DECONTAMINATION AND SIZE REDUCTION OF PLUTONIUM-CONTAMINATED PROCESS EXHAUST DUCTWORK AND GLOVE BOXES

Patrick LaFrate, John Elliott, David Siddoway, and Miguel Velasquez
Los Alamos National Laboratory

ABSTRACT

The Los Alamos National Laboratory (LANL) Decommissioning Project has decontaminated and demolished two filter plenum buildings at Technical Area 21 (TA-21). During the project, a former hot cell was retrofitted for decontamination and size reduction of 1100 linear ft. of process exhaust and glove boxes highly contaminated with plutonium. Plutonium-238 and Pu-239 concentrations were as high as 1 Ci per linear foot and averaged approximately 1 mCi per linear ft.

The project's objective was to reduce plutonium contamination on surfaces to below transuranic levels. If possible, metal surfaces were further decontaminated to meet Science and Ecology Group (SEG) waste classification guidelines so that the metal could be recycled at the SEG facility in Oak Ridge, Tennessee. Ninety percent of all radioactive waste for the project was eventually characterized as low-level radioactive waste (LLRW). Twenty percent of this material was shipped to SEG.

This paper focuses on process exhaust and glove box decontamination methodology, size reduction techniques, waste characterization, engineering controls, worker protection, lessons learned, and waste minimization. Decontamination objectives are discussed in detail. The paper also presents the project' s surface contamination acceptance criteria for LLRW, low-level radioactive waste, transuranic waste, and SEG waste.

INTRODUCTION

The Los Alamos National Laboratory (LANL) Decommissioning Project has decontaminated and demolished two filter plenum buildings at Technical Area 21 (TA-21). During the project, a former hot cell was retrofitted for decontamination and size reduction of process exhaust and glove boxes highly contaminated with plutonium. Pu-238 and Pu-239 concentrations were as high as 1 Ci per linear foot and averaged approximately 1 mCi per linear foot.

Decommissioning the filter buildings involved removing all hoods, glove boxes, and process exhaust inside buildings 3 and 4 north; removing exterior process exhaust ductwork and stanchions from buildings 3 and 4 north and building 21; decontaminating and removing the fifescreen plenum and rotary falter plenums; dismantling equipment inside the filter buildings; and razing the buildings.

The primary objective of decontaminating the process exhaust ductwork and glove boxes was to reduce the plutonium contamination on surfaces to below transuranic levels. If possible, metal surfaces were further decontaminated to meet Science and Ecology Group (SEG) waste acceptance criteria so that the metal could be recycled at the SEG facility in Oak Ridge, Tennessee. The project scope included managing all generated waste, with considerable attention paid to minimizing waste, particularly transuranic (TRU) waste, by decontamination and waste segregation. Waste management activities included characterization, segregation, decontamination, packaging, and transportation to LANL's waste management groups. This paper focuses on methodology for decontaminating process exhaust ductwork and glove boxes, size reduction techniques, waste characterization, waste minimization, engineering controls, worker protection, and lessons learned.

SITE/FACILITY DESCRIPTIONS

TA-21, also known as "DP West Site," is located on LANL's northern edge at an elevation of 7,140 ft. TA-21 centers on DP Mesa, immediately east-southeast of the Los Alamos townsite. Figure 1 shows the project buildings and structures in relation to the DP West site.

DP West began operations in September 1945. Its main purpose was to produce metal and alloys of plutonium from the nitrate solution feedstock sent from other production facilities. This process involved several acid dissolution and chemical precipitation steps to separate the plutonium and other valuable actinides from the feedstocks. A major research objective at DP West was to develop new purification techniques that would increase the efficiency of the separation processes. These separation techniques used a wide range of chemicals from the periodic table. In conjunction with efforts to improve purification techniques in the main process lines, studies focused on repressing waste to further enhance recovery. Occasional nuclear fuel reprocessing and activities unrelated to plutonium processing were also performed at DP West.

Filter Buildings 146 and 324

Filter buildings 146 and 324 provided process exhaust ventilation for all plutonium processing and research activities at TA-21. At one point, buildings 2, 3, 4, 5, 21, and 150, with approximately 1100 linear feet of process exhaust duct work were tied into the system.

Initial airflow from buildings 3, 4, and 21 passed through the firescreen plenum into the building 146 plenum. The plenum led to a large, dram-shaped, high-efficiency particulate air (HEAP) filter system. The dram diameter was approximately 92 in., and length was 91.5 in. The dram contained a total of 24 filters--3 filters arranged along each of the drum's 8 sides.

