In Chapter 64 Dr. Milan Brumovsky discusses the Czech and Slovakian Codes with respect to the Nuclear Power Plants (NPPs) Jaslovske Bohunice (440 MW) in Slovakia, Dukovany (440 MW) and Temelín (1000 MW) in the Czech Republic (both in former Czechoslovakia). Dr. Brumovsky mentions the agreement between the former Czechoslovakia and Soviet Union in context of mutual cooperation in building NPPs. The author traces the Government decisions regarding an extended project of the technical standard documentation of NPPs organized by the International Economic Association “Interatomenergo” in Moscow. The association was set up to cooperate in the field of nuclear power between individual member states of the Council of Mutual Economical Co-operation (CMEA).. The entire complex of technical standard documentation ended in 1990, when GAEN finished the whole project at international level and consequently also in the Soviet Union.
Dr. Brumovsky mentions that the fundamental problem of the project was a question of legal obligation to CMEA standards. Elaboration of obligatory position of state regulatory bodies among the members of the CMEA was done. This facilitated in determining the documentation of technical standards in the form of a legal-agreement. From the point of international relations, the procedure could be considered as sufficient; but from the standpoint of Czech NPPs, the effectiveness of utilizing these standards was at zero point, since effective steps were not organized to bring them into action. The CMEA rules resulted in merely upgrading of the Soviet rules and standards incorporated into new set of Soviet rules and standards issued around 1989. These rules and standards existed for service lifetime assessment of reactor components and were limited only to design and manufacturing; in very special cases these rules were for operation also but not from the lifetime evaluation point of view. Thus, assessment of defects, found during in-service inspection, has to be based on acceptance levels valid for manufacturing and on special procedures, prepared by the Nuclear Research Institute (NRI) Rez and manufacturers of components; for case by case application, these had to be accepted by the Czech State Office for Nuclear Safety (SONS).
SONS requirements for Lifetime Evaluation and mentions that in 1993, the SONS initiated a project “Requirements for Lifetime Evaluation of VVER Main Components” (VVER: Water—Water Energetical Reactor is of pressurized water reactor type but designed and manufactured in accordance with former Soviet codes and rules). Within the scope of this project, preparation of regulatory requirements for lifetime evaluation of reactor components, including all aspects of integrity and degrading processes of these components, was performed. Responsibility of this project was given to the NRI Rez, which focused on reactor pressure vessel (RPV) and reactor internals and issued as a SONS document with recommendations that included Operational Safety Reports. In this document, no practical procedure for lifetime evaluation was given; only general and some detailed technical requirements for evaluation of these two components were described.
Dr. Brumovsky discusses the NTD ASI Code for VVER Reactor Components. He mentions that approximately during the same time, a second activity was initiated by the Czech Association of Mechanical Engineers (ASI), which decided that a set of codes for reactor components, namely, Normative Technical Documentation (NTD) was needed for Czech nuclear industry. A plan for preparation of such codes was discussed, accepted, and put into action, details of which are presented in the chapter.
Next is a discussion of the VERLIFE PROCEDURE which is a proposal for the European Union 5th Framework Programmes that was prepared and accepted with the aim to use proposals of the Section IV as the first document to be discussed, changed, upgraded, enlarged, and finally accepted. The main goal of the project was in the preparation, evaluation, and mutual agreement of a “Unified Procedure for Lifetime Assessment of Components and Piping in VVER Type Nuclear Power Plants.” The author thereon discusses the COVERS CONTINUATION. In 2005, a new project within the EU 6th Framework Programmes was opened: COVERS—VVER Safety Research that is also coordinated by the NRI. In this project, WP 4 deals with the upgrading and updating of the VERLIFE procedure to assure that the experience obtained as well as new developments will be appropriately included in the new version. Experts from nine countries are taking part in this project, in addition to VVER-operating countries such as Czech Republic, Slovak Republic, Hungary, Finland, Spain, The Netherlands, Germany, Russia, and Ukraine, as well as from EU-JRC IE (Joint Research Center—Institute of Energy in Petten, The Netherlands) and ISTC (Institute for Scientific and Technical Cooperation).
Dr. Brumovsky concludes that The VERLIFE procedure is now fully accepted as a main regulatory document for lifetime assessment of VVER components in the Czech Republic and Slovakia and partially in Hungary and Finland. Negotiations are now in progress for its use in Ukraine and China.
The chapter has information about several manufacturing companies in the Czech Republic, Slovakia that obtained ASME Certification for manufacturing reactor (and also nonreactor components in accordance with ASME Section VIII) components for export to other countries where ASME Codes are required. The author provides References with annotated bibliography and author's publications pertinent to this chapter.
Dr. Brumovsky provides detailed information about the Structure of NTD ASI. The final version of the VERLIFE procedure in Czech was accepted as a new version of the Section IV of the NTD ASI. Czech SONS accepted NTD ASI Sections I, II, III, and IV in 2005 and recommended them for their use in the chosen safety important components in NPPs. Similarly in the Slovak Republic, Sections I and II, prepared by the Welding Institute of Slovakia in cooperation with the Welding Institute of the Czech Republic were accepted by Slovak Office for Nuclear Regulation. Structure of the Sections I, II, and III is similar to the appropriate Sections of the ASME Code Sections I, II, and III, where as the structure of Sections IV and V is fully new. The author provides detailed comparison of each of the Czech Codes with ASME B&PV Code Sections I, II, III, IV and V.
