CNMT Purge Flashcards
1
Q
Purpose of CNMT purge system
A
- breathable atmosphere in cnmt for personnel entry in all modes
- reduce airborne radioactivity => exposure
- relieve excess pressure and vacuum
- means to pressurize cnmt for leak rate test
2
Q
Describe CNMT purge components
A
- supply fan (S-3), takes suction thru filter & htr
- supply CIV’s (FCV-661, 660), huge damper, air open, mech stop, valves leak=> don’t open modes 1-4
- exh CIV’s (RCV-11,12), damper, air open, mech stop, close on CVI signal
- exh fan (E-3), takes exhaust and disch to plant vent
- pressure/ vacuum relief line with 3 CIV’s, one inside CIV (FCV-662), one branch to supply(press relief, FCV-663), one branch to exh(vacuum relief FCV-664)
FCV’s close on CVI
3
Q
What are the signals that close CNMT purge supply fan CIV’s (FCV-660, 661)?
A
Si
Man phase A
Man phase B
RM-44A/B alarm
4
Q
Precautions and limitations for CNMT purge system
A
- do not purge w/o chem disch permit
- after op of CVI valves, leak test performed
- do not op FCV-660, 661, RCV-11,12 in modes 1-4 w/o ops manager position, fail leak test
5
Q
How is integrated leak rate test performed on cnmt?
A
Through connection in cnmt purge system via the press/ vacuum relief line (flange)
