Soviet advisors reportedly told Cuban officials they could not guarantee that valves installed in the first reactor's emergency cooling system would function under certain conditions. In tropical areas, such machinery must be stored in climate controlled facilities to avoid serious corrosion and other damage which can cause a breach in the structural integrity of nuclear reactors. Such corrosion has already taken place. In a number of cases, equipment designed for one specific function has been used for other purposes when the appropriate components were unavailable. This sort of jury- rigging increases the chances of systemic failures.
Construction supporting primary reactor components contains numerous structural defects .
The first reactor's dome would not be able to contain overpressures associated with meltdown conditions. In addition, the reactor containment structure contains defective welds in its seals. Cuba's human and technological infrastructure is vastly inferior to that of the former Soviet Union. And as the Chernobyl accident demonstrated at incalculable cost, even the old Soviet infrastructure proved inadequate safely to design, construct and operate nuclear plants. The Cuban government has, therefore, been anxious to allay concerns about its irretrievably flawed nuclear reactor program.