Jeffrey S. Dugdale and Marvin H. Bonta
Los Alamos Technical Associates

Case study of the Deactivation of a DOE Nuclear Facility, Building 886 Rocky Flats Environmental Technology Site, formerly the Critical Mass Laboratory. This case study will illustrate the situational leadership, project management and teamwork necessary to accomplish high hazard work under tight schedules, with shrinking budgets and increased regulatory oversight. The paper will describe the history of the facility, condition upon project start, mission activities, problems encountered, end state results and lessons learned.

Los Alamos Technical Associates (LATA), supporting Safe Sites of Colorado, was responsible for project management of the integrated team tasked with the removal of the Highly Enriched Uranium Nitrate (HEUN) solution inventory, and with the deactivation of the facility in preparation for D&D. Building 886 was considered to have the highest risk for an inadvertent criticality in the DOE Complex. The first phase of the project accomplished the reduction of this criticality risk, and the project culminated in the deactivation of the facility. The challenges facing the integrated team were greatly varied: from understanding the risks associated with the facility and its condition, to designing safe processes and equipment for removal and final deactivation, and meeting regulatory requirements and milestones. While the project performance is considered a success it was not without controversy and challenges to meet the expectations of stakeholders. An examination of the issues and lessons learned during the HEUN draining and Building 886 deactivation will help identify ways in which future success can be ensured for this type of work.

The cessation of weapons production at the Rocky Flats Plant (now the Rocky Flats Environmental Technology Site), located 15 miles west of Denver, Colorado caused a major shift in the plant’s mission. Instead of production, the plant has become a technology test ground for deactivation and remediation of radioactive and hazardous facilities and systems. The Integrated Management team, composed of Kaiser-Hill and its subcontractors Safe Sites of Colorado (SSOC) and Los Alamos Technical Associates (LATA), was tasked to remove the nuclear materials, in order to rapidly reduce the nuclear risks that had been inherent to Rocky Flats for more than 40 years.

Among the first of Rocky Flats buildings to undergo deactivation was Building 886. Located on the southern edge of the plant, Building 886 housed the Critical Mass Laboratory. The primary function of the laboratory was to perform experiments on nuclear and non-nuclear materials to determine criticality reaction properties. In addition to weapon related research, these experiments also helped scientists develop better criticality models, which in turn promoted better nuclear safety. Nuclear materials such as plutonium and uranium, as liquids and solids, were used in the experiments. The laboratory particularly relied upon Highly Enriched Uranyl Nitrate (HEUN), a clear yellow liquid that contained 93% enriched uranium in concentrations approaching 400 grams per liter. The laboratory housed approximately 2700 liters of this HEUN solution, in concentrations of 121 g/l and 368 g/l. The HEUN solution, most of which had been in the building since its construction in 1964, was contained in eight special tanks. The solutions were kept sub-critical during storage by means of boron-impregnated glass rings called Raschig rings. These rings filled each of the eight HEUN tanks, since the tanks themselves were not of a critically safe geometry.

Building 886 posed several technical and management challenges to the SSOC team. First, the building had been operated as a laboratory instead of a production facility. Therefore, accountability and configuration control were almost non-existent. Contamination "hot spots" were widespread, and discovery of latent hazards occurred almost daily. Second, because Building 886 was one of the first buildings to undergo deactivation, the funding allocated to the project was the absolute minimum needed to complete the task. No additional money was provided to account for any unforeseen work or contingency. At the same time, the pressure from clients (Kaiser-Hill and the Department of Energy) was tremendous. Because the HEUN solutions presented one of the highest risks of inadvertent criticality in the Complex, their speedy removal was paramount. Therefore, SSOC accepted responsibility for draining Building 886 under an existing commitment to the Defense Nuclear Facilities Safety Board (DNFSB). In fact, upon taking over the project, SSOC and LATA conducted a review of the schedule and safety implications of the previous contractor’s chosen approach: isotopic blending. The review found that blending the HEUN with natural uranium and then shipping it in a tanker not only posed a great number of technical challenges, but also was less safe than other methods. In addition, the blending approach would not have met the DNFSB commitment date. Consequently, the SSOC/LATA team elected to drain the HEUN from the system and to bottle the solution into critically safe 10-liter polyethylene bottles. The solutions were subsequently shipped to Nuclear Fuel Services (NFS), an offsite contractor charged with solidifying and stabilizing the enriched uranium.