The ventilation flow entered the outer region of the filter housing, passed through the filters into the center of the drum, exited the exhaust duct, and then was sent to building 324. Building 324 acted as the second stage of filtration. The airflow into building 324 passed through 20 parallel HEAP filters, split into 2 paths, each with an exhaust fan, and then recombined and exited the stack.

Approximately 350 ft of stainless 16-gauge, 24-in. and 36-in.-diameter process exhaust duct ran from buildings 3 and 4 north along elevated stanchions to the firescreen plenum. Another 60 ft of 16-in.-diameter galvanized duct ran from building 21 to the firescreen. The interior of buildings 3 and 4 north also contained ductwork of varying sizes, fume hoods, and glove boxes, all of which were tied into the process exhaust system.

Firescreen Plenum

As part of an interim upgrading project, the firescreen plenum (structure 329) was constructed in 1972. The process airflow was rerouted to first enter the firescreen plenum, which housed a wall of metal screen filters which were designed to prevent fire from reaching the main filter plenums. The firescreen was also equipped with an automatic sprinkler head and was intended to be connected to the main radioactive liquid waste system.

DECONTAMINATION OPERATION CONTAINMENT ENCLOSURES

Hot-Cell Containment

The initial enclosure used to house decontamination operations was built in a decommissioned hot cell located in building 4 north (Fig. 2). Usable floor space was approximately 10 ft wide by 30 ft long. Interior ceiling height was approximately 15 ft. The interior of the hot cell was framed with tube and clamp scaffolding, which formed the support for the containment. Six-mil poly sheeting hung from the scaffolding formed the walls, ceiling, and floor of the containment. Walls and ceiling were covered with two layers of poly, and the floor was covered with three layers. Seams were sealed with spray adhesive and duct tape. The 4-ft-thick wails of the hot cell served as the framework to support the doors of an air lock. Air-lock doors consisted of three overlapping sheets of poly hung with spray adhesive and duct tape on each side of the 4 ft thick hot-cell doorframe. The air lock was 6 ft wide, 8 ft high, and 4 ft deep.

Flexible duct was installed through an existing opening In the hot-cell wall at the end opposite the air-lock entrance. A 2000 cubic foot per minute (cfm) HEAP-filtered air handler connected to the flexible duct provided negative air pressure within the containment. Two flexible ducts routed inside the containment served as engineering controls for airborne contamination at their source. The first duct extended along approximately one-third of the containment wall. The second duct extended along almost the entire length of the wall. Other flexible ducts were extended just through the wall of the containment to provide general negative pressure on the enclosure. Other items installed in the containment were a HEAP vacuum, low-volume air samplers, an alpha continuous air monitor (CAM), worktables, and tools. Consumable supplies in clear plastic bags were hung from the containment walls with duct

The containment underwent several modifications as the decontamination process evolved. First was the installation of an additional 2000-cfm HEAP negative air handler. This unit was attached to the flexible duct that had been installed earlier. Adding a second negative air unit resulted in more frequent air exchanges in the containment (approximately every 2 minutes) and significantly improved airborne contamination control.

A second modification was the construction of a much larger air lock, approximately 10 ft long, 10 ft wide, and 8 ft high. This air lock was framed with 1.5-in.-diameter polyvinyl chloride (PVC) tubing and covered with two layers of 6-mil poly sheeting. The air-lock inner and outer doors, which opened across the full width of the air lock, were also framed with PVC tubing. Doors were hinged to open from the center. The hinges were constructed from interlocking PVC "T" fittings on the door and air-lock frames (Fig. 2). The enlarged air lock introduced several improvements to the decontamination process. First, it greatly eased the regulation of airflow into the containment, which now became a matter of simply opening or closing the doors. Second, it greatly enhanced the movement of pieces of duct, glove boxes, tools, supplies, and waste into and out of the containment. Third, it provided an egress area for all workers to doff personal protective equipment (PPE) in the event of an unplanned airborne contamination release.

Room 406 Containment

To improve decontamination and size reduction output, a second, larger containment was constructed in an area adjacent to the hot cell (Fig. 3). This containment was also framed with tube and clamp scaffolding and covered with a double layer of 6-mil poly sheeting. Large air locks were constructed at each end of the containment, one primarily for crew entry/exit and the second for movement of equipment and items in and out of the containment. These air locks were constructed of tube and clamp scaffolding and covered in two layers of poly sheeting. Air-lock doors were constructed of three overlapping sheets of poly sheeting. Three 1500-cfm HEAP negative air handlers were connected to the containment by means of flexible 8-in. duct. Several lengths of duct running along the sides of the containment enabled the crew to place a negative air inlet at the work surface. The combined capacity of the negative air units resulted in an air change within the containment every 2 minutes. A low-volume air sampler, a CAM, worktables, tools, and supplies were also installed in the containment.

