PERCEIVED RISK, TRUST, AND NUCLEAR WASTE:
LESSONS FROM YUCCA MOUNTAIN
Paul Slovic, Mark Layman, and James H. Flynn
June 23, 1991
Prepared for Riley E. Dunlap, Michael E. Kraft, and Eugene A. Rosa, eds., Public Opinion
and Nuclear Waste, Duke University Press.
Perceived Risk, Trust, and Nuclear Waste:
Lessons from Yucca Mountain
By the year 2000, the United States will have a projected 40,000 metric tons of spent
nuclear fuel stored and awaiting disposal at some 70 sites. By 2035, after all existing
nuclear plants have completed 40 years of operation, there will be approximately 85,000
metric tons (Technical Review Board, 1991). The amount of spent fuel needing disposal will
continue to grow with the relicensing of existing nuclear plants and the possible construction
of new facilities. The U.S. Department of Energy (DOE) has been under intense pressure
from Congress and the nuclear industry to dispose of this accumulating volume of high-level
waste since the passage of the Nuclear Waste Policy Act in 1982 and its amendment in 1987,
by which Yucca Mountain, Nevada was selected as the only candidate site for the nation's
first nuclear waste repository. The lack of a suitable solution to the waste problem is widely
viewed as an obstacle to further development of nuclear power and a threat to the continued
operation of existing reactors, besides being a safety hazard in its own right.
Yet, at this time, the DOE program has been brought to a halt by overwhelming
political opposition, fueled by perceptions of the public that the risks are immense (Flynn et
al., 1990; Kasperson, 1990; Kunreuther, Desvousges, & Slovic 1988; Nealey & Herbert,
1983; and this volume). These perceptions stand in stark contrast to the prevailing view of
the technical community, which believes that nuclear wastes can be disposed of safely, in
deep underground isolation. Officials from DOE, the nuclear industry, and their technical
experts are profoundly puzzled, frustrated, and disturbed by public and political opposition
that many of them believe is based upon irrationality and ignorance (see Table 1).
[Table 1 about here]
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Slovic, Layman, Flynn / Page 2
A number of important events during the past several years underscore the seriousness
of this problem.
1. Official opposition by the State of Nevada has increased substantially. In June,
1989, the Nevada legislature passed Assembly Bill 222, making it unlawful for any person or
governmental entity to store high-level radioactive waste in the State. The State Attorney
General subsequently issued an opinion that the Yucca Mountain site had been effectively
vetoed under a provision of the Nuclear Waste Policy Act. The Governor instructed state
agencies to disregard DOE's applications for environmental permits necessary to investigate
the site. The State and DOE initiated federal lawsuits over continuance of the program and
issuance of the permits needed for on-site studies. In September, 1990, the 9th U.S. Circuit
Court of Appeals ruled that the state had acted improperly and ordered Nevada officials to
issue the permits. To date, however, no permits have been issued.
2. In November, 1989, the DOE, admitting dissatisfaction with its earlier
assessments of the Yucca Mountain site, announced that it would essentially start over with,
"for the first time," an integrated, responsible plan. This plan would subject technical
studies to close outside scrutiny to ensure that decisions about Yucca Mountain would be
made "solely on the basis of solid scientific evidence" (Moore, 1989).
3. In July, 1990, the National Research Council's Board on Radioactive Waste
Management issued a strong critique of the DOE program, charging that DOE's insistence on
doing everything right the first time has misled the public by promising unattainable levels of
safety under a rigid schedule that is "... unrealistic, given the inherent uncertainties of this
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Slovic, Layman, Flynn / Page 3
unprecedented undertaking," and thus vulnerable to "'show stopping' problems and delays
that could lead to a further deterioration of public and scientific trust" (National Research
Council, 1990, p. 1). The Board recommended, instead, a more flexible approach,
permitting design and engineering changes as new information becomes available during
repository construction and operation.
Perceptions of risk from radiation, nuclear power, and nuclear waste play a pivotal
role in this story and need to be thoroughly understood if we are to make any progress in
resolving the current impasse. Although we already know a good deal about perceptions in
this domain (Slovic, 1990), most of our knowledge comes from rather general questions
(e.g., "How great is the risk of a nuclear waste repository compared with the risks of X, Y,
and Z?"). With some notable exceptions (Erikson, 1990; Lifton, 1976; Weart, 1988), there
have been few attempts to penetrate the surface veneer of nuclear fear and provide insight
into the nature and pervasiveness of people's concerns, the origins of these concerns, the
emotions that underlie them, their legitimacy, and their likely stability. Analysis of the
intense concerns associated with a nuclear waste repository is also important, we believe, for
understanding the role that perceived risk plays in the opposition to many other unwanted
facilities such as chemical-waste landfills and incinerators.
ATTITUDE, PERCEPTION, AND OPINION SURVEYS
There have been a number of surveys conducted recently to assess public attitudes,
perceptions, and opinions regarding the management of high-level radioactive wastes. We
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shall focus here on the results from a series of surveys we conducted in 1988 and 1989
(Flynn etal., 1990).
Details of these surveys are reported in Table 2. More than 3300 respondents were
questioned by telephone with regard to their perceptions of the risks and benefits associated
with a nuclear waste repository, their support or opposition for the DOE repository program,
their trust in the ability of DOE to manage the program, and their views on a variety of other
issues pertaining to radioactive-waste disposal. In addition to a national survey, data were
collected from three other populations of special interest: residents of Nevada, the state
selected as the site for the proposed national repository, and residents of Southern California
and Phoenix, the two major sources of visitors to Nevada. The Phoenix survey was less
extensive than the others and will be discussed in the next section. Respondents were
selected by means of a random digit dialing procedure. When telephone contact was made
with a household, the interviewer asked to speak to the person 18 years or older who had the
most recent birthday (to ensure random selection of respondents within each household).
