A former Los Alamos National Laboratory employee who was fired this summer for erroneously shipping weapons-grade plutonium by air instead of by ground as required by federal regulations is suing the lab’s management for breach of contract.

Juan Montoya claims he was made a scapegoat for “root cause systemic failures in processes, procedures, supervision, resources [and] training” that belong to Los Alamos National Security LLC, or LANS.

Montoya’s state District Court suit accuses LANS of “failing to provide adequate management presence, supervision, training, procedures, resources and safeguards relating to the shipment of radioactive materials at issue,” among other claims.

Efforts to reach Montoya for comment were unsuccessful Wednesday.

His attorney, Timothy Butler, said in email, “Mr. Montoya brings this lawsuit alleging he is the proverbial ‘head on the post’ — having been made a scapegoat for LANS’ failure to protect all of us by assuring safe shipping of highly radioactive materials.”

In July, a few days after he was fired, Montoya told The New Mexican the shipment error involving 100 grams of plutonium was “a mistake that could have happened to anybody.”

The incident, though, followed a series of safety problems at the lab, including a fire in the plutonium facility as a result of an unlabeled container and the shipment of mislabeled hazardous waste to a facility near Denver.

Montoya had worked at the lab for 15 years before he was fired.

“At all times during his employment at LANS, until his involuntary termination, Montoya received good performance reviews, was never subject to any disciplinary actions, and had no security infractions,” the lawsuit states.

As part of his duties, Montoya shipped radioactive and hazardous materials. He had about three years’ experience and three days of training specifically related to shipping radioactive and hazardous materials, the lawsuit states.

Along with his duties, Montoya, who had the most seniority at the lab’s SM-30 Main Warehouse, was also “training and supervising three co-workers as they learned the shipping processes at the busy” facility, the lawsuit states.

“Montoya had spoken with his supervisors on many occasions that he was short-staffed and needed help with the [quality review] and shipping process,” the lawsuit states. “No action had been taken.”

In the complaint, Montoya admits making a mistake by shipping the plutonium by air to two other laboratories in the nation’s nuclear weapons network of facilities. Though the shipments arrived safely, air shipments of plutonium pose a greater threat of radioactive release because of air pressure, the possibility of a crash that would be severe enough to cause a release and other factors.

“All his previous plutonium shipments had been Type A plutonium, which can go by either air or ground. These particular shipments were Type B fissile plutonium shipments that were required to go only by ground,” the lawsuit states. “Montoya mistakenly checked off that the shipments would be going by air.”

Though Montoya sent the shipping information to others, including the lab’s Emergency Response Team and FedEx, no one else caught the mistake. Montoya contends that others, including Nestor Trujillo of the lab’s TA-55 plutonium facility and Lawrence Livermore National Laboratory in California, knew or should have known about the shipment error.

“Trujillo stated to Montoya that the customer at Lawrence Livermore was upset with LANS management and this customer was out to prove a point that LANS had been making many crucial similar mistakes in the last five years,” the lawsuit states.

The lab denied that Montoya was singled out over the incident.

“Los Alamos National Security (LANS) held accountable those involved from the individual contributor level up the management chain through actions that included terminations, suspensions and compensation consequences,” lab spokesman Matt Nerzig said in an email.

As a result of the shipping error, Nerzig said “the responsibility for fissile nuclear material shipments has been transferred to a different organization within the laboratory.”

Montoya is asking for, among other things, unspecified compensatory and punitive damages.

Follow Daniel J. Chacón on Twitter @danieljchacon.