclear NewsLake Barrett

The Fukushima Daiichi site before the accident. All images are provided courtesy of TEPCO unless noted otherwise.

It was a rather normal day back on March 11, 2011, at the Fukushima Daiichi nuclear plant before 2:45 p.m. That was the time when the Great Tohoku Earthquake struck, followed by a massive tsunami that caused three reactor meltdowns and forever changed the nuclear power industry in Japan and worldwide. Now, 10 years later, much has been learned and done to improve nuclear safety, and despite many challenges, significant progress is being made to decontaminate and defuel the extensively damaged Fukushima Daiichi reactor site. This is a summary of what happened, progress to date, current situation, and the outlook for the future there.

Farming in Fukushima

February 12, 2021, 11:57AMANS Nuclear Cafe

Screenshot of the video from Vice.

Vice News has published a video on YouTube that follows two farmers from the Fukushima Prefecture, Noboru Saito and Koji Furuyama. Saito, who grows many different crops on his farm, says that the rice grown in the area is consistently rated as the best. Furuyama specializes in peaches and explains his strategy to deal with the stigma of selling fruit from Fukushima: grow the best peaches in the world.

Decommissioning effort delayed for two Fukushima Daiichi buildings

April 22, 2020, 9:57AMRadwaste Solutions

Decommissioning work in parts of the Fukushima Daiichi plant in Japan has been delayed after engineers discovered that sandbags placed in the basements of buildings near Units 1 and 3 were found to contain excessive radiation levels. Tokyo Electric Power Company (TEPCO) operates the plant and is in charge of the decommissioning efforts following the accident caused by the earthquake and tsunami on March 11, 2011.

ANS backs Fukushima Daiichi treated water discharge plans

March 6, 2020, 12:44PMANS News

ANS President Marilyn Kray has expressed support for the continued recovery operations at the Fukushima Daiichi nuclear power plant, which sustained damage in the aftermath of a March 2011 earthquake and tsunami. Kray sent a letter on March 3 to Hiroshi Kajiyama, head of Japan’s Ministry of Economy, Trade, and Industry (METI), about the work of the ministry’s Subcommittee on Handling of the ALPS (Advanced Liquid Processing System) Treated Water and the findings of a February 2020 subcommittee report.

Anniversary Observations

March 11, 2019, 6:00AMANS Nuclear CafeAlan Medsker

The seismic event was huge and was felt all over the world.  With a moment magnitude of over 9.0, the earthquake and was the fourth largest ever in the more than 100 years of recorded history.  Huge land masses shifted as much as 2.4 meters, and the rotation of the earth was changed so that days were suddenly just a little (but measurable) bit shorter.  It had sped up the world.

Fukushima Three Years Later

March 11, 2014, 6:00AMANS Nuclear CafeWill Davis

KashiwazakiKariwa

Tokyo Electric Power Company's Kashiwazaki-Kariwa Nuclear Station; Units 6 and 7 were submitted for safety screening in September 2013.

In our collective memory, disturbing images played out on video around the world in the days following the apocalyptic Great Tohoku Earthquake and Tsunami have somewhat receded, even if they haven't lost their impact-images of rushing waters, floating vehicles, buildings and debris, massive (and unstoppable) outbreaks of fire, and implications of lives lost and lives ruined.

Decommissioning of Private Assets is Public Matter in Japan; TEPCO Forges Ahead

September 26, 2013, 1:56PMANS Nuclear CafeWill Davis

FukushimaDaiichi5and6breakwall

Fukushima Daiichi Units 5 (left) and 6 (right) seen in October 2012 behind the newly completed breakwall.

Earlier this month, Japanese Prime Minister Shinzo Abe conducted a visit to Tokyo Electric Power Company's Fukushima Daiichi nuclear station to examine conditions at the site and to gauge TEPCO's response to numerous ongoing problems. When Abe spoke to reporters after the visit, he mentioned (for reasons still unknown) that he had suggested to TEPCO that it decommission Unit 5 and Unit 6 on the site, so that it could focus its efforts squarely on the work required to recover from the nuclear accidents at Units 1, 2, and 3. This was reported with some surprise in many quarters.