MIXED WASTE HANDLING AND SEGREGATING SYSTEM FOR 55-GALLON WASTE DRUMS

Marcela R. Stacey, Kevin C. Croft, David Pace, Derek Wadsworth and Miles Walton
Idaho National Engineering Laboratory
Robotics Technology Development Program
U.S. DOE Mixed Waste Focus Area

ABSTRACT

An automated system is being developed within the US Department Of Energy to prepare 55 gallon drums of mixed low-level and mixed transuranic waste for transport from DOE sites to a disposal facility. This system provides for the reclassification, treatment, and final disposition of stored mixed waste drums. The system has application to sites requiring equipment to perform similar tasks and will be evaluated and improved as it is used.

The Handling and Segregating System for 55-gallon drums, (HANDSS-55), is composed of three main subsystems, an integrated control system, and other support subsystems. The first subsystem is a non-destructive drum opening/closing system that provides access to the contents of a drum. The second subsystem is a drum liner transfer system that extracts liners from corroded or otherwise damaged drums, and places them in DOT acceptable drums. The third subsystem is a selective waste removal system that is able to remove selected non-compliant waste items from a drum so that it can be reclassified as acceptable for transport. The three subsystems are controlled by an integrated control system that provides a high level of automation and a consistent operator interface. The support subsystems provide containment and access to the main subsystems and handling for process wastes.

The design of this system is being developed under the direction of the Robotics Technology Development Program (RTDP) in conjunction with the Mixed Waste Focus Area Program. The effort is coordinated by the Idaho National Engineering Laboratory and supported by Savannah River Technologies Center, Sandia National Laboratory, Los Alamos National Laboratory, and a users' group formed with representatives from the various DOE sites that reported a need for the technology at their sites.

BACKGROUND

The U.S. Department of Energy (DOE) Office of Science and Technology (EM-50) is developing technology to assist the DOE complex treat their mixed wastes. A survey of facilities in the DOE revealed multiple needs that could be addressed with robotics and automation technologies. In particular, the Idaho National Engineering Laboratory (INEL) is party to the Idaho Settlement Agreement between the DOE and the State of Idaho. This agreement states that at least 15,000 drums of waste will be removed from the INEL by the year 2002. Currently, there are approximately 129,000 drums stored at the INEL with waste that potentially can be transported to the Waste Isolation Pilot Plant (WIPP). Much of this waste has been stored in 55-gallon drums for many years, with the drums experiencing varying degrees of degradation. It is apparent that a significant percentage of these drums can not be shipped in their current condition. The INEL drums also contain items that are not acceptable under the current WIPP Waste Acceptance Criteria (WAC) that must be removed prior to shipment.

After careful consideration of the DOE complex needs, and the INEL's needs to meet the Idaho Settlement Agreement, a development effort, the Mixed Waste Handling and Segregation System for 55-Gallon Waste Drums (HANDSS-55), was started to create a system to provide acceptable waste drums for transport to WIPP. The identified functions of the system are to open and close waste drums non-destructively, to transfer drum liners and contents from unacceptable drums to acceptable drums, and to remove items from drums that are not acceptable for disposal under the current WIPP WAC.

HANDSS-55 is a collaborative effort between INEL, Savannah River Technologies Center (SRTC), Sandia National Laboratory (SNL), Los Alamos National Laboratory (LANL), and a Users Group formed with representatives from the various DOE sites.

Currently, the DOE does not own an integrated handling and segregating system such as described above. There have been previous systems developed that address specific portions of the main subsystems, yet a complete integrated system does not currently exist. During 1994, SRTC demonstrated a full-scale prototype that included much of the functionality of HANDSS-55. This SRTC prototype also demonstrated a large number of other functionalities that HANDSS-55 does not offer under the current work scope. The HANDSS-55 is a newly developed integrated system using some previously developed technologies, not a modification of an existing system.

During Fiscal Year 1997, development will focus on handling 55-gallon drums. The reason for this seemingly narrow scope is that the TRUPACT II transporter is the only transporter that has been certified by the U.S. Department of Transportation (DOT) to transport mixed transuranic waste (MTRU) and mixed low level waste (MLLW) over U.S. public highways. The TRUPACT II was designed to operate at highest packaging efficiency when transporting fourteen 55-gallon drums per shipment. Two other supporting reasons for focusing on 55-gallon drums are: 1) the largest percentage of the waste across the DOE complex is already stored in 55-gallon drums, and 2) the non-intrusive characterization technologies at the INEL site are strictly limited to handling 55-gallon drums.

Another optional packaging configuration for the TRUPACT II is a set of four overpacked 83-gallon drums in TRUPACT II Standard Waste Boxes (SWBs). In this optional configuration, a non DOT-acceptable 55-gallon drum is packed in a DOT-acceptable 83-gallon drum. Unfortunately, the packaging efficiency is greatly reduced and renders the 83-gallon drum overpack configuration expensive, lengthy, and impractical for transferring large amounts of waste.

