Main Condenser, Condensate and Feedwater Tech Specs

Question 1

T.S. 3.7.3 Main Feedwater Regulating Valves (MFRVs) and MFRV Bypass Valves

Answer 1

T.S. 3.7.3 Main Feedwater Regulating Valves (MFRVs) and MFRV Bypass Valves

Two Main MFRVs and two MFRV bypass valves shall be OPERABLE

During Modes 1,2 and 3 EXCEPT when

• Closed and deactivated or,
• Manually isolated

One or more MFRVs or MFRV bypass valves inoperable

Close or isolate inoperable MFRV(s) or MFRV bypass vale(s) within 8 hours AND, Verify inoperable MFRV(s) or MFRV bypass valves(s) is closed or isolated.

• Use manual operator and pin to close MFRV
• Close Main Feed Stops or Main Feed Stop Check valves.
• Can take credit for closing Main Feed Stop from Control Room using the Hand Switch
• Close other manual valves that have same effect.
• Once manually isolated, still inoperable but are meeting the LCO 3.7.3.A requirements

Effectively limits the plant to Mode 3 unless:

MFRV Bypass is inoperable. Manually isolating the bypass does not preclude plant operation with the MFRV operable.

Plant is difficult to control at <15% power on MFRV

General Basis

Ensures valves will isolate MFW flow to S/Gs on MSLB.

• Termination of feedwater to the affected steam generator limits the mass and energy release inside containment
• Requires closure on SG low pressure on respective S/G
• Requires closure on CHP
• Requires isolation times within specification (≤ 22 seconds)
• Requires the MFRV and /or MFRV Bypass valve close on an isolation signal
• Failure of the isolation signal also impacts these valves, therefore MFRV and /or MFRV Bypass valves are supported system (Supported by 3.3.4).

Question 2

T.S. 3.7.6 Condensate Storage and Supply

Answer 2

T.S. 3.7.6 Condensate Storage and Supply

Combined useable volume of the Condensate Storage Tank (CST) and Primary Makeup Storage Tank (T-81) shall be ≥ 100, 000 gallons.

During Modes 1, 2, 3 and 4 when SG are relied upon for heat removal.

Once on SD Cooling, no longer applicable

Requirements are met if:

• T-2 > 71%
• T-81 > 83%

General Basis

The Condensate Storage and Supply provides condensate to remove decay heat and cool down the plant following all events in the accident analysis.

The CST and T-81 must contain sufficient cooling water to remove decay heat for eight hours following a reactor trip from 2580.6 MWth.

The analysis assumption is 30 minutes at MODE 3, steaming through the MSSVs followed by a cooldown to Shutdown Cooling (SDC) entry conditions at the design cooldown rate (assumes SG(s) Operability not affected).

Question 3

ORM 3.17.6 Other Instrumentation

Answer 3

ORM 3.17.6 Other Instrumentation

The Instrument channels listed in Table 3.17.6 shall be OPERABLE

Feedwater flow and temperature indication only required above 15% RTP

Item 4 – Main Feedwater Flow

Action 4 – One Main Feedwater flow channel inoperable, within 24 hours provide alternate means of flow monitoring (PPC)

Item 5 - Main Feedwater Temperature

Action 5 – One Main Feedwater temperature channel inoperable, within 24 hours provide alternate means of temperature monitoring (TE-0706 (TE-0708), REC-C11-03 and PPC points)

General Basis

Required for daily calorimetric calculation (heat balance).

Operation can continue if either flow or temperature indications are lost provided alternate indication can be provided to allow completion of the daily calorimetric calculation