Refueling rate

It should also be noted from equation 9.1 that heat must be dissipated when refueling the tank (recharging the spent hydride), and for refueling rates equivalent to hlling conventional gas tanks, the cooling power could, for the more stable hydride materials, exceed the capacity of on-board coolant systems. In these cases, there would be an energy cost borne by the off-board refueling facility. 

Time period between refuelings (rated power) (year) 2... 

Approximately 25—30% of a reactor s fuel is removed and replaced during plaimed refueling outages, which normally occur every 12 to 18 months. Spent fuel is highly radioactive because it contains by-products from nuclear fission created during reactor operation. A characteristic of these radioactive materials is that they gradually decay, losing their radioactive properties at a set rate. Each radioactive component has a different rate of decay known as its half-life, which is the time it takes for a material to lose half of its radioactivity. The radioactive components in spent nuclear fuel include cobalt-60 (5-yr half-Hfe), cesium-137 (30-yr half-Hfe), and plutonium-239 (24,400-yr half-Hfe). 

The vapor vent valves are connected to the tank vapor control valve, and ultimately to the carbon canister by tubing that is resistant to swelling in the presence of fuel vapors. The tubing material must also have a low HC permeation rate, so that the evaporative emissions are not increased due to release of HC molecules. The tank vapor control valve connects the carbon canister to two fuel tank vapor sources the vapor vent valve lines and a refueling vent tube. 

The rate of vapor generation during refueling is a major parameter affecting the design of carbon canisters to meet ORVR requirements. 

R6, for eddy current testing of the steam generator tubes, is performed in a refueling ouiagL by quickly draining the RCS loops, hence, the decay heat rate is high. 

While refuelling dominates infrastructure investments in the early phases, in the later phases it is superseded by production. The total investment of the ten countries until 2025-2030 (i.e., to reach a hydrogen vehicle penetration rate of approximately 12%) is around 60 billion. Flowever, conventional fuels also require large investments e.g., the IEA recently assumed that a global investment of as much as US 4300 billion will be required in the oil sector until 2030, to maintain current production levels (IEA, 2006a). Even though a direct comparison of these numbers is not valid, this may be helpful for a placement of the investment needed for hydrogen infrastructure. 

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