THOROBRED is an IBM-704 code for the calculation of nuclear and economic characteristics of two-region homogeneous reactors operating on a U-Th fuel cycle in the steady state. The major input variables are reactor dimensions, power level, thorium concentration, chemical and purification systems cycle times, corrosion rates, fraction of Pa loss, and nuclear and economic data. The output includes equilibrium isotope concentrations, neutron balance, and a breakdown of fuel cost. Running times are normally less than one minute per case.

The method is based on caustic precipitation and centrifugation (which removes the Cs and small amounts of Sr, rare earths, Zr, Nb, and Ru). These are removed in the supernatant and run through a cation exchange column. This separates Zr-NB and Ru. The effluent is precipitated and the Zr-Nb is stored in an asphalt pit. The Ru then may be recovered from the precipitate. The precipitate from the original centrifugation is calcined, pressed and transported to a deep well.

Few data exist for the thermal conductivity and viscosity of gases at very high pressure. The possibility of using gases for heat transfer media at pressures up to 100 atmospheres and above raised the problem of estimating variations in the conductivity and viscosity at high pressure. Generalized plots are presented which are based on the work of Enskog, Eucken, and Hirschfelder et al. Some pertinent data from Hirschfelder et al and from Hilsenrath et al are presented.

The following temperature measurement tabulation consists of two parts. Part I lists all HRT thermocouples, their location, the junction box thru which the leads pass, and their termination, if on an instrument. Part II lists all temperature read out instruments and their location. A total of 577 thermocouples are listed in this tabulation. The roughly 77,000 ft of wire used in connecting them up cost $6,799. Temperatures are read on 24 instruments. Cost of these was approximately $15,688. Accessories such as patch panels, conduit, disconnects, etc., used in installing the thermocouples cost about $8,069. Total cost for material and instruments for temperature measure comes to approximately $30,556.

The horizontal and vertical power distribution for a 5 x 7 fuel element loading of the TSR is presented. (auth)