DECONTAMINATION METHODOLOGY

Decontamination Methodology Evaluation

Before duct decontamination began, the project evaluated two decontamination methodologies-brushing and strippable coatings.

Brushing

The project first evaluated brushing as a decontamination method. Personnel performing the brushing operation each wore 2 pair of cotton coverall "anti-Cs," anti-C undergarments (surgeons' scrubs), heavy latex gloves with 15-in. cuffs, and a skull cap. A final outer layer consisted of Tyvek coveralls with attached booties and hood, shoe covers, a final pair of heavy latex gloves, and a full-face air-purifying respirator with HEAP cartridge. All openings in the anti-Cs and tyvek were taped.

A containment prepared with HEAP-filtered exhaust provided negative air pressure. The stainless-steel end caps covering the duct ends were removed with a HEAP vacuum held at the work point. After both end caps were removed, the radiological control technician (RCT) evaluated contamination levels. Direct survey results at beth ends of the duct indicated contamination levels in excess of 4,000,000 dpm/100 cm² alpha (saturation point of the instrument). Smears collected at the same locations indicated removable contamination levels of approximately 200,000 dpm/100 cm² alpha. Dose rate was indistinguishable from background.

Personnel used a wire brush (a less than $5.00 hand tool) to attempt decontamination. A 6-in. by 12-in. area was brushed for 5 to 10 minutes, with a HEAP vacuum collecting the dust. After the brushing, there was a visible difference in the appearance of the decontaminated area. Evaluation of this area indicated that the contamination had been reduced from greater than 4,000,000 dpm/100 cm² to 200,000 dpm/100 cm². Airborne contamination levels reached a peak of 45 derived air concentration (DAC) Pu-239.

Strippable Coatings

The project also evaluated the use of strippable coatings for decontamination. Two different coatings were evaluated: ALARA 1146 cavity paint, a commercially available product; and SensorCoat, a product developed and produced by LANL. SensorCoat is a water-based, nontoxic, polymer strippable coating. A color change in the SensorCoat indicates the presence of contamination. The SensorCoat was evaluated in three different formulations: 4% glycerin, 8% glycerin, and 12% glycerin. The higher the percentage of glycerin in the SensorCoat, the higher the viscosity and the better the adhesion.

For this decontamination evaluation, we selected the access hatch to the filter plenum in building 146, a piece of stainless steel 3 ft wide by 6 ft long was selected. The hatch was placed fiat on sawhorses inside the containment and unwrapped. Contamination levels were evaluated with an alpha survey meter, a Ludlum Model 139 with an air proportional detector. Direct survey measurements indicated contamination levels in excess of 4,000,000 dpm/100 cm² spread uniformly over the hatch surface. The hatch was then divided into five equal sections. One section was left unpainted. The other four sections were brush-painted as follows: one with the ALARA cavity paint, one with the 4% glycerin SensorCoat, one with the 8% glycerin SensorCoat, and one with the 12% glycerin SensorCoat. After the ALARA paint and SensorCoat dried for 48 hours (over a weekend), they were removed and surface contamination levels were reevaluated. The results follow:

An evaluation of the results would indicate that the 12% glycerin SensorCoat provides superior decontamination. However, the SensorCoat proved to be difficult to use on anything but horizontal surfaces because it ran down curved or vertical surfaces. The SensorCoat also proved to be more difficult to strip than the ALARA cavity paint. With further development, the SensorCoat may prove to be an extremely useful alternative to commercial products. Additional information on SensorCoat may be obtained from Betty Jorgensen, MST-7, Mail Stop E549, Los Alamos National Laboratory, Los Alamos, NM 87545; phone: (505) 667-7059 or fax: (505) 667-8109.

Process Exhaust Decontamination

Brushing was selected as the method to decontaminate the process exhaust duct. Before decontamination work began, the brushing process was discussed in great detail with management, craftspeople, and the RCTs. The basic process involved driving a commercially available brush through the ductwork and capturing the radioactive contaminant in a HEAP vacuum cleaner. The main components for the brushing operation were the brush attachment, brushes, driver motors, shafts, a HEAP vacuum cleaner, a rolling platform, and glove bags (Fig. 4). A work package was developed to control work and to identify and mitigate hazards. This work package consisted of decontamination procedures, a task hazard analysis, and the radiological work permit.

