HWCI - 1.0

Question 1

What are the automatic Shutdown conditions for HWCI?

Answer 1

• High Hydrogen Flow
• High Hydrogen Pressure
• Hi-Hi H2 Conc. in Area (50% of Lower Explosive Limit)
• Low Air Pressure
• Reactor Scram
• High Offgas Hydrogen Percentage
• Emergency Shutdown Pushbutton
• Offgas Train/Recombiner Trip

Question 2

What is required to cause Intergranular Stress Corrosion Cracking (IGSCC)?

Answer 2

• High [T]emperature
• [A]ustenitic Stainless Steel
• [C]hlorides
• [O]xygen
• Tensile [S]tress

[TACOS]

Question 3

How long can HWCI be removed from service?

Answer 3

8 hours

Question 4

What happens on a HWCI system trip?

Answer 4

All injection valves isolate and controller setpoint runs back to 0 (flow control valves will close).

Question 5

What is the Secondary Condensate Pump Interrelationship with the HWCI system?

Answer 5

• Can only place in service if associated SCP is in service and main hydrogen isolation valve (2101) is open
• An SCP trip isolates the associated train of HWCI.

Question 6

What does the Air Supply Station do?
What is its primary and backup sources?

Answer 6

• Provides a source of air into Gaseous Radwaste system recombiners.
  1) Supplied from the Station Service Air system.
  2) A back-up source of air is supplied from the Station Instrument Air system.

Question 7

Where does HWCI insert?

Answer 7

• Oxygen - PCP suction
• Hydrogen - SCP suction
• Air - Upstream preheater.

Question 8

What are the limitations of the MSLRM with reference to HWCI?

Answer 8

Prior to going below 20% rated thermal power, take HWCI OOS and lower MSL rad monitor setpoints to normal. No CR motion allowed until complete.