1 Copyright © 2012 by ASME EXPERIENCES GAINED DURING THE DEVELOPMENT OF THE LICENSE RENEWAL APPLICATION FOR UNIT 1 OF PAKS NPP Sandor Ratkai Head, Ageing Management Section, Nuclear Power Plant Paks Ltd. Paks, Hungary Tamas Janos Katona Scientific Adviser, Nuclear Power Plant Paks Ltd. Paks, Hungary ABSTRACT Operational license of the four VVER-440/213 units at Paks NPP, Hungary is limited to the design lifetime of 30 years. Extension by an additional 20 years of the original license is one of the main goals of the plant owner. In 2008 a programme for long-term operation (LTO) was developed and submitted to the Hungarian Atomic Energy Authority. The LTO Programme defines the activities for ensuring the extension of the operational lifetime and contains the justification of the safe LTO. The LTO Programme has to be implemented and comprehensive justification of the safe LTO has to be provided in the formal License Renewal Applications unit by unit. This work has been completed by the end of 2011, and the application has been submitted for approval for the Unit 1. The authority review and the approval of the License Renewal Application for Unit 1 should be finished before the expiration of the original design lifetime in 2012. In line with the regulations and supporting the License Renewal Application, a large number of engineering tasks have been performed. In this paper the entire project will be reported. The issues will be discussed, which have been arisen during the development of the application as well as the difficulties generated by the Hungarian technical and regulatory peculiarities will be presented. INTRODUCTION The 30 years of licensed operational term of the four units of Paks NPP is expiring, see Table 1. The preparation of the LTO at Paks NPP is almost a two decades history taking into account the firstly published paper on the subject in 1992 [2]. In 1999 the general assembly of the plant owners appointed the plant management to develop the middle term strategy of the company taking into account the evaluation of the technical, economical and legal preconditions of the potential extension of the original license, too. In 2000, a feasibility study justified that the extension of the original term could be safely extended by 20 years thanks to the good operating and maintenance practices, the robust design, good technical condition of the units and the safety upgrading measures performed during the operation [1]. The study includes the justification of the LTO from business point of view. In 2001 the owners approved the strategy of the Paks NPP consisting of two significant elements: (1) the power up rating of the reactors and (2) safe operation beyond the original design lifetime by 20 years. TABLE 1 THE LICENSED AND EXTENDED TERMS OF OPEARTION OF UNITS AT PAKS NPP Unit Start-up Design life expires Extended operating life 1 14 December 1982 2012 2032 2 26 August 1984 2014 2034 3 15 September 1986 2016 2036 4 9 August 1987 2017 2037 The preparation of the operational lifetime extension was based on parallel activities: As a first step, the environmental impact study had to be performed and the environmental licence had to be obtained for the extended time of operation. As part of this process public hearings were organized involving all stakeholders in Hungary as well as the interests in Austria, Croatia, and Romania Proceedings of the ASME 2012 Pressure Vessels & Piping Conference PVP2012 July 15-19, 2012, Toronto, Ontario, CANADA PVP2012-78852 Downloaded From: http://proceedings.asmedigitalcollection.asme.org/ on 10/14/2014 Terms of Use: http://asme.org/terms