The Vulnerability of the Nevada Visitor Economy to a Repository at Yucca Mountain

This article reviews the studies commissioned by the Nevada Nuclear Waste Project Office to estimate the economic impact of a high-level nuclear waste repository at Yucca Mountain. Case studies found that visitor impacts occur for some analogous facilities, but not for others. Assessments of behavioral intent indicate that at least some economic agents would avoid visiting Nevada under repository scenarios. A third set of studies tested the risk-aversion and negative-imagery models of visitor decision making; people avoid visiting places associated with either a significant health risk or negative imagery, but it has yet to be shown that a repository would induce these perceptions in nearby places. In sum, the NWPO-sponsored studies suggest the potential for visitor impacts, but do confirm that these effects will occur.     

The Nevada Initiative: A Risk Communication Fiasco

The U.S. Congress has designated Yucca Mountain, Nevada as the only potential site to be studied for the nation's first high-level nuclear waste repository. People in Nevada strongly oppose the program, managed by the U.S. Department of Energy. Survey research shows that the public believes there are great risks from a repository program, in contrast to a majority of scientists who feel the risks are acceptably small. Delays in the repository program resulting in part from public opposition in Nevada have concerned the nuclear power industry, which collects the fees for the federal repository program and believes it needs the repository as a final disposal facility for its high-level nuclear wastes. To assist the repository program, the American Nuclear Energy Council (ANEC), an industry group, sponsored a massive advertising campaign in Nevada. The campaign attempted to assure people that the risks of a repository were small and that the repository studies should proceed. The campaign failed because its managers misunderstood the issues underlying the controversy, attempted a covert manipulation of public opinion that was revealed, and most importantly, lacked the public trust that was necessary to communicate credibly about the risks of a nuclear waste facility.     

Perceived Risk, Stigma, and Potential Economic Impacts of a High-Level Nuclear Waste Repository in Nevada

This study investigates the potential impacts of the proposed nuclear waste repository at Yucca Mountain, Nevada, upon tourism, retirement and job-related migration, and business development in Las Vegas and the state. Adverse impacts may be expected to result from perceptions of risk, stigmatization, and socially amplified reactions to "unfortunate events" associated with the repository (major and minor accidents, discoveries of radiation releases, evidence of mismanagement, attempts to sabotage or disrupt the facility, etc.). The conceptual underpinnings of risk perception, stigmatization, and social amplification are discussed and empirical data are presented to demonstrate how nuclear images associated with Las Vegas and the State of Nevada might trigger adverse economic effects. The possibility that intense negative imagery associated with the repository may cause significant harm to Nevada's economy can no longer be ignored by serious attempts to assess the risks and impacts of this unique facility. The behavioral processes described here appear relevant as well to the social impact assessment of any proposed facility that produces, uses, transports, or disposes of hazardous materials.     

Managing Nuclear Waste from Power Plants

National strategies to manage nuclear waste from commercial nuclear power plants are analyzed and compared. The current strategy is to try to operate a repository at Yucca Mountain, Nevada, to dispose of high-level nuclear waste underground. The main alternatives involve temporary above-ground storage at a centralized facility or next to nuclear power plants. If either of these is pursued now, the analysis assumes that a repository will be built in 2100 for waste not subsequently put to use. The analysis treats various uncertainties: whether a repository at Yucca Mountain would be licensed, possible theft and misuse of the waste, innovations in repository design and waste management, the potential availability of a cancer cure by 2100, and possible future uses of nuclear waste. The objectives used to compare alternatives include concerns for health and safety, environmental and socioeconomic impacts, and direct economic costs, as well as equity concerns (geographical, intergenerational, and procedural), indirect economic costs to electricity ratepayers, federal government responsibility to manage nuclear waste, and implications of theft and misuse of nuclear waste. The analysis shows that currently building an underground repository at Yucca Mountain is inferior to other available strategies by the equivalent of $10,000 million to $50,000 million. This strongly suggests that this policy should be reconsidered. A more detailed analysis using the framework presented would help to define a new national policy to manage nuclear waste.     