Response rates were high (72% - 84%) in each of the surveys.
[Table 2 about here]
When asked to indicate the closest distance they would be willing to live from each of
10 facilities, the median distance from an underground nuclear waste repository was 200
miles in the national, Nevada,1 and Southern California surveys, twice the distance from the
next most undesirable facility, a chemical-waste landfill, and three to eight times the
distances from oil refineries, nuclear-power plants, and pesticide-manufacturing plants. In
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response to the statement "Highway and rail accidents will occur in transporting the wastes to
the repository site," the percentage of respondents who agreed or strongly agreed was 77.4%
in Nevada, 69.2% in California, and 71.6% nationally. Similar expectations of problems
were expressed with regard to future earthquake or volcanic activity at the site,
contamination of underground water supplies, and accidents while handling the material
during burial operations.
When asked whether a state that does not produce high-level nuclear wastes should
serve as a site for a nuclear waste repository, 67.9% of the Southern California and 76.0%
of the national respondents answered "no" (the question was not asked in Nevada). A
majority of those polled in the Southern California and National surveys judged a single
national repository to be the least fair of five disposal options (including storage at each
nuclear plant, in each state, and in each of several regions, and dual repositories in the East
and West).
Strong distrust of the DOE was evident from the responses to questions such as "The
U.S. Department of Energy can be trusted to provide prompt and full disclosure of any
accidents or serious problems with their nuclear waste management programs." In Southern
California, 67.5% either somewhat or strongly disagreed with this statement. The
corresponding rate of disagreement in the National survey was 68.1%.
Nevadans were asked whether or not they would vote in favor of a repository at
Yucca Mountain; 69.4% said they would vote against it, compared to 14.4% who would vote
for it. About 68% of the Nevadans surveyed said they agreed strongly with the statement
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"The State of Nevada should do all it can to stop the repository." Another 12.5% agreed
somewhat with this statement; only 16.0% disagreed. When asked whether or not they
favored Assembly Bill 222 that was passed in 1989 making it illegal to dispose of high-level
nuclear waste in Nevada, 74% were in favor and 18.4% opposed the bill. Finally, 73.6% of
Nevadans said that the state should continue to do all it can to oppose the repository even if
that means turning down benefits that may be offered by the federal government; 19.6% said
the state should stop fighting and make a deal.
Follow-up surveys of Nevada residents in October, 1990 and March, 1991 suggest
that opposition and distrust have continued to rise (Flynn, Mertz, & Slovic, 1991). The
percentage of Nevadans who would vote against a repository at Yucca Mountain increased
from 69.4% to 80.2%. In response to a request to indicate "how much you trust each of the
following to do what is right with regard to a nuclear waste repository at Yucca Mountain,"
the Governor of Nevada topped the list of officials, agencies, and institutions. DOE, the
Nuclear Regulatory Commission (NRC), and the U.S. Congress were the least trusted
entities (see Figure 1). Strong increases in trust were evident for the President, the
Governor of Nevada, and the Nevada State Legislature.2 In contrast, trust in DOE and NRC
declined between 1989 and 1991.
[Figure 1 about here]
Measures of trust in DOE, perceived risk, and opposition to a repository at Yucca
Mountain were highly interrelated. Table 3 illustrates the link between trust in DOE to
"provide full and prompt disclosure of any accidents or serious problems with a repository
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Slovic, Layman, Flynn / Page 7
program" and perception of risk from highway or rail accidents during the transportation of
wastes to a repository site. Table 4 illustrates the trust vs. perceived risk relationship with a
rating scale measure of trust in DOE to "do the right thing with regard to a nuclear waste
repository." In both tables, those who distrust DOE are much more likely to agree that
highway and rail accidents will occur than are those who trust DOE. Table 5 illustrates the
relationship between trust in DOE to disclose problems and the respondent's response to the
question "Would you vote for a repository at Yucca Mountain?" Among those who disagree
that DOE can be trusted to disclose accidents or serious problems with a repository program,
about 85-90% would vote against a repository at Yucca Mountain. The percentage of votes
against a repository drops to 65.1% for those who somewhat agree that DOE can be trusted
and falls further to 33.3% among the few who strongly agree that DOE can be trusted.
Other questions assessing trust, perceived risk, and opposition to a repository produced
relationships similar to those in Tables 3, 4, and 5.
[Tables 3, 4, and 5 about here]
IMAGERY AND PERCEPTION
Prior to answering any of the attitude or opinion questions, respondents in the
national, Southern California, and Nevada surveys, along with the 802 respondents in
Phoenix, were asked to free associate to the concept of a nuclear waste repository.
The potential for word associations to reveal the mental content of a person's
subjective experience was recognized by Plato and has a long history in psychology, going
back to Galton (1880), Wundt (1883), and Freud (1924). More recently, Szalay and Deese
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Slovic, Layman, Flynn / Page 8
(1978) have employed the method of continued associations to assess people's subjective
representative systems for a wide range of concepts. This method requires the subject to
make repeated associations to the same stimulus, for example,
war: soldier
war: fight
war: killing
war: etc.
Szalay and Deese argue that the method of continued associations is an efficient way
to determine the contents and representational systems of human minds without requiring
those contents to be expressed in the full discursive structure of language. In fact, we may
reveal ourselves through associations in ways we might find difficult to do if we were
required to spell out the full propositions behind these associations through answers to
questions. Evidence provided by Szalay and Deese and others demonstrates that responses
produced by the method of continued associations are not erratic and whimsical, but are
stable and relate clearly and naturally to a person's experiences and preferences. They are
organized and structured in much the same way as perceptions, beliefs, and attitudes.
A related view is provided by Fiske, Pratto, and Pavelchak (1983), who describe an
image as a "cognitive representation, a conception, or an idea, potentially containing both
concrete and abstract impressions; ... a mental picture, but not necessarily visual" (p. 42).
