Impact on plant design

The report presents the findings from the analysis of the RCP failures. Estimates of the annual frequency for the spectrum of leak rates induced by RCP seal failures and their impact on plant safety (contribution to coremelt frequency) are made. The safety impact of smaller RCP seal leaks was assessed qualitatively, whereas for leaks above the normal makeup capacity, formal PRA methodologies were applied. Also included are the life distribution of RCP seals and the conditional leak rate distributions, given a RCP seal failure the contribution of various root causes and estimates for the dependency factors and the failure intensity for the different combinations of pump designers and plant vendors. 

A. Pinto and P.L. Rogerson, "IMPACT OF HIGH FUEL COST ON PLANT DESIGN Chemical Engineering Progress, July,... 

The AHj. does however have an important bearing on plant design and costs. An endothermic reaction requires energy to drive it, which is an additional cost. The energy has to be supplied efficiently to the reaction section of the plant, which has a significant impact on reactor design and cost. 

In the case of an exothermic reaction the energy generated needs to be efficiently removed otherwise a runaway reaction could occur with potentially disastrous consequences. The catalyst itself may also be sensitive to even small increases in reaction temperature which may shorten its lifetime or result in a loss in reaction selectivity. The energy generated in an exothermic reaction may be recovered, often as steam, and used as a cost credit that energy has to be efficiently removed from the reaction section of the plant, again with impact on reactor design and cost. 

Catalyst deactivation has such an impact on the design and operation of plants that studies along the approach outlined here are fully justified. They should be an integrated part of the process development. 

Inspection and maintenance must be considered throughout the design. One of the major conclusions from the operation of large fast reactors is that inspection requirements often have major negative impacts on plant availability. 

The NRC concluded in NUREG-1233 (Reference 4) that these revisions would reflect the current state-of-the-art in seismic design in the licensing process. Implementation of the SRP revisions is expected to contribute to a more uniform and consistent licensing process and is not expected to have significant impact on recently designed plants. 

The choice about the response to diagnostic alarms is related to risk tolerance. That being the case, at least from a conceptual point of view, the choice should be made by the owner/operator to ensure a consistent approach. When looking at specific processes, personnel need to provide their input along with those who are knowledgeable about process hazards, human response, the plant safety culture, and design issues. These decisions have a direct impact on plant cost and safety. 

The pressure drop through a CBA unit depends to a large extent on the system design. As an add-on to an existing two reactor Claus unit, the addition of two CBA converters, a condenser, and the switching valves can add I to 3 psi to the overall plant pressure drop. However, converting an existing three-converter Claus unit to a three-converter CBA unit will have minimal impact on plant pressure drop. 

Preliminary concept and design efforts were terminated prior to obtaining formal vendor input on whether this value was practical or attainable for any or all valve applications. Initial values for valve loss coefficients, k-factors, were calculated in the following subsections. This work was performed in support of heat balance development, Section 6. For loss coefficient impact on plant heat balance, refer to the heat balance section. 

There are a large number of contingencies that influence the design of a particular PRV, but may have no impact on the design of the overall plant. The controlling contingencies need to be established and reported for the following situations ... 

For by-product coke ovens, it is general practice to blend two or more types of coals that have complimentary technical as well as economic characteristics. Because most by-product coke plants are located near the large industrial users of the coke and by-products, coals usually have to be transported from the coal mines to the coke plants. Thus coal blends are designed on integration of coke quaUty needs, by-product quaUty needs, coal costs, transportation costs, impacts of productivity, and impacts on the coke ovens themselves. The physical behavior of coal blends during coking can damage coke ovens. 

Clearly, the turboexpander is one of several key components in a process plant and liquid production is related to the performance of all components of the plant, not the turboexpander alone. It has previously been assumed that changes in the normal design conditions of turboexpanders have not adversely affected other equipment in the plant because adverse impact on other equipment, if any, would further reduce liquid production. This simplifies the assumptions, but does not affect the general validity of the findings. 

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