Local Acceptance of a High-Level Nuclear Waste Repository

The siting of nuclear waste facilities has been very difficult in all countries. Recent experience in Sweden indicates, however, that it may be possible, under certain circumstances, to gain local support for the siting of a high-level nuclear waste (HLNW) repository. The article reports on a study of attitudes and risk perceptions of people living in four municipalities in Sweden where HLNW siting was being intensely discussed at the political level, in media, and among the public. Data showed a relatively high level of consensus on acceptability of at least further investigation of the issue; in two cases local councils have since voted in favor of a go-ahead, and in one case only a very small majority defeated the issue. Models of policy attitudes showed that these were related to attitude to nuclear power, attributes of the perceived HLNW risk, and trust. Factors responsible for acceptance are discussed at several levels. One is the attitude to nuclear power, which is becoming more positive, probably because no viable alternatives are in sight. Other factors have to do with the extensive information programs conducted in these municipalities, and with the logical nature of the conclusion that they would be good candidates for hosting the national HLNW repository.     

Risk Assessment Criteria for Radioactive Waste Disposal

The assessment of radioactive waste disposal options in terms of the annual risk to the critical group can lead to ambiguities, which arise largely in defining what is meant by the critical group. Radically different risk estimates can be obtained, depending on whether statistical averaging is carried out before or after the critical group is located in the time dimension. The merits of two different approaches are discussed through simple thought experiments and mathematical models. A criterion based on lifetime risk to the critical group is suggested, which could be used to supplement the currently accepted annual risk Emits. The risks from both stochastic and nonstochastic radiation effects are taken into account.     

Reversing Nuclear Opposition: Evolving Public Acceptance of a Permanent Nuclear Waste Disposal Facility

Nuclear facilities have long been seen as the top of the list of locally unwanted land uses (LULUs), with nuclear waste repositories generating the greatest opposition. Focusing on the case of the Waste Isolation Pilot Plant (WIPP) in southern New Mexico, we test competing hypotheses concerning the sources of opposition and support for siting the facility, including demographics, proximity, political ideology, and partisanship, and the unfolding policy process over time. This study tracks the changes of risk perception and acceptance of WIPP over a decade, using measures taken from 35 statewide surveys of New Mexico citizens spanning an 11‐year period from fall 1990 to summer 2001. This time span includes periods before and after WIPP became operational. We find that acceptance of WIPP is greater among those whose residences are closest to the WIPP facility. Surprisingly, and contrary to expectations drawn from the broader literature, acceptance is also greater among those who live closest to the nuclear waste transportation route. We also find that ideology, partisanship, government approval, and broader environmental concerns influence support for WIPP acceptance. Finally, the sequence of procedural steps taken toward formal approval of WIPP by government agencies proved to be important to gaining public acceptance, the most significant being the opening of the WIPP facility itself.     

Quantitative Risk Assessment of the New York State Operated West Valley Radioactive Waste Disposal Area

This article is based on a quantitative risk assessment (QRA) that was performed on a radioactive waste disposal area within the Western New York Nuclear Service Center in western New York State. The QRA results were instrumental in the decision by the New York State Energy Research and Development Authority to support a strategy of in‐place management of the disposal area for another decade. The QRA methodology adopted for this first of a kind application was a scenario‐based approach in the framework of the triplet definition of risk (scenarios, likelihoods, consequences). The measure of risk is the frequency of occurrence of different levels of radiation dose to humans at prescribed locations. The risk from each scenario is determined by (1) the frequency of disruptive events or natural processes that cause a release of radioactive materials from the disposal area; (2) the physical form, quantity, and radionuclide content of the material that is released during each scenario; (3) distribution, dilution, and deposition of the released materials throughout the environment surrounding the disposal area; and (4) public exposure to the distributed material and the accumulated radiation dose from that exposure. The risks of the individual scenarios are assembled into a representation of the risk from the disposal area. In addition to quantifying the total risk to the public, the analysis ranks the importance of each contributing scenario, which facilitates taking corrective actions and implementing effective risk management. Perhaps most importantly, quantification of the uncertainties is an intrinsic part of the risk results. This approach to safety analysis has demonstrated many advantages of applying QRA principles to assessing the risk of facilities involving hazardous materials.     

