Margin requirements, monitoring

Independent monitoring of market movements and margin requirements. 

Sensitivity and Resolution. The detection sensitivity and resolution of a gas detector must match the monitoring requirements for the target gas and provide an acceptable margin of safety in the event of atoxic gas leak. If a gas with a TLV of 50 parts per billion (PPB) requires monitoring and the established alarm setpoint is one half the TLV (i.e., 25 PPB), a gas detector with sensitivity and resolution in parts per million would be totally inadequate for the application. 

Process control plays an important role in how a plant process upset can be controlled and subsequent emergency actions executed. Without adequate and reliable process controls, an unexpected process occurrence cannot be monitored, controlled and eliminated. Process controls can range from simple manual actions to computer logic controllers, remote from the required action point, with supplemental instrumentation feedback systems. These systems should be designed such as to minimize the need to activate secondary safety devices. The process principles, margins allowed, reliability and the means of process control are mechanisms of inherent safety that will influence the risk level at a facility. 

Also the mode of adsorption (e.g. of CO, hydrocarbons, etc.) can depend on the available ensemble size or given composition of the surface [64—68]. It appears that the heat of adsorption of various modes of CO adsorption is only marginally influenced when the required ensemble (1,2 or 3 and more) is transferred from a pure metal into a matrix of another metal (for instance alloys with Cu, Au and Ag). When a CO molecule, monitored by IR spectroscopy, is taken as a probe of the local electronic structure of atoms (or ensembles of atoms), no pronounced effects of alloying are found 69-71]. 

Medications that have a low TI are said to have a narrow margin of safety and require that drug levels in the plasma be monitored and if necessary adjustments to the dosage be made to prevent a toxic effect from occurring. 

The safety of a dmg is identified by the dmg s therapeutic index. A low therapeutic index means a dmg has a narrow margin of safety requiring that that the dmg s peak level and trough levels be closely monitored. A high therapeutic index means a dmg has a broad margin of safety and does not require frequent monitoring of the patient and the semm dmg level. 

In the shutdown mode, the reactor vessel is fully pressurized or, at different times, in various stages of depressurization. Afterheat from fission product decay is generated at rates of up to about 7 percent of the core power level prior to shutdown, depending on the time interval since shutdown. The core decay heat is removed by the HTS. When the HTS is not available, the heat is removed by the Shutdown Cooling System (SCS). The outer control rods are normally fully Inserted during shutdown, and meet the required shutdown margin, with due allowances for uncertainties, even if the maximvim reactivity worth rod remains fully withdrawn. For cold shutdown, the control rods in the inner reflector are also Inserted and for this case, the maximum reactivity worth control rod is in the inner reflector. The neutron flux level is continuously monitored by the source range detectors. 

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