1. THREE MILE ISLAND NUCLEAR MELTDOWN 1979 RACHAEL NAEGER MELISSA ELLIOTT JENNA CLACK ALYSSA BRYANT

2. INTRODUCTION Middletown, Pennsylvania May 1968 Three Mile Island (TMI) Unit 1 Construction began November 1969 TMI Unit 2 Construction began Unit 1 began operation in September 1974 Unit 2 started up in December 1978 Within 90 days, on March 28, 1979, a nuclear meltdown occurred in TMI 2 A non-nuclear failure led to a nuclear meltdown Worst accident at a nuclear power plant in the history of U.S. commercial power plants

3. NUCLEAR REACTOR MAIN COMPONENTS Fuel Source: Uranium Moderator to slow the release of neutrons of the Uranium Typically water Control rods to absorb neutrons and control the rate of reaction Coolant to transfer heat from the reactor core Steam generator that is part of the coolant system Containment to protect outside from radiation and core from foreign particles

4. PROCESS DESCRIPTION Reactor splits atoms of elements to release heat Splits the Uranium atoms Moderator slows the release of neutrons and control rods absorb neutrons Heat is captured in gas or water (the coolant) Transfer from the reactor to steam generator This is used to create steam The steam is used to drive a turbine and create electricity

5. TMI UNIT 2 DIAGRAM

6. TIMELINE Video 4:00 AM March 28, 1979 Initial Problem - Secondary cooling circuit stopped flowing Valves closed due to water leak into air line Secondary pipes boiled dry Prevented primary coolant from removing heat from core Automatic shutdown occurred Relief valve in primary loop failed to close Two valves manually closed two weeks prior for maintenance so water unable to flow Loss of coolant occurred and relief valve opened Plant experienced: uncovered core, hydrogen gas generation, radioactive primary coolant on reactant-building floor

7. TIMELINE (CONTINUED) Pressure in primary unit was high Operators over-rode emergency core-coolant system and shut off pumps Valves closed for cleaning were opened to move cooling water into boiling region, but water turned to steam Pumps began to vibrate Operators shut down pumps and ended forced cleaning to prevent damage to pumps Temperatures failed to decrease due to gas and hydrogen pockets in system Operators had gas transferred to hold-up tanks in another building Pipe transferring gas leaked to atmosphere Sudden build-up in pressure indicated hydrogen burn occurred Operators periodically opened vent in the reactor to cool slowly (one month) Cooled by natural movement of water, no mechanical movement

8. EVACUATION Inadequate evacuation plans in place At first, no evacuation was called for Public confusion On Friday, March 30, Governor called for a limited evacuation

9. ULTIMATE RESULTS No fatalities or injuries Radiation exposure ~ 0.3 - 0.6 rem No conclusive evidence for an increase in cancer cases Unit 2 not allowed to resume operation Unit 1 not allowed to resume operations until 1985 General Public Utilities paid $82 million as compensation Negative media coverage Property values dropped Mistrust of Nuclear Industry Loss of income for surrounding farms

10. CLEAN-UP Lasted 14 years Vented 44,000 curies of radioactive gases Water decontamination Removal of solid waste Cost ~ $1 billion

11. LESSONS LEARNED New Regulations Inherently Safer Design and Operation Emphasis on Training and Transparency Creation of INPO Expect the Unexpected

12. SUMMARY Worst Nuclear Industry accident in U.S. history No injuries or fatalities Major changes to the industry New research into what causes a core meltdown Fed public mistrust of nuclear industry

13. REFERENCES 1 Kemeny, John G. The Accident at Three Mile Island. Rep. Washington D.C., 1979. The Accident at Three Mile Island. Web. 23 Feb. 2012.. 2 "Backgrounder on the Three Mile Island Accident." NRC:. Web. 23 Feb. 2012. 3 "Three Mile Island Accident." Three Mile Island. Web. 01 Mar. 2012.. 4 Del, Tredici Robert. The People of Three Mile Island. San Francisco: Sierra Club, 1980. 5 Flynn, Cynthia B. The Social and Economic Effects of the Accident at Three Mile Island. Rep. no. NUREG/CR-1215. Print. 6 Osif, Bonnie A., Anthony John Baratta, and Thomas W. Conkling. TMI 25 Years Later: The Three Mile Island Nuclear Power Plant Accident and Its Impact. University Park, PA: Pennsylvania State UP, 2004. 7 "Backgrounder on the Three Mile Island Accident." NRC:. Web. 01 Mar. 2012.. 8 King, Lester J., and James H. Opelka. "Three Mile Island Cleanup: Experiences, Waste Disposal, and Environmental Impact." 213.78 (1982). 9 Walker, J. Samuel. Three Mile Island: A Nuclear Crisis in Historical Perspective. Berkeley: University of California, 2004. Print. 10 "News." Three Mile Island: 30 Years of What If... Web. 01 Mar. 2012.. 11 Toth, L. M. The Three Mile Island Accident: Diagnosis and Prognosis : Developed from a Symposium Sponsored by the Division of Nuclear Chemistry and Technology at the 189th Meeting of the American Chemical Society, Miami Beach, Florida, April 28-May 3, 1985. Washington, D.C.: American Chemical Society, 1986. Print. 12 Hargreaves, Steve. "First New Nuclear Reactors OK'd in over 30 Years." CNNMoney. Cable News Network, 09 Feb. 2012. Web. 01 Mar. 2012.. 13 Greenwire, PETER BEHR,. "Three Mile Island Still Haunts U.S. Nuclear Industry." The New York Times. The New York Times, 27 Mar. 2009. Web. 01 Mar. 2012..

14. QUESTIONS?