On Site Assistance Zaporoshye NPP

The TACIS 96 programme for nuclear safety agreed upon between the European Commission and Ukraine contains provisions for operational safety and near term technical improvements for Ukrainian NPP.
In line with the programme, so called On-Site-Activities had to be implemented through cooperation between NPPs/Utilities in Ukraine and Utilities from the European Union (NPP owners-operators), in the present case through Gemeinschaftskraftwerk Neckar (GKN), a German Utility.
The related Technical Terms of Reference describe the work to be performed by the EU-Utility in the scope of this cooperation with Zaporozhye NPP.

The aim of the cooperation for the selected EU Utility was to use its experience feedback to allow the Zaporozhye NPP operator to:
• speed-up the implementation of the supply projects for which the Western Utility shall provide assistance (see 3 and C);
• benefit from the transfer of operational experience;
• manage the interface with suppliers.
During the implementation phase of the projects, the Ukrainian Counterpart defined with the Consultant ways and means to extend these on-site operational activities with the aim of supporting the Ukrainian programme to improve the operational safety of the NPPs in Ukraine

AchievementsThe following activities have been performed in providing General On-Site Assistance:
A. General On-site Assistance (Ul.03/96):
• General co-ordination of the interfaces between all on-site activities including the interfaces between the projects defined in the service contract;
• Review and assessment of the existing maintenance strategy with the aim to reduce the demand of spare parts;
• Advise for the installation measures for a prompt emptying of the turbine oil container with the aim to quickly reduce the fire hazard;
• Establishing a documentation list of valves delivered by the western supplier. Negotiations with Zaporozhye NPP of the lessons learned and drawn from me report. Comparison of the Conception for Periodic Testing for Pressurizer Safety Valves between Zaporozhye NPP and GKNII;
• Improving the Safety Culture Implementation of the Entrance Acceptance Control Procedures within the international Rules and Standards;
• Establishment of a comprehensive modernization programme containing concrete proposals, design consideration and operating aspects;
• Achieving of a mutual understanding in respect of the list of specific projects. TOR for die specific projects.
B1. Related to TACIS 1995 (U1.03/95E + U1.03/95F):
• Taking measures necessary to ensure the planned time schedule;
• Acceptance control of the delivered equipment and supervision of their implementation;
• Participation on commissioning of the installed system and training of the involved personal;
• Review of the commissioning test report;
• Supervision so that the instructions for the operating personnel be included into the operating manual;
• Final permission from the UNRA for the installation and operation of the delivered components.
B2. Hydrogen Monitoring System (Ref. U1.03/95 B):
• Detailed technical specifications;
• Preparation of tender;
• Completion of licensing process;
• Training of Zaporozhye NPP personnel;
• Installation of the H2 monitoring system;
• Acceptance test;
• Commissioning and periodic calibration of instructions.
The following tasks are also related to the TACIS 1996 programme in addition to the above mentioned activities:
C1. Safety Related Spare Parts (Ref. U1.03/96 A):
• List of spare parts needed;
• Detailed technical specifications;
• Preparation of tender;
• Acceptance control of the delivered spare parts and their implementation;
• Implementation of an entrance acceptance control in accordance with the international rules.
C2. Delivery of Test Bench for Safety Valves Adjustment (Ref. U1.03/96 B):
• Approved technical characteristics of the test bench;
• Detailed technical specifications;
• Preparation of tender;
• Delivery of the test bench for safety valves adjustment from 15 up to 400 mm nominal diameter;
• Final acceptance test;
• Training of personnel, provision of a manual and test documentation.
C3. Fire Protection Improvement for Cable Penetration (Ref. U1.03/96 C):
• Delivery of cable coating material and coating of the cables;
• Delivery of fire damper material and the assembly of these dampers by the contractor personnel. The existing dampers have been completely dismantled by plant personnel;
• Supply and erection of the required scaffolds.
C4. Mobil System for Diagnostic of Safety Related Valves (Ref. U1.03/96 Dl):
• Establishment of the technical requirements;
• Detailed technical specifications;
• Preparation of tender;
• Developed engineering procedures for the analysis of valves;
• Setting up of the equipment;
• To analyse the measured results, to process data and to identify any valve parameters outside of the normal limits.
C5. Computer Aided Testing Device for Pressurizer Safety Valves (Ref. U1.03/96 D2):
• Approved technical requirements for equipment;
• Detailed technical specifications for hardware and software;
• Preparation of tender;
• To supervise the equipment testing;
• Operating instructions;
• Engineering manual for the analysis of measurements and their results.
C6. Implementation of a Technology of Repair of WWER-1000 RPV Seal Housing (Ref. U2.03/96):
• Establishment of the technical specification for the machine-tool;
• Manufacturing and follow up the manufacturing for the machine-tool;
• Personnel training for the handling, operation and maintenance of the machine-tool;
• Preparation of instructions for personnel;
• Procurement of one seal set;
• Establishment of all necessary procedures to permit the user to realise the machining of flange-grooves and the replacement of seals;
• Development of a detailed sealing test programme for the specified and selected sealing types;
• Trail and test operation in the existing test facilities for the machining of tools;
• Sealing tests under real conditions.

