SP-Spray Pond Chemical Addition subsystem

Question 1

What is the purpose of the Spray Pond Chemical addition system?

Answer 1

To mainttain our Ultimate Heat sink chemistry within specified parameters to optimize heat transfer of DG coolers and EC HX

Question 2

What chemicals are added to the Spray Ponds?

Answer 2

Sodium Hypoclorite-Minimize bacteria and algae growth
Sulfuric Acid-lowers pH minimize scale&corrosion

Question 3

What chemicals are added to the Spray Ponds?

Answer 3

Sodium Hypoclorite-Min bacteria and algae
Sulfuric Acid-lowers pH min scale&corrosion
Dispersant-colloidal suspension of scale forming ions
Biocide-min Microbio corrosion
Copper Corrosion Inhibiter (CCI/TTA)-sodium tolytriazole film bonds to copper to protect HX tubes (UV light neg affects)
Mild Steel Corrosion Inhibiter (MSCI)-protective film in HX tubes

Question 4

How does Mild Steel Corrosion Inhibiter work?

Answer 4

MSCI addition is started 15 min before and stopped 30 min after SP pump stops.

Question 5

What is the purpose of the Human Machine Interface sofware interlocks when adding chemicals to the SP?

Answer 5

Prevents undesired chemical interactions.

Question 6

What is the interlock between the High Rate Flow control Valve (FCV) and the Spray Pond Pump?

Answer 6

The SP pump must be stopped B4 high flow of Sodium Hypochlorite can be added to avoid damage to HX.
Hypo incompatible with Dispersant, CCI, and MSCI

Question 7

What is the interlock between Biocide and the Spray Pond Pump?

Answer 7

Biocide is incompatible with DDI, Dispersant, and MSCI. Chem add pump will stop if trying to add chemical together.

Question 8

What is the interlock between Dispersant and the Spray Pond Pump

Answer 8

Dispersant is incompatible with Bioide, CCI, and Hypo

Question 9

What is the interlock between Copper Corrosion Inhibitor (CCI) and Spray Pond Pump?

Answer 9

Can only be added when SP pump running. CCI is incompatible with Biocide, Dispersant, MSCI, and Hypo.
Chem add pump and hypo pumps will not run during this time

Question 10

What is the interlock between Mild Steel Corrosion Inhibitor (MSCI) and the Spray Pond Pump?

Answer 10

MSCI is incompatible with Boiocide, CCI, and hypo.
HMI software will stop the MSCI add pump if an incompatible pump is manually started.

Question 11

What is the effect of adding Sulfuric Acid and other chemicals?

Answer 11

No limitations. Sulfuric acid is the ony chemical we use that can be added with any other chemical.

Question 12

How do we store Dispersant, Copper Corrosion Inhibitor, Mild STeel Corrosion Inhibitor, and Biocide?

Answer 12

WE have 4 1000 gal tanks with float level indicator that is reverse indicating. Level also maintained by HMI panel. Chemical added by Utilities

Question 13

What is the design of the chemical addition pump skid?

Answer 13

Chemicals are gravity fed to the associated 18gpm ppump 1 for each SP. The piping can be aligned to the discharge or the suction when nec.

Question 14

What the design of the Pump Local Control Panel?

Answer 14

(Hand/Off/Auto) 1 for each pump.
Hand-manual start
Auto-HMI PLC
Off-off no HMI PLC control
Chems discharged from the chem add pump to the recirc for fia a quill where turbulent flow is created. You MUST rund the recirc pumps with the chem add.

Question 15

What is the design of the Recirculating Pumps?

Answer 15

3 SP recirc pump for chem add subsystem. 2 are usually running with 1 in standby.

Question 16

What is the flow path when adding chemicals to the Spray Ponds?

Answer 16

Recirc pumps supploed from discharge of the SP fliter pump, flow to chem add pump house, chems added 1@a time, back to the SP at the suction of the SP pump.

Question 17

What is different about unit 3 chemical addition?

Answer 17

New building and storage tanks built for longevity.

Question 18

What is the flow path for the hypochlorite addition into the Essential Spray Ponds?

Answer 18

Sodium Hypochlorite (Hypo) is supplied by WRF through a common header

Question 19

What is the flow path for the hypochlorite addition into the Essential Spray Ponds?

Answer 19

Sodium Hypochlorite (Hypo) is supplied by WRF through a common header to either one of the three units. At the unit another header splits in two for each train. The it had 5 points of entry.

Question 20

What are the Manual valves for the Hypo addition to the SP?

Answer 20

SPN-V492, -V95 are rated for 0.5 gpm flow
SPN-V491, -V494 are rated for 10 gpm flow.

Question 21

What are the Automatic valves for the Hypos addition to the sP?

Answer 21

SPN-V282, -V285 are rated low 0.25 gpm
SPN-V283, _V286 are rated medium 0.5 gpm
SPN-V284, -V287 are rated high 5 gpm

Question 22

How are automatic valves for the Hypo addition normally and alternately operated?

Answer 22

HMI PLC normally operates the auto valves, but the low flow valve can be op via clutch and manual handwheel.

Question 23

What is the flow path of acid to the Essential Spray Ponds?

Answer 23

Acid chmical addition tank is 2500 gal, double walled tank, feeds chemical additon skid, acid pumps discharge directly into SP at 6 gph (very low).

Question 24

What is the purpose of the Chemical Addition subsystem HMI machine?

Answer 24

It is the programmable logic controller for the SP

Question 25

What is the design of the Chemical addition subsystem HMI?

Answer 25

Touch screen that Chemistry and Ops interact with daily. Chemistry inputs sched and AO’s verify. Must be verified in 3 hour window. 2hrs b4 start and end 1 hr after start.

Question 26

What are the alarms associated with the Chemical Addition System?

Answer 26

A local yellow strobe and horn on building. Alarms on High/Low level on tanks, any non-normal condition from the PLC, or a pump skid level alarm. Red light was abandoned.