Cognitive images are often accompanied by affect and such affect-laden images have
been found to have important behavioral consequences. Prejudicial images give rise to
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discrimination (Hamilton, 1981). Images of politicians affect voting behavior (Campbell, et
al., 1960). Images of nuclear war affect an individual's level of antinuclear political activity
(Fiske, Pratto, & Pavelchak, 1983). Images of cities and states determine decisions about
places to vacation (Slovic, et al., in press) or attendance at conventions (Kunreuther &
Easterling, 1990).
The repository images were elicited using a version of the method of continued
associations adapted for a telephone interview. The elicitation interview proceeded as
follows:
My next question involves word association. For example, when I mention
the word "baseball," you might think of the World Series, Reggie Jackson,
summertime, or even hot dogs. Today I am interested in the first six thoughts
or images that come to mind when you think of an underground nuclear
waste repository.3 Think about an underground nuclear waste repository for a
minute. When you think about this underground nuclear waste repository,
what is the first thought or image that comes to mind?
What is the next thought or image you have when I say underground nuclear
waste repository?
Your next thought or image?
This continued until six associations were produced or the respondent drew a
blank.
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The 3,334 respondents in the four surveys produced a combined total of exactly
10,000 word-association images to the repository stimulus. The associations were examined
and were classified according to their content to 13 general or superordinate categories, one
of which was a miscellaneous category. All but one superordinate category contained
subordinate categories—in one case there were 17 subordinate categories that were judged to
fit the theme of the major category. All in all, there were 92 distinct categories. Many of
these contained multiple associations, judged to have similar meanings. For example, the
subcategory labeled Dangerous/Toxic, within the superordinate category labeled Negative
Consequences, included the terms danger, dangerous, unsafe, disaster, hazardous, poisonous,
and so on.
The 13 superordinate categories and their 92 subcategories contained 9439 word-
association images (94.4% of the total). Some 561 associations were left uncategorized
(5.6% of the total).4
Table 6 presents the 13 superordinate categories in order of their combined
frequencies across all four samples. The one exception to this ordering is the relatively large
miscellaneous category, which is presented last. The subordinate categories are also shown,
ordered by frequency within their superordinate category. Table 7 presents an ordering of
the subordinate categories without regard for the superordinate structure.
[Tables 6 and 7 about here]
The most arresting and most important finding is the extreme negative quality of these
images. The two dominant superordinate categories, Negative Consequences and Negative
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Slovic, Layman, Flynn / Page 11
Concepts accounted for more than 56% of the total number of images. The dominant
subordinate category, Dangerous/Toxic, contained almost 17% of the total number of
images. The five largest subordinate categories
la. Dangerous/Toxic 16.83 %
lb. Death/Sickness 7.83%
Ic. Environmental Damage 6.92%
Ha. Bad/Negative 6.81%
lib. Scary 4.01%
were thoroughly negative in affective quality and accounted for more than 42% of the total
number of images. The four most frequent single associations were dangerous (n = 539),
danger (n = 378), death (n = 306), and pollution (n = 276).
Positive imagery was rare. Category XII, Positive, accounted for only 1% of the
images. Other generally positive concepts, Necessary (Category LX), employment (Category
Xb), and money/income (Category Xc) combined to total only 2.5% of the images. The
response "safe" was given only 37 times (0.37%).
Other noteworthy features of the combined data are:
• There were 232 associations pertaining to war, annihilation, weapons, and things
military (Categories lie and VUb).
• There were 85 associations relating to the long duration of storage necessary for
nuclear wastes or the transfer of risk and responsibilities to future generations (XUJa).
• There were surprisingly few (38) transportation images (XIUc).
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The famous NIMBY position (not in my backyard) was expressed in 273 images
(Category lid).
Nuclear waste repositories are sometimes referred to derisively as "dumps."
Although dump imagery was definitely present, it was infrequent (40 associations).
Studies of risk perception have found that the risks of nuclear reactors and nuclear
wastes have a dread quality (8). There were definite signs of this in the images.
Although the word "dread" was never mentioned specifically, many of the responses
categorized as scary (lib) reflected this quality (e.g., fear, horror, apprehension,
terror).
Lack of trust in DOE or other governmental agents is a common finding in studies of
public perceptions of nuclear-waste management. Associations indicative of distrust
appeared in Category Hj, Negative Toward Decision Makers and Process, and
Categories HI and Vli, dealing with mistakes). A number of images in the
Bad/Negative category also seemed to reflect lack of trust (e.g. stupid, dumb,
illogical).
Jones et al. (1984) have attempted to characterize the key dimensions of stigma. Two
of their major defining characteristics of stigma are peril and negative aesthetic
qualities (ugliness, repulsion). These qualities dominate the repository images. Peril
is pervasive throughout Categories I and n and elsewhere and negative aesthetics form
the bulk of the subordinate categories bad/negative (Ila) and Decay, Slime, Smell
(Hh).
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The image frequencies were very similar from one survey to another. Demographic
differences were also small. The negativity of repository images was remarkably consistent
across men and women of different ages, incomes, education levels, and political
persuasions.
After free-associating to the repository stimulus, each respondent rated the affective
quality of his or her associations on a five-point scale ranging from extremely negative to
extremely positive. These affective ratings were highly correlated with the respondent's
attitudes and perceptions of risk. For example, Table 8 shows a strong relationship between
a person's rating of the first image they produced and their response to the question "Would
you vote for a repository at Yucca Mountain?" More than 90% of the persons whose first
image was judged very negative voted against a repository at Yucca Mountain; more than
half of the persons whose first image was judged positive voted in favor of the repository. A
similarly strong relationship was found between affective ratings of images and a person's
judgment of the likelihood of accidents or other problems at a repository. Negativity of the
image rating was also strongly related to support for the State of Nevada's opposition to the
repository program.
