nuclear-powered ship, the submarine . Later, two more prototype plant facilities, A1W and S5G, were built at this location called the Naval Reactors Facility (NRF for short). There is also an Expended Core Facility (ECF for short) also at NRF as well as administrative buildings/facilities. NRF's chemistry lab was located at the S1W prototype. By now, the prototype plants for shipboard use development have been shut down. Only the Expended Core Facility / Dry Storage Area is in use. Materials Test Reactor (MTR) When the nuclear industry was just getting started in the early 1950s, it was difficult to predict exactly how different kinds of metals and other materials would be affected by being used in a reactor for prolonged periods of time. MTR was a research reactor jointly designed by Argonne and Oak Ridge National Laboratories that operated until 1970 and provided important data, helping researchers make nuclear power reactors safer and longer lasting. BORAX experiments The Boiling Water Reactors (BORAX) experiments were five reactors built between 1953 and 1964 by Argonne National Laboratory. They proved that the boiling water concept was a feasible design for an electricity-producing nuclear reactor. The BORAX III reactor was also the first in the world to power a community (Arco, Idaho) on July 17, 1955. Other sites The Idaho Chemical Processing Plant chemically processed material from used reactor cores to recover reusable nuclear material. It is now called the . The Materials Test Area tested materials' exposure to reactor conditions. The Materials Test Area is part of the Advanced Test Reactor Complex. The Information Operations and Research Center and the Shelley-New Sweden Park and Ride lot is one of fourteen Federal properties listed for disposal by the Public Buildings Reform Board in their 2019 recommendations. Incidents and accidents 1961 fatal incident On January 3, 1961, the only fatal nuclear reactor incident in the U.S. occurred at the NRTS. An experimental reactor called SL-1 (Stationary Low-Power Plant Number 1) was destroyed when a control rod was pulled too far out of the reactor, leading to a near-instantaneous prompt-critical power excursion and steam explosion. The reactor vessel jumped up . The concussion and blast killed all three military enlisted personnel working on the reactor. Due to the extensive radioactive isotope contamination, all three were buried in lead coffins. The events are the subject of two books, one published in 2003, Idaho Falls: The untold story