Incoming links: Cold War
sgp.fas.org/othergov/doe/pu50yc.html mentions:That site also contains a good summary of the closed shutdown reactors in each site. These are publicly disclosed e.g. at: www.hanford.gov/page.cfm/ProjectsFacilities
The United States Government has used 14 plutonium production reactors at the Hanford and Savannah River sites to produce plutonium for the U.S. nuclear weapons stockpile and DOE research and development programs. From 1944 to 1994, these reactors produced 103.4 metric tons of plutonium; 67.4 MT at Hanford, and 36.1 at Savannah River.
www.youtube.com/watch?v=qwKhz7BPBLY mentions that before they stopped production at the end of the Cold War, Hanford site produced 2/3 of the total American stockpile, and Savannah River site produced 1/3.
www.reuters.com/article/world/americas-nuclear-headache-old-plutonium-with-nowhere-to-go-idUSKBN1HR1JT/ claims that as of 2018 Savannah River site stored the majority of the stockpile.
TODO is there any information available on active breeder reactors? Hanford apparently shutdown.
The B Reactor of the facility produced the plutonium used for Trinity and Fat Man, and then for many more thousand bombs during the Cold War. More precisely, this was done at
Located in Washington, in a dry place the middle of the mountainous areas of the Western United States, where basically no one lives. The Columbia river is however nearby, that river is quite large, and provided the water needed by their activities, notably for cooling the nuclear reactors. It is worth it having look on Google Maps to get a feel for the region.
Unlike many other such laboratories, this one did not become a United States Department of Energy national laboratories. It was likely just too polluted.
Bibliography:
Aerial image of the Hanford site in 1960
. Source. 