ROV used in Sludge Retrieval and Treatment Project - 18575
- Orano Federal Services, LLC. (United States)
- Orano Cycle LH (France)
- Orano Projects (France)
The Orano-operated waste treatment site at La Hague, France, has treated large quantities of nuclear waste through-out its many decades of operation. During a period of over twenty years, a significant amount of the radioactive sludge resulting from the liquid waste treatment processes was placed into a set of adjoining tanks, called the STE2 silos. Now that those tanks are reaching capacity, a project has begun to retrieve this waste, transfer it to another location for homogenisation and characterization, and to then send it to another facility for conditioning and long-term storage. Because of the conditions inside and around these tanks, the waste retrieval process has many limitations. For example, the high radiation levels require that the retrieval be done efficiently, with a high removal rate and that operation be done remotely. The sludge retrieval tool will be operated and navigated while hidden inside the tank, under a significant amount of supernatant liquid, but needs to be accessible for maintenance and modifications and able to be transferred from one tank to the next. Additionally, the highly viscous consistency of the sludge requires special suction capabilities. All of these conditions need to be met, by a system that fits into the tanks' 900 mm (<3 ft) access ports. After almost three years of profound engineering, construction and testing efforts, a final design has been approved. The tool consists of a 250 kg (∼550 lb), remotely-operated vehicle (ROV) with an Archimedes-type screw attachment. It is delivered into and retrieved from the tank through a shielded glovebox that allows for maintenance and exchange of attachments. Sludge is sucked through a rotating screw and out a second tank opening with a consideration for limiting external water usage. To locate and navigate the tool, cameras detect LEDs attached to the ROV's buoys, and then calculate the ROV's position and orientation. With preliminary design and testing of the prototype complete, the project is preparing to award the ROV manufacturing contract and finalize the design of auxiliary systems, such as the rinsing and maintenance processes and localization instrumentation. After extensive final testing, the gloveboxes will be placed over the tanks in mid-2020, with entry into the first tank expected in April 2024. The ideas and experiences Orano is currently gathering during this effort will be of interest to laboratories and facilities that will soon be retrieving waste sludge from their aging storage tanks. (authors)
- Research Organization:
- WM Symposia, Inc., PO Box 27646, 85285-7646 Tempe, AZ (United States)
- OSTI ID:
- 22977833
- Report Number(s):
- INIS-US-20-WM-18575; TRN: US21V0461017878
- Resource Relation:
- Conference: WM2018: 44. Annual Waste Management Conference, Phoenix, AZ (United States), 18-22 Mar 2018; Other Information: Country of input: France; Available online at: https://www.xcdsystem.com/wmsym/2018/index.html
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
42 ENGINEERING
AREVA NC
AUXILIARY SYSTEMS
DESIGN
FASTENERS
FRANCE
GLOVEBOXES
LIQUID WASTES
MAINTENANCE
OPERATION
RADIOACTIVE WASTE PROCESSING
RADIOACTIVE WASTE STORAGE
RADIOACTIVE WASTES
REMOTE CONTROL
REMOTE HANDLING EQUIPMENT
SLUDGES
TANKS
TESTING
WASTE RETRIEVAL