SALEM
SALEM STUDY SYSTEM
Systems > Feed & Condensate

Feed & Condensate

⚠️ DRAFT

Feed & Condensate

Function

The feedwater system supplies heated feedwater from the condensate system to the steam generators. The condensate system collects condensed steam from the main condensers and pumps it through feedwater heaters to the feedwater pumps. (UFSAR 10.4)

Main Feedwater

  • Feedwater pumps (turbine-driven) supply feedwater through feedwater regulating valves to steam generators
  • Feedwater temperature at full power: 432.8°F
  • SG level controlled by feedwater regulating valves

SG Level Control

  • Below P-7 (low power): Single-element control (SG level only)
  • Above P-7 (at power): Three-element control (steam flow, feed flow, SG level) (UFSAR 7.7.2.6)

Feedwater Isolation

Actuated by:

  1. Safety Injection signal
  2. 2/3 Hi-Hi SG level (P-14) — trips all FW pumps, closes FW valves, trips turbine
  3. Low auctioneered Tavg AND reactor trip (P-4)

Closes main FW control valves (fast closure), bypass valves, and inlet stop valves. (UFSAR T7.2-1)

Exam — 2018 Q37
21CN22 and 23CN22 (LP FW Heater Inlet Control Valves) spuriously close: 2CN45 modulates open to maintain <65 psid across 21 and 22 LP Heaters. With CN45 modulated open (bypassing heaters), feedwater temperature lowers → reactor power rises (cooler feedwater = positive reactivity from MTC). CN22 valves have indications ONLY in the Control Room — no controls. The crew can NOT open 21CN22 or 23CN22 from the Control Room. Other CN valves (2CN45, 2CN47) CAN be operated from the Control Room — do not assume all CN valves have Control Room controls.
Exam — 2023 Q8
High level in 21A Low Pressure feedwater heater closes ONLY the associated 21CN22 inlet valve (not all three LP FW heater strings). With one LP FW heater string bypassed, cooler feedwater enters the reactor, raising actual reactor thermal power due to positive MTC effect. NI power indication reads lower than actual because cooler moderator provides shielding to PR NIS. Reactor power should be determined from RCS delta-Ts, and turbine load reduced to prevent exceeding thermal power limits.
Exam — 2023 Q42
BF19 (MFW Regulating Valve) fails fully OPEN → SG level rises → SG High Level Trip (P-14) actuates at 2/3 NR levels ≥67% on any one SG. P-14 trips the main turbine, which causes an auto reactor trip AND actuates Feedwater Isolation (closes all BF13s, BF19s, BF40s, trips both SGFPs, and trips the Main Turbine). Note: FW Interlock alone only closes the BF19s and BF40s — FW Isolation is the broader actuation.
Exam — 2022 Q44
FW Isolation vs FW Interlock: SG Hi-Hi Level (P-14) triggers FW Isolation — trips SGFPs AND closes BF13s, BF19s, BF40s, AND trips Main Turbine. FW Interlock (P-4, reactor trip + low Tavg) ONLY closes BF19s and BF40s — does NOT trip SGFPs and does NOT close BF13s. FW Isolation is the broader actuation (trips pumps + closes all valves). FW Interlock is narrower (only closes regulating and bypass valves). Do not confuse the two.
Exam — 2022 Q45
SG program level above 20% power is 44% NR. With SG NR level at 45% (above 44% program), BF19 (FW Bypass Regulating Valve) demand decreases — digital FW system throttles BF19s closed to reduce feedwater flow and lower SG level to program. 44% is the program setpoint above 20% power — do not confuse with 50% or other SG level setpoints.
Exam — 2022 Q13
Main feedwater line break vs steam line break: FW line break causes SG levels to lower FASTER (direct loss of feedwater inventory). RCS cooldown is LESS than an equivalent steam line break (loss of FW doesn't involve removal of latent heat as steam break does). FW break generates Low-Low SG Level reactor trip; post-trip RCS Tavg rises due to decreased heat transfer in the affected SG.
Exam — 2019 Q17
SGFP trip at >70% power — AB.CN-0001 immediate actions: MANUAL Main Turbine load reduction to a MAXIMUM of 66% Turbine Power at a MAXIMUM of 15%/MIN. 50% is incorrect (each SGFP does not provide exactly 50% flow). 30%/MIN is the automatic stator cooling water loss runback rate, NOT the AB.CN-0001 manual load reduction rate.
Exam — 2019 Q18
SGFP Turbine Overspeed Trip: SGFP turbines have an overspeed trip at 6080 rpm. SGFP design capacity is 5500 rpm. Do not confuse with Main Turbine overspeed trips: 108% = 1944 rpm or 110% = 1980 rpm. The SGFP turbine operates at much higher RPM than the Main Turbine.

