2. ACADs (08-006) Covered Keywords Description Supporting Material 4.2.7.15

3. 2

4. TitleExtraction Steam, Heater Vents & Drains Number Revision 1 Program NUET 1260 Author Rob Thomas Date Approved: Date: Lesson Format PowerPoint Presentation Materials Computer Projector and Simulator software Evaluation Written exam in conjunction with other lesson plans, presentations, and handouts. References V-LO-TX-18301 AT-1260-LP-Extraction Steam Instructor Guidelines 5/23/11 AT-1260-PP 3

5. Rev NoDateReason for Revision Author’s Initials Supv’s Initials 4

6. OBJECTIVES 1.State the function of the Extraction Steam System. 2.Describe how Reactor Power will respond to the following: a.Loss of feed water heating b.Trip of a Heater Drain Pump 3.Describe why extraction steam stop valves and non-return check valves are used in extraction lines. 5

7. OBJECTIVES 4.Describe the function of the “Heater Drain Pumps” 5.Explain why water induction into the main turbine is undesirable. 6

8. Extraction Steam Purpose Provides steam to ALL 15 Feedwater heaters to heat the Condensate and Feedwater prior to entering the Steam Generators thus increasing plant efficiency. 7

9. 442°F 120°F 120ºF 184ºF 223ºF 288ºF 362ºF 401ºF 442ºF 8

10. 9

11. EXTRACTION STEAM LP HEATERS 1A, 2A, 3A TO CONDENSER LOW PRESSURE TURBINE CONDENSER A 3A 2A 1A 9 1211 M TO GLAND SEALING STEAM SYSTEM Rev 1 10

12. FEEDWATER HEATERS TYPICAL Of HEATERS 1, 2, 3, and 5 EXTRACTION STEAM INLET Condensate Flow Condensate Flow DRAIN INLET DRAIN OUTLET CONDENSATE INLET CONDENSATE OUTLET HIGH LEVEL DUMP Sub-cooled Zone Shell Side 6 5 4 HDT 3 2 1 CONDENSER 11

13. Extraction Steam Drain to 5 th Stage Feedwater Heater Drains Inlet 6 th Stage Feedwater Heater Feedwater Inlet Feedwater Outlet Subcooled Zone 12

14. HP/LP TURBINE MOV REPRESENTIVE OF ALL FEEDWATER HEATER EXTRACTION STEAM LINES FOR HEATERS 3, 4, 5, 6 Stop Valve EXTRACTION STEAM STOP VALVE Stop Check Valve STOP CHECK VALVE 3,4,5,6 13

15.  Extraction Steam Stop Valves and Non-return valves are used to protect the main turbine from:  Overspeed  Water entering turbine 14

16.  Water entering the main turbine is undesirable due to:  Erosion of the turbine blades  Vibration of turbine  Breakage of blades 15

17. COUNTER-WEIGHT TEST SWITCH CYLINDER AND PISTON EXTRACTION STEAM STOP CHECK VALVE 16

18. EXTRACTION STEAM STOP CHECK VALVE 17

19. FW HeaterStage of Extraction Steam Stop Valve Extraction Steam Non- Return Valve 1LP Turbine 12 th Stage NO 2LP Turbine 11 th Stage NO 3LP Turbine 9 th Stage YES 4HPT to MSR Cross Around Piping or 7 th stage YES 5HP Turbine 5 th Stage YES 6HP Turbine 3 rd Stage YES 18

20. LP TURBINE TT Stop Check Valve Stop Valve MOV 9 th 3 rd I LT I TT LT High-High 9 th Stage Extraction Steam From LP Turbine to 3 rd Heater 19

21. LP TURBINE Stop Check Valve Stop Valve MOV 7 th 4 th LT I TT Heater Drain Tank LT I Hi-Hi I LT High 7 th Stage Extraction Steam From HP Turbine to 4 th Heater (HP Turbine Exhaust Steam) 20

22. LP TURBINE TT Stop Check Valve Stop Valve MOV 9 th 3 RD I LSH High I LOW POINT DRAINS Drain Manifold Condenser Drain Manifold Condenser LSH DRAIN POT ORIFICE Drain Manifold Condenser I EXTRACTION STEAM LINE DRAIN VALVE LOCATION 21

