What is chemical and volume control system?

The Chemical and Volume Control System (CVCS) is an auxiliary support system that serves to: clean a portion of the Reactor Coolant System (RCS), maintain the correct concentration of Boron as a chemical shim, and adjusts the volume of RCS inventory as needed to maintain the operating level in the pressurizer.

What component in the CVCS system ensures NPSH is maintained for the charging pumps?

The vent line contains a remotely operated solenoid valve and a pressure regulating valve. The pressure regulating valve senses VCT pressure and closes if pressure drops to 15 psig, to ensure an adequate net positive suction head (NPSH) for the charging pumps.

What is the purpose of coolant in a nuclear reactor?

A substance circulated through a nuclear reactor to remove or transfer heat. The most commonly used coolant in the United States is water.

What happens to the heat removed from the reactor coolant by the letdown heat exchanger?

The heat from the reactor coolant is transferred to the component cooling water which is circulating through the shell side of the RHR heat exchangers.

What is Npsha in pump?

Net Positive Suction Head Available is calculated from the suction-side system configuration. It is essentially the suction-side pressure less the vapour pressure of the pumped fluid at that point. NPSH-A must exceed the pump’s NPSH-R rating for the chosen operating conditions to ensure that cavitation is avoided.

What is the function of the primary coolant in a nuclear reactor quizlet?

What is the function of the primary coolant in a nuclear reactor? The primary coolant absorbs the heat generated in the nuclear reactor and transfers it to the steam generator.

What happens when NPSHa is equal to NPSHr?

Based on the last few paragraphs what you may be realizing for the first time is that operating a pump with NPSHa equal to the pump’s NPSHr will mean that the TDH produced by the pump will be reduced by 3\%. By requiring a minimum margin between system NPSHa and pump NPSHr.

What is difference between NPSHA and NPSHR?

NPSHA is a function of your system and must be calculated, whereas NPSHR is a function of the pump and must be provided by the pump manufacturer. NPSHA MUST be greater than NPSHR for the pump system to operate without cavitating.

What is Thoma’s cavitation factor?

Thoma’s Cavitation Factor: It is an equation which is used to measure the cavitation in a hydraulic pump installation. It is denoted by the symbol ‘σ’. NPSHA (Net positive suction head available) is the difference between the absolute head at the inlet of the pump and the vapour pressure head.