There is a certain amount of Electro-Magnetic Radiation that goes along with a nuclear reaction that does tend to wreak havoc on electrical systems. That is one of the reasons that military equipment costs so much. One of the easiest ways to shield against such radiation to line things with gold. But it sounds to me like Andrew has potentially suffered a melt-down. Have you ever heard of the China-Syndrome. Theoretically, the out of control reaction, basically a very slow burning nuclear bomb (Psi correct me if I am wrong) will keep burning until it burns a hole into the core of the planet. Theoretically.
Taz