Aug 26, 2024 · Hanford’s 100 Area is the part of the Hanford Site located along the banks of the Columbia River. It is where Hanford’s nine former plutonium production reactors are found. The nine reactors (B Reactor, C Reactor, D Reactor, DR Reactor, F Reactor, H Reactor, K East Reactor, K West Reactor, and N Reactor) were built between 1943 and 1965.