What does it mean, "final disposal"? Radioactive waste generated at each stage of the so-called nuclear fuel cycle is a problem for many reasons: Firstly, it is highly radiotoxic. Plants, animals and human beings must be protected against the harmful effects of ionizing radiation. Secondly, many radioactive substances are extremely "long-living", their physical half-life ranges up to tens of thousands years or even billions of years. This means very long periods of hazardousness and, consequently, the need for very long isolation times from the biosphere. Let me illustrate this issue by showing you the time required for the decay of radionuclides, compared with historical and geological periods:
We start in our time at 1982. . . . On the left-hand side we are looking into the past; please note the logarithmic scale . . . . About 100 years ago, beginnings of industrial underground mining in Europe; about 500 years ago, Europe discovered America; and Iron Age, Bronze Age; about 10,000 years ago, the last glacial period ended, e.g. here in Salzburg, Wuerm glaciation. About 100,000 years ago, the Neanderthal Man lived on earth; and about one million years ago, the first beings appeared on our earth.
On the right-hand side we see the time required for the decay of radionuclides. It is a rough illustration only and distinguishes between three phases: Firstly, the phase of fission products like strontium or cesium which require some thousand years to decay totally. Second phase: phase of actinides like plutonium or neptunium which are toxic for several thousands of thousands of years. And the phase of decay products -- that means e.g. daughters of uranium like radium -- they are relevant for millions and millions of years.
As I said, this is a very rough classification only; in fact, many radionuclides cover the whole time scale, e.g. iodine-129. It is a fission product of great significance because it is very mobile in the deep underground and in the biosphere. It is harmful because it accumulates in the thyroid where it can cause cancer. Its half-life is about 17 millions of years -- a look at our figure shows that 17 million years ago not even human beings existed on earth!

Thank you very much. We would say in Kenya "Kariboni" -- welcome! And "Habarigani" -- good morning! I welcome you for the Day of the Deserts, and we won't waste a minute to welcome our guest speaker this morning to open our day. Miss Fink from Germany is going to speak and her theme is "Concept for a Radioactive Future"; so welcome!

The Nuclear Guardianship
Concept for a Radioactive Future

Lecture by Ulrike Fink

Ulrike Fink, Fed. Rep. of Germany. Biologist,
member of the Group Ecology, Hannover.

My lecture deals with the unresolved problems of final disposal of atomic waste. And I'll speak from my particular German point of view. Although there are different approaches to the problem in different countries, Germany may serve as a good example to show which concepts have been developed by government and related scientists of a rich, capitalistic country and in which way their attitude changed with time due to several difficulties. Another preliminary remark: It is a frightening fact that not only in the early years of using atomic power but even today -- as we have heard during the last two days -- that even today rad waste was and is simply dumped into the environment or stored insufficiently and thus pollutes the lakes, the oceans, the rivers, the air, and the land.

To begin with, I'll give you a short illustration of the situation in Germany. Nuclear power plants have been in operation since the early seventies, and nowadays 21 nuclear power plants produce more than 30 percent of the country's electric power. The uranium ore is coming from Australia, Namibia, Canada and so on, that means, the enormous wastes and environmental pollution connected with this is far away from our country and thus, we normally don't become aware of it. The German government has decided that reprocessing of spent fuel is the way of getting rid of the problem with waste -- surely the least suitable way, because this not only leads to severe radioactive pollution of the environment -- think of the Irish Sea or the English Channel -- but moreover, reprocessing leads to a considerable increase of waste. According to current plans, the final disposal of radioactive waste is -- or will be -- done in Germany, in fact in deep geological formations.

What does it mean, "final disposal"? Radioactive waste generated at each stage of the so-called nuclear fuel cycle is a problem for many reasons: Firstly, it is highly radiotoxic. Plants, animals and human beings must be protected against the harmful effects of ionizing radiation. Secondly, many radioactive substances are extremely "long-living", their physical half-life ranges up to tens of thousands years or even billions of years. This means very long periods of hazardousness and, consequently, the need for very long isolation times from the biosphere. Let me illustrate this issue by showing you the time required for the decay of radionuclides, compared with historical and geological periods:

We start in our time at 1982. -- It's a funny thing with people's mental images concerning time: When I looked for a suitable graph to illustrate the required isolation time and found this one, I certainly realized that this date is not correct and, you may believe it or not, for one moment I reflected on updating it. Only on second thought it became evident to me that ten years doesn't matter at all, considering the long, eternal time of interest.

