Report on “Radiation Disaster Recovery Studies”
Course Radioactivity environmental protection
Name Triyono Basuki○Regarding“Radiation Disaster Recovery Studies”（Describe your thoughts, the process you engaged in and your research progress regarding Recovery from
Radiation Disaster.）

1. Thoughts regarding Radiation disaster recovery
The Fukushima accident that occurred on March, 2011, has caused the multi-effect to human life,that is usually simplified into three aspects, environment, social and health aspect. Since it has been
9 years from the time of the accident, we have witnessed the recovery from radiation disaster
activities and its achievements. In this report, the philosophy of recovery after the disaster, key
activities in the Fukushima recovery process, some key challenges in the Fukushima recovery process,and the proposed future scenario for Fukushima recovery are shortly discussed.
The recovery from disaster, in my opinion, is a process to re-establish a sustainable humanenvironmental system. It should create something new, a system that is better, stronger, more
resilient than before, it is not just a process of returning situation like before the disaster. The mostimportant goal is to prevent the disaster from happening, if it is a human-caused disaster, and how
to create enough capacity for disaster response to minimize the effect from the disaster when thedisaster happened. A thorough risk mitigation is a key activity to be carried out for preventing thehuman-caused disaster. A very broad aspects are needed to create enough capacity for disaster
response. It spans from enhancing technological capacity to human and society capacity,
governmental and post-radiation disaster management capacity etc.
The Fukushima disaster that was caused by triple disaster (earthquake, tsunami and radiation) has
caused a complex post disaster problem, and the radiation disaster becomes the most challenging partof the post disaster recovery. The key activities for Fukushima recovery from radiation disasterconsisted of (1) protection of human health by establishing and increasing radiation monitoring andmeasurement capacity, (2) infrastructure rebuilding and environmental decontamination activitiesand (3) returning the evacuees to their home town or even inviting non Fukushima people to live inFukushima and re-starting the social activities such as school, businesses etc.
However, these recovery activities were not a smooth process. There are many challenges faced during
the process of recovery that complicate the recovery process. The challenge of recovery from theradiation disaster in Fukushima was caused by the weakness of radiation disaster response capacity.
This may be caused by the nature of nuclear accident as a rare accident with a big effect. In one side,
the government did not have enough post radiation disaster management capacity to respond to theradiation disaster. In the other side, Fukushima peoples did not have enough radiation disaster
literacy when the disaster happened. It further caused the additional challenge related to social
aspect such as public anxiety regarding the effect of radiation, problem of communication between
government and public, public distrust to government and scientists etc., that turned to be the mostchallenging problem.
Many initiatives have been dedicated to solve these social problems. Dialogue that involves many
parties (Fukushima peoples, scientists and government) is a good tool that has been used forestablishing mutual understanding, for example Fukushima Dialogue initiated by ICRP and ETHOS
in Fukushima. Other initiatives, such as individual consultation program, dissemination ofinformation program through magazine, homepage, public seminar etc., have increased the correct
public understanding about radiation. They facilitated the evacuees to independently decided toreturn or not return to Fukushima. Furthermore, some incentives and facilities are provided tofacilitate the re-establishment of social life and businesses by providing. However, resolving of thesesocial aspect related challenges will be a long process to be undergone.
Another challenge is regarding the decontamination activity. The radionuclides such as 137Cs exist in
the environment for a long time. Removing the contaminated soil is the option that has been done sofar. However, it is difficult to be applied for special area like forest. On the other hand, how and where
the collected contaminated soil will be disposed as final disposal is still a very challenging issue.
For the future, a multi-stakeholder approach (government, business, and society) should be a platform
for any decision and policy, such as regarding final disposal area of contaminated soil etc., and for
information dissemination and public discussion forum. Fukushima peoples, especially peoples residein Fukushima, should be the main actor in the multi-stakeholder approach, rather than treat themas a victim of a disaster. Furthermore, there should be a clear plan of Fukushima recovery in thefuture with clear key success indicators in each stage. This plan should be made and evaluated byusing a multi-stakeholder approach. Finally, the recovery process is not going to rebuild Fukushima
as before the accident. The recovery process should be intended to build more resilient and stronger
Fukushima that is not only important for Japan, but also for whole world especially the nuclear world.

