BORAX-V Nuclear Superheat Operating Experience

BORAX-V was the fifth in a series of boiling-water reactors operated by Argonne National Laboratory at the National Reactor Testing Station in Idaho. It was the first integral boiling-water nuclear superheating reactor to be operated in the United States. Super-heated steam was produced, in different experiments, in both the central and peripheral regions of the core. The nominal design maximum power of 20 MW(th) and 850°F exit steam temperature were both exceeded. Operational procedures and results of experiments are discussed. Areas of particular interest and investigation include the following: comparison of a centrally versus a peripherally located superheater core; superheater startup and shutdown cooling problems; superheater flooding reactivity worth and inadvertent flooding hazard; control of power split between the boiler and superheater zones of the reactor core; superheater fuel-cladding-material integrity; plant radioactivity levels; results of operation with defective fuel in both the boiler and superheater areas of the core; in-core instrumentation and data collection; transfer-function and physics experiments; and the water-chemistry program.