Eckard Rehbinder

Radiation risk and radiological protection

With respect to radioactive waste health risks are caused by ionising radiations which occur in conjunction with the decay of radionuclides. Biological risks of ionising radiation were already identified a few years after the discovery of X-rays by Rontgen (1895) and of radioactivity by Becquerel (1896). A very extensive knowledge has been achieved about estimating radiation doses (see section B 2.2) and radiation effects by clinical studies as well as by experimental investigations. For risk evaluations, the shape of the dose effect curves is of eminent significance (Fig. B.29). In radiation research as well as in toxicology of chemicals in general two principal categories of dose effect relationships have been described (ICRP 1977). The shape of these dose response curves is based on manifold experimental studies of radiation effects which have been experimentally investigated by studying molecular structures, living cells and animals after radiation exposures. Further data have been obtained from clinical experiences and epidemiological studies which have been observed after the exposure to ionising radiation in humans in connection with radiotherapy, diagnostics, atomic bomb explosions in Japan and further accidents (UNSCEAR 1993; 1994; 2000; 2006 BEIR 1990; 2005).

Schlussfolgerungen und Empfehlungen

Verpflichtungen, die den Akteuren eine umsichtige Entsorgung radioaktiver Abfalle auferlegen, gelten prinzipiell unbefristet und bestehen – wenn auch in ihrer Verbindlichkeit graduell abnehmend – auch gegenuber den Angehorigen ferner Generationen. Die bei der Entwicklung von Entsorgungsstrategien einzubeziehenden komplexen Verlaufe (die “Folgenraume”) sind gleichwohl aus rationalen Erfordernissen der Planung und aus Grunden der Effizienz zeitlich zu befristen. Eine solche Befristung sollte sich am voraussehbaren kunftigen Wirkungspotential der Folgen orientieren, und damit am relativen, mit den Phasen des Zerfalls-Prozesses und der gewahlten Entsorgungsstrategie variierenden Gefahrdungspotential der Lagerinventare und moglicher Expositionen in der Biosphare.

Guidlines for a socially acceptable and fair site selection

The process of selecting a site for the final disposal of high-level radioactive waste is an issue which has fuelled extremely heated debates in Germany ever since the commissioning of the Kahl nuclear power plant, Germany’s first experimental plant, in 1960. For forty years now, representatives of a wide variety of interest groups, such as civil movements, ecological groups, as well as representatives from the world of science, politics and industry have tried to agree on a mutually acceptable concept for the selection of the site for the final disposal of high-level radioactive waste. There are manifold reasons why no agreement has been reached to date and why the conflict remains unresolved – and they are not least rooted in the nature of the issue itself (Hocke/Renn 2009). This chapter first takes stock of the perception of the final nuclear waste disposal problem, continues with a conflict diagnosis and concludes with a discussion of the various options for dealing with this conflict.

Annex 2: Legal questions – comparative experience in selected countries

The following chapter compares in greater detail the regulatory experience important nuclear countries have made in managing high level nuclear waste. It encompasses the United States, France, the United Kingdom, Switzerland, Sweden, Finland, Japan and Spain. The structure of the presentation corresponds to that of the analysis of German law in chapter 4 so as to facilitate the comparison between the respective countries as well as with Germany for the reader.

Management of high level radioactive waste with reference to long-term responsibility

Judging by the prolonged protests and debates in Germany and other countries over the management of radioactive waste, the issue of finding an adequate waste management strategy seems to be afflicted with a considerable potential for conflict. The easily raised tempers and the emphasis and passion with which arguments are put forward are just an external indicator of this – and not a particularly reliable one. Clearly, the heated mode in which the conflict is sometimes carried on in public is a characteristic trait of the debate and deserves closer attention, especially if one is interested not only in the theoretical development of strategies, but in the practical resolution of the conflict. And if a solution is to be brought about by resolving factual issues rather than issues of power, the conflict must also be analysed in terms of its social and political dimensions, in order to test how the partisan insistence on a particular position can be transformed into a constructive discourse about rational strategies acceptable to all parties (see below, section B 3.3). This is the only way to find a legitimate as well as legitimized solution.

