Photograph used for a story in the Daily Oklahoman newspaper. Caption: "Capt. Bryan Heirston does computer work."

Photograph used for a story in the Daily Oklahoman newspaper.

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "C.A. "Tony" Carr, vie president of United Rubber Workers Local 998 in Oklahoma City, sits outside union headquarters recently."

Photograph used for a newspaper owned by the Oklahoma Publishing Company. Caption: "Crowd at final game of Big Eight Tournament. OSU vs. Iowa State"

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "Nicole Bobek, the U.S. National Figure Skating champion, visits with Clentisha Jackson, left, and Amanda McKeown at Eugene Field Elementary School in Oklahoma City."

Photograph used for a story in the Daily Oklahoman newspaper.

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "The Hazardous Materials Unit at Station 5 works on a broken gas line."

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "The firefighters on Station 5's blue shift take a volleyball break."

Photograph used for a newspaper owned by the Oklahoma Publishing Company.

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "A decal on a Station 5 helmet commemorates the day that changed the firefighters' lives."

Photograph used for a newspaper owned by the Oklahoma Publishing Company.

Photograph used for a newspaper owned by the Oklahoma Publishing Company.

Photograph used for a newspaper owned by the Oklahoma Publishing Company.

Photograph used for a newspaper owned by the Oklahoma Publishing Company.

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "Firefighter Mike Foster washes the trucks at Station 5."

Photograph used for a newspaper owned by the Oklahoma Publishing Company.

Photograph used for a newspaper owned by the Oklahoma Publishing Company.

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "Lt. Tony Parker, Capt. Kevin Reece and Capt. Byron Heirston, from left, relax in the lounge at Station 5."

The US Department of Energy has established the Tank Waste Remediation System (TWRS) program to safely manage wastes currently stored in underground tank at the Hanford Site. A TWRS testing and development strategy was recently developed to define long-range TWRS testing plans. The testing and development strategy considered four alternatives. The primary variable in the alternatives is the level of pilot-scale testing involving actual waste. This study evaluates the cost benefit and risks associated with the four alternatives. Four types of risk were evaluated: programmatic schedule risk, process mishap risk, worker risk, and public health risk. The structure of this report is as follows: Section 1 introduces the report subject; Section 2 describes the test strategy alternative evaluation; Section 3 describes the approach used in this study to assess risk and cost benefit; Section 4 describes the assessment methodologies for costs and risks; Section 5 describes the bases and assumptions used to estimate the costs and risks; Section 6 presents the detailed costs and risks; and Section 7 describes the results of the cost benefit analysis and presents conclusions.

Photograph used for a newspaper owned by the Oklahoma Publishing Company.

Photograph used for a newspaper owned by the Oklahoma Publishing Company.

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "Bomb survivor Steve Pruitt, holds a piece of the ruined Alfred P. Murrah Federal Building."

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "Bombing victim Sharon Littlejohn, and her nephew, Justin Cooley, 8, read get-well cards from well-wishers."

Photograph used for a story in the Daily Oklahoman newspaper. Caption: "A thank-you sign, painted by a firefighter's wife hangs outside Station 5."