Alco MRS-1 2116 / 2117

2116 & 2117 are located at the Nevada Test Site in the USA. They were used to support the nuclear rocket development program that ended in the early 1970s. They are still sitting there, haven't been touched since then.
(Info by R. J. Poderis)

Report, showing the units (on page 29 of the pdf-document). Below is the picture from that report.