EO 1 BLOCK 4 Nitrogen Flashcards
Which ONE of the following statements is NOT correct concerning the purposes of the Nitrogen
System?
A. Low Pressure Nitrogen is used as a blanketing gas for corrosion control in various radwaste
system components.
B. Low Pressure Nitrogen is used as a freeze seal gas for the Reactor Coolant System Hot Leg
piping bends.
C. Low Pressure Nitrogen is used for initial pressurization of core flood tanks (to ~ 100 psig), then
High Pressure Nitrogen is used for pressurization to 600 psig.
D. The Emergency Nitrogen System can be used to back up both the High Pressure and Low
Pressure Nitrogen headers, once valved in.
B
Which ONE of the following statements is correct concerning the Nitrogen System?
A. The Containment Electrical Penetrations are maintained leakage free by nitrogen from the
Low Pressure Nitrogen header.
B. The Cryogenic storage tank is actually an evacuated, insulated container designed to maintain
liquid Nitrogen at approximately - 275°F.
C. The atmospheric vaporizers transfer heat from the liquid Nitrogen to the surrounding
atmosphere, liquefying 110 CFH of Nitrogen at 1000 psig.
D. Each Main Steam Isolation Valve is supplied with Nitrogen for normal valve operation via a
pressure control valve off the Low Pressure Nitrogen header.
B
Which ONE of the following statements correctly describes control functions within the Nitrogen
System?
4
A. NN 236, Nitrogen System Containment Isolation valve, will automatically close when
Containment radiation exceeds two times background levels.
B. With NO flow in the Low Pressure Nitrogen Header, the electric strip heaters are deenergized.
C. In the Nitrogen System heater control circuits, a HIGH temperature condition will AUTO
RESET, and a HIGH-HIGH temperature condition must be MANUALLY RESET.
D. Low Pressure header pressure control valve, PCV 808, is set to maintain the header at 200
psig ± 20 psig for normal system operation.
C
Which ONE of the following Safety Features Actuation System Actuation levels will close the
Nitrogen to Containment Isolation Valve NN236?
A. Level 1
B. Level 2
C. Level 3
D. Level 4
B
From the following combinations select the SETPOINTS for annunciator 9-5-F, N2 HDR PRESS.
A. 120, 80 psig
B. 140, 65 psig
C. 100, 55 psig
D. 180, 90 psig
A
Choose the pressure that will cause annunciator 9-5-F, N2 HOR PRESS to alarm.
A. 80 psig
B. 85 psig
C. 90 psig
D. 100 psig
A
Which ONE of the following statements represents appropriate safety precautions for the handling
and use of liquid Nitrogen?
A. Nitrogen is highly reactive and requires a very closely monitored oxygen-free atmosphere to
preclude explosion.
B. When Nitrogen is released, it rapidly expands such that the atmosphere, if not well ventilated,
can become non-life supporting.
C. Waste liquid Nitrogen should be spread out over a concrete floor or driveway to allow it to
evaporate.
D. Since liquid Nitrogen is colorless, odorless, and inert, no skin protection is required to be worn
during its handling.
B
Which ONE of the following statements describes a limit and precaution as listed in DB-OP-06252,
Nitrogen Supply System?
A. Never close two (2) valves in series WITH a relief valve in between, because the expansion of
the Nitrogen upon heating will result in a lifting of the valve.
B. Nitrogen injected into the Reactor Coolant piping at the top of the hot legs must not reduce
nozzle temperature by more than a total of 200°F.
C. The temperature of the Nitrogen injected into the Core Flood Tanks must not be less than
40°F.
D. Don’t allow Cryogenic Nitrogen storage tank level to fall below 24 inches water gauge to
ensure that the tank does not lose positive pressure and warm up.
C