23. LP TURBINE Stop Valve Stop Check Valve Drain Manifold Condenser LSH TT I DRAIN POT ORIFICE TT Drain Manifold Condenser Drain Manifold Condenser LOW POINT DRAINS MOV 9 th 3 RD I LSH I Steam Line Drain Valves: - Open on High HTR Level - Open on Turbine Trip - Open Stop Valve < 25% Open High Drain Pot Level Only opens Associative Drain Valve High Level TT < 25% Open 22

24. 23

25. Heater Drains The drainage from the various heat-exchanges (tube-side) after it transfers part of its heat energy to the Condensate & Feedwater flow stream is still at a relatively high energy so the water is pumped back into the Condensate & Feedwater System to also increase efficiency. 24

26. 25

27. Reheater Drain Tank (RHDT) The Normal Level Control Valve modulates controlling drain flow to the 6th stage heater based on Reheater Drain Tank Level. If the level in the Reheater Drain Tank reaches the high level setpoint it will cause the “high level dump” valve to modulate open to dump the contents of the Reheater Drain Tank to the associated 4th stage heater. 26

28. Moisture Separator Drain Tank (MSDT) The Normal Level Control Valve modulates controlling drain flow to the Heater Drain Tank based on the MSDT level. If the level in the MSDT reaches the high level setpoint it will cause the High Level Dump Valve to modulate open to dump the contents of the “MSDT” to the Condenser. 27

29. Moisture Separator Reheater Rising level will cause a Main Turbine Trip on HIGH Level (2/3 Level Switches) on 1/4 Moisture Separator Reheaters. 28

30. 6A LT C LT B LT A LV4288 FO LV4284 FO Feedwater Heater 5A LT A LT B I/P LT C Main Condenser “A” I/P RHDT normal drain Valves into 6A (C) Scavenging Steam will align to Main Condenser Extraction Steam: Isolation Valve (C) Non-Return Valve (C) Drain Valves (O) 29

31. 5A LT C LT B LT A LV4282 FO LV4286 FO Feedwater Heater 4A LT A I/P LT B I/P Main Condenser “B” LT C Normal drain from 6A (C) Extraction Steam: Isolation Valve (C) Non-Return Valve (C) Drain Valves (C) 30

32. 4A LT C LT B LT A LV4331 FC LV4333 FO HDT “A” LT A LT C I/P LT B I/P LT C Normal drain valve from 5A (C) MSDR normal drain valves (C) Extraction Steam: Isolation Valve Non-Return Valve Drain Valves Main Condenser “A” Between 4A and 5A Feedwater Heater 31

33. HDT “A” 4A LT C LT B LT A Between 4A and 5A Feedwater Heater LV4331 FC LV4333 FO LT A LT C I/P LT B I/P LT C Extraction Steam: Isolation Valve Non-Return Valve Drain Valves Main Condenser “A” 32

34. 33

35. Heater Drain Pumps Why do we need the Heater Drain Pumps? During normal operation, the heater drain tank pump provides 1/3 of the flow requirements for NPSH to the main feedwater pumps and assists in preheating feedwater. 34

36. 35

37. How would Reactor Power respond to the trip of a Heater Drain Pump with the Reactor at 100% power ? A. Stay the same. B. Increase. C. Decrease. 36 √

38. Heater Drain System Malfunction Malfunction of feedwater heater drain system could have a significant impact on plant operation. Plant efficiency would be reduced because Loss of feedwater heating capability May exceed reactor core limits: – Reactor Power – RCS Delta Temperature Limits – RCS Pressure limits 37

39. SUMMARYSUMMARY Extraction Steam, Feedwater Heaters and Heater Drain systems are important to the preheating of feedwater prior to flowing into steam generator and for improving secondary efficiency. A loss of any feedwater heating causes reactor power to increase due to the decrease in RCS temperature. Not maintaining proper feedwater heater level also causes a decrease in secondary efficiency which affects reactor power. 38

40. Objectives Review 1.State the function of the Extraction Steam System. 2.Describe how Reactor Power will respond to the following: a.Loss of feed water heating b.Trip of a Heater Drain Pump 3.Describe why extraction steam stop valves and non-return check valves are used in extraction lines. 39

41. Objectives Review 4.Describe the function of the “Heater Drain Pumps” 5.Explain why water induction into the main turbine is undesirable. 40