The Achievements in more Detail
A. General Operational Assistance, On-site Assistance (U1.03/96)
Combine GKN-operational experience and the experience of the Zaporozhye NPP (ZNPP) to improve operational and design safety of the Zaporozhye NPP. In particular, this objective included the following main activities:
• Overall co-ordination of interfaces;
• Permanent exchange of operational experience;
• Improvement of safety culture;
• Co-ordination of training activities;
• Elaboration of the proposal in order to improve plant specific documentation (as built);
• List of the remaining, already delivered, spare parts within the TACIS 1992 and the TACIS 1993 programme;
• Comparison of the conception for periodic testing for pressurizer safety valves between the Zaporozhye NPP and GKN II;
• Documentation preparation for the valves delivered by western suppliers;
• Establishment of a comprehensive modernization programme containing concrete proposals, design consideration and operating aspects.
B1.1. Repair of Safety Valves (Ul.03/95 E)
It was necessary to repair two types of safety valves, the pressurizer and the accumulator safety valves. The valves were to be inspected regularly to guarantee the operability and capability. The inspection included training of personnel from the ZNPP as well as to establish the needed documents to perform preventive and/or predictive maintenance by the trained personnel as mentioned in the guidelines for the maintenance activities. The repair of the valves was supported by the purchase of spare parts that have replaced by new ones (like-with-like replacement). That means, the repair was strongly linked with the availability of the spare parts.
In Detail:
• Preparation of the Technical Specifications;
• Review of the contract proposal prepared by the European Commission;
• Direct agreement approval issued by the European Commission;
• Review of supplier activities during the delivery period/installation phase;
• Participation on the commissioning of the repaired safety valves and training of involved personnel concerning operability and capability of the repaired valves;
• Trouble shooting instructions;
• Periodic-recurrent-test instructions.
B1.2. Some of the safety related components of the Zaporozhye NPP were running out of the safety margin. The wear - out margin reduction had a direct influence on the safety functions of the safety related components. By means replacement without any operational interruption caused by a lack of spare parts, the time span needed from the definition of the demand to supply the spare parts should be shortened in order to avoid an operational still stand.
In Detail:
• Preparation of a list of needed spare parts;
• Establishing of the Technical Specifications;
• Substantiation for the direct agreement;
• Contracting;
• Acceptance control of the delivered spare parts and their implementation;
• Implementation of an entrance acceptance control in accordance with international standards.
B2. The installation of a hydrogen monitoring system to measure the hydrogen concentration is a first step envisaged to prevent dangerous explosive hydrogen concentration in the containment. The hydrogen mitigation concept covers all activities which are necessary to assure the integrity of the primary equipment and containment.
The installation of a hydrogen monitoring system with 14 sensors for each unit is envisaged as a first step. The hydrogen removal system will complete the hydrogen mitigation concept.
In Detail:
• Preparation of the Technical Specifications;
• Review of the tender documentation;
• Selection of the supplier;
• Contracting;
• Review of supplier activities during the delivery period/installation phase of the basic set of equipment including necessary spare parts;
• Assessment of the established specific quality assurance programme and system;
• To supervise the installation of the monitoring system;
• To participate in commissioning of the installed monitoring system and training of the entire personnel operating the system;
• Instruction for shift personnel to be included into the operating manual;
• Commissioning and periodic calibration instructions.
