Social Values, Individual Judgments and Acceptance: The Case of High-Level Radioactive Waste in Germany

Abstract

The sustainable final disposal of high-level radioactive waste (HLW) remains an unresolved and highly controversially discussed issue, partly because of ecological, economic, and societal challenges and partly because of the risks the public associates with such disposal. Clearly, there will be little public acceptance of the project if citizens lack trust in responsible decision-makers and the site selection procedure. This endeavor will only be accepted if trust in the ongoing procedure is strengthened. We evaluated over 1800 comments from a German study (conducted in 2020) on the issue of final HLW disposal to answer the questions of how risk perceptions, trust, and acceptance are interrelated and what role other aspects, such as social values, play. By categorizing the comments, we obtained a different picture of opinions and identified the following needs circulating among the German population: the acceptance of a HLW repository or the site selection procedure depends particularly on the extent to which individual participants perceive the values of safety and fairness as fulfilled. When do they consider a repository safe, and when do they consider the procedure fair enough? The answers to these questions seem to depend strongly on the extent to which one’s own values are considered violated. The repository’s safety and the procedure’s fairness are essential. Moreover, instead on risks, respondents commented on safety. These concerns should be taken into account in the course of the site selection procedure to enable sustainable management and disposal of HLW.

1. Introduction

Although nuclear power generation has been regarded as a sustainable energy source within the European Union (EU) since 2022 [1], Germany has completed its nuclear phase-out. Other EU countries continue to rely on nuclear power. However, they all face a common challenge: the need for long-term safe disposal of high-level radioactive waste (HLW). In Germany, following a period of relative inactivity, a new site-selection procedure for a HLW repository was implemented in 2017. This new procedure presents a number of challenges in terms of environmental, economic, and social considerations, which must be addressed by waste management organizations (in this context, the term “waste management organizations” refers to the entities that are tasked with the implementation of HLW disposal. In Germany, the Federal Company for Radioactive Waste Disposal is responsible for identifying a suitable site and operating the disposal process. The Federal Office for the Safety of Nuclear Waste Management is the authority that is responsible for licensing the aforementioned activities) in order to achieve a sustainable repository management process that will be accepted by society [2] From a technical point of view, the procedure aims to investigate different sites in Germany according to scientific criteria in a staged process, and at its end, the geologically most suitable site should emerge [3,4]. This is based on an international consensus that final disposal in deep geological formations includes all necessary processes to ensure the long-term isolation of HLW from the biosphere. Nevertheless, the need for an integrative approach is also repeatedly emphasized in order to take into account “the technical complexity of disposal systems in relation to their broader societal context” [5]. Therefore, the German legislator initiated a science-based, transparent, and participatory procedure that offers a broader range of participation opportunities and communication than was common practice in the past, when the public’s opinion was given little to no consideration in decision-making processes in Germany [4]. From a sustainability perspective, social arrangements of this nature cannot be maintained over the long term unless they are perceived as fair [6]. According to Pascual et al. [7] (p. 813) “combinations of values-centred approaches are proposed to improve valuation and address barriers to uptake, ultimately leveraging transformative changes towards more just (that is, fair treatment of people and nature, including inter- and intragenerational equity) and sustainable futures”.

There is a general consensus among the technical disciplines on the need for a customized adapted safety concept for every HLW disposal project. Decisions must be made under uncertain conditions associated with a variety of of risks [8,9]. Following Aven and Renn, “[r]isk refers to uncertainty about and severity of the events and consequences (or outcomes) of an activity with respect to something that humans value” [10] (p. 6). As decades of social risk research show, lay people tend to overestimate the risks associated with radioactivity compared to other risks, such as driving a car [11,12,13]. Because no HLW repositories exist to date, there has been no experience with damaged facilities (only models and principles exist, see e.g., [14,15]). However, the amount of radioactivity from past uranium mining released in East Germany can reasonably illustrate that releases from a HLW repository would likely be much lower than those from an accident in a NPP [16]. Nevertheless, a repository may be judged very dangerous due to the general fear of radiation [17], negative attitudes toward the nuclear industry, and risk sensitivity, which are considered important factors in risk perception [18]—apart from the fact that some people are more risk-averse than others [19,20]. In addition, a recent study by Seidl et al. [21] shows that the positive aspects of final disposal, such as the protection of the biosphere, are almost never recognized by respondents. Moreover, people hardly rely on the usual risk definition’s quantification approach of probabilities and consequences but introduce other risk features such as ‘dread’ or fairness aspects [12,22]. Similar findings are observed in the perception of of HLW [23].

