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Nuclear Waste Disposal: A Global Challenge

Learn about nuclear waste disposal strategies, including reprocessing and direct disposal, vitrification into glass, storage techniques, transportation safety, and global nuclear waste statistics.

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Nuclear Waste Disposal: A Global Challenge

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  1. The environment is everything that isn’t me. Albert Einstein

  2. NUCLEAR WASTES

  3. ONE OF THE BIGGEST ARGUMENTS AGAINST NUCLEAR POWER IS THE GENERATION OF NUCLEAR WASTE. • HOWEVER, THE GENERAL PUBLIC IS WOEFULLY IGNORANT ABOUT THE SITUATION. • IN EUROPE, WHERE NUCLEAR POWER IS USED MORE THAT IN THE U.S., NUCLEAR WASTE AMOUNTS TO LESS THAT 1% OF ALL TOXIC WASTE GENERATED. • NUCLEAR WASTE FALLS INTO THREE CATEGORIES: • LOW LEVEL – WASTE FROM MEDICAL USE AND RESEARCH. DISPOSED OF IN SPECIAL LAND FILLS. • HIGH LEVEL – WASTE FROM NUCLEAR POWER PLANTS – STORED ON SITE. • HIGH LEVEL – WASTE FROM MILITARY FACILITIES – SPECIAL LAND FILLS AND UNDERGROUND

  4. Low level radioactive waste is disposed safely today. Aerial and side view of the cell at the Clive, Utah, low-level radioactive waste site.

  5. TWO STRATEGIES FOR HANDLING HIGH LEVEL WASTE FROM REACTORS • REPROCESSING • DIRECT DISPOSAL • USED FUEL CONTAINS TWO TYPES OF RADIOACTIVE MATERIALS • FISSION PRODUCTS, WHICH ARE USUALLY ISOTOPES OF Ba, Sr, Cs, I, Kr, and Xe. THESE ARE SHORT LIVED AND VERY RADIOACTIVE • TRANSURANICS FORMED BY NEUTRON CAPTURE SUCH AS Pu-239, Pu-240, Pu-241, and U-236. THESE ARE NOT AS RADIOACTIVE, BUT HAVE VERY LONG HALF LIVES.

  6. A NEWLY DISCHARGED FUEL ASSEMBLY IS SO REACTIVE THAT IT EMITS SEVERAL 100 KILOWATTS OF HEAT. • AFTER 1 YEAR, IT IS DOWN TO 5 KW • AFTER 5 YEARS IT IS DOWN TO 1 KW • AFTER 40 YEARS ONLY 1/1000 OF THE ORIGINAL RADIOACTIVITY • IF USED FUEL IS REPROCESSED, ONLY ~3.5% IS LEFT AS HIGH LEVEL WASTE. • THIS CAN BE DRIED AND VITRIFIED INTO BOROSILICATE GLASS FOR EVENTUAL STORAGE DEEP UNDERGROUND.

  7. IF THE FUEL IS NOT REPROCESSED, THE ENTIRE FUEL ASSEMBLIES ARE STORED. THESE ARE STORED UNDER WATER FOR SEVERAL YEARS TO ALLOW THE FISSION PRODUCTS TO DECAY. THEN, THEY ARE STORED IN LARGE CONCRETE AND STEEL CONTAINERS WEIGHING 100 TONS EACH. THESE CAN BE USED FOR STORAGE AND TRANSPORTATION. COUNTRIES TAKING THIS APPROACH ARE THE U.S., CANADA, FINLAND, AND SWEDEN. THE U.K., FRANCE, JAPAN, INDIA, AND RUSSIA REPROCESS THEIR FUEL.

