Nuclear power and the Second Law
A nuclear reactor is not a stand-alone system: nuclear power is only possible by means of a sequence of conventional industrial processes [more i12]. As any process are these nuclear-related processes amenable to the Second Law. As a consequence releases of all chemicals involved in these industrial processes into the environment are unavoidable. No chemical plant can be leak-proof.
The nuclear reactor is the only part of the nuclear system that does not emit CO2, all other parts do. The CO2 originates from the combustion of fossil fuels to power the industrial processes and from chemical reactions, for example the production of concrete and of steel from iron ore. The specific CO2 emissions of the nuclear chain are rising and will surpass that of fossil fuels within the lifetime of new nuclear build. The rise is caused by the decreasing thermodynamical quality of the yet available uranium resources over time, which in turn is a consequence of the Second Law [more i05, i38]
In the front-end processes, the production of enriched nuclear fuel from uranium ore, massive amounts of fluorine and chlorine and their compounds are consumed [more i07, i13]. The most potent greenhouse gases known are compounds of fluorine and chlorine. Emissions of potent greenhouse gases by the nuclear energy seem not only possible, but seem likely. Emissions of greenhouse gases and releases of other chemical pollution by nuclear-related industries are a well-kept secret. No published data does not equal 'no emission'.
Self-evidently radioactive substances are also chemical substances,the only difference with common chemicals is the presence of radioactive isotopes. Radioactive and non-radioactive isotopes are chemically identical. As pointed out above massive amounts of chemicals are being used in the nuclear process chain [more i13]. Inevitably a fraction of these chemicals are discharged into the environment, as a consequence of the Second Law, and with these sunstances radioactivity is being released into the environment.
In the nuclear energy system massive amounts of radioactivity are mobilized and generated [more i08], starting with the extraction of uranium from the earthÕs crust. The natural radioactivity, which in itself is far from harmless, is in the reactor multiplied with a factor billion. An appreciable part of this human-made radioactivity is released into the environment, partly intentionally, partly due to technical imperfections and sometimes as a result of accidents. In all cases the Second Law is playing an important role. The chance of large accidents increases with time, due to deteriorating storage containers and facilities, a direct consequence of the Second Law.
Radioactive emissions are generally concealed, or are played down as 'harmless' by the nuclear industry and associated institutions if disclosed nevertheless. Even emissions of radioactive materials classified as 'weakly' radiotoxic turn out to be harmful for people living in the neighbourhood of nuclear power stations. Not to speak of the massive radioactive contaminations after large accidents, such as Chernobyl and Fukushima [more i21].
Thermodynamic quality of uranium ores
Uranium-bearing rocks, in some cases called uranium ores, are present in the earthÕs crust in different appearances and at widely different properties. Rocks with the highest content of uranium are the rarest, rocks with lower contents are much more widespread. This common geologic phenomenon, valid for almost all metals in the crust, results in a well-known distribution of the uranium resources: more uranium is present the lower its content in geologic formations. This grade distrbution is in itself a consequence of the Second Law during the history of the rock forming.
From the Second Law follows that the energy investment per mass unit of extracted uranium increases exponentially with declining ore grade of the deposits from which the uranium is extracted: the energy cliff [more i38].
Separation processes play a vital role in the nuclear energy system, in the once-through mode and the more so in an envisioned closed-cycle mode. Separation processes are governed by the Second Law. As separation processes never go to completion, it is impossible to separate a mixture of different chemical species into separate fractions without losses [more i42].
Extraction of uranium
The nuclear process chain starts with the extraction of uranium from its ore, by means of a sequence of physical and chemical separation processes. As a consequence of the inherent limitations of separation processes the extraction of uranium from uranium-bearing rock consumes more energy per kilogram recovered uranium and goes less completely with decreasing ore grade. This phenomenon comes on top of the dilution factor. Jointly both factors are the cause of the energy cliff [more i38 and i42].
Reprocessing of spent nuclear fuel is a pivotal process in a number of advanced nuclear concepts. Separation of highly radioactive mixtures, containing dozens of radionuclides, into 100% pure fractions is impossible, as noted above. As a consequence all nuclear concepts relying on a 100% separation efficiency are doomed to fail [more i30 and i42].
Inherently safe nuclear power is inherently impossible
The nuclear industry strongly suggests that nuclear power is inherently safe with inherently safe nuclear reactors. Nuclear reactors are part of an intricate system of industrial processes and activities, so even with inherently safe reactors nuclear power is not necessarily safe [more i14 and i15].
