Presentation on theme: "RWE NUKEM The Design, Construction and Operation of NORM Descaling Plants E Taylor and L Fellingham."— Presentation transcript:
RWE NUKEM The Design, Construction and Operation of NORM Descaling Plants E Taylor and L Fellingham
RWE NUKEM 2 Structure of the Presentation Background to the Problem of NORM Contamination Potential Solutions De-scaling Techniques Design of Plants Examples of Operational Plant Safety Assessment Waste Management Concepts for Next Generation Plant Conclusions
RWE NUKEM 3 Nature of the Problem Around the world there are significant arisings of NORM- contaminated plant being generated by the oil & gas industry Much of this is stored in open yards There is a potential contamination threat to workers and a long-term environmental liability
RWE NUKEM 4 NORM-contaminated Equipment
RWE NUKEM 5 Required Solution Manage NORM wastes in accordance with best international practice Reduce the volume of NORM-contaminated waste arisings Concentrate the radioactivity into the minimum practical volume Store the concentrated activity safely Reuse or recycle as much of the contaminated equipment, etc, as possible.
RWE NUKEM 6 RWE NUKEM’s Experience of providing Solutions Design, construction and initial operation of the Al-Furat Petroleum Company (AFPC) facility in Syria Design, construction and operation of the NORM facility at the Dounreay site serving the North Sea oilfields (now closed) Design, construction and operation of a modular facility at the Winfrith site to meet the requirements of the Wytch Farm oilfield operated by BP
RWE NUKEM 7 The Facilities
RWE NUKEM 8 Techniques evaluated for removing Scale and Sludge from contaminated Equipment Proprietary and developmental stage, chemical descaling methods Various forms of particle blasting using sand, ballotini, metal shot, solid CO 2, etc; Abrasion techniques using wire and other forms of brushes; and High pressure jetting techniques, using water and other process fluids.
RWE NUKEM 9 High Pressure Water Jetting – The Optimum Choice for Descaling It is very efficient at scale removal, irrespective of the chemical and mineral form of the scale; The water is capable of penetrating into narrow crevices, cracks, corrosion pits, etc, and removing scale and other adhering deposits. Hence residual contamination levels are very low and high decontamination factors are achieved; The speed of processing is higher than with any alternatives, so reducing the necessary size of any plant; It does minimal damage to the metal surface of the components, etc, being descaled; The process makes use of the very low solubility of the scale and particularly the radium salts. The scale and radioactive contaminants are not solubilised. Hence the process water treatment is very simple involving only filtration and no chemical treatment;
RWE NUKEM 10 High Pressure Water Jetting – The Optimum Choice for Descaling (2) The process water is recycled after filtration, so enabling the minimum volume of water to be used and generating no or a minimal volume of liquid effluent; The scale can be encapsulated or re-injected with the minimum of treatment. It is compatible with hydraulic cements, making it ideal for encapsulation directly or after maceration. It can be disposed of after maceration and slurrying by reinjection into appropriate geological formations, including those exhausted of oil and gas. Left in the chemical form in which it was originally deposited, the very low solubility of the scale in aqueous environments makes it an ideal waste form for long-term storage and disposal in both near surface and geological formations.
RWE NUKEM 11 Deployment of High Pressure Water Jetting
RWE NUKEM 12 Safety Assessment of NORM Descaling Facilities Calculation of radiological doses due to routine decontamination operations for operators of the plant and an assessment for the general public. Determination of the radiological risk to both operators and the public from potential accidents arising from fault conditions. A bounding credible accident scenario, which would demonstrate that “worst case” scenarios result in negligible dose uptake by members of the workforce and general public in the surrounding areas. A review of industrial hazards
RWE NUKEM 13 Main Hazards assessed in Safety Assessment Radiological HazardsNon-Radiological Hazards (i) Loss of sludge settling tank containment.(i)Fire. (ii) The dropping of a bundle of received "dirty" tubulars within NDF and Waste Store (ii)Handling of heavy components. (iii) Failures of the ventilation system.(iii)Noise. (iv) Loss of containment(iv)Burns (v)High Pressure Jets (vi)Legionella (vii)Slips, trips and falls (viii)Fume emission from oxy-propane cutting (ix)Loss of breathing air (x) External events
RWE NUKEM 14 Typical Results of Radiological Safety Assessments FaultDose to Operator ( Sv) Dose to Public ( Sv) Minor Tank Failure13.5Negligible Major Tank FailureNegligible Dropping of a Bundle of Tubulars Negligible Ventilation System Fan Failure 7.5Negligible Ventilation System HEPA Filter Failure -Negligible Dropped Drum0.34Negligible Aircraft Crash-1.36
RWE NUKEM 15 Design Concept for Plants A high proportion of the equipment to be descaled is in the form of tubulars with a much smaller proportion in the form of valves, Christmas trees, heaters, treaters, separators, pumps, meters, dehydrators, salt water tanks, etc. The tubulars are uniform geometry items, differing only in length and diameter. The other equipment comes in a very diverse range of shapes and sizes, making process automation much more difficult without complex equipment. Treat these as two distinct streams. In order to achieve high throughputs and to process the much higher quantities, use a semi-automated approach for tubular de-scaling where possible. Use manual descaling with dismantlement and potentially cutting to expose internal surfaces for other equipment.
RWE NUKEM 16 Examples of Plant Design NORM facility at Dounreay Al-Furat Petroleum Company (AFPC) NORM facility in Syria The modular NORM Decontamination Facility at Winfrith operated for BP
RWE NUKEM 17 The NORM Descaling Plant at Dounreay
RWE NUKEM 18 Tubular Monitoring in the NORM Descaling Plant at Dounreay
RWE NUKEM 19 Equipment Descaling in the NORM Descaling Plant at Dounreay
RWE NUKEM 20 A View of the Front of the Al-Furat Petroleum Company (AFPC) facility in Syria
RWE NUKEM 21 The Burning Bay/Stripdown Area
RWE NUKEM 22 Tubular Descaling Unit in the NDF Plant
RWE NUKEM 23 The Liquid Effluent Settling Tanks in the NDF
RWE NUKEM 24 The Winfrith NORM Decontamination Facility
RWE NUKEM 25 The Winfrith NORM Descaling Plant Tubular Receipt Area
RWE NUKEM 26 The Winfrith NORM Descaling Plant Tubular Descaling Area
RWE NUKEM 27 The Winfrith NORM Descaling Plant Skid Mounted Pump and Extract System
RWE NUKEM 28 The Management of the Residual Radioactive Waste Options –Storage on-site –Use of National Repository Facilities –Dedicated long term safe storage –Re-injection
RWE NUKEM 29 View of the Interior of a Dedicated Waste Store
RWE NUKEM NORM Descaling Plants – The Next Generation
RWE NUKEM 31 Modular Descaling Facility using ModuCon Units – Fixed Unit (1)
RWE NUKEM 32 Modular Descaling Facility using ModuCon Units – Fixed Unit (2)
RWE NUKEM 33 Modular Descaling Facility using ModuCon Units – Field Transportable Unit (1)
RWE NUKEM 34 Modular Descaling Facility using ModuCon Units – Field Transportable Unit (2)
RWE NUKEM 35 Conclusions There is now considerable design and operational experience of NORM de-scaling plants Techniques for de-scaling have also been extensively developed Waste management is an ongoing issue New designs of plant using modular approaches could be more cost effective.