Plutonium capable of being used in a nuclear weapon, conventional explosives, and highly toxic chemicals have been improperly packaged or shipped by nuclear weapons contractors at least 25 times in the past five years, according to government documents.

While the materials were not ultimately lost, the documents reveal repeated instances in which hazardous substances vital to making nuclear bombs and their components were mislabeled before shipment. That means those transporting and receiving them were not warned of the safety risks and did not take required precautions to protect themselves or the public, the reports say.

The risks were discovered after regulators conducted inspections during transit, when the packages were opened at their destinations, during scientific analysis after the items were removed from packaging, or — in the worst cases — after releases of radioactive contaminants by unwary recipients, the Center for Public Integrity’s investigation showed.

Only a few, slight penalties appear to have been imposed for these mistakes.

In the most recent such instance, Los Alamos National Laboratory — a privately-run, government-owned nuclear weapons lab in New Mexico — admitted five weeks ago that in June it had improperly shipped unstable, radioactive plutonium in three containers to two other government-owned labs via FedEx cargo planes, instead of complying with federal regulations that required using trucks to limit the risk of an accident.

Before shipping the plutonium, Los Alamos failed to properly complete a checklist of dangerous goods that FedEx requires customers to fill out, according to the Energy Department. It used air transport on the grounds that one of the other labs — located in Livermore, California — needed the plutonium urgently, according to the initial explanation that Los Alamos filed with the government on June 23.

But that claim of urgency was false, the recipient told the Center for Public Integrity. “There was no urgency in receiving this shipment — this notion is incorrect,” Lawrence Livermore National Laboratory spokeswoman Lynda Seaver said in an email message on July 13.

The incident — which came to light after a series of revelations by the Center for Public Integrity about other safety lapses at Los Alamos — drew swift condemnation by officials at the National Nuclear Security Administration in Washington, D.C., which oversees U.S. nuclear weapons work. It also provoked the Energy Department on June 23 to order a halt to all shipments out of Los Alamos, the largest of the nuclear weapons labs and a linchpin in the complex of privately-run facilities that sustains America’s nuclear arsenal. Shipments of non-hazardous, non-radioactive materials out of Los Alamos resumed July 14, according to NNSA spokesman Gregory Wolf.

The lab — which is operated and managed by an industrial consortium that includes Bechtel, BWXT Government Group, Inc., AECOM (since its 2014 acquisition of URS) and the University of California —  has since been allowed to ship things out only after specially scrutinizing every item, said Los Alamos spokesman Matthew Nerzig.

“All of those involved from the individual contributor level up the management chain have been held accountable through actions that include terminations, suspensions, and compensation consequences,” Nerzig added, without offering details. No radioactive contamination occurred in the June plutonium air shipments, which went to Livermore and Savannah River in South Carolina.

But the documents show that Los Alamos, in particular, has been a repeat offender in mislabeling its shipments of hazardous materials: In a previously undisclosed 2012 case, for example, it sent unlabeled plutonium — a highly carcinogenic, unstable metal — to a University of New Mexico laboratory where graduate students sometimes work, according to internal government reports. The plutonium accidentally was opened there, leading to a contamination of the lab that required cleaning by the university and disposal of the debris by Los Alamos.

Los Alamos told the government it was not primarily at fault in that episode because the shipment had originated elsewhere and been mislabeled before it reached Los Alamos. But it acknowledged that its personnel should have checked the package more closely before sending it onward.

In total, 11 of the 25 known shipping mistakes since July 2012 involved shipments that either originated at Los Alamos or passed through the lab. Thirteen of the 25 incidents involved plutonium, highly-enriched uranium (another nuclear explosive), or other radioactive materials. Some of the mislabeled shipments went to toxic waste dumps and breached regulatory limits on what the dumps were allowed to accept, according to the reports.

In many instances, there were no consequences for the associated private nuclear weapons contractors. One possible explanation is that responsibility for policing such hazardous shipments is fractured within the federal Transportation Department, with ground movements of nuclear weapons materials under the purview of the department’s Pipeline and Hazardous Materials Safety Administration and air shipments policed by its Federal Aviation Administration.

The Nuclear Regulatory Commission, which arguably has more experience with the handling and transport of radioactive materials than any other government entity, has no jurisdiction over nuclear weapons-related work by the NNSA or its contractors. Instead, the Energy Department (of which the NNSA is a semi-autonomous part) regulates all the sites on its own, as well as the contractors that manage them.

