202.16 SGBD Flashcards
- 202.16 SGBD*
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Functions of SGBD
Maintain secondary side water chemistry w/in specs
Prevent the buildup of corrosion products
Reduce SG radioactivity levels
Provide the means of draining the SG secondary side, and
Maintain the correct environment during system wet lay-up and drained conditions
- 202.16 SGBD*
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SGBD Nozzle
~2 inch welded nozzle used to connect Blowdown piping to SG(s)
Connected to perforated “Sparger Pipe” to direct flow
Penetrates SG just above the tube sheet
After flow exits nozzle, pipe size is ~4 inches
- 202.16 SGBD*
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Hi-Flow Blowdown Valve
Also called Augmentation Flow Control Valve
May be used to raise flow after the continuous flow limit is reached on Main Blowdown Nozzle.
4 remotely operated AOV’s (1 per each S/G)
2” pneumatically operated valve
Draws water from Downcomer Region of SG
- 202.16 SGBD*
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Blowdown Isolation Valves
Provides remote manual/automatic blowdown flow isolation from it’s respective SG
4 remotely operated AOV’s - one for each SG
4” pneumatically operated isolation valve
Located in 21’ IVC above respective AFW Pump against south wall
Operated from MCR
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Blowdown Flow Control Valves
Used to control total blowdown flow from SG
4 remotely operated AOV’s - one per SG
3” pneumatically operated valve
Located in 10’ IVC near respective AFW Pump, just inside water-tight door, on west wall
Operated from MCR CP-018
- 202.16 SGBD*
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Flash Tank
Used to receive blowdown flow and provide the first level of heat recovery in the system.
(~ 30% of the flow flashes to steam as it enters the tank.)
Provides necessary Head to prevent flashing between the Flash Tank and Heat Exchangers
Located in 55’ TGB South-Central mezzanine, east of SGBD Heat Exchangers
- 202.16 SGBD*
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Regenerative Heat Exchangers
Used to recover heat and reduce the temperature of the blowdown to ~165°F with the demins bypassed by regulating condensate flow (120°F with the demins in service)
Shell and U-Tube HX
Located in 55’ TGB (south-central)
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Prefilters
Used to remove particulate matter from blowdown fluid to extend the life of the demineralizer resins
Two filters in parallel (original 25 micron)
Design Change allows any size or dummy filter to be installed
Normally the dummy filter is installed
Located 33’ MAB SGBD area (Old Truck Bay) south side in individual cubicles
- 202.16 SGBD*
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Demineralizers
Used to process SGBD for return to the Condensate System by removal of:
Suspended particulate
Corrosion Products
Dissolved Ionic Impurities
Radioactive Contaminants (Primary-to-Secondary Leak)
2 Mixed-Bed Demins normally in series
Located 33’ MAB SGBD area SW corner in separate elevated cubicles
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Recirculation Pumps
Used to recirculate water in SG during wet lay-up
4 pumps - one per SG
Single stage, horizontal, motor driven centrifugal pumps
Oil lubricated bearing between pump and motor
History has shown oil leaks are frequent
Located 10’ IVC directly across from respective AFW Pump Cubicles (outside water tight area
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Radiation Detectors
5 Radiation Monitors - 1 offline (RT-8043) and 4 adjacent to line
•Offline Monitor (RT-8043)
Measures the concentration of gamma producing nuclides to ensure that effluent levels are not exceeded
Used to prevent discharge of contaminated SGBD to Neutralization Basin and to determine demineralizer efficiency and depletion
May be aligned to Pre-filter Influent or Demineralizer Effluent
Located 41’ MAB Solid Waste Handling Area
•Adjacent to Line Monitors
Used to detect Primary-to-Secondary Leakage
4 monitors - one for each SG
Detectors in IVC between Containment Penetration & Containment Isolation Valve
RM-80(s) located in penetration space of EAB
SGBD A and SGBD C = 60’ EAB (A)8022, (C)8024
SGBD B and SGBD D = 10’ EAB (B)8023, (D)8025
- 202.16 SGBD*
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Signals that will cause automatic blowdown isolation
•4 signals will cause an Automatic Closure
SG LO-LO level (2 of 4 in any SG)
SI Auto initiation signal
AMSAC initiation signal
Reactor Trip (P-4) when Source Range is blocked
- allows the actuation if you are at power since source ranges would be blocked
- also prevents the isolation while shutdown
