Role of Advanced Nuclear Power In Environment Sustainability

Transcription

1 Role of Advanced Nuclear Power In Environment Sustainability Ruchi Gakhar, UW Madison Earth Day Conference UW Madison 25 April 2016 UCB Thermal Hydraulics Lab

2 Energy Sources Nuclear Plants United States World Share in Energy Mix 19.47% 16% Current Capacity GWe 353 GWe Capacity Under Construction 5.6 GWe 40 GWe World Nuclear Association, US NRC Nov

3 Mitigation of Greenhouse Gas Emissions Energy Portfolio Wedges: Nuclear: 700 new gigawatt-sized plants (plus replacement plants) Even with a very conservative goal, we ll need all the low-ghg technologies available. US DOE and Generation IV International Forum. A Technology Roadmap for Generation IV Nuclear Energy Systems. Dec accessed12/10/2008 3

4 Energy Density 4

5 How Deadly is Your Kilowatt? Forbes Magazine, Energy, 6/10/2012 Fatalaties per TWhr Coal - China 280,000 Coal - global average 170,000 Oil 36,000 Biofuel/Biomass 24,000 Coal - US 15,000 Natural gas 4,000 Hydro 1,400 Solar (rooftop) 440 Wind 150 Nuclear 90 US 2012: 3.8 TWhr consumption Coal mine worker, China,

6 Radiation Exposure in the U.S. 6

7 Nuclear Fuel Cycle (1) Lindberg, Max. Navajos On Warpath Over Uranium Mining On Tribal Lands. Planetsave. 19 Apr (2) Saleeite. Australian Minerals Page. 7

8 Five Main Steps for Nuclear Fuel Production extraction of natural ore I. Mining II. Milling extraction of uranium from the ore conversion from U 3 O 8 to UF 6 III. Yellow cake IV. Enrichment natural enrichment (0.7 % 235 U) 3.3 % 235 U for PWR Pictures from 8

9 Five Main Steps for Nuclear Fuel Production V. Fuel Fabrication conversion from UF 6 to UO 2 Pictures from 9

10 Power Plant Design and Construction Figure Titles: 4-D Computer-Aided Design and Virtual Walk-Through, 1000 MW PWR Reactor, Lianyungang Unit 1, and PB-AHTR Reactor Concept. Per Peterson. PB-AHTR Review and Thermal Hydraulics Test Program. Meeting on Risk Informed, Technology Neutral Licensing. Berkeley, California. July 21,

11 Most nuclear plants today are Pressurized Water Reactors 11

12 Low-level waste, LLW 97 % by volume High-level waste, HLW 3% Spent Fuel Reprocessing of Spent Fuel To convert HLW to LLW To obtain Recycled fuel, Ex Mixed Oxide Fuel MOX (Pu-U- O 2 ) fuel Today MOX is widely used in Europe (about 40 reactors) and in Japan (about 10 reactors). 12

13 Spent Fuel Storage (1) (2) (3) 13

14 Present Challenges faced by Nuclear Plants Spent Fuel Storage Passive Safety Fuel Meltdown High heat removal capacity Pressure of containment Costs 14

15 Nuclear Reactors Technology Roadmap Image Source: 15

16 + = Passive Safety Use of natural circulation loops No loss of coolant = no meltdown Gen III+ Reactors Westinghouse AP1000 NuScale Small Modular Reactor In US, 2 plants (4 units ) are under construction Georgia and South Carolina 1000 MWe each Dimensions 76' x 15' cylindrical containment vessel module containing reactor and steam generator Electrical capacity 50 MWe (gross) Image Sources : Westinghouse AP 1000 Station Blackout Scenario, 16

17 Gen IV Reactors Features Highly economical, enhanced safety and minimal waste Advanced reactor designs - Sodium-Cooled Fast Reactor (SFR), Supercritical Water Reactor (SCWR), Gas Cooled Reactors - X-energy (Xe-100), Molten Salt Reactors ORNL MSR, Pebble Bed MSR, Integral MSR, Molten Chloride Fast Reactor X-energy (Xe-100) Sodium-Cooled Fast Reactor (SFR) 17

18 Molten Salt Reactor 18

19 Research and Development at the Department of at UW-Madison Advanced Nuclear Materials Reactor Safety Thermal Hydraulics Corrosion studies Students are given practical experience with the 10 MW research reactor on campus. Collaborations with Industry, National Laboratories, Government and efforts to reach out to the public Molten Salt Reactor Design Dr. Kumar Sridharan, Dr. Mark Anderson and Dr. Raluca Scarlat 19

20 Fluoride salt cooled High Temperature Reactor (FHR) Coated particle fuel (TRISO Fuel) FHRs have uniquely large fuel thermal margin Liquid fluoride salt coolants FLiBe (2LiF-BeF 2 ) Boiling point ~1400ºC Excellent heat transfer Transparent, clean fluoride salt Reacts very slowly in air No energy source to pressurize containment 20

21 PB-FHR Design Current physical plant arrangement 21

22 Passive Safety feature The bottom of each cold-leg stand pipe has a freeze valve with a line extending to a maintenance drain tank. In case excessive temperatures are reached, the primary salt will be drained by gravity into dump tanks configured to prevent criticality. 22

23 Advanced Reactors: An Outburst of Innovation Significant recent interest in advanced reactors: White House Meetings Institutes» Third Way Institute» Breakthrough Institute» GAIN $1.3 Billion in private investment Nuclear Energy Innovation and Modernization Act Nuclear Innovation Alliance: Strategies for Advanced Reactor Licensing 23

24 Nuclear Innovation Bootcamp August 1-12, 2016 at UC Berkeley Learn how to innovate: Entrepreneurship Nuclear aspects Non-traditional course material Design your own innovative solutions Address a problem of your choice Teams include technical & non-technical members Present your ideas to key industry stakeholders Network with mentors from nuclear companies, professors from other universities, scientists in national labs, professionals from industry Applications due by the end of this month 24

25 Thank You! Ruchi Gakhar Post Doctoral Research Associate Department of Engineering Physics University of Wisconsin Madison rgakhar@wisc.edu Phone :