[Table 8 about here]
What was learned by asking more than 3300 people to associate freely to the concept
of a nuclear waste repository? The most obvious answer is that people don't like nuclear
waste. However, these images (as well as the responses to the attitude and opinion
questions) demonstrate an aversion so strong that to call it "negative" or a "dislike" hardly
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Slovic, Layman, Flynn / Page 14
does it justice. What these responses reveal are pervasive qualities of dread, revulsion, and
anger; the raw materials of stigmatization and political opposition.
Because nuclear waste is a by-product of an impressive technology capable of
producing massive amounts of energy without contributing to greenhouse gases, one might
expect to find associations to energy and its benefits—electricity, light, heat, employment,
health, progress, the good life-scattered among the images. Almost none were observed.
Moreover, people were not asked to reflect on nuclear waste; instead, they were
asked about a storage facility (Phoenix survey) or a repository (other surveys). One might
expect, following the predominant view of experts in this field, to find a substantial number
of repository images reflecting the qualities "necessary" and "safe" (see Table 1). Few
images of this kind were observed.
It appears that the repository has acquired the imagery of nuclear waste, through some
process of transference—guilt by association. The transference is so natural, so powerful,
that one state official involved in nuclear safety, upon hearing of these imagery results,
indignantly accused us of having biased our respondents by calling the facility a "nuclear
waste repository."
Evidence that the quality of repository imagery has not heretofore been appreciated
comes from exhortations by nuclear power proponents to please not use the term "dump"
when referring to the repository, because of the obvious connotations or imagery this word
conveys (Carter, 1987). Not only is dump or garbage imagery relatively infrequent in the
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observed responses, such images would appear rather benign in comparison to the more
prevalent responses.
HOW DID IT GET THIS WAY?
Imagery and attitudes so negative and so impervious to influence from the assessments
of technical experts must have very potent origins. Weart's scholarly analysis of images
shows that nuclear fears are deeply rooted in our social and cultural consciousness. He
argues persuasively that modern thinking about nuclear energy employs beliefs and symbols
that have been associated for centuries with the concept of transmutation-the passage through
destruction to rebirth. In the early decades of the 20th century, transmutation images became
centered on radioactivity, which was associated with
"uncanny rays that brought hideous death or miraculous new life; with mad
scientists and their ambiguous monsters; with cosmic secrets of death and life;
... and with weapons great enough to destroy the world ..." (Weart, 1988, p.
421).
But this concept of transmutation has a duality that is hardly evident in the imagery
we observed. Why has the destructive aspect predominated? The answer likely involves the
bombing of Hiroshima and Nagasaki which linked the frightening images to reality. The
sprouting of nuclear energy in the aftermath of the atomic bombing has led Smith (1988) to
observe:
Nuclear energy was conceived in secrecy, born in war, and first revealed to
the world in horror. No matter how much proponents try to separate the
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peaceful from the weapons atom, the connection is firmly embedded in the
minds of the public, (p. 62)
Research supports Smith's assertions. A study by Slovic, Lichtenstein, and Fischhoff
(1979) found that, even before the accident at Three Mile Island (TMI), people expected
nuclear-reactor accidents to lead to disasters of immense proportions. When asked to
describe the consequences of a "typical reactor accident," people's scenarios were found to
resemble scenarios of the aftermath of nuclear war. Replication of these studies after the
TMI event found even more extreme "images of disaster."5
Fiske, Pratto, and Pavelchak (1983) studied public images of nuclear war and
obtained results that were similar to our repository images. The dominant themes of nuclear
war were physical destruction (long-term, short-term, and immediate), death, injury,
weapons, politics, hell, oblivion, nothingness, pain, contamination, radiation, end of
civilization, and genetic damage. Dominant emotional images included fear, terror, worry,
and sadness, with anger, hate, helplessness, and peace mentioned somewhat less frequently.
The shared imagery of nuclear weapons, nuclear power, and nuclear waste may
explain some of the surprising results that have come from surveys that have examined
perceived risks for these various forms of nuclear hazards. A nuclear waste repository is
judged to pose risks at least as great as a nuclear power plant or a nuclear weapons test site
(Kunreuther, Desvousges, & Slovic, 1988). If asked to indicate the closest distance a facility
could be built from one's home before one would want to move to another place or actively
protest, people are far more averse to living near a nuclear waste repository than any other
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kind of facility studied, including a nuclear power plant, a chemical-waste landfill, or a
pesticide-manufacturing facility (Flynn et al., 1990).
Further insights into the special quality of nuclear fear are provided by Erikson
(1990), who draws attention to the broad, emerging theme of toxicity, both radioactive and
chemical, that characterizes a "whole new species of trouble" associated with modern
technological disasters. Erikson describes the exceptionally dread quality of technological
accidents that expose people to radiation and chemicals in ways that "contaminate rather than
merely damage; ... pollute, befoul, and taint rather than just create wreckage; ... penetrate
human tissue indirectly rather than wound the surface by assaults of a more straightforward
kind" (p. 120). Unlike natural disasters, these accidents are unbounded. Unlike
conventional disaster plots, they have no end. "Invisible contaminants remain a part of the
surroundings-absorbed into the grain of the landscape, the tissues of the body and, worst of
all, into the genetic material of the survivors. An 'all clear' is never sounded. The book of
accounts is never closed" (p. 121).
Another strong determiner of public perceptions is the continuing story of decades of
mishandling of wastes at the nation's military weapons facilities, operated by DOE (National
Academy of Sciences, 1989). Leakage from these facilities has resulted in widespread
contamination of the environment, projected to require more than $150 billion for cleanup
over the next 30 years. The recent revelation of unprecedented releases of radiation from the
Hanford, Washington weapons plant in the 1940s and 1950s (Marshall, 1990) will certainly
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compound the negative imagery associated with a nuclear waste repository and further
undermine public trust in government management of nuclear-waste disposal.
