Biological Reference Points for Fisheries Management Under Environmental Changes

biological reference points (BRPs) for fisheries management under environmental changes, supported by Fisheries Agency of Japan. The objectives of this workshop are to review various BRPs for fish stocks including tuna and other fish species and to discuss the appropriate BRPs for temperate tunas considering the characteristics of biology and fishery for these species, environmental and ecosystem, and socio-economic effects. The key points of twelve presentations are provided below plus a short summary of the discussion are as follows. Participants were not necessarily representing the positions of their affiliated organizations. Japanese coastal fisheries have long history and some of them have never experienced the stock level of Bmsy. Bloss, which is the historically smallest biomass with enough RPS, is easier to be understood by fishermen, because fishermen know well from their experience that the stock biomass had fluctuated. Considering on the hardness to estimate MSY, for the stocks in North Pacific Ocean which had experienced various fishing intensity and had fluctuation of biomass, Bloss would have similar performance with Bmsy. Bmsy and Fmsy are not used for the management of TAC stocks in Japanese coastal fisheries, because the density dependence in S-R relation is not clear and there is uncertaint

Current status of the GLASS code

This paper summarizes the current status of the Generalized Lattice Analysis SubSystem (GLASS) computer code and its supporting cross section libraries. GLASS was developed at the Savannah River Site (SRS) in the early 1970's. The GLASS code has been instrumental in supporting safe Heavy Water Reactor (HWR) operations and predicting material production at SRS for more than 20 years. The Department of Energy Office of New Production Reactors (ONPR) program has chosen to use the GLASS code for the design of the HWR option of the New Production Reactor (NPR). A substantial body of validation calculations have been performed and additional validation calculations will be performed to qualify the new GLASS multigroup cross section libraries derived from the ENDF/B-5 and 6 nuclear data files. Several improvements to the code are in progress. Many other improvements are planned to bring GLASS up to modern physics and compute technology

Groundwater clean-up: The Savannah River Site experience

Protection of the Earth's valuable resources is of great concern to the public in relation to safety and health. One of the resources receiving extensive attention is groundwater. Past waste disposal practices have impacted groundwater quality in many locations throughout the nation. In response, the Federal Government has passed legislation to protect and restore the environment. In many cases, application of this legislation has lead to strict clean-up standards. Savannah River Site (SRS) experiences suggest that meeting clean-up standards is a challenge in light of technical realities. The purpose of this paper is to describe the corrective action program that is addressing a plume of volatile organics beneath the A/M Area of the SRS. The history and status of the program, costs, measures of performance, lessons learned, and challenges faced are presented

Project management controls

Project management controls are utilized to enhance the probability that a project will be successful. The control system used by a project manager can take many forms and can be applied at different times to varying degrees on a given project depending upon its complexity. The Consolidated Incineration Facility (CIF) is one project of many at the Savannah River Site (SRS). The United States Department of Energy Order 4700.1 is a project management system that is applied on a site-wide basis, thus including the CIF. The control system required by this order is proceduralized to ensure that it is applied in a consistent manner and will produce reliable results. These results provide the project manager with a correlation of both costs and schedule within the defined scope to adequately asses the status of the project. This is an iterative process and can be simply stated: plan, actual, variance, corrective action, prediction, and revision. This paper presents the basis for the project management controls applied at the Savannah River Site

Concepts for detritiation of waste liquids

Tritium is formed in thermal nuclear reactors both by neutron activation of elements such as deuterium and lithium and by ternary fission in the fuel. It is a weak beta-emitter with a short half-life, 12.3 years, and its radiological significance in reactor discharges is very low. In heavy-water-cooled and -moderated reactors, such as the SRS reactors, the tritium concentration in the moderator is sufficiently high to cause a potential hazard to operators, so research and development programs have been carried out on processes to remove the tritium. Detritiation of light water has also been the subject of major R D efforts world-wide, because reprocessing operations can generate significant quantities of tritium in liquid waste, and high concentrations of tritium may arise in some aqueous streams in future fusion reactors. This paper presents a review of some of the methods that have been proposed, studied, and developed for removal of tritium from light and heavy water, along with some new concepts for aqueous detritiation directly from liquid oxide (HTO) bearing feed streams