2. Engagement in the recovery process
As a PhD student, I engaged in the recovery process as a scientist. I conducted research that related
to the Fukushima accident and finally I produced some scientific evidences. The scientific evidences
should be one of considerations for any policy and decision that will be made for recovery process. Myresearch topic is about 137Cs migration from forest catchment to water body and its contribution toair dose rate that may be useful for decontamination activity of Fukushima area.

3. Research progress
I have conducted environmental monitoring of Fukushima area, especially catchment area of water
body since 2016. Since that time, I have collected samples from two area which are Hibara lake area,
Yamagun, Fukushima and Ogi reservoir area, Kawauchi village, Fukushima as well as conducted air
dose rate measurement. I conducted measurement of radionuclides concentration in soil and sedimentof study area especially 134Cs and 137Cs. I conducted the resulted data analysis to investigate how Cs
moved in environment, the influencing factors etc. So far, I have published 4 scientific papers in peer
reviewed journal.

○Title of Doctoral Thesis
137Cs Migration from Sloped Forest Catchment to Water Body and Its Contribution to Air Dose Rate

○Summary of Doctoral Thesis（Describe so as to be easily understood, by relating it to“Radiation Disaster Recovery Studies”.）

The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident that occurred on March, 2011, caused
a substantial amount of radioactive materials released to the environment. Among the radioactivematerials released to the environment, radiocesium (134Cs and 137Cs) beside radioiodine (131I) is themost major released volatile radionuclide having a direct impact on land contamination. The longer
137Cs half-life (30.2 years) in comparison to 134Cs (2.06 years) and 131I (8 days) has made the 137Cs as

the main radionuclide of interest to be studied. Forest area covers more than 60% of the contaminatedzone and has higher radiocesium inventory in comparison to the other land use, that is a disadvantage
as forest is one of source of food. Furthermore, forest can be source of radioactive particulatecontamination for lower area like water body (river, lake, reservoir etc.) that can contaminate water
resource. The understanding of radiocesium migration behavior is key to the assessment for the longterm radiation hazard risk and its countermeasures. The radiocesium distribution and migration interrestrial environment after FDNPP accident have been widely investigated, however, there are stillsome questions about the factors that influence the migration. Furthermore, alternative method toestimate future radiocesium migration and air dose rate derived from radiocesium is still needed.
This research aims to investigate the factors that influence 137Cs migration from forest catchment towater body, to introduce a new method for investigation of 137Cs migration and for estimating thefuture air dose rate derived from 137Cs.
The study area is in Ogi reservoir catchment area, Kawauchi village, Fukushima, which is locatedabout 18 km southwest from FDNPP. Air dose measurement and soil and sediment core sampling
were conducted on March 15 and 16, 2018 in a steep sloped forest and transition zone of the catchment
area and reservoir. The air dose rate was measured by a portable gamma survey meter with a NaIdetector (ALOKA MYRATE PDR-111) about 1 m above the ground. The soil and sediment core samples
were cut each 2 cm and 1 cm increment, respectively. The samples were dried at room temperatureand further dried in oven (105o C, 24 hours). The prior dry sieving (2 mm sieve) was performed using
electric horizontally rotating sieve (SKH-01, AS ONE). The activities of 134Cs and 137Cs were measured
by gamma spectroscopy with HP Ge detector and multichannel analyzer (GEM 30-70, ORTEC), atenergy peak of 604 keV and 662 keV for 134Cs and 137Cs, respectively. Physicochemical property of thesoil (pH, Organic Matter content, Silt and clay fraction, Exchangeable cation, Cation exchange
capacity and base saturation) was also measured.
The initial study was conducted in Hibara Lake, Yama District, Fukushima. The results show theshallower accumulation of 137Cs in the sediment layer of lake closer to flat area but deeper
accumulation of 137Cs in the sediment layer of lake closer to slope surrounding area. The result shows
the importance of slope for 137Cs migration. And the result also shows the higher activity
concentration of 134Cs and 137Cs in silt and clay fraction of soil (particle size <75µm) than sand fraction,suggesting that the radiocesium migration occurred through soil fine particle migration.
The factors that influence radiocesium retention and migration were investigated. The results showthat the radioactive contamination is strongly retained in sloped forest area after 7 years. It was dueto the vertical migration as a dominant mode of radiocesium migration in forest. The high abundanceof organic matter and less fine particle in soil surface were factors that cause the radiocesium verticalmigration in forest. The role of soil bacteria was analyzed in migration of the radiocesium bylaboratory experiment. The result shows that soil bacteria have an ability to absorb Cs. Furthermore,soil bacteria are also capable to desorb Cs from soil matrices, probably through the decomposition ofbiomass and organic matter in the soil.
The ratio of 137Cs in soil to 137Cs in sediment ratio for investigation of radiocesium migration wasintroduced for the first time. It was assumed that 137Cs in sediment is related with 137Cs in soil. When
137Cs in soil decreases with time progress, 137Cs in sediment will increase with time progress. The