A CRISIS OF CONFIDENCE
Analysis of these survey data provides insight into the remarkably negative attitudes
towards radioactive waste disposal facilities and the impassioned opposition to government
efforts to site high-level and low-level waste repositories. The negativity of perceptions and
emotions associated with a repository are remarkable in light of the confidence that most
technical analysts and engineers have in their ability to dispose of radioactive materials
safely. Even the report of the National Research Council (1990), though highly concerned
about the difficulties of predicting the long-term performance of a repository, conceded that
"These uncertainties do not necessarily mean that the risks are significant, nor that the public
should reject efforts to site the repository" (p. 13).
Chauncey Starr (1985), pointing to the public's lack of concern about the risks from
tigers in urban zoos, has argued that "acceptance of any risk is more dependent on public
confidence in risk management than on the quantitative estimates of risk ..." (p. 98).
Public fears and opposition to nuclear-waste disposal plans can be seen as a "crisis of
confidence," a profound breakdown of trust in the scientific, governmental, and industrial
managers of nuclear technologies.
Viewing the nuclear-waste problem as one of distrust in risk management gives
additional insights into its difficulty. Social psychological studies (Rothbart & Park, 1986)
have validated "folk wisdom" by demonstrating that trust is a quality that is quickly lost and
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slowly regained.6 A single act of embezzlement is enough to convince us that our accountant
is untrustworthy. A subsequent opportunity to embezzle that is not taken does little to reduce
the degree of distrust. Indeed, 100 subsequent honest actions would probably do little restore
our trust in this individual.
In this light, the 1989 attempt by DOE to regain the confidence of the public, the
Congress, and the nuclear industry by simply rearranging its organizational chart and
promising to do a better job of management and science in the future (Moore, 1989) appears
naive. Trust, once lost, cannot be so easily restored. Similarly naive is the aim professed
by DOE officials and other nuclear-industry leaders to change public perception and gain
support by letting people see firsthand the safety of nuclear-waste management. The nature
of any low-probability, high-consequence threat is such that adverse events will demonstrate
riskiness but demonstrations of safety (or negligible risk) will require a very long time, free
of damaging incidents. The intense scrutiny given to nuclear power and nuclear-waste issues
by the news media (Mazur, 1990) insures that a stream of problems, occurring all over the
world, will be brought to the public's attention, continually eroding trust.
WHERE NEXT FOR NUCLEAR-WASTE DISPOSAL?
Although everyone appreciates the sophisticated engineering required to store nuclear
wastes safely, the political requirements necessary to design and implement a repository have
not similarly been appreciated. As a result, notes Jacob (1990):
"While vast resources have been expended on developing complex and
sophisticated technologies, the equally sophisticated political processes and
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Slovic, Layman, Flynn / Page 20
institutions required to develop a credible and legitimate strategy for nuclear
waste management have not been developed" (p. 164).
In the absence of a trustworthy process for siting, developing, and operating a nuclear
waste repository, the prospects for a short-term solution to the disposal problem seem
remote. The report of the National Research Council (1990) is quite sensitive to issues of
risk perception and trust, but makes the strong assumption that trust can be restored by a
process that openly recognizes the limits of technical understanding and does not aim to "get
it right the first time." It seems likely that such open admission of uncertainty and refusal to
guarantee safety might well have opposite effects from those intended-increased concern and
further deterioration of trust. Moreover, the NRC statement also assumes that DOE will
continue to manage the nuclear-waste program, thus failing to come to grips with the
difficulties that DOE will face in restoring its tainted image.
The lack of a trustworthy process for siting, developing, and operating a nuclear
waste repository has drawn a number of other comments and recommendations besides those
of the National Research Council. Weinberg (1989) drew an analogy between fear of
witches during the 15th through 17th centuries and today's fear of harm from radiation. He
hypothesized that "rad-waste phobia" may dissipate if the intelligentsia (read
environmentalists) say that such fears are unfounded, much as eventually happened with fears
of witches. Carter (1987) argued that "Trust will be gained by building a record of sure,
competent, open performance that gets good marks from independent technical peer
reviewers and that shows decent respect for the public's sensibilities and common sense" (p.
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416). He also recommended that the National Academy of Sciences undertake a study to
determine how an independent and credible process of peer review can be established to
increase public trust in repository siting and development and to determine how state and
local governments can best be given a voice in siting investigations and in oversight of actual
repository operations. Others have called for more radical changes such as creating new
organizations and developing procedures to ensure that state, local, and tribal governments
have a strong voice in siting decisions and oversight of actual repository operations (e.g.,
Advisory Panel, 1984; Bella, Mosher, & Calvo, 1988; Bord, 1987; Creighton, 1990; Jacob,
1990). In this spirit, an official of the Canadian government has argued for making
repository siting in that country voluntary by requiring public consent as an absolute
prerequisite for confirming any decision (Freeh, 1991).
Whatever steps are taken, it is unlikely that the current "crisis in confidence" will be
ended quickly or easily. We must settle in for a long effort to restore the public trust.
Krauskopf (1990) has noted that postponing the repository to an indefinite future can be
defended on a variety of technical grounds and points out that the choice between repository
construction or postponement ultimately rests upon the shoulders of the public and their
elected representatives. The problems of perception and trust described above imply that
postponement of a permanent repository may be the only politically viable option in the
foreseeable future.
In an address to the National Association of Regulatory Utility Commissioners in
November, 1990, Joseph Rhodes, Jr., himself a commissioner from Pennsylvania, pointed
Perceived Risk, Trust, and Nuclear Waste
Slovic, Layman, Flynn / Page 22
out the implications of the polls indicating that most Nevadans oppose the siting of a
repository anywhere in Nevada and want state leaders to oppose such siting with any means
available (Rhodes, 1990). "I can't imagine," said Rhodes, "that there will ever be a usable
Yucca Mountain Repository if the people of Nevada don't want it. . . There are just too
many ways to delay the program ..." (p. 6)?