Product consistency leach tests of Savannah River Site radioactive waste glasses

The Product Consistency Test (PCT) is a glass leach test that was developed at the Savannah River Site (SRS) to routinely confirm the durability of nuclear waste glasses that will be produced in the Defense Waste Processing Facility. The PCT is a 7 day, crushed glass leach test in deionized water at 90{degree}C. Final leachates are filtered and acidified prior to analysis. To demonstrate the reproducibility of the PCT when performed remotely, SRS and Argonne National Laboratory have performed the PCT on samples of two radioactive glasses. The tests were also performed to compare the releases of the radionuclides with the major nonradioactive glass components and to determine if radiation from the glass was affecting the results of the PCT. The test was performed in triplicate at each laboratory. For the major soluble elements, B, Li, Na, and Si, in the glass, each investigator obtained relative precisions in the range 2--5% in the triplicate tests. This range indicates good precision for the PCT when performed remotely with master slave manipulators in a shielded cell environment

Selection and cultivation of final vegetative cover for closed waste sites at the Savannah River Site, SC

Low-level, hazardous, and mixed waste disposal sites normally require some form of plant material to prevent erosion of the final closure cap. Waste disposal sites are closed and capped in a complex scientific manner to minimize water infiltration and percolation into and through the waste material. Turf type grasses are currently being used as a vegetative cover for most sites. Consequently, the sites require periodic mowing and other expensive annual maintenance practices. The purpose of this five year study was to evaluate alternative plant material for use on wastes sites that is quickly and easily established and economically maintained, retards water infiltration, provides maximum year-round evapotranspiration, is ecologically acceptable and does not harm the closure cap. The results of the study are described in this report and suggest that two species of bamboo (Phyllostachys bissetii and P. rubromarainata) can be utilized to provide long lived, low maintenance, climax vegetation for the waste sites. These large species of bamboo will also reduce the probability of intrusion by humans, animals and deeply rooted plant species

Spectroscopic probes of the structure of hydrous uranium oxide precursors to UO sub 2 ceramic fuel

Fourier Transform infrared spectroscopy, x-ray powder diffraction and thermal analysis show that one example of ammonium diuranate'' observed as an intermediate in the U(VI) sol-gel process is a layered hydrous uranium oxide with a proposed structural formula of (NH){sub 4}{sub 2}((UO{sub 2}){sub 8}O{sub 4}(OH){sub 10}){center dot}8H{sub 2}O, an ammonium ion intercalate. Examples of polyamine intercalation compounds hydrous uranium oxide are also given

A methodology to model local nonlinearities in a slender reinforced concrete member subjected to seismic deformations

A methodology is proposed for modeling local nonlinear behavior of slender reinforced concrete members. The nonlinearity is modeled by two orthogonal assemblages of nonlinear truss elements representing the nonlinear behavior of concrete and steel reinforcement. The trusses represent narrow strips of concrete to closely calculate the section neutral axis. This modeling procedure is computationally very efficient for seismic nonlinear dynamic analysis. Such a model is used to evaluate a critical column framing a door opening of a nuclear exhaust stack building subjected to seismic motions

Re-evaluation of Savannah River reactor transient reactivity coefficient tests: The effect of delayed neutron constants and spatial variations

Transient reactivity test conducted in one of the Savannah River production reactors in 1962 have been re-evaluated. A significantly lower (more negative) coolant temperature coefficient is now ascribed to that test; {minus}1 pcm/Deg-C vs the previously obtained +2 pcm/Deg-C. The change from the previous value is because of revisions to delayed neutron constants and accounting for spatial effects. The new value is in reasonable agreement with the currently calculated value of {minus}2 pcm/Deg-C, considering measurements and calculational uncertainties. Therefore, we conclude that the current analytic models for physics and transient analysis are fully consistent with the 1962 test observation, and that there is no basis for assigning a calculational bias or increasing uncertainty allowances. 2 refs