Spray Pond Chemical Addition Flashcards
What is the purpose of the Spray Pond Chemical Addition system ?
Used to maintain our ultimate heat sink chemistry in order to optimize heat transfer of DG Coolers & Essential Cooling Water HEX
What is the reason for adding Sodium Hypochlorite?
-Minimize bacteria & algae growth
Why is Sulfuric Acid added to Spray Pond ?
Adjusted pH to prevent scale & corrosion
Why is dispersant added to Spray Ponds?
Provides colloidal suspension of scale forming ions, silt,& algae, for ease in filtering
Why is Biocide added to Spray Pond ?
Added to minimize Microbiological Influenced corrosion
Why is Copper Corrosion Inhibitor (CCI) added to the Spray Pond ? What is negatively affected by ?
-Sodium Tolytriazole is a film forming anole that binds with copper to protect heat exchangers tubes
-Negatively affect by chlorine & UV light
Why is Mild Steel Corrosion Inhibitor(MSCI) added to Spray Pond ?
Maintains protective film in HEX from residual concentrations
When is Mild Steel Corrosion Inhibitor addition started/stopped ?
Started- 15 minutes before securing SP pump
Stopped- 30 minutes after pump has been secured
Why does HMI have software interlocks ?
The software interlocks prevent undesired chemical interactions
Are HMI interlocks still active when manually adding chemicals ?
No, they’re not active & this could cause mixing chemicals which leads to localized high concentrations of chemicals
What is the High Flow Rate Valve(FCV) interlocked with ?
It’s interlocked with Spray Pond pump to prevent valve from opening, while the SP pump is running
Why is the Hypo additions High Flow Rate Valve interlocked with SP pump ?
If SP pump is running while adding high flow rate hypo, could cause hypos being pumped through DG & Essential cooling HEX which could cause damage due to corrosion
What’re the HMI interlocks to prevent Sodium Hypochlorite from interacting with Dispersant,CCI,MSCI?
Prevents incompatible Chemical Addition Pumps from starting in AUTO when Hypo is being added via automatic valve
What is the interlock to prevent Hypo from coming into contact with other chemicals if one of the Incompatible Chemical Pumps is started MANUALLY?
HMI software will auto close hypo automatic valves if Incompatible Chemical Pump starts during hypo addition
What’re the HMI interlocks to prevent Biocide from interacting with Dispersant,CCI,MSCI?
Interlocks to prevent incompatible Chemical Addition Pumps from being started while in AUTO, if Biocide is being added
What is the HMI interlock if a incompatible Chemical Addition Pump is started MANUALLY,while Biocide is being added ?
Biocide pump will trip, IF incompatible Chemical Addition Pump is started MANUALLY
What’re the HMI interlocks to prevent Dispersant from interacting with Biocide, CCI, Hypo?
Interlocks prevents incompatible Chemical Addition Pumps from AUTO starting,& Hypo Automatic valves is opened, DURING Dispersant addition
What does HMI interlock do when incompatible Chemical Addition Pump is started manually or Hype Automatic Valve is opened, DURING Dispersant addition ?
HMI interlock will trip Dispersant pump, IF incompatible Chemical Addition Pump is started manually OR Hypo automatic valve is opened
When can CCI only be added to Spray Pond ?
Can only be added when associated SP pump is running
What chemical is allows to be added with other chemicals ?
Sulfuric acid is only chemical allows to be added in conjunction with other chemicals
How many gallons are the Dispersant, CCI, MSCI, & Biocide tanks ?
1000 gallons for each tank
How does hanging lever detector work for the chemical tanks ?
It’s reverse indications as LVL does down with the float, it’ll pull the level indicator up higher
How’re chemicals added to Chemical Tanks ?
Utilities load a barrel onto forklift raised above tank and a hose is installed to gravity feed to Chemical Tank
How is the chemical fed to the associated Pump Skid ? What is the putout for each pump ?
-Chemical is gravity feed to two 18gph pumps for each spray pond
What is the cylinder on the pump skid used for ?
It’s filled and aligned to either pump for pump capacity testing
Where do the chemical pumps discharge to ?
They discharge into recirculation header
Are the chemical pumps on each pump skid able to be cross connect to each others spray pond?
Yes
What does the three position handswitch (Hand/Off/Off) on each chemical pump skid mean ?
Hand- Turns associated pump on &removes control from HMI PLC
Auto-Gives control of pump to HMI PLC
Off- Turns pump off & removes control from HMI PLC
What helps mix chemical into the recirculation header ?
A quill is used to create turbulent flow in Recirc header, which is then dispensed into ponds
What needs to be running for Chemical Addition pump to operate ?
Need Recirculation Pump must be running & aligned mechanically & electrically to be able to operate Chemical Addition Pump
How many Recirc pumps are usually running ?
-Two are usually running aligned to each spray pond
-Third pump is a backup which can be aligned to either spray pond
Where is Sodium Hypochlorite supplied from ? How is it transported ?
-Supplies to each unit from Water Resources
-Transports it through common header outside PA, which then it breaks off to each units common header, then the units common header is split into two headers
What’re the 5 valve entry points for Hypo into its spray pond ? What’re the valves rated for ?
-Two manual valves
One rated for .5gpm flow rate
Other rates for 10gpm flow rate
Three automatic air operated valves
-Low flow rate .25gpm
-Medium Flow Rate .50
-High flow rate 5gpm
What is different about Low Rate FCV than the other valves ?
Can also be operated via clutch & manual hand wheel
How big is the acid chemical tank ?
2500gallons and it’s a double walled tank
What does the Acid Chemical Tank feed ?
It feeds the Chemical Addition skids that has two pumps rated for 6gph & will discharge directly to SP
What is the HMI PLC used for ?
It is used on the Spray Ponf Chemical Addition subsystem
When must the schedule for the HMI PLC for the Chemical Addition system be verified by the area operator ?
-Must be verified by AO within 3 hour window
-Starting 2 hours before & end on hour AFTER Trigger Time for daily chemical addition
What is the alarm associated with Chemical Addition system ?
A local yellow strobe & horn on outside of building
What do the HMI alarm on, for the Chemical Addition system ?
-High & Low level on tanks
-Any non-normal condition from PLC
-Pump Skid level alarm
