Before an Emergency - Nuclear Power Plant

Diablo Canyon Power Plant, which is owned by Pacific Gas and Electric Company (PG&E), has been generating nuclear power since 1985.  The plant currently provides electricity to more than 1.6 million homes through two 1,100 megawatt reactors. The plant is located in Avila Beach and surrounded by approximately 12,000 acres that are managed by PG&E.  

Diablo Canyon Power Plant website

The Pressurized Water Nuclear Reactor

In a pressurized water nuclear reactor, there are three separate and enclosed water loops. Within the first loop, water, under pressure to prevent boiling, flows through the reactor fuel core and is heated by nuclear fission. The heated water passes through the stream generator where it transfers its heat to the water in the second loop and is then pumped back into the reactor to be reheated. The water in the second loop boils into steam and rushes with great force into the turbine where it strikes blades causing an attached shaft to spin. The other end of the shaft spins inside a generator, producing electricity. Within the third loop, cooling water, drawn from an outside source, condenses the steam after its energy is spent. The cooling water is returned to its source while the reconverted water is pumped back to the stream generator.

The above is an illustration of the power transfer in a pressurized water reactor such as Diablo Canyon Power Plant.  Graphic courtesy of the Nuclear Regulatory Commission.

NPP Administrative Plan