大多数沸水反应堆（BWR）工厂的技术规格要求低压冷却液注入（LPCI）在模式1、2和3中都可以操作，并且如果在关闭冷却（SDC）操作时，LPCI仍然可以被视为可操作的津贴，如果它能够手动与LPCI模式对齐。人们担心RHR系统与圆环（或抑制池）的对齐，以减轻SDC操作期间冷却液事故（LOCA）的损失，会导致蒸汽空隙形成并在RHR泵的吸力和排放侧塌陷。
在短暂事件中，使用Relap5进行了一项针对Mark 1开水反应器（BWR）的低压冷却注射（LPCI）系统的蒸汽水锤现象的研究。特别感兴趣的情况是，由于冷却剂事故（LOCA）的损失，从关闭冷却模式3到低压注射的手动切换。通过打开LPCI系统上两个火车的隔离阀（MO-B1和MO-D1）进入圆环（见图1）来启动该瞬态。
在大气环被认为是总统sure and 68°F. The initial condition of the problem was set up such that the liquid was stagnant in the system. The initial temperature and pressure of the liquid, which was between the torus and isolation valves, was considered to be the same as the torus conditions. On the other hand, the initial condition of the liquid upstream of the isolation valves was chosen to be at 150 psia and near saturation temperature. The analysis showed that the liquid in the system flashed into steam and discharged into the torus after the isolation valves started to open. Discharge of steam continued until the pressure in the LPCI system reached to a hydrostatic equilibrium with the torus. Following this, the cold liquid from the torus began to reflood the LPCI piping while condensing the steam at the liquid-steam interphase. Figure 2 provides a pictorial presentation of the phenomena. These series of events caused a mild steam waterhammer event when all of the steam condensed in the piping segments with closed ends as shown in Figure 3. A sensitivity analysis showed that the magnitude of the steam waterhammer predicted by RELAP5 was sensitive to the number of nodes selected to model the piping, where the steam waterhammer phenomena occurred. Technical basis was obtained from the available literature and used as a guide to choose the number of nodes for the models in both codes. Once the steam waterhammer and the hydrodynamic properties associated with this transient were predicted by RELAP5, the forces exerted on critical pipe components were calculated using a one-dimensional momentum equation. Figure 4 shows the force, which was calculated on “B” Shutdown Cooling Line.
蒸汽水锤现象一直关注核工业。This is because of the fact that large waterhammer pressure and hydrodaynamic loads can potentially be generated that will challenge the integrity of various piping systems if a strong steam waterhammer occurs. As a result of this, the美国核监管委员会（USNRC）issued a generic letter,GL 96-06 (1996)。所有被许可人都必须对容易受到蒸汽水锤的各种系统进行评估。
单击此处以分析BWR LPCI系统中的冷凝诱导蒸汽水锤PDF
#WaterHammer，，，，#nuclearplant, #plant safety, #bwr, #piping systems, #nuclear plant, #nuclear industry
