The integral code ASTEC (Accident Source Term Evaluation Code) commonly developed by IRSN and GRS is a fast running programme, which allows the calculation of entire sequences of severe accidents (SA) in light water reactors from the initiating event up to the release of fission products into the environment, thereby covering all important in-vessel and containment phenomena. Thus, the main fields of ASTEC application are intended to be accident sequence studies, uncertainty and sensitivity studies, probabilistic safety analysis level 2 studies as well as support to experiments. The modular structure of ASTEC allows running each module independently and separately, e.g. for separate effects analyses, as well as a combination of multiple modules for coupled effects testing and integral analyses. Among activities concentrating on the validation of individual ASTEC modules describing specific phenomena, the applicability to reactor cases marks an important step in the development of the code. Feasibility studies on plant applications have been performed for several reactor types such as the German Konvoi PWR 1300, the French PWR 900, and the Russian VVER-1000 and −440 with sequences like station blackout, small- or medium-break loss-of-coolant accident, and loss-of-feedwater transients. Subject of this paper is a short overview on the ASTEC code system and its current status with view to the application to severe accidents sequences at several PWRs, exemplified by selected calculations.
Since 2000 the Wisconsin Department of Commerce had classified restaurant wastewater as high strength waste, and is required to have advanced treatment prior to soil dispersal. In 2005, design and construction of the onsite treatment system and the restaurant occurred simultaneously in an unsewered area near growing communities. The restaurant opened for business in late July and the wastewater system began to operate in August, 2005.Random samplings from various unit processes occurred over the following 3.5 years. Available data showed organic loading to the primary biological process which averaged 163 % of design, while flow averaged 94 % of design.This study examines a relatively new fixed film technology that had been chosen as the primary biological treatment process. The SMART-Treat™ moving media process had been downsized from larger municipal & industrial applications. The unique Combined Fixed Activated Sludge (CFAS) features designed into the flow path provided hybrid process performance and delivered good quality effluent to downstream processes in overloaded conditions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.