Condenser and Condensate

  • Main condensers receive exhaust steam from turbine and steam dump
  • Condensate pumps deliver condensate through feedwater heaters to feedwater pumps
  • Condenser serves as heat sink for steam dump during load rejection (UFSAR 10.4)
Exam — 2020 Q93
Condensate pump trip at 100% power: 2CN47 (23/24/25 Heater String Bypass valve) controls automatically to maintain SGFP suction pressure > 265 psig. Per AB.CN-0001, open 21-23 CN108 (Polisher Bypass Valves) if SGFP suction pressure < 320 psig. Power reduction per Attachment 2 to a maximum of 85%. 265 psig is the CN47 auto-control setpoint, NOT the CN108 opening threshold. 75% is the IOP-4 third condensate pump start power level, NOT the AB.CN-0001 load reduction limit.

Tech Spec LCOs

Exam — 2023 Q60
CW waterbox tube leak alarms: a gross tube leak is confirmed by Dissolved Oxygen Hi, Condensate Pump Disch Sodium Hi, and Hotwell Outlet Conductivity Hi. Hydrazine Lo is NOT expected from a CW tube leak — river water intrusion does not impact hydrazine concentration.
Exam — 2023 Q64
SGFP trip response: DEHC automatically initiates turbine runback at 200% per minute to 66% power. 2CN47 (23/24/25 Heater String Bypass valve) immediately opens and the polisher is bypassed. Manual runback from the DEHC panel uses 15% per minute rate. On a condensate pump trip, 2CN47 only opens if SGFP suction pressure drops below 320 psig; on a SGFP trip, 2CN47 opens regardless of suction pressure.
Exam — 2023 Q74
Condensate depression: the temperature difference between the condenser saturation temperature and the actual condensate temperature. Decreasing condensate depression (e.g., 5°F to 2°F) raises thermal efficiency (hotter feedwater means SGs add less sensible heat) but moves the condensate pumps closer to cavitation (less subcooling = less NPSH at pump suction).
JPM — 2023 Sim-e
EOP-FRHS-1 condensate pump feed: establish condensate flow to selected SG by opening BF40 (Main Feed Bypass Valve, locally), BF13 (Feed Water Isolation Valve), 21 and 22 CN48 (Feed Pump Bypass Valves), and closing 21 and 22 CN32 (Feed Pump Suction Valves). Verify condensate flow established with WR level rising.
JPM — 2022 Sim-e
Loss of SGFP at >70% power: auto turbine runback fails. Per AB.CN-0001 Step 2.3.1.B: manually initiate load reduction at DEHC panel — toggle %/HR to %/MIN, set ramp rate to 15%/min, setter to 66%. Also: rods fail to insert in AUTO during downpower — take rods to MANUAL and insert at 48 steps/min to control Tavg.
Exam — 2022 Q58
Ovation (ADFCS) steam pressure channel failure: Ovation uses one pressure channel from each SG (4 total) into a Medium Signal Select (MSS) algorithm. If one SG steam pressure channel fails HIGH, the associated MS10 (atmospheric dump) loop switches to MANUAL control (OHAs G-7 ADFCS Alternate Action and G-15 ADFCS TRBL). The MSS algorithm selects a good input for the remaining MS10 loops — other MS10s remain in AUTO. A single pressure channel failure does NOT open the MS10 or cause ALL MS10s to swap to manual.
Scenario — 2022 #3
