**8. Conclusions**

The nuclear power plants survived several extreme natural events during 17,825 reactor years of operation (as per the 1st of December 2018). In spite of the Fukushima disaster that was also avoidable, the experience is demonstrating that there are sufficient knowledge and engineering means to ensure the safety of the nuclear power plants and protect the people and environment even in case of severe natural phenomena. In the chapter the conscious approach to hazard and availability of proven technical solutions against natural hazards has been demonstrated on the practical examples.

It has to be recognized, mother Gaia can cause sad surprises, outliers, black swans, and dragon kings that should not be "ab ovo" excluded from considerations. However, these are "products" of probabilistic considerations. Probabilistic considerations that are also accounting the epistemic uncertainty should be the basis of and generic approach to hazard and safety. Although the nuclear industry is widely using the argumentation with the small probabilities, the era of neglecting low probabilities is passed. It may seem to be a fatalist attitude; the new design paradigm is to provide necessary provisions and procedures for managing severe emergency situations, since a devastating natural event can never be completely ruled out.

Living in the word of risk, we should be aware what we do not know, and our lack of knowledge should be compensated consciously. Over the centuries of industrial era, risk has been always compensated by obvious benefits for the society. Obviously and with good reasons, this has changed nowadays. There are obvious and at the same time not fully understandable reasons for sensitivity and low tolerance of the society against the nuclear industry. To overcome this, the nuclear industry is making the necessary moves also with respect to the nuclear safety against natural hazards.

## **Conflict of interest**

The author declares that there are no conflicts of interest that might have any bearing on publishing of information/research reported in the submitted manuscript.

**45**

**Author details**

Tamás János Katona

University of Pécs, Pécs, Hungary

provided the original work is properly cited.

\*Address all correspondence to: bata01@t-online.hu

*Natural Hazards and Nuclear Power Plant Safety DOI: http://dx.doi.org/10.5772/intechopen.83492*

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

*Natural Hazards and Nuclear Power Plant Safety DOI: http://dx.doi.org/10.5772/intechopen.83492*

*Natural Hazards - Risk, Exposure, Response, and Resilience*

**8. Conclusions**

the practical examples.

against natural hazards.

**Conflict of interest**

manuscript.

generation is reduced, or the reactors are shutting down. The hydrometeorological extremes became more frequent and more severe due to climate changes. Assume that the return period of event with the given limiting magnitude will be 50 years as an average over the 60 years of operation instead of 100 years. In this case, the probability of economic losses will be *PE* <sup>60</sup> ≥0.7024. Over the timespan of 60 years, the worsening of hydrometeorological conditions and increase of the magnitude and frequency of extremes will affect the economy of the nuclear power production, especially those plants with freshwater cooling. Even if the values given above for the exceedance probability of magnitude of hazards for continuous operation might be not precise, the tendency is clearly showing the growing probability for

economic losses due to climate change for any thermal power plants.

The nuclear power plants survived several extreme natural events during 17,825 reactor years of operation (as per the 1st of December 2018). In spite of the Fukushima disaster that was also avoidable, the experience is demonstrating that there are sufficient knowledge and engineering means to ensure the safety of the nuclear power plants and protect the people and environment even in case of severe natural phenomena. In the chapter the conscious approach to hazard and availability of proven technical solutions against natural hazards has been demonstrated on

It has to be recognized, mother Gaia can cause sad surprises, outliers, black swans, and dragon kings that should not be "ab ovo" excluded from considerations. However, these are "products" of probabilistic considerations. Probabilistic considerations that are also accounting the epistemic uncertainty should be the basis of and generic approach to hazard and safety. Although the nuclear industry is widely using the argumentation with the small probabilities, the era of neglecting low probabilities is passed. It may seem to be a fatalist attitude; the new design paradigm is to provide necessary provisions and procedures for managing severe emergency situations, since a devastating natural event can never be completely ruled out. Living in the word of risk, we should be aware what we do not know, and our lack of knowledge should be compensated consciously. Over the centuries of industrial era, risk has been always compensated by obvious benefits for the society. Obviously and with good reasons, this has changed nowadays. There are obvious and at the same time not fully understandable reasons for sensitivity and low tolerance of the society against the nuclear industry. To overcome this, the nuclear industry is making the necessary moves also with respect to the nuclear safety

The author declares that there are no conflicts of interest that might have any bearing on publishing of information/research reported in the submitted

**44**
