Since 1996 the Ukrainian regulatory authorities have been supported by the EU TSO through different EBRD and TACIS projects related to evaluation of the Modernisation Programme proposed by the Utility. One of the main results of such assistance was the enhancement of the initially proposed Modernisation Programme by additional measures. The Tacis funded project UK/TS/23 has provided support for the Licensing related assessment of on-site safety assistance projects, project implementation planning (PIP) in South Ukraine. In particular it has provided technical support to SNRCU in licensing related assessments of implementation by means of measures concerning the replacement of safety related Boron Concentration Measurement Systems (BCMS) as well as safety related Data Acquisition and Processing Systems (DAPS). Both replacements aim at improving the safety functions of the installation and the safety of the operation.
The main objective of this licensing assistance project consisted in providing technical support to SNRCU in licensing related assessments of improvement measures to be implemented in South Ukraine under the planned Tacis funded on-site assistance (OSA) Project Implementation Phase (PIP), titled ‘’ PIP “BORON CONCENTRATION CONTROL SYSTEM (BCMS) and DATA ACQUISITION AND PROCESSING SYSTEM (DAPS)’’ using during the implementation of so called ”2 + 2 approach” which should be understood as support given to both the operator and regulator by an EU organisation.
The plant modernizations are accompanied by a licensing process covering many nuclear licensing stages according to a licensing plan approved by SNRCU and agreed with the Utility Energoatom. The TSOs’ technical support provided under the Tacis Project UK/TS/23 to SNRCU covered the licensing steps “Decision on equipment mounting” and “Decision on commissioning”, which refer to approval of Terms of Reference (Technical Task) and approval of Technical Design Specifications.
First part of project was devoted to the expert review of the submitted ‘’technical design’’ documentation. It was based on Terms of Reference (TORs) which should address all aspects of modernization, technical specification and subsequent safety analysis in support of the technical design. The review of the technical design documentation as well as the documentation of the mounting and testing showed, as a general finding, that some data, conditions, assumptions in the content of the TOR were not adequately supported or justified. The applicant and suppliers were advised to request submission of a further clarification and information in order to provide evidence that the scope of modernization, the way it was implemented and related impact on the affected safety systems, accident analysis and operational aspects of the NPP have been adequately considered and assessed. Concerning BCMS the following main conclusions have been made:
According to used IAEA safety guides and to the safety importance of the system, the TSO expert team considers that the corresponding classification of this instrumentation must be, at least, the category B of the IEC classification instead of the proposed 3N categorization issued from the Ukrainian rules which appears to be less restrictive. For this purpose, the TSO team requests the supplier to present the needed improvements to meet the Category B classification. In the mean time, the impact of the implementation of this new instrumentation on the content of the SAR must be clearly provided.
With regards to the Factory acceptance testing programme of the Boron Concentration Measuring System, the TSO team considered that further information should be provided and the coverage of these tests. Beyond the FAT, periodic tests devoted to ensure the reliability of the boron concentration measurements after commissioning must be clearly defined.
Regarding the Quality Assurance Plan, TSO experts recall that the Quality guide of “Mostro” is unknown and not available. The findings, recommendations and remarks presented by the Western TSO team during the meeting led the TSO expert to recommend an update of this document.
Main conclusions concerning DAPS:
- The main deficit is the missing analysis of safety classification.
During the training sessions the EU as well as UA experts have learned that there are many deficits concerning the knowledge of nuclear facilities as well as regulations and assessment approaches in Ukraine as well as Western Europe. The participants welcomed the training which gave them opportunity to improve their knowledge.
(Quality of the results, Lesson learned, Recommendations for follow-up)
The EU TSO reviewed the NAEK upgrading programme against the VVER IAEA issue books through the examination of these documents and were not able to decide if the three types of Ukrainian VVER NPPs reach the IAEA safety standards. Therefore the EU TSO recommends checking the real state in the plants with the IAEA SAFETY ISSUE BOOKS RECOMMENDATIONS.