Radioactive Collection,Processing,& Storage Subsystem(CH)

Question 1

What’re the three general areas Radioactive Collection is collected from ?

Answer 1

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

Question 2

Where is the discharge of the Reactor Drain Pumps directed towards ?

Answer 2

Directed to either the Pre holdup Ion Exchanger or bypasses it’s by 3way valve for PHIX inlet/bypass valve

Question 3

What does the Pre-Holdup Ion Exchanger remove from RDT & EDT flow ? What temperature will the PHIX be bypassed ?

Answer 3

-Removes resin,lithium,& other ionic radio-nuclides
-The PHIX is automatically bypassed to prevent resin damage

Question 4

Where does the PHIX outlet process flow go after it’s been processed through PHIX ?

Answer 4

-It either passes through gas stripper or bypasses it VIA the bypass valve

Question 5

What is the gas stripper used for ?

Answer 5

-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

Question 6

Where is flow directed to after gas stripper ?

Answer 6

-Flow is is directed to CVCS HoldUp Tank
-Gas Stripper is normally bypassed

Question 7

Where is Gas Stripper normally outlet flow path ?

Answer 7

Normally directed to VCT just downstream of VCT inlet valve, but could also be sent to CVCS Holdup

Question 8

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 ?

Answer 8

-Outlet flow is automatically diverted to CVCS Holdup Tank
-When VCT level resets, flow automatically returns to VCT

Question 9

What status is the Gas Stripper for all 3 units ?

Answer 9

Gas Stripper is in long term shutdown and is NOT processing letdown flow

Question 10

When there is high level conditions in VCT what is the normal flow path for letdown ?

Answer 10

-Normally flows through PHIX, bypassed Gas Stripper, and is directed to CVCS HUT for storage

Question 11

Where is Radioactive waste water stored in until processed & sent to CVCS HUT ?

Answer 11

Either in Reactor Drain Tank or Equipment Drain Tank

Question 12

When is sufficient capacity reach in CVCS HUT ?

Answer 12

Operations coordinates with chemistry to process contents with Boric Acid Concentrator

Question 13

Is the Radioactive,Processing, & subsystem manually operated of automatically operated ?

Answer 13

Manually operated

Question 14

What functions does the Reactor Drain Tank do ?

Answer 14

-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

Question 15

What is the RDT normally pressurized with ?

Answer 15

-Pressurized with 0.5psig nitrogen blanket for oxygen exclusion

Question 16

What is minimum water volume used for inside RDT? Where does it come from ?

Answer 16

-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

Question 17

Why is the quench Volume of water necessary ?

Answer 17

RDT receives some high pressure & temp steam & is needed to cool and condense this steam to prevent Rupture Disc from breaking

Question 18

What is the RDT rupture Disc setpoint ? What is it used to protect ?

Answer 18

Rupture disc setpoint at 120psid & protects RDT from stuck open PZR safety valve

Question 19

Where does RDT vent to for High Pressure under 10psig? Where does it vent if pressure greater than 10psig ?

Answer 19

Under 10psig-Vents to Gaseous Radwaste system
Over 10psig- Vents to containment through RDT Atm. Vent Valve

Question 20

What functions does the Equipment Drain Tank perform ?

Answer 20

-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

Question 21

What pressure is EDT at ?

Answer 21

Pressurized with 3psig nitrogen blanket for oxygen exclusion

Question 22

How is the EDT protected from over pressure ?

Answer 22

Protected from overpressure by water relief that discharges to Non-ESF sump

Question 23

What do the Reactor Drain Pumps used for ?

Answer 23

-Transfers contents from RDT or EDT,through Reactor Drain Filters, then through PHIX

Question 24

What determines the processing path for RDT or EDT ,to either gas stripper or CVCS HUT ?

Answer 24

Based on chemical & radiological condition of collected water

Question 25

What is the capacity of Reactor Drain Pumps ?

Answer 25

-Has capacity of 50gpm

Question 26

What does interlock do for Reactor Drain Pumps ? What will automatically stop Reactor Drain Pumps ?

