EX-SITU LARGE-BORE PIPE DECONTAMINATION AND CHARACTERIZATION SYSTEM

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1 EX-SITU LARGE-BORE PIPE DECONTAMINATION AND CHARACTERIZATION SYSTEM Leonel E. Lagos Hemispheric Center for Environmental Technology Florida International University West Flagler Street Miami, Fl (305) ABSTRACT Jose M. Varona Hemispheric Center for Environmental Technology Florida International University West Flagler Street Miami, Fl (305) Richard Musgrove Hemispheric Center for Environmental Technology Florida International University West Flagler Street Miami, Fl (305) The purpose of this study is to design and fabricate a system to decontaminate and characterize the internal and external surfaces of large-bore pipe. The treatment of radioactively contaminated pipe is a concern during the deactivation and decommissioning (D&D) process. As buildings undergo D&D, miles of pipe contaminated with radionuclides must be decontaminated before final disposal. To reduce the risks to the environment and human health and to support Environmental Management objectives, an innovative technology able to perform the internal and external decontamination and characterization of radiologically contaminated large bore pipe will be developed at the Hemispheric Center for Environmental Technology (HCET) at Florida International University (FIU). I. INTRODUCTION The deactivation and decommissioning of 10,000 buildings in the U.S. Department of Energy (DOE) complex will require the disposition of miles of pipe. In particular, the disposition of large-bore pipe presents difficulties in the areas of decontamination and characterization. This pipe is potentially contaminated internally as well as externally. This situation requires a system capable of decontaminating and characterizing both the internal and external surfaces of the pipe. Current decontamination and characterization systems are not designed for application to large-bore pipe. This makes direct disposal of the piping systems a necessity. Once disposed, the pipe often creates voids in the disposal cell, requiring the pipe to be cut in half or filled with a grout material. These methods are labor-intensive and costly to perform on large volumes of pipe. Direct disposal does not take advantage of recycling, which would provide monetary dividends as a result of the disposition of large-bore pipe. FIU-HCET has developed a large-bore pipe system that provides relief to this problem. This multi-level system is separated into decontamination, ventilation, characterization, and off-loading units that can decontaminate, characterize, and segregate piping and structural steel with little or no human interaction. II. ENGINEERING STUDY APPROACH A. Project Objective The overall objective of this project was to fabricate and test an innovative technology for the purpose of characterizing and decontaminating large-bore pipe for use in reducing the cost to perform decontamination and safe disposal operations. The sub-objectives required to meet the overall objective included the following: Design and fabricate a characterization system to detect and measure contamination in large-bore pipe. Design and fabricate a decontamination system for internal and external pipe surfaces. Design and fabricate an off-loading system to segregate pipe. Integrate and assess the system for commercial application. Deploy the system throughout the DOE complex.

2 B. Project Outline and Scope The project calls for a field-mobile system that can be fabricated and tested for the decontamination and characterization of large-bore pipe. The pipe when removed from a building will be cut to ten foot lengths and be free of any obstructions for processing through the system. Pipe ranging from six inches to twenty-four inches in diameter will be processed by the system. Production rates for the six-inch diameter pipe are between 3-5 feet per minute. The system is transported to a remediation site in multiple certified radioactive shipping containers. The equipment is modular and requires minimal set-up at the remediation site. Standard mobile utility sources are used to power the system. Carbon steel pipe will be at a near white metal finish when it exits the decontamination system. This surface finish will ensure all paint, rust, and dirt is removed from the pipe, simplifying the characterization process. The characterization system will meet the requirements of DOE Order and Regulatory Guide 1.86 to enable the pipe to be free-released, if the contamination levels of the pipe are below the free-release criteria. The off-loading unit will segregate pipe by final level of contamination. If the pipe has not reached free-release levels, the unit will kick the pipe onto a platform that will hold all contaminated pipes. If free-release levels have been reached, the pipe will be kicked onto a platform for clean pipes on the other side of the unit. The system will be transferred to industry for implementation at the DOE sites. C. Conceptual Design and Layout Figure 1 represents a top view of the large-bore pipe system.. 8' wide x 10' high x 38' long Strong Tight Container Ventilation System Module Air Flow Air Flow 8' wide x 10' high x 40' long Strong Tight Container 8' wide x 8' high x 20' long Strong Tight Container Pipe for Free Release Material flow Belt Conveyor Contaminated Pipe Grit Blasting Module Centrifugal Wheel for Exterior Surfaces and Compressed air nozzle for interior surfaces of the pipe. Characterization Module System characterizes the interior and exterior of the pipe in a single step. D. Selection of Decontamination Technology During FY97, an extensive search for decontamination technologies was conducted. Several sources were utilized, including Remedial Action Program Information Center (RAPIC), FIU-HCET databases for information technologies, and others. Eight technologies were short-listed based on Removal capabilities Production rates Cost information Waste generation Health & Safety.

