NC (Nuclear Cooling Water) Flashcards
The plant is operating at 100% power The nuclear cooling water system has been lost All other systems are/were operating normally Which one of the following describes how much time is available to either restore cooling flow to the reactor coolant pumps or stop the pumps and isolate seal bleed-off?
A. 10 minutes.
B. 3 minutes.
C. 5 minutes.
D. 13 minutes.
Answer: A
Unit 1 is in Mode 1 ‘A’ NCW Pump is under Permit ‘B’ NCW pump trips and is locked out The Operating Crew directed to restore Nuclear Cooling Water flow within …..
A. 3 minutes or commence a controlled shutdown.
B. 10 minutes or trip the reactor, stop all RCPs, and ensure controlled bleedoff isolated.
C. 3 minutes or trip the reactor, stop all RCPs, and ensure controlled bleedoff isolated.
D. 10 minutes or commence a controlled shutdown.
Answer: B
The unit is operating at rated power. EW ‘A’ has been crosstied to NC due to a loss of BOTH NC pumps. ESS CLG WTR SYS TRBL ALARM (2A09A) is in alarm for Ess Cooling Water Surge Tank A level Hi-Lo. Containment Sump alarms have come in. EWA-UV-65 and EWA-UV-145 (EW to NC Crossties) have just auto-closed. No ESFAS actuations have occurred. Based on these conditions, 40AO-9ZZ03 (Loss of Cooling Water) directs the Operating Crew to: close the NC CNMT isolation valves, trip the reactor, stop all RCPs and …
A. isolate seal bleedoff.
B. restart essential chillers.
C. verify the isolation of EW to NC isolates the leak.
D. check containment RU monitors for activity.
Answer: A
Given the following plant conditions: Unit 1 is at 100% power. An RCS leak to the NC system is in progress. Which of the following would be indicative of an RCS leak into the letdown heat exchanger?
A. backpressure control valve closing.
B. backpressure control valve opening.
C. indicated letdown flow increasing.
D. NC flow from the heat exchanger decreases.
Answer: A
Essential Cooling Water (EW) will supply which of the following Nuclear Cooling Water (NC) loads when cross-tied to NC?
A. Normal Chillers.
B. Letdown heat exchanger.
C. Containment Normal AHUs.
D. Waste Gas Compressors.
Answer: A
Unit 1 is operating at rated power. An inadvertent CSAS occurs. The secondary operator has been directed to restore NCW to containment, overriding valves as necessary. Which one of the following describes the steps (in correct sequence) that must be taken to restore NCW to the containment?
A. Close NCN-UV-99, the cross connect the Train of ECW to supply the NCW priority loads.
B. Override and open the return valves (NCA-UV-402 and NCB-UV-403), then override and open the supply valve (NCB-UV-401).
C. Override and open the instrument air to containment isolation valve (IAA-UV-2) to permit operation of the NCW isolation valves.
D. Override and open the supply valve (NCB-UV-401) to pressurize the header, then override and open the return valves (NCA-UV-402 and NCB-UV-403).”
Answer: B
