Failed BONUS in Puerto Rico

William Brown
November 8, 2017

Submitted as coursework for PH240, Stanford University, Fall 2017


Fig. 1: BONUS power plant in Rincon, Puerto Rico. (Source: Wikimedia Commons)

The BONUS reactor was an experimental nuclear built in Rincon, Puerto Rico, in the northwest of the island, (See Fig. 1.) It was created to test the the integral boiling super heating concept. The two main parties behind the construction of this reactor were U.S. Atomic Energy Commission and Puerto Rico Water Resources Authority.

Bonus began construction in 1960 and reached maximum usage in September of 1965. [1] The total cost to build the plant was $23,737,062. [2] The net electrical output was designed to be 16.5 MW. The plant used a conventional regenerative steam cycle that had four closed feed water heaters combined with a standard condenser cooled with sea water. [2]


Due to the need for expensive renovations and operating difficulties, all operations of the reactor ceased in June of 1968. The Puerto Rico Water Resources Commission subseqwuently deactivated the plant betwen 1969 and 1970. Cleaning of the site and insertion of shielding took place from this time through the early 2000's. The site is now considered safe for visitors and workers.

The US Department on Energy is responsible for all the radioactive materials at the site. [1] The remaining responsibilities for the site are split between the US Department of Energy and The Puerto Rico Electric Power Authority (PREPA). The future plans are to make the first floor of the power plant into a museum. It has been determined that there is no harm to human health using the first floor. [1]

© William Brown. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.


[1] " BONUS, Puerto Rico, Decommissioned Reactor Site," U.S. Department of Energy, June 2017.

[2] "Boiling Nuclear Superheater (BONUS) Power Station, Project Completion Report," U.S Atomic Energy Commission, ORO-649," June 1966.