A gauge that measures liquid levels inside processing equipment at a bottling plant in Greendale, Indiana, has turned up empty. The sealed radioactive source that was supposed to be sitting inside it is gone, no paperwork shows where it went, and the company that owned it has spent more than a week searching without an answer.
What Turned Up Missing at the Greendale Plant
The facility, operated by Refresco Beverage Inc., discovered the problem during a routine physical inventory of its licensed radioactive materials on August 28, 2026. Workers found the housing for a Filltech model FT-50 level gauge, serial number 115319, but the sealed source inside it, a 100-millicurie unit of americium-241, was not there. The empty casing was still inside the facility; the source that belongs in it was not.
Level gauges like the FT-50 are common in food and beverage manufacturing. They use a small sealed radioactive source mounted on one side of a tank or pipe and a detector on the opposite side to measure how full a vessel is without anyone having to open it up, which matters in a bottling line where hygiene and continuous operation both count. Americium-241 is the same isotope used in trace amounts inside household smoke detectors, but the quantity in an industrial gauge like this one is far larger and is regulated accordingly. Manufacturers favor the isotope for these devices because it emits gamma radiation at an energy level that is easy to detect through steel or plastic tank walls while still having a long enough half-life, about 432 years, that a single sealed source can stay in service for decades without needing to be replaced.
That combination of properties is also what makes a missing source a genuine regulatory concern rather than a paperwork footnote. A sealed source designed to last decades does not simply wear out or degrade to nothing; if it left the Greendale plant intact, it is presumably still intact somewhere else, whether that means sitting unnoticed in a scrap pile, a landfill, or in the hands of someone who has no idea what they are holding.
No Transfer Records to Explain the Gap
Companies that hold licensed radioactive material are required to keep records every time a sealed source is moved, serviced, transferred to another company, or disposed of. In this case, Refresco has told the Nuclear Regulatory Commission that no such records exist for this particular source. There is no paper trail showing it was sent out for calibration, returned to the manufacturer, or handed off to a waste disposal contractor. The company says its search for the source is continuing, but as of the filing, it had not been located.
Why the NRC Treats This as a Reportable Loss
The missing source was reported to the NRC under 10 CFR 20.2201, the federal rule that requires licensees to notify the commission within 30 days when licensed material above certain quantity thresholds is lost or cannot be accounted for, in this case a source lost or stolen at more than 1,000 times the exempt possession quantity. The filing is logged as NRC Event Number 58433 in the agency’s event-status reporting system, the same public database used to track everything from equipment malfunctions at nuclear power plants to lost industrial gauges like this one.
A 100-millicurie americium-241 source is not powerful enough to pose the kind of danger associated with a reactor accident, but it is not something regulators treat casually either. Sealed sources of this size can deliver a meaningful radiation dose to someone who handles the source directly or keeps it in close proximity for an extended period, particularly if the sealed capsule is damaged and the material inside is no longer contained. That is why the NRC’s lost-source reporting threshold exists, and why a missing gauge source, however it happened, triggers a formal investigation rather than a shrug.
The NRC logs every such notification in its Nuclear Material Events Database, a public record maintained jointly with the states that regulate radioactive material under agreements with the federal government. Entries range from minor administrative slips, such as a source found a few feet from where inventory records said it should be, to genuine losses where a sealed source is never recovered. Each entry gets a sequential event number, which is how this case became NRC Event 58433, and each stays open until the licensee either accounts for the material or the agency closes the file after concluding it cannot reasonably be found.
How Sources Like This Usually Go Missing
Missing or orphaned radioactive sources are not new to industrial settings. The NRC’s own guidance on lost and stolen material notes that most cases trace back to breakdowns in routine handling rather than theft: a gauge scrapped along with old equipment without anyone checking it first, a source sent to a metal recycler by mistake, or records simply not updated when a device changed hands inside a large company. Investigators working the Greendale case will likely start by retracing the gauge’s service history, checking whether it was ever sent out for maintenance, and confirming whether it might have been scrapped along with other decommissioned equipment rather than deliberately removed.
What Happens While the Search Continues
Refresco remains the licensee of record and is responsible for locating the source or accounting for its final disposition, whether that means it turns up misplaced somewhere on the property, was inadvertently discarded, or was transferred without documentation to another party. The NRC’s event report will be updated as the investigation develops, and the agency can pursue enforcement action separate from the safety question if it determines the licensee’s recordkeeping fell short of federal requirements. For now, the gauge housing sits empty, the source is unaccounted for, and the only new development is that the case is now part of the public record.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
More from Morning Overview
- Card skimmers hidden on gas pumps and ATMs are draining accounts, and here’s the tell
- The FBI says hackers are hijacking outdated home routers, and it named the models to check
- Older Teslas are wearing out in ways early owners never saw coming
- A common childhood virus is now tied to multiple sclerosis years later