Further uncertainty arose from the condition of the tanks, which had held the dangerous solutions for more than thirty years. While there was process knowledge that could be researched to determine the general nature of the solutions, little or no data existed regarding potential contaminants or exact concentration levels. Also, because the solutions had sat unmixed and unsampled since the Site's shutdown in 1989, the condition of the safety-critical Raschig rings or their boron content was unknown. A walkdown of the exterior of the tanks indicated that the sight gauges (which were made of Tygon® tubing) had not been changed in five years and had become brittle. The long-term stability of the tubing was seriously in question; a gauge could split, dumping the dangerous HEUN into the tank pit. Finally, the general condition of the building equipment was unknown. Pumps and valves had not been cycled for five years, the pipe fittings had not been leak checked or even had liquid in them, and the unexpected discovery of contamination was a frequent event.

In the face of the technical challenges posed by an uncharacterized building, and the budget and schedule pressures imposed by Kaiser-Hill and DOE, SSOC/LATA began the project to remove the HEUN solutions, and to perform the deactivation of the Criticality Mass Laboratory in Building 886.

Upon accepting responsibility for removal of the high hazard HEUN solutions, SSOC/LATA imposed the rigor of the project management discipline on the difficult challenges and uncertainties on the project. The first step was development of the safety basis by which the HEUN draining and subsequent deactivation activities could occur. The team’s first major obligation was to upgrade the existing safety systems to accomplish two objectives: to ensure the continued sub-critical condition of the solutions under any circumstances; and to ensure that the impending removal of those solutions could be accomplished in a facility that provided adequate worker safety. Yet even with the dangerous condition of the building, funding and time schedules dictated that the HEUN be removed with a minimum of cost and delay. Since no future use for the Criticality Mass Laboratory existed, there was no drive to upgrade any of the building's safety or infrastructure systems beyond the minimum needed to support the removal of the HEUN. Recognizing the need for a graded approach, SSOC/LATA completed a Basis of Interim Operation (BIO) for the building, finding and implementing only the minimum set of safety controls necessary to keep the building functioning safely during the removal. The BIO included such safety features as temperature monitoring to ensure that the HEUN would not precipitate out due to low temperatures. Such precipitation could potentially cause a criticality incident.

Once the baseline conditions for the building’s safe operation were established, the next step was to evaluate the necessary project tasks. To this end, the team took advantage of a relatively new process called the Activity Control Envelope (ACE). This rigorous work planning and analysis tool lent itself well to the uncertainties of the HEUN removal. Utilizing a cross-discipline team of criticality, nuclear, and radiological engineers, coupled with project managers, engineers, and the hands-on operators, the ACE team developed a task description, hazards table, and expectations that proved to be very beneficial during operations. Because the ACE had been developed by the right mix of technical skills, and in an atmosphere that allowed careful consideration and analysis, it was widely regarded as the best ACE of its time. But more importantly, it proved to be a touchstone. Workers who were concerned about some aspect of change proposed for the work flow could consult the ACE document or the team members for the safety implications of such a change. In addition, the ACE served to broaden both the distribution and decision making authority for project information and issues, and gave project support people a feeling of teamwork and valued participation.

Another significant technical challenge was overcome through teamwork. Because of the criticality concerns associated with the HEUN solutions, control of the draining process was of tantamount importance. The SSOC/LATA team recognized that the ability to quickly control leaks and to regiment bottle handling procedures would be essential to the safe completion of draining and bottling. Using a design from another draining project at Rocky Flats, the project designed and built a "bottling skid". This skid, housed on two separate sleds, contained a suction pump, a bottle holding and filling device, and three critically safe pencil tanks. In addition, the skid held a prover column, used to verify the volume to be put into each bottle in order to absolutely prevent the overfilling and consequent spillage of the HEUN. The entire skid was designed to be foolproof. Through team development, the skid was designed, procured, fabricated, installed and tested in less than seven months.

