Module 05 WWER/ VVER (Russian designed Pressurized Water Reactors)

Transcription

1 Module 05 WWER/ VVER (Russian designed Pressurized Water Reactors) Prof.Dr. Böck Technical University Vienna Atominstitut Stadionallee 2, 1020 Vienna, Austria ph:

2 VVER= Voda-Vodyanoi Energetichesky Reaktor= Water Cooled Power Reactor VVER 440/230 VVER 440/213 VVER 1000/320 VVER 1200

3 VVER Reactor Sites

4 VVER Reactors near the Austrian Border

5 Russian designed VVER NPPs

6 VVER Generations

7 VVER

8 Common Features of VVERs GEN 1+2 (1) Hexagonal fuel assembly cassettes Horizontal steam generator Primary circuit and secondary circuit using different materials Reduced inspection, reproducible possibilities of components Little documentation (440/230) Lack of independent control and regulatory supervision Quality lack in instrumentation, control and data processing No reproducible safety analysis

9 Common Features of VVERs GEN 1+2 (2)

10 Technical Aspects of VVERs for 1st Generation VVERs are the workhorses of former Sovietunion Simple, cheap and robust constructions Rely more on overdimension than on sophisticated computer codes Little automatisation, human reliability is higher than the reliability of I&C systems Accident prevented with choice of material and material dimension

11 VVER 440 Flow Diagram A - Primary circuit coolant water B1 - Steam from SG B2 - Feed water C - Cooling water 1. Reactor 2. Steam generator 3. Main circulation pump 4. Main isolation valve 5. Pressurizer 6. Pressurizer quench tank 7. Electrical heaters 8. Pressurizer spray 9. Core 10.Fuel assembly 11.Control rod drives 12.Control rod absorber part 13.Control rod fuel follower 14. Medium-pressure turbine part 15. Low-pressure turbine part 16. Generator 17. Transformer 18. Moisture separator - re-heater 19. Main condenser 20.Condensator pump 1. part 21.Condensate chem. treatment unit 22.Condensator pump 2. part 23.Low-pressure preheaters 24.Main feedwater tank 25.Main feedwater pump 26.High-pressure preheaters 27.Cooling tower 28.Cooling water pump

12 VVER Primary Circuit

13 Reactor Pressure Vessel 1 reactor pressure vessel, 2 vessel closure head, 3 free flange, 4 - core barrel, 5 core barrel bottom, 6 reactor core, 7 guide tubes 8 guide tubes upper part 9 protection tubes with dumpers, 10 control rod drives, 11 inlet nozzle, 12 outlet nozzle

14 VVER Fuel Assembly

15 Fuel Element seen from Top

16 Refuelling VVER New Fuel

17 VVER Steam Generator Structure of the steam generators in VVER-440 units 1 - steam generator body, 2 - primary cold leg collector, 3 - primary hot leg collector, 4 - manhole, 5 - heat exchanger tubes, 6 - vertical distance grid, 7- horizontal distance grid, 8 - feedwater pipeline, 9 - separator, 10 - perforated sheet, 11 - steam header, 12 - primary circuit header cover, 13 - secondary circuit header cover, 14 cover seals for the primary and secondary circuit, 15 - secondary circuit seal cover monitoring location, 16 secondary circuit air vent, 17 - primary circuit seal cover monitoring location, 18 - primary circuit air vent, 9 - header periodic blowdown, 20 - steam generator periodic blowdown, 21 - steam generator permanent blowdown, 22 - nozzle, 23 - pipe unions for steam generator level checking.