time dependency of soil to sediment ratio was shown, suggesting the potential of the ratio for
analyzing 137Cs migration in future.
The ratio of air dose rate 1 m above the ground to 137Cs inventory in the soil for estimating the future
dose derived from 137Cs was reported. It is by considering that there is a relation between 137Cs insoil and air dose rate. It is known that the ratio decreased in short time and then became relatively

stable after Chernobyl nuclear accident. We firstly applied the ratio to the FDNPP accident. We
discussed the ratio from the point of vertical migration of 137Cs that will be affected by the increaseof distance between 137Cs and the detector or geometry change and soil shielding effect. The ratio will
be relatively stable or less changeable after the immobilization of 137Cs in soil layer especially in soil
mineral layer.

○Other theses published in academic research journals
1. Radiation Measurements, (2020). https://doi.org/10.1016/j.radmeas.2020.106424. (IF: 1.5, PeerReview)
Air dose rate to 137Cs activity per unit area ratio for different land use 7 years after the nuclear
accident -Case of the slope catchment, Ogi reservoir, FukushimaT. Basuki, W. C. Bekelesi, M. Tsujimoto, S. Nakashima
2. AIP-CP, accepted (2020) (Peer Review)
Examination of Cs tolerant bacteria interaction with Cs+ in aqueous solution and soil byusing 137Cs tracer
T. Basuki, K. Inada, S. Nakashima
3. Radiation Safety Management, 19, 23-34 (2020). DOI 10.12950/rsm.190924 (Peer Review)
Investigation of radiocesium migration from land to waterbody using radiocesium distribution
and soil to sediment ratio: A case of the steep slope catchment area of Ogi reservoir, Kawauchi
Village, Fukushima
T. Basuki, W. C. Bekelesi, M. Tsujimoto, S. Nakashima
4. Journal of Radioanalytical and Nuclear Chemistry (2018). DOI 10.1007/s10967-018-5809-1 (IF:1.1, Peer Review)
Deposition Density of Cs-134 and Cs-137 and Particle Size Distribution of Soil and Sediment
Profile in Hibara Lake Area, Fukushima: an Investigation of Cs-134 and Cs-137 Indirect
Deposition into Lake from Surrounding Area
T. Basuki, S. Miyashita, M. Tsujimoto, and S. Nakashima

Additional publications
1. Environmental Monitoring and Assessment, (2019) 191: 27. DOI 10.1007/s10661-018-7160-y (IF:1.9, Peer Review)
Assessment of natural radioactivity in coals and coal combustion residues from a coal-based
thermoelectric plant in Bangladesh: Implications for radiological health hazards
M. A. Habib, T. Basuki, S. Miyashita, W. Bekelesi, S. Nakashima, K. Techato, R. Khan, A. B. K.
Majlis, K. Phoungthong
2. Radiochimica Acta (2018). DOI 10.1515/ract-2018-3044 (IF: 1.3, Peer Review)
Distribution of naturally occurring radionuclides in soil around a coal-based power plant and theirpotential radiological risk assessment
M. A. Habib, T. Basuki, S. Miyashita, W. Bekelesi, S. Nakashima, K. Phoungthong, R. Khan, M.
B. Rashid, A. R. M. T. Islam, K. Techato,