By Walter Pincus
Washington Post Staff Writer
Friday, November 3, 2006; A09

“Significant backlogs” in surveillance testing of several types of nuclear warheads in the aging U.S. stockpile have created gaps in information needed to ensure that the weapons remain reliable, a report released yesterday by the Energy Department’s inspector general said.

Every year, a small number of missile warheads and bombs from the nine U.S. nuclear weapons systems are dismantled. Parts are subjected to laboratory and flight tests to verify they are safe, secure and reliable.

“The surveillance program’s role in assessing and ensuring confidence in the reliability of the weapons stockpile is increasingly important as the nuclear weapons stockpile ages,” Inspector General Gregory H. Friedman wrote to Energy Secretary Samuel W. Bodman.

But Friedman added: “As a result of the continuing backlog of surveillance tests, the department lacks vital information about the reliability of the stockpile . . . [and] as a result of testing delays, important operating anomalies or other defects could go undetected.”

Friedman said the department is “committed” to eliminating most of the testing backlog by September 2007, in part by upgrading facilities, updating safety studies and perhaps eliminating some test requirements. In one case, surveillance activities were delayed for six to seven months in 2004 because operations were halted over the loss of a computer disk containing classified materials.

Last year, the report said, laboratory tests were behind schedule for seven of the nine weapons systems and flight tests for six. Charts contained in the report show the greatest laboratory backlog was in the oldest warhead, the W-62, which was used on the Minuteman III intercontinental ballistic missile and is due for retirement. Of 36 lab tests planned, 13 had been completed by Sept. 30, 2005, the report said.

Of the more modern warheads, the W-88, the newest U.S. warhead found on the Trident submarine-launched ICBM, was scheduled for 29 lab tests — of which 23 were completed on schedule. The largest gap in flight tests was for the W-87, the warhead that is to replace the W-62 and the Minuteman III. Of eight tests planned for fiscal 2005, three had been completed.