TRUPACT II SWBs have also been designed to transport bulk waste, however, these boxes are very expensive and less efficient than 55-gallon drums. Another challenge with the SWBs is that the drums contents, that were likely sorted originally, would become all mixed again if the SWBs are filled in "bulk mode."

SYSTEM OVERVIEW

The HANDSS-55 will consist of three main subsystems:

• a Non-Destructive Drum Open and Closing subsystem (NDDOC)
• a Material Movement and Liner Transfer subsystem (MM&LT)
• a Suspect Material Removal subsystem (SUMR)

These three subsystems will be fully integrated by an overall control system. Other support subsystems are also an integral part of the HANDSS-55. They include a Process Waste Reduction (PWR) subsystem, Destructive Drum and Liner Opening subsystem (DD&LO), material handling equipment, an overpacking station, glove ports, and etc.

The HANDSS-55 handles 55-gallon drums and is designed to operate inside a glovebox built for each end user. The HANDSS-55 system is capable of handling and processing drums of MLLW and/or MTRU waste that contain items not acceptable at WIPP, and/or drums that have degraded and are not certifiable for transportation. Originally, the HANDSS-55 was to be designed as a portable system/facility, however, further consideration and evaluation of this requirement indicated that the HANDSS-55 be a modular architecture operating in a fixed facility. Throughput requirements are calculated to meet the Idaho Settlement Agreement and used to generate specific throughput requirements for the individual subsystems.

Figure 1 shows a schematic view of the HANDSS-55 system layout. A receiving station receives the drums. At this station, identification and inventory information are cataloged and tracked as well as any other information needed to determine the process route for each drum. A process flow diagram has been developed that details actions and material movements through the system. Three basic scenarios are considered: DOT acceptable drums with WIPP non-compliant items inside; DOT non-acceptable drums, with or without WIPP non-compliant items inside; and overpacked DOT non-acceptable drums with or without WIPP non-compliant items inside. The output of the system are DOT acceptable drums that meet WIPP acceptance criteria. Debris generated during the processing are packaged as acceptable drums. WIPP non-compliant items that are removed from drums are directed to other appropriate waste streams.

MAIN SUBSYSTEMS

Non-Destructive Drum Open/Close subsystem (NDDOC)

The primary function of the Non-Destructive Drum Open/Close (NDDOC) subsystem is to open drums while maintaining confinement. The NDDOC provides the flexibility to reuse drums if necessary. The end user will make a determination on a drum-by-drum basis if the drum is to be reused or not. The NDDOC also closes drums, seals them as applicable, and detaches the drums from the glovebox. Specific operations performed in this substation include:

• Provide three drum ports: 1) bagless port for old and new oversized 55-gallon drums for mixed waste packaging, 2) bagged port for new 55-gallon drums for suspect materials, and 3) bagged port for 83-gallon overpacking drum.
• Non-destructively open a 55-gallon drum without physical or structural damage to the drum barrel.
• Securely hold drum in place while liner is being extracted.
• Clean old 55-gallon drum rims in preparation to receive a new gasket and new lid for closing.
• Reclose drum after repackaging is complete using a non-contaminated lid, gasket, and ring.
• Stage new drum lid.
• Close, seal, lower and disengage drums while maintaining confinement.
• Provide procedure to bag-in, -out drums while maintaining confinement.
• Provide protection for confinement bag.
• Position and securely mate drums to their corresponding ports.
• Maintain the drum's outer surface free from contamination.

Material Movement and Liner Transfer Subsystem (MM&LT)

The primary function of the Material Movement and Liner Transfer (MM&LT) subsystem is to extract a drum liner from a 55-gallon drum that is not DOT-certifiable and move it to a certifiable one. This subsystem also performs multiple auxiliary tasks in support of other subsystems. Specific operations performed in this substation include:

• Move full 55-gallon drums from airlock pick-up station to DD&LO catch tray.
• Receive rigid liner and steel drum and lid pieces from SUMR or gloves, for transfer to PWR.
• Move full liner from a drum in a NDDOC port and place it in the DD&LO catch tray.
• Move clean, new, empty, rigid liners and poly overbag from airlock pick-up station and install liner into old drum in NDDOC port.
• Remove rigid liner lid from storage rack .
• Install new rigid liner lid on drum in NDDOC port.
• Place old, full, intact liner into new oversized 55-gallon drum NDDOC port.
• Place old intact liner and "stuck" 55-gallon drum into 83-gallon drum overpack port
• Place bulged old intact liner into 83-gallon overpack drum port.
• Provide a storage rack for liner lids
• Move stack of liner lids from airlock pick up station to storage rack. Separate the package to make lids accessible one-by-one.
• Place and remove funnel/chute over NDDOC drum port.
• Position and remove DD&LO tray restraint to allow transport of waste to 55-gallon drum in NDDOC port. Provide interface for cameras on overhead transporter
• Provide universal tool interchangeability, and other miscellaneous part movement.
• Provide a contingency process in the event a full rigid liner gets "stuck" half-way as it is being pulled out of a drum.
• Move equipment to and from the maintenance area.
• Slide a full and/or empty liner (and its poly bag) into a drum in a drum port without damaging the liner, bag, or drum

