High Flux Beam Reactor Began Operation

October 1965

High Flux Beam Reactor Began Operation

Construction of the the HFBR in the mid-1960s


In 1958, a new reactor concept designed at Brookhaven was approved for construction by the Atomic Energy Commission. The High Flux Beam Reactor (HFBR), BNL's third research reactor, was built upon experience gained with the BGRR. It had become clear by 1955 that the neutron fluxes available at the Brookhaven Graphite Research Reactor were not high enough to support proposed experiments. The HFBR was designed to produce copious amounts of neutrons, which are uniquely suited for research using subatomic particles to investigate the structure of matter. The greater neutron flux cut by a third the time needed to do experiments making the reactor available to more users.

The HFBR first achieved a self-sustaining chain reaction on October 31, 1965. For more than 30 years, the HFBR was one of the premier beam reactors in the world, matched only by the Institut Laue-Langevin reactor in Grenoble, France. In the HFBR, the neutron flux reached its maximum outside the reactor core, where it was readily available for experiments, rather than inside the core, as with most reactors. Neutron beams were delivered to experimenters through beam ports that came out of the core on a tangent, rather than radiating outward as was typical in previous reactors. This improvement yielded more slow-moving neutrons, which are desirable for most research. Most research reactors built today incorporate the design innovations which first appeared in the HFBR. The reactor operated until 1996.

The research accomplishments at the HFBR included new uses of radioactive isotopes, the understanding of one-, two-, and three-dimensional magnets and superconductivity, experiments on the lifetimes and decays of many unstable, neutron-rich nuclei, and allowed researchers to study the basic nature of chemical structures.

During a routine maintenance shutdown in 1996, tritium, a radioactive form of hydrogen and a by-product of reactor operations, was found in groundwater south of the reactor. Investigations revealed that the source of the tritium was a small leak in the canal where spent reactor fuel was stored. Operations at the HFBR were suspended while the Department of Energy considered what action to take. In November 1999, the Secretary of Energy announced that the reactor would be permanently closed.

Decommissioning the HFBR

Since the HFBR was shut down many actions, including the shipment offsite of all spent fuel in 1998, were taken to prepare it for permanent decontamination and dismantling. The actions undertaken throughout the HFBR complex ensure that it remains in a safe and stable condition and prepared it for long-term surveillance and maintenance and decommissioning. (The actions taken are documented on this timeline in the year they occurred.)

A final plan for decommissioning of the reactor was completed in 2009. The plan called for phased decontamination and dismantlement with near-term removal of some highly activated components, removal of ancillary buildings and underground utilities and piping and preparation of the reactor confinement building for safe storage to be completed by 2020. The reactor vessel and remaining components will be removed and disposed of after a safe storage decay period not to exceed 65 years.

In 2009, American Recovery and Reinvestment Act (ARRA) funding allowed selected near-term actions to be accelerated from 2020 to 2011. Detailed descriptions of the actions are found in the appropriate year further down the timeline.

Documents / Links

To learn more visit the following websites:

HFBR History

HFBR Discoveries