What component provides initial borated water and helps maintain coolant inventory during a small LOCA?

What component provides initial borated water and helps maintain coolant inventory during a small LOCA?

• A. HPSI pumps, accumulators, LPSI pumps, and injection lines
• B. Turbine, condenser, feedwater
• C. Control rods and diesel generators
• D. Ventilation system

Answer: (A)

During a small LOCA, the emergency make-up of borated water and preservation of coolant inventory is handled by the safety injection systems and their delivery piping. The high-pressure safety injection (HPSI) pumps push borated water into the reactor coolant system to quickly restore pressure and inventory. If pressure falls, the accumulators automatically inject borated water, providing an immediate initial injection. As the system pressure decreases further, low-pressure safety injection (LPSI) pumps continue to supply borated water to maintain the coolant level and keep the reactor subcritical by adding neutron poison. The injection lines are the piping that delivers this borated water into the reactor coolant system. The other components listed don’t provide this function: the turbine, condenser, and feedwater belong to the secondary side of the plant and don’t deliver borated water; control rods and diesel generators relate to reactivity control and power backup but not the borated-water injection; the ventilation system isn’t involved in supplying coolant or neutron poison during a LOCA.

During a small LOCA, the emergency make-up of borated water and preservation of coolant inventory is handled by the safety injection systems and their delivery piping. The high-pressure safety injection (HPSI) pumps push borated water into the reactor coolant system to quickly restore pressure and inventory. If pressure falls, the accumulators automatically inject borated water, providing an immediate initial injection. As the system pressure decreases further, low-pressure safety injection (LPSI) pumps continue to supply borated water to maintain the coolant level and keep the reactor subcritical by adding neutron poison. The injection lines are the piping that delivers this borated water into the reactor coolant system.

The other components listed don’t provide this function: the turbine, condenser, and feedwater belong to the secondary side of the plant and don’t deliver borated water; control rods and diesel generators relate to reactivity control and power backup but not the borated-water injection; the ventilation system isn’t involved in supplying coolant or neutron poison during a LOCA.