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Probabilistic risk assessment of the modular HTGR plant. Revision 1

Description: A preliminary probabilistic risk assessment (PRA) has been performed for the modular HTGR (MHTGR). This PRA is preliminary in the context that although it updates the PRA issued earlier to include a wider spectrum of events for Licensing Basis Events (LBE) selection, the final version will not be issued until later. The primary function of the assessment was to assure compliance with the NRC interim safety goals imposed by the top-level regulatory criteria, and utility/user requirements regarding public evacuation or sheltering. In addition, the assessment provides a basis for designer feedback regarding reliability allocations and barrier retention requirements as well as providing a basis for the selection of licensing basis events (LBEs) and the safety classification of structures, systems, and components. The assessment demonstrates that both the NRC interim safety goals and utility/user imposed sheltering/evacuation requirements are satisfied. Moreover, it is not anticipated that design changes introduced will jeopardize compliance with the interim safety goals or utility/user requirements. 61 refs., 48 figs., 24 tabs.
Date: June 1, 1986
Creator: Everline, C.J.; Bellis, E.A. & Vasquez, J.
Partner: UNT Libraries Government Documents Department

Environmental Analysis of Endocrine Disrupting Effects from Hydrocarbon Contaminants in the Ecosystem

Description: This annual report summarizes the progress of three years of a three-year grant awarded to the Center for Bioenvironmental Research (CBR) at Tulane and Xavier Universities. The objective of this project is to determine how environmental contaminants, namely hydrocarbons, can act as hormones or anti-hormones in different species present in aquatic ecosystems. The three major areas of research include (1) a biotechnology based screening system to identify potential hormone mimics and antagonists; (2) an animal screening system to identify biomarkers of endocrine effects; and (3) a literature review to identify compounds at various DOE sites that are potential endocrine disruptors. Species of particular focus in this study are those which can serve as sentinel species (e.g., amphibians) and, thus, provide early warning signals for more widespread impacts on an ecosystem and its wildlife and human inhabitants. The focus of the literature research was to provide an analysis of the contaminants located on or around various Department of Energy (DOE) sites that are or have the potential to function as endocrine disruptors and to correlate the need for studying endocrine disruptors to DOE's programmatic needs. Previous research within the Center for Bioenvironmental Research at Tulane and Xavier Universities has focused on understanding the effects of environmental agents on the human and wildlife health and disease. In particular this research has focused on how exogenous agents can function to mimic or disrupt normal endocrine signaling, i.e. estrogen, thyroid within various systems from whole animal studies with fish, amphibians and insects to human cancer cell lines. Significant work has focused on the estrogenic and anti-estrogenic action of both synthetic organochlorine chemicals and naturally produced phytochemicals. Recent projects have extended these research objectives to examination of these environmental agents on the symbiotic relationship between nitrogen fixing rhizobial bacteria and leguminous plants. This research will ...
Date: June 1, 2000
Creator: McLachlan, John A.
Partner: UNT Libraries Government Documents Department

300-Area accident analysis for Emergency Planning Zones

Description: The Department of Energy has requested SRL assistance in developing offsite Emergency Planning Zones (EPZs) for the Savannah River Plant, based on projected dose consequences of atmospheric releases of radioactivity from potential credible accidents in the SRP operating areas. This memorandum presents the assessment of the offsite doses via the plume exposure pathway from the 300-Area potential accidents. 8 refs., 3 tabs.
Date: June 27, 1983
Creator: Pillinger, W.L.
Partner: UNT Libraries Government Documents Department

Health effects in women exposed to low levels of ionizing radiation

Description: There are three delayed health effects of radiation which appear at the present time to have importance to women in radiation protection. These are: (1) the probability of cancer-induction at low doses and low-dose rates; (2) the consideration of those cancers in women, notably the breast and the thyroid, attributable to radiation exposure; and (3) the probability of induction of developmental abnormalities in the newborn following low-dose exposure in utero. The bases for the concern over these effects are discussed. (ACR)
Date: June 1, 1982
Creator: Fabrikant, J.I.
Partner: UNT Libraries Government Documents Department

Assessment of /sup 99/Tc releases to the atmosphere: a plea for applied research. [Dose to man through food chain concentration]

Description: Recent experimental data suggest that the concentration factor for uptake of /sup 99/Tc by vegetation from soils may be two to three orders of magnitude higher than the 0.25 value currently being used in radiological assessments. Following a survey of the literature, a concentration factor of 50 was applied to evaluate the dose from a 1.0 Ci/year release to the atmosphere by a hypothetical uranium enrichment facility. Doses to the GI tract and thyroid of an adult living 1600 m from the facility were 18 millirems and 80 millirems, respectively. These doses are delivered entirely through transport of /sup 99/Tc through food chain pathways. This assessment indicates a potential for /sup 99/Tc exposures to exceed recently proposed standards of the U.S. Environmental Protection Agency in 40 CFR 190. The previously assumed concentration factor of 0.25 would have produced corresponding doses of 0.13 millirem to the GI tract and 0.57 millirem to the thyroid. The results of this analysis demonstrate the need for additional research on the environmental behavior and dosimetry of /sup 99/Tc. In particular, data are needed to elucidate the retention of /sup 99/Tc in soils and the uptake of /sup 99/Tc by edible vegetation in field studies of chronic exposure conditions. Data on the uptake and retention of /sup 99/Tc in humans are also necessary to improve the reliability of dose conversion factors for specific organs and various age groups.
Date: June 1, 1978
Creator: Till, J.E.; Hoffman, F.O. & Dunning, D.E. Jr.
Partner: UNT Libraries Government Documents Department

Milk production and distribution in low-dose counties for the Hanford Thyroid Disease Study

Description: This report identifies sources of milk consumed by residents of Ferry, Okanogan, and Stevens Counties. This information will be used by the Hanford thyroid Disease Study to determine whether thyroid disease has been increased among people exposed to past iodine--131 emissions from Hanford Site Facilities.
Date: June 1, 1992
Creator: Schimmel, J.G. (Washington State Univ., Pullman, WA (United States). Social and Economic Sciences Research Center) & Beck, D.M. (Pacific Northwest Lab., Richland, WA (United States))
Partner: UNT Libraries Government Documents Department

HEDR model validation plan. Hanford Environmental Dose Reconstruction Project

Description: The Hanford Environmental Dose Reconstruction (HEDR) Project has developed a set of computational ``tools`` for estimating the possible radiation dose that individuals may have received from past Hanford Site operations. This document describes the planned activities to ``validate`` these tools. In the sense of the HEDR Project, ``validation`` is a process carried out by comparing computational model predictions with field observations and experimental measurements that are independent of those used to develop the model.
Date: June 1, 1993
Creator: Napier, B. A.; Gilbert, R. O.; Simpson, J. C.; Ramsdell, J. V. Jr.; Thiede, M. E. & Walters, W. H.
Partner: UNT Libraries Government Documents Department

Milk production and distribution in low-dose counties for the Hanford Thyroid Disease Study. Hanford Environmental Dose Reconstruction Project

Description: This report identifies sources of milk consumed by residents of Ferry, Okanogan, and Stevens Counties. This information will be used by the Hanford thyroid Disease Study to determine whether thyroid disease has been increased among people exposed to past iodine--131 emissions from Hanford Site Facilities.
Date: June 1, 1992
Creator: Schimmel, J. G. & Beck, D. M.
Partner: UNT Libraries Government Documents Department