AN ANALOG COMPUTER MODEL OF A MULTIPLE-REGION REACTOR

A technique is presented for solving the time-spacedependent diffusion equation for a multiple-region reactor on an analog computer. The technique was applied to a reactor problem involving fuel burnup and poison buildup, while constant power was maintained by the introduction of control poison. Diffusion across boundaries is computed by putting the interregion neutron diffusion into the form of a surface integral. This method allows a good flux plot to be made by means of only six spatial points. A sample problem was worked by this technique and compared to a digital solution. All computations, circuits, and operating information necessary to duplicate the experiment are given. Also, results are included and compared with a digital computation. (auth)