Public Attitudes Toward Siting a High-Level Nuclear Waste Repository in Nevada

This paper examines the sources of public opposition to a high-level nuclear waste repository among samples of 1001 residents of Nevada and a national sample of 1201 residents. Two models of choice are contrasted: A benefit-cost model and a risk-perception model of individual choice. The data suggest that the willingness of Nevada residents to accept a repository at Yucca Mountain depends upon subjective risk factors, especially the perceived seriousness of risk to future generations. Perceived risk depends in part on level of trust placed in the Department of Energy to manage a repository safely. Opposition to a local repository did not decrease significantly if compensation in the form of annual rebates, either ($1000, $3000, or $5000 per year for 20 years) were offered to residents. The public needs to be convinced before compensation is considered, that the repository will possess minimal risks to themselves as well as to future generations, and that the site currently targeted is suitable. One way to do this is through adoption of mitigation and control procedures such as strict federal standards and local control over the operation of the repository. The federal government should also consider returning to the fair procedure for selection between candidate sites specified in the initial Nuclear Waste Policy Act of 1982.     

On-Site Storage of High Level Nuclear Waste: Attitudes and Perceptions of Local Residents

No public policy issue has been as difficult as high-level nuclear waste. Debates continue regarding Yucca Mountain as a disposal site, and—more generally—the appropriateness of geologic disposal and the need to act quickly. Previous research has focused on possible social, political, and economic consequences of a facility in Nevada. Impacts have been predicted to be potentially large and to emanate mainly from stigmatization of the region due to increased perceptions of risk. Analogous impacts from leaving waste at power plants have been either ignored or assumed to be negligible. This paper presents survey results on attitudes of residents in three counties where nuclear waste is currently stored. Topics include perceived risk, knowledge of nuclear waste and radiation, and impacts on jobs, tourism, and housing values from leaving waste on site. Results are similar to what has been reported for Nevada; the public is concerned about possible adverse effects from on-site storage of waste.     

Waste Package Performance Evaluations for the Proposed High-Level Nuclear Waste Repository at Yucca Mountain

The evaluation studies of the proposed repository for long-term storage of spent nuclear fuel and high-level nuclear waste at Yucca Mountain, Nevada, are underway. Fulfillment of the requirements for limiting dose to the public, which includes containment of the radioactive waste emplaced in the proposed repository and subsequent slow release of radionuclides from the Engineered Barrier System (EBS) into the geosphere, will rely on a robust waste container design, among other EBS components. Part of the evaluation process involves sensitivity studies aimed at elucidating which model parameters contribute most to the waste package and overlying drip shield degradation characteristics. The model parameters identified for this study include (1) general corrosion rate parameters and (2) stress corrosion cracking (SCC) parameters. Temperature dependence and parameter uncertainty are evaluated for the general corrosion rate model parameters while for the SCC model parameters, uncertainty treatment of stress intensity factor, crack initiation threshold, and manufacturing flaw orientations are evaluated. Based on these evaluations new uncertainty distributions are generated and recommended for future analyses. Also, early waste package failures due to improper heat treatment were added to the waste package degradation model. The results of these investigations indicate that the waste package failure profiles are governed by the manufacturing flaw orientation model parameters.     

Bounding Estimates for Critical Events When Directly Disposing Highly Enriched Spent Nuclear Fuel in Unsaturated Tuff

This paper examines the possibility of criticality in a nuclear waste repository. The estimated probabilities are rough bounds and do not entirely dismiss the possibility of a critical condition; however, they do point to the difficulty of creating conditions under which a critical mass could be assembled (i.e., corrosion of containers, separation of neutron absorbers from the fissile material, and collapse or precipitation of the fissile material). In addition, should a criticality occur in or near a container, the bounding consequence calculations showed that fissions from one critical event are quite small (<˜10²⁰ fissions, if similar to aqueous and metal accidents and experiments). Furthermore, a reasonable upper bound of total critical events of 10²⁸ fissions corresponds to only 0.1% of the number of fissions represented by the spent nuclear fuel inventory in a repository containing 70,000 metric tons of heavy metal (MTHM) (the expected size for the proposed repository at Yucca Mountain, Nevada).     