The brush attachment assembly and end cap, approximately 1 in. greater in diameter than the duct being brushed, were fabricated out of 22-gauge sheet metal. A 11/2-in. shaft attachment was welded in the center of the brush attachment to insert the shaft driver through the duct. The shaft was a 3/8-in. black piping salvaged from the scrap pile. The driver initially was a 1/2-in. drill motor. Brushing 24-in.-diameter ductwork, however, required 1/2-in. shafts and 3/4-in. drill motors. The brushes were purchased from a commercial dealer and were sized 1/2-in. larger in diameter than the ductwork being decontaminated. Asbestos abatement glove bags were modified on location to accept various sizes of brush attachments and ducts. A rolling platform was fabricated with "V" attachments on each end to accept ductwork ranging from 12 in. to 36 in. in diameter.

For the process exhaust decontamination, the ductwork was placed on the platform, and a glove bag was attached to the duct' s outflow side. A HEAP vacuum hose attached to the bag drew the contaminant through the duct while the brushing was being performed. A second glove bag was attached to the intake side of the duct and the brush attachment. The glove bags were tested for leakage by application of hand pressure and by visual inspection.

The vacuum cleaner was turned on, which caused a negative pressure on the ductwork. Two-in.-diameter plugs were cut from the duct at 4 different locations with a hole saw. The RCTs then took direct readings from the plugs to determine the levels of fixed and removable contamination. Plugs were strategically located, typically on the underside of the duct, to sample areas of maximum contamination. If direct measurements exceeded predetermined values, the plugs were bagged out of the containment area and analyzed specifically for Am-241 concentration by gamma spectroscopy. Gamma spectroscopy and/or direct measurement results were then conveyed to the decontamination crew. At this point, either the brush operation continued or, if the results were negative, the glove bags were removed, the ends of the duct were capped, the duct was wrapped with sheet plastic to control contamination, and then the duct was removed from containment and staged for disposal.

If radioactive contamination exceeded transuranic levels the duct was further decontaminated by brushing. A crew member, stationed at the end of the duct where the vacuum was attached, verified that the brush was performing the job as designed, as well as monitored the vacuum cleaner. The number of passes of the brush depended on the length of the duct being cleaned. For example, a typical 20-ft-long duct would undergo two passes of the brush. Once the crew believed the duct was cleaned, another set of plugs was drilled and sampled. As soon as the samples proved acceptable, the glove bags and attachments were removed in reverse order of installation. If the brush had not worn to the point of being ineffective, it was retained in its glove bag, with a second glove bag fitted over the first, and reused on the next duct. If the brush was worn out, it was discarded as TRU waste.

Glove Box Decontamination

Glove boxes were set on either crank-up tables or pallet dollies and moved to the end of the room 406 containment, where the negative air inlets were located (Fig. 3). A negative air flexible duct was attached to a glove box at the pan (bottom) level so air could be drawn from the cleanest part, that is, the top and sides, across the bottom and out. Most glove boxes had ports at beth ends, which made this task easier. In some cases, a glove port was used. Many of the glove boxes still had their make-up HEAP-filtered air systems intact and were uncovered after the flexible duct was attached. Once the negative air flexible duct was connected to a glove box and functional, a panel at the opposite top end of the glove box was either unbolted or cut to open up an entry. Nibblers were primarily used to cut up the glove boxes; however, reciprocating saws and portable band saws were also used. Tools were selected on the basis of cutting effectiveness and to be nonspark producing for fife prevention.

Direct measurements on the glove boxes determined alpha contamination levels. ALARA cavity paint was applied to the glove box, allowed to dry, and then stripped and bagged out near the negative air end of the box. This process was repeated until no appreciable loose contamination could be removed and contamination levels were below TRU, and if possible within SEG waste acceptance criteria. Asbestos "lock down" (a commercially available asbestos abakement fixative) was then sprayed on the interior surfaces of the glove box. On some of the glove boxes, a commercial cleaner such as Fantastik was used to finish removing the loose contamination.