Several lessons were learned over the course of the skid’s use. For instance, the skid's three pencil tanks were designed with glass sight gauges. While testing the bottling skid, one of these gauges broke. The breakage was caused by a torque that had been applied to the glass during installation, and led to the modification of the sight glasses to use Tygon® tubing. This tubing, at least in the short term, was pliable and accident resistant, thus affording the operators that worked around these delicate sight gages a wider margin of safety.

The most significant aspect of the bottling skid was not its components, but its cross disciplined design team. Instead of providing process engineers with an idea and specifications, the team decided to design the bottling skid using up-front inputs from not only engineers, but also from the operators of the skid. In fact, preliminary design ideas were passed by the ACE Team, not for approval but with the expectation that they would recognize better way to design or built the skid’s components. One such instance was the design of the prover column, which ensured that the proper amount of HEUN was added to each ten-liter bottle. The engineers had determined that piping standards required the column to be a pressure vessel, even though the maximum pressures that it would withstand would be less than a few psi. The ACE team and operators, working in conjunction suggested design changes to the steel prover column to increase the liquid level visibility. The utility and practicality of the bottling skid are directly attributable to the fact that the criticality engineer’s and radiological engineer’s inputs were joined with the operational considerations. In this way, SSOC/LATA developed a safe method of draining 270 bottles of highly hazardous material, in an ergonomic way that resulted in no design-related accidents.

Finally, the SSOC/LATA team encountered a technical difficulty resulting from the errors made in the past regarding the licensing of shipping containers. A review of the available packaging permissible under the Title 10 and 49 CFR requirements yielded few options. The primary shipping container for the enriched uranium solutions had been the one-liter B&W 5X22 container. However, through extensive research, project engineers determined that there was another, better alternative. In the past, fissile materials had been shipped in ten-liter packages, designated as "FL-10s". The exterior packaging was essentially two 55-gallon drums welded end to end. The addition of a heavy steel inner containment tube and special foam completed this approved Type B package. While these containers, each capable of transporting ten liters of solution, were very attractive to the project, LATA discovered that, due to their aged condition and infrequent use, only about 75 packages were still in existence. In addition, while the remaining FL-10s were still covered by valid license certification, their condition was less than adequate. Many containers were missing parts, or had punctures, scrapes, or dents. Working in conjunction with the SSOC Packaging Engineering function, the project repaired and certified approximately 63 of the FL-10s to the existing standard.

The FL-10 repairs were often difficult to achieve, however, because certified spare parts were nonexistent. In particular, many FL-10 containers failed their inspection/certification because of missing or damaged foam plugs. The foam plug covers the top of the tube (wherein the bottle is stored) and provides shock support for the lid area of the container. These plugs were made from a special foam certified many years earlier, and most were seriously deteriorated. Unfortunately, the foam was no longer available, and the project schedule did not allow the time to test new plug materials. In response, project engineers, working closely with packaging engineers and NRC licensing authorities, searched the certificate of compliance for the containers, and discovered that it was permissible to repair small holes in the plugs with a designated resin. This resin was located and procured both to repair the existing plugs, and to coat the plug surfaces to make them more resilient. Containers that were damaged beyond acceptable repair standards were scavenged for foam plugs and other parts needed to make whole, certified containers. In total, the project, through a combined team effort and some ingenuity, placed 63 containers into service.

The containers were shipped in trucks, with a truckload being defined as twenty containers. Therefore, having at least 60 usable containers meant that 40 could be "en route" at any one time, while the third set of 20 would be in packaging. To ensure the full utilization and minimum downtime for these containers, the project developed detailed packaging and shipping schedules and projections. The project recognized that maximum efficiency could only be achieved by minimizing the time that a container was empty and not in transit. As bottling and packaging efficiencies grew from three packages per day to ten packages per day, the project worked to minimize the container return cycle, in order to prevent the draining and packaging operations from having to wait for containers. In the final analysis, there were only a few days in which packaging operations were curtailed due to a lack of shipping containers. This was possible not only because of good contingency planning and execution, but also due to the tremendous logistical teamwork displayed by SSOC, LATA, Kaiser-Hill, and the DOE Transportation Safety Division.