In general, aspects such as safety, transparency, and neutral information are highly valued by citizens and are important antecedents to judgment on the final disposal of HLW, as international studies have shown [24,25,26]. In other words, the geological disposal of HLW is primarily a technical problem; however, it is also necessary to consider the societal dimensions, including values, beliefs, and expectations, to enable a sustainable solution to the problem [5,27]. Following the recommendation of Seidl et al. [28], the acceptance of HLW disposal can be divided into different phases: acceptance of (i) the procedure, (ii) a possible decision for a repository site, and (iii) a repository in one’s community. Using their path model, the cited authors showed that trust is primarily relevant for explaining the acceptance of the ongoing procedure, whereas perceived potential risks are of great importance concerning the acceptance of a repository itself.

According to Siegrist [29], people are more likely to trust those who share their values. For example, Hendriks et al. [30] report that scientists communicating their findings to a lay audience are expected to show good moral character and values, such as fairness and honesty, and demonstrate integrity, whereas the public “may be sceptical or unaware of information incongruent with prior beliefs or values” [31] (p. 14081). Also Metzen emphasizes that a trustworthy scientist “needs to take the audience’s values into account because this shows goodwill towards the audience” and the care for other things the hearer values, not just knowledge [32] (p. 60), (see also [33], for sustainability topics in general). Lehtonen et al. [34] (p. 547) state that “the downsides of excessive trust and the potential virtues of mistrust and distrust are poorly recognized by practitioners” in the course of efforts to build trust in political practice, as well as in science. Consequently, a central challenge for appropriately designing decision-making and public participation processes “as [constituting] a mode of science communication” is to bring facts and values together in order to make better decisions and to avoid turning constructive mistrust into dysfunctional distrust [34] (p. 547).

If trust is linked to value similarity and values influence attitudes and/or behavior, one should investigate which values are relevant for the acceptance of the procedure and the repository. In his theory of basic human values, Schwartz defines values as “[…] desirable, transsituational goals, varying in importance, that serve as guiding principles in the life of a person or other social entity” (Schwartz’s 1994 [35]). His theory includes eleven recognized value types (self-direction, stimulation, hedonism, achievement, power, security, conformity, tradition, benevolence, universalism, and spirituality) and is based on Rokeach’s work “The Nature of Human Values.” Rokeach [36] distinguishes 36 abstract and concrete values, which he divides into 18 terminal and 18 instrumental values. However, in terms of acceptance of nuclear facilities, scholars and study respondents mention distributive and procedural fairness [37] and safety [24] as important values, which can be linked to the following overarching value types. For instance, the value of fairness (treating the public fairly in a procedure) refers to the value type of benevolence, while the value of safety (a repository shall be safe concerning its construction and operation) pertains to the value type of security [35]. Based on these findings, we define safety and fairness as social values that describe the desirable characteristics of the procedural and technical safety aspects of HLW management.

In light of Germany’s new approach to HLW management, we examine public opinion to gauge our knowledge of “where do we stand” in Germany in terms of acceptance of HLW disposal. Prior to our survey, there were few recent and comprehensive scientific studies that looked at the German public’s attitudes on the topic. These were mainly quantitative and descriptive [9,38], while only a few bottom-up studies were available for Germany [39,40]. However, for experts and decision-makers, it is important to know what current attitudes exist in the population and what factors influence these attitudes (see Section 4). Two questions are of interest here: what do people think about the procedure, and under what conditions might they accept a repository? The results can help improve future (quantitative) surveys on final disposal and communication with the public, as well as further develop theoretical concepts.

We analyzed the qualitative data obtained from the respondents’ comments in the survey conducted in 2020 [28]. At the end of the survey, we placed a text box for respondents to leave comments. We then examined the qualitative data to identify aspects important for the acceptance of (a) the current site selection procedure and (b) a future repository. We hypothesize that societal acceptance would be influenced not only by trust and risk perception but also by values such as procedural fairness or the repository’s safety. The value of fairness has been described as an important prerequisite for the acceptance of a repository [41,42]. Thus, traditional and altruistic (self-transcendent, ‘prosocial’) and probably biospheric values [37] are potentially relevant explanatory factors for accepting a HLW repository.

The remainder of this article is structured as follows. In Section 2, we explain our methodological approach. In Section 3, we present the selected empirical data, which we discuss in Section 4.