Ramifications of Risk Measures in Implementing Quantitative Performance Assessment for the Proposed Radioactive Waste Repository at Yucca Mountain, Nevada, USA

As part of its preparation to review a potential license application from the U.S. Department of Energy (DOE), the U.S. Nuclear Regulatory Commission (NRC) is examining the performance of the proposed Yucca Mountain nuclear waste repository. In this regard, we evaluated postclosure repository performance using Monte Carlo analyses with an NRC-developed system model that has 950 input parameters, of which 330 are sampled to represent system uncertainties. The quantitative compliance criterion for dose was established by NRC to protect inhabitants who might be exposed to any releases from the repository. The NRC criterion limits the peak-of-the-mean dose, which in our analysis is estimated by averaging the potential exposure at any instant in time for all Monte Carlo realizations, and then determining the maximum value of the mean curve within 10000 years, the compliance period. This procedure contrasts in important ways with a more common measure of risk based on the mean of the ensemble of peaks from each Monte Carlo realization. The NRC chose the former (peak-of-the-mean) because it more correctly represents the risk to an exposed individual. Procedures for calculating risk in the expected case of slow repository degradation differ from those for low-probability cases of disruption by external forces such as volcanism. We also explored the possibility of risk dilution (i.e., lower calculated risk) that could result from arbitrarily defining wide probability distributions for certain parameters. Finally, our sensitivity analyses to identify influential parameters used two approaches: (1). the ensemble of doses from each Monte Carlo realization at the time of the peak risk (i.e., peak-of-the-mean) and (2). the ensemble of peak doses calculated from each realization within 10000 years. The latter measure appears to have more discriminatory power than the former for many parameters (based on the greater magnitude of the sensitivity coefficient), but can yield different rankings, especially for parameters that influence the timing of releases.     

Improbability of Igneous Intrusion Promoting a Critical Event in Spent Nuclear Fuel Disposed in Unsaturated Tuff

In their regulations, the U.S. Environmental Protection Agency and the U.S. Nuclear Regulatory Commission permit the omission of features, events, or processes with probabilities of <10(-4) in 10(4) yr (e.g., a constant frequency of <10(-8) per yr) in assessments of the performance of radioactive waste disposal systems. Igneous intrusion (or "volcanism") of a geologic repository at Yucca Mountain for radioactive waste is one disruptive event that has a probability with a range of uncertainty that straddles this regulatory criterion and is considered directly in performance assessment calculations. A self-sustained nuclear chain reaction (or "criticality") is another potentially disruptive event to consider, although it was never found to be important when evaluating the efficacy of radioactive waste disposal since the early 1970s. The thesis of this article is that the consideration of the joint event--volcanism and criticality--occurring in any 10,000-year period following closure can be eliminated from performance calculations at Yucca Mountain. The probability of the joint event must be less than the fairly well-accepted but low probability of volcanism. Furthermore, volcanism does not "remove" or "fail" existing hydrologic or geochemical constraints at Yucca Mountain that tend to prevent concentration of fissile material. Prior to general corrosion failure of waste packages, the mean release of fissile mass caused by a low-probability, igneous intrusive event is so small that the probability of a critical event is remote, even for highly enriched spent nuclear fuel owned by the U.S. Department of Energy. After widespread failure of packages occurs, the probability of the joint event is less than the probability of criticality because of the very small influence of volcanism on the mean fissile mass release. Hence, volcanism plays an insignificant role in inducing criticality over any 10(4)-yr period. We also argue that the Oklo reactors serve as a natural analogue and provide a rough bound on probability of criticality given favorable hydrologic or geochemical conditions on the scale of the repository that is less than 0.10. Because the product of this bound with the probability of volcanism represents the probability of the joint event and the product is less than 10(-4) in 10(4) yr, consideration of the joint event can be eliminated from performance calculations.     

