Decommissioning Fukushima: not a task to take on alone?

While reports coming out of the IAEA signal Japan has made good progress in remediating the area around the damaged Fukushima plant, some in the industry believe the decommissioning task is not a job for a single nation.

By Elisabeth Jeffries

Additional reporting by K. Steiner-Dicks

Japan has made good progress in remediating the area around the damaged Fukushima plant, as well as planning the decommissioning process, according to two new reports from the International Atomic Energy Agency (IAEA). However, some believe the views made so far are too narrow given the huge decommissioning task that Japan, as a single nation, should understandably not take on its own.

The studies, which provide cautiously-phrased advice, are published following missions by IAEA experts to the area. They present an overall neutral picture of the Japanese authorities' and nuclear company efforts to remediate and plan decommissioning, using recommendations rather than cautionary notes.

In the case of the remediation investigation, the IAEA mission specifically considered the Special Decontamination area. This consists of zones known as the “restricted areas” located within a 20 km radius of the TEPCO Fukushima Daiichi NPP, and zones known as “deliberate evacuation areas”, where the annual effective dose for individuals was anticipated to exceed 20 millisieverts (mSv).

Progress made but better communication efforts required

The report states that the mission team saw good progress in the coordination of remediation in this area with reconstruction and revitalisation efforts. Progress and good practice are noted on several matters, such as stakeholder involvement and communication, outreach and better information for decision-making. It also notes efficient removal of contaminated material and good progress in remediating affected farmland.

The authors of the investigation also find significant progress in the development and implementation of temporary storage facilities by municipalities and the national government for contaminated materials generated by ongoing remediation activities.  Among several points, they also acknowledge the use of incineration as an effective technology for volume reduction of contaminated material.

A number of the IAEA notes relate to communication.  For example, one advisory note relates to acceptable dosage levels, stating that the organisations concerned should increase efforts to communicate that in remediation situations, any level of individual radiation dose in the range of 1-20 mSv per year is acceptable and in line with the international standards and recommendations. It urges stronger efforts to explain and communicate with the public on these issues. In addition, it suggests companies and institutions concerned should communicate the entire remediation and reconstruction programmes and how the various components interact.

Complex decommissioning

On decommissioning, the IAEA team notes the complexity of the situation and the difficult problems of contaminated water management, nuclear fuel and fuel debris removal that must be resolved to create a long-term stable conditions. They also state that Japan “appears to have adopted a well-oriented set of countermeasures” given these challenges.

The decommissioning study recommends more structured engagement with stakeholders and a revised communication strategy.  Other advisory points and acknowledgements are concerned with the decommissioning roadmap, spent fuel and fuel debris removal, contaminated water management and radioactive waste management. Ingress of groundwater into reactor and turbine buildings, public radiation exposure, licensing and regulatory requirements, remote decontamination and investigation technologies and other problems are also covered.

The IAEA team makes several recommendations.

For example, it advises TEPCO to consider alternative options and additional measures relating to fuel storage operations in the common spent fuel pool, as well as future fuel disposition. These cover areas such as the management of non-irradiated fuel, collection of data to assess fuel integrity, efforts to prevent cross contamination, techniques for removing rubble from fuel assembly internals and management of the different types of spent fuel.

It also states that a review of contaminated water management is necessary in order to find a sustainable solution.  This means considering resuming controlled discharges to the sea. TEPCO is advised to evaluate the radiological significance of discharges containing residual radionuclides so as to have a good scientific basis for taking decisions. Stakeholder engagement is urged relating to all final decisions on this issue.

In late September 3013, The Japan Times reported that Tokyo Electric Power Co. formally revised its groundwater flow simulation and believed up to 400 tons of contaminated water at the time of the report was seeping into the Pacific every day from the damaged Fukushima No. 1 nuclear plant. The previous estimate was about 300 tons per day.

Commenting on the IAEA reports, Mycle Schneider, an independent analyst on energy and nuclear policy that was recommended to Nuclear Energy Insider by a well-respected global think tank in London, suggests the IAEA view is too narrow. “The overall effect of the IAEA missions is not only necessarily very limited, it has a counterproductive side,” he argues. Schneider contends that the IAEA response is not sufficient in itself, though it may appear to be.

The analyst has worked as an IAEA consultant, presented at IAEA events and is a published author (The World Nuclear Industry Status Report 2012; An Independent Assessment 15 Months After Fukushima; author of the annualThe World Nuclear Industry Status Report).

“In the summer of 2013 it became obvious to the world that TEPCO, the NRA and the Japanese government are unable to cope with the disaster. It was the first time that Japanese officials have called for international assistance. The IAEA and a few former industry and regulatory officials from the UK and US seem to effectively respond to that call,” he says.

But he adds that “this is a planned, but mistaken impression. A few days lasting missions on site and in the region cannot cope with the incredible challenge of three melt-down reactors and a heavily damaged unit...the scope and complexity of this situation is beyond the capacity of a single nation.”

