by Greg Hollinger and George Antaki One of the qualification requirements for a piping system is to keep the loads imparted by the piping on equipment nozzles within certain allowable limits. These loads consist of sets of three forces and three moments, for the various load combinations. There are basically two types of nozzle load limits: […]
Becht Nuclear Services recently applied ANSYS® multi-surface, with fluid-structure interaction (FSI) capabilities to evaluate the effects of seismic loading on vessel internals that are immersed in the fluid. Before proceeding with the analysis of the actual vessel, the FSI capabilities were benchmarked to an analytical solution of a simpler liquid-filled flexible tank under seismic loading. […]
Design of a Nuclear Power Plant for a LOCA Nuclear power plants are designed with the capability to safely shut-down following a number of hypothetical accident scenarios. One of those accidents is the rupture of a pipe in the reactor coolant system (RCS). Such a rupture would result in a loss of coolant accident (LOCA), […]
Nuclear power plants are designed to be capable of a safe shut-down in case of a large design-basis tornado or hurricane. The magnitude of the postulated design-basis tornado or hurricane is such that there is less than 1 in 10 million chance (1E-7) per year and per reactor that it would be exceeded. This probability […]
It is normal for piping systems to exhibit steady pressure pulses. Most of the time these pulses are inconsequential; however, in a few cases they must be eliminated because they can affect the reliable operation of the system or they can cause a mechanical failure. Becht Engineering recently assisted a client in the evaluation of […]
Road Map of Regulatory Requirements General Design Criteria – The protection of nuclear power plants from the effects of tornadoes (or extreme winds from typhoons or hurricanes, depending on the locality) is required through 10CFR50 Appendix A, 10 CFR 50, Appendix A, General Design Criterion 2 which requires that structures, systems, and components (SSCs) important […]
Immediately following the Fukushima accident of March 11, 2011, the US Nuclear Regulatory Commission assembled a Near-Term Task Force to gather the lessons learned from the Fukushima Dai-Ichi accident. The Task Force compiled a set of “Recommendations for Enhancing Reactor Safety in the 21st Century.” The Recommendations were approved by the Commissioner and issued for […]
This article outlines the procedure to evaluate the fitness-for-service of corroded buried pipe, and explains what CC N-806 covers … and what it does not cover. What are the Damage Mechanisms in Metallic Buried Pipe? The inspection of a buried metallic pipe, after years of service, can reveal that the pipe has little if any […]
This article describes an integrated study of thermal-hydraulic and structural loading of bounding piping systems, to establish an operating envelope, screening criteria, and rules of good design practice to protect piping systems from damage caused by valve closure water hammer. Introduction In many cases of operation or flushing of piping system, it is necessary to […]
FAILURE MODE – When an explosion (either a subsonic deflagration, or a supersonic detonation) occurs in a metallic vessel, one of three things can happen: Case 1 – Containment: The vessel can contain the explosion, elastically as if nothing happened, or with plastic bulging. Case 2 – Rupture: The vessel can rupture, without ejecting fragments. […]
