POWER RANGE NUCLEAR INSTRUMENTATION

SUMMARIZE the operation of typical source, intermediate, and power range nuclear instruments. 

In this chapter we consider the nucleus and nuclear properties. The behavior of nuclei may have as great an effect on our everyday lives as any of the thousands of S)mthetic compounds developed over the past several decades. Examples of nuclear technology range from everyday items (smoke detectors) to sophisticated instruments for medical diagnosis and treatment and electrical power generation (nuclear power plants). 

The nuclear instrumentation must be operable prior to reactor startup. The automatic rod control during startup will not operate if more than one of the three ex-vessel wide-range channels is out of service. The Safety Protection Subsystem requires at least three of its four nuclear input channels operating. The power range neutron flux control will not operate automatically with more than two of the six input channels out of service. 

Recovery of metals such as copper, the operation of batteries (cells) in portable electronic equipment, the reprocessing of fission products in the nuclear power industry and a very wide range of gas-phase processes catalysed by condensed phase materials are applied chemical processes, other than PTC, in which chemical reactions are coupled to mass transport within phases, or across phase boundaries. Their mechanistic investigation requires special techniques, instrumentation and skills covered here in Chapter 5, but not usually encountered in undergraduate chemistry degrees. Electrochemistry generally involves reactions at phase boundaries, so there are connections here between Chapter 5 (Reaction kinetics in multiphase systems) and Chapter 6 (Electrochemical methods of investigating reaction mechanisms). 

Figure 3.22 The power distribution for a 10 ps rectangular pulse of 500 MHz RF radiation, (a) Distribution over a 400 kHz range, (b) The power level drops to 97% of the maximum at 5 kHz (10 ppm) on both sides of the center of the spectrum. This can affect the accuracy of integrals for resonances in different regions of the spectrum. (From Petersheim, M., Nuclear magnetic resonance, in Ewing, G.A., ed.. Analytical Instrumentation Handbook, 2nd edn., Marcel Dekker, Inc., New York, 1997. Used with permission.)...

The nuclear flux level and rate of change of flux is monitored in the sub-critical range, in the intermediate power level range, and in the operating range by multiple sensing and control systems, each consisting of multiple fail-safe components. Any one of these systems, except for the subcritical instruments, will automatically shut down the reactor complex in the event that process limits are exceeded. 

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