The Technical Division’s Cavity Processing R&D Group recently built, from the ground up, a state-of-the-art facility at Fermilab for electropolishing accelerator cavities. The group’s ingenuity in incorporating the facility’s safety features has garnered them Fermilab’s 2012 Industrial Hygiene Award.
ESH&Q Industrial Hygiene Subcommittee Chair David Baird presented the group, led by Lance Cooley and Charlie Cooper, with the award on Oct. 18.
“What was so impressive about their project was that they built environmental, health and safety elements into every step of the process,” Baird said.
It was no small feat considering that researchers using the electropolishing facility, housed in the Cavity Processing Research Laboratory in Industrial Building 4, will deal with some particularly nasty chemicals to polish accelerator cavities — metal structures that provide an increasingly energetic path down which particles travel. Electropolishing is the standard cavity-polishing method, one that involves an acid, such as hydrofluoric acid, to smooth cavities’ inner surfaces. The process requires expertise well outside particle physics.
“Fermilab is not a chemistry or materials lab, and that meant that we had to create as much as we had to copy existing best practices,” Cooley said. “Both of those aspects defined the challenge of building this facility.”
As little as 30 parts per million of the vapor from hydrofluoric acid is considered to be immediately dangerous to life and health, and mere contact with skin can cause chemical burns and potential systemic poisoning. Unlike other acids, hydrofluoric acid does not cause an immediate burning sensation to alert the victim, so exposure can go unnoticed for a long time.
The facility minimizes risk at every level. The electropolishing room is functionally isolated from the rest of the building and under constant negative pressure. Controls are fully automated so operators never come close to acid, and interlocked safety systems can shut down operations if acid is detected by sensors. The polishing tool itself is housed in a specially designed enclosure. All exhaust air from the enclosure goes through a scrubber, and all rinse water from the etching process goes through a neutralization unit. Spent acid is automatically transferred to approved double-layer containers. Even in the unlikely event of a spill, a special containment system allows responders to recover acid and neutralize the wash-down completely within the facility.
Further, access to the facility is strictly controlled, and authorized employees undergo extensive training.
Cooley noted that Lead Engineer Cooper fit the design into existing building space and that the polishing tool and computer control system were built from scratch by talented staff.
“It’s our research facility — home-grown,” Cooley said.
Fermilab’s Industrial Hygiene Award is given annually to a Fermilab employee or group whose efforts have resulted in substantial progress to Fermilab’s Industrial Hygiene program, which is concerned with the control of occupational health hazards that arise as a result of or during work.
“When you see staff working to limit the potential for exposure from design to construction to operation — that’s what we all aspire to,” Baird said.