Mock-ups

If possible, this can be done by building a 1 1 mock-up of the measuring position, using the same pipe dimensions and material as in the process part. The mock-up should then be filled with a suitable liquid, in this case gasoline or light petroleum, to which a precisely measured amount of tracer is added. This way, the response towards a known dilution of the tracer can be found. 

The problem of correcting for inevitable, small differences between the mock-up and the process persists ... 

The density and elementary composition of the liquid used in the mock-up may not match that of the process stream. 

The solution adopted by us is the use of computer simulations of mathematical models of the process and the mock-up situations. Eventually, simulation techniques will become so accurate, that the mock-up step can be discarded. For the time being it is reasonable to use such models to generate corrections for smaller differences between mock-up and process. 

A critical assembly is a split bed on which fissionable material used to mock up up a separated reactor core that is stacked half on each half. One half is on roller guides so that the two halves may be quickly pulled apart if the neutron multiplication gets too high. Use the Preliminary Hazards Analysis method described in section 3,2.1 to identify the possible accidents that may occur and the qualitative probabilities and consequences. List the initiators in a matrix to systematically investigate the whole process. Don t forget human error. 

The withheld information technique is used to explore the manner in which operators select and use information in process abnormalities. A particular abnormal process event is represented in a control panel "mock-up" or a "low-fidelity" simulator, and information is withheld from the worker until it is requested. This technique has been developed by Marshall et al. (1981) and has been used to elicit the diagnostic plans used by experienced workers during various process transients in a crude distillation imit. There are three main applications of this technique ... 

In an ideal situation the parameters used to define furniture should be ignition resistance and the rate of generation of heat, smoke and toxic gases. Tests to do this with actual or mock-up full sized furniture are not yet available as final specifications but the Nordtest (28) and NBS furniture calorimeters (29) represent scientific methods while room/ corridor rigs, typically UK DOE PSA FR5 and 6 of 1976 (5) (6) were originally used but are less satisfactory from a scientific point of view. The Californian (30) and Boston tests (31) for public area furniture are essentially simple room tests and are similar in principle to DOE, PSA, FR5 and 6 although the latter do not have pass/fail criteria. Bench scale rate of heat release tests include the NBS cone (29) which, with a code of practice represent a possible alternative but the rate of burning of... 

Standard Methods of Tests for Determing Resistance of Mock-Up Upholstered Furniture Material Assemblies to Ignition by Smoldering Cigarettes, 1989. 

For example, the GUI of a typical development might be documented only with storyboards and GUI mock-ups that are annotated with explanatory notes, with an optional mapping to the type model. Other design discussions, and specification of business behavior, use proper action specifications. Exceptions may be done more or less formally, depending on project needs. 

Typical cycles in software development might include feasibility study, GUI mock-up, requirements analysis and prototype, single-user, single-machine vertical incremental slices, tightening of relations between documentation layers, distribution across hosts, and multiuser deployment. A typical 10-person software development might use cycles ranging from two to six weeks. 

Haakana et al. (2004) used various mock-up experiments to achieve deep understanding of the different simultaneous phenomena in monolith reactors. However, they pointed out that the results obtained from mock-up experiments might not properly represent tlie overall reactor performance. This is an inherent limitation of mock-up experiments, where each phenomenon is studied in the absence of the others. However, during the real operation... 

Figure 8 Concept of H2S04 decomposer and mock-up model...

JAEA conducted an improvement of the RELAP5 MOD3 code (US NRC, 1995), the system analysis code originally developed for LWR systems, to extend its applicability to VHTR systems (Takamatsu, 2004). Also, a chemistry model for the IS process was incorporated into the code to evaluate the dynamic characteristics of process heat exchangers in the IS process (Sato, 2007). The code covers reactor power behaviour, thermal-hydraulics of helium gases, thermal-hydraulics of the two-phase steam-water mixture, chemical reactions in the process heat exchangers and control system characteristics. Field equations consist of mass continuity, momentum conservation and energy conservation with a two-fluid model and reactor power is calculated by point reactor kinetics equations. The code was validated by the experimental data obtained by the HTTR operations and mock-up test facility (Takamatsu, 2004 Ohashi, 2006). 

Ohashi, H., et al. (2006), Development of Control Technology for HTTR Hydrogen Production System with Mock-up Test Facility System Controllability Test for Loss of Chemical Reaction , Nuclear... 

---