Radioactive Collection,Processing,& Storage Subsystem(CH) Flashcards
What’re the three general areas Radioactive Collection is collected from ?
1.)Letdown flow diverted from VCT during feed&bleed operations from shutdowns,startups, & boron dilution
2.)RDT contents RC quality water collected from leak off, drains, & reliefs inside containment
3.)EDT contents consisting of leak drains & reliefs outside containment
Where is the discharge of the Reactor Drain Pumps directed towards ?
Directed to either the Pre holdup Ion Exchanger or bypasses it’s by 3way valve for PHIX inlet/bypass valve
What does the Pre-Holdup Ion Exchanger remove from RDT & EDT flow ? What temperature will the PHIX be bypassed ?
-Removes resin,lithium,& other ionic radio-nuclides
-The PHIX is automatically bypassed to prevent resin damage
Where does the PHIX outlet process flow go after it’s been processed through PHIX ?
-It either passes through gas stripper or bypasses it VIA the bypass valve
What is the gas stripper used for ?
-Removes gases to prevent buildup of gases in VCT or CVCS Holdup tank,minimizes release of radioactive fission product gases via vents or liquid discharge
Where is flow directed to after gas stripper ?
-Flow is is directed to CVCS HoldUp Tank
-Gas Stripper is normally bypassed
Where is Gas Stripper normally outlet flow path ?
Normally directed to VCT just downstream of VCT inlet valve, but could also be sent to CVCS Holdup
When Gas Stripper is in service, what will happen to outlet flow on High Level in VCT ? What happens to flow when VCT level resets ?
-Outlet flow is automatically diverted to CVCS Holdup Tank
-When VCT level resets, flow automatically returns to VCT
What status is the Gas Stripper for all 3 units ?
Gas Stripper is in long term shutdown and is NOT processing letdown flow
When there is high level conditions in VCT what is the normal flow path for letdown ?
-Normally flows through PHIX, bypassed Gas Stripper, and is directed to CVCS HUT for storage
Where is Radioactive waste water stored in until processed & sent to CVCS HUT ?
Either in Reactor Drain Tank or Equipment Drain Tank
When is sufficient capacity reach in CVCS HUT ?
Operations coordinates with chemistry to process contents with Boric Acid Concentrator
Is the Radioactive,Processing, & subsystem manually operated of automatically operated ?
Manually operated
What functions does the Reactor Drain Tank do ?
-Receives & condenses discharge from PZR safety valve to prevent it from being discharge to containment
-Receives thermal relief valve discharged from shutdown cooling & SI systems
-Gravity Drain from RCP vapor seal off
-Gravity drains & leakage from containment leakage
What is the RDT normally pressurized with ?
-Pressurized with 0.5psig nitrogen blanket for oxygen exclusion
What is minimum water volume used for inside RDT? Where does it come from ?
-Used for steam quenching of pressurizer safety valve discharge
-RMW from RMWT maintained minimum quench volume of 52% & used as cooling to lower RDT pressure
Why is the quench Volume of water necessary ?
RDT receives some high pressure & temp steam & is needed to cool and condense this steam to prevent Rupture Disc from breaking
What is the RDT rupture Disc setpoint ? What is it used to protect ?
Rupture disc setpoint at 120psid & protects RDT from stuck open PZR safety valve
Where does RDT vent to for High Pressure under 10psig? Where does it vent if pressure greater than 10psig ?
Under 10psig-Vents to Gaseous Radwaste system
Over 10psig- Vents to containment through RDT Atm. Vent Valve
What functions does the Equipment Drain Tank perform ?
-Receives gravity drain from Recycle Drain Header & Ion Exchanger Drain Header
-Receives gas stripper bypass for up to 30 mins between pumping
-Accepts discharge from misc. relief valves outside containment
What pressure is EDT at ?
Pressurized with 3psig nitrogen blanket for oxygen exclusion
How is the EDT protected from over pressure ?
Protected from overpressure by water relief that discharges to Non-ESF sump
What do the Reactor Drain Pumps used for ?
-Transfers contents from RDT or EDT,through Reactor Drain Filters, then through PHIX
What determines the processing path for RDT or EDT ,to either gas stripper or CVCS HUT ?