On the left-hand side we are looking into the past; please note the logarithmic scale: That means 100 years, 1,000, 10,000 and so on. About 100 years ago, beginnings of industrial underground mining in Europe; about 500 years ago, Europe discovered America; and Iron Age, Bronze Age; about 10,000 years ago, the last glacial period ended, e.g. here in Salzburg, Wuerm glaciation. About 100,000 years ago, the Neanderthal Man lived on earth; and about one million years ago, the first beings appeared on our earth.

On the right-hand side we see the time required for the decay of radionuclides. It is a rough illustration only and distinguishes between three phases: Firstly, the phase of fission products like strontium or cesium which require some thousand years to decay totally. Second phase: phase of actinides like plutonium or neptunium which are toxic for several thousands of thousands of years. And the phase of decay products -- that means e.g. daughters of uranium like radium -- they are relevant for millions and millions of years.

As I said, this is a very rough classification only; in fact, many radionuclides cover the whole time scale, e.g. iodine-129. It is a fission product of great significance because it is very mobile in the deep underground and in the biosphere. It is harmful because it accumulates in the thyroid where it can cause cancer. Its half-life is about 17 millions of years -- a look at our figure shows that 17 million years ago not even human beings existed on earth!

The third problem connected with rad waste concerns the aspect of the amounts. The amounts have considerably increased since the early years of nuclear power use and increases daily. This is relevant because if you deal with minor amounts only, you can -- if you will -- you can use sophisticated and expensive methods, e.g. utilize waste canisters made of copper -- a few centimeters thick -- which are resistant to corrosion for maybe hundred of thousands of years. And -- another aspect -- the number of sites which might be suitable for waste disposal is limited.

This leads to the question: In what way can the long-term safe isolation of rad waste from the biosphere be achieved? The answer which was given by governments and think tanks is: Final disposal in the deep underground. The reason for this is evident: Movement of materials in deep geological formations is, in general, essentially slower than at the surface of the earth or in oceans. This gives rise to another question: How can evidence of the long-term safe behaviour be given? Surely, an absolute proof is impossible. "What must be achieved" -- I quote from a recently published brochure -- "what must be achieved is a convincing and indirect demonstration that the proposed disposal system provides a sufficient level of safety to both current and future generations." Aha. O.K., let's have a look into this strange theoretical world.

How can the long-term, that means, eternal safety be demonstrated? The problems connected with this question are quite novel, because the purpose of final disposal in the deep underground is and must be to store the waste definitely and eternally. That means, it is not intended to retrieve the waste in the near or in the far future. To my opinion, this makes sense because retrieval is impossible and dangerous: Firstly, because of the so-called convergence -- that means the rock or the salt in which the waste is disposed creeps together, it closes the hollow spaces. This is not a long-lasting process at all: In a salt dome, for example, the gallery will close during one or two generations of miners. Thus, you can't retrieve the waste packages without destroying them a few decades after disposal. The second reason for me is that it's not possible to pass on the knowledge about the hazardous materials hidden in the ground to future generations -- you can't ensure that they will keep the information or make use of it. Let me give two examples: The Ruhrgebiet is a region in Germany where intensive coal-mining has been performed for more than 100 years. Everyone knows that Germans are especially tidy and painstaking -- but nevertheless, now and then it happens that old pits of abandoned coal mines are just drilled by chance! That means, either the knowledge has got lost during 100 years or the people didn't study the available, existing data -- the people were not conscious of the problem.

My second example gives rise to the speculation that data losses nowadays may take place even faster due to the rapid progress and subsequent incompatibility of computer systems: Data files stored 20 years ago on magnetic tapes can't be read by modern computers anymore! Nevertheless, the problem of passing on the information is significant in another context -- that is, how to ensure that future generations do not penetrate into the repository accidentally, e.g. by drilling in the underground or by blasting operations. This problem has been discussed a little bit, and some suggestions have been made, like creating taboo areas, like establishing a nuclear priesthood, or by setting "land-marks", e.g. like the Egyptian pyramids. To my opinion, none of these suggestions is -- once realized -- able to ensure that the knowledge is passed on to future generations or -- what might be even more important -- that future generations make use of the information.

To come back to the problem of long-term safety: What I said leads to the conclusion: It is necessary to select a site in the most careful and painstaking way. It must be demonstrated in advance that the radionuclides will be retained for very long periods and that no harmful releases of radioactive substances are likely to occur, because you cannot make experiments; you can't make inspections or controls of a closed repository; and you can't "repair" any errors. The "solution" to this problem provided by the experts is the so-called "safety assessment". This is a method to describe the future behaviour of the waste disposal-site and of its potential impacts on humans and the environment. In Germany, long-term safety assessments are performed by a "safety analysis" in the following manner: It is assumed that the closed-down repository will be flooded, that means it is filled up with deep groundwater. The radionuclides are released and dispersed inside the mine and afterwards inside the deep underground, and this will probably require a long, long time -- if nothing unexpected occurs. Finally, the release leads to the pollution of underground water near the surface which is used by human beings. People will drink the water, irrigate their fields with it and so on. The radiation dose resulting from this is calculated and the results are compared with current dose limits -- that is 30 millirem per year in Germany.