  8. Commercial spent fuel in reactors can be stored safely Spent fuel pool storage at reactors Above-ground fuel storage containers

  9. Numerous collision and drop tests have proven the safety of casks to transport and entomb nuclear waste.

  10. USED FUEL CONTAINS ~1% U235. A 1000 MWT LIGHT WATER REACTOR PRODUCES ~27 TONS OF USED FUEL A YEAR. 90,000 TONS OF USED FUEL HAS BEEN REPROCESSED SO FAR. THE REMAINING MATERIAL AFTER REPROCESSING THIS 90,000 TONS WOULD FIT IN AN AREA 20 METERS X 20 METERS X 16 METERS HIGH. FACILITIES ARE AVAILABLE TO REPROCESS ~5,000 TONS PER YEAR. VITRIFIED WASTE IS USUALLY KEPT ~50 YEARS BEFORE FINAL STORAGE TO ALLOW THE SHORT-LIVED ISOTOPES TO DECAY.

  11. ~20 MILLION SHIPMENTS OF NUCLEAR MATERIAL OCCUR EACH YEAR. GLOBALY, THERE ARE 440 NUCLEAR POWER REACTORS IN 30 COUNTRIES, SO TRANSPORT IS AN INTEGRAL PART OF THEIR OPERATION. SINCE 1971, THERE HAVE BEEN 7,000 SHIPMENTS OF USED FUEL AMOUNTING TO 35,000 TONS. NO BREACH OF CONTAINERS OR INJURY TO PERSONNEL HAVE OCCURRED. TYPE B CANNISTERS WEIGH ~100 TONS AND CAN HOLD UP TO 6 TONS OF USED FUEL. CANNISTERS SERVE A DUAL PURPOSE – FOR STORAGE AND SHIPMENT.

  12. UTILIITY CUSTOMERS BUYING POWER FOR NUCLEAR PLANTS PAY 0.1 CENT PER KWH FOR WASTE DISPOSAL. THIS IS NOT THE CASE FOR COAL FIRED POWER PLANTS. THE U.S. HAS ACCUMULATED $25 BILLION IN A FUND FOR HANDLING NUCLEAR WASTE DISPOSAL. HOWEVER, NO POLITICAL DECISION HAS BEEN MADE. NIMBY OR NIMEY

  13. SO, LET’S LIST OUR POSSIBILITIES: • REPROCESS AND STORE OR DISPOSE OF REMAINING WASTE • STORE AND DISPOSE OF FUEL ASSEMBLIES • IN WASTE, YOU HAVE • - HIGH LEVEL FISSION PRODUCTS • - LONG-LIVED TRANSURANICS • BY 1,000 YEARS ALMOST ALL OF THE SHORT-LIVED FISSION PRODUCTS HAVE DECAYED, AND THE ACTIVITY IS APPROXIMATELY THAT OF URANIUM ORE.

  14. FOR EITHER CHOICE, THE DISPOSAL STEPS SHOULD BE: • CONVERT TO INSOLUBLE FORM (VITRIFICATION) • SEAL IN CORROSION RESISTANT CONTAINERS • IN WET ROCK, PACK W/BENTONITE CLAY TO INHIBIT GROUND WATER MOVEMENT • BURY DEEP UNDERGROUND (500 METERS) IN A STABLE ROCK STRUCTURE.

  15. URANIUM MINE SITE AT OKKO, GABON SCIENTISTS FOUND THAT NATURAL REACTORS OPERATED AT OKKO FOR ~2 MILLION YEARS. THE ORIGINAL U235 HAD BEEN ABOUT 3.5% IN AREAS HERE. AFTER REACTING, 5.4 TONS OF FISSION PRODUCTS AND 2 TONS OF PLUTONIUM HAD BEEN FORMED. THE NATURAL CLAY FIXED THESE ISOTOPES IN PLACE. THIS IS THE ONLY KNOWN TEST OF LONG TERM WASTE DISPOSAL, AND IT WAS IN A WATER LOGGED SHALE/SANDSTONE FORMATION.

  16. The proposed Yucca Mountain Nuclear Waste Repository near Las Vegas, Nevada

  17. A deep geologic repository for the final disposal of nuclear waste will use natural geologic barriers to isolate the waste, essentially for a very long time. Natural barriers provide isolation for the proposed Yucca Mountain repository

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