Performance assessments are required for low-level radioactive waste disposal facilities to demonstrate compliance with the performance objectives, consider human exposures from water, air, and inadvertent intruder pathways. Among these, the groundwater pathway analysis usually involves complex numerical simulations with results which are often difficult to verify and interpret. This paper presents a technique to identify and simplify the essential parts of the groundwater analysis. The transport process of radionuclides including infiltration of precipitation, leachate generation, and advection and dispersion in the groundwater is divided into several steps. For each step, a simple analytical model is constructed and refined to capture the dominant phenomena represented in the complex analysis included in a site-specific performance assessment. This step-wise approach provides a means for gaining insights into the transport process and obtaining reasonable estimates of relevant quantities for facility design and site evaluation.

The design, installation and performance data of a 20 W pulsed laser system for the 3 meter Shane telescope at the Lick Observatory is presented.

Radioactive material packages containing fiberboard insulation have been subjected to Hypothetical Accident Condition (HAC) thermal tests for many years. Historically, the packages` thermal performance has always been difficult to grasp. A package designer needs to understand the effects of temperature and pyrolysis on the rate of heat transfer and performance. This paper describes in detail the one-dimensional HAC thermal tests performed on fiberboard to understand the effects of pyrolysis, its char and its gas products. The tests were conducted by the Packaging and Transportation Group at the Savannah River Site (SRS). Test fixtures were assembled at SRS and thermal testing conducted in the Radiant Heat Facility at the Sandia National Laboratories. Descriptions of the test fixtures are provided, as well as the time dependent temperature profiles. In addition, lessons learned are discussed.