Steven J. Bossart
U.S. Department of Energy
D&D Focus Area
Morgantown, West Virginia

Sanjiv I. Shah, P.E.
Science Applications International Corporation
Morgantown, West Virginia

The U.S. Department of Energy (DOE) has about 7,000 surplus facilities that will eventually undergo decommissioning. A major portion of the decommissioning activities in these facilities will be dismantling and size reduction of building structures and the equipment, pipe, vessels, and other components within the buildings. Improved dismantling and size reduction technologies are needed to reduce the cost to decommission facilities and improve worker safety and productivity. In its Large-Scale Demonstration Projects (LSDP), the Decontamination and Decommissioning (D&D) Focus Area has been demonstrating and evaluating innovative dismantling technologies as part of DOE's ongoing deactivation and decommissioning efforts. For each technology demonstration, an innovative dismantling technology is demonstrated alongside the competing baseline technology, and the performance of both technologies is measured and evaluated during the demonstration. The "innovative" dismantling technologies include technologies developed by DOE or the private sector; non-nuclear commercial technologies; and technologies that have been used within the nuclear utility industry, but not DOE. The D&D Focus Area has three ongoing LSDPs at the Chicago Pile 5 Research Reactor at Argonne National Laboratory; the Plant 1 Uranium Processing Facility at the Fernald Environmental Management Project (FEMP), and the 105-C Production Reactor at the Hanford Reservation. New dismantling technologies demonstrated in the Chicago Pile 5 Test Reactor LSDP include the ROSIE mobile work platform, the dual arm work platform, the swing-reduced crane, and a remote-controlled concrete demolition system. An oxy-gasoline cutting torch was demonstrated at the FEMP Plant 1 LSDP, and a mobile work platform from EagleTech will be demonstrated in March, 1998. The LSDP at the 105-C Reactor has demonstrated a self-contained pipe cutting shears and plans to demonstrate additional dismantling technologies. In addition, the D&D Focus Area is sponsoring three demonstrations of a remote cutting technology using a Nd:YAG laser.

A major portion of decommissioning efforts in DOE's surplus facilities involves size reduction of metal components, such as vessels, pipes, conduit, and structural steel, and size reduction of concrete structures. Generally, the metal and concrete components have radioactive, organic, or heavy metal contamination, which presents worker and environmental hazards. In some cases, it is necessary to cut concrete and metal components as quickly as possible to minimize radiation dose to the workers. Baseline size reduction technologies that are currently used in DOE's decommissioning projects include mechanical saws, circular cutters, abrasive cutters, diamond wire, explosive cutting, plasma arc torch, oxy-acetylene torch, arc saw, abrasive water jet, and hydraulic shears. Backhoe rams and wrecking balls are used to dismantle large, thick concrete structures. Many of these technologies are available as both hand-held and remotely-operated tools. Each of these technologies suffers from one or more shortcomings including slow cutting speed, frequent maintenance, dust emissions, spread of contamination, generation of secondary waste, potential exposure of workers to radiation, fire hazard, limited accessibility in congested areas, noise, onerous rigging requirements, and industrial safety issues associated with working at heights.

Through its Large-Scale Demonstration Program, the Decontamination and Decommissioning Focus Area is demonstrating and evaluating innovative dismantling technologies that can potentially overcome the shortcomings of the current suite of baseline dismantling technologies. In the large-scale demonstration projects (LSDP), innovative technologies are demonstrated and evaluated alongside their respective competing baseline technologies in DOE's ongoing deactivation and decommissioning projects. Performance data collected from the demonstration of the innovative and baseline technologies will assist D&D project managers and planners in selecting the best technology for a specific application. The U.S. Army Corps of Engineers (USACE) is providing an independent and consistent cost analysis of all technologies demonstrated in LSDPs.

An Integrating Contractor (IC) Team manages each of the LSDPs. The IC Team is normally comprised of multiple, experienced D&D firms along with the site's maintenance and operating contractor (or equivalent), and sometimes universities, technology brokers, and technology firms. The IC Team screens and selects the technologies to be demonstrated in the LSDP and develops the scope of work for each baseline and innovative technology demonstration. The IC Team collects and evaluates data from each technology demonstration. The demonstration data is used by the U.S. Army Corps of Engineers to develop a consistent and independent cost analysis for each technology demonstration. This approach enables the D&D firms on the IC Team to have direct experience with the demonstrated technologies. The D&D firms are able to deploy these technologies in future D&D work within DOE, other government agencies, and commercial nuclear facilities.