Schneider said: “The IAEA seems to be particularly concerned about the impact on the reputation of nuclear power [linked to] the continuing Fukushima disaster. In fact, in all of its reports, comments and recommendations, public relations play an important role.”

Beyond Japan

As Schneider suggests, a damaged nuclear plant disaster of this magnitude should have had more hands-on deck involvement from other nations at the onset of the event. Arguably, other nations, such as the US were monitoring the situation from afar as best they could as the news broke, based on data that they could compile and reasonably rely on. The beauty of hindsight is that the industry now has it and can make moves to prepare the international supply chain far in advance of such a disaster, natural or man-made.

But more decommissioning and nuclear waste lessons are yet to be learned as those commissioned to safely seal, recycle and house the used fuel and other forms of nuclear waste must also call in experts about contaminated water from the 2011 event still concerning other nations’ food supply, such as the Western Coast of the US.

In January of this year Loki Fish Company of Alaska reported that laboratory analysis of five salmon species harvested by its fishermen in Puget Sound and Southeast Alaska during 2013 showed no indications of ‘elevated’ radiation levels.

In response to customer concerns over radiation releases into the Pacific Ocean from Fukushima, fisherman-owned Loki Fish Company contracted with internationally accredited Eurofins Analytical Laboratories of Metaire, Louisiana to conduct radiation testing on seven stocks of wild salmon.

Loki harvests and direct markets wild salmon through King County Farmers’ Markets and through national wholesale distribution. Tests were conducted on Pink, Keta, Coho, Sockeye and King salmon from southeast Alaska, and Pink and Keta salmon from Puget Sound.

“Although the FDA contends that there is no evidence that radionuclides from Fukushima are present in Alaskan and Pacific Northwest seafood at a level that would be harmful to human health, it has not published results,” said Loki in a press statement. “Meanwhile unsubstantiated internet rumors regarding the safety of North Pacific seafood have become widespread.”

Pete Knutson, fisherman and co-owner of Loki , said of the rumours and test results: "As fishing families who put salmon on the table of consumers, we are as concerned as anyone about the health of our marine ecology. We have long been active in environmental issues which affect salmon stocks and believe that environmental defense needs to be driven by science, not fear."

All seven stocks of salmon were tested for the radionuclides associated with the nuclear plant failures in Japan: Cesium 134, Cesium 137, and Iodine 131. Of the seven samples, five did not register detectable levels of radionuclides. Two of the samples, however, still registered at trace levels – Alaskan Keta at 1.4Bq/kg for Cesium 137, and Alaskan Pink at 1.2Bq/kg for Cesium 134. Cesium-134 is a fingerprint for Fukushima's nuclear contamination. There were no detectable levels of iodine-131 in any samples.

To put those numbers in perspective, according to Loki, the critical limit set by the FDA for either Cesium-134 or Cesium-137 is 370 Bq/kg, far above the amount found in Loki’s Alaskan Keta and Pink salmon.

“I-131, Cs-134 and Cs-137 are artificially produced fission products, which do not naturally occur in food,” explains the Centre for Food Safety of the Government of Hong Kong (Special Administrative Region) on its web site.

“However, these radionuclides can get into food after it has been discharged into the environment from civil (e.g. nuclear reactor operations) or military nuclear operations (e.g. above-ground nuclear testing) and then pass through the food chain. Therefore, low levels of I-131, Cs-134 and Cs-137 may be present in food due to possible contamination from the environment,” said the government site.

IAEA still monitoring the situation

In February of this year, Japanese authorities informed the IAEA that a leak from an overflowing water storage tank at TEPCO's Fukushima Daiichi Nuclear Power Station was detected in the late evening of 19 February 2014. About 100 cubic metres of radioactive water leaked to the ground adjacent to the tank storage area before the leak was stopped about six hours later.

“Based on the information provided, IAEA experts consider that the leak poses no danger to the public,” said the IAEA.

IAEA experts also consider actions taken by Japan's Nuclear Regulatory Authority (NRA) following the leak to be appropriate. These include an NRA recommendation that TEPCO remove soil contaminated by the leaked water, which will reduce the risk that contaminated water will be spread further through rain and groundwater.

The IAEA noted that Japan has not asked the IAEA for any assistance in connection with the leak from the tank. However, the IAEA said in a press statement, without further clarification, that “it will continue monitoring developments”.

 

Later this month the IAEA is hosting an event called International Experts’ Meeting on Severe Accident Management in the Light of the Accident at the Fukushima Daiichi Nuclear Power Plant

http://www-pub.iaea.org/iaeameetings/46832/International-Experts-Meeting-on-Severe-Accident-Management-in-the-Light-of-the-Accident-at-the-Fukushima-Daiichi-Nuclear-Power-Plant

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