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than one. In addition to the double-wallcontainment, the plant’s reactor building,the spent fuel building, and two of thefour safeguards buildings, which housesystems such as the safety injection systemand the emergency feedwater system, areprotected by geographical separation.In addition, the diesel generators are intwo geographically separate buildings toavoid common failures.5. How can we convince a US citizenin simple language that an accident suchas one at Three Mile Island cannot occurwith an EPR?Three Mile Island was an importantevent in the history of nuclear energyin this country. It was caused by acombination of equipment failure and theinability of plant operators to understandthe reactor’s condition at certain timesduring the event.I spent some time there after theevent with a company that designedequipment to look at the bottom of thereactor vessel post-accident. We removed14 prism-shaped metallurgical specimenswhich were carefully analyzed by aninternational team. The interesting thingis that the reactor vessel even under thosesevere conditions performed admirably.There was no degradation. The equipmentstill performed the way it was supposedto. The plant shut down safely, and therewas no harm to the public.Since then there has been thecreation of the Institute of Nuclear PowerOperations and a systematic assessmentof the performance of all the licensees.We as an industry have gotten muchbetter at reviewing and developing notjust hardware but implementing bettertraining, better operator recognitionof situations and incidents, and betterperformance.The enhanced safety features of theU.S. EPR TM help reduce the probabilityof severe accidents that could cause acore melt and limit the consequences ofa severe accident. The probability of anaccident that would cause damage to areactor core is measured in core damagefrequency or CDF. The core damagefrequency in the EPR is 10 -7 . So, that’sone in 10 million chance of occurrence.6. What are the lessons learned atOlkiluoto 3 and what is being doneto ensure that those problems are notrepeated in the US EPR?The really important things tounderstand about Olkiluoto 3, I wouldcategorize in several areas. First, thepopulation of the country of Finland isabout the same as the city of Chicago.To draw on the types of resourcesneeded from a technical and regulatorystandpoint from that small of a populationis a challenge. Second, the commercialoperation date of the last Olkiluotoplant to go operational was 1982. If youthink about trying to stand up that sortof regulating environment for new plantconstruction, STUK (the Finish versionof the NRC) really had a tall order tobe prepared to oversee the developmentof the plant. Third, construction wasstarted even though the detailed designengineering phase of the project was lessthan 10 percent complete. It’s not a veryefficient way of building a project. You(Continued on page 44)TriVis Inc.The complete solution providerNuclear Plant Journal, July-August 2010 www.NuclearPlantJournal.com 43