A nuclear plant fails near Middletown, PA almost completely melting! Researchers say that either a mechanical or electrical failure prevented the main feed water pumps from sending water to the steam generators that remove heat from the reactor core. This caused the plant's turbine-generator and the reactor itself to automatically shut down. Due to this, the pressure increased, in an attempt to control it the pilot- operator relief valve opened, however it should have shut when the pressures returned to normal but it never did. Because the plant never notified the workers the valve never shut, cooling water was pouring out reducing the pressure so much that the reactor coolant pumps had to be turned off to prevent dangerous vibrations. To prevent the pressurizer from filling up completely, the staff reduced how much emergency cooling water was being pumped in to the primary system. These actions starved the reactor core of coolant, causing it to overheat. Without the proper water flow, the nuclear fuel overheated to the point at which the zirconium cladding ruptured and the fuel pellets began to melt. Within a short time, chemical reactions in the melting fuel created a large hydrogen bubble in the dome of the pressure vessel, the container that holds the reactor core. NRC officials worried the hydrogen bubble might burn or even explode and rupture the pressure vessel. In that event, the core would fall into the containment building and perhaps cause a breach of containment. Some health effects are to be: metallic taste, erythema, nausea, vomiting, diarrhea, hair loss, deaths of pets and farm and wild animals, and damage to plants.