Background

The Smolensk Nuclear Power Plant (SmNPP), located in the Smolensk region of Russia, comprises 3 power units. The site lies 3 km away from the nearby town of Desnogorsk on the bank of an artificial lake situated on the river Desna. Unit 1 was commissioned in 1982, Unit 2 in 1985 and Unit 3 in 1990. All three units have reactors of the RBMK-1000 boiling water graphite moderated type and were still in operation at the time of this contract.

In the early days of the TACIS Nuclear Safety assistance programme, Non-Destructive Testing (NDT) of reactor circuit components had been recognised as a priority area requiring urgent improvement in the Russian Federation. This applied at both VVER and RBMK NPPs. NDT provides a line of defence against failure of safety relevant equipment and components and is a highly important part of an in-service inspection (ISI) programme at NPPs. At RBMK NPPs, improvements were required to NDT techniques to contribute to the assurance of fuel channel integrity and to the prevention of failure of critical components.

In the framework of the TACIS 1994 Nuclear Safety Programme, the European Commission and SmNPP agreed on a project to procure advanced NDT equipment for use in ISI of primary circuit components.

Objective

The objective of the project was the provision of three modern NDT systems (3 lots) for in-service inspection of equipment and components of Smolensk NPP:

1. An automated and semi-automated in-service inspection system for ultrasonic inspection of the steam drum separators, the collectors and connecting primary pipework of 800mm diameter. The scope comprised one set of equipment including:

• A scanner;
• Ultrasonic probes, spares and other items;
• Handling equipment;
• Data acquisition, analysis and display systems including software, and a colour screen for viewing inspection data/results;
• Equipment for calibration including suitable calibration blocks for straight (0 deg.) and angle beam examination;
• The necessary cabling and cable management system, and including telephone intercom system between inspection head and control positions;
• Spare parts, consumables and tools for maintenance;
• A storage cabinet for the long term storage of the complete set of equipment including cables;
• A data storage system to accommodate long term storage of significant inspection information.

2. In-service inspection equipment for remote inspection of the reactor channels by ultrasonic, eddy current and video inspection devices. The scope comprised one set of equipment including:

• A probe head or heads with suitable ultrasonic and eddy current transducers and video camera;
• A spare head or heads and spare video camera;
• A hoisting device for positioning the probe head to a known and reproducible location;
• Connecting cabling and cable management system;
• A remote control unit for automatic operations with 50 m of cabling;
• Telephone intercom system between the station on the pilecap and the control unit;
• A data analysis and display system including data processor, colour screen for viewing inspection data and results, and a colour printer for hardcopy output of the data and results;
• Recording equipment for the video data, including video cassettes;
• Equipment for calibration including suitable calibration blocks;
• Spare parts and tools for maintenance.

3. In-service inspection equipment to perform volumetric inspection of the upper weld and associated steel tubing in the reactor channels. This comprised equipment to perform ultrasonic inspection as well as ancillary equipment required to enable existing SmNPP radiographic inspection devices to be employed. The scope comprised five sets of equipment including:

For each ultrasonic unit:

• A scanning unit, with ultrasonic probes, capable of achieving the required locational accuracy;
• Spare probes, according to lifetime;
• Connecting cabling and cable management system;
• Telephone intercom system between stations;
• A remote control unit for automatic operation;
• Local control of the scanner;
• A data acquisition and analysis system including data processor, colour screen for viewing inspection data and results, and a colour printer for hardcopy output of the data and results;
• Equipment for calibration including suitable calibration blocks;
• Spare parts and tools for maintenance;
• Equipment for recording the data onto a magnetic disc;
• Remote controlled equipment for preparing the surfaces to be inspected prior to inspection.

For the radiographic ancillary items:

• A device to locate the existing source inside the tubes at required height;
• A device to attach film around the tube.

The scope of work/supplies included the design, purchasing of sub-supplies, manufacture, testing, packing, transport, supervision of installation and commissioning, documentation, training of the End User's personnel in the operation and maintenance of the equipment.

In the TACIS 1996 programme, a further project was programmed to provide additional spare parts and additional training of the End User's personnel in the operation of the above equipment (project R1.05/96B1).

Results

The contract was signed on 22 December 1999. After significant delays and disputes between the parties, the equipment was tested at the supplier's premises in August 2003. Further delays occurred before the equipment was delivered to site, cleared through the customs import procedures, installed and tested. Site Acceptance Tests of the equipment (all 3 lots) were completed during the period 24 to 31 October 2006. The Provisional and Final Acceptance Certificates were issued on 2 November 2006.