PHYSICS AT THREE MILE ISLAND AND CHERNOBYL Eric P. Loewen, Ph.D. VP/President-Elect American Nuclear Society

February 17, 2011 City College of New York About ANS

Professional organization of engineers and scientists devoted to the applications of nuclear science and technology 11,500 members come from diverse technical backgrounds Dedicated to improving the lives of the world community within government, academia, research laboratories and private industry AMEX August 15, 2007 Esquire Magazine, 2009 Times Square, 2010 The American Nuclear Society Challenging Times

Stationary Low Power Reactor One (SL-1) Incidents: Three Mile Island Chernobyl Fission Energy: Fast and Slow Challenging Times

Station Land Reactor-One January 3, 1961 Movie Break

AEC SL-1 Movie

This movie has been donated to the City College of New York. SL-1 Site SL-1 Reactor Building Section Top of Reactor Afterwards SL-1 Reactor Perspective SL-1 United States Army experimental nuclear power reactor 3 MWt (200 kWe) January 3, 1961 underwent a steam explosion and meltdown Removal of single caused reactor to go prompt critical Power jumped to 20 GW in 4 minutes SL-1 Take-Aways

Design such that one control rod withdrawal will not bring reactor critical Operators are required to monitor the reactor plant New materials have been developed SL-1 Take-Aways (Cont.)

Cold shut down conditions can lead to higher control rod worth Prompt criticality can disperse fuel at high temperatures in the coolant and cause steam explosions Movie Break

SNL Metal/Water Experiments

This movie has been donated to the City College of New York. Challenging Times

Three Mile Island March 27, 1979 Fission Energy: Fast and Slow Neutrons Pressurized Water Reactor Simplified PWR Showing Three Mile Island Release Paths TMI Lessons Learned

Industry is only as strong as the weakest plant Institute of Nuclear Power Operation (INPO) started Plant simulator use increased TMI Lessons Learned (Cont.)

Conduct of plant operations formalized Degreed person required in control room Safety systems worked; no one was harmed Challenging Times

Chernobyl April 26, 1986 Fission Energy: Fast and Slow Neutrons Chernobyl Nuclear Power Plants

Population of Chernobyl was 49,000 Each unit is rated at about 3,200 MWth (four units) Direct-cycle, boiling- water, pressure-tube reactors. Steam is produced within the assembly Chernobyl Plant Characteristics

The reactor fuel rods (~1,700) are each contained in individual zircaloy pressure tubes embedded in a matrix of graphite blocks

Each pressure tube contains 18 zircaloy-clad UO2 fuel pins, enriched to 1.8% U-235 Reactor is 40 feet in diameter and 26 feet high On-line refueling at a rate of about one assembly/day USSR RBMK – 1000 Final Scenario

1:23:02 Test begins at reactor power of 200 MWth. 1:23:04 Power in the reactor increases (500 MWth) due to void buildup and pressure increases; eight reactor coolant pumps still operating. 1:23:31 Operator manually initiates reactor scram, but it is too late, since 15-20 seconds are required for control rod insertion. Seconds Later

1:23:40 Reactor is now on a high power, short period ramp, and reactor power reaches 110% normal (estimate). 1:23:43 Doppler feedback curtails first burst. At the End

1:23:44 Second rector excursion to four times normal (estimate). (Fuel in channels, void complete, flow blocked.) 1:23:45 Pressure falls and reactor coolant pump flow returns to core; two audible/visible explosions observed. Aftermath

Reactor shield block destroyed and all 1,700 pressure tubes severed The audible explosions caused by a succession of events in sequence: . Transient overpower reactor excursion . Loss of flow . Fuel-coolant interaction . Hydrogen production . Hydrogen combustion Aftermath, continued

Fuel hydrodynamic dispersal occurred, and eventual melting and slumping of remainder of fuel took hours The graphite fire followed all of these rapid events and contributed to the long-term radioactivity release Chernobyl Lessons Learned Movie Break

SPERT EXPERIMENTS

This movie has been donated to the City College of New York. Other Energy Accidents Other Energy Accidents: Oil

An explosion and fire ruptured a pipeline between an oil tanker and a PetroChina facility in China’s Dalian port in the Liaoning province, releasing an estimated 315,000 to 365,000 barrels of oil into the Yellow Sea. Photo courtesy of Imaginechina/Zumapress.com Other Energy Accidents: Gas

A natural gas pipeline exploded, setting off a blaze that destroyed a San Bruno, California neighborhood, killing eight people and wrecking 37 homes. Photo courtesy of Dan Honda/Zuma Press Other Energy Accidents: Coal

Twenty-nine miners died after an explosion at the Pike River coal mine in New Zealand on November 19. Photo: Xinhua/Zumapress.com Other Energy Accidents: Wind

Windmill on fire in Palm Springs, California. Photo courtesy of Metacafe.com. Other Energy Accidents: Oil

Off shore oil rig explosion off the Louisiana coast takes 11 lives. Photo courtesy of UPI. Other Energy Accidents: Hydro

Sayano–Shushenskaya hydroelectric power station accident in Russia take 76 lives. Photo courtesy of the Daily Mail. What Now? Join ANS! Thank You!

For more information contact the ANS Public Outreach department at 800-323-3044 or visit ww.ans.org.