Nuclear Reactors - Generalities 1. Boilers and Fuel Cycle - Systems - Main Constraints

This article, along with the next one, discusses nuclear fission reactors from the perspective of the coming century and historical timescales, measured in millennia. However, any discussion of nuclear energy must take into account other timescales:

• cosmic/geological timescales, which correspond to stellar nucleosynthesis and energy production in stars through fusion. This is also the typical time span separating us from the first fossil pile at OKLO two billion years ago. It is on this timescale that the inexhaustibility of nuclear energy is measured, thanks to the “nuclear continuum” consisting of the combination of fusion, fission, and accelerated charged particles ;

• the longevity of living species, measured in tens of millions of years;

• the period of ramp-up followed by a plateau in the production of energy sources that have accumulated over the centuries to meet humanity’s needs driven by population growth and development. This primarily refers to human and animal energy. With the dawn of the industrial era, the following emerged on a large scale: coal, oil, natural gas, hydroelectricity, and modern forms of renewable energy, including nuclear power;

• the era of the energy market – —from crisis to crisis – —which spans a decade. The energy market is the intersection of a consumer goods market and the regulation of the common good. It is buffeted by local, regional, and global political storms, making it volatile.

The challenge—scientific, industrial, and political—lies in harmonizing these time scales and implementing a continuous strategy, without disruption or failure. Such strategic management must closely integrate the fuel cycle with energy production systems: the reactors. It must ensure coherence between the short and long term, and between competitiveness in the broadest sense and sustainability. While the requirements to be met must be balanced...