Currently, the D&D Focus Area is sponsoring three LSDPs. These are the Chicago Pile 5 (CP-5) Research Reactor at Argonne National Laboratory-East, the Plant 1 Uranium Processing Facility at the Fernald Environmental Management Project (FEMP), and the 105-C Production Reactor at Hanford Reservation.

The CP-5 Research Reactor LSDP is focusing on the removal of equipment from the reactor facility and decontamination of the facility for subsequent reuse. The FEMP Plant 1 LSDP is focused on the decontamination and dismantlement of the Plant 1 complex, which is part of the former Uranium Feed Materials Production Facility. The 105 C-Reactor LSDP is an Interim Safe Storage Project, which will place the production reactor facility in a low-cost, safe-storage condition for up to 75 years pending its final disposal. Activities include demolition and removal of the 105-C building structure around the reactor block and removal of the fuel storage basin.

Seven innovative dismantlement technologies demonstrated or planned for demonstration in the LDSPs are listed in Table I. In addition, the D&D Focus Area has sponsored remote cutting demonstrations with a Nd:YAG laser on fuel storage tubes at the Energy Technology Engineering Center, on hot cell equipment in the Hanford B-Cell, and on the converter shell in the gaseous diffusion plant cells from the East Tennessee Technology Park (formerly K-25). The results or plans for each of these technology demonstrations and planned or actual deployment of the technologies are described in the remainder of the paper.

The oxy-gasoline cutting torch system from Petrogen International consists of a 2.5-gallon fuel tank with automatic flow shutoff valve, a gasoline supply hose, and a cutting torch. Pressurized oxygen is supplied from standard oxygen bottles commonly used with oxy-acetylene torches. Gasoline is delivered to the tip of the torch as a confined liquid. At the tip of the torch, the gasoline liquid expands to a vapor and is mixed with oxygen to form a combustible mixture. Mixing of gasoline vapor and oxygen in the tip of the torch eliminates back flash in the fuel line, and keeps the torch head cool.

In October, 1996, the oxy-gasoline cutting torch was demonstrated alongside the baseline technology, the oxy-acetylene cutting torch, in the FEMP Plant 1 LSDP. During the demonstration, each torch cut approximately 250 inches of metal components ranging in thickness from 0.5 to 4.5 inches. When cutting thick metal with the oxy-acetylene torch, a portion of the molten metal tended to re-fuse and clog the area of the cut. As a result, several passes were needed to completely cut through the metal. The oxy-gasoline cutting torch cut cleanly through the metal in a single pass, and did not experience re-fusing problems because the gasoline flame is 100 percent oxidizing. One demonstration showed that the oxy-gasoline torch was able to cut through a two-inch thick steel plate in 13 minutes, whereas the oxy-gasoline torch took 27 minutes to cut through the same distance on the same plate. On a four-inch thick plate, the oxy-gasoline torch cut at a rate of 50 inches per hour compared to only 10 inches per hour with an oxy-acetylene torch.

Although the price of the oxy-gasoline torch is about $500 to $600 more than an acetylene torch, it is less expensive to use because it cuts faster and uses less expensive fuel. The oxy-gasoline cutting torch uses about $3 per day of gasoline compared to $50 per day for a tank of acetylene needed for the acetylene torch. The oxy-gasoline torch system is easier to move to other job locations because its fuel tank weighs nine times less than a standard acetylene tank. On remote job sites, regular unleaded gasoline is more readily available compared to tanks of acetylene. Independent cost analysis performed by the USACE indicates that the oxy-gasoline torch cost about $0.60 per inch and the oxy-acetylene torch cost about $0.95 per inch for the range of metal components that were cut during the demonstration. Payback time to offset the higher capital cost of the oxy-gasoline torch is about 20 hours for cutting one-inch thick steel, and eight hours for cutting four-inch thick steel.

As a result of the success of the technology demonstration, Fluor Daniel Fernald, Babcock and Wilcox Nuclear Environmental Services Incorporated, Mason and Hangar at Pantex, Argonne National Laboratory, Lockheed Martin Energy Services at Oak Ridge, and Laguila (a major construction firm in New York City) have purchased and are using oxy-gasoline torches to size reduce metal components in their facilities. Over 100 torches have been purchased for dismantlement of special weapons and equipment in the former Soviet Union. Additional sales are expected from other D&D firms and DOE sites.