Survey information gathered after glove box decontamination guided the glove box disassembly, which was started at the top end opposite the negative air connection. The reason for starting disassembly toward the negative airflow is to pull the contaminated metal flakes away from the workers and keep the containment as clean as possible. Nibblers were used for most of the cutting; however, reciprocating saws were used on thicker materials. Cordless drills and basic hand tools were used to remove bolts, screws, glass, and gasketing. The only glove-box piece that could not be decontaminated below TRU levels was typically the bottom pan and occasionally 6 to 8 inches of the sides. The glove-box pieces were strategically cut, wrapped, and stacked to take maximum advantage of the space within the waste boxes.

As glove boxes were being size-reduced, the wrapped pieces were marked and color coded according to their radiological levels. The color code was magenta for TRU and yellow for low-level waste. The waste packages were then wiped down and staged near the air lock farthest away from the negative air inlets. As the waste was removed from the containment, one laborer entered the air lock and another was in the containment. The laborer in the air lock had "clean" bags and double-bagged the waste delivered by laborer in the containment. The laborer in the air lock never stepped into the containment, nor did the containment laborer step into the air lock. Once the waste was double bagged and marked, it was put in either the TRU waste or low-level waste containers.

Process Improvements

During the early stages of the duct decontamination, sawhorses supported the duct. These proved to be too low for worker comfort, and they allowed the duct to roll. The sawhorses were replaced by adjustable height "V" stands that cradled the duct. The "V" stands were a tremendous improvement; however, the duct still had to be manually introduced into or removed from the containment The decommissioning contractor craftspeople designed and fabricated a rolling 3-ft by 5-ft cart with "V"-shaped duct support arms. A forklift loaded the duct onto the cart, and the cart was then rolled into the containment. The duct was then decontaminated to acceptable levels and capped, and the exterior surfaces of the duct and cart were decontaminated so they could be removed from the containment. After the duct and cart were removed from the containment, the duct was unloaded from the cart with a forklift. The can eliminated the need for workers to handle the duct and placed the duct at a comfortable work height. Turnaround time between decontaminating pieces of duct was reduced, increasing productivity.

During brushing operations, the RCT performing direct measurements of the containment floor and worktables noticed increased contamination levels in the containment. Operations were halted until the source of contamination was identified and controls were put in place. Investigation indicated that a partial blockage in the HEAP vacuum hose reduced the negative airflow on the interior of the duct. This blockage allowed a large amount of airborne contamination into the containment through the makeup air holes in the wire brush shroud. The corrective action was to provide HEAP-filtered makeup air to the interior of the duct being decontaminated. Short pieces of tubing were welded over the makeup air holes in the brush shroud. Four vacuum cleaner hoses were attached to this tubing, and a metal adapter connected the hoses to a standard 2-ft by 2-ft HEAP filter. This simple solution prevented any further releases during duct decontamination with wire brushes. This contingency plan also eliminated any contaminant release from inside the duct to the containment when the vacuum ceased because of electrical power loss, equipment failure, or employee error. An alpha CAM was introduced into containment and was set to alarm at 15 DAC-hrs. This alarm gave a real-time warming of increased airborne contamination concentrations in containment enabling personnel to immediately evacuate to the air lock.

Because of the extent of the initial alpha contamination on much of the ductwork, the standard configuration of the direct alpha measuring equipment caused saturation of the instrument at around 4,000,000 dpm/100 cm². There were two solutions to the instrument saturation. One solution was to cover 90 percent of the active area of a Ludlum 443 ZnS probe with duct tape. The active probe area was reduced to a 2.8-em-diameter circle. A 2.8-cm-diameter Pu-239 check source then established a reduced efficiency for alpha. This solution allowed a somewhat more accurate way of measuring alpha contamination to levels approaching 6,000,000 dpm/100 cm². A second solution was to work with the instrument manufacturer to modify a Ludlum 2350 count-rate meter/scaler to increase its maximum range to greater than 10,000,000 dpm/100 cm².

WASTE MANAGEMENT

Waste minimization was a significant project goal. Particular attention was paid to decontaminating TRU waste to low-level waste. Initially, TRU waste constituted 120 m³ of the total. Decontamination and compaction of the remaining fraction of TRU waste reduced this amount to 17 m³. Low-level waste was also compacted on-site. Contaminated metal was recycled by two different companies, SEG in Oak Ridge, Tennessee, and the Savannah River Plant. A considerable amount of steel was surveyed and free-released. Decontaminating a portion of the building structures enabled free-release of all this demolition debris. This material was crushed and recycled. Waste acceptance criteria for the project follow:

Telescoping and cutting (with nibblers, reciprocating saws, and shears) were the two primary methods used to reduce the ductwork in size and package it. Telescoping the smaller ducts into larger ducts increased the density of the transportainers (8-ft by 8-ft by 20-ft sea/land containers) used to ship the waste to the low-level radioactive disposal site. Each piece of duct was sprayed with asbestos "lock down" before the smaller duct was inserted into the larger.

