Between the 7th and 14th November 2017, four members of the Interface Analysis Centre (IAC) visited the Fukushima Prefecture region of eastern Japan.
This was led by our Director for Science Professor Tom Scott, and generously funded through donations by a University of Bristol Alumnus alongside the Engineering and Physical Sciences Research Council (EPSRC).
The goals of this trip were:
- to undertake measurements of contamination using the unmanned aerial vehicle (UAV), developed by the IAC team
- to perform further physical sampling of sites contaminated by the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident at a number of newly accessible areas – recently derestricted by the Japanese Government
As well as collecting this valuable data, visits were made to collaborators who have supported the group's work.
Visit to CLADS at the Japan Atomic Energy Agency
The University of Bristol team alongside Dr Yukihiko Satou of the newly-opened Collaborative Laboratories for Advanced Decommissioning Sciences (CLADS), part of the Japan Atomic Energy Agency (JAEA) distributed laboratories.
Samples Taken From Contaminated Areas
The initial portion of the visit was spent around the Tomioka Town area, a region located less than 5 km to the south of the FDNPP – as a result, portions of the town are still to this day heavily contaminated and off-limits due to the high levels of radioactivity encountered. Owing to this and with assistance from collaborators at the Collaborative Laboratories for Advanced Decommissioning Sciences (CLADS) – part of the Japan Atomic Energy Agency (JAEA), a suite of “organic” (leaf, soil, moss, lichens and roadside sediment) samples were taken from across the area.
Such wide sampling was made to collect material sourced from each of the distinct plumes that originated from the plant – a result of the multiple reactor unit explosions / releases that occurred over the week-long period in March 2011. Upon their arrival at the University of Bristol, extensive analysis is planned on these samples – including high-resolution mass-spectrometry and individual isolation and tomography.
Whilst in Tomioka, a visit was made to Dr Yukihiko Satou at the brand new CLADS laboratories. A tour of the multi-million pound analytical facilities was kindly provided as well as allowing the team to conduct some initial screening of some of the samples that they had obtained.
Drone Surveillance of Radioactive Regions
During the latter portion of the trip, the team relocated to the Dakeonsen / Nihonmatsu area of Fukushima Prefecture. At approximately 60 km north-west of the FDNPP, the region exists at the very-tip of the main contamination plume. As a result, previous evacuation orders have since been lifted, however, low-levels of radioactivity still exist with numerous waste storage sites located across the area – produced from the widespread decontamination effort that has now completed.
This area hence represented a useful one for the validation of the current unmanned aerial platform, to test both the systems sensitivity in addition to its repeatability in conducting time-resolved analysis of a site. Even in windy conditions, the UAV was shown to not only produce highly-repeatable surveys of a user-defined area, but was also able to detect small activity differences across a sites profile (detailing the position of the waste bags from the background site structure).
Throughout fieldwork in Nihonmatsu, we were joined by Professor Yosuke Yamashiki from Kyoto University, who has supported all prior fieldwork and conference activities within Japan during this Fukushima study.
It is hoped that as a result of this latest visit to Fukushima Prefecture, with the data obtained and samples collected, that three to five scientific publications can result. These results will also provide valuable data for a number of PhD thesis works.
Return Visit to Bristol
Following the trip to Japan Dr Yukihiko Satou then returned the visit to the University of Bristol from the 21st-24th November. During this time Dr Satou gave a seminar to the whole IAC group on the research and activities at the CLADS facility, and explored further collaboration opportunities.