In April, 1998, FEMP Plant 1 LSDP plans to demonstrate a mobile work platform from EagleTech to remotely cut overhead piping and lower it to the ground. Plans are to conduct the demonstration on both indoor and outdoor overhead pipe.

The EagleTech mobile work platform uses dual telescoping manipulators. One manipulator will grasp the pipe and lower it to the ground after cutting, while the other manipulator will shear and crimp the pipe on both sides of the grasping point. The mobile work platform will be able to shear pipes up to six inches and diameter up to 30 feet above the ground or floor. The length of each section of sheared pipe is up to ten feet, and the work platform has a lift capacity of 1,000 pounds. An operator cuts the pipe using a remote control device that is either tether or radio-controlled.

The mobile work platform is expected to improve worker productivity and safety over the baseline approach of locally cutting the pipe from a scaffold or a manlift, and lowering the pipe to the ground by crane.

The self-contained cutting shears was developed by Lukas Hydraulic GmbH and Company KG. It has a built-in rechargeable battery that allows for about 15 minutes of continuous operation. A portable, external rechargeable battery can be attached to the hydraulic shears that can extend its continuous operation to about 63 minutes. The tool does not have any hydraulic fluid lines because it has a built-in accumulator that holds about one pint of hydraulic fluid. It is about 34 inches long and weighs about 50 pounds and is easily carried with the use of a sling at waist height. It can cut pipes and conduit up to 2.5 inches in diameter.

Initial demonstration of the self-contained cutting shears occurred in March, 1997 as part of the 105-C reactor LSDP. Additional demonstrations are planned for the self-contained cutting shears. The competing baseline technologies demonstrated alongside the self-contained cutting shears were a Porta-Band saw, an electric hack saw, and a hydraulic shear that are powered with 120 VAC.

The self-contained pipe cutting shears was effective in cutting pipes up to 2.5 inches in diameter, but did not cut through three-inch diameter pipes. It was able to make over 100 cuts before needing a blade change or battery recharge. The production rate for cutting two-inch diameter pipe was about 17 feet per hour. Production rates for the competing baseline technologies ranged from 10 to 17 feet per hour. Both of these production rates were calculated based for cutting 2.5 in diameter Schedule 80 steel pipes in 8 ft. sections.

Cost analyses from the USACE indicates that the self-contained cutting shears is less expensive to operate for cutting one-inch and two-inch pipes than the competing baseline technologies. The cost for cutting two-inch pipe into fifteen foot sections using the self-contained cutting shears was $5.70 per foot compared to $5.95 per foot for the hydraulic shear, $7.24 per foot for the Porta-band saw, and $12.90 per foot for the electric hack saw. The capital cost of the battery-operated shears is about $8,000 to $12,000 depending on supplier, and recommended replacement parts include a backup battery, battery charger, and cutting blades.

A Brokk 150 concrete demolition system resembles a small Bobcat vehicle with a remotely-controlled articulated hydraulic boom. A variety of decommissioning tools can be attached to the end of the 15-foot boom including a hydraulic hammer, an excavating bucket, a concrete crusher, and a hydraulic cutting shear. The operator can remotely control the Brokk system at distances up to 400 feet. The Brokk system requires 480 volt and a 50 amp circuit for power.

The Brokk system was demonstrated as part of the ongoing decommissioning project at the Janus Research Reactor at Argonne National Laboratory. During the demonstration, the Brokk 150 system dismantled about 66 cubic yards of the biological shield wall and the reactor pedestal which are made from reinforced concrete. In 16 days, the Brokk 150 system was able to dismantle the biological shield wall and reactor pedestal with the hydraulic hammer and load it into waste containers with the excavating bucket. This work was projected to take six months to complete with manual jackhammers.

Cost analysis by USACE showed that the Brokk system cost about $17 per cubic foot of removed concrete compared to manual jackhammer at about $255 per cubic foot. The production rate for the Brokk system was about 12 cubic feet per hour compared to only 0.6 cubic feet per hour for manual jackhammering.

The dual arm work platform (DAWP) is a remotely-operated deployment platform that uses a variety of end effectors to dismantle equipment and components. Two Schilling Titan III manipulator arms provide six degrees-of-freedom and are powered by a 3000 psi hydraulic system. Each arm is capable of lifting 240 pounds while the grippers on the end of the arms can exert 1,000 pounds of crushing force and a rotational torque of 75 foot-pounds. The platform holding the two arms is designed to be free standing or suspended from an overhead crane. End effectors range from crow bars to sophisticated saws. Components for the dual arm work platform were purchased from or provided by Oak Ridge National Laboratory, Idaho National Engineering and Environmental Laboratory, RedZone Robotics, and Schilling Robotics Systems.