Legal questions of managing high level radioactive waste

In the 1980s, there was a controversial debate in Germany about the constitutionality of the peaceful use of nuclear energy which also addressed the problem of radioactive waste disposal. Hasso Hofmann, a specialist of constitutional law and philosophy of law with high reputation, took the position that the use of nuclear energy was ethically irresponsible and unlawful from a constitutional law point of view (Hofmann 1981:286), relying to a major degree on arguments related to the problem of final disposal of high level radioactive waste. Hasso Hofmann was particularly concerned about the fact that, due to the long half-time of high level nuclear wastes, these wastes had to be deposited under strictly controlled conditions over a period of time the dimensions of which exceed human imagination, at least human calculation. Leaving such a nuclear legacy to hundred thousands of future generations whose needs, values, technological capabilities and political-administrative governance structures could not be predicted, was in Hasso Hofmann’s eyes ethically irresponsible and unconstitutional. Therefore he strongly pleaded for abandoning the use of nuclear energy. Other authors50 strongly opposed this view, arguing that the waste problem was technically and socially manageable.

Annex 1: Some fundamental data for the assessment of radiation risk and radiological protection

For the estimation of radiation risk the assessment of the radiation dose and the knowledge of the dose response for certain radiation effects are necessary. The basic quantity for the radiation dose is the absorbed dose, D, given in Gy, which can be measured exactly by physical means. For radiological protection the absorbed dose is averaged over a whole organ or tissue and then the dose conversion factors can be evaluated from measurements of external radiation fields in specific organs and tissues. For internal exposures the incorporated radionuclides have to be determined by either whole body counters or scintillation counters or measurements of radioactivity in the blood, faeces or urine. Dose coefficients for the organs and tissues can then be calculated with the help of biokinetic models. By these procedures the absorbed dose DT, R is determined in an organ or tissue (T) for the radiation (R).

Waste management strategies and disposal design

A solution to the problem of long-term radioactive waste management (RWM) comprises a technical and social dimension, i. e. it must not only be technically achievable, but also publicly acceptable. The technical solutions have to demonstrate beyond reasonable doubt that a method/concept exists to ensure safe and secure containment of long-lived highly radioactive waste for the indefinite/distant future and that undue burdens on future generations are avoided (taken from Flowers Report (Flowers 1976) but modified).

Methodische Grundlagen der Festlegung von Umweltstandards

Unter „ Umweltstandards“ werden im folgenden quantitative Konkretisierungen von Umweltqualitatszielen verstanden; sie sind Mittel zu deren Erreichung. Umweltqualitatsziele sind Satze, durch die normative Vorstellungen hinsichtlich der Qualitat der Umwelt des Menschen oder anderer Lebewesen zum Ausdruck gebracht werden. In Umweltqualitatszielen kondensieren sich gewissermasen die umweltpolitischen Leitvorstellungen hinsichtlich der Anforderungen an die Umwelt (en) unter allgemeinen Zwecksetzungen wie Gesundheit, Nachhaltigkeit, Systemfunktionalitat u.a.7 Mit Umweltstandards kann man sich aus unterschiedlichen Interessen befassen, die sich grob in deskriptive und praskriptive einteilen lassen.

Beurteilung und Empfehlungen

Umweltstandards sollen Mittel zur Vermeidung schadlicher Wirkungen von Noxen sein. Der uberwiegende Teil der Umweltstandards ist bisher fur Einzelexpositionen festgelegt, nur in wenigen Fallen sind Zweifach- oder Mehrfach-Expositionen berucksichtigt worden. Kombinierte Expositionen erhohen die Komplexitat bei der Beurteilung von Schadwirkungen. Daher bedarf dieses Problem einer besonderen Betrachtung.