Civil Engineering EPRI| 64 QUESTIONS| WITH COMPLETE SOLUTIONS

Why is civil engineering important in power plants? correct answer: Their main function is to maintain structural integrity of structures, systems, and components. Describe the design criteria and requirements for sites correct answer: - Soil structure interaction - Soil stability - Excavation Describe operating experience with external flooding, including causes, consequences, and preventive measures for sites correct answer: - Fukushima, Japan: An earthquake and subsequent tsunami at Fukushima nuclear plant in Japan in March, 2011 caused flooding that led to loss of all but one of the emergency diesel generators on this six unit site. ALL units lost off-site power and the on-site electrical distribution equipment. Engineers had earlier determined thatFukushima could be exposed to a tsunami larger than the design basis tsunami, but protection features were not installed for a larger tsunami. Without power for the core cooling equipment, the core overheated and the fuel cladding burned. Hydrogen gas vented from the reactor exploded in the containment building, releasing fission products from the fuel to the environment. - Ft. Calhoun, Nebraska: Record level flooding of the Missouri River caused by excessive rain threatened the Ft. Calhoun Nuclear Plant in Nebraska in June, 2011, but there was no damage to the nuclear facility. In addition to the existing protective features, such as watertight buildings and auxiliary electrical power sources, station personnel implemented additional, temporary actions to protect the facility. The additional actions included installation of a water barrier around the facility, installation of overhead electric power lines to the plant, and the addition of another electric diesel generator to support the existing emergency generators. The lessons learned from Fukushima proved advantageous for the staff at Ft. Calhoun. What is soil-structure interaction? correct answer: It is the dynamic response of a structure coupled to its supporting medium. What characteristics do soil-interaction response rely on? correct answer: - The earthquake ground motion - The surrounding soil profile - The structure itself What does it mean when there is little or no soil-structure interaction? correct answer: When there is little or no soil-structure interaction, motion at the base of the structure is essentially the same as ground motion recorded at a distance away from the structure. What are the characteristics of structures that allow for low levels of soil-structure interaction? correct answer: - Light, surface-founded structure - Founded on rock or stiff soil