The Origin and Role of Trust in Local Policy Elites’ Perceptions of High‐Voltage Power Line Installations in the State of Arkansas

The debate over an installation of high‐voltage power lines (HVPLs) has been intense, particularly in northwest Arkansas. Detractors claim that the installation will negatively affect both the natural environment and the local economy, which contains a large tourism component. By contrast, those in favor of installing HVPLs claim that the installation is necessary in order to reliably support the increasing demand for electric power. Using original data collected from a recent statewide Internet survey of 420 local policy elites in Arkansas, this article focuses on two key aspects. First, we examine how local policy elites’ perceptions of risks versus benefits of HVPL installation in their communities are influenced by their levels of trust toward information provided by various sources (e.g., energy industry, environmental groups, and government). Second, we utilize cultural theory to explain how the cultural worldviews of policy elites––specifically, egalitarianism, individualism, hierarchism, and fatalism––shape these levels of trust and HVPL benefit‐risk perceptions, while controlling for other factors claimed by previous literature, including levels of knowledge on energy‐related issues and demographic characteristics. In general, our analysis indicates that policy elites’ value‐oriented formation of HVPL benefit‐risk perceptions is partially due to the influence cultural values have on trust in information sources. We conclude this article by discussing broader implications for the origin and role of trust in policy elites’ decisions throughout the policy‐making process.     

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.     

A Model of Consumers' Risk Perceptions Toward Recombinant Bovine Growth Hormone (rbGH): The Impact of Risk Characteristics

This study estimates the effect risk characteristics, described as outrage factors by Hadden, have on consumers' risk perceptions toward the food-related biotechnology, recombinant bovine growth hormone (rbGH). The outrage factors applicable to milk from rbGH treated herds are involuntary risk exposure, unfamiliarity with the product's production process, unnatural product characteristics, lack of trust in regulator's ability to protect consumers in the marketplace, and consumers' inability to distinguish milk from rbGH treated herds compared to milk from untreated herds. An empirical analysis of data from a national survey of household food shoppers reveals that outrage factors mediate risk perceptions. The results support the inclusion of outrage factors into the risk perception model for the rbGH product, as they add significantly to the explanatory power of the model and therefore reduce bias compared to a simpler model of attitudinal and demographic factors. The study indicates that outrage factors which have a significant impact on risk perceptions are the lack of trust in the FDA as a food-related information source, and perceiving no consumer benefits from farmers' use of rbGH. Communication strategies to reduce consumer risk perceptions therefore could utilize agencies perceived as more trustworthy and emphasize the benefits of rbGH use to consumers.     

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.     

How a Nuclear Power Plant Accident Influences Acceptance of Nuclear Power: Results of a Longitudinal Study Before and After the Fukushima Disaster

Major nuclear accidents, such as the recent accident in Fukushima, Japan, have been shown to decrease the public's acceptance of nuclear power. However, little is known about how a serious accident affects people's acceptance of nuclear power and the determinants of acceptance. We conducted a longitudinal study (N= 790) in Switzerland: one survey was done five months before and one directly after the accident in Fukushima. We assessed acceptance, perceived risks, perceived benefits, and trust related to nuclear power stations. In our model, we assumed that both benefit and risk perceptions determine acceptance of nuclear power. We further hypothesized that trust influences benefit and risk perceptions and that trust before a disaster relates to trust after a disaster. Results showed that the acceptance and perceptions of nuclear power as well as its trust were more negative after the accident. In our model, perceived benefits and risks determined the acceptance of nuclear power stations both before and after Fukushima. Trust had strong effects on perceived benefits and risks, at both times. People's trust before Fukushima strongly influenced their trust after the accident. In addition, perceived benefits before Fukushima correlated with perceived benefits after the accident. Thus, the nuclear accident did not seem to have changed the relations between the determinants of acceptance. Even after a severe accident, the public may still consider the benefits as relevant, and trust remains important for determining their risk and benefit perceptions. A discussion of the benefits of nuclear power seems most likely to affect the public's acceptance of nuclear power, even after a nuclear accident.     