Based on chemical & radiological condition of collected water
What is the capacity of Reactor Drain Pumps ?
-Has capacity of 50gpm
What does interlock do for Reactor Drain Pumps ? What will automatically stop Reactor Drain Pumps ?
-Interlocks preventing both pumps from running at same time
-Stop automatically on low tank levels when respective pump suction valves are open
What is Pre Hold up Ion Exchanger for ?
-Provides supplemental purification of letdown with abnormally high levels of radionuclides or contaminants
-Reduces chemical contaminants prior to BAC processing
What is the flow rate the Prehold up Ion Exchanger is designed for ?
Designed for Maximum letdown flow rate of 150gpm
Where is PreHoldup Ion Exchanger spent resin sent to ?
Transferred to Radwaste Radwaste system
What is process fluid going to the Gas Stripper column heated up by ?
Heated by preheater & Heat Recovery Heat Exchanger by Auxiliary Steam on its way to stripper column
What is the Reboiler do to the small portion of water diverted from outlet flow of Stripper column ?
Heats up water again by Aux. Steam and converts it steam and directed back to stripper column
Where does the steam rise into inside stripper column ?
Steam rises through packing,condenses,& joins spray flow
When steam rises through gas stripper packing what happens ?
Combo of high temp,spraying,& impingement into packing & causes gases to rise above spray line into overhead condenser
What temperature is the gas temperature reduced below & what pressure is it maintained at ?
Temperature is reduced below 140F & marinated at 3-7psig pressure control valve & directed to Waste Gas Surge Tank & Gas Analyzer
After the gases are removed where does the degassed flow go to ? What temperature is it cooled back down to ?
1.)Flows to bottom of stripper column
2.)Through Heat Recovery Heat Exchanger & after cooler
3.)Cooled down to a maximum 130F
4.) Then flow to lvl control valve to CVCS Holdup Tank or VCT
What is the Heat Recovery Heat Exchanger used for ?
It’s used to pre heat incoming water to approx. 150F improving efficiency
What is the Pre Heater used for ? Where does steam drain to?
-Aux. Steam is used to heat incoming water to 240F
-Steam drains to Aux Steam Condensate Receiver Tank
What is the Stripper column used for inside Gas Stripper ?
Dissolved non condensable gases are removed within column
How does stripper column work ?
-Flow is ran through it & counter flow of saturated steam from Reboiler aids stripping process
-Stripped liquid is drawn into discharge pump suction
-Stripped gas enters overhead condenser
What is the Overhead condenser used for ? What is it cooled by ?
-Condenses entrained moisture in the gas leaving stripper column,while reducing gas volume
-Cooled by nuclear cooling water
What is the condensate pot used for ? What must be done to it periodically ?
Collects any residual moisture remaining in gas & must be periodically drained
When draining Condensate Pot why must you strictly adhere to procedure ?
Prevents contaminating room
What is the reboiler used for ?
Heats up water at bottom of column by Aux Steam which aid in gas stripping process
What does reboiler do for Gas Stripper while its in standby ? Where does Aux Steam drain to ?
-Maintains the column hot while it’s in standby
-Aux Steam drains to Aux Steam Condensate Receiver Tank
Where do the Gas Stripper Discharge Pumps transfer water to ?
Transfer water from gas stripper to CVCS HUT or VCT
What will auto start Gas Stripper Discharge pump ? What will trip the Pump ? What is pump rated for ?
-Auto starts on high column level
-System shutdown signal will trip pump
-Pumps are rated for 140gpm
What is the After Cooler after the Gas Stripper used for ? What cools the After Cooler ?
-Used to cool stripped liquid down to 130F prior to HUT or VCT
-After Cooler is cooled by Nuclear Cooling Water
During short term shutdown what status is Gas Stripper column ?
Gas Stripper Column is filled 50% and heated by reboiler due to Aux Steam still be distributed
What must be aligned to gas stripper during startup ?
-Aux. Steam & Nuclear Cooling Water
What considers the Gas Stripper is in long term shutdown ?
-Whenever pre heater or Reboiler steam valves are closed
-Stripper column is pressurized at 20psia with nitrogen
