Small, annular, double-contained /sup 252/Cf fission chamber for source-driven subcriticality measurements

A small-diameter, double-contained /sup 252/Cf fission chamber design that can be inserted into a 0.95-cm (0.375-in) diameter hole or tube (such as the control rod guide tubes in pressurized water reactor (PWR) fuel elements) is described. This fission chamber can be used as a neutron driver for subcriticality measurements with irradiated PWR fuel elements. This prototype contains approximately 0.1 mu g of /sup 252/Cf, but the design has the flexibility to accommodate larger amounts of fissionable material required for PWR tests. Details of the design are presented, as well as some of the instrument's operational parameters and performance characteristics.<
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