The ULBA Low Enriched Uranium Conversion and Fuel Fabrication Plant (or ULBA Metallurgy Plant - UMP) is located at Ust-Kamenogorsk on the river Ulba in North Kazakhstan. The plant was one of the largest nuclear fuel manufacturers in the world and produced fuel pellets for Russian designed RBMK and VVER reactors as well as for the world market.
The plant converted uranium hexafluoride and uranium nitrate received from Russia into uranium dioxide and sintered the material into pellets to be sold back to Russia where they were used for the manufacture of fuel rods. UMP also sold some intermediate products (like UO2 powder) to Western companies. Production capacity was 2000 t/y of pellets. The units relevant for this project were:
- a chemical processing unit, to convert UF6 to UO2 powder;
- a metallurgical unit, for fabrication of pellets from the powder.
The design of the installations achieved good operational performance and criticality safety, but nuclear material accountancy within the production lines was not adequately incorporated.
After its independence in December 1991, Kazakhstan formally acceded to the Non Proliferation Treaty (NPT) in 1994 and the Safeguards Agreement with the IAEA entered into force in 1995. Obligations to be fulfilled included the introduction of instrumentation for accurate Mass/Volume determinations and for necessary Containment/Surveillance devices. The measuring systems required to establish a material control had to be such that the Material Unaccounted For (MUF) would be in the range of the International Target Values (<0.1%).
This project was part of the TACIS Programme of 1997 for nuclear safety in Kazakhstan. The project was designed to support the Kazakh beneficiary, UMP, in order to fulfil the safeguards requirements of the International Atomic Energy Agency (IAEA). The project aimed at improving the nuclear material accountancy and control (NMAC) systems at the plant. The Contractor was the Joint Research Centre (JRC) Ispra, a key actor in TACIS nuclear safety projects for NMAC.
The project comprised a service contract (this contract) with JRC Ispra and a supply contract (see project K5.01/97C) for the procurement of equipment through tendering on the open market. The service contract comprised three parts:
- Implementation of Mass/Volume (M/V) Measurement Techniques, for the improvement of the measuring accuracy of the level and density of uranium nitrate solution in tanks. The plant had a large number of tanks for storage of uranium nitrate. A total of 231 tanks had to be equipped with level and density measuring capabilities. Design of prototype measurement systems, installation, delivery of software, testing, and training were included in the scope of the contract followed by trial operation of the systems. Part of the required equipment was supplied by the Consultant as part of the service contract. The main part of the equipment was provided through the above mentioned supply contract K5.01/97C.
- Implementation of Containment/Surveillance (C/S), for improving the safeguards verification. The two components of the scope of this activity were (i) to develop and deliver a special monitoring system for storage areas of Uranium and Thorium comprising a video surveillance system, and (ii) to provide a seal verification system and metal cap seals. The related equipment was provided by the Consultant as part of the service contract.
- Technical Co-ordination, Monitoring and Procurement of equipment: The main part of equipment required for the prototype measurement systems were to be supplied through competitive tender (see project K5.01/97C ) and comprised: portable measuring systems (PMS), fixed measuring systems (FMS), unattended monitoring stations, calibration equipment and informatics hardware & software. The Consultant was required to prepare the Technical Specifications for the procurement of the equipment and coordinate and follow-up the procurement, testing and technical reception of equipment. This task also included the provision of a training programme and training of the End User for the implementation of the M/V measurement and C/S techniques as well as establishing a training facility at the plant.
The contract was signed in April 2000. Under the project, mass/volume equipment, containment/surveillance equipment and training have been provided to the ULBA Plant.
The mass-volume equipment for the project was designed by JRC, Ispra based on a multi tank scanning principle. In essence dip tubes are inserted in a tank, one above the surface one near the bottom and one at a fixed distance from the lower dip tube. A small flow of air goes through the tubes and bubbles are created at the end of the tubes which are immersed in the liquid. By doing very precise measurements of the pressure in the various tubes, the level and the density of the liquid can be determined and the volume can be derived with the tank calibration curve. All 231 tanks had to be equipped with three dip tubes.
The large number of tanks in Ulba made it necessary to connect up to 15 tanks to one measurement station, and connect one tank at a time to the measurement device by “multiplexing”. This also meant long connection tubes between the tanks and the measurement station, which caused technical difficulties, which were solved with larger diameter tubes. A total of 17 fixed measurement stations, supplied via the related supply contract (see project K5.01/97C) were installed at the plant.
The delivered containment/surveillance equipment consisted of a review station with 15 cameras for surveillance and copper brass seals with accessories. The installation and testing of the equipment was done by ULBA personnel. The cameras were conceived to resist the extreme land climate conditions of Ust-Kamenogorsk. The copper brass seals comprise two circular parts. Before installation of the seal, reference images are taken from the bottom and the cover part. During the attachment of the seal the two parts are crimped together blocking a metal wire. The verification after removal consists in opening the seal by cutting it and comparing the two parts with the previously stored reference images. Training was provided by the Consultant.
A training room was established with a prototype of the Fixed Measurement Station, a portable level measurement device, and the cutting machine for the copper brass seals. A first training was given in April 2002 in Ispra, followed by training at Ulba in the new training room in October 2002.
The contract was completed in April 2004.