3 Based on the above criteria, the decontamination unit selected is a remotely operated grit-blasting unit. This unit is designed in two separately functional areas: pipe internal system and pipe external system. Through the use of four 15hp gear-driven motors, the pipe external system uses centrifugal force to blast the outer surface of piping to a near-white metal finish. These motors are placed equidistant from one another in the blasting chamber to ensure an even distribution of grit on the external surface of the pipe. The pipe internal unit is composed of a pipe rotation mechanism and a blast lance. Once the pipe has exited the outer surface-blasting chamber, a hydraulic pump raises it. At this time the pipe rotation mechanism begins to turn the pipe. As the pipe is turning, the grit-releasing lance is introduced into the pipe with the help of a 0.05-hp AC motor. The lance releases steel grit, thereby blasting clean the internal surface of the pipe. The decontamination system layout is shown in Figure 2. E. Selection of Characterization Technology Fig 2 Decontamination system During FY98, a complete assessment of commercial radiological characterization technologies appropriate for combination with decontamination equipment was completed. Over the past years, this assessment was interpreted in light of lessons learned from previous attempts to integrate decontamination and characterization systems. The result is the creation of a modular design, adaptable to a wide variety of decontamination vehicles and specific contamination. Selection criteria for components and design included the following: Reliability Simplicity of use/operator affability Simplicity of maintenance (including decontamination) Interchangeability of detector transducers. The final product is composed of 4 BEGe detectors that can easily detect the free-release levels of reactor contaminants, such as U-238, Th-228 and Th-232, Cs-137, Co-60, both on external and internal surfaces. The system is designed for x-gamma detection. The measurement time is short (0.5 min) and through-put rates vary from 6.5 ft/min to 1.72 ft/min for pipe of bores sizes varying from 6" to 24". It can also measure pipes of all thicknesses (commercially available).

4 III. SAMPLING AND ANALYSIS A. Surrogate Selection, Preparation, and Technology Testing After the system was developed, a technology demonstration was held at the technology assessment site at FIU- HCET and will be held at an approved DOE facility. The test surrogates will include coating removal from internal and external surfaces of pipe of various sizes. Figure 3 shows the large-bore pipe decontamination system at FIU-HCET's testing area. The system was tested and troubleshot at FIU-HCET. This system was tested using 6", 12", and 24" schedule 40 carbon steel pipe. Some of the pipe had a 3-mil thick coating to test the blasting power of the decontamination system. Fig 3 LBP system A tent will be set up to close off the unit from free air. This tent will serve as a containment unit to prevent release of airborne particles. Performance and cost data information will be collected from the field testing. More time studies will also be conducted to collect some of the operational data. The final specifications will be compared to those set in the specification sheet at the time of the conceptual design. Field measurements will be taken to document secondary waste generation, potential personnel exposure, and other measurable data requirements. The collected data will be evaluated in order to identify performance characteristics of the developed integrated system. IV. RESULTS Preliminary tests conducted at FIU-HCET gave excellent results for the characterization unit. Table 1 lists measured activity from tests conducted using point sources.

5 Nuclide Eu- 152 Cs- 137 Cs- 137 Co-60 Co- 60* Co- 60* FIU- HCET ID # Certificate Activity (decay corrected) µci Average Detected Activity µci Check Source Table 1. Nuclide list and activity for 8-inch schedule 40 carbon steel pipe The decontamination unit also gave good results in blasting 6" and 24" pipe. Table 2 lists some of the performance data after the testing of the decontamination system. Pipe Diameter External Removal Rate Internal Removal Rate Total Removal Rate 6" ft 2 /hr. (at a pipe feed rate of 3 ft/min) 24.5 ft 2 /hr. (at a lance feed rate of 10 in/min) 45.2 ft 2 /hr. 24" ft 2 /hr. (at a pipe feed rate of 1.62 ft/min) 83.4 ft 2 /hr. (at a lance feed rate of 2.7 in/min) ft 2 /hr. Table 2. Production rates for the decontamination system V. CONCLUSIONS FIU-HCET will assess the performance of the system at Big Rock Point, Michigan, where it will be used to characterize five tons of pipe ranging in diameter from 6 to 24 inches with Cesium-137 and Cobalt-60 in the spring of Remediation service companies and Department of Energy representatives will be invited when the system is tested to solicit input and to gain an understanding of the capabilities of the system. Following the demonstration, an Innovative Technology Summary Report (ITSR) will be prepared and will contain general information as well as performance data on the Ex-Situ Large-Bore Pipe Decontamination System.

6 ACKNOWLEDGMENTS This report is based on work supported by the U.S. Department of Energy, Office of Environmental Management, Office of Science and Technology s Deactivation and Decommissioning Focus Area, Federal Energy Technology Center. FIU-HCET would like to thank Dr. Paul Hart for providing us with the opportunity and support to work on this project. REFERENCES 1. M. A. Ebadian, L. E. Lagos, Analysis of Potential Surface Blasting Decontamination Technologies for Structural Steel, Final Report, Hemispheric Center for Environmental Technology (1995). 2. U.S. Department of Energy, Radiation Protection of the Public and the Environment, DOE Order , Office of Environment, Safety and Health, Washington, D.C. (1990).

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