DYNAMIC SAFETY ANALYSIS

The dynamic analysis has been performed for the seismic parameters, defined by geotechnical investigation as different types of earthquake with defined maximum expected input acceleration for the corresponding return period. Obtained as results from the dynamic analysis are the storey displacement and the ductility, required by the earthquake, that has to comply with the design seismic safety criteria (Sect. 8.3.4). The results from this analysis are given in Sects. 8.4.1, 8.4.2 and 8.4.3 for each of the analysed monument structures, respectively. 

The results show that the safety factor at first cracking and particularly at failure is greater than 1 for aU the storeys. Table 8.10 summarizes results for both structural units (storey stiffness K, ultimate capacity Q , factor of safety against failure F,j) that represent the input parameters for dynamic analysis. 

If the footing s safety factor for vertical loads is high, i.e., N N, there is very little hysteresis in cyclic loading and the cyclic M-0 relation is nonlinear-elastic, returning to about zero displacement at zero moment or force and dissipating very little energy. Then Eqs. (15.7) may be applied also in nonlinear dynamic analysis, with the twin springs taken as nonlinear elastic. 

Generic Safety Issue (GSI) 119.2 in NUREG-0933 (Reference 1), addresses the recommendations of the NRC Piping Review Committee (PRC) on how the NRC should modify their requirements for the damping values to be used in the dynamic analysis of nuclear power plant piping systems. 

The sensors should be located preferably at the free field and at the locations of safety related equipment in the plant. The trigger levels should be adapted to the locations of the sensors in the plant, in accordance with the seismic dynamic analysis. For multi-unit sites, the scram logic should be coordinated among the different units. 

Up to now we considered loads with respect to the ULS. However, the Eurocode [EN1995, EN1992, EN1990] stipulates that the dynamic analysis should be carried out in SLS. Therefore, we convert the loads in order to use them in a SLS-analysis. All quantities with respect to a SLS-analysis are marked with an. In ULS the partial safety coefficients are 1,35 and 1,5 for the permanent and live loads respectively, in SLS both are equal to 1. Therefore ... 

The first step of safety verification is to verify that the software requirements are consistent with or satisfy safety constraints. Safety verification exists to provide evidence that associated risk has been reduced or eliminated [1]. Safety verification is not the same as functional verification. Functional verification assures that the software fully satisfies its specifications, while safety verification uses the results of the safety analysis process to assure that the software meets the safety requirements [20]. The safety verification can be done in two ways [1] (1) static analysis which looks over the code and design documents of the system (e.g. fault tree, formal verification) and (2) dynamic analysis requires the execution of the software to check all of the systems safety features. Static analysis is the same as a structured code review. Systems can be proven to match requirements, but it will not catch any safety states that the requirements miss [Ij. The dynamic analysis has the ability to catch unanticipated safety problems, but it cannot prove that a system is safe (e.g. software testing). 

Vibratory loads induced by the impact should be evaluated by means of a specific dynamic analysis of structures and equipment, with account taken of the material properties of reinforced concrete subjected to dynamic loads (stiffness and damping). The floor response spectra should be calculated for all the main structural elements of the buildings which house safety related equipment. Appropriate transfer functions should be evaluated for the estimation of the vibratory action transferred to any safety related equipment. The numerical model should be specifically validated for the dynamic transient analysis, so as to guarantee a proper representation of the vibratory field at least in the frequency range in which the power spectrum of the load function has major contributions. 

Kloos, M. et al. 2013a. Advanced probabilistic dynamics analysis of fire fighting actions in a nuclear power plant with the MCDET tool. In Proceeding of European Safety and Reliability Conference ESREL 2013. Amsterdam, Netherlands. 

Shome N, Bazzurro P (2009) Comparison of vulnerability of a new high-rise concrete moment frame structure using HAZUS and nonlinear dynamic analysis. In 10th international conference on structural safety and reliability (ICOSSAR), Osaka... 

Adam C, Heuer R, Pirrotta A (2003) Experimental dynamic analysis of elastic-plastic shear frames with secondary structures. Exper Mech 43(2) 124—130 Bergman L, McFarland D, Hall J, Johnson E, Kareem A (1989) Optimal distribution of tuned mass dampers in wind-sensitive structures. In Structural safety and reliability, ASCE, pp 95-102 BisegnaP, Caruso G (2012) Closed-form formulas for the optimal pole-based design of tuned mass dampers. J Sound Vib 331(10) 2291-2314 Bobryk R, Chrzeszczyk A (2009) Stability regions for mathieu equation with imperfect periodicity. Phys Lett A 373(39) 3532-3535... 

NMR is an incredibly versatile tool that can be used for a wide array of applications, including determination of molecular structure, monitoring of molecular dynamics, chemical analysis, and imaging. NMR has found broad application in the food science and food processing areas (Belton et al., 1993, 1995, 1999 Colquhoun and Goodfellow, 1994 Eads, 1999 Gil et al., 1996 Hills, 1998 O Brien, 1992 Schmidt et al., 1996 Webb et al., 1995, 2001). The ability of NMR to quantify food properties and their spatiotemporal variation in a nondestructive, noninvasive manner is especially useful. In turn, these properties can then be related to the safety, stability, and quality of a food (Eads, 1999). Because food materials are transparent to the radio frequency electromagnetic radiation required in an NMR experiment, NMR can be used to probe virtually any type of food sample, from liquids, such as beverages, oils, and broth, to semisolids, such as cheese, mayonnaise, and bread, to solids, such as flour, powdered drink mixes, and potato chips. 

Because of concerns about the safety of radioisotope use, researchers are developing fluorescent and chemiluminescent methods for detection of small amounts of biomolecules on gels. One attractive approach is to label biomolecules before analysis with the coenzyme biotin. Biotin forms a strong complex with enzyme-linked streptavidin. Some dynamic property of the enzyme is then measured to locate the biotin-labeled biomolecule on the gel. These new methods approach the sensitivity of methods involving radiolabeled molecules, and rapid advances are being made. 

Steady-state modeling is not sufficient if one faces various disturbances in RA operations (e.g., feed variation) or tries to optimize the startup and shutdown phases of the process. In this case, a knowledge of dynamic process behavior is necessary. Further areas where the dynamic information is crucial are the process control as well as safety issues and training. Dynamic modeling can also be considered as the next step toward the deep process analysis that follows the steady-state modeling and is based on its results. 

The case study on Vinyl Acetate Process, developed in Chapter 10, demonstrates the benefit of solving a process design and plantwide control problem based on the analysis of the reactor/separation/recycles structure. In particular, it is demonstrated that the dynamic behavior of the chemical reactor and the recycle policy depend on the mechanism of the catalytic process, as well as on the safety constraints. Because low per pass conversion of both ethylene and acetic acid is needed, the temperature profile in the chemical reactor becomes the most important means for manipulating the reaction rate and hence ensuring the plant flexibility. The inventory of reactants is adapted accordingly by fresh reactant make-up directly in recycles. 

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