2. Material and Methods

In February/March 2020, we surveyed 5029 citizens of Germany via the marketing company respondi. We used an online questionnaire on various topics related to the issue of final HLW disposal, focusing on questions regarding trust. The final sample was representative of the general German population and fits the German statistical data for age (https://de.statista.com/statistik/daten/studie/1365/umfrage/bevoelkerung-deutschlands-nach-altersgruppen/ (accessed on 23 May 2025)) and education (https://www.bpb.de/kurz-knapp/zahlen-und-fakten/soziale-situation-in-deutschland/61656/bildungsstand-der-bevoelkerung/ (accessed on 23 May 2025)). The usable sample consisted of 4690 respondents, divided into 2340 women and 2344 men (6 persons did not identify their gender). Of the respondents aged between 16 and 69 (age groups: 16–21 years (n = 429), 22–35 years (n = 1143), 36–49 years (n = 1167), 50–60 years (n = 1192), and 61–69 years (n = 759)), 43% had finished primary school, 49% had attained a secondary education, and 8% had obtained a university degree.

At the end of the survey, respondents were offered the option to add comments. The respondents were free to express additional statements in their own words; 2076 respondents took advantage of this opportunity. In the first step, 182 comments were excluded from the analysis because they lacked any substance (e.g., “tree”, “Thank you”).

In the second step, we evaluated 1894 comments in depth using an iterative process following the methodology of content analysis [43]. Therefore, the results do not claim to be representative, but they do offer insightful insights into opinions and perspectives that exist within German society. The numbers for education are only slightly different from the main sample (including those who did not fill in a comment): 52.5% had secondary education, 9.6% had some university degree, and 37.9% had finished school.

The comments were divided into two equal sets, and two authors read one set each. In the next step, the comments were coded and assigned to different categories independently by the two authors. The assigned comments were then switched, and each author checked the other’s judgment. If there was any doubt regarding an assignment, this difference was discussed, and the assignment was changed if deemed necessary (for instance, codings were changed after consent, or a comment was assigned to more than one category). Finally, the assigned comments were discussed with the third author, who was not involved in the initial categorization process. The category system proposed by Stefanelli et al. [24], who studied public opinions on plans for an HLW repository in Switzerland, served as the basis for categorization. Their study used 13 main categories based on a classification previously developed by Seidl et al. [25]. The latter study investigated individuals’ attitudes and values gathered from 42 personal interviews. We partially modified and renamed the categories (Table S1) to adapt them to our sample’s comments (

Table 1. Overview of this study’s categories and those of previous studies (categories covered in this paper are in bold font).

Category	Frequency	Men	Women	Age Ø
Disposal/location	412	56%	44%	48.5
Justice/responsibility	209	54%	46%	49.1
Safety	187	52%	47%	49.5
Politics/procedures	174	55%	45%	46.5
Emotions	168	42%	58%	48.7
Cause/nuclear power	160	48%	52%	46.2
Necessity	127	46%	54%	46.7
Risks	98	42%	57%	46.6
Time period/future	79	62%	38%	52.9
Science/research	75	59%	41%	48.5
Economy/lobbyism	74	70%	30%	47.6
Repository	36	67%	33%	47.4

). In doing so, we ensured individual opinions were not excluded by using an overly rigid system of categories.

In the second phase, we identified the comments that addressed trust, risks, and benefits. We checked whether we could find indications of values and ethical aspects, which we have already referred to at the beginning, concerning our theoretical considerations. We kept in mind that our focus was on citizens’ attitudes regarding the current site selection procedure and an imagined future repository.

Approximately 61% (n = 721) of the comments were assigned to a single category, while 39% (n = 452) were distributed across more than one category due to the breadth of their content. Selected results are presented and discussed in the next section.

3. Results

This section should provide a concise and precise description of the experimental results, their interpretation, and the experimental conclusions that can be drawn.

3.1. Frequency of Comments by Categories

The Supplementary Table S1 shows the frequency of comments in each category, as well as the respective shares of men’s and women’s comments. As shown, the category Disposal/location has the most entries, followed by Responsibility/justice. Remarkably, Risks (n = 98) was less frequently mentioned than Safety (n = 187). For details, see Section 3.3.

