1. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. 核能發電原理與安全提升 Principles of Nuclear Power and Safety Enhancement after Fukushima Accident Chin Pan Department of Engineering and System Science National Tsing Hua University Hsinchu, Taiwan, ROC Presented at Department of Mechanical Engineering National Cheng Kung University March 26, 2015 13:00 ~ 15:00

2. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. OUTLINE Introduction Nuclear Power in the World Principles of Nuclear Power Philosophy of Nuclear Safety Design Operation and Safety Performance of Nuclear Power Plants in Taiwan Safety Re-evaluation and Enhancement after Fukushima Accident Fourth Generation Nuclear Power Plants Conclusions

3. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Background Concentration of CO 2 has been increased by 16% over the past half century mainly due to the burning of fossil fuels From: Fuel Cells, Green Power, U.S. Department of Energy, Energy Efficiency and Renewable Energy From:F.S. Hsu, 2005, “The Energy Problem at a Glance ”

4. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Global Warming and Climate Change? From: Fuel Cells, Green Power, U.S. Department of Energy, Energy Efficiency and Renewable Energy

5. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Countermeasures: Renewables and Nuclear Power

6. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Renewables and Nuclear Power Produce Much Less CO 2

7. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. From: Mujid S. Kazimi, “Nuclear Power Innovations For Enhanced Economy and Safety”, Presented at NTHU, Dec, 8, 2004

8. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. IEA BLUE-MAP scenario Reducing CO2 emission in 2050 (57Gt) to a half of 2005 emission (14Gt) CCS:20%; renewables:16%; Nuclear Power: 6%; power generation efficiency and fuel switching:5%; end use fuel switching:15%; end- use fuel and electricity efficiency:38% Nuclear power increased from current generation (370 GWe; 14%) to 1250 GWe (24%) in 2050, approximately three times of current generation Constructing 20 units each year in 2020’s to 20-30 units in 2040’s

9. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Fukushima Accident On March 11, 201, an over DBA tsunami after a Richter scale 9 earthquake leading to a severe accident Many lessons learned from the accident Nuclear power becomes safer through safety enhancement after Fukushima accident Public concerns on nuclear safety and anti-nuclear movement in Taiwan

10. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. OUTLINE Introduction Nuclear Power in the World Principles of Nuclear Power Philosophy of Nuclear Safety Design Operation and Safety Performance of Nuclear Power Plants in Taiwan Safety Re-evaluation and Enhancement after Fukushima Accident Fourth Generation Nuclear Power Plants Conclusions

11. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. 加拿大 19 部機組運行中 (13.5 GW) 美國 100 部機組運轉中 (99.08GW) 5 部新機組在建 (5.63GW) 全球 437部機組運行中 (374.5 GWe) 72部機組在建中 (69.13 GWe) 印度 21 部機組運行中 (5.31 GWe) 6 部機組在建中 (3.91 GWe) 2030 核能佔比 →>25% 中國 22 部機組運行中 (18.06GWe) 27 部機組在建中 (26.76 GWe) 2020→70-80 GWe 歐洲 184 部機組在運行中 (161.74 GWe) 18 部新機組在建 (16.61 GWe) 南韓 23 部機組運行中 (20.72 GWe) 5 部機組在建中 (6.37 GWe) 2035 核能佔比 →60% 日本 48 部機組停機中 (42.39 GW) 2 部機組在建中 (1.33 GW) IAEA 預測到 2030 年 全球至少增加 90 部機組 至多增加 300 餘部機組 Nuclear Power in the world 資料來源： IAEA PRIS 2014 年 10 月 12 日

12. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Nuclear Power Policy and Development in Taiwan 6 units in operation (4 BWRs + 2 PWRs) Providing about 18% of electricity (8% of energy) Construction of the 4 th nuclear power plant) suspended (a referendum will be conducted to decide whether or not the construction will be continued)

13. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. OUTLINE Introduction Nuclear Power in the World Principles of Nuclear Power Philosophy of Nuclear Safety Design Operation and Safety Performance of Nuclear Power Plants in Taiwan Safety Re-evaluation and Enhancement after Fukushima Accident Fourth Generation Nuclear Power Plants Conclusions

14. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Principles of Nuclear Power

15. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Atomic and Nuclear Structure From ： R.L. Murray, Nuclear Energy-An Introduction to the Concepts, Systems and Applications of Nuclear Process, 2 nd Ed., Pergamon Press, 1980 For 92 U 235 : 92 protons & 143 neutrons Size of the nucleus: 10 -15 m

16. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Binding Energy per Nucleon as a Function of Atomic Mass Number From: J. R. Lamarsh, Introduction to Nuclear Engineering For example: the binding energy per unit nucleon for 92 U 235 can be calculated as: (92×1.00797 +143×1.00867- 235.0439)amu ×931Mev/amu÷235=7.64 Mev

17. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. H-2 H-3 Neutron 14.1MeV He-4 3.5MeV A fusion reaction From: C. K. Shih

18. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Neutron U-235 U-236 分裂 Fission fragments Fission fragment neutron γ ray U-236 分裂 Fission of U-236 A fission reaction From: C. K. Shih

19. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. An Example of Fission Reaction of U- 235 235.0439 1.00867 136.9061 96.9212 2×1.00867 mass defect

20. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. E = M C 2 Energy corresponding to 1 amu Energy corresponding to the mass defect of a fission reaction of U-235 =0.20793 amu × 931 Mev/amu =200 Mev The energy released by fission reactions is six order of common chemical reactions such as combustion of fossil fuels Photograph from www.xtec.es

21. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Chain Reaction

22. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Fuel Consumed Every Day for a 3000MW t Power Plant FuelFuel consumed (kg/day) U-2353.9 Coal8.1×10 6 Oil5.9×10 6 Natural Gas5.2×10 6

23. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Annual Fuel Transportations Needed for the 4th Nuclear Power Plant in Taiwan (1300 MWe × 2) 1.78 × 10 10 kW-h Nuclear 81 tons Natural gas 2,600,000 tons Oil 4,340,000 tons Coal 6,510,000 tons From: Taiwan Power Company

24. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Conversion and Breeding Conversion of 92 U 238 into 94 Pu 239 Conversion of 90 Th 232 into 92 U 233 IsotopeAbundance(%) U 234 0.0057 U 235 0.72 U 238 99.27 Breeding: if more fissile materials are produced than consumed

25. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Uranium resources in the world Known uranium resources Total uranium reserve based on traditional mining technology Including non- traditional mining technology uranium resources Current reactor technology 100 y300 y700 y Closed fuel cycle and FBR technology 〉 3,000 y 〉 9,000 y 〉 21,000 y From ： Nuclear Energy Outlook, OEC Nuclear Energy Agency, 2008

26. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Fuel Pellets, Fuel Rods, Fuel Assembly and Reactor From: Nuclear Power in an Age of Uncertainty From: J. R. Lamarsh, Introduction to Nuclear Engineering

27. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. From: C. K. Shih

28. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Schematic of a Boiling Water Reactor From: Nuclear Power in an Age of Uncertainty

29. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. OUTLINE Introduction Nuclear Power in the World Principles of Nuclear Power Philosophy of Nuclear Safety Design Operation and Safety Performance of Nuclear Power Plants in Taiwan Safety Re-evaluation and Enhancement after Fukushima Accident Fourth Generation Nuclear Power Plants Conclusions

30. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Philosophy of Nuclear Safety Design Multiple barriers for radiation Defense in depth

31. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Multiple Barriers for Radiation Fuel pellet cladding Reactor vessel Steel Containment Reinforced concrete containment

32. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Nuclear Safety Site selection, Good design, construction And operation following the procedure with care Protection and safety systems Additional Safety system for Accident mitigation Defense in Depth

33. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Residue Heat after Reactor Shut Down After one year of full power operation Time after shut down 1sec1mi n 1hr1d30d90d1 year Percentage of rated power(%) 6.23.71.50.610.140.0730.024 Such residue heat must be removed in time, otherwise, The fuel rods in the core may be melt

34. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Emergency Core Cooling Systems in a Mark-III containment with BWR-6 From: R. T. Lahey & F. J. Moody, The Thermal Hydraulics of Boiling Water Nuclear Reactor The core melt frequency for present nuclear power plants is in the order of 10 -5 /yr

35. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. 施純寬教授提供

36. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Spent fuel pool ： Containment: MARK-I ； unit 2 might be damaged suppression pool Reactor building Unit 1,3,4 destroyed due to hydrogen explosion Reactor: unit 1, 2, 3, core uncover ； hydrogen generation due to zirconium- steam reaction; core melt Loss of off-site power Diesel generator destroyed due to tsunami flood Fukushima Daiichi Accident

37. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. OUTLINE Introduction Nuclear Power in the World Principles of Nuclear Power Philosophy of Nuclear Safety Design Operation and Safety Performance of Nuclear Power Plants in Taiwan Safety Re-evaluation and Enhancement after Fukushima Accident Fourth Generation Nuclear Power Plants Conclusions

38. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Status of nuclear power units in Taiwan a: MUR for 1-2% completed in July 2009 and planned for SPR (3%); b: possible date for commercial operation Nuclear Power Plant unit Rated Power (MWe) Commercial operation date License Due Space Available for more units Chinshan (BWR-4) 1636 a 1978.12.062018.12.05 1-2 2636 a 1979.07.162019.07.15 Kuosheng (BWR-6) 1985 a 1981.12.282021.12.27 2 2985 a 1983.03.152023.03.14 Ma’anshan (PWR) 1951 a 1984.07.272024.07.26 4 2951 a 1985.05.182025.05.17 Lungmen (ABWR) 11,3502015.12.15 b 2051.12.15 4 21,3502016.12.15 b 2052.12.15

39. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. 39 Total NO. of Scram Total No. of Abnormal Events Data provided by TPC Maanshan power plant Kaosheng power plant Chinshen power plant Abnormal events and Scrams Decreased exponentially

40. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. 40 Capacity factor increased and cost reduced significantly Data provided by TPC From: NEI, 2009.08

41. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. 41 Volume of low-level solid radioactive waste reduced exponentially using domestic technology Using the technology developed by INER, the number of barrels of solid low-level waste has been reduced exponentially.

42. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. OUTLINE Introduction Nuclear Power in the World Principles of Nuclear Power Philosophy of Nuclear Safety Design Operation and Safety Performance of Nuclear Power Plants in Taiwan Safety Re-evaluation and Enhancement after Fukushima Accident Fourth Generation Nuclear Power Plants Conclusions

43. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Assurance of Nuclear Safety AEC– Completed 1st and 2nd phases Nuclear Safety Reassessment Programs -- Revealing neither immediate nuclear safety concern nor threat to the public health and safety -- Requiring TPC to enhance capability of each power plant, including both plants in operation or under construction, to cope with extreme natural disasters, including earthquakes, tsunamis, extreme rainfalls and mudslides and take possible countermeasures -- The program comprised of two parts: (1) Nuclear safety assurance; (2) radiation protection and emergency response preparedness

44. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Nuclear Safety Assurance Mitigation to a Prolonged Station Blackout Protection Against Tsunami Hazards Spent fuel Cooling Hydrogen Detection and Explosion Prevention Severe Accident Management Protection Against Seismic Hazards Infrastructure Resilience Safety Culture

45. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Standby Power at NPPs of Taiwan Standby Power Fukushim a ChinshanKuoshenMa’ashanLungmen Emergency Diesel generator （ EDG ） 2 unit/reactor EL 12M 3unit/react or EL 12M 2unit/react or EL 15M 3unit/reactor EL 12M additional EDG to be shared （ gas-cooled ） none 1 unit EL 12M 1 unit EL 12M 1 unit EL 15M 1 unit EL 12M Gas turbine generator none 2 unit/2 reactor EL 22M 2 unit/2 reactor EL 22M 2 unit/2 reactor EL 35M 2unit/2reactor EL 29.8M (plan to construct) From:TPC Adding several mobile power after safety re-assessment

46. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Elevation of NPP sites in Taiwan SiteChinshanKuoshengMa’anshanLunmen Elevation （ m ） 12 1512 Possible height of tsunami （ m ） 10.7310.28118.07 From:TPC AEC requires TPC to construct tsunami wall of 6 m

47. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Radiation Protection and Emergency Response Preparedness -Reassessment of -- (Relevant laws, regulations and implementation) -- Emergency planning and preparedness -- the implementing capabilities of emergency response -Expanding the Emergency Planning Zone from 5 km to 8 km -Establishment of a mechanism to respond to compound disasters. -Establishment of the capability for assessing dose resulted from overseas nuclear accidents. -Enhancement of domestic capability of radiation fallout monitoring in a timely manner.

48. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. TPC’s Actions to Ensure Nuclear Safety Following the requirement of AEC and international safety standards to enhance safety Re-Assessment of nuclear safety comprehensively for each power plant Enhancement of preparedness and capability to cope with compound disasters Completed the decennial integrated safety evaluation in advance for each plant Carried out a stress test for each plant based on the European standards Establishment of Ultimate Response Guideline for each plant

49. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. NPPs in Taiwan is Much Safer Than Ever With the lessons learned from the Fukushima accident Actions implemented following the safety re-assessment Ultimate Response Guideline: giving up the plant and preventing the large release of radiation outside the plant

50. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab.  To counteract with beyond design basis accidents, TPC proposed the Ultimate Response Guideline  Employing the limited human resources to line up standby water resources, (including standby raw water, water from creek nearby, and even sea water), emergency depressurization, and containment venting in the shortest time  If needed, injecting the water available into reactor or spent fuel pool to prevent zirconium-steam reaction, which may produce hydrogen  To prevent large release of radiation from NPP  URG has been reviewed by BWROG with positive comments Ultimate Response Guideline (URG)

51. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. 51 Standby Water Resources SiteSea water Raw water pool total water needed to fill the containment up to the top of fuel rods (ton/reactor ) Inventory (ton)Lowest elevation (m) Chinshan all installed emergency recirculation water system 106,000629,000 Kuosheng 36,8399010,600 Ma’ashan 109,500513,700 Lungmen 48,0001164,110 Note ： The seismic design for the raw water pool will also be enhanced From: TPC

52. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Action timing of URG 資料來源 : 台灣電力公司 Action order: deputy general manager of nuclear power of TPC or manager on duty in the site Action timing, any of the following three conditions applicable: 1. loss of water makeup capability to maintain the coverage of nuclear fuels in the core 2. Loss of offsite and in-site AC powers 3. Reactor scram due to strong earthquake and warning of tsunami from the Central Weather Bureau

53. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. OUTLINE Introduction Nuclear Power in the World Principles of Nuclear Power Philosophy of Nuclear Safety Design Operation and Safety Performance of Nuclear Power Plants in Taiwan Safety Re-evaluation and Enhancement after Fukushima Accident Fourth Generation Nuclear Power Plants Conclusions

54. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Generation IV Nuclear Energy System Development Project Generation IV International Forum (GIF), 2005/2/28, including Canada, France, Japan, UK and USA Further advances in nuclear energy system design to broaden the opportunities for the use of nuclear energy From:Y. Sagayama, Proc.Global 2005

55. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. GOALS FOR GENERATION IV Sustainbility-1:clean air; long-term availability of systems; effective fuel utilization Sustainbility-2: minimize and manage their nuclear waste and notably reduce the long-term stewardship burden; thereby improving protection for the public health and the environment Proliferation resistance and physical protection: increase the assurance that they are a very unattractive and the least desirable route for diversion or theft of weapons-usable materials, and provide increased physical protection against acts of terrorism.

56. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. GOALS FOR GENERATION IV (cont’d) Economics: have a clear life-cycle cost advantage over other energy sources; Economics-2: have a level of financial risk comparable to other energy projects Safety and reliability-1: excel in safety and reliability Safety and reliability-2: have a very low likelihood and degree of reactor core damage Safety and reliability-3: eliminate the need for offsite emergency response

57. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Six Candidate Nuclear Energy Systems Very-high-temperature gas-cooled reactor Sodium-cooled fast breeder reactor Supercritical-water-cooled reactor Lead-cooled fast breeder reactor Gas-cooled fast breeder reactor Molten salt (breeder) reactor

58. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Spent Fuel Management From: Mujid S. Kazimi, “Nuclear Power Innovations For Enhanced Economy and Safety”, Presented at NTHU, Dec, 8, 2004

59. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. OUTLINE Introduction Nuclear Power in the World Principles of Nuclear Power Philosophy of Nuclear Safety Design Operation and Safety Performance of Nuclear Power Plants in Taiwan Safety Re-evaluation and Enhancement after Fukushima Accident Fourth Generation Nuclear Power Plants Conclusions

60. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. Conclusions The safety and operation performance have been excellent for nuclear power plants in Taiwan Lessons learned from Fukushima accidents make the nuclear power plants in the world much safer than ever now Nuclear power can be and has been developing toward a sustainable energy source: inherently very low CO 2 emission; waste minimization and maximum use of uranium resources; proliferation resistant; co-generation of hydrogen. Nuclear power will still play an important role for current and future energy need around the world.

61. Engineering & System Science Boiling Heat Transfer and Multi-Phase Flow Lab. TPC’s Actions to Ensure Nuclear Safety (cont’d) Newly constructed nuclear power plant, i.e., Lungmen NPP, must be assessed by World Association of Nuclear Operators (WANO) Nuclear safety experts from international institutions will be invited to assist our Atomic Energy Council to carry out the survey and inspection for Lungmen NPP.