Final reports on the PMK-2 projects for VVER Safety Studies

Volume I of the Final Report on the PMK-2 Projects was published in 2007 by the Akadémiai Kiadó, Budapest, with the title "Results of the Experiments Performed in the PMK-2 Facility for VVER Safety Studies", by L. Szabados, Gy. Ézsöl, L. Perneczky, I. Tóth, ISBN 978-963-05-8461-6, 236 pages with a CD supplement, which contains the experimental results in digital form, containing 2640 files.

Volume II, Major Findings of PMK-2 Test Results and Validation of Thermohydraulic System Codes for VVER Safety Studies by L. Szabados, Gy. Ézsöl, L. Perneczky, I. Tóth, A. Guba, A. Takács and I. Trosztel, ISBN 978-963-05-8810-2, was published in 2009.

Both volumes of the Final Report are also available on CD-ROM containing a text file of the book, the CD-ROM of Volume I also contains the experimental results in digital form.

Copies of the books, including a CD-ROM can be obtained from:

Gy. Ézsöl
Atomic Energy Research Institute
Konkoly Thege Miklos u. 29-33
1525 Budapest, Pf. 49

CD-ROMs containing the text of the books and the experimental results are also available from the NEA Data Bank. To request a copy, please go to


PMK-2v1 Cover PMK-2v2 Cover

The PMK-2 facility is located at the KFKI Atomic Energy Research Institute (AEKI), Budapest, Hungary. It is a full-pressure thermo-hydraulic model of the primary and partly the secondary circuit of the Paks nuclear power plant of VVER-440/213 type. At the start-up time of 1985 PMK-2 was the first and the only integral-type facility for VVERs. It was designed and constructed to aid in the understanding of system behaviour and to provide databases for computer code validation. The PMK-2 was followed by the PACTEL facility for VVER-440 in Finland (1990) and the ISB and PSB facilities for VVER-1000 in Russia (1992 and 1998, respectively).

Since the start-up of the PMK-2 facility in 1985, altogether 55 experiments have been performed primarily in international framework with the participation of several experts from European and overseas countries to study one- and two-phase natural circulation, loss-of-coolant accidents (LOCA), special plant transients and accident management (AM) procedures. The results have been used for the validation of thermohydraulic system codes like ATHLET, CATHARE and RELAP5 for VVER applications.

A large number of integral-type tests have been performed in the past 30 years all over the world in different test facilities. In the last decade the OECD CSNI recognised that there is a tremendous danger of loosing these test results due to closing down many of these facilities, retirement of experts and changes in data storage. A huge effort was initiated in the 90s to collect the most important data included in the CSNI Integral Test Facility Validation Matrix at the NEA Data Bank - with limited success. In order to avoid this problem with respects to the PMK-2 data, the present books summarize the results and major findings of experiments.

Volume I contains the description of design features of the PMK-2 facility, modelling of the VVER-440/213 specific design solutions, controls and actions for safety systems. The 55 experiments performed cover an almost complete spectrum of design basis accidents included in the Safety Analysis Report of the Paks plant. The OECD-VVER cross reference matrices are developed for the PMK-2 tests for large breaks, small and intermediate leaks and transients, providing internationally accepted methodology for the identification of major phenomena addressed by the tests.

Volume II provides the identification and discussion of major findings of experiments, in terms of the OECD-VVER code validation matrices. It also presents the validation results of different versions of the ATHLET, CATHARE and RELAP5 codes applied to safety assessments in Hungary. The validation covers both the conventional qualitative method and a quantitative method based on fast Fourier transform.

The PMK-2 database has a significant value for the safety evaluation of the VVER-440/213 type reactors in operation. The database provides a valuable source of scientific information to the nuclear community in the world. The 20 year operational period established an international scientific school for experts of 29 countries participating in the PMK-2 projects.

Last updated: 25 March 2015