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Published byRudolf Singleton Modified over 9 years ago
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Agenda Background Update on Fukushima Daini Update on Fukushima Dai-ichi – Summary of Events at Fukushima Dai-ichi Summary of Radiation and Reports
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Boiling Water Reactors (BWRs)
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Fukushima Daini Units 1, 2, and 3 are in cold shutdown status – Pressure is near atmospheric – Temperature is below 100 ° C Unit 4 is still being actively cooled – No signs of trouble
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Fukushima Dai-ishi Unit 1: 460 MW, 1967 Unit 2: 784 MW, 1969 Unit 3: 784 MW, 1970 Unit 4: Shutdown, unfueled. 11/10 Unit 5: Shutdown, fueled. 1/11 Unit 6: Shutdown, fueled. 8/10
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Fukushima Dai-ichi Unit 1 SCRAM – immediate shutdown following the earthquake External power was lost Diesel generators started backup cooling Diesels failed due to tsunami damage Reactor Core Isolation Cooling (RCIC) pumps continued to operate on steam from the reactor Batteries drained, losing power to valves Complete blackout
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Primary water was lost and core degradation occurred Zirc alloy oxidizes, resulting in hydrogen formation Fukushima Dai-ichi Unit 1
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Portable diesel generators are delivered, backup pumps replace water to the Reactor Pressure Vessel Pressure in containment drywell rose as wetwell became hotter Fukushima Dai-ichi Unit 1
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Pressure was relieved to the reactor building, gasses included hydrogen produced from zirconium oxidation Hydrogen in the reactor building exploded, causing the collapse around the containment. Fukushima Dai-ichi Unit 1
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Began injecting seawater into the vessel to continue the cooling process Similar events happened at Units 2 and 3 Fukushima Dai-ichi Unit 1
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Fukushima Dai-ichi Unit 2 An explosion at Unit 2 may have damaged the suppression pool A fire at the Unit 4 fuel pool has led to a radiation release – The fire is extinguished and radiation levels are decreasing steadily
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Radiation Levels REM (Radiation Equivalent Man) 100 REM = 1 Sievert Normal, Background Comic, Terrestrial Medical – Chest X-Ray: 10 mREM – Abdominal CT: 2000 mREM
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Average Dose in U.S.: 620 mREM/year
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Radiation Reports 8 times normal: – 0.059 mREM/hr 1000 times normal: – 7 mREM/hr Maximum levels – On site: 40 REM/hr – Boundary: 1.2 REM/hr – Dose: 10.6 REM
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Acute Radiation Sickness Whole Body < 100 REMs – 25 REMs: Possible changes in blood cells – 50 REMs: Consistent changes in blood cells Decrease in size of lymph glands – 80 REMs: 50% chance of temporary sterility in males 100 – 200 REMs – Symptoms begin at 100 REMs and become common (50% chance) at 200 REMs – Mild to moderate nausea – Occasional vomiting (3-6 hrs) – Loss of appetite – fatigue
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Radiation Check
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Last Thoughts Our thoughts and prayers go to those who have lost their lives and livelihood in this disaster. We wish the best for those still working at the plants. They are our first responders. They are heroes.
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Nuclear Fission
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Future of Nuclear Power
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