Answer 26

-Interlocks preventing both pumps from running at same time -Stop automatically on low tank levels when respective pump suction valves are open

Question 27

What is Pre Hold up Ion Exchanger for ?

Answer 27

-Provides supplemental purification of letdown with abnormally high levels of radionuclides or contaminants -Reduces chemical contaminants prior to BAC processing

Question 28

What is the flow rate the Prehold up Ion Exchanger is designed for ?

Answer 28

Designed for Maximum letdown flow rate of 150gpm

Question 29

Where is PreHoldup Ion Exchanger spent resin sent to ?

Answer 29

Transferred to Radwaste Radwaste system

Question 30

What is process fluid going to the Gas Stripper column heated up by ?

Answer 30

Heated by preheater & Heat Recovery Heat Exchanger by Auxiliary Steam on its way to stripper column

Question 31

What is the Reboiler do to the small portion of water diverted from outlet flow of Stripper column ?

Answer 31

Heats up water again by Aux. Steam and converts it steam and directed back to stripper column

Question 32

Where does the steam rise into inside stripper column ?

Answer 32

Steam rises through packing,condenses,& joins spray flow

Question 33

When steam rises through gas stripper packing what happens ?

Answer 33

Combo of high temp,spraying,& impingement into packing & causes gases to rise above spray line into overhead condenser

Question 34

What temperature is the gas temperature reduced below & what pressure is it maintained at ?

Answer 34

Temperature is reduced below 140F & marinated at 3-7psig pressure control valve & directed to Waste Gas Surge Tank & Gas Analyzer

Question 35

After the gases are removed where does the degassed flow go to ? What temperature is it cooled back down to ?

Answer 35

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

Question 36

What is the Heat Recovery Heat Exchanger used for ?

Answer 36

It’s used to pre heat incoming water to approx. 150F improving efficiency

Question 37

What is the Pre Heater used for ? Where does steam drain to?

Answer 37

-Aux. Steam is used to heat incoming water to 240F -Steam drains to Aux Steam Condensate Receiver Tank

Question 38

What is the Stripper column used for inside Gas Stripper ?

Answer 38

Dissolved non condensable gases are removed within column

Question 39

How does stripper column work ?

Answer 39

-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

Question 40

What is the Overhead condenser used for ? What is it cooled by ?

Answer 40

-Condenses entrained moisture in the gas leaving stripper column,while reducing gas volume -Cooled by nuclear cooling water

Question 41

What is the condensate pot used for ? What must be done to it periodically ?

Answer 41

Collects any residual moisture remaining in gas & must be periodically drained

Question 42

When draining Condensate Pot why must you strictly adhere to procedure ?

Answer 42

Prevents contaminating room

Question 43

What is the reboiler used for ?

Answer 43

Heats up water at bottom of column by Aux Steam which aid in gas stripping process

Question 44

What does reboiler do for Gas Stripper while its in standby ? Where does Aux Steam drain to ?

Answer 44

-Maintains the column hot while it’s in standby -Aux Steam drains to Aux Steam Condensate Receiver Tank

Question 45

Where do the Gas Stripper Discharge Pumps transfer water to ?

Answer 45

Transfer water from gas stripper to CVCS HUT or VCT

Question 46

What will auto start Gas Stripper Discharge pump ? What will trip the Pump ? What is pump rated for ?

Answer 46

-Auto starts on high column level -System shutdown signal will trip pump -Pumps are rated for 140gpm

Question 47

What is the After Cooler after the Gas Stripper used for ? What cools the After Cooler ?

Answer 47

-Used to cool stripped liquid down to 130F prior to HUT or VCT -After Cooler is cooled by Nuclear Cooling Water

Question 48

During short term shutdown what status is Gas Stripper column ?

Answer 48

Gas Stripper Column is filled 50% and heated by reboiler due to Aux Steam still be distributed

Question 49

What must be aligned to gas stripper during startup ?

Answer 49

-Aux. Steam & Nuclear Cooling Water

Question 50

What considers the Gas Stripper is in long term shutdown ?

Answer 50

-Whenever pre heater or Reboiler steam valves are closed -Stripper column is pressurized at 20psia with nitrogen