Reactor Physicist, UKAEA, Harwell Laboratory, Didcot, Oxfordshire,
Pages: 11 Published: Jan 1989
The Harwell MTR’s DIDO and PLUTO have jointly accumulated 60 years'’ operation and much expertise has been amassed in designing irradiation rigs and loops to achieve target fuel ratings, neutron flux levels and spectra. For design purposes our modelling philosophy is based on a variety of calculational routes including Monte Carlo and collision probability methods.
The paper describes the development of the PAT (Pluto AGR Test) Loop currently being commissioned for transient testing of advanced gas-cooled reactor (AGR) fuel pins. The inreactor section of the loop, located in the D2O reflector close to the PLUTO core, includes fixed and variable density absorbers (silver and 3 He respectively) to counteract the flux tilt in the reflector and for inducing rating transients. During both steady operation and the transients the fuel pin rating distributions will be obtained from a combination of collision probability calculation flux solutions normalized to measured instantaneous flux values obtainedfrom online self-powered neutron detectors.
nuclear research and test reactors, nuclear fuel pins, neutron irradiation, radiation tests, neutron absorbers
Paper ID: STP10104S