What are the options in the light of dedicated public opposition to a permanent
underground repository? Rhodes lists and rejects several:
| Continuing on the present path in an attempt to site a permanent repository
(which Rhodes refers to as the modern equivalent of "pyramids underground")
is a costly and doomed effort.
| Permanent on-site storage is unsafe.
| Deploying a monitored retrievable storage (MRS) program is also politically
unacceptable. Without a viable program to develop a permanent repository,
the MRS would be seen, in effect, as the permanent site.
| Reprocessing the spent nuclear fuel is also politically unacceptable because of
concerns over nuclear-weapons proliferation. Moreover, reprocessing reduces
but does not eliminate high-level wastes and the record of managing
reprocessing residues at Hanford and other military sites is hardly
encouraging.
Rhodes concludes that the only viable option is to delay the siting of a permanent
repository for several decades and store the wastes on site in the interim - employing dry-
Perceived Risk, Trust, and Nuclear Waste
Slovic, Layman, Flynn / Page 23
cask storage that has been certified by NRC as being as safe as geological storage for 100 or
more years (Nuclear Regulatory Commission, 1990). Should this course of action be
followed, technical knowledge will undoubtedly advance greatly during this interim period.
Perceptions of risk and trust in government and industry may change greatly, too, if the
problem of establishing and maintaining trust is taken seriously.
BEYOND YUCCA MOUNTAIN
The story of Yucca Mountain has implications for environmental decision making that
transcend the conflicts and concerns surrounding the disposal of radioactive wastes. People's
perceptions of chemicals are almost as negative as their perceptions of radioactivity. Any
major facility that produces, uses, transports, or disposes of chemicals will face similar
problems originating from perceptions of risk that bear little resemblance to the risk
assessments of technical experts. No one is happy about the current state of affairs.
Industrialists, scientists, politicians, and the public are united only in their anger and
frustration about the ways that environmental risks are currently managed.
Restoration and preservation of trust in risk management needs to be given top
priority. A solution to the problem of trust is not immediately apparent. The problem is not
due to public ignorance or irrationality but is deeply rooted in the adversarial nature of our
social, institutional, legal, and political systems of risk management. Public relations won't
create trust. Aggressive and competent government regulation, coupled with increased public
involvement, oversight, and local control over decision making might.
Perceived Risk, Trust, and Nuclear Waste
Slovic, Layman, Flynn / Page 24
NOTES
1. The Nevada results reported in this section are based upon the 500 respondents in the
statewide survey.
2. The 1991 survey was conducted in thedays following theconclusion of the GulfWar
when President Bush's approval ratings had reached unprecedented levels.
3. Respondents in the Phoenix survey were asked to associate to the term "underground
nuclear waste storage facility."
4. A complete listing of all 10,000 images, including those that were not categorized, is
available from the authors.
5. The fact that the earliest technical risk assessments for nuclear power plants portrayed
"worst-case scenarios" of tens of thousands of deaths and devastation over geographic areas the
size of Pennsylvania likely contributed to such extreme images (see Ford, 1977). These early
projections received enormous publicity, as in the movie The China Syndrome.
6. Abraham Lincoln, in a letter to Alexander McClure, observed: "If you once forfeit
the confidence of your fellow citizens, you can never regain their respect and esteem."
7. Rhodes' assertion echoes an earlier statement made by a former DOE official, John
O'Leary, in an interview with Luther Carter:
"When you think of all the things a determined state can do, it's no contest,"
O'Leary told me, citing by way of example the regulatory authority a state has
with respect to its lands, highways, employment codes and the like. The federal
courts, he added, would strike down each of the state's blocking actions, but
meanwhile years would roll by and in a practical sense DOE's cause would be
lost (Carter, 1987, p. 185).
Perceived Risk, Trust, and Nuclear Waste
Slovic, Layman, Flynn / Page 25
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Perceived Risk, Trust, and Nuclear Waste
Slovic, Layman, Flynn / Page 29
Table 1
Some Viewpoints of Experts Regarding Public Perceptions
of the Risks from Nuclear-Waste Disposal
"Several years ago ... I talked with Sir John Hill, . . . chairman of the United Kingdom's
Atomic Energy Authority. 'I've never come across any industry where the public perception
of the problems is so totally different from the problems as seen by those of us in the industry
. . . ,' Hill told me. In Hill's view, the problem of radioactive waste disposal was, in a
technical sense, comparatively easy" (Carter, 1987, p. 9).
"Nuclear wastes can be sequestered with essentially no chance of any member of the public
receiving a non-stochastic dose of radiation. . . . Why is the public's perception of the nuclear
waste issue at such odds with the experts' perception?" (Weinberg, 1989, pp 1-2).
"The fourth major reason for public misunderstanding of nuclear power is a grossly unjustified
fear of the hazards from radioactive waste.... Often called an 'unsolved problem,' many
consider it to be the Achilles' heel of nuclear power. Seven states now have laws prohibiting
construction of nuclear power plants until the waste disposal issue is settled. On the other hand
there is general agreement among those scientists involved with waste management that
radioactive waste disposal is a rather trivial technical problem" (Cohen, 1983, p. 119).
"It is possible to estimate the risk [of a high-level nuclear waste repository] if the material is
buried as planned. It turns out it is ridiculously low . . . The risk is as negligible as it is
possible to imagine, yet the clamor about the subject has paralyzed the decision-making
authorities, and there is still no consensus solution. It is embarrassingly easy to solve the
technical problems, yet impossible to solve the political ones" (Lewis, 1990, p. 245-246).
