The Defense Department investigation into the mix-up that sent U.S. nuclear missile parts to Taiwan is of great interest to members of Utah's congressional delegation.

Sen. Bob Bennett, R-Utah, spent the past week in top-secret briefings at three nuclear weapons development laboratories as he anticipates changes in Senate committee assignments. Rep. Rob Bishop, R-Utah, represents the northern part of Utah, which includes Hill Air Force Base, where the shipment of wrong parts originated.

"It obviously represents something very significant," Bennett said Friday of what has become an international political incident. President Bush was compelled to acknowledge the error in a phone call Wednesday with Chinese President Hu Jintao. The Chinese are sensitive about U.S. military sales to Taiwan, which China considers a renegade province. The shipment was supposed to have been replacement batteries for helicopters.

Not only did the Taiwanese government not get the parts it ordered when shipping containers arrived in the fall of 2006, but it took the Pentagon nearly two years to figure out the mix-up, which became public Tuesday.

"I am willing to believe at the moment it was inadvertent," Bennett said of the mixed-up shipment. "That it got out of control concerns me."

Bennett said a week of "wallowing in issues nuclear" while visiting national laboratories in Albuquerque and Los Alamos, N.M., and the Lawrence Livermore National Laboratory in California, has given him "a renewed appreciation for the depth of care that we put into protecting the (nuclear) stockpile."

The parts shipment originated at Defense Distribution Depot Hill, which is run by defense contractor EG&G. The contractor's parent, URS Corp., is staying quiet about what happened, and all questions to the military about the incident are being referred directly to the secretary of defense.

Bennett said the fact the depot is run by a contractor does not concern him. The nuclear weapons program has been run by defense contractors since its beginnings during World War II. Someone seeking out U.S. military secrets "is going to find them out from an employee," which is why government workers in sensitive jobs, contract or otherwise, only know as much about their job as they need to.

Did the shipping clerk who sent the Minuteman missile fuses to Taiwan know what was in the boxes, or just mix up parts numbers? "That is the obvious question here," Bennett said. "We are only going to tell an employee what he or she needs to know to do their job."

Bishop said he was taken by surprise when the Air Force announced the mix-up in a news conference. "It may have been part of a diplomatic effort to make sure with China nothing was intended with this but that it was a real screw-up at this point."

Bishop, working in Utah this week, said briefings he received from military leadership at Hill showed no evidence the shipping mix-up was anything "more sinister."

Bishop said he does have long-held concerns about "how much contracting we do on certain issues" and that he is anxious to find out what happened to make sure procedural errors are corrected.

Bennett said he wants to know "as much as I can about the procedures that were followed that allowed this kind of mistake to be made; and what changes will be made to see that it doesn't happen again."

The depot at Hill that shipped the missile parts keeps an inventory of 218,000 unique items and shipped 1.4 million items, many of them to foreign countries, during fiscal 2007. All material at the depot is supposed to be inventoried quarterly, which increases questions about how the four shipped missile fuses could have been unaccounted for for almost two years.

Bishop said the government might be able to take a lesson from the private sector . "If it's simply a matter of reading bar codes, FedEx and UPS handle a whole bunch of those with bar codes pretty effectively. That may indeed be one of the things we need to look at."