Since July 1998,
the safety of NPP V-1 units has been subject to review by the following external missions:
Mission of the World Association of
Nuclear Operators - WANO Peer Review to NPP Bohunice V-1 on 19 October - 6 November 1998.
International experts identified 14 areas for improvement and also 9 strengths, i.e. areas
that may serve as a good practice to other power plants.
Repeated IAEA Mission - Assessment of
seismic data (SIDAM) for the Nuclear Power Plants Bohunice and Mochovce, on 16 November -
20 November 1998. The aim of the mission was to review the method of the evaluation of the
seismic input data and evaluation of the safety impacts of external earthquake hazards.
The team assessed the background documents presented and compared them with the
recommendations of the IAEA safety guideline 50 - SG - S1, related the location of NPPs.
Achieved results were concluded as being satisfactory completed.
Visit of a IAEA expert group to review
the preparedness for the Project Y2K (the year 2000), on 26-28 April 1999. The team
appreciated the extent and the appropriateness of SE, a.s.´s strategy of the approach to
the problem of the year 2000. The team also provided some recommendations and suggestions
to improve the Y2K programme, in particular related to the identification of problem areas
and elements, frequencies of monitoring of the progress by the management, system testing,
external factors, cooperation with external partners, etc.
IAEA “Follow-up Review Mission on
Seismic Capacity and Upgrading of Bohunice V-1 NPP” took place on 1 - 8 September 1999.
The Mission represented a follow-up of the Mission that visited the NPP in July 1994, and
assessed the NPP V-1 seismic reinforcement program that had been part of the extensive
upgrading program of NPP V-1. The assessment was mainly focused on the documentation
related to organization of reinforcement program and to general criteria of seismic
resistance as well. The Mission concluded that all measures related to NPP V-1 seismic
reinforcement were in accordance with the approaches used by NPPs Paks and Mochovce. This
fact confirms the reliability of the entire programme. The facts commented upon by the
Mission did not cast any doubts on the overall concept of the improvement programme, and
did not introduce any changes into the structural works performed.
Also, the Mission completed the Technical Guideline Document for seismic evaluation of NPP
WENRA Task Force Mission to NPP V-1 took
place on 12-15 October 1999 at Jaslovské Bohunice and on 15 October 1999 at ÚJD. The
Mission focused on completion of information for the WENRA review report on the status of
nuclear safety in countries applying to join the EU, of March 1999, adding information
concerning WWER-440/V-230 units. The “Western European Nuclear Regulators` Association
Report on Tasks Force Mission to Bohunice and Kozloduj Nuclear Power Plants (February
2000)” stated, a.o., “…significant improvements to reactor safety. A concern remains
about the ability of the confinement to cope with the failure of a large primary circuit
pipe work. If a solution can be found to this issue, the plant should reach a safety level
comparable to that of Western European reactors of the same vintage. “
IAEA Mission to Review the Results of the
Gradual Upgrading at Bohunice WWER-440/230 NPP Units 1 and 2 (20-24 November 2000). The
IAEA Mission took place based on ÚJD´s request secondary to Slovak Government’s
Resolution No. 302/1999 of 21 April 1999. The Mission’s objective was to review the
outcome of the gradual upgrading (reconstruction ), in particular whether the measures
taken have been sufficiently oriented towards the relevant areas. Moreover, the mission
obtained an overall picture of the safety improvement of the power plant through improving
the efficiency of the main safety functions under operating and emergency conditions. The
experts also evaluated the improved defense-in-depth concept of the power plant which
defines a new safety case. In addition to the evaluation of the gradual upgrading project,
the experts also verified the operational safety. In both areas NPP V-1 recorded an
appropriate progress, as reflected in the achievement of balanced NPP´s security and
safety precautions. In their conclusions, the Mission stated: “…..The programme
defines a new safety case (new design basis) which satisfies the Slovak National
Requirements and goes in some areas beyond the IAEA recommendations for safety upgrading
of WWER440/230 NPPs. ….In conclusion, all safety issues identified earlier by the IAEA
have been appropriately addressed. Further work on safety is a continuous process which is
needed to maintain a high level of safety. “ Also, the Mission made some additional
(supplementary) recommendations, such as completion of PSA for low power, accident
management and severe accident mitigation programme, that go beyond the original
recommendations of IAEA; they however represent recent development trends in the area of