C1. Some of the safety related components of Zaporozhye NPP are now running out of the safety margin. The wear - out margin reduction has a direct influence on the safety functions of the safety related components. By means of a replacement without any operational interruption caused by a lack of spare parts, the time span needed from the definition of the demand to supply the spare parts should be shortened in order to avoid an operational still stand.
In Detail:
• Preparation of needed spare parts list;
• Establishing of the Technical Specifications;
• Substantiation for the direct agreement;
• Contracting;
• Acceptance control of the delivered spare parts and their implementation;
• Implementation of an entrance acceptance control in accordance with international standards.
C2. The test bench has been designed for the adjustment of safety valves from 20 up to 400 mm nominal diameter and must enable the set adjustment of safety valves from 0 up to 200 bar.
After the final acceptance, assistance for training, establishing manual and test documentation.
In Detail:
• Approval of the technical characteristics of the test bench;
• Preparation of the Technical Specifications;
• Review of the tender documentation;
• Selection of the supplier;
• Contracting;
• The test bench delivery;
• Final acceptance test;
• Development of manual and test documentation;
• Personnel training.
C3. Fire Protection Improvement for Cable Penetrations (U1.03/96C)
The cable penetrations were the weak points of the fire barriers because of their time resistance to the fire was not in accordance with the corresponding fire areas. The project consisted of upgrading these weak points by supplying the cable penetrations in accordance with the corresponding fire safety requirements. This included safety changes in consequence to the U.S. Browns Ferry cable tray fire in 1975.
In Detail:
• Establishment of the Technical Specification.Support, needed during the procurement process, including the tender process and the evaluation process;
• Required assistance for training, writing of the concerned manuals and preparation of the documentation in question.
C4. Mobile System for Diagnostic of Safety Related Valves (U1.03/96D1)
The mobile system will contribute to improving the plant safety and reliability by avoiding the need for unnecessary maintenance work. The system will also provide permanent records of the valves and actuators histories, together with a long term trend analysis. The supervision systems shall be given the guarantee for the operability and capability of electric motorised valves.
In Detail:
• Establishment of the technical requirements;
• Preparation of the Technical Specifications;
• Review of the tender documentation;
• Provision of the engineering-system-manual which describes the methods logically, including a step-by-step procedure for the analysis of valves;
• Set up operation and removal of the equipment from the place of work;
• Analysis of measured results, processing of data and identification of any valve parameters outside of the normal limits.
C5. Computer Aided Testing Device for Pressurizer Safety Valves (U1.03/96D2)
The aim of this project was to avoid the pressurizer safety valves from failing to close during the periodic tests. Such events had previously occurred in the Zaporozhye NPP and in the Kalinin NPP as well as the Balakovo NPP. In pressurized water reactors equipped with pilot operated safety valves, these safety valves, including their pilot valves, have to be tested by means of periodic inspections in order to check their safety function. The system in question is used to perform functional and adjustment tests of the pressurizer safety valves at a reduced system pressure.
In Detail:
• Approval of the technical requirements for the equipment;
• Preparation of the Technical Specifications for software and hardware;
• Review of the operating instructors;
• To supervise the equipment testing;
• Review of the operating instructors;
• Review of the engineering manual for the analysis of measurements and results

Further Information

The above mentioned Spare Parts (Section C.1) have been purchased and installed under TACIS Project U1.03/96A.