During the HEUN planning phase, the selected bottling and shipping approach required the use of criticality safe ten-liter bottles, made of high density polyethylene. The assumption was made that although several different drawings existed for the bottles, the overall configuration and designation of this bottle type made it acceptable to ship HEUN solutions in an FL-10 overpack. The decision was made to locate the only known vendor that could manufacture the bottles and procure enough to drain and ship the HEUN from Building 886. Careful reading the SAR for the FL-10 revealed that only two drawings were listed on the license as acceptable for shipment of the solutions: the CAPE drawing, and a drawing on file with NFS, the subcontractor. Neither of these two drawings were in the possession of the team at the time the bottle production orders were let.

A team consisting of LATA, SSOC, NFS and Kaiser-Hill researched the essential dimensional requirements of the several different existing ten-liter bottle drawings. The features were identified and a white paper summarizing those features was written. A certification sequence was developed, through which each bottle was inspected or representative testing was performed, to demonstrate the integrity of each 10 liter bottle used to contain and ship the HEUN solution. In addition, through much research, it was discovered that the vendor manufacturing the 10 liter bottles had the only previously certified mold for the blow molding process in existence. Using the testing data, dimensional inspection results and the mold history, NFS agreed to revise the drawing of which they had control, and to submit that revision for a modification to the SAR and license held by the NRC.

In a joint effort, the ten-liter polyethylene bottle change package was written and submitted to the NRC in two days. With the help of the DOE Rocky Flats Field Office and SSOC/LATA’s subcontractor, the package was approved and the SAR and license amended within three days.

The draining of the HEUN, and subsequent bottling, packaging, and shipment were completed in just under five months. Following the draining of the tanks, the project team had planned to perform ordinary tank closure activities of rinsing and blanking off the process lines. The uranium-contaminated rinse solution was to have been sent to the offsite contractor (NFS) for uranium recovery.

In preparing for the rinsing operation, a LATA engineer proposed a cost saving idea. LATA recognized that the planned rinsing of the tanks was the result of a paradigm onsite that all tanks had to rinsed before Raschig ring removal and tank closure. The stable nature of HEUN, coupled with the non-RCRA regulated status of the tanks, allowed the rinsing step to be avoided. By skipping the rinsing step and proceeding directly to ring removal, a substantial cost savings would result. In addition, the deletion of rinsing was justified on safety grounds. Because the HEUN tanks had been drained as a direct result of the criticality hazard, it seemed highly imprudent to reintroduce liquids into the system, resulting in continued risk of leak and an inadvertent criticality accident. Therefore, SSOC/LATA proposed to KH and to the DOE to delete the funded rinsing scope, and move directly to ring removal. In doing so, SSOC showed a calculated cost savings of over $500,000. The ring removal, slated to have been done in FY98, was done in FY97 with no additional funds being added to the project’s budget. SSOC/LATA also recognized that the lessons learned on the low radiological hazard uranium tanks would be invaluable to the ring removal efforts on a multitude of high hazard Pu tanks in the near future.

Coincident with the removal of the rings, deactivation of the building also required the removal of as much hold-up solution as could be practicably removed from the tanks and piping in the building. Following completion of the initial draining of the HEUN, the project estimated that approximately three kgs of enriched uranium remained held-up in the piping, tanks, and associated equipment. Some of this material was known to be in liquid form, and some was suspected to be in solid, (crystalline) form. As such, the project engineers had to design a draining method that would accomplish three things. First, the primary focus of the draining was to remove as much material as possible. Second, the method had to maximize the coverage of areas where non-destructive assay scans indicated material, but where the material was suspected to be in solid form (UNH crystals are highly soluble). Third, and in conflict with the second priority, the method had to minimize the passage of solutions through piping that was thought to be empty. The piping had presumably not held liquid in at least five years, and its integrity was in question. The engineers, working in conjunction with safety engineers and process specialists, developed a method whereby the system was drained through the existing pump skid in one room, and through a cold-tapped header in the other room. During the draining of the entire building, a total of 2675 liters (506 kgs of enriched uranium) were recovered.

