Richland, Wash. — Workers at the Hanford Waste Treatment Plant, also known as the Vit Plant, have received the first of 87 specially designed, leaded-glass shield windows for the Pretreatment, High-Level Waste Vitrification, Low-Activity Waste Vitrification facilities and the Analytical Laboratory.
The windows are designed to work as a barrier between the radioactive and nonradioactive areas of the facilities and will allow operators to safely observe the work going on in the radioactive hot cells. The first shipment of 22 windows is for the Analytical Laboratory.
"The windows are an important aspect of operational safety at the plant and serve as a barrier between the facility workers and the work being completed in the hot cells of the Lab," said Jason Young, Federal Project Manager for the Analytical Laboratory.
Each individual shield window weighs 7,200 pounds, is 16 inches thick and measures 75 inches wide, by 65 inches tall. The windows themselves have a yellow tint and are made of borosilicate glass and lead.
The windows were manufactured by Hot Cell Services Corporation of Kent, Wash.
"The supplier was one of the few manufacturers in the world who could provide these type of windows," said Lori Baker, Manager of Procurement and Subcontracts. "We are fortunate the supplier is so geographically close to the project. Due to the temperature control requirements for the windows, transportation and warehousing are critical elements for material handling."
The windows are temperature sensitive. Although they can withstand extreme minimum and maximum temperatures, they cannot withstand a temperature change of plus or minus five degrees in a one-hour timeframe," said Baker.
The shield windows will be one of the last items to be placed in the Laboratory, and will be stored in a controlled environment until they are installed in the fall of 2013. The long lead time on the procurement is necessary because it takes a year to manufacture the windows.
The balance of the windows will be delivered in the next two months. Once installed, the windows will go through yearly maintenance and testing.
Bechtel National Inc. is designing and building the world's largest radioactive waste treatment plant for the U.S. Department of Energy at the Hanford Site in southeastern Washington state. The Waste Treatment and Immobilization Plant, also known as the Vit Plant, will immobilize the radioactive liquid waste stored in 177 underground tanks using a process called vitrification.
Vitrification involves blending the waste with molten glass and heating it to high temperatures. The mixture is then poured into stainless steel canisters. In this glass form, the waste is stable and impervious to the environment, and its radioactivity will dissipate over hundreds to thousands of years.
The Vit Plant will cover 65 acres with four nuclear facilities — Pretreatment, Low-Activity Waste Vitrification, High-Level Waste Vitrification and Analytical Laboratory — as well as operations and maintenance buildings, utilities and office space. Construction of the Vit Plant began in 2001 and is more than 65 percent complete.