The LIMB (limestone injection multi-stage burner) process offers special potential for reducing NO/sub x/ and SO/sub x/ by at least 50 percent in coal combustion. This is to be accomplished by adding limestone with fuel and/or air in a low NO/sub x/ burner. This program has been directed to defining the chemistry and kinetics necessary to optimize sulfur capture in LIMB combustion. More specifically, this program has attempted to clarify the role of calcium sulfide in LIMB chemistry. When limestone is added in a staged burner, there is a strong possibility that under certain circumstances CaS is produced in the reducing (fuel-rich) zone of the burner. Since CaS is more stable than CaSO/sub 4/, this affords the opportunity to (1) operate the burner at a higher temperature, 2200 to 2500 F, (2) pass the CaS rapidly through the high temperature zone (before dissociation), and (3) complete the combustion in a lean (air-rich) region where the sulfur is finally retained in CaSO/sub 4/. For these reasons this program has concentrated on the high temperature chemistry and kinetics of CaS. To achieve the program objective, the program was divided into three tasks. These involved (1) a study of CaS formation, (2) a …

This paper discusses calculations related to hydraulics in a loss of coolant reactor accident. Earlier calculations ignored the effect of emergency coolant injection. Present results show that if the ECS flow is considered, reactor coolant flow is maintained for much longer periods. A computer program used to carry out the calculations is included in this report. (JDH)

Progress is reported in research on the automated welding of heavy steel plate for the fabrication of pressure vessels. Information is included on: torch and shield adaptation; mechanical control of the welding process; welding parameters; joint design; filler wire optimizaton; nondestructive testing of welds; and weld repair. (LCL)

This report documents interim definitions of terms in the Seismic Safety Margins Research Program (SSMRP). Intent is to establish a common-based terminology integral to the probabilistic methods that predict more realistically the behavior of nuclear power plants during an earthquake. These definitions are a response to a request by the Nuclear Regulatory Commission Advisory Committee on Reactor Safeguards at its meeting held November 15-16, 1979.

A number of problems have conspired to prevent full operation of the PDU during the report period. After a review of the situation, it was decided to cease the day-by-day attempts to achieve PDU operation, and to review the situation and make such longer-term repairs or modifications as appeared necessary for increasing the probability of success. As a result, a list of 12 modifications was made and the modifications initiated so that PDU operation can be initiated early in the next quarter. Analysis of the data on the outgassing of zinc from the product of the miniplant was concluded, with the indication that outgassing times of the order of tens of hours would be required at 1100 C. The implications of leaving the zinc in the product, to be evolved in melting prior to ingot or sheet growth, were examined with the conclusion that at the 10-100 ppmw level of zinc in silicon, it may be difficult to detect the zinc evolution in the presence of the normal SiO evolution caused by reaction between the liquid silicon and the fused-quartz crucible.

Quasifree electrons simulate the behavior of unsolvated or dry electrons in aqueous media including the special case of biological systems. A model of direct radiosensitization was developed based on dry charge-carriers having an extended lifetime in the sheath of structured water that surrounds polar biomolecules. In this model, the pre-solvation lifetimes of dry electrons increased with an increase in the rotational times of solvent molecules. During the development of this model, an increasing number of radiosensitizers were found to be carcinogenic. Measurement of the k/sub e/'s of known carcinogens and noncarcinogens revealed that carcinogens attached quasifree electrons at diffusion-controlled rates, whereas the k/sub e/'s of noncarcinogens were significantly less. To explore the k/sub e/-carcinogenicity correlation further, a study of quasifree electron attachment to the water pools of reversed micelles was conducted. The degree of structuredness of the water pools which determines the k/sub e/ of the reversed micellar systems was also controlled. Another approach to controlling the microenvironment of quasifree electrons in biological systems was done in studies of radiation-induced damage to DNA in concentrated DNA solutions. The high concentration of DNA introduces more structure into the solutions than that occurring in typical in vitro experiments. The structural enhancement by …

We have measured transition-metal ion (Ti, V, Cr, Mn, Fe, Co, Ni, Cu) spectra and their effects on Nd fluorescence quenching in Nd-doped phosphate and silicate glasses. Our purpose was to determine the maximum allowable impurity content given particular limits on the absorption loss at 1053 nm and the Nd fluorescence quenching rate. To keep the absorption loss <0.1 m/sup -1/ the transition-metal impurity content should be kept below 0.5 ppMw. To keep the increase in the Nd fluorescence decay rate below 1%, the impurity content should be <3 ppMw. We have also found that the Nd quenching rates do not scale as predicted by the Forster-Dexter dipole-dipole energy transfer theory if we assume that the dominant variation with transition metal is the overlap integral of the Nd fluorescence spectrum and the transition-metal absorption. We suggest that phonon-assisted energy transfer to transition metals is effective in quenching Nd. We find that quenching rates increase 1.5 to 4 times as the Nd concentration increases from 0.5 to 10 x 10/sup 20/ cm/sup -3/.

The UNC Recovery Systems Company, located at Wood River Junction, Rhode Island, was involved in the recovery of enriched uranium from scrap materials generated primarily in defense program activities of the DOE and its predecessor agencies. Following shutdown of the recovery operations in August 1980, UNC was required to decontaminate facilities and the associated waste lagoon systems and to remove the resultant low-level radioactive waste out of the state of Rhode Island. In view that the waste resulted from the processing of scrap materials generated in DOE Defense Programs activities and due to the lack of adequate capacity at commercial waste disposal facilities, DOE agreed to accept the waste for burial at the Y-12 Plant. Site characterization and well monitoring results are presented of the disposal site.