Fuel recovery

Company Midwest Fuel Recovery Plant Technical Study Report (July 5,1974)... 

Simple representations of three fuel cell based heat and fuel recovery cycles are shown in Figures 9-12, 9-13, and 9-16. 

The results of the performance calculations are summarized in Table 9-24. The efficiency of the overall power system, work output divided by the lower heating value (LHV) of the CH4 fuel, is increased from 57% for the fuel cell alone to 82% for the overall system with a 30 F difference in the recuperative exchanger and to 76% for an 80 F difference. This regenerative Brayton cycle heat rejection and heat-fuel recovery arrangement is perhaps the simplest approach to heat recovery. It makes minimal demands on fuel cell heat removal and gas turbine arrangements, has minimal number of system components, and makes the most of the inherent high efficiency of the fuel cell. 

The performance of a SOFC system with a Brayton-Rankine bottoming cycle for heat and fuel recovery has been calculated. Gas turbine compressor and expander efficiencies of 83% and 89% and a steam turbine efficiency of 90% have been assumed. 

The results of the performance calculations for the fuel cell, Rankine cycle heat recovery system, summarized in Table 9-24, indicate that the efficiency of the overall system is increased from 57% for the fuel cell alone to 72% for the overall system. This Rankine cycle heat-fuel recovery arrangement is less complex but less efficient than the combined Brayton-Rankine cycle approach, and more complex and less efficient than the regenerative Brayton approach. It does, however, eliminate the requirement for a large, high temperature gas to gas heat exchanger. And in applications where cogeneration and the supply of heat is desired, it provides a source of steam. 

These three approaches to reject heat and exhaust fuel recovery with power generation apply primarily to the higher temperature, solid oxide (1800 F) and molten carbonate (1200 F), fuel cell systems operating on CH4 fuel. The lower operating temperatures of the phosphoric acid (400 F) and polymer electrolyte (175 F) fuel cells severely limit the effectiveness of thermal cycle based power generation as a practical means of heat recovery. 

Firedamp Recovery. Firedamp is essentially the same as natural gas and has value as a fuel. Recovery is practiced in Europe both for safety purposes (firedamp removed from the mine is no longer an expin hazard in the mine) and as a by-product for economic reasons. Recovery by several methods is possible. Some of these are cross-measure borehole methods from working galleries, boreholes from roads outside the seam being worked, superjacent heading method, suction, pack cavity method and blowers (Ref 3)... 

Fig. 21.19. General solvent extraction process for spent fuel recovery.

Highly enriched uranium containing >90% is, in general, only used in research reactors. The production of fissile nuclides is negligible, and the maximum burn-up is of the order of 10 MW d per ton of fuel, corresponding to the consumption of about 13% of the fuel. Recovery of the remaining is of economic interest. 

Total concentrations of silica and alumina in the fuel were 1.4 wt.% and O.S wt.% respectively (both values imply substantial soil contamination of the fuel, predominantly the wood fuel). Recoveries are good given the high silica and alumina concentrations of the bed media. Titanium, phosphorus and iron were mostly found in the coarse ash fraction and in the particle fraction of the stack flow. Alkaline-earth and alkali metals in the bed are primarily indicative of the fuel ash remaining in the bed. Substantial fractions of these elements were captured in the coarse ash fractions removed in the horizontal pass and by the cyclone, although about 10% is associated with the fine particle fraction passing the cyclone. Yields for all elements on the deposit probes are low due to the low deposit masses. 

A more radical modification of the Purex process, the Aquafluor process, developed by General Electric for its Midwest Fuel Recovery Plant, retained only a single TBP co-decontamina-tion cycle followed by a continuous anion exchange contactor in which plutonium was to be removed from the U-Pu nitrate solution. The performance of this plant was never tested with plutonium, since General Electric decided to forego operation of the plant after technical difficulties developed during the "cold" checkout trials. 

Exxon Nuclear Co., "PSAR Nuclear Fuel Recovery and Recycling Center," Vol. 4, US NRC, Docket-50564-7 1976. 

R. W. Lambert and J. M. Dotson, MFluidized-bed Applications in the Midwest Fuel Recovery Plant, Chemical Engineering Progress Symposium Series, Vol. 66 No. 105, 175-179. 

As our nuclear technology develops, the major sources of radioactive wastes will be reactor sites and fuel recovery sites. 

G4. General Electric Company Design and Analysis of Midwest Fuel Recovery Plant, Report Docket 50-268,1966. 

Less commercially attractive, but still potentially important, is injection into oil and gas fields that are either close to exhaustion (so-called depleted fields) or have been abandoned as unprofitable. Once the oil or gas has been extracted, there remains a large volume of porous rock in which carbon dioxide can be retained. In this situation, there is no credit for enhanced fuel recovery but, because the formation has safely held oil/gas for geological periods of time, there is again confidence that the carbon dioxide will remain locked up indefinitely. It is necessary, however, to ensure that any holes in the caprock due to drilling and oil extraction have been permanently sealed before introducing the gas. 

The NaBH4 hydrogen generation systems and devices are comparatively simple in their principles and components. They are basically composed of a catalytic reactor, fuel and fuel recovery tanks, mist and crystalline separators, condenser or heat exchanger, pump and pressure regulator. A hydrogen generation system for PEMFC is illustrated schematically in Fig. 6.45 and for an experimental set-up of 1 kW capacity in Fig. 6.46. 

Additional items in safety analysis, e.g. initiating events like collision, sinking, fuel recovery after sinking accident, extent of security ad safeguards implied in the design of plant and ports. 

Ore mining presents matty of the same dangers of harmful chemical modification ofthe environment as does fossil fuel recovery. Sulfur-containing minerals frequently ac-compaity ores and, unless properly recovered and treated, promote the formation of acid waters and contamination of the atmosphere with sulfur dioxide (SO2) and hydrogen sulfide (H2S). Acidic sludges and slurries are produced in conjunction with the recovery and processing of iron, copper, zinc, and lead cyanide salts are used in the recov-... 

Monsanto will recycle all types of carpeting which its customers replace with Monsanto nylon carpet. Nylon carpet face fiber, latex, and backing are recycled into thermoplastic pellets, which are reused industrially. The company is also exploring opportunities for reuse of carpet in fuel recovery systems, as well as for respinning postconsumer nylon carpet face fiber. 

The combination and integration of the above-described monitoring techniques was essential to provide an early warning system, which has been applied during both SaR activities and fuel recovery operations. In addition, the data collected and the interpretations were made available to the operators involved in the emergency scenario via daily bulletins, in order to support authorities and decision makers in their activity planning. 

The accidental criticality occurred Friday, July 24, 1964 in a process vessel at the Fuels Recovery Plant of United Nuclear Corporation s Fuels Division, located at Wood River Junction, Rhode Island. Uranium enriched to 93% in the U isotope, as a nitrate solution, was... 

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