Table 2
Survey Details
Perceived Risk, Trust, and Nuclear Waste
Slovic, Layman, Flynn / Page 30
Survey and Location Dates
Sample
Size
Response
Rate (%)
Phoenix 4/13 - 6/8/88 802 72
National 10/21 - 12/7/89 825 77
Southern California 12/6/89 - 1/1/90 801 77
Nevada
Statewide 9/25 - 10/15/89 500 74
Nye County 9/25 - 10/15/89 204 74
Lincoln County 9/25 - 10/15/89 101 84
Esmeralda County 9/25 - 10/15/89 101 77
Nevada Total 9/25 - 10/15/89 906 77
Perceived Risk, Trust, and Nuclear Waste
Slovic, Layman, Flynn / Page 31
Table 3
Relationship Between Trust in DOE and Perceived Risk of Transport Accidents
Highway and Rail Accidents Will Occur1'
DOE Can Be
Trusted"
Strongly
Disagree
Somewhat
Disagree Neutral
Somewhat
Agree
Strongly
Agree N
Strongly Disagree 3.4 6.0 2.2 34.5 53.9 230
Somewhat Disagree 5.7 13.6 5.0 51.4 24.3 140
Neutral 14.3 28.6 14.3 28.6 14.3 7
Somewhat Agree 2.6 22.1 7.8 49.4 18.2 77
Strongly Agree 25.0 25.0 10.7 14.3 25.0 28
X2 = 97.1; df = .16; p < .001.
Note: Cell entries are row percentages based upon data from the Nevada Survey.
a The Department of Energy can be trusted to provide full and prompt disclosure of any
accidents or serious problems with a repository program.
Highway and rail accidents will occur in transporting the wastes to the repository site.
Perceived Risk, Trust, and Nuclear Waste
Slovic, Layman, Flynn / Page 32
Table 4
Relationship Between Trust in DOE and Perceived Risk of Transport Accidents
Highway and Rail Accidents Will Occur*
Strongly Somewhat Somewhat Strongly
Trust Rating" Disagree Disagree Neutral Agree Agree N
0 5.7 5.7 1.4 31.4 55.7 70
1-4 3.7 13.2 3.7 37.5 41.9 136
5 5.1 9.3 6.8 44.9 33.9 118
6-9 5.3 13.0 3.8 50.4 27.5 131
10 17.2 24.1 10.3 17.2 31.0 29
X2 = 40.7; df = .16; p < .001.
Note: Cell entries are row percentages based upon data from the Nevada Survey.
a Based upon rating trust in DOE to do what is right with regard to a nuclear waste repository
(0 = no trust; 10 = complete trust).
b Highway and rail accidents will occur in transporting the wastes to the repository site.
Perceived Risk, Trust, and Nuclear Waste
Slovic, Layman, Flynn / Page 33
Table 5
Relationship Between Trust in DOE and Response to the Question
"Would You Vote for a Repository at Yucca Mountain?"
DOE Can Be Trusted to Disclose Any Problems
Strongly Somewhat Somewhat Strongly
Yucca Mountain Vote Disagree Disagree Neutral Agree Agree
Yes 8.3 14.4 33.3 34.9 66.7
No 91.7 85.6 66.7 65.1 33.3
N 204 118 6 63 21
X2 = 62.2; df = .4; p < .001.
Note: Cell entries are column percentages. Responses are based upon the survey of Nevada
residents.
Table 6
Perceived Risk, Trust, and Nuclear Waste
Slovic, Layman, Flynn / Page 34
Images of a Nuclear Waste Repository:
Totals for Four Surveys by Superordinate and Subordinate Categories
Number Number
of images of images
I. NEGATIVE CONSEQUENCES h Unpredictable U
a Dangerous / Toxic 1683 i Mistakes 8
b Death / Sickness 783 j Serious 7
c Environmental Damage 692 k Skeptical 5
d Leakage 216 1 Concerns - Other 14
e Destruction 133
18
Total 311
f Pain and Suffering VD. SOCIETAL INSTITUTIONS
g Uninhabitable 7 a Government / Industry 125
h Local Repository Area Consequences 6 b Military / Weapons 106
i Negative Consequences - Other 8 c Science, Technology, Research and Progress 42
Total 3546 d Political Process
Total
31
H. NEGATIVE CONCEPTS
681
304
a Bad / Negative Vm. ECOLOGY
b Scary 401 a Natural Environment 124
c Unnecessary / Opposed 296 b Food and Water Supply 25
d Not Near Me 273 c Climate 9
e War / Annihilation 126
41
Total 158
f Societally Unpopular K. NECESSARY '
g Crime and Corruption 40 a Necessary 156
h Decay / Slime / Smell 39
37
Total 156
i Darkness / Emptiness X. ECONOMICS
j Negative Toward Decision Makers and Process 32 a Cost 58
k Commands to Not Build or to Eliminate Them 24 b Employment 57
1 Wrong or Bad Solution 19 c Money / Income 29
m No Nuclear, Stop Producing 15 d Economics - Other 5
n Unjust 14
10
Total 149
o Violence XI. INFORMATION, KNOWLEDGE
p Prohibited 5 a Uninformed 57
q Negative - Other 15 b Unsure / Unknown 39
Total 2068 c Curiosity, Interest and Knowledge
d Media
24
m. LOCATIONS 9
a Non-Nevada Locations 245 e Information, Knowledge - Other 2
b Storage Location / Containers 243
237
Total 131
c Desert / Barren xn. POSITIVE
d Nevada / Las Vegas 227 a Positive, Unconcerned 59
e Waste / Garbage / Dumps 215 b Effective 25
f Isolated 107 c Improved Environment 9
g Facilities and Their Construction 66 d Feasible 3
h Bury It 30 e Positive - Other 1
i Locations - Other
Total
20
1390
Total 97
Xm. MISCELLANEOUS
a Future / Long LastingIV. RADIATION, PHYSICAL STATES 85
a Radiation / Nuclear 336 b Energy / Power 65
