Fast reactor analytical shielding progress report for July and August 1973. 189a No. 10318, activity No. HN 04 01 01 1

Analytical shielding work performed for the fast reactor program during the months of July and August included calculations for both the FFTF and the Demo plant, computer code development, analyses of TSF experiments, and a cross- section sensitivity study of a TSF experiment. Most of the FFTF studies were aimed at determining the effect of various design changes on the dose rates at the maintenance deck during reactor operation, in particular, the effects of penetrations through the radial cavity shield and the effect of a new design for the head temperature control system shield. Gamma-ray dose rates due to the activated sodium coolant were also calculated for two locations in the system: around one of the branch-arm piping shields and near the entrances of the 28-in. and 16-in. coolant lines into the IHX cell. The main Demo plant study was for the lower axial shield region; another study has been initiated to calculate the Demo stored-fuel power and the ex-vessel detector response. The code development consisted in setting forth a set of specifications for the fourth version of the discrete ordinates code DOT. The TSF experiments that were analyzed were an experiment in which secondary gammaray production in iron-polyethylene configurations was investigated and another in which the transmission of the Westinghouse spectrum modifier and 5-in. radial blanket was measured. The sensitivtty study was performed to demonstrate that estimates of the accuracy of calculations for the FFTF and Demo plant can be deduced from a sensitivity study of an experimental configuration that only roughly mocks up the real system. (auth)