A Rich Resource Requires Recovery

Posted: July 22, 2013 - 3:33pm | Y-12 Report | Volume 10, Issue 1 | 2013

Recovering uranium from manufacturing processes and from disassembled and dismantled weapons helps ensure an effective stockpile and is a key element of Y‑12’s weapons work. “We must optimize the use of this extremely valuable material since the quantity is limited,” said Brian Gullett of Stockpile Programs.

For Y‑12, reusing manufacturing byproducts is not new. Since the early years, uranium left behind in machining chips, equipment filters and other items was collected to undergo another round of processing by dissolution, extraction/purification and conversion to purified metal buttons. Such buttons of the highest quality uranium metal are used in the process of casting weapon components and in meeting other customer specifications.

Recovery and reuse are not limited to the byproducts from manufacturing. Materials from canned subassemblies returned to Y‑12 for refurbishment also are recycled.

Uranium from Canned Subassemblies

Disassembling canned subassemblies is complex work if refurbishment is to follow. As parts are removed, they are segregated by material type and stored. When it is time for processing, the enriched uranium metal is removed from storage and melted to cast a new uranium part. After machining, inspection, recertification and unique numbering, the component can be placed into a canned subassembly.

Management and Storage

When enriched uranium materials are not needed immediately, they are maintained in safeguarded areas such as the Highly Enriched Uranium Materials Facility.

Factored into management and storage are Presidential Declarations defining which nuclear materials are to be forever removed from weapons use, which are to be kept in reserve and which can be supplied to customers such as naval, research or commercial reactors.

Careful planning and analysis ensure that the supply of enriched uranium can meet future customer requirements for quantity and quality.

Customers

While enriched uranium is essential to the National Nuclear Security Administration’s Defense Programs, it also fuels U.S. Navy nuclear submarines and aircraft carriers and is made available to other government and commercial customers.

Since the early 1990s, more than 134 metric tons of enriched uranium have been blended with natural or depleted uranium to produce commercial reactor–grade uranium. The Tennessee Valley Authority, for example, has used low-enriched uranium in its Browns Ferry and Sequoyah nuclear plants in Alabama and Tennessee, respectively. Other downblended enriched uranium has been placed into reserves, such as the American Assured Fuel Supply and the Mixed Oxide Backup Low-Enriched Uranium Inventory, which utilities could use if fuel supplies were disrupted.

The U.S. annually supplies about 1.5 metric tons of low-enriched uranium to research, space and isotope-production reactors around the world. That quantity is forecast to increase as several large research reactors convert to low-enriched uranium fuel. Unlike the low-enriched uranium commonly used as fuel in commercial nuclear power reactors, low-enriched uranium for research reactors is available in the U.S. only from Y‑12 because of the higher levels of uranium-235 required.

A Strong Stockpile

After years of disassembling and dismantling canned subassemblies, Y‑12 is the linchpin in the preservation of high-quality enriched uranium. Glenn Pfennigwerth of Operations Engineering said, “The uranium we have is the uranium we have, and we work hard to retain it. Even though the existing weapons stockpile is smaller than during the Cold War years, by refurbishing weapons, we continue to maintain a strong and proficient arsenal to protect the nation.”