Entombment of the Hanford Site Plutonium Production Reactors and Chemical Processing Plants

摘要

The Hanford Site in southeast Washington State was the nation’s first plutonium production facility. FromrnMarch 1943, when construction began on the Hanford Engineer Works, until the last of nine plutonium production reactorsrnwas shut down in 1987, the Hanford Site mission was to produce nuclear material for national defense. During thosern44 years, nine plutonium production reactors, alphabetically designated as B, D, F, DR, H, C, KE, KW, and N, andrnfive chemical processing (canyon) facilities, B Plant, T Plant, U Plant, REDOX, and PUREX, were built and operatedrnto produce approximately 74 tons of plutonium.rnWith the end of the Cold War, the Hanford Site mission changed from nuclear production to the cleanup of the radioactivernand hazardous waste that is the legacy of more than four decades of defense production. In 1999, the U.S. Department ofrnEnergy, Richland Operations Office established a vision for the Hanford Site that included two cleanup outcomes:rn(1) restore the Columbia River corridor and (2) transition the Central Plateau for long-term waste management. In Augustrn2000, the U.S. Department of Energy, Richland Operations Office unveiled “Hanford 2012 – Accelerating Cleanup andrnShrinking the Site – Restore the River Corridor; Transition the Central Plateau; Prepare for the Future,”1 a plan tornaccelerate cleanup along the Columbia River corridor and reduce the site from 1,517 km2 (586 mi2) to about 194 km2rn(75 mi2) on the Central Plateau. The entombment of the reactors by 2012 is part of the accelerated cleanup along the riverrncorridor, and determining the final disposition of the canyon facilities is a key element in transitioning the Central Plateaurnfor long-term waste management. Entombment of the reactors is currently under way and entombment is being studied as arnviable decommissioning option for the canyon facilities.rnThis paper discusses the role of the reactors and canyon facilities in nuclear materials production at the Hanford Site;rntheir construction, operation, and shutdown; and the current status of the entombment of these facilities as arndecommissioning alternative.