The startup and operation of the Torrey Pines FLIP Mark III TRIGA

On June 8, 1971, The Torrey Pines TRIGA Mark III reactor went critical on a core loading of FLIP (Fuel Lifetime Improvement Program) fuel. This new TRIGA fuel, which was developed by Gulf Energy and Environmental Systems, contains 70% enriched uranium and erbium as a burnable poison alloyed with 91 wt-% zirconium. The reactor achieved criticality with 53 FLIP fuel elements and was then loaded to a total of 67 fuel elements after calibrating the control rods. A number of tests were performed on the core. Although there were a few problems related to the startup, once the reactor was on the line the FLIP core performed very much like the old 20%-enriched core