Concerning gender differences, women commented more often in the categories of Emotions and Risk, whereas the category Economy/lobbyism stands out (n = 70 versus n = 30) in favor of men. Thus, men are more likely to comment on economic accounts than women. We obtained a similar result, albeit less pronounced, for the Repository (n = 67 versus n = 33) and Period/time (n = 62 versus n = 38) categories. Moreover, older respondents (53 years on average) more often mention the latter category. Additionally, the respondents whose comments were categorized under Safety and Responsibility/justice were older on average. In the following sections, we name the categories illustrated by quotes from the original statements.

3.2. Values

We found value-related and ethical aspects in the comments. Most often, these are linked to the procedure (e.g., political interference). The Political procedure itself is mentioned relatively often (n = 79), followed by Sufficient information (n = 28) that should be provided by the officials and then by Transparency (n = 24) of the procedure (

Table 2. Subcategories of Politics/procedure.

Main Category	Subcategories	Frequency
Politics/procedure Addresses conceptual and technical expectations of the site selection procedure	Political procedure	79
	Sufficient information	28
	Transparency	24
	Fairness	17
	Independence/neutrality	15
	Institutions	10
	Foreign countries/Germany as example	1

).

A variety of comments related to the procedure of finding a proper repository site and the government’s role in leading this procedure refer to the demand for Sufficient information (n = 28) and Transparency (n = 24) about what is going on. The demand for transparency can be differentiated in two ways. On one hand, decision-making structures and processes must be clear and comprehensible. On the other hand, the decision-making process requires sufficient information i.e., full disclosure of research results or interim reports.

• Involving the population always leads to mostly unfounded panic. However, since we live in a democracy, this is important. More clarification would therefore be extremely important.
• Transparency of the process: very important, citizens often feel betrayed by business and politics.
• The highest priority should definitely be an objective (as far as possible) selection process that is not influenced by political disputes or money being passed back and forth in the background. The opinion of the citizens is undoubtedly important, but if it contradicts the apparently safest location, it should not be given much consideration in my opinion. In general, a transparent and transparent approach to this problem or task is important.

Fairness was mentioned directly by only 17 respondents. Indirectly, the need for a fair process and site selection procedure (i.e., procedural fairness) was frequently pointed out. However, the exact meaning of these statements is not always specified. Some links to the missing information were drawn from other subcategories related to the topic of fairness. This applies, for example, to the Transparency and Independence/neutrality subcategories from the Policy/procedure category. In general, a transparent, science-based procedure that aims to maximize the safety and protection of people and the environment is considered fair. It is often emphasized that the studies or explorations underlying the procedure should be carried out or at least be accompanied by independent scientists and neutral experts and should not be influenced by other actors such as politicians. The need for participation was mentioned in only four comments. Several respondents found it difficult to come across a solution that was appropriate or fair for all involved.

• The process should be accompanied by independent scientific experts and Non-Governmental Organizations.
• Overall, it is very difficult to find a fair solution for all people involved.
• We have to take responsibility for what we have done. If we produce nuclear waste in our region, we should also dispose of it fairly.
• What is important to me in such a process is fairness and transparency, a scientific basis and a well-founded exploration of all aspects (positive and negative).

Some respondents expressed concerns that the decision could be made for political motives instead of scientific criteria. Therefore, the importance of an objective scientific procedure (Independence/neutrality; n = 15) is often emphasized, from which politics and business should be excluded.

• Despite all the innovations in the procedure, I see a danger in past incidents that particularly—the so-called conservatives—will try to push through their political interests. If necessary, with the use of state violence.
• The problem with the whole thing is that politics interferes. If there were clear scientific criteria and politics had no say in the matter, then the procedure would be more logical and easier to follow, in my view. Science should have the final say and not politics or the citizens.

You should only let really absolutely competent people solve this problem, like scientists or geoseismologists… not politicians!

3.3. Risk/Safety

Data from comments on risks and safety are jointly presented and discussed, as there is a special relationship between these topics. Although various scientific definitions of risk exist, citizens are unfamiliar with risk as an academic concept. For them, risks should be avoided or—as they literally wrote—‘made safe’ (German: sicher machen). As stated earlier, the qualitative or bottom-up data show that respondents use the term safety to describe a default position or precondition for the acceptability of a technology: it must be safe (

Table 3. Categories of Risk and Safety.

Main Category	Subcategories	Frequency
Risk Addresses risks associated with final disposal	Other risks/hazards	44
	Health risks/environmental risks	23
	Uncontrollability/long-term consequences	18
	Radioactive leaks/radiation	12
	Transportation risks	2
Safety Addresses the issue of safety and control	Safety	158
	Control/monitoring	12

). In total, 158 respondents use safety in this manner (see the following paragraphs for a detailed analysis).

