Pressures are mounting for a regime to verify the dismantlement of US and Russian warheads, as well as a system of international control over the weapons` fissile materials to assure irreversibility. There are at least four motivating factors for these measures: (1) as the United States and Russia lower their numbers of nuclear weapons, each side seeks assurance that the warheads are actually being dismantled; (2) by accounting for the fissile materials and placing them under effective controls, the potential for smuggling and theft is reduced; (3) a fissile materials cutoff is being discussed at the Conference on Disarmament in Geneva; verification of a US-Russian cutoff, as well as substantial reductions in fissile materials stockpiles, are seen as integral to the cutoff; (4) calls for total nuclear disarmament have greatly increased; dismantlement verification and international control of fissile materials are widely viewed as requisite steps toward this goal. There are many questions to be answered before the United States can agree to a warhead verification regime and international control over excess fissile materials, let alone total nuclear disarmament. Two of the most important are: What are the prospects for effective verification? and How much fissile material can be declared as …

Researchers from Brookhaven National Laboratory (BNL) tested perfluorocarbon (PFT) gas tracers on a subsurface barrier with known flaws at the Waldo test facility [operated by Science and Engineering Associates, Inc (SEA)]. The tests involved the use of five unique PFT tracers with a different tracer injected along the interior of each wall of the barrier. A fifth tracer was injected exterior to the barrier to examine the validity of diffusion controlled transport of the PFTs. The PFTs were injected for three days at a nominal flow rate of 15 cm{sup 3}/min and a concentrations in the range of a few hundred ppm. Approximately 65 liters of air laced with tracer was injected for each tracer. The tracers were able to accurately detect the presence of the engineered flaws. Two flaws were detected on the north and east walls and lane flaw was detected on the south and west walls. In addition, one non-engineered flaw at the seam between the north and east walls was also detected. The use of multiple tracers provided independent confirmation of the flaws and permitted a distinction between tracers arriving at a monitoring port after being released from a nearby flaw and non-engineered flaws. The PFTs …

Significant effort is being devoted to the development of noninvasive imaging systems that allow in vivo assessment of biological and biomolecular interactions in mice and other small animals. Although single-photon emission tomography (SPECT) and positron emission tomography (PET) are well-matched to the study of physiological function in small animals, the spatial resolutions of 1-2 mm currently achievable with these techniques limits the types of research possible. For this reason, we are developing a small animal radionuclide imaging system using grazing incidence optics to focus the low-energy gamma-rays emitted by {sup 125}I, {sup 95m}Tc, {sup 96}Tc, and {sup 99m}Tc. We compare this approach to the more traditional use of absorptive collimation.

Two small quantity transuranic (TRU) waste generator sites have gained considerable experience in navigating through a changing regulatory landscape in their efforts to remove the TRU waste from their sites and proceed with site remediation. The Battelle Columbus Laboratories Decommissioning Project (BCLDP) has the objectives of decontaminating nuclear research buildings and associated grounds and remediating to a level of residual contamination allowing future use without radiological restrictions. As directed by Congress, BCLDP must complete decontamination and decommissioning activities by the end of Fiscal Year (FY) 2006. This schedule requires the containerization of all TRU waste in 2002. BCLDP will generate a total of approximately 27 cubic meters (m3) of remote-handled (RH) TRU waste. Similarly, the Energy Technology Engineering Center (ETEC) is scheduled to close in 2006 pursuant to an agreement between the U.S. Department of Energy (DOE) and Boeing Canoga Park, the management and operating contractor for ETEC. ETEC had 11.0 m3 of RH-TRU and contact-handled (CH) TRU waste in storage, with the requirement to remove this waste in 2002 in order to meet their site closure schedule. The individual milestones for BCLDP and ETEC necessitated the establishment of site-specific programs to direct packaging and characterization of RH-TRU waste before …