Design Targets

As the coolant temperature exceeds the pseudocritical temperature, the specific heat capacity decreases. This implies that for an average core outlet temperature of 500 C, the local coolant temperature may be significantly higher than that. The local increase of the coolant temperature may cause an excess heat up of the fuel rod cladding and may cause fuel failures. Therefore, the coolant outlet temperature distribution should be as uniform as possible to achieve a high average outlet temperature. 

The coolant temperature depends on its flow rate and the heat flux from the fuel rods. Therefore, flattening the core radial power distribution is effective in flattening the coolant outlet temperature distribution. The outlet temperature distribution can also be flattened by adjusting the coolant flow rate to each fuel assembly, so that the power to flow rate ratio is kept the same for all fuel assemblies. The flow rate can be adjusted by designing appropriate pressure drops at the entrance of each fuel assembly using an inlet orifice. 

The orifices in BWRs are mainly used for improving the core thermal-hydraulic stabilities. Generally, the BWR channel stability improves when the pressure drops and inertia in the single-phase flow region are increased. This is why inlet orifices are used in BWRs. For LMFBRs, inlet orifices are used to control the coolant flow rate to the fuel assemblies to effectively cool the fuel. 

The primal reason of orifices use for the Super LWR is for effectively cooling the fuel. This is the same as the role of the orifices in LMFBRs. However, the former orifices are also important for attaining thermal-hydrauhc stabilities, especially during the plant startup (see Chap. 5 for more details). 

The power distributions should also be kept flat for reducing the MLHGR. The MLHGR needs to be kept as low as possible to reduce the fuel temperature. From the viewpoint of reducing the fuel temperature, large power peaks near the outlet of the core should also be prevented. 

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Sinee the poorest performanee of the assembly distribution would oeeur when shifted, Cpk values rather than Cp values are better design targets. The Cp value ean be used as a target for the assembly based on the severity of applieation and minimum failure eost of 0.01% of the total produet eost as determined by the Conformability Map. If only eapable solutions are to be generated, whieh have a minimum proeess eapability index of Cp =1.33 (or 30 ppm) for both eomponent and assembly distributions, then the number of eomponents in the assembly staek ean be as low as three using the proposed statistieal model (Harry and Stewart, 1988). The overall requirement is... 

In order to examine whether this sequence gave a fold similar to the template, the corresponding peptide was synthesized and its structure experimentally determined by NMR methods. The result is shown in Figure 17.15 and compared to the design target whose main chain conformation is identical to that of the Zif 268 template. The folds are remarkably similar even though there are some differences in the loop region between the two p strands. The core of the molecule, which comprises seven hydrophobic side chains, is well-ordered whereas the termini are disordered. The root mean square deviation of the main chain atoms are 2.0 A for residues 3 to 26 and 1.0 A for residues 8 to 26. 

Wajant H, Gerspach J, Pfizenmaier K (2005) Tumor therapeutics by design targeting and activation of death receptors. Cytokine Growth Factor Rev 16 55-76... 

Determine a set of pure component properties (design targets) of the solvent under replacement (specify the goal values for the properties together with upper and lower bounds)... 

Rowinsky EK. The pursuit of optimal outcomes in cancer therapy in a new age of rationally designed target-based anticancer agents. Drugs 2000 60 1-14 discussion 41 —42. 

PROTEINS AS DRUGS AND DRUG DESIGN TARGETS ENZYMES... 

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