This award will support a bilateral international workshop between U.S. and Japanese scientists. The workshop is being driven by the Fukushima nuclear power plant accident that was caused by the massive earthquake and subsequent Tsunami. The primary focus of the workshop is to bring together researchers in both the U.S. and Japan to define the research needed to better understand how to ascertain the quantity of released radioactive material. This is a problem that requires fundamental scientific understanding of a variety of physical processes and it also has substantial practical value for not only the Fukushima incident, but for any that may occur in the future.
Following the devastating earthquake and tsunami that severely damaged the nuclear power plant in Fukushima Japan, an unknown quantity of radioactive material was released into the air and water surrounding the crippled nuclear power plant. Assessments of the remaining nuclear fuel following the incident have allowed the scientific community to approach a consensus on the total amount of radioactive material released from the Fukushima Dai-ichi nuclear power plant (FD-NPP). What is still unclear, however, is the timing of the releases and how much of the radioactive material was released into the atmosphere versus directly into the nearby ocean. To address these ongoing challenges with this problem, the National Science Foundation (NSF) recently sponsored a workshop held at the National Center for Atmospheric Research (NCAR) that brought together an international group of researchers from academia, government labs, government agencies, private industry and included representatives from the Japan Atomic Energy Agency (JAEA), Japan Nuclear Safety Research Association (NSRA), and the Kansai Electric Power Company. The names and affiliations of the participants, plus all of the other conference materials that could be publically released (agenda, presentations, working group summaries) are currently available online (see: www.ral.ucar.edu/nsap/events/fukushima/). The goal of the workshop was to present current STE approaches, and available data for these approaches, and discuss how the current state-of-the-science can be extended to address these challenging unanswered questions related to the FD-NPP incident. A day and a half of technical presentations set the stage for a subsequent day of open discussions both among the workshop steering committee and within separate breakout sessions where everyone at the meeting participated. Five breakout sessions were organized around the following topics: (1) Observations, (2) Uncertainty and Physical Process Modeling, (3) Back-Trajectory STE Methods, (4) Non-Gradient Descent STE Methods, (5) Gradient Descent and Misc. STE Methods. The results and findings from both the formal presentations and follow-on discussions, as well as the breakout sessions, resulted in recommendations for scientific options that can be used to quantify the amount of radiation released from the Fukushima power plant, and inform the broader scientific community on how to better address this type of problem. During the workshop, participants identified a set of recommendations aimed to enhance our ability to address the challenges identified above and meet the need for improved information on radiation releases during nuclear power plant accidents. The first recommendation was to take better advantage of the knowledge gained and lessons learned from the FD-NPP incident. This includes creating a central database of observations and information from this incident that could be used in future investigations and algorithm development efforts by the research community. The second recommendation from the workshop participants stressed the need to further invest in the fundamental science associated with using radiation dosage in atmospheric STE. This topic has yet to be extensively studied and could be enhanced at a modest level of support to university and graduate student researchers. Third, the establishment of a glossary of common terminology that would be used among the various research communities working on STE problems would enhance the information sharing between groups that traditionally have worked on STE methodologies in isolation. Fourth, nominal environmental impacts for similar incidents could be pre-computed for nuclear power plants in high value/consequence locations and the results made part of the emergency response procedures. Fifth, the information gap immediately following FD-NPP incident could be addressed by hardening the existing observational platforms near nuclear power plants and by the establishment of an on-call, rapidly deployable set of instrumentation to replace or augment existing equipment. Finally, radiation STE methods and information on the associated uncertainties could also better be incorporated into the consequence management process by including STE information in the responding organizations training exercises. Overall, the FD-NPP disaster suggests a pressing need for nuclear power safety organizations and for the scientific community to revisit this topic. These needs and corresponding priorities can be identified through panels like the National Academy of Science in collaboration with government agencies (e.g. Department of Energy, Department of Homeland Security, Department of Defense, etc.) whom have relevant expertise. Finally, in addition to the scientific aspects of providing better estimates of the radiation releases and subsequent downwind hazard, the connection to the decision-making process could benefit from a more detailed examination and refinement of the connections back to the science.