Decidedly Different: Expert and Public Views of Risks from a Radioactive Waste Repository

A questionnaire with items that had been used in a national survey of the general public was administered to persons attending an American Nuclear Society meeting. The items asked about risks associated with high-level nuclear waste (HLNW), trust in nuclear-waste program managers, costs and benefits of a repository project, and images of a HLNW repository. The results suggest that nuclear industry experts may have very different opinions from the general public about most of these items and their images of a repository indicate a vastly different conceptual framework within which their opinions are formed.     

Probabilistic Risk Analysis for a High-Level Radioactive Waste Repository

A probabilistic risk analysis (PRA) for a high-level radioactive waste repository is very important since it gives an estimate of its health impacts, allowing comparisons to be made with the health impacts of competing technologies. However, it is extremely difficult to develop a credible PRA for a specific repository site because of large uncertainties in future climate, hydrology, geological processes, etc. At best, such a PRA would not be understandable to the public. An alternative proposed here is to develop a PRA for an average U.S. site, taking all properties of the site to be the U.S. average. The results are equivalent to the average results for numerous randomly selected sites. Such a PRA is presented here; it is easy to understand, and it is not susceptible to substantial uncertainty. Applying the results to a specific repository site then requires only a simple, intuitively acceptable "leap of faith" in assuming that with large expenditures of effort and money, experts can select a site that would be at least as secure as a randomly selected site.     

A Decision Theory Perspective on the Disposal of High-Level Radioactive Waste

In this paper the problem of high-level nuclear waste disposal is viewed as a five-stage, cascaded decision problem. The first four of these decisions having essentially been made, the work of recent years has been focused on the fifth stage, which concerns specifics of the repository design. The probabilistic performance assessment (PPA) work is viewed as the outcome prediction for this stage, and the site characterization work as the information gathering option. This brief examination of the proposed Yucca Mountain repository through a decision analysis framework resulted in three conclusions: (1) A decision theory approach to the process of selecting and characterizing Yucca Mountain would enhance public understanding of the issues and solutions to high-level waste management; (2) engineered systems are an attractive alternative to offset uncertainties in the containment capability of the natural setting and should receive greater emphasis in the design of the repository; and (3) a strategy of waste management should be adopted, as opposed to waste disposal, as it allows for incremental confirmation and confidence building of a permanent solution to the high-level waste problem.     

The Role of Performance Assessment in the Regulation of Underground Disposal of Radioactive Wastes: An International Perspective

Much has been written about the development and application of quantitative methods for estimating under uncertainty the long-term radiological performance of underground disposal of radioactive wastes. Until recently, interest has been focused almost entirely on the technical challenges regardless of the role of the organization responsible for these analyses. Now the dialogue between regulators, the repository developer or operator, and other interested parties in the decision-making process receives increasing attention, especially in view of some current difficulties in obtaining approvals to construct or operate deep facilities for intermediate or high-level wastes. Consequently, it is timely to consider the options for regulators' review and evaluation of safety submissions, at the various stages in the site selection to repository closure process, and to consider, especially, the role for performance assessment (PA) within the programs of a regulator both before and after delivery of such a submission. The origins and broad character of present regulations in the European Union (EU) and in the OECD countries are outlined and some regulatory PA reviewed. The issues raised are discussed, especially in regard to the interpretation of regulations, the dangers from the desire for simplicity in argument, the use of regulatory PA to review and challenge the PA in the safety case, and the effects of the relationship between proponent and regulator. Finally, a very limited analysis of the role of PA in public hearings is outlined and recommendations are made, together with proposals for improving the mechanisms for international collaboration on technical issues of regulatory concern.Until August 13, 1997, the author was employed as a Principal Pollution Inspector by the Environment Agency (EA) of England and Wales. Responsible for managing the development and application of the regulatory postclosure assessment capability of Her Majesty's Inspectorate of Pollution (HMIP) between 1982 and 1996, when HMIP was merged with the National Rivers Authority and the Waste Regulatory Authorities to form the EA on April 1, 1996. Represented HMIP/EA on a number of international committees related particularly to PA; 20 Bonser Road, Twickenham, Middlesex TW1 4RG, U.K.     

