Containment Hydrogen Control Flashcards
What is the main purpose for Containment Hydrogen Control ?
It’s used to monitor hydrogen concentrations in containment following a LOCA
Following a LOCA, how is hydrogen gas generated inside containment ?
-Metal water reaction involving zirconium fuel cladding & RC
-Radiolytic decomposition post-LOCA emergency cooling solutions
-Corrosion of metals & paints by solutions used for Emerg. Cooling or Containment Spray
What Hydrogen Monitoring subsystem is provided in units ?
-Hydrogen Gas Analyzers
-Containment Isolation Valves
What is the Hydrogen Monitoring system designed to do?
Designed to measure hydrogen concentration in Containment
What emergency operating procedures are used ?
-LOCA
-Excess Steam Demand
-Entry into functional Recovery Procedure
Where do the Hydrogen Analyzers draw from & discharge to ?
-Draw from containment atmosphere
-Discharges back to containment atmosphere
Where does the Hydrogen Analyzers suction pass through ?
-Passes through associated trains Inside Containment Isolation Valve
-Passes through Analyzer discharge through inside Containment Isolation Check Valve
How many hydrogen analyzers are there per train ?
There are two redundant Hydrogen Analyzers ONE per Train
What indications does each Hydrogen Analyzers ? Where do it show indication at ?
Provided indication for hydrogen concentration inside containment, locally at the analyzer & in Control Room
What’re the normal conditions for Hydrogen Analyzers ? How long can accurate readings be attained ?
-Normally in standby condition & placed in service by control room
-When placed in service readings can be attained in 30 minutes
How is Containment hydrogen concentration measured ?
Draws sample of containment atmosphere through each gas analyzer
What does each Gas Analyzer consist of ?
Consist of a:
-Sensor
-Electronic sub-assembly
-Local & remote alarms & readouts
What kind of Gas Bottles are used with Hydrogen Analyzer ?
-Span Gas & Reagent Gas mounted next to Hydrogen Analyzers
Why is Span Gas & Reagent Gas Bottles needed for the Hydrogen Analyzers ?
Span Gas Bottle- Required for calibration of Analyzer
Reagent Gas Bottle-Required for operation of Analyzer
When should the POST Accident Monitoring Instrumentation be FUNCTIONAL ?
In Modes 1,2,and 3 it shall be FUNCTIONAL
What does the Post-Accident Monitoring instrumentation ensure ?
-Ensures sufficient info is available on selected plant parameters to monitor & assess the variable following accident
What is the normal position of the Hydrogen Containment Isolation Valves ? What happens to containment isolations when Hydrogen Analyzers are placed in service ?
-They’re normally closed & will open when Hydrogen Analyzers are placed in service
Where are the Inside Containment Isolation Valves operated from ?
They’re operated from control room
What will auto close the Hydrogen Containment Isolation Valves ?
Automatically close on a CIAS
Hydrogen Control Monitoring subsystem is aligned for operation following what ?
-LOCA
-Excess Steam Demand
-Direction from Functional Recovery Procedure
How do Hydrogen Control Monitoring system interface with 480VAC CLASS(PH)?
PH provides power for:
-Hydrogen Analyzers
-Hydrogen Control Containment Isolation Valves
PH D-Panel provides 120VAC power to:
Hydrogen Analyzer Control Panels
How does Hydrogen Control Monitoring system interface with PK system ?
PK provides power to solenoid operated Hydrogen Analyzer Isolation Valves
How does Hydrogen Control system interface with Containment Building HVAC(HC) ?
HC provides mixing of Containment atmosphere which enables accurate reading by Hydrogen Analyzers
How does Containment Hydrogen Control interface with Heat Tracing(QM)?
-Heat Tracing provided to prevent condensation in supply line to Hydrogen Analyzers
How does Containment Hydrogen Control system interface with Safety Injection(SI)?
Containment Spray provides mixing of Containment Atmosphere to prevent localized buildup of hydrogen within Containment
How does Containment Hydrogen Control interface with ESFAS?
CIAS will close Containment Hydrogen Control Containment Isolation Valves
