Brookhaven Medical Research Reactor Began Operation

March 1959

Brookhaven Medical Research Reactor Began Operation

Brookhaven Medical Research Reactor


The Brookhaven Medical Research Reactor (BMRR) was built to meet scientists need for neutrons for medical research applications and therapy. It was the first reactor in the nation to be constructed specifically for medical research and reached criticality on March 15, 1959. It operated until December 2000.

The BMRR was a 5-megawatt (thermal) reactor 1,000 times smaller than the typical power reactor. It was similar in size to about 30 other research reactors that could be found around the U.S. during the years it operated.

One of the reactor's four faces was equipped to irradiate large objects, while the holes that penetrated another face permitted irradiation of samples, activation analysis, and production of short-lived radioisotopes. Streams of neutrons traveled to treatment rooms from the two remaining ports for carefully controlled animal and clinical studies. One of the treatments pioneered at this reactor was boron neutron capture therapy, or BNCT. This treatment was developed for possible use against glioblastoma multiforme, a deadly form of brain cancer. While this research has not been conducted at BNL since the 1990s, studies using BNCT as a possible treatment of cancer are ongoing at other institutions around the world.

Decommissioning the BMRR

The last of the nuclear fuel at BNL was shipped off of the Laboratory site on January 28, 2003. Forty-one fuel elements from the BMRR were transported by truck to the Department of Energy's Savannah River Site in South Carolina. Maintenance requirements for the BMRR were downgraded and the facility was prepared for long-term surveillance and maintenance. The BMRR is currently waiting to be decommissioned.

Documents / Links

Learn more about the BMRR