Catálogo de publicaciones - libros

Information gathering and dissemination is a crucial aspect of a resilient society during and after a major disruptive event. Neutron detection is particularly important when spontaneously fissioning isotopes are present, such as following a severe nuclear accident. Historically, most neutron detectors have been based on helium-3. Yet because the supply of helium-3 has greatly diminished in the past decade, it is of international interest to develop non-helium-3 based neutron detectors. The Water Neutron Detector (WaND) provides an efficient, non-toxic, and non-flammable alternative detector method. The WaND system is currently under investigation for the nondestructive assay of spent nuclear fuel to quantify plutonium content.

After the Fukushima accident, a new concept of nuclear safety arouse: engineering thinking facing extreme situations. One of the specificity of emergency situations being a rise of social demand on engineering process, safety scientist have to make an anti-dualist move in order to improve collaboration between social scientists and engineers. In this aim, this article studies a case of efficient collaboration: the Swiss Cheese Model (SCM) of accidents. Since the early 1990s, SCM of the psychologist James Reason has established itself as a reference in the etiology, investigation or prevention of accidents. This model happened to be the product of the collaboration between the psychologist and a nuclear engineer (John Wreathall). This article comes back on the journey of the SCM and its fathers. It is based on an exhaustive literature review of Reason’s work and interviews of Reason and Wreathall carried out in 2014. The study suggests that the success of the model is not so much due to appropriation of the work of the psychologist by the industrial community but to a complex process of co-production of knowledge and theories. To conclude, we try to highlight ways that should encourage, in the future, such collaborative ways of working.

This paper summarizes our previous works on neutronics analysis for the disposal of damaged fuels from Fukushima Daiichi reactors. Three major stages have been identified for the criticality safety assessment after disposal. In order to evaluate the criticality safety for certain repository conditions and engineered barriers designs, neutronics models have been defined for different stages, and numerical results have been calculated by a Monte-Carlo code MCNP. For stages when fissile nuclides in the damaged fuels remains in the vicinity of the engineered barriers, the neutron multiplicity (k) for a canister containing fuel debris surrounded by buffer was calculated over the leaching time. For the stage when fissile nuclides originated from multiple packages deposit in far-field host rocks, the critical masses for uranium depositions were studied for various rock types and geometries. The methodology presented in the present paper could be further improved and utilized to assist the repository system design and criticality safety assessment in the future.

When humans make decisions, they tend to rely on the heuristic approaches, instead of considering all available facts. When humans need to make decisions as a group, this tendency also seems true. However, there are some additional mechanisms that can only be observed in the group level, which are influence and conformity. Understanding these mechanisms and their process patterns is necessary to interfere and manipulate a group decision making in order to make a good group decision. This is particularly critical in emergency situations where decision making needs to be done under time and risk pressure. This paper proposes a model of group decision making process using I-P-O model, emphasizing the influence process in the group. Besides, this paper also explains an analysis towards a group decision making experiment in laboratory setting. The discussion process was observed to find the influence pattern among the members.

After Fukushima nuclear power plant accident, resilience engineering has emerged as a new paradigm of risk management, and the design of resilient energy system is getting more and more important. Energy model analysis based on mathematical programming contributes to discussing how to implement resilience into energy system by identifying quantitative suggestions. In this paper, as an example of such analysis, the authors try to derive possible appropriate measures to enhance electricity supply system resilience to successive nuclear power plants’ shut-down risk. The model developed in this paper is a dynamic power generation planning model, which considers nuclear power plants’ shut-down risk stochastically and identifies resilient capacity expansion in Japan from 2012 to 2030 under the uncertainty of the risk from a quantitative perspective. This resilient capacity expansion includes the necessity of alternative power resources and demand response compensating for supply capacity loss due to nuclear power plants’ shut-down, considering economic constraints. Simulation results successfully show the need for these measures in the capacity expansion. Importantly, the suggestion is not like a future prediction but a normative image of the system through the comprehensive incorporation of forecasted future parameters and scenarios. The more detailed the parameters and the scenarios are, the better image can be obtained. Learning from past accidents and updating our scientific knowledge base will detail the parameters and the scenarios and make energy model analysis very effective. It will tell us how to make resilient energy system.

