Historical perspective of a nuclear power plant at risk in a war zone

The past seven decades the design and structural material of nuclear installations has improved and their safety precludes the possibility of severe accidents in GEN-III and III⁺ nuclear power plants (NPP). Zaporizhzhya GEN-III⁺-NPP (Ukraine), is used as subject of discussion. This NPP suffered a military attack this 2022. We discuss the possibility of a severe nuclear accident and the release of radioactive material, as a consequence of an adverse structural damage. Clearly, damage to a GEN-II, -III⁺ reactor dome by military ordnance can only be estimated from data gained during past nuclear accidents in a war zone, or in the neighborhood of military targets. We report historical experiences of reactors in a war zone or under direct military attack. Based on the available data we will discuss possible scenarios applicable to a nuclear installation in Ukraine. The concrete containment of buildings protecting the nuclear vessel and its LEU-fuel loaded core, are not designed to withstand military attacks. We will discuss possible consequences of a severe structural damage due to weaponry. Estimations will be made considering the VVER-1000 Zaporizhzhya ZNPP, class GEN-III+ built near the city of Enerhodar, Ukraine. This reactor has a 2m-plus-steel-reinforced containment. It is also discussed that spent-fuel temporal reservoirs in war zones, are higher-risk structures with higher likelihood of severe radioactive material release than NPP reactors.