Caltrans' Transportation Laboratory, which houses the agency's radiation-based testing equipment, was cited by the California Department of Public Health in October for numerous radiation handling and training violations.
Many of the transgressions, according to documents released to The Bee late last month, had gone on for years and involved devices used to test concrete in the foundations of some freeway structures. The test meters, called gamma-gamma loggers, also were implicated in problems reported by The Bee last year in which a former state technician falsified data.
Work with the devices, stored and maintained in the "TransLab" on Folsom Boulevard near California State University, Sacramento, was halted from Oct. 3 to Oct. 19 while Caltrans corrected the deficiencies. The fixes were approved by radiation-health officials.
The violations involved failures to "develop, document and implement a radiation protection program" for the gamma-gamma loggers, which contain cesium 137, a substance that emits hazardous gamma rays for decades.
No evidence of harm to workers was found.
"The risk of exposure to workers was less than a normal X-ray" and no unusual exposures were recorded, said Department of Public Health spokeswoman Anita Gore. "There was no public health risk determined in the (department's) inspection."
Cesium 137 is widely used in industrial and medical settings. It has received special attention as a possible ingredient for a terrorist weapon designed to disperse radioactive materials over a wide area but lacking the explosive force of a nuclear weapon.
The inspection was launched after a confidential source reported training lapses to the Department of Public Health, Gore said.
But Will Shuck, Caltrans deputy director for external affairs, said the inspection stemmed from a licensing mistake misidentification of the test devices detected by "federal officials who were examining our testing program."
While not in use, the test instruments were locked within lead shielding and "posed no health risk," Shuck said.
Department of Public Health officials also cited Caltrans for errors involving shipping and transporting the test equipment over public roadways, for training inadequacies and for failing to calibrate and properly maintain the devices since 2007.
The citation did not address 2009 allegations by a whistle-blower who said that Duane Wiles, the technician who admitted to falsifying data, might routinely have violated safety rules by storing test devices in a vehicle parked outside his Sacramento residence and by holding onto nuclear devices for extended periods without apparent work-related justification.
In general, handling of the test meters "was thoroughly addressed," said Gore, "by ensuring that proper health and safety training was performed and procedures were in place."
Asked if Caltrans followed up on the allegations about Wiles, Shuck said, "(T)he whistle-blower provided information that helped us improve our operations."
Wiles was fired by Caltrans after The Bee reported on his activities last fall, but on appeal he was allowed to retire with full benefits.