2/25/2013 BOARD OF SELECTMEN Minutes

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surface of the pipe as it moved onto a the problems that can occur by irradiat- and heavier elements than standard low- nozzle with a larger diameter.The result- ing them for an extended period of time. enriched uranium fuel, it could increase ing air gap masked signs of the crack. For example,high burn-up fuels are more the number of deaths resulting from a Other inspection methods that are not vulnerable to damage during certain types severe accident by 25 to 100 percent,de- vulnerable to this problem would have of design-basis accidents,including those pending on whether the plutonium detected the crack earlier. where coolant is lost or control rods are comes from weapons or spent reactor ejected.I The NRC has now known about fuel." MOX fuel should therefore be 11. 7he NRC should require plant these problems for more than a decade banned, and excess plutonium from owners to periodically inspect equip- but is responding slowly due to industry weapons should be blended with radio- _ ment outside the scope of normal active waste,encased in glass or a ceramic inspections, both to determine whether material, and disposed of in a long-term that scope is appropriate and to detect The use of mixed- repository. problems before safety margins are compromised, oxide fuel increases the Ensuring the Continued Safety Because monitoring every square inch of probability of certain of Reactors with Renewed Licenses a nuclear plant would be impractical,in- When the NRC revises regulations or spections target equipment and structures types of severe accidents adopts new ones(as when a generic safety considered most vulnerable to degrada- issue has been resolved), it sometimes tion.When workers discover degradation and the magnitude of "grandfathers"(or exempts)existing reac- outside the scope of their inspections,the the environmental and tors from these regulations.For example, scope is enlarged to include the suspect in 1985 the NRC required new reactors equipment or plant areas in all future health impacts of such to incorporate design features that would inspections.However,the NRC does not a severe accident. make their sump screens less likely to require plant owners to periodically in- become clogged with debris during an spect equipment and structures consid- accident,but exempted existing reactors. CC' ered less vulnerable! Such exemptions continue to apply even I� For example, in 2002 operators shut resistance. As a result, a significant when a reactor receives a 20-year license down Unit I at Illinois'Quad Cities nu- quantity of fuel in U.S. reactors today extension, despite the fact that aging clear plant when the beam holding down may not be able to withstand design-basis a pump inside the reactor vessel broke accidents. ervac apart and pieces of the beam damaged a one of the other pumps. Workers had 13. 7be U.S.government should , w. I` frequently inspected the beam at its prohibit the use ofplutonium-bearing two ends, where it was believed cracks mixed-oxide(MOX)fuel in reactors, EiBD were most likely to form, but the beam and end the program to produce MOX cracked in its middle. Had the scope of fuel from excess weapons plutonium. these inspections occasionally extended The United Slates is currently construct- r to the entire beam,the crackwould like) - t y ing a facility that would produce MOX a have been discovered before the beam fuel for commercial reactors using the broke apart. plutonium from dismantled nuclear l _ weapons,and the French company Areva 12. 7be NRC should revue its regma- has proposed to build a U.S.facility that tions for the licensing of`high burn-up" would reprocess spent fuel and use the ' r fuel to ensure public safety, and restrict resulting plutonium to make MOX fuel. how this fuel is used until the revisions However, the use of such fuel increases are complete. the probability of certain types of severe I Over the last couple of decades, reactor accidents (such as those in which core e' owners have increasingly used high burn- damage would result from the ejection of up fuels that can be left in the reactor for control rods) and the magnitude of the r° a longer period of time, allowing fuel to health and environmental impacts of such be replaced every other year rather than a severe accident.10 By requiring workers to periodically inspect equipment outside the scope of normal inspections, once a year.However,the NRC approved Because MOX fuel contains greater more problems will be detected before safety these fuels without fully understanding amounts of highly radiotoxic plutonium margins are compromised. U.S. NUCLEAR POWER AFTER FUKUSNIMA 9