Safety Measures at New England Nuclear Plants

Safety measures at New England nuclear plants BOILING-WATER REACTORS Pilgrim Station in Mass., Vermont Yankee Station in Vt. Spent fuel pool Both Pilgrim and Vermont Yankee place spent fuel rods – which must be immersed in water to prevent radioactive release - in upper levels of the building. Containment structure Pilgrim Station has a 1/2" thick primary steel liner and a 5-foot thick reinforced concrete Emergency cooling Entergy-owned Vermont Yankee and Pilgrim have eight hours of battery power, diesel generators to recharge those batteries and additional containment wall. Control rods They can be raised between the fuel rods to control or stop the generator on top of that system to run the plant. reaction. Resistance to natural disasters Official say both stations can handle a more than 6 magnitude earthquake. Vermont Yankee can handle floodwaters over 30 feet, an 80 m.p.h. hurricane and a 300 m.p.h. tornado, while Pilgrim can withstand 131 mile per hour winds and an 18.3 feet storm surge. PRESSURIZED-WATER REACTORS Seabrook, N.H. Containment structure An inner and an outer dome of almost 6 feet of steel- reinforced concrete with an additional 3/8" steel liner on the inside. The two domes are separated by a 5' air space that provides additional robustness. Control rods Spent fuel pool Spent fuel rods are placed in a pool in a building adjacent to the dome (reactor). Emergency cooling Seabrook also has backup batteries and diesel generators. Resistance to natural disasters Reactor vessel The primary steel container is 8" thick, with uranium pellets inside steel zircaloy rods. Seabrook is located 20 feet above sea level and 2 miles from the ocean. A huge wave force would dissipate as it crosses a marsh and a bridge. SOURCES: Vermont Yankee, Pilgrim Nuclear Station and Seabrook Station ELIZABETH DALEY, MONICA ULMANU, JAVIER ZARRACINA/GLOBE STAFF