During demonstration at the CP-5 Research Reactor Large-Scale Demonstration Project, the DAWP remotely cut and dismantled the aluminum reactor tank; disassembled the boral, steel, and aluminum subassemblies, and transferred these materials to a staging area. It removed 5,300 pounds of graphite blocks; 1,400 pounds of lead sheets; 620 pounds of boral; 2,000 pounds of carbon steel; 26 carbon steel studs; and 600 pounds of aluminum plate. Approximately 200 linear feet of aluminum plate up to 3/4-inch thick was cut with the DAWP. Two operators controlled the DAWP from a control room to maintain a safe distance from the radiation in the CP-5 research reactor. The DAWP operated in radiation field between 0.75 and 2 R/hour during the demonstration. It is estimated that remote operation of the DAWP saved at least 15 person-rem of exposure that workers would have been exposed by conducting the same work with long handle tools.

Capital cost for the DAWP is estimated at $1.2 million. Cost analysis based on the demonstration in the CP-5 LSDP indicates that the DAWP is cost-competitive compared to the baseline technology using workers with long handle tools to perform the same work. For example, the DAWP cut the reactor tank at a rate of 3 ft per hour or $108 per foot compared to manual cutting of the reactor at a rate of 2.7 ft per hour or $154 per foot. The unit costs for DAWP assume a life of 20 years and an annual maintenance cost of $10,000.

Facility and equipment dismantlement can benefit from the use of existing overhead cranes. Cranes can be used to lift loads and to deploy remotely-operated equipment to dismantle and size reduce structures and equipment. A natural pendulum-like swing is induced to suspended loads from movement of an overhead crane. DOE's Robotics Technology Development Program funded the upgrade of an existing overhead polar crane at CP-5 research reactor and installation of Convolve's No-Sway Control System to reduce its pendulum-like swing. The No-Sway Crane Control System is a digital control system that adjusts the bridge and trolley motion of the crane to limit the induced swing in the load. Additional features added to the crane include a radio-control system for remote operation of the crane; a motorized rotating block; an on-board, remotely-operated camera; and load cells with remote load displays.

During the demonstration, the swing-reduced crane was used to place the Dual Arm Work Platform in the reactor and for lifting other loads. Comparative measurements on using the crane with and without swing-reduced control indicated a reduction in the induced swing by 61 to 86%. Remote operation of the crane with swing-reduced control improves the efficiency of moving loads and size reducing materials, increases worker productivity, reduces cost, and reduces worker exposure to radiation. In intermittent use typical of D&D operations, the cost savings associated with use of a swing-reduced crane is not significant, but its main advantage is improvement in worker safety. For waste management operations with continuous and repetitive movements, the use of a swing-reduced crane could result in substantial savings.

ROSIE evolved from a Remote Work Vehicle that was developed and built by Carnegie Mellon University (CMU) to support cleanup work at the Three Mile Island nuclear accident site. Lessons learned from the Remote Operated Vehicle were incorporated into the design of ROSIE. It is a remotely-operated, mobile and versatile work platform that was designed and built by RedZone Robotics in conjunction with CMU. It is a four-wheel drive, four-wheel steer locomotor that is capable of deploying tools weighing up to 2,000 pounds from the floor to 27 feet above the floor by use of a telescoping boom with various end effectors. ROSIE weighs about 14,500 pounds and has a footprint of 80 inches by 114 inches. Tethered power requires a 480 volt, 90 amp source. A control console allows a single operator to remotely manipulate ROSIE using video and data displays. Video displays are provided by up to ten cameras mounted on ROSIE in addition to cameras mounted in the facility.

During the demonstration at the Chicago Pile 5 Research Reactor, ROSIE was fitted with a jackhammer and removed high-density concrete from the reactor's upper shield plug in about 45 minutes. It removed about one-third of the concrete that manual operation with a jackhammer can remove in about two weeks. ROSIE was used to further size reduce reactor components after the DAWP has cut and removed them from the interior of the reactor. It was used to move the reactor components into waste containers. In some instances, ROSIE was used as a camera boom to support operation of the DAWP. ROSIE is an enabling technology for work in high radiation areas that would prohibit people from entering the area.

