Control support structure expansion

The KALIMER design highly emphasizes inherent safety, which maintains the core power reactivity coefficient negative during all modes of plant status and under accidental conditions as well. The reactivity feedback mechanisms consist of Doppler, thermal expansion of the fuel and coolant, thermal bowing of the core, thermal expansion of the core structure and core support structure, and thermal expansion of the control rod driveline. These effects result from either the physics laws, or both the physics laws and core design. 

A complicating factor for both the structure and the thermal control subsystems would be the differential expansion between the primary support structure and the reactor coolant segment. Heat rejection elements would either need to be structurally un-coupled from the hot leg piping (eg, rely on radiative transfer) or move with the hot leg piping (eg, a floating platform that moves with the piping). These considerations would need to be a primary consideration as the structure and thermal control subsystems are developed. 

During the selection of the proper materials to be used for protection, several characteristics of each material would be rated to help narrow the decision. The minimum characteristics that should be evaluated for these materials are ability to withstand environmental and plant produced radiation, coefficient of thermal expansion, density, electrical resistivity and conductance to control electrostatic discharge, material chemistry ar d composition, operational temperature range, resilience, specific heat, strength, stiffness, thermal conductivity, thermal radiation absorptivity, thermal radiation emissivity, the ability to fasten the material to the support structure and/or the components themselves, and the compatibility between the protecting material and material to which it would be fastened... 

The deposition of a suitable catalyst in the intimate body of the above-described filters is controlled primarily by the structure of the filter itself, but it is also influenced by the nature of its constituent material. In fact, shear stresses may arise at the interface between this material and the deposited catalyst, owing to thermal expansion mismatch between the two phases. Since most catalyst supports are based on inorganic oxides, this problem would be particularly serious for metal-based filters, owing to their much higher thermal expansion coefficients. However, in some metal alloys, such as the FeCrAlloy, a thin surface layer of a metal oxide (e.g., ALOO is formed at high temperatures, which improves their thermal resistance and allows a proper basis for catalyst anchoring. 

The phenylpropanoid pathway (Fig. 3.1) is responsible for the production of many natural products that are of interest in the context of plant growth and development, human health, and ecology. For example, flavonoids are necessary for pollen viability in maize and petunia, and have been suggested to play a role in directed auxin transport. Flavonoids and sinapate esters have been found to be important UV-protectants in many species, including Arabidopsis. Furthermore, wall-bound phenolics are thought to impart control over cell wall expansion, and hydroxycinnamic acids are an important structural component of the hydrophobic barrier polymer suberin. Finally, lignin is a phenylpropanoid polymer ubiquitous in higher plants, which is necessary for mechanical support and water transport. " ... 

The external case of the rocket motor supports the mechanically and thermally induced stresses, which are due to internal gas pressure, vibration, acceleration, thrust vector control, and differential thermal expansion of component materials. To accommodate these factors, the structural material should have high strength, adequate modulus, and resistance to buckling. Either a continuous glass filament wound epoxy plastic or a high temperature metal (steel, titanium, or aluminum) case serves as the exterior structural member. 

Supports behavioral transformations, primarily to improve the efficiency of the control structure constant folding, common subexpression elimination, dead procedure elimination, inline expansion and formation of procedures, code motion into and out of the branches of decoding operations, and loop unrolling. 

In addition to accommodation of thermal expansion, the secondary structure would need to perform other functions such as support other module components (cables, sensors, thermal control and micrometeor protection elements, etc), interface to hot components, provide dynamic isolation during operation, etc. Some of the challenges include ... 

---