Low Power Tests

Every control rod s worth was calibrated with either the positive period method or the inverse kinetics method during the low power test of each operational cycle. The calculation was conducted with the CITATION code based on three dimensional diffusion theory using the same cross section, geometry and atomic number densities as MAGI. After correcting with the previous cycle s C/E, the calculated values were compared with the measurements. 

Low Power Test 50MW Performance Test 50MW Opera- tion 75 MW Performance Test 75MW Operation MK-il Performance Test lOOMW Operation... 

After the operating characteristics of the reactor have been verified by low-power testing, a power ascension programme brings the unit to its full rated power level in successive stages. At each successive stage, hold points are provided to evaluate and approve test results prior to proceeding... 

Following successful completion of the initial criticality tests, low power tests are conducted, typically at power levels less than 5 %, to measure physics characteristics of the reactor system and to verify the operability of the plant systems at low power levels. These tests are described in detail in Section 14.2. 10.3 of the EDCD (Reference 10.3 and identified below ... 

Stage B fuel loading tests, initial criticality tests and low power tests ... 

The second important component is the cooling agent or reactor coolant which extracts the heat of fission for some usefiil purpose and prevents melting of the reactor materials. The most common coolant is ordinary water at high temperature and high pressure to limit the extent of boiling. Other coolants that have been used are Hquid sodium, sodium—potassium alloy, helium, air, and carbon dioxide (qv). Surface cooling by air is limited to unreflected test reactors or experimental reactors operated at very low power. 

Occasionally, corrosion of this type produces large cavities covered by a thin outer skin of weld metal (Fig. 15.5). Even close examinations of such sites under a low-power microscope may fail to reveal the cavities. Compare Figs. 15.6 and 15.7. Generally, such sites are detected either by fluid leakage or by nondestructive testing techniques such as radiography and ultrasonics. 

Vibratory test apparatuses are relatively cheap to build and run, and have low power consumption, while flow rigs are bulky, expensive to build and run, and have high power consumptions but have the advantage that they simulate more closely practical conditions of hydrodynamic cavitation. On the other hand, the damage rate is higher in the vibratory tests than in the... 

Equally severe in practice is the requirement of the break 2 test. To pass this test the explosive must have a low power when fired in an unconfined condition. The actual power has not been quantitatively measured, but is probably in the region of 15% blasting gelatine. To achieve such a result, it is necessary deliberately to design the explosive in such a way that only partial reaction occurs in the unstemmed condition. Such partial reaction can be achieved by either of two ways. 

PEFC The PEFC, like the SOFC, has a solid electrolyte. As a result, this cell exhibits excellent resistance to gas crossover. In contrast to the SOFC, the cell operates at a low 80°C. This results in a capability to bring the cell to its operating temperature quickly, but the rejected heat cannot be used for cogeneration or additional power. Test results have shown that the cell can operate at very high current densities compared to the other cells. However, heat and water management issues may limit the operating power density of a practical system. The PEFC tolerance for CO is in the low ppm level. 

Dependencies may be detected using statistical tests and graphical analysis. Scatter plots may be particularly helpful. Some software for statistical graphics will plot scatter plots for all pairs of variables in a data set in the form of a scatter-plot matrix. For tests of independence, nonparametric tests such as Kendall s x are available, as well as tests based on the normal distribution. However, with limited data, there will be low power for tests of independence, so an assumption of independence should be scientifically plausible. 

Statistical tests will have relatively low power. In particular, there will be low power for testing the fit of a parametric distribution. 

Certain methods associated with normality, such as the t interval for the mean, are equally valid at aU sample sizes, so long as normality and other assumptions are accurate, and in most situations will improve in performance with increasing n. With small n one has low power for testing distributional assumptions. 

When using such a statistical significance test, it is important to recognise that this generally has low power in a trial designed to detect the main effect of treatment/... 

Iron-air cells have been developed by Matsushita Battery Industrial Co. and by the Swedish National Development Co., which have given an energy density of 80 Wh/kg at C/5 and a cycle life of 200 cycles to 60% depth of discharge. The latter company have produced 15-30 kWh batteries for EV testing. One limitation of the iron-air system for this application is the low power density achieved - a maximum value of 30-40 W/kg is reported. Similar cells are also being developed by Westinghouse (USA) and Siemens (Germany). 

The acid test of a crystal s suitability for structure determination is, of course, its capacity to give sharp diffraction patterns with clear reflections at large angles from the X-ray beam. A brief inspection of crystals under a low-power light microscope can also provide some insight into quality and can help the crystallographer pick out the most promising crystals. 

The SL-1 (Stationary Low Power No. 1) was a 3-MW (thermal) boiling water reactor operated by military personnel at the National Reactor Testing Station, Idaho. As a result of interference with the control rods, there was an explosion on 3 January 1961 in which about 5 tonne of coolant were expelled from the pressure vessel (Horan Gammil, 1963). 

The study of pyridine-piperidine reactions under high pressure conditions has given much information concerning the kinetics of HDN, but these results are however complicated by alkyl transfer (disproportionation) reactions, and thus the possibility of using such reactions as an easy test for determination of mechanism and as a catalyst probe is partly excluded. The study of polycyclic amines (quinoline, etc.) for the same purpose is limited by the complexity and the number of different possible routes, but is a very interesting test reaction for an overall study of catalytic activity or selectivity toward HDN in industrial conditions. Because no disproportionation occurs and the numbers of products and routes are reasonable, the studies of pyridine-piperidine and alkylpyridine-alkylpiperidine HDN under normal H2 pressure and low amine pressure (< lOTorr) are very powerful test reactions both for mechanism determination and catalyst study, although these conditions are far removed from those of industrial practice. 

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