b Chemicals & Physical States (Liquids, Gases) 55 c Transportation 38
c Fire / Hot 33 d Find Alternatives 31
Total 424 e Natural Disasters (Potential or Actual)
f Population
29
V. SAFETY, SECURITY 22
a Safety 228 g Degree of Distance 21
b Facilities Security 44 h Neutral / Apathetic / Mixed Feelings 20
c Control, Containment and Cleanup 32 i Supervision / Responsibility 14
d Caution 27 j Public Figures 12
Total 331 k Fiction
1 Problem Avoidance
11
VI. CONCERNS 9
a Problems 119 m Inevitability 8
b Questions 58 n Faith 5
c Health 25 o O.K. If... 4
d Unsolvable 19
18
Total 374
e Family XIV. UNCATEGOR1ZED 561
f Uncontrolled 14
g Controversy 13 TOTAL NUMBER OF ITEMS 10000
Perceived Risk, Trust, and Nuclear Waste
Slovic, Layman, Flynn / Page 35
Table 7
Subordinate Categories Ordered by Decreasing Frequency
Number Number
of Images of Images
I. a Dangerous / Toxic 1683 xra. e Natural Disasters (Potential or Actual) 29
I. b Death / Sickness 783 X. c Money / Income 29
I. c Environmental Damage 692 V. d Caution 27
H. a Bad / Negative 681 VI. c Health 25
n. b Scary 401 vra. b Food and Water Supply 25
IV. a Radiation / Nuclear 336 xn. b Effective 25
n. c Unnecessary / Opposed 296 n. k Commands to Not Build or to Eliminate Them 24
n. d Not Near Me 273 XI. c Curiosity, Interest and Knowledge 24
m. a Non-Nevada Locations 245 xra. f Population 22
ra. b Storage Location / Containers 243 xra. g Degree of Distance 21
m. c Desert / Barren 237 in. i Locations - Other 20
V. a Safe and Secure 228 xra. h Neutral / Apathetic / Mixed Feelings 20
ra. d Nevada / Las Vegas 227 VI. d Unsolvable 19
I. d Leakage 216 n. l Wrong or Bad Solution 19
m. e Waste / Garbage / Dumps 215 VI. e Family 18
DC. a Necessary 156 i. f Pain and Suffering 18
I. e Destruction 133 n. q Negative - Other 15
H. e War / Annihilation 126 n. m Nuclear, Stop Producing 15
VH. a Government / Industry 125 VI. f Uncontrolled 14
vra. a Natural Environment 124 n. n Unjust 14
VI. a Problems 119 xra. i Supervision/ Responsibility 14
in. f Isolated 107 VI. 1 Concerns - Other 14
vn. b Military / Weapons 106 VI. g Controversy 13
xra. a Future / Long Lasting 85 xra. j Public Figures 12
in. g Facilities and Their Construction 66 xra. k Fiction 11
xm. b Energy / Power 65 VI. h Unpredictable 11
xn. a Positive, Unconcerned 59 n. o Violence 10
VI. b Questions 58 xn. c Improved Environment 9
X. a Cost 58 XI. d Media 9
XI. a Uninformed 57 vra. c Climate 9
X. b Employment 57 xra. l Problem Avoidance 9
IV. b Chemicals & Physical States (Liquids, Gases) 55 I. i Negative Consequences - Other 8
V. b Facilities Security 44 xra. m Inevitability 8
vn. c Science, Technology, Research and Progress 42 VI. i Mistakes 8
n. f Societally Unpopular 41 VI. j Serious 7
n. g Crime and Corruption 40 I- s Uninhabitable 7
n. h Decay / Slime / Smell 39 I. h Local Repository Area Consequences 6
XI. b Unsure / Unknown 39 X. d Economics - Other 5
xra. c Transportation 38 n. P Prohibited 5
n. i Darkness / Emptiness 37 xra. n Faith 5
rv. c Fire / Hot 33 VI. k Skeptical 5
V. c Control, Containment and Cleanup 32 xra. o O.K. If... 4
n. j Negative Toward Decision Makers and Process 32 xn. d Feasible 3
vn. d Political Process 31 XI. e Information, Knowledge - Other 2
xra. d Find Alternatives 31 xn. e Positive - Other 1
ra. h Bury It 30
Note: Roman numerals indicate superordinate categories.
Perceived Risk, Trust, and Nuclear Waste
Slovic, Layman, Flynn / Page 36
Table 8
Relationship Between Affective Rating of a Person's First Image of a Nuclear
Waste Repository and Their Response to the Question
"Would You Vote for a Repository at Yucca Mountain?"
Evaluation of the First Image
Very Somewhat Somewhat Very
Yucca Mountain Vote Negative Negative Neutral Positive Positive
Yes 8.9 17.6 38.9 54.2 60.7
No 91.1 82.4 61.1 45.8 39.3
N 305 34 18 24 28
Note: Cell entries are column percentages.
Responses based on a survey of Nevada residents.
X2 = 81.4; df = 4; p < .001.
Perceived Risk, Trust, and Nuclear Waste
Slovic, Layman, Flynn / Page 37
Figure Caption
Figure 1. Responses of Nevada residents when asked to rate their trust in federal, state,
and local officials and federal agencies to do what is right with regard to a nuclear waste
repository at Yucca Mountain.
TRUST ON YUCCA MOUNTAIN
State and Local Officials
Ratings for 1989 and 1991
Scale: 0 (no trust) to 10 (complete trust)
1989 1991 1989 1991 1989 1991 1989 1991 1989 1991
Governor Legislature State County City/Town
TRUST ON YUCCA MOUNTAIN
Federal Officials and Agencies
Ratings for 1989 and 1991
Scale: 0 (no trust) to 10 (complete trust)
1989 1991 1989 1991 1989 1991 1989 1991 1989 1991
President Congress EPA DOE NRC
1