Patricia Klinger, a spokeswoman for DOT hazardous materials regulators, said in a telephone interview that ensuring that all shipments are accurately labelled is vital to emergency personnel, whose safety and ability to protect the public in the event of an accident rely on correct knowledge of whatever they’re trying to clean up or contain. But she did not respond to questions about why the department only rarely appears to have imposed fines.

Internal NNSA records indicate that in the 25 incidents since July 2012, contractors drew just three fines, for example. DOT fined the Energy Department’s Savannah River site $17,650 in 2016 for incomplete hazardous material descriptions and insufficient security training of personnel. The New Mexico Environment Department imposed an $80,100 fine against Los Alamos last year for an array of hazardous waste violations, including several shipments with unlabeled containers of hazardous waste and incomplete waste descriptions. Utah environmental regulators also fined Los Alamos $1,500 in 2015, when bolts holding hazardous waste containers shut came loose during a shipment to a dump in that state.

But in more than 20 instances, the contractors were not directly fined by regulators in enforcement actions stemming from the shipping errors, according to government reports.

Los Alamos tells Washington another lab’s pressure caused its mistake

In the most recent shipping snafus by Los Alamos, the Federal Aviation Administration and FedEx are still conducting investigations, according to FAA spokeswoman Lynn Lunsford and FedEx spokeswoman Jennifer Caccavo. But Lunsford said “the remedy will likely be administrative since government agencies don’t assess civil penalties against one another.”

“Ensuring the compliance of all packages in the FedEx network is a top priority, and we are working closely with the customer to determine what happened with these shipments,” Caccavo said.

Los Alamos’s June 23 report to the NNSA blamed one of the mistaken shipments on pressure from Livermore to provide the fissile material quickly. Normally, a shipment of plutonium would take shape over the course of three months and be delivered by ground, Los Alamos’s report said, “however, LLNL [Livermore] advised they needed this delivered within three days.”

But Livermore spokeswoman Seaver disputed Los Alamos’s excuse for making the mistake. Seaver said, “We have a single point of contact here who worked with LANL [Los Alamos] regarding this shipment and at no time was any urgency expressed.”

Asked about the discrepancy, Los Alamos spokesman Nerzig said in an email that “after a thorough internal investigation of the event, we found no evidence of time pressure to make the shipment.” But he did not provide any other explanation for the mistaken shipment or explain why Los Alamos had initially told the government that it was only responding to Livermore’s urgent demands.

Referring to the incident, Nerzig emailed that “the Laboratory has acknowledged this as a mistake, taken an initial set of actions to address the situation, and plans on taking additional measures to dramatically reduce the possibility of something like this from happening again.”

NNSA spokesman Wolf said the agency is looking closely at “the accuracy of initial reporting” by Los Alamos. He said a shipping facility employee had “failed to follow established procedures that would have prevented the improper shipments,” and that a thorough review by the lab of what it was about to send out “was bypassed.” In addition, checklists that FedEx requires customers to complete for dangerous goods “were not filled out properly,” he said.

“NNSA has uncompromising standards for our laboratories, plants, and sites to perform work in a safe and secure manner that protects our employees, our facilities and the public — and that includes shipping operations,” Wolf said. “We look closely at any errors in shipping to identify and correct deficiencies and make appropriate notifications to Congress, government agencies and the public when errors do occur.”

Nerzig also declined to comment about the July 2012 incident in which Los Alamos supplied unlabeled plutonium to the University of New Mexico’s nuclear engineering program, normally a direct academic pipeline to careers at Los Alamos and Sandia National Laboratories (which also works on nuclear weapons) in Albuquerque.

According to records obtained under the state’s Inspection of Public Records Act, the university had expected to receive “dummy” metal sheets without radioactivity that faculty used to test radiation detectors Los Alamos had commissioned the university to develop. Although students have access to the room, none were present during the contamination, Dianne Anderson, a university spokeswoman, said. The samples originated at Oregon State University and were not tested at Los Alamos before being shipped to the University of New Mexico, according to an internal government report that Los Alamos contractors submitted to the Department of Energy.