Other comments are unspecific and simply state that HLW is dangerous or that dangers (both terms are used mostly synonymously with risk by the respondents) could arise from an unsuitable location or from the facility’s technical imperfection (n = 44) without going into further detail.

• Nuclear waste is associated with danger.
• The dangers are unmistakable.
• I think it is far too dangerous to build such repositories close to society.

Risks were most often fairly abstract, such as risks to one’s health or the environment in general (n = 23). The terms human beings, health, nature/environment/biosphere, flora and fauna, and, in particular, future generations are usually mentioned as protected goods. The impending hazard is often described by the term infestation (German: Verseuchung), even though radiation risks have nothing to do with contagion. This may be due to historical reasons. The risks’ uncontrollability and possible long-term consequences for future generations are also frequently emphasized (n = 18). However, the discussion here is more about the dangers or burdens that people fear.

• I would think that a repository in my area would be very harmful to people’s health.
• High-level radioactive waste is dangerous. A good disposal place is hard to find because sooner or later, it will be a problem for the environment.

I find it fundamentally dangerous, I don’t have any children but I still care about future generations.

Few risks were explicitly mentioned in the comments; however, we further analyzed the safety subcategory (

Table 4. Subcategories of Safety.

Subcategory of Safety	Frequency
Safety as a must	51
Repository is not safe	38
Site selection	28
Uncertainty risk	15
Domestic safety	12
Other	11
Is safe	3

). We found that safety is indeed mainly used as a default condition (It must be safe; If it is safe, etc.; n = 51). Due to the factual necessity of a repository, which is admitted (albeit rather reluctantly), a large percentage of respondents emphasized the claim for a repository that is safe to the highest degree in the long term. Many respondents noted that a repository should be 100% safe or that it is most important that a repository should be safe. If the safe operation of a repository is proven, and if this proof is independent and fair, a considerable proportion of these respondents would accept a facility in their own neighborhood.

• The waste produced in Germany should also be stored here if a 100% safe location is found. Whereby I think it is unimportant in which region the repository is built. No matter where, the main thing is safety.
• My geology teacher always said that everyone wants wind power, but if you talk about building a wind turbine in the area, everyone is against it. And I think it’s pretty much the same with a repository. Of course, the thought of nuclear waste next to the house is not very pleasant, but we made the waste and now we are responsible for disposing of it. (…) So even if you are personally affected by it, you have to consider that it is—hopefully—the safest place to store the stuff, and therefore, you can pull yourself together a little bit for the good of the community and not act like a child.
• Safety is the most important thing. So the safest location must be chosen, even if the local residents are naturally against it. The common good comes first.

Other respondents reasoned that a repository cannot be safe per se or that there can never be 100% safety, especially in view of the long time periods (n = 38). Therefore, some emphasize that the site selection procedure must be designed in such a way that the safest possible site is found.

• What is certain is that nothing is certain. Only time will tell if the repositories are really safe to a high degree for the next years. And then it may be too late. I am not a paranoiac, but doubts remain about the safe final disposal of highly radioactive waste.
• There will never be 100% safety in nuclear waste and its storage.
• I don’t think there are any safe repositories for radioactive waste.

Despite this, surprisingly few respondents emphasized the importance of control or monitoring (Control/monitoring; n = 12; Table 3). The basic tenor is that “trust is good—control is better”; safe final disposal requires active human action to be aware of the processes and events in the repository and to take appropriate action if necessary.

• Whole continents have already broken up during such periods. Therefore, the retrievability and permanent monitoring of the repository must be guaranteed (…).
• German nuclear waste needs a German secure site that is not adjacent to a major city or municipality. It needs to be a no-entry zone for criminals and must be permanently monitored and controlled.
• Having the waste in your own country is much safer than abroad. Better control in the event of conflicts.

3.4. Trust/Distrust

The variable trust was coded under the main category Emotions (

Table 5. Category Emotions.

Main Category	Subcategories	Frequency
Emotions Addresses various emotional dimensions associated with final disposal	Fear/anxiety/discomfort	65
	Acceptance	58
	Trust (partly indignation and distrust)	41
	Quality of life	4
	Burden	1

), following the categorization by Stefanelli et al. [24].

