In coolant system such as NPR's, the coolant activity level increase with each succeeding pass through the reactor flux until a saturation limit is reached. Therefore, the activity level of the NPR coolant system will be much higher than that of the old reactor once-through systems. This report is the determination of the specific activities (disintegrations/cc{center dot}sec) of the various coolant impurities which determine the total activity of the coolant system. 10 refs., 13 figs., 2 tabs.

K area emergency water backup studies have been hampered by poor data on flow through the reactor under various emergency conditions. Various tests have been run where emergency conditions have been simulated and flow measurements attempted. In all previous tests, the accuracy of the flow measurements have been questionable. Flow from the high-pressure crosstie can be measured by an orifice in the crosstie, but there has not been any method of measuring the service water contribution to total reactor flow under simulated emergency conditions. One method of measuring the total reactor flow regardless of its source is to determine the relationship between total flow through the reactor and the bottom of riser pressure. After this relationship has been determined for the flow range of interest, then flow to the reactor can be determined by reading bottom of riser pressure (BORP) and converting that to flow. The objective of this production test was to obtain the relationship between BORP and total reactor flow in the range of 10,000 gpm to 25,000 gpm. An additional objective of this test was to check the accuracy of the No. 2 pump discharge venturi.

A nonnuclear explosion involving an evaporator occurred in a shielded cell in the Radiochemical Processing Pilot Plant at Oak Ridge National Laboratory on Nov. 20, 1959. Plutonium was released from the processing cell, probably as an aerosol of fine particles of plutonium oxide. It is probable that this evaporator system had accumulated -1100 g of nitric acid-insoluble plutonium in the steam stripper packing; the explosion released an estimated 150 g inside Cell 6, with about 135 g in the evaporator subcell, and about 15 g in the larger main cell. No radioactive material was released from the ventilation stacks; no contamination of grounds and facilities occurred outside of a relatively small area of OaK Ridge National Laboratory immediately adjacent to the explosion. No one was injured by the explosion, and no one received more than 2% of a lifetime body burden of plutonium or an overexposure to sources of ionizing radiation either at the time of the incident or daring subsequent cleanup operations. The explosion is considerdd to be the result of rapid reaction of nitrated organic compounds formed by the inadvertent nitration of about 14 liters of a proprietary decontaminating reagent. In cleanup the contamination was bonded to the …

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Earlier this year we briefly discussed the potential hazard of incurring an inadvertent uranium fuel element fire during discharge. This letter will provide data which will be of assistance to you in assessing the potential hazard, and in establishing charge-discharge procedures to minimize the probability of an irradiated fuel element lodged in the discharge area reaching aluminum jacket melting temperature without detection.