Difficulties were encountered during the insertion process because of insufficient negative airflow on the larger duct creating an airborne contamination hazard. The remedy was to place a poly liner on the outer diameter of the larger duct and allow the smaller duct to seal against the poly as it was manually pushed in. The poly end cap on the smaller duct was cut and the vacuum hose attached before the next piece of duct was inserted.

LESSONS LEARNED

Duct decontamination proved very difficult Decontamination processes evolved continually, with airborne emissions and production concerns being the major drivers. Initially, strippable fixatives were sprayed inside a removed section of duct, the duct was cut in half, and the fixative was peeled off. This initial process resulted in airborne emissions that would have required supplied-air respiratory protection if decontamination were performed for a full day. The process was costly and involved a greatly increased risk of worker contamination. The process was modified such that the duct was brushed out, with many engineering barriers to control the airborne radioactive emissions. Since TRU waste must be size- reduced to fit in drums or standard waste boxes, disposal alone can be difficult. Glove boxes proved the easiest to decontaminate and size-reduce.

All glove-boxes were contaminated with Pu-239, the exception being a glove box that contained Pu-238. After it became apparent that the Tyvek material used for the outer layer of anti-C protective clothing was permeable to Pu-238 contamination, the Pu-238-contaminated glove-box treated differently. Common practice was for the RCTs to "frisk" the workers' anti-Cs as they doffed. It became apparent that the contamination had somehow wicked its way through the outer layer of Tyvek on to the inner layer of cloth coveralls. Upon further investigation, the contaminant was identified as Pu-238. As a result, decontamination of this glove box required more restrictive engineering and handling controls. The handling time required for this glove box was approximately 30% more than that required for the Pu-239 glove boxes.

Three other lessons learned deserve mention. First is the importance of verifying that all systems are operational before the decontamination process begins. Second is the importance of developing contingency plans for equipment or electrical power failure. And third is the importance of employees staying focused on the task at hand.

In one particular case, a vacuum cleaner failed during a critical operation, and negative airflow to the duct was lost. Investigation after the incident proved that only the individual who had plugged in the unit had knowledge of the power source. This situation caused concern, and a contingency plan was established and implemented allowing employees working the process to verify the location of the power source for each piece of equipment being used.

The decontamination of the ductwork lasted approximately 2 months, and it was difficult to keep individual team members on the same crew; therefore, training was required each time a new member entered the operation. Keeping a concentrated focus was difficult. Initially we were entering the containment 3 times in a I0- hour shift, but as the ductwork pieces became larger and harder to handle, we restricted the shift to 2 entries. To maximize cost effectiveness, we concentrated on other tasks during the remaining time.

CONCLUSIONS

Relying on the project plan, the site-specific health and safety plan, and individual task work packages as the authorization basis proved efficient and cost effective. Discussing critical operations with risk management experts avoided unnecessary documentation and concentrated attention on important risks. The project' s safety record was very good: there were no radiological incidents, reportable occurrences, or worker injuries. Many factors contributed to this record. Active involvement of the entire project team, and particularly the decommissioning workers, resulted in thorough requirement identification and appropriate hazard analysis and communication. Worker input into procedures ensured efficient, safe work packages. Daily safety meetings introduced and reinforced safety topics.

It is possible to decontaminate and size-reduce highly contaminated (transuranic) process exhaust and glove boxes safely and economically. The size- reduction efforts on the entire project resulted in a waste disposal cost savings of 3.3 million dollars. The knowledge and expertise gained will play a major role in cost savings in future decontamination and decommissioning projects.

During several brainstorming sessions, personnel scheduled to perform the job generated all the ideas and techniques that were incorporated into the work procedures. First, the idea to fabricate the end cap came from our sheet metal foreman. Second, an RCT recognized the need for HEAP filtered makeup air to eliminate any release of contaminants abakement. Third, the glove bags were fabricated on-site with the use of commercially available asbestos bags for each particular application. Since designated teams placed the work package in motion, all team members knew their roles and responsibilities.

ACKNOWLEDGMENTS

Dan Stout, TA-21 Decommissioning Project Leader, LANL.

BIBLIOGRAPHY

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