[en] Insurers have actively contributed to the negotiations on the revision of the Vienna Convention on Civil Liability for Nuclear Damage and the Paris Convention on Third Party Liability in the Field of Nuclear Energy. In the course of these negotiations they have pointed out that some of the proposals for revision may have consequences for insurers and could prove incapable of finding insurance support. This paper aims at explaining the revision related points, which could cause problems in respect of insurability. Furthermore, the writer takes the liberty to expand its scope to more generally include developments, which have the potential to influence the availability of insurance capacity. Therefore, also the insurance implications of terrorist acts combined with share market developments of recent years will be dealt with.(author)

[en] The paper presents an overview of the IAEA safety standards including their overall structure and purpose. A detailed presentation is devoted to the general approach to safety that is embodied in the current safety requirements for the design of nuclear power plants. A safety approach is proposed for the future. This approach can be used as reference for a safe design, for safety assessment and for the preparation of the safety requirements. The method proposes an integration of deterministic and risk informed concepts in the general frame of a generalized concept of safety goals and defence in depth. This methodology may provide a useful tool for the preparation of safety requirements for the design and operation of any kind of reactor including small and medium sized reactors with innovative safety features.(author)

[en] The possible impacts of the non-uniform hydrogen distribution and the consequent fast burning should be assessed in the light of newer research information on hydrogen management. The review should include the hydrogen source term, both for the in-vessel and ex-vessel period, and investigate the potential effects on the hydrogen management strategy. NPP Krsko will repeat MAAP 4.0.5 calculation for the most important Rx vessel failure sequences taken from Individual Plant Examination Project (with molten core-concrete interaction (MCCI) and with no MCCI) including wet cavity strategy. Mass and energy gases releases of analyzed sequences will be used to assess the non-uniform hydrogen distribution and the consequent fast burning by GOTHIC 7.1 (3-D).(author)

[en] The first Romanian methodology for simultaneous environmental and human risk evaluation in case of HV installations within substations pertaining to nuclear power stations, based on EU regulation is now applicable in Cernavoda substation. High voltage substations are zones where the environmental impact is focused on electromagnetic field that's causes particular effects in living tissues (human being included). That is the reason why is necessary to identify the potential risk sources, the asses including the way to correct them and to dissimulate the results to the staff and the operational personal.(author)

[en] The risk of terrorism in the UK is not new, but since the New York World Trade Centre attacks in 2001, the potential scale of any terrorist attack has required a considerable reassessment. With UK foreign policy closely aligned to that of the USA, the UK security services now consider it is simply a matter of when and no longer if the UK is attacked. For insurers of any type this fact would cause concern; for insurers involved in high profile and potentially catastrophic loss targets such as nuclear power plants, any attack could have a severe impact on solvency and shareholder's funds. This paper's objective is to describe the terrorism insurance arrangements put in place in the U.K. both before and after the September 2001 attacks. These arrangements have been designed both to safeguard insurers' solvency and to ensure that the nuclear industry and general public can continue to be reassured by the availability of insurance should an attack ever occur.(author)

[en] Modern computer codes play an important role in nuclear safety analysis. This paper presents the investigation of a station blackout accident at a VVER 1000 NPP with the codes Relap5 mod 3.2 Scdap and Melcor 1.8.5. A special interest was taken in the hydrogen production. A large amount of hydrogen could pose a serious threat to the containment. User choices have a considerable influence on the amount of produced hydrogen. The results from the calculations are presented and discussed. The results show in general a good agreement between the calculations.(author)

[en] The development of human civilization in general as well as that of every country in particular is in direct relation to the assurance of a cost effective energy balance encompassing all industrial spheres and everyday activities. Unfortunately, the uncontrolled utilization of Earth's energy resources is already causing irreversible damage to various components of the eco-system of the Earth. Nuclear energy used for electricity and hydrogen production has the biggest technological potential for solving of the main energy outstanding issues of the new century: increasing of energy dependence; global warming. Because of good market position the political basis is assured for fast development of new generation nuclear reactors and fuel cycles which can satisfy vigorously increasing needs of affordable and clean energy. Political conditions are created for adequate participation of nuclear energy in the future global energy mix. They must give chance to the nuclear industry to take adequate part in the new energy generation capacity.(author)

[en] This paper reports the using of the PARET computer code for determining the response of the Tehran Research Reactor (TRR) upgraded core to the ramp reactivity insertion of USD1.5/0.5s. This ramp reactivity insertion has been analyzed in two; without any scram and with an overpower scram conditions. The results show that the maximum clad surface temperature during this reactivity insertion without any scram is increased up to 248 C. This value is adequately below the melting point of aluminum alloy (630 C). Therefore, the upgraded core of TRR shows a margin of about 382 C for the reactivity insertion accident of USD1.5/0.5s.(author)

[en] The paper describes work performed for the Nuclear Power Station (NPS). Work is related to the periodic initiating events frequency update for the Probabilistic Safety Assessment (PSA). Data for all relevant NPS initiating events (IE) were reviewed. The main focus was on events occurring during most recent operating history (i.e., last four years). The final IE frequencies were estimated by incorporating both NPS experience and nuclear industry experience. Each event was categorized according to NPS individual plant examination (IPE) initiating events grouping approach. For the majority of the IE groups, few, or no events have occurred at the NPS. For those IE groups with few or no NPS events, the final estimate was made by means of a Bayesian update with general nuclear industry values. Exceptions are rare loss-of-coolant-accidents (LOCA) events, where evaluation of engineering aspects is used in order to determine frequency.(author)

[en] A new reactor burnup strategy CANDLE (Constant Axial shape of Neutron flux, nuclide densities and power shape During Life of Energy producing reactor) was proposed, where shapes of neutron flux, nuclide densities and power density distributions remain constant but move to an axial direction. An equilibrium state was obtained for a large fast reactor (core radius is 2 m and reflector thickness is 0.5 m) successfully by using a newly developed direct analysis code. However, it is difficult to apply this burnup strategy to small reactors, since its neutron leakage becomes large and neutron economy becomes worse. Fuel enrichment should be increased in order to sustain the criticality. However, higher enrichment of fresh fuel makes the CANDLE burnup difficult. We try to find some small reactor designs, which can realize the CANDLE burnup. We have successfully find a design, which is not the CANDLE burnup in the strict meaning, but satisfies qualitatively its characteristics mentioned at the top of this abstract. In the final paper, the general description of CANDLE burnup and some results on the obtained small fast reactor design are presented.(author)