Emotions linked to a potential repository for HLW planned in the respondents’ vicinity were mostly negative (Fear/anxiety/discomfort; n = 65). Nevertheless, trust also plays a central role, as indicated by a relatively high number of comments (n = 41), but mainly as distrust or doubt that institutions, politicians, or companies can be trusted. The lack of trust is often justified by referring to negative examples, such as the leakage in the Asse II mine (The Asse II mine is a former salt mine in which intermediate- and low-level waste has been stored since the 1960s. Due to the instabilities of the mine and increased public awareness, work is now underway to retrieve this waste (https://www.bge.de/en/asse/ (accessed on 23 May 2025)) in northern Germany, which poses risks to the waste stored there (and why it is planned to retrieve the casks).

• Since the population is not asked anyway and we are permanently told lies by the politicians, I do not trust the institutions at all.
• My trust in careful final disposal has been damaged by the events in the Asse repository.
• I am against this in principle because I have no trust in the institutions.

However, there are many respondents who are convinced of the proper disposal of HLW. This often originates in a high level of confidence in the competence and expertise of German engineers, scientists, or political decision-makers. Frequently, references are made to the expertise available in Germany that is, expressed as confidence in the technical feasibility of building and operating a repository. Nevertheless, some respondents who state such a view still feel uneasy.

• It will be very difficult to find a suitable location. Nevertheless, we have to face this challenge. I have complete faith in today’s science, which will work out a fair and acceptable solution, together with the political decision makers and the stakeholders, [regarding] the future site.
• If it were decided that the best option would be to set up a repository in my region, I would fully support this decision. I think it is hypocritical to call for a repository, but please not at my home, but somewhere else. Of course, I would also be concerned about the possible consequences/impact that such a repository would have on my life or that of future generations, but we must also show solidarity so that these concerns apply to all people, regardless of the location of the repository.

4. Discussion

In this paper, we present an independent qualitative analysis of an otherwise quantitative survey conducted in 2020 (n = 4690) on the topic of the final disposal of HLW. Overall, we gathered 1894 usable comments covering a broad range of topics. The fact that 56% did not avail themselves of the opportunity to write their comments probably has several causes. For example, we know from other studies that certain topics, such as the final disposal of HLW, tend to be of little interest to large sections of society as long as they are distant in time and space [44,45]. However, almost half of the original sample did comment in some way, perhaps because it is an emotional and controversial topic, even if it is not yet that relevant to the majority.

Through this study, we learned about potentially important contexts explaining trust and acceptance of the site selection procedure and a possible final repository. The qualitative results paint a picture of the German public’s current discourse on HLW management, with the respondents occasionally expressing contradicting ideas about what is necessary or possible to solve the problem of HLW disposal. In this study, we linked the aforementioned topics to current scientific discourses. For example, ethical–moral aspects, such as responsibility, procedural or distributive justice, and risks to future generations, are repeatedly discussed [46,47].

In contrast, it is extremely difficult for respondents to assess the technical safety of a repository or to evaluate the risks in detail. For example, risks during transportation (because of blockades and unnecessarily long and high exposure of mainly police forces) or repackaging are assumed to be important risks by experts but are almost absent from the comments. Nonetheless, the data indicate a strong agreement between respondents’ opinions on HLW management and the current state of science and technology. The few counterexamples include that HLW could easily be shot into the sun or rendered harmless in a short time by already available advanced technology (e.g., the current possibilities of transmutation and partitioning are overestimated [48,49]). Our data show the large role of values among respondents’ opinions in evaluating the topic and its facets. The results corroborate earlier assumptions and results from a bottom-up perspective. Values have been shown to be related to risk perception, trust, and acceptance of (nuclear) risks [41,48,50,51].

The literature frequently points out the normative necessity of procedural fairness in the selection of a suitable site for an HLW repository [42,46] as it does for the siting of landfills in general [49]. Interestingly, only 17 respondents used the terms “fair” or “fairness” in their comments. However, many other comments in other subcategories were related to the category Politics/procedure. They point out which aspects of a site-selection procedure are considered fair or unfair. These comments repeatedly indicate conditional aspects in terms of a fair procedure. Moreover, there is a close connection between the perceived fairness of a procedure and the topic of trust. For many respondents, a trustworthy procedure includes sufficient information and transparency on both procedural and communicative levels, as well as sufficient information provided to the concerned communities. All of the mentioned aspects can basically be assigned to the six criteria for procedural justice developed by Leventhal [52], as quoted in Tyler [53] (p. 105), specifically “consistency, the ability to suppress bias, decision quality or accuracy, correctability, representation, and ethicality”.

