Nuclear energy, which produces electricity domestically, can obviously reduce such dependence. The internal dimension instead is about creating the appropriate incentive mechanisms and framework to allow public and private actors to invest in adequate levels of production and transport capacity that provide continuous access to energy services at stable prices. Again, as a continuously operating baseload technology with very predictable operating costs, nuclear energy is poised to play a positive role. However, one needs to point out that the stability of operating costs is an advantage that is not always fully transmitted to consumers due to the peculiar price-setting mechanism in electricity markets. This element notwithstanding, the advantages continue to accrue of course at the societal level even if they are captured by electric utilities rather than by the retail consumer. Chapter 3 subsequently developed a specific composite indicator that enables the measurement of the level of security energy supply as well as the contribution of nuclear energy over the past 40 years, for those OECD countries for which a consistent data set was available.