M.W. Cappiello

The Los Alamos National Laboratory is developing the Transient Reactor Analysis Code (TRAC) to provide advanced best-estimate simulations of real and postulated transients in pressurized light-water reactors and for many related thermal-hydraulic facilities. The TRAC-PF1/MOD1 program is the latest released version. The code features a one- and/or three-dimensional, two-fluid treatment for the thermal hydraulics, together with other necessary modeling capabilities to describe a reactor system. This report complements the TRAC-PF1/MOD1 code manual and provides much more detailed descriptions of the various correlations and models utilized by the code. These correlations and models in general provide the necessary closure relations required by the field equations and also provide additional models necessary for the transient simulations. The report is primarily an audit, or a detailed description, of the correlations and models as represented in the code. The report also provides the basis for each through references to original literature and/or a description of the development process; lists the assumptions made in the implementation, including the definitions of required parameters not normally calculated by the code; and describes other details of the implementation. A partial assessment has been provided of some of the more important, less well-founded correlations and models to indicate themore » inherent accuracy, although it is believed that a true measure of overall code accuracy must include assessment of the code against integral experiment data because of synergistic effects.« less

Tritium is a radioactive isotope of hydrogen used in all United States nuclear weapons. Because the half-life of tritium is short, 12.3 years. it must be periodically replaced. To provide a new source, the United States Department of Energy is sponsoring conceptual design and engineering development and demonstration activities for a plant that will use a high-power proton linear accelerator to produce tritium. This paper presents an overview of activities planned or underway to support that work.

A conceptual target and blanket design for an accelerator transmutation of waste system capable of transmuting the high-level waste stream from 2.5 light water reactors is described. Typically, four such targetblanket designs would be served by a single linear accelerator. The target consists of rows of solid tungsten rod bundles, cooled by heavy water and surrounded by a lead annulus. The annular blanket, which surrounds the target, consists of a set of actinide-oxide-slurrybearing tubes, each 3 m long, surrounded by heavy water moderator. Heat is removed from the slurry tubes by passing the slurry through an external heat exchanger. Long-lived fission products are burned in regions that are separate from the actinides. Using the Monte Carlo codes LAHET and MCNP, a conceptual design for a beam current of 62.5 mA/target of 1.6-GeV protons has been developed. Preliminary engineering analyses on key system components have been performed. A preliminary layout of the concept and the associated primary-heat transport subsystems was developed, demonstrating a multiple-containment-boundary design philosophy.