Background

The TACIS programmes for Nuclear Safety agreed upon between the European Commission and the relevant authorities of beneficiary states contained provisions for on-site assistance (OSA).

The general objective of the on-site assistance was to combine the experience of TVONS as the Contractor (EU Utility) with the experience and needs of the Novovoronezh NPP, with the goal to improve the operational safety of the NPP and to carry-out specific safety related projects, which included also equipment supplies.

The OSA at Novovoronezh NPP at the time of the present contract consisted of operational assistance activities and 11 supply projects, which continued the work carried out under the previous OSA-contract (R1.01/97) between EC and TVONS.

The OSA-part dedicated to the development/ completion of the previous TACIS modernisation projects included the following parallel projects:

• R1.01/94D Leak detection system between primary and secondary loop of VVER-440
• R1.01/96A Steam generator leak detection system for Russian VVER

The steam generators of the VVER type NPP are one of the barriers against the release of radioactivity to the environment. The leaks between the primary and secondary loops could be the result of un-tightness of the primary coolant circuit inside the steam generators. In case of a tube failure in the steam generator, N-16 and radioactive noble gases (fission products from the fuel) would flow from primary to secondary circuits of the reactor and release activity to the environment.

To protect the NPP staff, the population around and the surroundings of the plant from radiation hazards the NPP units were equipped with leak detection systems, designed to measure this leakage activity continuously under all operational circumstances by means of appropriate methods such as the spectrometric method. The measuring signals are indicated and recorded in the control room, and in case of an unacceptable leak, the operator could initiate preventive action.

Objectives

The purpose of the supply was to manufacture, to deliver, and to provide supervision of unpacking, technical supervision during installation on-site, and training, by the supplier of equipment for leak detection between the primary and secondary loops, in five lots:

R1.01/94 D

LOT 1 – contract NSP-054-KLA-005/93-94 VVER440 - 2 sets of equipment for leak detection between primary and secondary loops for Kola NPP (1 set for reference unit, one for other unit)

LOT 2 – contract NSP-030-NVV-001/95 VVER440 - 2 sets of equipment for leak detection between primary and secondary loops for two units of Novovoronezh NPP

R1.01/96 A

LOT 3 – contract NSP-029-BAL-004/96 – VVER 1000 - 4 sets of equipment for leak detection between primary and secondary loops for Balakovo NPP (1 set for the reference unit, 3 sets for the other three units)

LOT 4 – contract NSP-030-KAL-004/96 – VVER1000 - 2 sets of equipment for leak detection between primary and secondary loops for two Kalinin NPP units

LOT 5 – contract NSP-055-NVV-004/93-94 – VVER1000 - 1 set of equipment for leak detection between primary and secondary loops for one Novovoronezh NPP unit

The present contract was for Lot 5 described above.

The supplies were accompanied by spare parts and consumables for the warranty period and for 5 years of operation (in accordance with the Technical Specifications).

The main objectives of the parallel projects and tasks for the supplier were:

• detailed design (pilot project) of a leak detection system, continuously monitoring the radioactive contents of the steam, suitable for VVER reference unit (in particular VVER 440 type and VVER1000 type NPP respectively) and adaptable for VVER type plants in general
• specification and supply of the monitoring system equipment for specified units
• installation, commissioning and acceptance tests of the system at sites in co-operation with the end-user and the local subcontractor
• providing of relevant documentation (system description, equipment specifications, test programs and manuals)
• supply of the equipment for the remaining units
• education and know-how transfer, for the reference unit personnel to be able to operate, calibrate and maintain the systems at the reference plant with the technical supervision of the supplier and to be able to realize such leak detection monitoring systems at the remaining VVER type NPP (VVER 440 type NPP and VVER1000 type respectively).

Project Results

According to the meeting decision between representatives of Russian NPP on TACIS projects in Moscow in 01.09.2000, the projects R1.01/94-D and R1.01/96-A were handled together.

The projects provided primary- to secondary leak detection in the steam generators by monitoring the N-16 volumetric activity in the live steam at the steam generator outlet (for VVER NPP). The system ensured a leak measuring range from 0,5 kg/h to 5000 kg/h at full reactor power with a delay of maximum 100 seconds for each steam generator (the leak detection error was defined during the final calibration of the measuring channels).

Initially Kola NPP was the leading NPP, responsible from the Russian side for implementation, but after REA decision in July 2001, each NPP had to receive separately the delivery and perform the custom clearance procedures. REA had the responsibility for the correctness of the technical specifications made by sub-contractor and provided coordination.

The contractor performed the work in partnership with the Benefiaciary (Rosenergoatom), end-user (VVER NPP) and with the procurement agent (Italtrend).

The system provided measuring data from each steam generator to the computer in the radiation monitoring room (RMR) of the corresponding power plant unit. Each set of equipment for leak detection between the primary and the secondary loop included: detector units including a preamplifier and a transmitter with a power supply module; thermal protection for detector units (if necessary); lead shielding for the detector unit; subassembly (mounting) set to fix the detector at the monitoring position; transmitter units; data processing units; cable between transmitter units and data processing units; adapter/converter unit; network between the data processing units and adapter/converter unit; industrial computer.

The detailed design of the system and measuring equipment was supplied by the Contractor. As exception the auxiliary components: lead shielding of the detectors and cabling to the main control room were provided by the end user according to the contractor specification. The main work of installation, commissioning, acceptance tests and calibration was provided by the local subcontractor and the beneficiary. The realization of the project had 6 phases as follows:

• determination of the project approach
• compilation of actual as built documents necessary for the implementation of the measuring systems as the reference units
• detailed design of the measuring system and assistance for the detailed project documentation
• equipment procurement and personnel training
• implementation of the systems at sites and continuation of personnel training
• final acceptance test of the systems and final documentation

The tender dossier was endorsed on 24.07.2002. For both projects the tender was launched on 03.09.2002, and tender evaluation was done in the period 11-15.11.2002. The final decision about supplier (MGPI) was made on 31.03.2003.

For R1.01/94D, the contract implementation took place between 30.10.2003 (date of signature for the contracts) until the end of 2004.

Due to the need for extra equipment (additional cables) the EC agreed to provide additional funding on 25.06.2003, and the equipment was included in the contract signed on 30.10.2003.

At MPGI premises the Factory Acceptance Testing (FAT) was performed on 01-05.03.2004, with the participation of Rosenergoatom.

For R1.01/96A, the contract implementation started on 30.10.2003 and the provisional acceptance was on 12.04.2004.
The warranty period was one year for each project.

The End User’s staff was trained in the commissioning, operation, maintenance and repair of the supplied equipment. At the reference NPP unit training was carried out by Supplier’s staff, at the other NPP units was carried out by Supplier with the support of the Local Subcontractor.

The Certificate of compliance with the Russian safety standards, issued by Gosstandard RF (or its agents in some countries), was necessary for the import of the equipment into the Russian Federation. Materials and equipments, their engineering and design, manufacture and tests had to meet requirements and criteria of the Russian codes and standards as well as Western codes and standards applicable in Russia. Factory acceptance tests were mandatory and were carried out according to the Factory inspections and test plan and the Supplier’s testing procedures approved by the reference NPP. All equipments were manufactured, inspected and tested according to a specified Quality Assurance plan. All items of delivery were subject to an arrival quality control performed by the End User’s staff as per general requirements of End User’s instructions for arrival inspection.