After over half a century of operations, the oldest research reactor in the USA has been licensed to operate for a further 20 years.
The Penn State Breazeale Reactor (PSBR) first received an operating licence from the US Atomic Energy Commission (AEC) in 1955 and went critical on 15 August that year. Its licence number - R-2 - belies that it was in fact the first research reactor to be licensed by the forerunner of the Nuclear Regulatory Commission (NRC). Licence R-1 was reserved by AEC and granted retrospectively to a reactor at the North Carolina State College which had started up in September 1953 but had already ceased operating by before PSBR went critical. The Carolina reactor never restarted; the R-2 licence for PSBR has never lapsed.