In the context of this NEA project on the The Security of Energy Supply and the Contribution to Nuclear Energy, a simplified version of the S/D Index as presented in Chapter 3 was considered the most meaningful representation of the security of energy supply situation in OECD member countries in order to identify the contribution that nuclear energy can make. Energy Politics, Spring, Issue 4, pp. Amsterdam: Elsevier, pp. Plenum Press, New York, United States.