During the demonstration, ROSIE was operated in a radiation field ranging 0.05 to 2.0 R/hr using a single operator from a remote control room. Use of ROSIE reduced personnel exposure by about 2 person-rem compared to manual dismantlement of the reactor with long handle tools. The capital cost of ROSIE with tooling is estimated to be in excess of $1.2 million.

The Energy Technology Engineering Center (ETEC) coupled a laser and fiber optic system to deliver the laser beam to remotely size reduce contaminated fuel storage tubes. ETEC has remotely size reduced about 300 fuel storage tubes using a Lumonics 2-kW neodymium-doped yttrium aluminum garnet (Nd:YAG) laser. The laser was configured to operate in a continuous wave mode at a power of 0.8 kilowatts. The ten-foot long, five-inch diameter, 16-gauge steel tubes were cut longitudinally and circumferentially into four pieces. All sides of each of these pieces can be thoroughly inspected and decontaminated, if necessary, to free release the metal. Typical cutting rate was about 120 inches per minute. Key benefits compared to baseline cutting technologies include faster cutting rate, smaller kerfs to reduce secondary waste, and remote beam delivery.

ETEC transferred its Lumonics 2-kW Nd:YAG laser with fiber optic delivery cable to Manufacturing Sciences Corporation (MSC) to remotely cut radioactively-contaminated converter shells from the former K-25 Gaseous Diffusion Plant (GDP) site. Other components of the MSC system are a Cincinnati Milacron robot, an automatic turning roll, a light-proof enclosure, and a programmable logic controller. The six-foot diameter converter shells are nominally 1/2-inch thick and consist of nickel-plated carbon steel. The converter shells were successfully cut at a rate of 30 inches per minute using 1,800 watts of laser power with oxygen assist gas. MSC also cut one-inch thick carbon steel at a rate of 3 inches per minutes using 1,900 watts of laser power. As a subcontractor to BNFL, MSC is considering using the Nd:YAG laser to size reduce, decontaminate, and dispose or recycle over 126,000 tons of metal and over 1,500 converter shells from the K-29, K-31, and K-33 buildings at the former K-25 GDP site.

Pacific Northwest National Laboratory is demonstrating a Lumonics 2-kW Nd:YAG laser to size reduce components in high-radiation environments. Specifically, the demonstration focused on size reduction of several chemical processing racks in the B-Hot Cell in Building 324 at the Hanford Reservation. The project has used commercial saws, hydraulic shears, plasma torch, and water knife to size reduce equipment in the hot cell, but each of these technologies has drawbacks including slow cutting speed, secondary waste generation, and limited versatility to multiple metals and geometries. Results from the demonstration indicate that the laser cutting is about 10% less expensive than the plasma cutting torch on unit cost basis. In comparison to the plasma cutting torch, the laser would serve as a better technology where smoke generation, secondary waste generation, dirty or grout covered materials or difficult geometries are the main challenges.

Through its Large-Scale Demonstration Projects and other projects, the D&D Focus Area is demonstrating innovative dismantlement technologies with superior performance over baseline dismantlement technologies. Several of the innovative dismantlement technologies have been implemented once or deployed multiple times in DOE's deactivation and decommissioning projects following a successful demonstration. These technologies include the Dual Arm Work Platform, the Swing-Reduced Crane, Rosie Mobile Work Station, and the Oxy-gasoline Torch. Through implementation and deployment of these innovative dismantlement technologies in DOE's deactivation and decommissioning projects, D&D planners and workers are advancing the state-of-the-art for dismantling technologies, while achieving cost savings and other benefits of the innovative dismantling technologies. In essence, the innovative dismantling technologies that have been deployed in DOE's deactivation and decommissioning projects are setting a higher performance standard as the new baseline dismantling technologies.

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Draft Innovative Technology Summary Report, Self-Contained Pipe Cutting Shears, 105-C Reactor Interim Safe Storage Large-Scale Demonstration Project

Draft Innovative Technology Summary Report,, Remote Controlled Concrete Demolition System, CP-5 Large-Scale Demonstration Project

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Draft Innovative Technology Summary Report, ROSIE: Mobile Teleoperated Robot Worksystem, CP-5 Large-Scale Demonstration Project

Decontamination and Decommissioning Focus Area, Quarterly Report - October, 1997; Covering July-September, 1997, p. 27, 29, 31.

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