17-1 Introduction

This chapter considers the external impact of crashing aircraft, sabotage and the effect of explosive pressure wave. The external impact is considered with reference to engineering defence measures: aircraft impact, otherwise, can be prevented, with variable degrees of effectiveness, by provisions such as by modifying flight corridors or by protecting the nuclear power plant with special forces, etc.

17-2 Aircraft crash impact

The first type of strong external impact due to human activities considered for nuclear plants was that of a crashing aircraft. This kind of load started to be included among the usual design conditions, together with the pressure wave, in the 1960s and 1970s in Germany as a result of several accidents primarily involving the Lockheed F-104 Starfighter. However, for conservatism, the reference aircraft chosen was the McDonnell-Douglas F-4 Phantom. The same approach was then followed by other countries, such as Belgium, Switzerland and Italy.

Subsequently, it became clear that, in some countries, nuclear plants should also be protected against external acts of sabotage, involving aircraft, but also against launched explosive charges. It was then discovered that the protection against aircraft impact of the type described above, also gave protection against many plausible similar events, at least from the structural point of view.