The Army Package Power Reactor (APPR-1) control system was analyzed to find its response to a startup accident. The system was found to be adequate, at 0.086%/sec rod withdrawal, for operation of at least twice the rated power. (C.J.G.)

An idealized model is postulated embodying the essential features of industrial caustic-chlorine cells with horizontal flowing-mercury cathodes. This model is examined in detail, and relations expressing the local anode potential, cathode potential, and ohmic potential drop in the electrolyte in terms of local current density and other parameters are established. These relations are combined to give a system of equations relating current density at any location along the cell to applied total potential and to operating conditions in the cell upstream of the point in question. Numerical solutions of these equations for several cases of cell operating conditions are carried out on a digital computing machine. The effects of changes in operating parameters upon average current density, individual electrode potentials, and current distribution are evaluated. (auth)

A program was initiated on the spectrophotometric study of aqueous solution chemistry. The goal is operation at temperatures up to at least 330 deg C and at pressures up to 200 atm, and to near the critical point if this appears to be feasible. A spectrometer capable of operation under these extreme conditions is being designed. (W.L.H.)

To date a great deal of emphasis has been placed on flattening the side-to-side and top-to-bottom flux distribution with only minor effort to improve the front-to-rear distribution. Minor variations in the front-to-rear distribution have been achieved by horizontal control rod and Supplemental control positioning. It has-been reasonably well established that the rupture potential for one tube charge increases markedly with higher specific power and temperature; thus there is a great deal of incentive to flatten in the front-to-rear dimension. Although flattening in this dimension will caure increased neutron leakage out of the reactor, this is compensated by increased conversion efficiency resulting from a more uniform exposure distribution within the tube charge. The purpose of this document is to describe the basic analytical methods and the techniques, of flattening front-to-rear through the integrated use of enrichment and poison material in combination with natural uranium, and to point out the requirements to insure that total control criteria is satisfied in the event of a water loss with this loading. For the purpose of this survey report an old reactor, 32-piece charge length, and a symmetrical front-to-rear distribution were considered; however, the methods given can be extended quite easily to different length and …

Under the conditions of PT-IP-247-A, four columns of self-supported and four columns of rib-supported I&E 1.47% enriched fuel elements were irradiated to determine their relative performance under severe operating conditions. Four of the self-supported and two of the rib-supported control elements were received for nation. The two rib-supported control pieces, which were classified as ``near failures`` had received average exposures of 353 and 359 MWD/T at average specific power levels of 91 and 108 KW/ft before they were discharged because of other ruptured pieces in the tubes. The nominal specified canned fuel dimensions of the rib supported elements was 1.445 in. OD, .310 in bore, and 7.640 in. long. The first two self-supported elements were selected for examination on the basis of high weight losses sustained during irradiation, and the second two were selected to determine the effect of specific power levels on the AlSi bonding. The average specific power levels of the four self-supported elements varied from 79 to 110 KW/ft and the exposure varied from 845 MWD/T to 949 MWD/T. The nominal canned dimensions of the self-supported elements, which were made oversize to attain high annular coolant temperatures with respect to the interior coolant channel, were 1.460 in. …