Principal Engineer, Babcock & Wilcox Company, Nuclear Power Division, Lynchburg, VA
Pages: 10 Published: Jan 1989
The Babcock & Wilcox Owners Group (B&WOG) Cavity Dosimetry Benchmark experiment is the first step in the B&WOG program to develop measurement-based methodology for use in monitoring vessel fluence in the post-Reactor Vessel Surveillance Program timeframe. Ex-vessel dosimetry has been chosen as the vehicle to provide fluence measurements for use in this measurement-based methodology. (Fluence is measured indirectly by first measuring a relatable quantity and then applying the known correspondence between the measured quantity and the fluence, [e.g., Cs137 activity of a fission foil or tracks on an SSTR].) The results of the In-Out Experiment will be used in refining the analytical models and benchmarking the final methodology. The experiment will provide neutron and gamma fluence measurements, at points both inside and outside the reactor vessel, through the use of numerous fluence measuring devices. Four different categories of ex-vessel monitors have been specified, three for measuring neutron fluence and the fourth for measuring gamma fluence. The placement of the ex-vessel detectors was based on the need to obtain measurements of fluence variations in the azimuthal, radial, and axial directions. The invessel fluence will be measured using an unirradiated, standard B&W reactor vessel surveillance capsule that will be installed in a spare holder tube at the same azimuthal position as the main ex-vessel dosimetry stringer. This paper presents a detailed description of the experiment.
benchmark, cavity, dosimetry, fluence, gamma fluence, lithium fluoride (LiF), neutron fluence
Paper ID: STP10072S