4-year operating cycle

A 4-year operating cycle means that refueling no longer has to take place every 18 months. The main benefit is capacity factor increase more money for the generator and... 

The AFPR concept of 100 MW(e) is generally similar to the VKR-MT in overall design approach, but suggests the use of continuous in-vessel transport of micro fuel elements to achieve a 36-year operation cycle without refuelling. The concept is in two versions, a BWR and a direct flow system with superheated steam at core outlet. 

The mass flow of UO2 is 207 kg/year/MW(th) based on a 10-year operating cycle. 

Simplified design that eliminates certain equipment items and provides for a 5-year operating cycle, resulting in reduced maintenance requirements ... 

Elimination of the fuel pool and refueling machine (for a 15-year operation cycle). 

The core of a standard NPP of 1000 MWg, such as the previously mentioned reactor, contains approximately 72 ton of low-enriched uranium. According to this composition of SNF, in a yearly operating cycle (refueling annually with one-third replaced, ie, 24 ton U/year), the spent fuel contains approximately 23 ton uranium (including 240 kg U), 240 kg Pu, and approximately 1 ton of fission products and transuranium elements other than Pu. Thus there are approximately 36 kg MAs (ie, Np, Am, and Cm, equivalent to 0.15% of the total SNF). 

The dehydrogenation of 2-butanol is conducted in a multitube vapor-phase reactor over a zinc oxide (20—23), copper (24—27), or brass (28) catalyst, at temperatures of 250—400°C, and pressures slightly above atmospheric. The reaction is endothermic and heat is suppHed from a heat-transfer fluid on the shell side of the reactor. A typical process flow sheet is shown in Figure 1 (29). Catalyst life is three to five years operating in three to six month cycles between oxidative reactivations (30). Catalyst life is impaired by exposure to water, butene oligomers, and di-j -butyl ether (27). 

Assuming a 480-ton/day treatment rate, the estimated life-cycle cost for a full-scale treatment is approximately 160 per ton of dry soil processed (D13753L, p. 2). This estimate includes fixed capital investment and operating costs based on a 70% utilization factor for plant operations over a period of 17 years. Operating cost estimates (included iu the life-cycle cost estimate) include an inflation rate of 5% per year (D13753L, pp. 32-34). 

The PCO system can operate basically unattended, resulting in extremely low operation and maintenance costs (D12104Q, p. 25). Over a 10-year life cycle, the Los Alamos National Laboratory estimates that operating costs will make up only 17% of total costs. Capital costs account for 43%, utilities for 14%, and maintenance for 26% of the total costs (D12104Q, p. 26). 

For the purposes of this estimate, it was assumed that the TVS unit would operate 24 hr per day. It was also assumed that the costs of a 1.6 million equipment upgrade would be spread out over a 10-year life cycle, and that the unit would be operating at a feed rate of 50 to 100 kg/hr (D179479, p. 4-22). 

Rankine Cycle. The sleam-Rankine cycle employing steam turbines has been the mainstay of utility thermal electric power generation for many years. The cycle, as developed over the years, is sophisticated and efficient. The equipment is dependable and readily available. A typical cycle (Fig. 21) uses superheat, reheat, and regeneration. Heat exchange between flue gas and inlet air adds several percentage points to boiler efficiency in fossil-fueled plants. Modern steam Rankine systems operate at a cycle top temperature of about 800 K with efficiencies of about 40%. All characteristics of this cycle are well suited to use in solar plants. 

The primary energy payback time is 3.1 years, and the GHG emissions payback time is 3.1 years. With a thirty year life cycle for all system components and the replacement of gasoline ICE vehicles with H2 FCVs, the payback time estimates translate into vehicle operation with 27 years of fossil fuel free energy use and zero GHG emissions. The sensitivity results indicate that a + 25% change in all life cycle estimation parameters change the primary energy payback time by + 0.80 years and the GHG emissions payback time by + 0.81 years. 

The catalysts are non-corrosive and operate at mild conditions, allowing for all carbon-steel construction. The reactors can be designed for 2-6 year catalyst cycle length, and the catalyst is fully regenerable. The process does not produce any hazardous effluent. 

For many years mechanical pressing was the only method employed. Alternative and/or auxiliary methods were developed, however, because the need to ensure continuous operating cycles, the high labour costs, changes in raw materials, unsatisfactory yields and other factors made it essential to find new approaches in juice extraction technology. 

Currently, PC hardware has a life cycle of less than 2 years. Operating software typically has a support hfe of 5 years, then a further 2 years of reduced support before the operating system is no longer supported by the supplier. Management of the IPC upgrade protects the system investment from threats to the system s validated status, serious maintenance problems, and potentially costly fast-track projects. 

Total annual cost = operating and shutdown costs/cycle X cycles/year + annual fixed costs Annual production = (production/cycle) (cycles/year) operating + shutdown time used/year... 

Experimental results show the high stability of INT-R1 catalyst when processing feedstocks with high metal, Conradson Carbon, and asphaltene content. Operating cycles of a least six months were demonstrated at bench scale using feedstocks with 400 ppm metals, 8 to 10 wt% Conradson Carbon and 8 %wt asphaltenes. Expected INT-R1 catalyst life with lighter feedstocks shows the feasibility of reaching a stable operation for more than one year with up to 100% metal retention on the catalyst. 

The second process, the Unrestricted Operations Maintenance Requirements Card (URO MRC) program, involves periodic inspections and tests of critical items to ensure they have not degraded to an unacceptable level due to use, age, or environment. In fact, URO MRC did not originate with SUBSAFE, but was developed to extend the operating cycle of USS Queenflsh by one year in 1969. It now provides the technical basis for continued unrestricted operation of submarines to test depth. 

The overhaul period stipulated in Ihe Project is 1 year with an allowance for transportation time. The Project provides for two overhauls and three operating cycles. 

The steamcracker of ethane in Example 1 has an operating cycle of 300 days a year. The conversion per pass is 60%. The mass composition of the hydrocarbon products withdrawn as follows 80% C2H4 1.4% C3H 4.8% C4H3 0.2% petrol 13.6% fuel gases. Calculate the mass flow rates of the supply, of the withdrawn products and of the recycling of the unit, and the selectivities of the alkenes. 

---