18 VVER Steam Generator

19 WWER 440/230

20 VVER 440/230 Safety Aspects Six primary loops Motor driven valves in all six loops Fuel follower control rods Two NPP on one site Common turbine generator hall for both NPPs Rooms designed to withstand higher pressure instead of full pressure containment No full capacity emergency core cooling system in case of main coolant pipe rupture Accelerated material embrittlement due to fast neutron irradiation of pressure vessel

21 VVER 440/213 Legend: 1.Reactor pressure vessel, 2.Steam generator, 3.Refueling machine, 4.Spent fuel pit, 5.Confinement system, 6.Make-up feedwater system, 7.Protective cover, 8.Confinement system, 9.Sparging system, 10.Check vales, 11.Intake air unit, 12.Turbine, 13.Condenser, 14.Turbine block, 15. Feedwater tank with degasifier, 16. Preheater, 17.Turbine hall crane, 18.Electrical instrumentation and control compartments.

22 Basic VVER 440/213 Technical Data Thermal power: 1375 MW th Electrical power: 440 MW e Primary pressure: MPa Primary temperature: 267 ºC -297 ºC Coolant flow: m 3 /h Core height: 2.50 m Core diameter: 2.88 m Enrichment: 1.6 to 3.6 % U-235 Total fuel load: 42 t Number of fuel assemblies: 312 Rods per assembly: 126 Number of control rods: 37 Type: Hexagonal fuel follower rods, borated steel

23 VVER 440/213 Safety Aspects Many safety deficits of VVER 440/230 removed Pressure suppression system through bubble condensor Emergency core cooling system designed for maximum LOCA Safety systems in 3 x 100% redundancy, separated from operational I&C system Improved fire protection Separated emergency control room Reduction of neutron fluence to pressure vessel wall Surveillance system of safety relevant primary components For Mochovce 3&4 only Digital I&C system External pressure vessel cooling in case of core melt Containment spray system for heat removal by sump water recirculation Control of hydrogen concentration

24 View on Pressure Vessel Top and Pits for Primary Pumps

25 Refuelling Machine

26 CASTOR Inside (left) CASTOR loaded (right)

27

28 VVER 1000/320 Safety Aspects Full pressure containment designed 0.5 MPa Emergency cooling system designed for whole spectrum of LOCA Improved materials for primary and secondary components Improved access for reinspection and maintenance Low leakage core loading to reduce neutron fluence to pressure vessel wall For Temelin only: Replacement of total I & C system, by Westinghouse Fuel elements produced by Westinghouse

29 NPP Dukovany Czech Republic VVER 440/213 4 Reactors 4 x 440 MWe

30 Interim Spent Fuel Storage at Dukovany NPP

31 Kernenergie und CO2

32 NPP Mochowce Slovak Republic VVER 440/213 2 Reactors 2 x 440 MWe

33 NPP Temelin Czech Republic VVER 1000/320 2 Reactors 2 x 981 MWe

34 Status of WWER Nuclear Power Plants around Austria ATW 2015, p.504, Some years ago CZ announces to built two more 1000 MWe NPPs at the Temelin site Temelin1+2 has been upgraded from 960 MWe to 1080 MWe The 4 Dukovany plants will reach their end of lifetime by 2035 and have to be replaced gradually Therefore plans are to keep all options open, decision will be made by 2025 where and how many new NPPs will be constructed Mochovce 3 & 4 should be operational in 2017, plans exist for another WWER 1200 NPP at the Bohunice site by 2025 Paks 4 NPPs received 20 years life time extension, contracts have been signed with Rosatom for 2 WWER 1200 MWe NPPs to be operational 2023 and 2025.

35 VVER 1200 General Lay out

36 VVER-1200 Technical Data

37 VVER 1200 Pressure vessel, primary system

38 VVER-1200 Core, Fuel Assembly

39 What you should remember H 2 O as coolant and moderator Typical PWR parameters, slightly lower primary pressure VVER are of simple and robust construction First generation has safety deficits which have been eliminated at the second generation Third generation VVER 1000 comparable to Western PWRs 4 VVER 440/213 in Dukovany, 2 VVER 1000 in Temelin, 4 VVER 440/213 in Paks, 2 VVER 440/213 in Mochovce, 2 VVER 440/213 in Bohunice About VVER 1200 in various stages of construction

40 References Info about VVER Reactors: c36958cfface920d36ab1/brochure_the_v ver_today.pdf