Oregon State University vice president Steve Clark said in an email that while his school is paid by Los Alamos to produce both radioactive and nonradioactive samples, it is “not able to determine conclusively” whether it was responsible for failure to note radioactive material in the package labeling.

When one of the samples crimped during handling, it released radioactive particles that contaminated the room that housed the detector, but no one was harmed, according to the Los Alamos report to the Energy Department. The lab was cleaned within a few days, but disposal and retrieval of the debris oddly took more than a year, according to University of New Mexico emails obtained by the Center.

Cathy Anderko, the university’s chief radiation safety officer at the time, told officials at Los Alamos in an Aug. 2013 email — 13 months after the incident — “wow — you really work fast.” She was being sarcastic, according to a source with knowledge of the situation. When the waste was shipped out a few weeks later, Anderko told members of the campus safety staff in an email that the disposal was “very difficult… due to the high radio-toxicity of the radionuclide.”

Asked in July about the gravity of the incident, UNM spokeswoman Anderson gave a different appraisal, however: “This low-level activity was easily removed,” she said.

The New Mexico Environment Department acts as the NRC’s surrogate in that state and licenses the University of New Mexico to possess radioactive materials for medical purposes and other uses. But it imposed no fine in this case due to the small quantity of plutonium involved, according to New Mexico Environment Department spokeswoman Allison Majure.

Contractors’ shipment record fails to improve

Ken Niles, an assistant director for nuclear safety in Oregon’s Department of Energy, said mislabeling of such shipments greatly complicates the task of first-responders in the event of accidents or spills. When caustic and radioactive items aren’t noted in the descriptions, he said, “That is a huge, huge error and mistake. There need to be some consequences for doing that, because they would be putting people at risk.”

In the past three months alone, however, nuclear weapons contractors have made at least three shipping errors besides the errant FedEx plutonium shipments, according to Energy Department records.

In June, the Pantex plant in Amarillo, Texas, accidentally shipped an unsafe quantity of high explosives to an unspecified off-site laboratory, according to an internal Energy Department report dated June 27. In May, the Y-12 National Security Complex in Tennessee shipped unlabeled radioactive materials to an unspecified destination, a DOE report said. And in May, Los Alamos sent inaccurately labelled highly acidic waste to a Colorado chemical disposal site, according to New Mexico Environment Department records. In Aug. 2014, Los Alamos was temporarily forbidden from shipping waste to the same Colorado dump after the lab sent two shipments with paperwork that didn’t note the highly corrosive and acidic makeup of the waste.

In its appraisal of Los Alamos’s performance for 2016, the NNSA singled out the accuracy of shipping descriptions as a weakness. “In two instances the Laboratory shipped weapon related product that did not meet labeling and marking quality requirements associated with shipping documentation,” the performance evaluation report said.

The previous December, shipping personnel at Savannah River sent a container of tritium gas – which is used to boost the potency of a nuclear detonation — to the wrong place. It was supposed to be shipped to Lawrence Livermore, but instead was delivered to Sandia. In an email message last week, Angeline French, a spokeswoman for Savannah River Nuclear Solutions, the contractors that operate the Savannah River site, said the company “maintains very high standards in the execution of the hundreds of hazardous materials shipments it conducts each year.” And in Sept. 2014, the contractors that operate the Nevada National Security Site sent unlabeled radioactive material to their own satellite office at Livermore, which lacked a radiation control expert trained to reckon with such a surprise, according to an internal Energy Department report.

The Nevada contractors claim they properly labeled the package, but the shipping company they hired repackaged it, the contractors’ spokeswoman Tracy Bower, said in an email message. Spokesmen for Los Alamos, Oak Ridge National Laboratory, the Pantex Plant and Idaho National Laboratory declined to comment about specific shipping errors identified in internal Energy Department reports. A similar shipping and labelling error preceded the notorious radiation leak at the Waste Isolation Pilot Plant in southern New Mexico on Valentine’s Day in 2014, which exposed 21 workers to low levels of radiation and shut down the nation’s only repository for radioactive nuclear weapon waste for years. It resulted from the explosion of a drum of waste from Los Alamos that was improperly packaged and inaccurately described in the paperwork that accompanied it.

For the mistakes at Los Alamos and WIPP that led to the radioactive release, the New Mexico Environment Department imposed an unprecedented $73.25 million in fines, but the Energy Department — not Los Alamos — wound up paying it.