Atomic Awesome

Farewell BREN, We Hardly Knew Ye

During the heyday of nuclear testing, a giant tower was built out in the Nevada desert so an unshielded reactor could be placed at the top in order to see just how much radiation made it to the ground. The BREN tower was the tallest man made structure in the US that nobody knew about, but alas, her time has passed. On May 23, the tower was demolished with explosives (yes, there is video, but honestly the tower is so tall and the cameras so far away it is a bit anti-climactic), so let’s take a look back a piece of atomic history to commemorate.

The tower was built in 1962 in the Yucca Flat testing area. Its height of 1,527 ft was designed to match the altitude Little Boy exploded over Hiroshima, and a simulated village was constructed at the base of the tower. Constructed of fifty-one 30 ft sections, the tower was higher than the Empire State Building, and designed to withstand winds exceeding 120 mph. There was an outside hoist to lift scientific equipment, and a two-person elevator inside.

During the experiments, a small unshielded reactor was set at varying heights up the tower, and the radiation levels were tested inside and around dwellings made of different materials. The name of the test, Bare Reactor Experiment, Nevada, gave the tower her name–BREN. These experiments were designed to provide a method for estimating the radiation doses received by the survivors of the atomic bombs dropped over Japan. The results of this testing was the basis of modern radiation estimates.

When the Nuclear Test Ban Treaty banned open-air nuclear testing, the tower was utilized to facilitate other tests. However, the location of the tower on Yucca Flat was considered somewhat of a hindrance to underground testing there, limiting placement and yield of the tests. It was at this point in 1966 that the BREN tower was moved to Jackass Flats. Dresser-Ideco, the same company that had build the tower, was contracted to move it.

In September of 1966 the next major experiment utilizing the tower was begun, Operation High Energy Neutron Reactions Experiment–HENRE. A small linear accelerator designed and built by Oak Ridge national laboratory was mounted to the tower and measurements taken to determine the distribution of neutrons and gamma rays produced by neutron collisions with air particles.


The last time the BREN tower was used for experiments was 1999,and it had fallen into dis-repair. Instead of spending the approximately $1 million it would have taken to restore the structure to usable condition, the decision was made to demolish the tower



Images from NNSA Nevada Site Office (first 4), highpowerrocketry blog (last image), video is from , and additional video available from CNN, but there are commercials. Via MotherBoard, information from NNSA and CNN.

  • Deartháir

    You're really kicking ass and taking names this weekend, aren't you Hyco? This is some pretty fucking awesome stuff. Now I want to sit and read about it instead of going anywhere this weekend…

  • aastrovan

    That is a good post,comprehensive,instructive and totally cool.

  • texlenin

    Well, poopie.
    I saw the tag and thought it was gonna be about the machine gun.
    Kidding! Very well-written article about something I knew nothing about.
    Learning; always learning!