Trust as a Determinant of Opposition to a High-Level Radioactive Waste Repository: Analysis of a Structural Model

Residents in the State of Nevada hold strong opinions about the federal government's proposal to site the nation's first high-level radioactive waste repository at Yucca Mountain. The model developed in this study is designed to examine the relationship between public perceptions of risk, trust in risk management, and potential economic impacts of the current repository program using a confirmatory multivariate method known as covariance structure analysis. The data used to test the model was collected in a 1989 statewide survey of Nevada residents. The results indicate that, for a statewide sample, perceptions of potential economic benefits do not have a significant role in predicting support or opposition to the repository program. On the other hand, risk perceptions and the level of trust in repository management are closely related to each other and to positions on Yucca Mountain. Trust directly influences risk perceptions which, in turn, have a direct effect on the attitude toward the repository, and an indirect effect through perceived stigma effects.     

Nuclear Risk Management on Stage: A Decision Analysis Perspective on the UK's Committee on Radioactive Waste Management

In 2003, the UK government set up a broad-based Committee on radioactive waste management (CoRWM) to look at the UK's policy on radioactive waste management with a view to jumpstarting a stalled policy process. The committee's brief was to come up with a set of recommendations that would protect the public and the environment, and be capable of inspiring public confidence. After consulting widely with the public and stakeholders, and drawing on advice from scientists and other experts, CoRWM arrived at a remarkably well-received set of recommendations. On the basis of our experiences of working on CoRWM's multi-criteria decision analysis of different management options, study of CoRWM documentation, and interviews with committee members, we describe the explicit and implicit principles that guided CoRWM. We also give an account of the process by which CoRWM arrived at its conclusions, covering four phases: framing, shortlisting, option assessment, and integration; and four cross-cutting activities: public and stakeholder engagement (PSE), science and engineering input, ethics and social science input, and learning from overseas practice. We finish by outlining some of the key developments in the UK's radioactive waste management process, which followed on from the publication of CoRWM's report, and present our reflections for the benefit of the risk and decision analysts of future committees that, like CoRWM, are charged with recommending to government on the management of technically complex and risky technologies, drawing on extensive public and stakeholder consultation.     

Perceived Risks of Radioactive Waste Transport Through Oregon: Results of a Statewide Survey

Transportation of hazardous materials, and particularly radioactive wastes, on public highways has become an important risk management issue. The unfavorability of public attitudes regarding hazardous and nuclear wastes signals the potential for strong public opposition to programs for transporting these materials. This paper presents the results of a survey conducted to assess public reactions to a long-term nuclear waste transport program planned to follow a route through a portion of rural Oregon. The survey assessed a number of key risk perception issues, including perceived health and safety risks of nuclear waste transport, relative risks of transport vs. storage at an existing site, trust in state officials, and satisfaction with life in communities along the transport route. The survey identified a number of attitudes and concerns that need to be understood and considered by those in charge of designing and implementing the waste-transportation program.     