The draining of the HEUN tanks resulted in the opportunity to reduce the security requirements for Building 886. In the past, the building had required a separate security fence and guardhouse, due to the presence of highly enriched uranium. However, even before the final draining, the Material Access Area designation was removed, and the fence around the building complex was torn down. This security reduction was estimated to save taxpayers $300,000, by freeing up the guards to perform other security functions.

The ring removal and final hold-up draining completed the essential tasks in the deactivation of Building 886. While other tasks were listed in the deactivation plans, such as the removal of several reactors used for lab experiments, the removal of the material was the primary deactivation objective, and resulted in significant cost reductions and safety improvements.

In retrospect, several central lessons can be derived from SSOC/LATA’s experiences in Building 886. The deactivation of Building 886, and the associated draining of the HEUN can be regarded as a pilot project for Rocky Flats, and perhaps generally for the whole Weapons Complex. Due to the building’s small size and straightforward hazards, Building 886 was a perfect project with which to demonstrate the SSOC/LATA team’s capabilities in the deactivation of nuclear facilities. While other projects at Rocky Flats have deactivated buildings, these were not nuclear buildings which had significant quantities of fissile materials. Therefore these prior experiences are less helpful than those lessons learned during the deactivation of Building 886. Other lessons include the requirement for a true team effort, the benefit of strong situational leadership, and the need for good contingency planning and innovation.

The need for a good team effort has long been understood for the success of most projects. However, when a complex project undergoes a time crunch, the tendency of many projects is to revert to the direction and leadership of the project manager, acting in a largely autocratic fashion. It is true that competent project management greatly increases the potential for a project to succeed. But, SSOC/LATA showed that a team of people, guided by strong leadership but free to define their contribution to the team, can exceed anyone’s reasonable expectations. Every facet of this project and virtually every decision were the product of a cooperative effort, and project decisions always included those safety engineers that often cause poorly planned projects to stumble. But SSOC/LATA, recognizing the value of the worker’s perspective, made overt efforts to include hourly laborers in not only the small floor-level decisions that affect them directly, but also the bigger policy questions. In this project, everyone had a voice, and thus everyone was motivated to meet the project’s difficult objectives and demanding schedules.

The deactivation of Building 886 posed many technical challenges, as do many projects in the environmental remediation and site restoration industry. But Building 886 had several special challenges, brought about by the neglected condition of the building’s systems and equipment, and by the high-pressure / low-budget atmosphere imposed by the DOE. As discussed above, the building was in an advanced state of disrepair. It had not been maintained in accordance with any sort of authorization basis (other than an expired technical operating specification that only addressed the experimental nature of the facility). In addition, the building and the HEUN systems sat undisturbed for nine years. The urgent need to remove the hazardous solution quickly imposed time limitations; there was not sufficient time to do a full characterization of the condition of the building before bidding the work and beginning the planning. Therefore, SSOC/LATA asked every member of the team to be diligent in developing contingency plans and innovative ideas. For instance, while LATA had decided to use the FL-10 containers, it had identified and secured commitments on a sufficient quantity of one liter containers, in the event of licensing problems. And the ACE process itself resulted in a multitude of other contingency plans that could be implemented in the event of an accident, spill, or other emergent condition. The return shipments of empty FL-10s that were so crucial to maintaining the packaging schedule were backed up by another transport company ready to make the shipments. Even the contractor assigned to accept, convert, and store the uranium was covered by a contingency. In all, every major undertaking by the project, and most of the minor components, were covered by two or three back-up plans. For the most part, these plans were implemented as far as was possible without incurring any significant expense. The replacement shipping containers, for example, were identified and their availability assured, but they were never purchased or on hand. In more than a few cases, however, these contingency plans were implemented, and saved the project’s schedule.

By using the key elements of a team effort, strong situational leadership, and good contingency planning, coupled with strong project management and the combined excellence of good people committed to their tasks, the SSOC/LATA team accomplished a significant risk reduction activity. The task was not easy, and many in Kaiser-Hill and the DOE doubted the project’s chances to succeed. But, teamwork and innovation served both client and contractor well, completing this high profile project several weeks ahead of schedule, and below original estimated costs.

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