Put aside the saws and blowtorches. Sometimes deactivation and decommissioning work can actually be graceful. Bright light flashes and sparks fly when a laser tool is used to cut through a contaminated glovebox. The fireworks are directed by a large robotic arm that holds the laser-focusing head and seems to glide along the surface of the box, effortlessly slicing the thick metal into manageable pieces.

Size reduction of radioactively contaminated gloveboxes is just one use for a new remotely operated, programmable laser cutting system. Called the transportable oversized waste reduction system (TOWRS), it is different from previous laser cutting projects in that it combines the well-known benefits of laser cutting technology with the versatility of programmable robotics. The result is improved efficiency and utility through flexible automation.

“It cuts stainless steel just like a knife through butter,” said Edward H. Hohman, a technology developer and potential future end user with Bechtel Nevada. “It is fast, and most importantly to us, it can be operated remotely.”

Initial deployment of TOWRS, funded through the Accelerated Site Technology Deployment (ASTD) initiative, is planned at Los Alamos National Laboratory’s (LANL) Decontamination and Volume Reduction System (DVRS) building site in early 2002. There TOWRS will size reduce and decontaminate oversize metallic waste items. The off-the-shelf, industrial 1.5-kW Nd/YAG laser is used to cut large contaminated metal items into pieces small enough for packaging in standard shipping containers. Most of the waste is transuranic (TRU), contaminated with low levels of radioactive isotopes from weapons production processes. Because of its size, this waste material cannot be shipped, stored, or treated at existing facilities.

Some of the oversized waste that may be headed for LANL’s DVRS is temporarily stored in 58 shipping containers at the Nevada Test Site. These containers, some as long as 13 feet, are filled with bulky, TRU-contaminated objects like gloveboxes, equipment racks, lengths of metal piping, and even a metal desk. These containers and their contents need to be size reduced at an off-site DOE facility so the waste can be certified and shipped to the Waste Isolation Pilot Plant.

The versatility and precision of the system allows the technology to address a variety of waste objects and also accurately remove high-contamination areas, or “hot spots,” from otherwise low-level waste items. Such selective size-reduction capability promises to save significant amounts of money, since low-level waste items cost $3,000 per cubic meter to dispose of, as compared to $50,000 for TRU waste.

“We developed the industrial laser configured with robots to create a flexible work cell,” said Ross Muenchausen, principal investigator for the TOWRS ASTD project at LANL. “We’ll be able to process waste not only faster, but also more intelligently.”

The system actually utilizes two robotic arms, one to guide the laser and the other to handle the cut pieces. Both robot arms and the laser are remotely controllable from a self-contained trailer, where an operator uses a control panel with computer monitors, connected to cameras mounted within the containment structure. The high-power laser output from the trailer is connected by fiber-optic cable to the cutting head mounted on the robot, thus minimizing exposure of workers to potentially hazardous laser radiation. This trailer is also transportable, so the TOWRS laser system can be deployed at multiple DOE sites with minimal capital costs.

The computer-driven laser system is quick and easy to set up. During operations on a typical glovebox, it is capable of slicing along its preprogrammed path at more than 7 feet of metal per minute, compared to inches per minute for traditional manual size-reduction tools, such as reciprocating saws, nibblers, and handheld torches. The TOWRS laser cutting tool is expected to reduce the average time required to size reduce a contaminated glovebox from one week to less than one day.

TOWRS is as safe as it is fast. Remote operation minimizes the need for workers to be exposed to contaminated environments and industrial-type accidents. TOWRS laser cutting also generates less fumes and secondary waste than the plasma torch. Terry Lucke, a project engineer from Fluor Hanford in Richland, Washington, said, “It’s a very clean operation.” Operators also do not have to worry about using cumbersome manual cutting tools while dressed in protective equipment. That slow, tedious method is inefficient and subjects the worker to hazards such as puncture wounds and repetitive motion injuries. TOWRS operates with much less risk. “By deploying TOWRS, you’re going to essentially eliminate worker fatigue and inhalation exposure during the cutting operation,” Muenchausen added.

The system was designed and constructed by a team from Fluor Hanford and LANL, while Bechtel Nevada is providing overall project management. Project staff are currently developing operating procedures, performance testing the integrated system at the vendor’s (GSI Lumonics) facility, and analyzing cost savings.

During the planned deployment at LANL, TOWRS will assist in the size reduction of hundreds of oversize TRU waste boxes. TOWRS will likely be used at Hanford to remove stainless steel cell liners and perhaps for similar oversized waste at Rocky Flats. Depending on the availability of future funding for TOWRS deployment, this laser may be called on to process the abundance of material that exists throughout the DOE complex.

The future looks bright for the TOWRS traveling laser show.

For more information, visit http://www-emtd.lanl.gov/laser/cutting.html or contact Ross Muenchausen, LANL, (505) 667-0391, rossm@lanl.gov.