Additionally, the independence and neutrality of the procedure and decision-makers should be guaranteed, according to the respondents. External influence by special interest groups or through lobbying (see category Economy/lobbyism and the Supplementary Table S1) undermines the perceived fairness of, the trust in, and ultimately the acceptance of the whole procedure (e.g., those who do not expect a fair site selection procedure do not report trust in politics or in the rule of law in general). For this reason, many respondents stressed that the scientific nature of the approach is essential to ensure the safety and health of the population. This request can be answered by referring to the safety case introduced above. A relatively small number of experts have developed this concept [54], which seems to be practically unknown to the majority of citizens. Earle et al.’s [55] finding is confirmed that the public’s perceived similarity between their values and those upheld by scientists increases the former’s trust in the latter (as opposed to perceptions of politicians). We also know from another study that “respondents trusted some sources of scientific information about the environment considerably more than they trusted other sources” [56] (p. 129). In general, other studies have repeatedly found that trust in science is highest [28,57], while trust in the government is low [58].

Our data show that judging the site selection procedure as fair increases people’s trust in the responsible actors and, ultimately, the acceptance of the procedure. This finding is corroborated by a study by Besley [59] (p. 271) on a public participation process related to nuclear energy, concluding that “those who believe a procedure is fair are willing to accept a decision”. That aspects such as procedural fairness, but also safety, burden sharing or mistrust of the government “influence the formation of opinions regarding final disposal policy” has also been shown in a recent study by [58] (p. 830). As with other aspects of sustainability, it appears that in the area of HLW disposal, “ignoring or marginalizing locally held values in the design and implementation of (…) programs can leave a legacy of mistrust and create conflicts with local communities” [7] (p. 818).

Contrary to expectations, a very low number of respondents named citizen participation as a possible element of procedural fairness. We attribute this finding to the low number of respondents who were concerned at this early stage of the site selection procedure. Citizens may not currently fear threats to their values. This is in line with the results obtained by Siegrist, Connor, and Keller (2012), who studied opinions on gene technology [60]. They state “that the impact of procedural fairness on the acceptance of field experiments is larger for people for whom gene technology is a morally relevant issue,” while “the impact of outcome fairness on acceptance is higher when moral conviction about gene technology is low (e.g., gene technology does not threaten important values)” [57] (pp. 1400–1401). Presumably, the perceived demand for participation will increase as the procedure progresses. However, we cannot make an empirically substantiated statement about this at present. Other studies also indicate that the degree of cooperation with stakeholders is an important factor influencing the siting and construction of a HLW repository [17].

What is said about fairness applies similarly to the value of safety. Many respondents noted that the repository must be safe or that Germans need a safe repository; some even demanded 100% safety. However, it seems insufficient to ask only about the importance of values, as most value studies do, because many respondents make conditional judgments, such as “If a repository can be operated in the safest way in my region, then I can accept it.” The question here is whether a value that has been individually identified as important is being violated. Push-and-pull factors may be at work in the preceding example. On the one hand, the respondents want the repository to be safe, in which case they would agree (conditional push). On the other hand, they are pulled because if it was safe, they would have to live with it (conditional pull). However, few comments have defined safety in an exact way. The term safety denotes the absence of risk, harm, or danger [61,62]. Moreover, certain important values that should not be violated at all are named in this context. For example, a safe repository should not have a negative impact on nature, the environment, or the health of present and future generations. Meanwhile, specific risks, such as the carcinogenic effects of ionizing radiation, were not mentioned. This result is in line with other studies in which the main concern of the respondents is the impact of radioactive waste on the population, citizens, and the environment [17] (p. 14). The statements on the consideration of future generations are noteworthy for their inclusion of the intergenerational dimension, which aligns them with scientific discourse on sustainability. We agree with Kermisch and Taebi [27], who argue that the concept of sustainability could be used as a moral framework, for example, to undertake “an in-depth analysis of values associated with different options for nuclear energy production and for nuclear waste management”. This would help “to account for intragenerational conflicts as well as for intergenerational ones, insofar as the framework is able to highlight the fact that a technology might be sustainable with respect to some values or to some groups, whereas it might be unsustainable with respect to other values or to other groups that are spatially or temporally distant. However, even though the framework is helpful for highlighting value conflicts, it does not solve these conflicts” [27]. It should have become clear that a sustainable HLW management process requires consideration of values. In this regard, Törnblom et al. [6] developed a framework that recognizes the interrelationships between values (e.g., moral and ethical values of those affected) and the concept of sustainability. Their 31 factors (e.g., 12. Distributive justice principle, 13. Procedural justice principle) “may be used to analyze the sustainability and justice of a situation or a project already in place, or to asses a project that is not yet implemented with the aim of optimizing the just-sustainability and sustainable-justice of the outcomes” [6] (p. 1).