This is the moment of decision: If the calculated dose is below the limit, the proposed waste disposal can be considered safe enough in the long term. If the dose is above the limit -- no, not what you might think after my presentation of this wonderful theoretic concept -- if the dose is above the limit, it does not mean that the site is not suitable, but the modelling and calculation has to be performed once more by using different input data or methods. It is evident that this procedure is very problematical, because it requires mathematical descriptions and long-term predictions of the behaviour of complex geological and other systems. This leads to results which are largely speculative -- they can mean anything and nothing.

What I told you up to now has been the theoretical approach. Now let's look at the reality, how decisions for disposal sites have been made in Germany and in what way decisions were put into practice. Let's come back to our map: In Germany, there has never been a systematical search for disposal sites. Indeed, in the mid-seventies, investigations of three or four salt domes in Lower Saxony -- in my country -- were started, amongst them Gorleben, but the investigations were broken off for reasons which have never been disclosed really. They chose just Gorleben -- a site which was given no chance by the experts before -- due to its location at the former German/German border, i.e. the eastern part of the saltdome could not be investigated. That's it. Gorleben was not chosen as the best potentially available site, but for political reasons! The saltdome has been investigated for about 14 years to see whether it might be suitable or not for the final disposal of all rad wastes, including spent reactor fuel. It's curious: The more they investigate the more it becomes obvious that Gorleben is not suitable at all. Under normal circumstances, this would lead to giving-up -- but not in this case.

Another example is Morsleben. Morsleben is a repository in operation. It's an abandoned salt mine and a heritage of the former GDR (East Germany). They chose it because it was located near the former German/German border, a region of particular secrecy. Of course, no long-term safety analysis has been made prior to the storage. To our opinion, Morsleben is not safe at all, not only concerning -- what I've been talking about -- the long-term safety but even the near future safety. But, according to the German Federal Government and its related scientists, the Reactor Safety Commission, the repository is safe until 30 July, 2000. The reason for this peculiar date is a legal one. Thus, they are -- as they say -- luckily obliged to dispose of rad waste into Morsleben.

My last example -- what's the nearest to my heart -- the last example is Konrad. Konrad is a former iron mine situated in the city of Salzgitter. When the mine was abandoned in the mid-seventies, the Workers' Union thought it would be a good place for a deep underground repository, and the site has been investigated since then. Ten years ago an application was made. It is planned to store more than 95 percent of the total waste volume arising in Germany in Konrad. Konrad may serve as a good example to show how safety requirements have been changed or even given up in the moment when difficulties arise -- and I tell you, they arise everywhere.

I told you about the German approach to evaluate long-term safety. Remember the safety analysis. Originally, the time period for the described analysis was not restricted. This has changed a few years ago when the experts became more and more aware of the impossibility to predict the behaviour of radionuclides in the far future and when they realized that -- using this approach, Konrad -- the radiation exposure would exceed the given standards. Without discussing this in a broad scientific or co-operative way, a small group arrogantly decided what to do: The official Reactor Safety Commission decided that the procedure should be applied to a period of 10,000 years only; afterwards, for longer periods of time, long-term safety should be judged by another criterion which unfortunately is not fulfilled by Konrad. Anyway, at the moment Konrad is the focus of national attention: Last year, the so-called "Plan", i.e. the official information about the project, has been made public, and about 289,000 people have objected against the project. The public inquiry is scheduled for the 25th September and it will be held in Salzgitter. It is expected to run for several weeks. I hope to see again some of you in Salzgitter next week or a little bit later.

I come to an end now. Final disposal of radioactive waste is only one part of the dirty and pollutant so-called nuclear fuel cycle, but an important one because future generations will be affected. What I wanted to show is: It is impossible to ensure that the safety of future generations can be guaranteed; even using the now available most sophisticated methods. Moreover, experience shows that decisions for repository sites are scarcely based on pure scientific demands -- not to mention ethical demands -, they are made for political reasons, and the requirements are simply changed or even given up in the moment when difficulties arise. This leads me to the conclusion that an immediate stop of the use of nuclear power is necessary, just to slow down the further pollution of our earth.

That's all. Thank you for listening.