Objectives conservative assumptions

The plant design obj ective is 60 years without the planned replacement of the reactor vessel, which itself has a 60- year design objective based on conservative assumptions. The design provides for the replace-ability of other major components, including the steam generators. 

The OASIS code has been used for the thermal hydraulics analyses. A large number of events were analysed. The objective of these studies was to identify the worst-case scenario. Therefore, rupture position, rupture time, and break size spectra must be analysed. Currently, the detailed thermal hydraulics analysis for the primary coolant pipe break accident as a function of the break position is being performed. This study is based on conservative assumptions, as required for Category 4 DBE analyses. The main results of this analysis are the core inlet and outlet temperatures, the break flow rate, the IHX inlet and outlet temperatures, as well as the and clad temperature distribution. The results of the calculations show that the hotspot temperatures for the cladding and for the coolant are below the design safety limits (DSL). These temperatures are lower than the sodium boiling temperature. The regulator accepted the methods applied, as well as the results of the analysis. 

Cosmology is based on the assumption that matter in the early stage of evolution of the Universe was of extraordinarily high density. From this, in 1966, Ya.B. and I. D. Novikov came to the conclusion that the generation of small black holes was possible in the early stages of evolution. Finally, it was shown in a very general form that the collapse of any nonsymmetrical object leads to the creation of an external observable metric which is wholly determined by conserved quantities [55] (with A. G. Doroshkevich and I. D. Novikov). 

This is half of the story. If the old assumption about the electron made it an object that moves in a circle, quantum mechanics replaces the object with its observable properties, described in the form of mathematical functions. There is no longer an object , except as lodged in the conservative mind of the physicist. Whatever we are looking at here doesn t move , either, in any detectable sense. It remains to ask, what concept arises to take the place of the circle , and how must it relate to the new notions of what an electron ought to be ... 

Where elemental concentrations are higher in indoor dust than in soil and exterior dust, it may be expected that indoor sources, including construction materials, paint, furnishings and other consumer products, are an important influence. Relative contributions of indoor sources of metals are difficult to quantify. Harrison (1979) reported that abrasion of household objects causes deposition of metal particles in house dust, but observed that the majority of these particles are not readily recognizable by microscopy. Elements such as Al, Ba, Si, and Ti have been proposed as conservative tracers to estimate the relative contribution of soil to house dust (Trowbridge and Burmaster, 1997 Calabrese and Stanek, 1992), but these estimates are based on the assumption... 

The key point is the conservation of the total number of entities for a pair of objects. It translates Pauli s exclusion principle in the following manner The constancy of the total number of objects can be viewed as a fixed number of available sites or allowed energy states. A site (or energy state) can contain one electron or one hole but not both (no electron-hole pairs and no annihilation), because, if we could put more than one electron or hole on one site, the conservation would not be respected. This relies on the assumption that the conservation must... 

In this chapter we have considered the derivation of dynamic models from first principles, especially conservation equations. Model development is an art as well as a science. It requires making assumptions and simplifications that are consistent with the modeling objectives and the end use of the model. A systematic approach for developing dynamic models is summarized in Table 2.1. This approach has been illustrated by deriving models for representative processes. Although these illustrative examples are rather simple, they demonstrate fundamental concepts that are also valid... 

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