We would like to point out that the above-mentioned views refer, of course, to the general, still rather abstract situation of current efforts regarding HLW disposal in Germany. The situation would be different if one or more local sites were selected [63,64]. Nevertheless, the aim of waste management organizations is “to identify specific tasks and develop appropriate strategies and measures for a sustainable design for the implementation of the deep geological disposal of radioactive waste” [2] (p. 7). Without knowing the exact modalities of the procedure and the main actors involved, it seems difficult to comment on the procedure, criticize it, or offer constructive suggestions for its improvement. Furthermore, the opportunity to comment was not linked to specific research questions. This is due to our methodological rationale that there is no large-scale bottom-up study that shows how the public currently perceives the issue. In addition, we only reached people who met the technical and personal requirements to participate in an online survey.

The same issues were frequently mentioned in the comments across all demographic groups. These reflect the known differences between men and women in terms of negative emotions and risk perception [60,65]. Although interesting, this matter is not the focus of our study. Less often, the respondents explicitly differentiated between the disposal problem in general and the site selection procedure in particular. A potential limitation of this study is that respondents may have been influenced by the questionnaire items before formulating their comments. However, this is contradicted by the fact that although five specific risks and benefits were listed for each of the consent ratings, respondents rarely mentioned them. Benefits were almost never mentioned. Another limitation is the self-selection of respondents who provided comments. As a result, the intended representativeness was slightly impaired, albeit only to a small extent.

5. Conclusions

One implication of our current study is that future studies should consider value-related issues not only in terms of how important someone judges value x but also in terms of advocacy or fulfillment according to individual standards. As we have illustrated, this conclusion holds true for fairness issues and the value of safety in HLW disposal. However, when is a procedure judged to be safe and fair enough—and by whom? There are no general answers to these questions, but this operationalization challenge should be considered in future surveys. More in-depth qualitative studies are necessary to clarify this point.

Therefore, we would like to point to the research approach itself. In the past, we used precast risk and benefit items to measure risk perception on a Likert scale. The items were developed based on earlier hands-on experience with the local public. However, as our recent bottom-up research in Germany shows, respondents rarely mention specific risks and almost never mention positive aspects related to a repository. Therefore, we encourage ourselves and our colleagues in risk research to occasionally revisit the assumptions about how to measure risk perception. The bottom-up approach provided differentiated indications of context, societal lines of argumentation, and patterns of interpretation that we can take into account in future surveys. This may have a positive impact on further theory development and empirical studies and, thus, on decision-making.

Finally, it has been shown that when communicating with the public, one may refrain from focusing on the technical risk concept, which contains various definitions and can lead to complex discussions on, e.g., probabilities. This does not mean concealing a repository’s risk issues, thus violating the golden rule of fair procedure. However, the results show that the respondents hardly mentioned risks but rather talked about hazards or safety. Concrete risks that are actually associated with HLW disposal are almost not mentioned at all in the comments, although they were evaluated by the respondents shortly before in the questionnaire (e.g., transportation risks). Obviously, the respondents were not too much influenced by these survey items. The topic seems far from the reality of the lives of the vast majority of people. It cannot be assumed that the general public is familiar with detailed issues of final disposal. We believe that bottom-up approaches are significant because they are closely aligned with people’s motivations. The ability to precisely comprehend the issues, concerns, and potential fears driving public discourse is anticipated to be of significant benefit to communication efforts. Addressing the socio-cultural constructions of risk, which encompass the potential infringement of social values, is imperative. The study shows that it is essential to prioritize the protection of both intangible and tangible values, like the natural environment, the reputation and development of the home region, or public health, particularly with regard to future generations. These values must be addressed and resolved. The often-heard accusation of political influence or hidden agendas can probably also be refuted by the fact that local stakeholders are given certain participation rights within the framework of stakeholder involvement, which is possible within the political system. Bottom-up studies can also be useful for authorities in communicating with the public as a reference and for argumentation support. In this sense, they can provide authorities with a basis for taking the public’s values into account. This is particularly true for regions that will be in the focus of the siting procedure in the future.