Recent safety assessment studies have identified the short-term station blackout accident sequence as an important contributor to the overall plant risk of currently operating boiling water reactors (BWRs). In this hypothetical scenario, the loss of all off- and on-site alternating-current power is coupled with the loss of the capability for water injection to the reactor vessel (caused by, for example, the independent failure of the high-pressure core injection and reactor coolant inventory control). At present, the outcome of this accident sequence is not well understood, primarily due to uncertainty in the relevant core melt progression path. Of interest in this study is the core-structure heatup and subsequent melt relocation leading to the possible formation of core blockages. The results of one-dimensional heat transfer analysis and three-dimensional heat transfer and material relocation modeling are summarized.
The Severe Core Damage Analysis Package (SCDAP) computer code is being developed at the Idaho National Engineering Laboratory under the sponsorship of the US Nuclear Regulatory Commission, Office of Nuclear Regulatory Research. SCDAP models the progression of light water reactor core damage including core heatup, core disruption, debris formation, debris heatup, and debris melting. SCDAP is being used to help identify and understand the phenomena that control core behavior during a severe accident, to help quantify uncertainties in risk assessment analysis, and to support planning and interpretation of severe fuel damage experiments and data.
ABSTRACTUNC-45A is an ubiquitously expressed protein highly conserved throughout evolution. Most of what we currently know about UNC-45A pertains to its role as a regulator of the actomyosin system...