Attitudes and Risk Perceptions of Stakeholders in a Nuclear Waste Siting Issue

Stakeholders are often regarded as a critically important group in such issues as the siting of nuclear facilities. In this article, stakeholders were identified on the basis of self-reported activities with regard to a nuclear waste siting issue under debate in four communities. Data were obtained in an extensive mailed survey from a total of 2,548 respondents, approximately an equal number from each community. The overall response rate was 43.9%. Some of the results and telephone interviews with a sample of the nonrespondents indicated that the data are reasonably representative of the respective populations. Stakeholder activities were measured by 20 questions and combined with an index of stakeholder activity level, dichotomized at the 90th percentile. Stakeholders were found to have a higher level of education than others, but otherwise they did not differ in demographics. They did not tend to see risks in general as high, but were quite interested and involved in the nuclear waste siting issue. The stakeholder activity level correlated with risk perception and attitudes in the waste siting issue, but with different signs for those who were for and those who were opposed: stakeholders of both types had more extreme views than others, but in different directions. In addition, stakeholder opponents were much more likely to strongly espouse extreme statements regarding the project than were supporters who also were stakeholders. Implications for risk management and communication are discussed.     

A Comparison Between Probabilistic and Dempster‐Shafer Theory Approaches to Model Uncertainty Analysis in the Performance Assessment of Radioactive Waste Repositories

Model uncertainty is a primary source of uncertainty in the assessment of the performance of repositories for the disposal of nuclear wastes, due to the complexity of the system and the large spatial and temporal scales involved. This work considers multiple assumptions on the system behavior and corresponding alternative plausible modeling hypotheses. To characterize the uncertainty in the correctness of the different hypotheses, the opinions of different experts are treated probabilistically or, in alternative, by the belief and plausibility functions of the Dempster‐Shafer theory. A comparison is made with reference to a flow model for the evaluation of the hydraulic head distributions present at a radioactive waste repository site. Three experts are assumed available for the evaluation of the uncertainties associated with the hydrogeological properties of the repository and the groundwater flow mechanisms.     

Perception and Acceptance of Technological and Environmental Risks: Why Are Poor Countries Less Concerned?

The research has been aimed at answering two questions: (1) What factors impact perception and acceptance of technological and environmental hazards? (2) Why are rich societies involved more in protecting their environment and health than poor societies? Data has been collected from representative samples of two countries—Poland and Sweden. The results indicate that (1) contrary to earlier findings, the inverse relations between perceived benefits and dangers of hazards has not been observed, (2) acceptance of a risk has been mostly influenced by perceived benefits, (3) rejection of a risk has been mostly influenced by its perceived harmful consequences. Concerning the second question, it has been found that: (1) perceived hazard's danger and benefit is not the only factor that impacts its acceptance, and (2) a broader economic context can impact acceptance (tolerance) of hazards. It has been found that being aware of high dangers and not very high benefits of hazardous activities, Poles still have accepted them. Thus, Poles seem to follow an old proverb: “When one does not have what one likes, one has to like what one has.”     

Historical Relationship Between Performance Assessment for Radioactive Waste Disposal and Other Types of Risk Assessment

This article describes the evolution of the process for assessing the hazards of a geologic disposal system for radioactive waste and, similarly, nuclear power reactors, and the relationship of this process with other assessments of risk, particularly assessments of hazards from manufactured carcinogenic chemicals during use and disposal. This perspective reviews the common history of scientific concepts for risk assessment developed until the 1950s. Computational tools and techniques developed in the late 1950s and early 1960s to analyze the reliability of nuclear weapon delivery systems were adopted in the early 1970s for probabilistic risk assessment of nuclear power reactors, a technology for which behavior was unknown. In turn, these analyses became an important foundation for performance assessment of nuclear waste disposal in the late 1970s. The evaluation of risk to human health and the environment from chemical hazards is built on methods for assessing the dose response of radionuclides in the 1950s. Despite a shared background, however, societal events, often in the form of legislation, have affected the development path for risk assessment for human health, producing dissimilarities between these risk assessments and those for nuclear facilities. An important difference is the regulator's interest in accounting for uncertainty.     

