On page 23 of its April 2002 issue, Physics Today reviewed the perilous state of university reactors. That article contained several oversights that may be of interest to the physics community.

First, most university reactors can be characterized as small “neutron factories” that produce neutrons for neutron scattering and activation measurements. Reactor use in those applications depends largely on faculty interest and research funding, which in some cases have been marginal. 1 Moreover, neutron scattering and activation experiments may not be closely related to the nation’s nuclear power needs.

One university reactor, however—operated by Rensselaer Polytechnic Institute in Troy, New York—is directed at reactor physics measurements and at training that is directly pertinent to the nation’s pressurized water reactors (PWRs) and boiling water reactors (BWRs). The RPI Reactor Critical Facility is alone among university reactors in that it uses fuel that is very much like commercial fuel—that is, high-density uranium oxide pellets enriched to 4.81 weight percent uranium-235 and stacked in metal cladding. The RCF measurements are similar to the “startup measurements” that every power reactor is required to make each year or two. The measurements include (1) the effects of changes in state variables such as temperature and voids on multiplication factor and (2) the effects of core structure and composition on power shape and multiplication factor.

Second, most RCF measurements are made at low power, close to 1 W. In fact, to permit access to the core for experiments, one does not want to activate the fuel by going to higher power. The annual operating energy production is usually less than .05 kWh/year, with the result that radiation doses are negligible and the facility is not appreciably activated. Another consequence is that the operating budget has been less than $40 000 per year, most of which is paid by tuition and grants. That figure is much less than the costs of $100 000 and more that may be “shouldered” by the universities.

Third, some university reactors are characterized and valued as training reactors in that they permit “real” reactor experience that contributes to learning a “safety culture.” That opinion is not universally held. Reactor simulators provide a very realistic training experience for power reactor operation. Nuclear power plants almost exclusively use simulators for training purposes, whereas they formerly used training reactors (including that at RPI) as well.

The Future of University Nuclear Engineering Programs and University Research & Training Reactors
(rep. prepared for the US Department of Energy Office of Nuclear Energy),
Washington, DC
). Final draft available online at http://www.nuclear.gov/nerac/finalblue.pdf.