The Importance of Multiple Performance Criteria for Understanding Trust in Risk Managers

Effective risk management requires balancing several, sometimes competing, goals, such as protecting public health and ensuring cost control. Research examining public trust of risk managers has largely focused on trust that is unspecified or for a single goal. Yet it can be reasonable to have a high level of trust in one aspect of a target's performance but not another. Two studies involving redevelopment of contaminated land (Study 1) and drinking water standards (Study 2) present preliminary evidence on the value of distinguishing between performance criteria for understanding of trust. Study 1 assessed perceptions of several trust targets (councilors, developers, scientists, residents) on their competence (capacity to achieve goals) and willingness to take action under uncertainty for four criteria. Study 2 assessed competence, willingness, and trust for five criteria regarding a single government agency. In both studies overall trust in each target was significantly better explained by considering perceptions of their performance on multiple criteria than on the single criterion of public health. In Study 1, the influence of criteria also varied plausibly across trust targets (e.g., willingness to act under uncertainty increased trust in developers on cost control and councilors on local economic improvement, but decreased it for both targets on environmental protection). Study 2 showed that explained variance in trust increased with both dimension‐ and trust‐based measures of criteria. Further conceptual and methodological development of the notion of multiple trust criteria could benefit our understanding of stated trust judgments.     

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.     

Trust in Risk Management: A Model‐Based Review of Empirical Research

This review of studies of trust in risk management was designed, in part, to examine the relations between the reviewed research and the consensus model of trust that has recently emerged in other fields of study. The review begins by briefly elaborating the consensus views on the dimensionality and function of trust. It then describes the various models of trust that have been developed in the field of risk management, comparing them with the consensus approach. The findings of previous reviews are outlined, followed by a delineation of the open questions addressed by the present review, the method used, and the results. Finally, the findings of the review are discussed in relation to the important issue of trust asymmetry, the role of trust in risk management, and directions for future research. The consensus model specifies two conceptualizations of trust, each linked to particular types of antecedents. Relational trust, which is called trust in this review, is based on the relations between the trusting person and the other. Calculative trust, which is called confidence, is based on past behavior of the other and/or on constraints on future behavior. Results of this review showed that most studies of trust in risk management, while exploring matters of particular concern to the risk management community, were at least in part consistent with the consensus model. The review concludes by urging greater integration between the concerns of the former and the insights of the latter.     

You Have Been Framed! How Antecedents of Information Need Mediate the Effects of Risk Communication Messages

This study investigates the processes that mediate the effects of framing flood risks on people's information needs. Insight into the effects of risk frames is important for developing balanced risk communication that explains both risks and benefits of living near water. The research was inspired by the risk information seeking and processing model and related models. In a web‐based survey, respondents (n = 1,457) were randomly assigned to one of three communication frames or a control frame (experimental conditions). Each frame identically explained flood risk and additionally refined the message by emphasizing climate change, the quality of flood risk management, or the amenities of living near water. We tested the extent to which risk perceptions, trust, and affective responses mediate the framing effects on information need. As expected, the frames on average resulted in higher information need than the control frame. Attempts to lower fear appeal by stressing safety or amenities instead of climate change were marginally successful, a phenomenon that is known as a “negativity bias.” Framing effects were mediated by negative attributes (risk perception and negative affect) but not by positive attributes (trust and positive affect). This finding calls for theoretical refinement. Practically, communication messages will be more effective when they stimulate risk perceptions and evoke negative affect. However, arousal of fear may have unwanted side effects. For instance, fear arousal could lead to lower levels of trust in risk management among citizens. Regular monitoring of citizens’ attitudes is important to prevent extreme levels of distrust or cynicism.     

Perceptions of Risk and Vulnerability Following Exposure to a Major Natural Disaster: The Calgary Flood of 2013

Many studies have examined the general public's flood risk perceptions in the aftermath of local and regional flooding. However, relatively few studies have focused on large‐scale events that affect tens of thousands of people within an urban center. Similarly, in spite of previous research on flood risks, unresolved questions persist regarding the variables that might influence perceptions of risk and vulnerability, along with management preferences. In light of the opportunities presented by these knowledge gaps, the research reported here examined public perceptions of flood risk and vulnerability, and management preferences, within the city of Calgary in the aftermath of extensive flooding in 2013. Our findings, which come from an online survey of residents, reveal that direct experience with flooding is not a differentiating factor for risk perceptions when comparing evacuees with nonevacuees who might all experience future risks. However, we do find that judgments about vulnerability—as a function of how people perceive physical distance—do differ according to one's evacuation experience. Our results also indicate that concern about climate change is an important predictor of flood risk perceptions, as is trust in government risk managers. In terms of mitigation preferences, our results reveal differences in support for large infrastructure projects based on whether respondents feel they might actually benefit from them.