America's secrets mishandled at California lab guarding nuclear arsenal in alarming security lapse

A California laboratory that helps safeguard America’s nuclear arsenal was found to have mishandled classified information, federal officials have revealed.

One of the security failures received the Energy Department’s highest severity rating, reserved for cases involving actual harm or a high potential for harm to national security.

The National Nuclear Security Administration issued a preliminary notice this month detailing failures at the Special Technologies Laboratory in Santa Barbara, where sensitive information was processed on computer systems not approved to handle it.

Classified material requires specially approved systems designed to restrict who can see it and how it can be shared.

Using unapproved systems can increase the risk of government secrets reaching people without permission.

Officials have not disclosed what information was involved or confirmed whether anyone accessed it without authorization.

The laboratory develops technology to help keep America’s nuclear weapons reliable and detect foreign nuclear weapons programs, placing its work at the heart of the country’s defenses.

The laboratory’s operator, Mission Support and Test Services, faces a proposed $196,350 penalty.

The National Nuclear Security Administration (NNSA) issued a report this month, detailing how sensitive material was processed on computer systems not approved to handle it, putting government secrets at risk (stock)

The Special Technologies Laboratory is a vital research and development hub that operates as a specialized, multi-mission satellite facility under the Nevada National Security Sites (NNSS), which is funded and overseen by the NNSA.

NNSA is a semi-autonomous agency within the DOE, responsible for enhancing US national security through the military and scientific application of nuclear energy.

The Special Technologies Laboratory develops advanced testing and measurement tools to help ensure America’s nuclear weapons remain reliable.

It also combines sensors with artificial intelligence to spot unusual activity and help protect critical infrastructure from threats.

NNSA said the proposed penalty takes into account corrective actions intended to prevent such incidents from happening again.

However, its public summary does not explain what changes were made to protect classified information.

MSTS can challenge the findings or seek a reduction in the proposed penalty. Federal rules generally give the company 30 days from receiving the notice to submit its response, although that deadline can be extended.

An earlier federal letter reveals that the security incident at the California laboratory was discovered in March 2024, well before the newly announced proposed penalty.

The Special Technologies Laboratory is a vital research and development hub that operates as a specialized, multi-mission satellite facility under the Nevada National Security Sites (pictured)

MSTS recorded the incident as closed in the Energy Department’s security reporting system on August 5, 2024.

It subsequently reported the closure to the department’s intelligence and counterintelligence office in February 2025.

Federal investigators conducted a fact-finding review at the Santa Barbara facility from June 10 to 12, 2025.

In a September 10 letter notifying the company of a formal investigation, officials said the inquiry would examine how classified information had been processed on computer systems that were not approved to handle it.

Investigators also left open the possibility of examining wider failures to comply with rules protecting government secrets.

The department said it would review documents collected before and during the fact-finding visit, adding that further visits or interviews with employees were unnecessary.

The Daily Mail has contacted the US Department of Energy (DOE), NNSA and the Special Technologies Laboratory for .