Spray Pond Week Flashcards
What is the purpose of the spray pond system?
a) Remove heat from EW during normal or emergency shutdown
b) Remove heat from the Diesels when they are running
c) Reject heat to the essential spray ponds which dissipate heat to atmosphere
Draw the spray pond system.
make sure the drawing included:
DG fuel oil cooler, jacket water cooler, air after cooler, & lube oil cooler; EW HX; filtration equipment; Chem injection system components and injection lines; SP cross tie valves; major system isolation valves
What is meant by the term Ultimate Heat Sink?
Both A & B spray ponds cross tied together
Where does the essential spray pond pump take a suction from?
Its associated pond and discharges through its associated train heat loads.
What are the major heat loads on the spray pond system?
a) EWHX
b) coolers and heat exchangers on one DG
How does the spray pond maximize cooling of the water returned to it from its loads?
by spraying the water into the air through nozzles, allowing part to evaporate and the rest to fall back into the pond.
Why is pressure on the tube side of the EWHX maintained higher than the shell side?
so that if there is a leak, EW system water won’t enter the spray pond and contaminate the environment
Where does makeup water for the spray pond come from?
either DS (domestic water), or TB (Tower makeup and Blowdown)
What are the 6 chemicals added to the spray pond for chemistry control?
a) Hypochlorite (biologics)
b) Biocide (biologics)
c) sulfuric acid (pH control)
d) Copper Corrosion Inhibitor (corrosion)
e) Mild steel corrosion inhibitor (corrosion)
f) dispersant (scale and deposit control)
Where do the filter backwash pumps discharge to?
circ water intake structure
How long can either train maintain shutdown cooling conditions without makup for the ponds with them cross connected?
26 days
How long can the diesels run loaded and unloaded without spray ponds available?
15 minutes unloaded
2.6 minutes loaded
Where does the Hypo header originate?
WRF
What happens to the spray pond system on a loss of instrument air?
loss of remote level indication & level will need to be obtained locally
Which pumps in the spray pond system are powered by class power?
the spray pond pumps (PB)
Can the spray ponds with unit 1 be cross connected with unit 2 or 3?
no
How many headers and risers are there in the spray pond?
4 headers with 20 risers each.
How many nozzles are there per spray pond?
320
How is the source of makeup water determined?
Chemistry department via CCI and it depends on current spray pond chemistry conditions.
What are the differences between DS and TB as far as makeup water quality is concerned?
DS has more calcium and less biologics, but TB has less calcium and more biologics.
What is a last resort source of makeup water for the spray ponds?
Fire protection system
Where can the spray pond pumps be manually started from?
Control room or supply breaker
What automatically starts spray pond pumps?
Diesel start signal
SIAS, CSAS, AFAS (1 or 2), LOP
CRVIAS (control room ventilation isolation actuation signal) or CREFAS (CR essential filtration activation signal)
Does any equipment start when the spray pond pump starts?
Yes, the pump house exhaust fan starts
What is the automatic function on the spray pond filter pump?
it will auto stop on a low level in the associated spray pond
Why is the spray pond filter pump normally ran?
for feed and bleed as directed by chemistry. the pump takes a suction on the spray pond and discharges to the circ water intake canal at a rate determined by chemistry dept.
What will start the backwash sump pump if it’s in auto?
High level in the backwash sump and it will stop once the low level signal is received.
What are the spray pond corrosion test racks?
racks that are installed to monitor the corrosive effects of the spray pond water on piping and the HX.
Where are the spray pond cross tie valves actually located?
in the spray ponds approximately 6” off the bottom of the spray ponds
What two actions must take place within 24 hours of a loss of makeup water to the spray ponds?
a) if 2 trains of shutdown cooling are in service, secure one of them
b) open at least one cross tie valve
When is the spray pond normally operating?
When its associated diesel is running or when shutdown cooling is in operation.
Describe the spent fuel pool.
Stainless steel lined, concrete walled, 206,700 gallon pool
Where can makeup to the spent fuel pool come from?
RWT, LRS/RMT, CST, or in an emergency fire protection or DW via hoses.
What is the minimum boron concentration in the SFP?
Tech spec says 2150ppm, but we keep it between 4000-4400ppm
What is the high temperature alarm set point for the SFP?
High - 125F
Hi-hi - 145F
What is the low level alarm set point for the SFP?
137’6” low level
137’ low low level alarm
High level is at 138’2”
How are the fuel assemblies arranged in the SFP?
Checkerboard array in order to preclude inadvertent criticality
How can level in the SFP be determined?
1) by using the yard stick measuring device inside the fuel pool
2) the ultrasonic transceiver system
Why don’t you want the level in the SFP to be over 138.16’?
You could flood the fuel elevator cable tray and damage the motor or you could introduce water into the in core instrument tubing.
Why can’t the underwater lights be uncovered?
because without the water, they would burn out due to insufficient cooling
What is the PC (pool cooling and cleanup) system used for?
a) remove heat from the SFP, cask pit, fuel transfer canal, upper guide structure pit, and refueling pool
b) maintain water cleanliness and clarity in above areas
c) maintain water level above spent fuel in the SFP to provide adequate shielding during fuel handling operations
d) Provide clean up capability for the RWT
e) provide alternate source of borated water to CVCS
Where does the PC system take a suction from and discharge to in the SFP?
suction from the upper part, discharge to the lower part
Draw PC system.
verify you have:
2 PC cooling pumps, suction sources, discharge paths, 2 PCHX, cooling sources for HXs, and makeup sources
Describe the PC Cooling pumps.
Qty 2 of them, horizontal, centrifugal, 2000gpm, driven by 100HP class powered motor.