(CH)- Boric Acid Concentrator Flashcards
What is the purpose of the BAC feed valve, CH-287?
A modulated fail-closed valve which maintains a flash tank Setpoint level via the flash tank level indicator controller LIC-287
The setpoint corresponds to a predetermined flash tank level and is dialed into LIC-287 at the control panel
What’s included in the BAC concentrate loop?
The concentrate pumps, concentrate heater, flash tank, interconnecting piping, valves, instrumentation and controls
Concerning the BAC Concentrate Loop, what would you expect to see operating during normal ops?
Both of the 1500 gpm concentrate pumps operate in parallel to provide the 3000 gpm process fluid circulation through the heater into the flash tank
In regards to the BAC Concentrator, what effect on its operation will occur upon a loss of either circulating pump?
Will not cause a concentrator shutdown or loss in processing capacity, but continued single pump operation will increase the tendency of the heater to foul
Two check valves are installed downstream of each pump to preclude backflow during single pump operation
Concerning the check valves downstream of the BAC Concentrate circulating pumps, why is there a 3/8” perforation?
To provide limited concentrate recirculation during single pump operation, which will keep the non-operating pump sufficiently heated to prevent precipitation of solids
Approximately how hot will the concentrate be when it enters the flash tank in the BAC system?
240F
What system provides cooling to the BAC Concentrate cooler?
Nuclear Cooling
Why do we backwash two of the three demisters in the BAC flash tank?
Assists in removing any boric acid or other impurities which are entrained in the vapor stream
How can I remove tritium from the BAC skid?
Distillate steam form the Vapor Separator may be directly discharged to plant piping through CHN-V282 and out the plant vent
What would be the adverse effect of using insignificant flow from the steam vent in the BAC system?
Will starve the distillate system and require the use of RMW to supplement distillate water for Distillate Flush functions on the skid
What is the purpose of the CVCS Holdup Tank and what is its capacity?
Stores all recoverable Reactor Coolant and provides the NPSH required for operation of the Holdup Pumps
holdup capacity for recycle waste water produced during refueling and power ops
hold up capacity for drains, reliefs and leakage collected in the RDT and EDT
550,000 gallon capacity
What temperature is maintained in the CVCS Holdup Tank and how is it maintained?
Maintained above 60F by two sets of redundant 25 kW heaters
At what level in the CVCS Holdup Tank will the BAC be used to begin processing?
17 feet (hi alarm level)
Where does the CVCS Holdup tank vent to? Where is this tank located?
Fuel Building Ventilation (exhaust header)
RCA yard next to RMWT
What is the basis of the CVCS Holdup Tank capacity?
Designed to store all recoverable water from back-to-back cold shutdowns to 5% subcritical and subsequent startup at 90% core life
What is the purpose of the CVCS Holdup Tank Pumps?
Two pumps to transfer the contents of the CVCS Holdup tank to the BAC
recirculate the CVCS holdup tank contents
What is the purpose of the recirculation line on the CVCS Holdup Tank pumps?
Recirculation line goes back to the HUT to prevent dead heading the pump when the BAC inlet valve cycles
What is the capacity of the CVCS Holdup Tank Pumps?
50 gpm each
Where are the CVCS Holdup tank Pumps operated and how are they interlocked?
Controlled manually at the CVCS hold up tank pump room next to the HUT
Interlocked to prevent both pumps from operating simultaneously
What would stop the CVCS Holdup tank Pumps automatically?
Lo-lo CVCS holdup tank level
High BAC level
Diversion of letdown flow to the Pre-Holdup Ion Exchanger when the contents are being purified