基于改进高斯烟羽模型的废弃物处理设施负效应测度

废弃物处理设施的选址和运营是公众参与度较高的决策领域。负效应测度既是这类设施选址优化的焦点和难点,也是设施运营后负效应评价和治理的关键。根据风向、风速和其他气象资料设置典型情景;对高斯烟羽模型进行改进,建立基于情景的多点源、多污染气体种类的受影响点气体污染计量模型;开发了由污染气体浓度、气体毒害系数和恶臭因子决定的负效应测度函数;结合情景持续时间,建立较长时期内综合负效应测度模型。通过算例验证模型的效果并提出负效应治理策略。     

Total System Performance Assessment for Waste Disposal Using a Logic Tree Approach

The Electric Power Research Institute (EPRI) has sponsored the development of a model to assess the long-term, overall performance of the candidate spent fuel and high-level radioactive waste (HLW) disposal facility at Yucca Mountain, Nevada. The model simulates the processes that lead to HLW container corrosion, HLW mobilization from the spent fuel, and transport by groundwater, and contaminated groundwater usage by future hypothetical individuals leading to radiation doses to those individuals. The model must incorporate a multitude of complex, coupled processes across a variety of technical disciplines. Furthermore, because of the very long time frames involved in the modeling effort (10⁴ years), the relative lack of directly applicable data, and many uncertainties and variabilities in those data, a probabilistic approach to model development was necessary. The developers of the model chose a logic tree approach to represent uncertainties in both conceptual models and model parameter values. The developers felt the logic tree approach was the most appropriate. This paper discusses the value and use of logic trees applied to assessing the uncertainties in HLW disposal, the components of the model, and a few of the results of that model. The paper concludes with a comparison of logic trees and Monte Carlo approaches.     

Options in Radioactive Waste Management Revisited: A Proposed Framework for Robust Decision Making

Deregulation, with concurrent pressure on electricity utilities, has fundamentally changed the once-"closed" radioactive waste management system controlled by the so-called "nuclear establishment." Advocacy coalitions may change-who knows in which direction-but policy learning may also take place. This article presents a framework to evaluate the management options for a specified concept of "sustainability." When weighing the different objectives in view of the long-lasting potential danger of radiotoxic substances, the overall goal of a sound waste management system is to demonstrate safety. The first-priority objective of a disposal system, therefore, is its stability so that it can comply with the protection goal, that is, the long-term protection of humans and the environment from ionizing radiation. The complementary objective is flexibility, defined here as intervention potential. Because trade-offs within the "sustainability triangle" of ecology, economy, and society are unavoidable, the concept of "integral robustness"-both technical and societal-is introduced into radioactive waste management. A system is robust if it is not sensitive to significant parameter changes. In the present case, it has to have a conservative, passively stable design with built-in control and intervention mechanisms. With regard to technical implementation, a concept called "monitored long-term geological disposal" is presented. Such an "extended" final disposal concept emphasizes technical robustness, recognizes evaluation demands (for a potential break-off of a project), and enhances process-based transparency. This open approach admittedly sets high challenges with regard to technicalities as well as the institutional setting and the management process. It requires "mutual learning" by and from all stakeholders to achieve a truly sustainable radioactive waste management system.     

Competence-Based and Integrity-Based Trust as Predictors of Acceptance of Carbon Dioxide Capture and Storage (CCS)

Public trust in organizations that are involved in the management and use of new technologies affects lay judgments about the risks and benefits associated with these technologies. In turn, judgments about risks and benefits influence lay attitudes toward these technologies. The validity of this (indirect) effect of trust on lay attitudes toward new technologies, which is referred to as the causal chain account of trust, has up till now only been examined in correlational research. The two studies reported in this article used an experimental approach to more specifically test the causal chain account of trust in the context of carbon dioxide capture and storage technology (CCS). Complementing existing literature, the current studies explicitly distinguished between two different types of trust in organizations: competence-based trust (Study 1) and integrity-based trust (Study 2). In line with predictions, results showed that the organizational position regarding CCS implementation (pro versus con) more strongly affected people's risk and benefit perceptions and their subsequent acceptance of CCS when competence-based trust was high rather than low. In contrast, the organizational position had a greater impact on people's level of CCS acceptance when integrity-based trust was low rather than high.