Inherently safe means that on no condition an accident or unwanted event can occur in a technical a system and would imply the availability of fail-safe materials, fail-safe design, fail-safe construction and maintenance and fail-safe human behaviour. Inherently safe nuclear reactors exist only in cyberspace, because this concept would imply the availability of 100% perfect materials and 100% perfect separation processes. Both conditions cannot be complied with, as follows from the Second Law [more i42]. Human behaviour is evidently not 100% predictable. The conclusion is that inherently safe nuclear reactors are inherently impossible, let alone the nuclear energy system as a whole.
From the Second Law follows that the mess and uselessness (entropy) of the biosphere increases by use of a mineral energy source, i.c. uranium, to such an extent that the full amount of the generated useful energy is by far insufficient to compensate for the deterioration of the biosphere caused by the energy generation [more i40 and i41].
An important difference between fossil fuels and nuclear power as regards this observation is the way the entropy generation becomes observable. A part of the entropy generation associated with the extraction of mineral energy carriers is instantly visible as disturbances of ecosystems in the mining areas, dispersal of dust, contamination of groundwater and soil by chemicals, etcetera.
The difference concerns the entropy generation associated with the conversion of the potential energy embodied in the mineral energy carriers into useful energy. When fossil fuels are burned, the combustion products and waste heat are instantly released: matter and energy are dispersed into the environment and the entropy of the biosphere rises maximally.
When uranium is fissioned the dozens of different kinds of fission products and radionuclides stay localised inside the spent fuel elements. A part of the fission entropy becomes manifest outside of the nuclear system, as waste heat, discharges of radionuclides into the environment and as radiation damage to materials and living organsms in the vicinity of the reactor.
The fission products confined in the spent fuel elements inevitably will spread into the environment when nothing is done to prevent that. Then the fission entropy becomes manifest in its full size: dispersal of tens of different kinds of radionuclides, the spread of nuclear radiation and the damage to materials and living organisms in the biosphere caused by radiation. In every respect that would mean a maximum rise of mess and uselessness.
Only by dedicated effort we can prevent the dispersal of the main part of the fission products and radioactivity generated in the nuclear reactor, by appropiate packing the radioactive wastes and by isolating it from the biosphere as best as possible [more i11]. At the moment of its generation, the main part of the fission entropy may be considered latent entropy. The longer we postpone adequate treatment of the nuclear waste, the more latent entropy will turn into actual entropy of the human environment.
The dedicated effort to prevent this disastrous scenario will require massive investments of ordered materials, useful energy and human skill: this is the energy debt [more i16].
The more specialistic the task, the higher the required quality standards of materials, design and craftsmanship for production of the material and/or object. A higher quality requires a higher investment of useful energy and human skill. This observation follows directly from the Second Law [more i40]. In nuclear technology exceedingly high quality specifications and high degrees of predictability of the behaviour of materials and equipment are required, consequently nuclear-grade constructions are extremely energy-intensive.
Advanced nuclear concepts
Advanced concepts of nuclear power generation are the uranium-plutonium breeder, the thorium-uranium breeder and partitioning & transmutation of long-lived radionuclides. Two technical achievements are a conditio sine qua non for materialization of each of these concepts:
• separation of complicated mixtures of radionuclides into pure fractions without losses,
• production of materials and machines with 100% predictable properties and behaviour.
Separation and purification processes are governed by the Second Law, which implies that both suppositions are impossible. From this observation follows that the advanced nuclear power concepts are doomed to fail in practice, as has been proved by experiences during the past 50 years, though, and consequently can exist only in cyberspace [more i30. i31, i42].
Nuclear power cannot be sustainable
Uranium is a mineral energy source recovered from the upper layers of the earth's crust, in fact within biosphere. As a consequence the entropy generation inevitably coupled to the generation of useful energy by fissioning uranium, occurs within the biosphere. Effects of increasing entropy within the biosphere always mean loss of quality of the human environment. A major part of the nuclear entropy is the generation and dispersion of radioactivity. Inevitably people are exposed to radioactivity, inflicting serious harm [more i41].
From the Second Law follows that the generated amount of useful energy from any mineral energy source is insufficient to compensate for its coupled entropy generation, even if all useful energy would applied to that purpose. As a result, by using uranium the entropy of the biosphere increases constantly, which means increasing damage and deterioration. For that reason fission power is not sustainable, nor is any other mineral energy source. Genuinely sustainable energy generation is only possible if based on solar energy [more i44].