The Nuclear Fuel Cycle Name Affiliation Title Navigating

The Nuclear Fuel Cycle Name Affiliation Title Navigating Nuclear Science

2 Nuclear fuel • What is it? • Where does it come from? • How is it used? Nuclear fuel pellets are stacked vertically in long metal tubes to power commercial nuclear reactors. Photo courtesy of Orano USA (Areva) and the NRC. Navigating Nuclear Science

3 It starts with U Navigating Nuclear Science

4 Uranium mining—open pit Navigating Nuclear Science

5 Uranium mining—in situ Navigating Nuclear Science

6 Uranium milling 1. Ore is crushed 2. Uranium is separated 3. U 3 O 8 “yellow cake” produced Navigating Nuclear Science

Step 2 Navigating Nuclear Science

8 Uranium conversion to UF 6 gas 1. Impurities removed 2. Uranium combined with fluorine 3. UF 6 gas produced Navigating Nuclear Science

Step 3 Navigating Nuclear Science

10 U enrichment UF 6 enriched from 0. 7% 235 U to 3%-5% 235 U Diffusion Centrifugation Navigating Nuclear Science

Step 4 Navigating Nuclear Science

Fuel fabrication Uranium oxide ceramic fuel pellets Navigating Nuclear Science

Fuel rods filled with pellets grouped into fuel assemblies Navigating Nuclear Science

14 Fuel fabrication A pressurized water reactor fuel assembly Navigating Nuclear Science

Step 5 Navigating Nuclear Science

16 Inside the reactor Cherenkov radiation glowing in the core of the INL Advanced Test Reactor. Navigating Nuclear Science

17 In the reactor, 235 U fissions to produce. . . Neutron Lighter element Energy Uranium-235 Neutron Energy Neutron Lighter element Neutrons may • Cause new fissions to occur • Be absorbed to form unstable, radioactive nuclide Navigating Nuclear Science

18 Fuel consumption in the reactor • Fuel is in reactor for 4 – 6 years • Uranium consumed • Fission products and transuranics produced Fresh Fuel 100% uranium dioxide (UO 2) 4% Fission Products 95% uranium dioxide (UO 2) Used Fuel 1% Transuranics Navigating Nuclear Science

19 So what and where is the waste? Navigating Nuclear Science

20 Types of radioactive waste Radioactive Waste in the United States Low Level Waste High Level Waste Transuranic Waste Navigating Nuclear Science

21 Low-level waste Navigating Nuclear Science

22 Low-level waste disposal Navigating Nuclear Science

23 Low-level waste disposal sites Four low-level waste disposal facilities: • Richland, WA • Clive, UT • Barnwell, SC • Andrews, TX Navigating Nuclear Science

24 Transuranic waste Navigating Nuclear Science

25 Navigating Nuclear Science

26 High-level “waste” Dry cask storage Navigating Nuclear Science

27 Waste packaging Navigating Nuclear Science

Step 6 Navigating Nuclear Science

29 Used nuclear fuel storage Used fuel first stored in pool at least 5 years • Cooling and shielding Older fuel can move to dry casks • Steel and concrete shields • Air cools Navigating Nuclear Science

30 Step 9 Navigating Nuclear Science

31 Geologic repository • The choice of countries worldwide • U. S. has studied Yucca Mt. Navigating Nuclear Science

32 Yucca Mountain Navigating Nuclear Science

Step 7 Navigating Nuclear Science

34 Fuel consumption in the reactor Fresh Fuel 100% uranium dioxide (UO 2) 4% Fission Products 95% uranium dioxide (UO 2) Used Fuel 1% Transuranics Navigating Nuclear Science

35 Reprocessing World Nuclear Association Navigating Nuclear Science

36 Research Electroplated uranium from pyroprocessing Sodium cooled fast reactor Navigating Nuclear Science

Step 8 Navigating Nuclear Science

38 Recycling nuclear fuel • Continuously recycling fuel can reduce spent fuel waste volume by over 95% • Reduces isolation time from 1000 s of years to 100 s • Remaining waste is placed in robust containers designed for safety and shielding Navigating Nuclear Science

39 Why not here in the U. S. ? Navigating Nuclear Science

40 Questions? Navigating Nuclear Science