epa.gov/research
technical BRIEF
BUILDING A SCIENTIFIC FOUNDATION FOR SOUND ENVIRONMENTAL DECISIONS
U.S. EMBASSY SCIENCE FELLOWS SUPPORT TO JAPAN:
OBSERVATIONS AND COMMENTARY ON REMEDIATION OF THE
AREAS OFF-SITE FROM THE FUKUSHIMA DAIICHI REACTORS
INTRODUCTION
Following the Tohoku earthquake and tsunami on March 11, 2011, Japan's Daiichi nuclear power
plant suffered damages resulting in the release of radiological contamination. This release is the
largest nuclear disaster since the Chernobyl disaster of 1986 and only the second disaster (along
with Chernobyl) to be rated Level 7 (the highest level) for safety significance on the logarithmic
International Nuclear Event Scale.1
Japan was profoundly impacted. The radioactive material settled around the Daiichi plant and
caused major contamination over large areas of the Fukushima Prefecture. The contamination
level (predominantly Cs-137 and Cs-134) was high enough to require decontamination of the
surrounding areas to protect human health and the environment. Fourteen nearby cities were
evacuated (Figure 1 right picture), and more than 100 cities beyond those will require remediation
(Figure 1 left picture).
Intensive Contamination Survey Area
Special Decontamination Area
Zones where residency is prohibited for
extended periods (5O millisieverts or more)
Zones being prepared for residents' return
(2O millisieverts or less)
Zones with restricted residency
(from more than 2O millisieverts to less
than 5O millisieverts)
Rezoning undecided
Figure 14. Status of the evacuated areas,, featuring new evacuation zones to be formed after reorganization
of restricted zones on April 2, 2013.
The Government of Japan (GOJ) has been facing the enormous challenge to remediate areas
affected by the nuclear incident and has charged its Ministry of the Environment (MOE) with the
off-site remediation under the Act on Special Measures. The Ministry has been pursuing various
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programs to assess the radiation exposure of the population in the contaminated areas and to
effectively decontaminate these areas.
EMBASSY SCIENCE FELLOWS
At the request of the MOE, the U.S. Department of State, through its Embassy Science Fellow
(ESF) Program, provided assistance to the GOJ through subject matter experts in radiological
decontamination, one from the U.S. Environmental Protection Agency (EPA) and two from the U.S.
Department of Energy (DOE) national laboratories. The SMEs provided recommendations on the
continued GOJ's off-site remediation activities. The fellows are Dr. Sang Don Lee from EPA, Dr.
Robert Sindelar from Savannah River National Laboratory and Mark Triplett from Pacific Northwest
National Laboratory. The ESF mission period was February 4 through March 29, 2013. As a team,
the ESFs collected resources (e.g., strategic plan, technical reports, policies) relevant to the GOJ's
remediation efforts by meeting with national and local government officials, visiting remediation
sites, and meeting with primary decontamination contractors.
The ESF team assessed the organizational systems (used for planning, execution, and regulation
of the cleanup), the details of technology application and the details of the decontamination field
practices.
They observed that the MOE was adapting to the unprecedented wide-area nuclear incident and
vigorously pursuing remediation of the contaminated areas to expedite return of the impacted area
to the people, including:
• rapidly mobilizing resources to respond;
• seeking, developing, testing, and applying innovative decontamination methods;
• enabling local communities to have a strong role in forming decontamination plans and in
siting waste storage facilities;
• providing public education materials regarding the radiation risks and the status of
decontamination efforts;
• establishing open communication with the prefectural and municipal governments and with
citizens regarding
decontamination activities;
and
• engaging the international
community to find the best
solutions for remediation.
To accomplish their mission, the
ESF team drew upon their
experience with large-scale DOE
and EPA projects to provide
information, lessons learned, and
suggestions of technologies that
might benefit the remediation
activities in Japan. The team,
through collaboration and
coordination with other US
government employees developed a
framework for remediation of a
cesium-contaminated populated
Radiation Protection
Decontamination
Waste Management
System
Remediation of the Environment Affected
By the Fukushima NPP Accident
Environmental
Monitoring
Cesium Behavior in
the Environment
Figure 2. Program Elements for an Environmental Remediation
System for a Populated Region Contaminated by Cesium
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region from a total systems perspective, as shown in Figure 2. Information gathered and evaluated
by the team was categorized into each of these elements. The gaps and needs addressed by this
work offered a novel and more in-depth perspective on Japan's current activities related to the
radioactive incident and also leads to enhanced preparedness for such incidents within the U.S.
MORE INFORMATION
The observations and recommendations of the ESF team are documented in a report entitled,
Report of the United States Embassy Science Fellows Support to the Government of Japan -
Ministry of The Environment, Observations and Commentary on Remediation of The Lands Off-
Site From the Fukushima Daiichi Reactors^July 2013, Washington DC: U.S. Environmental
Protection Agency. SRNL-RP-2013-00303. EPA/600/R-13/135.
http://iosen.env.go.ip/en/documents/pdf/workshop July 17-18 2013 04.pdf
Chapter 1 of the report summarizes the: (1) extent of initial contamination, (2) status of the
decontamination activities and (3) program elements of an environmental remediation system for a
populated land with cesium contamination.
Chapters 2 through 8 describe the observations of the ESF team with respect to the environmental
remediation program elements and offer both general and specific recommendations for
improvements within the remediation program elements.
CONTACT INFORMATION
For more information, visit the EPA Web site at www.epa.gov/nhsrc.
Technical Contact: Sang Don Lee (lee.sangdon@epa.gov)
General Feedback/Questions: Kathy Nickel (nickel.kathy@epa.gov)
REFERENCES
"Fukushima accident upgraded to severity level 7". IEEE Spectrum. April 12, 2011.
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