Suspect Material Removal Subsystem

The primary function of the Suspect Material Removal (SUMR) subsystem is to remove the suspect materials that are not acceptable under the current WIPP WAC. Specific operations performed in this substation include:

• Move drum and liner pieces from DD&LO catch tray to MM&LT.
• Cut open poly bags from individually bagged items or the poly overbags that encompass the entire waste contents of a drum.
• Locate and remove suspect materials from the DD&LO catch tray to the suspect material drum port or bag-out port.
• Move waste from DD&LO catch tray to a drum in the NDDOC port.
• Resize contents, if needed, to fit in new drum/liner
• Close and seal poly overbag.
• Remove and replace the DD&LO catch tray restraint.
• Wipe rigid liner exterior surfaces. This functionality is needed most when the rigid liner was removed from a drum with free liquids in the annulus between the steel drum and the rigid liner.
• Treat any liquid that is left in the DD&LO catch tray.
• As possible, treat any free liquids from non-debris waste drums that are enclosed inside the rigid liner.
• Treat any free liquids enclosed within the individual containers for debris waste.

SUPPORT SUBSYSTEMS

Integrated Control System

The primary function of the control systems for the HANDSS-55 is to provide integration and continuity to the operation of the subsystems. The control system remotely controls and/or monitors the subsystems from a single location. The subsystems are also able to be operated from separate or individual stations. Data collections are available offsite for statistical analysis and other data manipulation as needed by facility operations personnel. The control system is able to detect off-normal conditions and provide adequate correction/response to the process.

Process Waste Reduction (PWR)

The primary function of the Process Waste Reduction (PWR) subsystem is to accept old steel drums, liner, poly bags, and other materials generated by the various subsystems that need to be excessed from the HANDSS-55. This subsystem will potentially shred and/or compact these materials and package for storage and/or disposal. Specific operations performed in this substation include:

• Accept pieces of 55-gallon steel drums used to store transuranic waste. Accept rigid liners and lids, poly bags, drum lids, and lid gaskets, and possibly other items for waste volume reduction.
• Place volume-reduced items in standard 55-gallon drums.

Destructive Drum and Liner Opening Subsystem (DD&LO)

Working in conjunction with the MM&LT, the function of the Destructive Drum and Liner Opening subsystem (DD&LO) is to destructively open damaged drums to allow access to the liners for transfer. It also can destructively open the drum liner to allow access to the drum contents. Specific operations performed in the substation include:

• Cut and separate metal drums from rigid liners.
• Cut and separate rigid liners from waste.
• Includes a DD&LO catch tray with one removable side to contain the volume of a 55-gallon drum. The tray is configured to prevent waste from escaping from the catch tray.
• Assist the SUMR while cleaning the external surfaces of rigid liners.

Glovebox and Airlocks

This housing structure provides protection from the elements for the system hardware and confinement for materials that being processed by the HANDSS-55. Other functions of the glovebox are: to provide access to the various subsystems hardware; access by gloveports to the entire structure for decontamination; storage space for process materials such as new liner lids; interfaces to power, heating, ventilation, and air conditioning, and other utilities; and camera ports to allow real-time monitoring of operations inside the glovebox. The airlocks provide the ability to transport materials in and out of the glovebox while maintaining confinement. Specific operations performed in this substation include:

• Integrate functionality of individual subsystems
• Provide contingency support for the other subsystems.
• Provide space for a glove-accessed area to perform minor repairs and maintenance on any of the hardware in the glove box.
• Provide a storage location for the rigid liner lids (MM&LT designs the rack).
• Provide adequate lighting within the glove box
• Provide interface to power, compressed air and other utilities for all stations and several outlets within reach of the glove ports for miscellaneous tools.
• Provide a storage location for the funnel/chute.
• Provide a storage location for the liner lids.
• Provide a general storage area for miscellaneous tools.
• Provide interface to cameras for direct vertical view into all drum ports, aerial view of DD&LO, airlock pick-up station, SUMR, and PWR stations, and overall view of stations and equipment.
• Provide airlock technology to transfer drums and other materials into the glove box without spreading contamination outside the glove box.