During design reviews of the Recycle Colection Tank (RCT) at the Savannah River Site it was determined that in all cases the RCT scrub solution could not be routed to the RCT. During transfers to the tank farm (estimated ten hour cycle), the ammonia evolved from the RCT is scrubbed by the RCT scrubber and the ammonia scrub water must be returned to the SMECT. The result of this is an increased steady state concentration of ammonium in the SMECT water used for the ammonia scrubbers. The maximum ammonium concentration is necessary for the sizing of the ammonia scrubbers for the Sludge Receipt and Adjustment Tank (SRAT),Slurry Mix Evaporator (SME), and RCT.

Three experiments were conducted within a semiarid shrubland to test the role of nitrogen availability as a control mechanism in secondary succession. Secondary succession patterns were documented for seven years and effects of increased and decreased N availability levels, fumigation, and competition by early-seral species were tested. Differential responses by seral species were determined and related to successional patterns. Nitrogen availability was found to be a primary mechanism controlling the rate of succession. Relative growth rate was an important factor determining which species initially dominated and N availability became the primary control factor by the third year. As N availability increased, the rate of succession decreased. Conversely, as N availability was decreased, the rate of succession increased. The abundance of annuals was increased and abundance of perennials decreased by increased N availability. Tissue N concentration was related to lifeform and seral position, and these relationships were important in the transition from early- to mid-seral stages. Decomposer subsystem dynamics were correlated with seral community dynamics. The effect of fumigation was minimized by initially planting with late-seral species. A conceptual model of secondary succession is presented based on N availability, relative growth rate, lifeform, and decomposition dynamics.

An in-tank ion exchange column, described here, has been constructed to operate in the waste tanks at the Savannah River Technology Center (SRTC). The purpose of the column is to remove dissolved mercury from laboratory wastes and capture them on Duolite{trademark} GT-73 resin. This paper summarizes the results of operation of such a column on two batches of waste in one high activity tank and on one batch of waste in a low activity tank for the purpose of removing mercury from the liquid wastes. Sufficient mercury decontamination was demonstrated with the in-tank resin removal system, after twenty four hours of operation in each tank, to render the waste nonhazardous and enable shipment to the F-Area evaporator.

During design reviews of the Recycle Colection Tank (RCT) at the Savannah River Site it was determined that in all cases the RCT scrub solution could not be routed to the RCT. During transfers to the tank farm (estimated ten hour cycle), the ammonia evolved from the RCT is scrubbed by the RCT scrubber and the ammonia scrub water must be returned to the SMECT. The result of this is an increased steady state concentration of ammonium in the SMECT water used for the ammonia scrubbers. The maximum ammonium concentration is necessary for the sizing of the ammonia scrubbers for the Sludge Receipt and Adjustment Tank (SRAT),Slurry Mix Evaporator (SME), and RCT.

This study sought to determine and understand the major processes governing the abundance, distribution, composition and eventual fate of zooplankton on the southeastern shelf of the US in relation to water circulation. Over much of the shelf circulation is dominated by the Gulf Stream and/or atmospheric forcing. Most of our studies concentrated on processes on the middle and outer shelf. On the latter, pronounced biological production occurs year-round at frequent intervals and is due to Gulf Stream eddies which move by at an average frequency of one every week. These eddies are rich in nutrients which, when upwelled into the euphoric zone, lead to pronounced primary production which then triggers zooplankton production.

While other programs check for bad passwords after the fact, it in important to have good passwords at all times, not just after the latest Crack run. To this end we have modified Larry Wall's Perl password program and added, among other features, the ability to check a sorted list of all the bad passwords'' that Crack will generate, given all the dictionaries that we could get our hands on (107 MB of unique words, so far). The combination of improvements has turned publicly available code into a powerful tool that can aid sites in the maintenance of local security.

This study sought to determine and understand the major processes governing the abundance, distribution, composition and eventual fate of zooplankton on the southeastern shelf of the US in relation to water circulation. Over much of the shelf circulation is dominated by the Gulf Stream and/or atmospheric forcing. Most of our studies concentrated on processes on the middle and outer shelf. On the latter, pronounced biological production occurs year-round at frequent intervals and is due to Gulf Stream eddies which move by at an average frequency of one every week. These eddies are rich in nutrients which, when upwelled into the euphoric zone, lead to pronounced primary production which then triggers zooplankton production.

An in-tank ion exchange column, described here, has been constructed to operate in the waste tanks at the Savannah River Technology Center (SRTC). The purpose of the column is to remove dissolved mercury from laboratory wastes and capture them on Duolite[trademark] GT-73 resin. This paper summarizes the results of operation of such a column on two batches of waste in one high activity tank and on one batch of waste in a low activity tank for the purpose of removing mercury from the liquid wastes. Sufficient mercury decontamination was demonstrated with the in-tank resin removal system, after twenty four hours of operation in each tank, to render the waste nonhazardous and enable shipment to the F-Area evaporator.

While other programs check for bad passwords after the fact, it in important to have good passwords at all times, not just after the latest Crack run. To this end we have modified Larry Wall`s Perl password program and added, among other features, the ability to check a sorted list of all the ``bad passwords`` that Crack will generate, given all the dictionaries that we could get our hands on (107 MB of unique words, so far). The combination of improvements has turned publicly available code into a powerful tool that can aid sites in the maintenance of local security.

Three experiments were conducted within a semiarid shrubland to test the role of nitrogen availability as a control mechanism in secondary succession. Secondary succession patterns were documented for seven years and effects of increased and decreased N availability levels, fumigation, and competition by early-seral species were tested. Differential responses by seral species were determined and related to successional patterns. Nitrogen availability was found to be a primary mechanism controlling the rate of succession. Relative growth rate was an important factor determining which species initially dominated and N availability became the primary control factor by the third year. As N availability increased, the rate of succession decreased. Conversely, as N availability was decreased, the rate of succession increased. The abundance of annuals was increased and abundance of perennials decreased by increased N availability. Tissue N concentration was related to lifeform and seral position, and these relationships were important in the transition from early- to mid-seral stages. Decomposer subsystem dynamics were correlated with seral community dynamics. The effect of fumigation was minimized by initially planting with late-seral species. A conceptual model of secondary succession is presented based on N availability, relative growth rate, lifeform, and decomposition dynamics.