Tank 241-A-105 is one of 149 single shell tanks constructed at Hanford to contain and store highly radioactive wastes originating from the processing of spent nuclear reactor fuel. Radiation detection and temperature monitoring devices installed beneath the tank indicate that several episodes of leakage of waste from the tank have occurred. The aim of this study was to evaluate the previous estimates and reanalyze the data to provide a more accurate estimate of leakage from the tank. The principal conclusions of this study are as follows: Earlier investigators estimated leakage prior to August 1968 at 5,000 to 15,000 gallons. Their estimate appears reasonable. Leakage while the tank was being sluiced (8/68--11/70) probably exceeded 5,000 gallons, but probably did not exceed 30,000 gallons. Insufficient data are available to be more precise. Cooling water added to the tank during the sprinkling phase (11/70 -- 12/78) was approximately 610,000 gallons. Sufficient heat was generated in the tank to evaporate most, and perhaps nearly all, of this water. Radionuclides escaping into the soil under the tank cannot be estimated directly because of many uncertainties. Based on a range of leakage from 10,000 to 45,000 gallons, assumed compositions, and decayed to 1/1/91, radioactivity under the …

This report summarizes progress on OHER human health, biological, and general life sciences research programs conducted at PNL in FY 1990. The research develops the knowledge and scientific principles necessary to identify understand, and anticipate the long-term health consequences of energy-related radiation and chemicals. Our continuing emphasis is to decrease the uncertainty of health risk estimates from existing and developing energy-related technologies through an increased of understanding of how radiation and chemicals cause biological damage. The sequence of this report of PNL research reflects the OHER programmatic structure. The first section, on human health research, concerns epidemiological and statistical studies for assessing health risks. The next section contains reports of biological research in laboratory animals and in vitro cell systems, including research with radionuclides and chemicals. The general life sciences research section reports research conducted for the OHER human genome research program.

A comprehensive literature assessment has been conducted to determine the nature and scope of technical information available to characterize the seismic performance of an underground repository and associated facilities. Significant deficiencies were identified in current practices for prediction of seismic response of underground excavations in jointed rock. Conventional analytical methods are based on a continuum representation of the host rock mass. Field observations and laboratory experiments indicate that, in jointed rock, the behavior of the joints controls the overall performance of underground excavations. Further, under repetitive seismic loading, shear displacement develops progressively at block boundaries. Field observations correlating seismicity and groundwater conditions have provided significant information on hydrological response to seismic events. However, lack of a comprehensive model of geohydrological response to seismicity has limited the transportability conclusions from field observations. Based on the literature study, matters requiring further research in relation to the Yucca Mountain repository are identified. The report focuses on understanding seismic processes in fractured tuff, and provides a basis for work on the geohydrologic response of a seismically disturbed rock mass. 220 refs., 43 figs., 11 tabs.