Operating life

Extend the safe useful operation life of major HT/HP power plant items, subject to time-dependent creep and thermal fatigue damage, with benefits in terms of delayed costs for component replacement. 

Other wastes are expected to arise from the decontarnination and decommissioning of existing nuclear faciHties. These include reactors at the time of life extension or at the end of their operating life. Whereas technologies are available for waste disposal, as of this writing (ca 1995) there is much pubHc resistance to the estabHshment of disposal faciHties. 

Another possibiUty is the net payout fraction (NPE), defined as the ratio of the NPT to the operating life of the venture. This is the fraction of the expected operating lifetime needed to recover the discounted investment. 

Equation (9-245) shows that in this particular case the fixed-capital cost per unit of input energy CpJW) must not exceed 160,000 (GJh" )" or 576 per kilowatt, to have a 1-year payback period if the heat pump is operational for 8000 h/year. For this case the corresponding value of y is about 0.12 for a heat pump with an operating life of 10 years purchased with money borrowed at a 10 percent rate of interest. 

Other demands (compatibility with existing systems, type of load, compactness, level of automatization, operating life, possibihty to use process fluid as refrigerant)... 

Soft starting minimizes the starting mechanical and thermal stresses/shocks on the machine and the motor. It results in reduced maintenance cost, fewer breakdowns and hence longer operating life for both. Reduced starting current is an added advantage. 

I Operating basis earthquake (OBE) test This is defined by an earthquake that may be expected to occur during the operating life of the object for which... 

One will appreciate that such tests are no guarantee of the minimum life of a capacitor unit. Moreover, it is not expected that such tests can predict the future of the capacitor units. They can, at best, suggest the compliance of the test requirements which should ensure a reasonably prolonged operating life of the capacitors, as envisaged. These tests do provide feedback to the manufacturer on the t uality of the dielectric and the process of insulation adopted and if iiny improvements are required. 

There are a variety of ways to express absolute QRA results. Absolute frequency results are estimates of the statistical likelihood of an accident occurring. Table 3 contains examples of typical statements of absolute frequency estimates. These estimates for complex system failures are usually synthesized using basic equipment failure and operator error data. Depending upon the availability, specificity, and quality of failure data, the estimates may have considerable statistical uncertainty (e.g., factors of 10 or more because of uncertainties in the input data alone). When reporting single-point estimates or best estimates of the expected frequency of rare events (i.e., events not expected to occur within the operating life of a plant), analysts sometimes provide a measure of the sensitivity of the results arising from data uncertainties. 

Mechanical seal manufacturers design their products to last 5 to 10 years. The majority of seals are designed for 40,000 hours of operating life. There are 8,760 hours in a year. This is approximately 5 years, running a pump at 24 hours per day, and 15 years for a pump running at 8 hours per clay. 

The troubleshooting proeess—how easy it is to troubleshoot a maehine, how often it needs to be done, and so forth—depends largely on the type of maintenanee philosophy applied during the maehine s operational life. This baste philosophy affeets how often the maehine must be monitored. 

The Larson-Miller parameters are plotted in Figure 11-4 for the speeified turbine blade alloys. A comparison of A-286 and Udimet 700 alloy curves reveals the difference in capabilities. The operational life (hrs) of the alloys can be compared for similar stress and temperature conditions. 

Depreciation. This is a noncash cost that accumulates money to rebuild the facilities after the project life is over. There are usually two depreciation rates. One is the corporation s book depreciation, which reflects the expected operating life of the project. The other is the tax depreciation, which is usually the maximum rate allowed by tax laws. To be correct, the tax depreciation should now be called Accelerated Capital Cost Recovery System (ACRS). 

First, the designer should choose the type of rectification technology that is most appropriate for the application. The choice is whether to use passive rectification in which semiconductor rectifiers are used or synchronous recification in which power MOSFE B are placed in parallel with a smaller passive rectifier. Synchronous rectifiers are typically used in battery operated portable products where the added efficiency, usually an added two to eight percent, is important to extend the operating life of the battery or in applications where heat is important. In today s switching power supplies, passive rectifiers can dissipate 40 to 60 percent of the total losses within the power supply. Synchronous rectifiers affect only the conduction loss, which can be reduced by as much as 90 percent. 

The input and output filter eapaeitors do not eontribute a signifieant souree of loss to a switehing power supply, although they ean greatly affeet the operating life of the supply. The input eapaeitor(s), if ehosen ineorreetly, ean make the supply appear like it is operating less effieiently than it aetually is. 

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