Russian expert: Reliability of Russian NPPs were checked in Spitak

"The appearance of the same situation at Russian NPPs as at Kashiwazaki-Kariwa NPP (Japan) is unlikely", - the head of Rosenergoatom PKF technical division Alexey Lopanchuk told to Russian information agency Regnum.

According to Lopanchuk, today almost all Russian NPPs are located at territories with low seismic activity, where maximum value of earthquake activity doesn't exceed 5 magnitude earthquake. Besides after Chernobyl accident it has been realized the program for in-depth assessment of safety of existing NPPs and NPPs under construction.

Additional studies for redetermination of seismic and tectonic conditions of the sites for nuclear power facilities were fulfilled and continued now. The results of these studies confirm propriety of the previous and current design decisions aimed at seismic-tectonic safety of both existing and under construction NPP units.`

Seismic resistance of NPP built by Russian projects are confirmed by the experience of earthquake happened.

Armenian NPP withstood 9 magnitude earthquake in Spitak and after in-depth study on safety assessment, it put into operation with IAEA sanction.

Besides, 5 units of Kozloduy NPP (Bulgaria) of Russian design built in different years have passed the Vranch earthquake without accidents (the focus of the earthquake was in Romania).

Lopanchuk also told about possible causes of accident at Kashiwazaki-Kariwa NPP. He pointed out that according to information available, the main seismic damage was fire at unit transformer related to fire dangerous equipment. Fires at these transformers happened not only in connection with earthquake and not only at NPP, but also at power plant of other types.

When designing NPP, risk of ignition is taken into account and special measures are envisaged for preventing fire expansion to other unit transformers.

It is obviously these measures were envisaged at Kashiwazaki-Kariwa NPP. Effective localization and suppression of fire proves this fact. In any case fire at unit transformers can't lead to radioactive releases to the environment.

As to radioactive water leakages, Lopanchuk explained that at present there is no full information to understand how radioactive water penetrated to the environment. However, the leakage estimated is 1,5 cubic meter that says about local character of accident.

According to information available, the radiation background at NPP and its surroundings doesn't exceed admissible values and there is no danger for people.

However, there is a distrustful information in mass media that a crack was formed as a result of earthquake under Kashiwazaki-Kariwa NPP. In accordance with IAEA standards and Japanese regulations and rules in the area of seismic resistance, NPP can't be located at site, under which there is any rift zone. If it is true, it is necessary to get scientific justification of information about cracks appeared and to explain their nature.

SOURCE: AtomInfo.Ru

DATE: July 26, 2007

Topics: NPP, Russia, Safety, Japan, Asia