Condensate recovery in EOP-FRHS-1 after loss of all AFW. Both SGFPs tripped due to auto SI following main turbine failure to trip. Crew resets SI/Phase A/Phase B, opens CA330s. Selects one SG for depressurization to < 575 psig using MS10. Dispatches operator to open BF40 or BF19 (120 ft TGA). Opens BF13, opens CN48 (SGFP bypass valves), closes CN32 (SGFP suction valves). Condensate flow established when SG pressure is around 600 psi. Validation note: approximately 10 minutes to depressurize via MS10, condensate flow visible at 5-6% WR rising.
Exam — 2020 Q60
ADFCS (Ovation) SG NR Level Quality Alarm response: with two inputs in Quality Alarm (BAD) for one SG (e.g., Channel I failed HIGH and Channel II failed LOW), the system initiates OHA G-7 (ADFCS ALTERNATE ACTION) and transfers BOTH BF19 and BF40 for that SG to MANUAL. Only one channel failure = single Quality Alarm — no ADFCS Alternate Action. With TWO bad channels on the same SG, the ADFCS cannot determine a valid level and transfers BF19 and BF40 to MANUAL. SGFPs do NOT shift to MANUAL (that was the previous digital feed system design). Other SGs' controllers remain in AUTO.
Exam — 2020 Q45
BF19 (Main FW Regulating Valves) on loss of all station air: BF19s start to close at 80 psig control air header pressure. BF19s receive air from Unit 1 via redundant Lunkenheimer air panels, but on total loss of ALL station air, no backup supply is available. ECACs cannot supply BF19 CA headers due to a check valve isolating the turbine building headers. Per AB.CA-0001 CAS: if both CA headers < 80 psig or BF19s closing with inability to control SG level → trip the reactor.
Exam — 2020 Q44
On trip of both SGFPs, only the MDAFW pumps auto-start. The TDAFW pump does NOT auto-start on SGFP trip — it requires 2/3 Lo-Lo level in 2/4 SGs (14% NR), RCP bus undervoltage, or manual start. Per S2.OP-SO.CN-0002, a removed-from-service SGFP is placed in the tripped condition, satisfying half of the "trip of both SGFPs" auto-start logic.
Scenario — 2020 #4
21 SGFP trips on high thrust bearing oil pressure at 2% power. CRS enters AB.CN-0001. PO reports first-out annunciator: thrust bearing oil pressure high trip locked in and will not clear. RO reduces reactor power to <4% by inserting control rods. AFW auto-start fails — crew manually starts motor-driven AFW pumps.
Scenario — 2020 #5
23BF19 feedwater reg valve fails closed (ramped over 1 minute) at 85% power. OHA alarms: G-15 ADFCS TRBL, G-23 21/22 SGFP SPEED DEVIATION, 23 SG Program Setpoint Deviation. Manual control attempts unsuccessful. Both SGFPs trip on SI actuation following reactor trip — SGFPs NOT available during EOP-FRHS-1. Condensate recovery path: open selected SG BF40 or BF19 locally (120 ft elevation TGA), open BF13, open 21 and 22 CN48 (SGFP bypass valves), close 21 and 22 CN32 (SGFP suction valves). Feed flow established when SG pressure depressurized to <575 psig.
Exam — 2018 Q17
SGFP suction pressure trip setpoints: SGFP trips when suction pressure < 215 psig for 10 seconds (time-delayed trip). Instantaneous SGFP trip on low suction pressure at < 190 psig (no time delay). At 200 psig (between 190 and 215), the 10-second delay timer applies. After SGFP trip at >70% power, turbine runback to 66%. Trap: 50% is incorrect — each SGFP does NOT provide exactly 50% total flow. The 66% runback target confirms the SGFPs are not 50/50 load-shared.

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