The MPS-FE method, which is a hybrid method for Fluid-Structure Interaction (FSI) problems adopting the Finite Element method (FEM) for structure computation and Moving Particle Semi-implicit/Simulation (MPS) methods for free surface flow computation, was developed to utilize it in disaster-resilient design of important facilities and structures. In general free-surface flow simulation using the MPS method, wall boundaries are represented as fixed particles (wall particles) set as uniform grids, so the interface of fluid computation does not correspond to the interface structure computation in the conventional MPS-FE method. In this study, we develop an accurate and robust polygon wall boundary model, named Explicitly Represented Polygon (ERP) wall boundary model, in which the wall boundaries in the MPS method can be represented as planes that have same geometries as finite element surfaces.

Bioaccumulation of cesium with increasing trophic position is well known across nearly every ecosystem for most organisms. In the marine environmental, typical (concentration ratios (Bq/kg in tissue: Bq/kg in seawater) range from 50–100 in lower trophic levels to 300–10,000+ for apex predators. Recent surveys of 7 gelatinous organisms off the coast of Oregon ranging in trophic position from 1.0 to 3.0 revealed a concentration ratio maximum of 12.5 and typical concentration ratios no higher than 4.4. The implications on human diets and ecosystem shifts for large radiocesium releases are discussed.

Radioactive backgrounds establish the limit of sensitivity in detection systems for the general search scenario, and set the reasonably unavoidable dose limits for members of the public. Measurement of NORM isotopes in the air provides a unique opportunity to serve the dual goals of capturing temporal/meteorological NORM variations as well as coordinate public outreach/education of NORM exposure. The RadWatch Near-Realtime Air Monitor (RAM) stores meteorological and high resolution spectroscopy data as a function of time from six stories above UC Berkeley Campus. This data is served hourly to the public via radwatch.berkeley.edu/airsampling to demonstrate, not only the existence of NORM, but also the large variations observed in radioisotope air concentration. Clarity and transparency in this education effort are paramount, and complement the urgency of a ‘realtime’ system. In the future RadWatch will expand to interactive, networked devices to broaden the scope and engage the public.

The disposal of high level radioactive waste has fared no better in Japan since its legislation in 2000 than in most countries grappling with the same problem. This research aims to contribute to realizing some form of disposal in Japan, by suggesting ideas for an improved institutional scheme of policy making. This scheme concerns value judgments in decisions of technology use. Historically, implementing agencies have allowed limited debate on issues of value. What would develop if values previously neglected were given a chance to become a technical option of their own for the disposal of high level radioactive waste? This question has been taken out to the field, in the form of group interviews of young citizens. Here, the details and preliminary discussion of the fieldwork are described, as a temporary result of this study. A final section is dedicated to discuss the possible contributions of this study to the consideration of engineering resilience.

Drawing from in-depth anthropological research in the San Francisco Bay Area, looking at a community of scientists, experts, and other risk-conscious residents who are preparing for the next large earthquake, this article argues for an understanding of resilience as an overarching heuristic concept with the potential to articulate multiple forms of knowledge into a collaborative approach, associating scientists, experts, and residents. Building on the corpus of literature coming from Science and Technology Studies (STS), Geography and risk Disaster Studies, this article discusses the emergence of the concept of resilience and its articulation with the existing literature. Following this exploration, I will look at the implication such concept in the re-definition of knowledge and the categories of expertise as observed during my field research in the Bay Area of San Francisco. I find that resilience can be a useful concept only if the rigid definitions that have separated academic disciplines, as well as the concepts of “science” and “experience,” are recomposed in favor of a more integrated approach taking into account the multiple, and emerging, dimensions of knowledge.