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Development of PC-based Simulator for Korean APR 1400

By
Micro-Simulation Technology
USA
http://www.microsimtech.com

Video

Station Blackout Benchmark

In Vessel Retention Strategy (New)

PCTRAN/APR1400 NSSS mimic, Note 4 ECCS trains, IRWST, POSRV and SDV systems

APR1400 is Korean-designed next generation nuclear power plant (KSNP) up-scaled from OPR1000 to 1400 MW electric (4000 MW thermal).  The major upgrades related to simulator design are:

• Reduced hot leg temperature (324ºC) and increased pressurizer volume for larger thermal margin => enhanced transient response.
• Pilot Operated Safety Relief valves (POSRV) on the pressurizer; more stable operation.
• Four trains Safety Injection System with Direct Vessel Injection (DVI) => Eliminate cold leg spill.
• Fluidic device in SIS tank to regulate injection rate during LOCA.
• In-containment refueling water storage tank (IRWST) along with Safety Depressurization and Vent System (SDVS) actuation for a RCS depressurization. It performs water collection, supply and heat sink during normal and accident conditions, so eliminating sump recirculation following a LOCA.
• Hydrogen Management System (HMS).
• Passive Auto-catalytic Recombiners (PAR) limits the average H2 concentration.
• In-Vessel corium Retention through External Reactor Vessel Cooling (IVR-ERVC).
• Cavity Flooding System (CFS) to prevent vessel fail.
• Cooling and scrubbing the core debris.

They are incorporated into PCTRAN as seen in the NSSS and containment mimics.

The prototype is working and has been benchmarked against a few published studies by KAERI.  It includes a station blackout (SBO) up to 8 hours without core damage to meet the design criteria. All operational transient and accident cases are operable.

PCTRAN/APR1400 containment mimic - Note Cavity Flooding and debris scrubbing systems to direct water from IRWST into the cavity.

Direct Vessel Injection (DVI) Emergency Core Cooling System

Rather than injecting into the cold legs as traditional PWR’s, four trains of independent ECCS inject into the reactor vessel. In each Safety Injection Tank (SIT) there is fluidic device that increases the flow resistance when the driving head is reduced after initial refill phase following a large break loss-of-coolant-accident (LBLOCA). This saves coolant spill from the break and extends operation of SIT to the later reflood phase. Following is the ECCS flow requirement for conventional PWR and APR1400 according to KHNP:

A LBLOCA was conducted using PCTRAN/APR1400. 

The HPSI and SIT flows match both qualitatively and quantitatively well with the design.

Station Blackout Benchmark