Experimental Boiling Water Reactor 1. The extremely stable Experimental Boiling Water Reactor (EBWR) in 1956. It proved that a direct cycle boiling water reactor system could operate, even at power levels five times its rated heat output, without serious radioactive contamination of the steam turbine. EBWR, operated with a largely plutonium core, provided valuable information on plutonium recycle operation of water reactors -- it generated plutonium-based electricity for Argonne's physical plant in 1966. When closed down the following year, EBWR had established a reputation as the forerunner of many commercial nuclear energy plants. One of those is the Commonwealth Edison facility at Dresden, Ill., which in 1960, became the first privately operated nuclear energy plant.