When evaluating the various nuclear technology options available, it is important to keep in mind that nuclear power also has important potential in the area of non-electric applications such as desalination, hydrogen pro­duction, district heating, oil refining, tertiary oil recovery or coal gasification (see Fig. 9.11). Indeed, there is experience with nuclear power in the heat and steam market in the low-temperature range, i. e. desalination and dis­trict heating. An extension appears possible on a short term in these areas as well as for tertiary oil recovery. The petrochemical and refining industries represent another huge potential with their growing demand for hydrogen and process steam due to the increasing share of fossil fuels such as heavy oils, oil shale or tar sands entering the market. In the high-temperature heat market, nuclear is also applicable to the production processes of liquid fuels or of hydrogen by steam reforming or water splitting, compatible with the needs of the transportation sector. The feasibility of steam reforming of methane or coal gasification under nuclear conditions was already success­fully demonstrated.

There are many other industrial sectors (such as paper and pulp, food industry, automobile industry, or textile manufacturing) which have a high demand for electricity and heat/steam at various levels of temperature and pressure. In such industrial processes, the reliability and availability of the

energy supply is essential, demanding the continuous operation of their process units approaching 100%. The temperatures required cover a wide spectrum. With respect to the required capacity, 99% of the industrial users need thermal power of less than 300 MW, which accounts for about 80% of the total energy consumed. Half of the industrial users even demand thermal power in the range of less than 10 MW. Ensuring supply security by diversification of the primary energy carriers and, at the same time, limit­ing the effects of energy consumption on the environment will become more important goals in the future.

In principle, any type and size of nuclear reactor can be used as heat source for various processes and applications. No technical impediments to coupling nuclear reactors to such applications have so far been observed, although a number of safety-related studies of coupled systems may still be necessary. Different types of nuclear reactors provide a different range of coolant temperatures. The higher the temperature, the larger is the range of applications and products. Current Light Water Reactors (LWR) are characterized by maximum temperatures of less than 320°C, only allowing steam production at a lower quality. Hence, they are mainly used for elec­tricity generation with occasional steam extraction. In Fast Breeder Reactors (FBR) the coolant reaches a higher temperature of around 500°C, while High-Temperature Gas-Cooled Reactors (HTGR) are able to provide steam up to a temperature of 950°C. It is an area where nuclear energy specifically from HTGRs could play a major role in future (Fig. 9.12).

The main challenges at present are to combine nuclear power and non­electric applications into a single strategy and to establish the transition technologies from present industrial practice to emerging new resources in order to stabilize energy cost. The renewed interest in nuclear power pro­duction may lead to an increased role for nuclear energy in the area of non-electric applications, which currently are almost entirely dominated by fossil fuel energy sources. Among other advantages (including less environ­mental impact and high energy content of nuclear fuel) of the use of nuclear energy for non-electric applications is that nuclear reactors offer process heat at a wide spectrum of temperatures from some 200°C to 1000°C, which covers practically the whole range required for most non-electric applica­tions, including waste heat which can be harnessed in some very low — temperature non-electric applications such as seawater desalination.

Cogeneration may become the most suitable option for non-electric applications. In this case the steam and electricity can be produced with a single nuclear plant. The cogeneration mode has several practical advantages: an increased plant thermal efficiency, the possibility of varying the heat supply according to demand and an easier implementation, as almost all nuclear reactors for electricity production can be adapted. Thus the first nuclear non-electric applications are likely to be of the cogenera­tion type. This has been confirmed by the experience with nuclear district heating and desalination.