High Pressure Coolant Injection (HPCI) System

The HPCI is used in BWR-2 through BWR-4 boiling water reactor designs. The HPCI system is a single-train system that provides a reliable source of high-pressure coolant for cases where there is a loss of normal core coolant inventory. The HPCI system consists of a steam turbine-driven pump, valves and valve operators, and associated piping, including that from the normal and alternate pump suction sources and the pump discharge up to the penetration of the main feedwater line. For this study, the part of the main feedwater line from the check valve upstream of the HPCI connection to the reactor vessel, including the check valve, was considered part of the HPCI system. The steam turbine-driven pump includes all steam piping from the main steam line penetration to the turbine, and turbine exhaust piping to the suppression pool, valves and valve operators, gland sealing steam, and the turbine auxiliary oil system.

The HPCI system is actuated by either a low reactor water level or a high drywell pressure. Initially the system operates in an open loop mode, taking suction from the condensate storage tank (CST) and injecting water into the reactor pressure vessel (RPV) via one of the main feedwater lines. When the level in the CST reaches a low-level setpoint, the HPCI pump suction is aligned to the suppression pool. To maintain RPV level after the initial recovery, the HPCI system is placed in manual control, which may involve controlling turbine speed, diverting flow through minimum-flow or test lines, cycling the injection motor-operated valve (MOV), or complete stop-start cycles. The HPCI system is also manually used to help control RPV pressure following a transient.

The initial system study is documented in "High-Pressure Coolant Injection (HPCI) System Performance, 1987-1993 Final" (NUREG/CR-5500, Volume 4 ). The links below provide the current information for the study and latest results.

Current Results (SPAR-based):

• HPCI 2022 Summary Update

Historical Results (SPAR-based):

• HPCI 2020 Summary Update
• HPCI 2018 Summary Update
• HPCI 2016 Summary Update
• HPCI 2014 Summary Update
• HPCI 2013 Summary Update
• HPCI 2012 Summary Update
• HPCI 2011 Summary Update
• HPCI 2010 Summary Update
• HPCI 2009 Summary Update
• HPCI 2008 Summary Update
• HPCI 2007 Summary Update
• HPCI 2006 Summary Update

Historical Results (LER-based):

• HPCI 2005 Summary Update
• HPCI 2004 Summary Update
• HPCI 2003 Summary Update
• HPCI 2002 Summary Update
• HPCI 1998 Executive Summary (from original NUREG)
• "High-Pressure Coolant Injection (HPCI) System Performance, 1987-1993"
  (NUREG/CR-5500, Volume 4 )

Supporting Information:

• HPCI System Description
• HPCI System Fault Tree