Reactor operating conditions are formally established to conserve pile life. A major part of the 2000 Research and Development effort is oriented to develop fundamental information required to properly establish these limiting operating conditions. This report reviews the current condition of reactor components believed important to continued productive life of the reactors and discusses the current status of technologies important in estimating the future productive life of the reactor complex. These evaluations are conducted continuously and this report is one of a series of status reports.

A study was conducted on the safety aspects of foreseeable accident types in connection with the Nuclear Merchant Ship Reactor program. Four accidents have been selected for analysis by analog simulation techniques: continuous rod withdrawal, startup, loss of coolant flow, and cold-water insertion. The simulation of the reactor only was required for these situations because the effects of the accidents would be completed in less than one primary- coolant loop time. The external control system was ignored, and only the effects of the negative reactivity cocfficients were considered in the natural shutdown of the plant. Three phases of operation were considered in these analyses: operation with no safety system, high-flux scram, and period scram. The programs involved the variations of the scram parameters and the reactor temperature coefficients over the range of possible values for this reactor power plant. Results indicate that the inherent stabliity of the reactor system is sufficient to attenuate the power excursions resulting from the first three accidents. In the coldwater accident, if the difference in loop temperatures is on the order of 300 deg F, scram is necessary to limit the power excursion. (auth)

This report is the second amendment to the Preliminary Hazards Summary Report for the Dresden Nuclear Power Station (GEAP-1044) submitted to the United States Atomic Energy Commission on September 3, 1957.