Fuel verification methods

The physical and mathematical model of the determination of ignition rate are not explicitly formulated. However, it is understood from the displayed graphs that the ten thermocouples inserted in the fuel bed are used to detect the speed of the ignition front. The thermocouples are placed with a known distance between them. Furthermore, Rogers states The ignition rates were computed as the product of the rate of travel of the ignition front and the initial bed density . No verification method was used. 

Although the technique is more expensive than radiometry, mass spectrometry is, however, the preferred method for IDA of samples of nuclear materials taken for accountability verifications. Traditionally, separated or highly enriched isotopes, absent from the samples or only present as minor isotopes, such as Pu, Pu or Th were used as spike material in isotope dilution mass spectrometry. IDMS is the standard operator method for the accountability of nuclear materials in input solutions of irradiated nuclear fuels. The method involves taking a representative sample from the input accountability tank and diluting it accurately 100-1,000-fold in a heavily shielded cell. A portion of the diluted solution is transferred to... 

Verification Methods in Fuel Cell Process Engineering... 

In this section, selected verification methods are highhghted that can be used effectively in the development of fuel cell systems. Fuel cells are characterized by their high efficiency and low emissions. However, different applications have different requirements on fuel ceU systems. For example, the system may have to be designed for maximum lifetime, minimum weight and volume, and maximum efficiency, or for additional benefits, such as water production or tank inerting as... 

In this section, selected analysis methods will be highhghted that can be used efficiently in the development of fuel cell systems. The first method deals with systems analysis via statistical methods. In the previous section, the DOE approach was discussed as a verification method in fuel cell process engineering. This methodology is useful not just for designing effective experiments, but also for designing detailed process and systems analyses, which are often used for the development of fuel cell systems. 

Methods of achieving a conservative safety margin for prototypical fuels Verification of fuel integrity and... 

Experimental methods presented in the literature may prove of value in combustion studies of both solid and liquid suspensions. Such suspensions include the common liquid spray. Uniform droplets can be produced by aerosol generators, spinning disks, vibrating capillary tubes, and other techniques. Mechanical, physicochemical, optical, and electrical means are available for determination of droplet size and distribution. The size distribution, aggregation, and electrical properties of suspended particles are discussed as well as their flow and metering characteristics. The study of continuous fuel sprays includes both analytical and experimental procedures. Rayleigh s work on liquid jet breakup is reviewed and its subsequent verification and limitations are shown. 

Xu et al. (2006b) have successfully introduced Brinkman-Forchheimer-extended Darcy equation in order to solve the performance of molten carbonate fuel cell. As a verification of REV method, Poiseuille flow profiles in the porous media modifying LBM with... 

Heat transfer in square bundles is roughly estimated, so special experiments are needed for verification. By now there are no convincing methods of extrapolation of the data on temperature non-uniformity in the area around fuel pin to the square grid bundle. As a first approximation, it can be assumed that values increase in the same way as in case of laminar flow. Unfortunately, this cannot be adopted for the peripheral pins where temperature pattern non-uniformity is significant. Therefore, additional experimental studies are needed. 

A core management code system has been developed to predict the core parameters for operation and refueling plans within the design limitations. The nuclear calculation is based on diffusion theory and corrected with a bias method. Results from core physics tests and Post Irradiation Examinations (PIE) have been used to confirm the accuracy of these predictions. These verifications are also important to conduct various irradiation tests accurately. This section describes the method and verification for core and fuel management used with the JOYO MK-II core. 

The experience base for GCR fuel behaviour under accident conditions was reviewed at an IAEA Specialists Meeting in 1990 [Ref. 2], and a CRP on Validation of Predictive Methods for Fuel and Fission Product Behaviour in GCRs was initiated in 1993. Countries participating in this CRP include China, France, Japan, Poland, Germany, the USA and the Russian Federation. Within this CRP, participants are documenting the status of the experimental data base and predictive methods, cooperating in methods verification and validation and will identify and document the additional needs for methods development and experimental validation data. 

The hybrid K-edge densitometer (HKED) turned out to find quicker applications for safeguards verifications (Ottmar et al. 1986 Ottmar and Eberle 1991) at the input of spent fuel reprocessing plants, as the sample needs neither a dilution nor any treatment before measurement. The technique, considered as an NDA method and described in Sect. 63.3.1, is installed in particular in on-site analytical laboratories and operated by analytical chemists on duty there. Operators have found the instrument so practical and reliable that they use it in their nuclear material accountability program (Brousse et al. 1993). The HKED fluorescence channel is also used for DA of Th or mg-size Pu samples. 

MCFCs based on natural gas fuel have been commerciaUzed across the world. In general, natural gas MCFCs are economically inferior to coal power electricity. More economic fuels such as decomposition gas of organic waste and coal gas, and so on, are required for wide scale use of MCFC. To investigate the validity of a new fuel, performance analysis tools should be prepared. The methods in this work can be utilized, but some improvements are also necessary. One is the establishment of a theoretical and experimental basis of the AC impedance method for the performance analysis of MCFCs. The strong point of convenient measurement of the method has been weakened by its obscure analytical basis. Another one is the verification of the relationships among the measurement tools listed in this work. 

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