Beznau Nuclear Power Plant

F1

Active reactors ( gross ):

The Beznau nuclear power plant, just KKB, located on the territory of the municipality Doettingen (Canton Aargau, Switzerland ) on an artificial island in the river Aare. It is the longest serving nuclear power plant in the world.

It consists of two identical blocks ( 1 and 2 Beznau ), which are equipped with pressurized water reactors Westinghouse per 365 MW of electrical power. Is cooled by the water of the Aare. The nuclear power plant produces about 5 billion kWh of electricity per year and supplies - with a portion of the waste heat - on the REFUNA eight surrounding communities with around 140 million kWh of district heating per year. Owned and operated by Axpo AG, Northeast Swiss to rename 2009 power stations AG ( NOK).

The NOK began in 1957 with the planning for a large power plant and decided in 1964 for the nuclear option. In 1969, after four years of construction Beznau 1 starts running. After a construction period of five years was 1972, the identical block Beznau 2 mains. The technical staff was in Böttstein Castle on the opposite side of the river Aare. Beznau 1 was the first nuclear power plant in Switzerland. Since the shutdown of the nuclear power plant in Oldbury England on February 29, 2012 There is so far ( 2013) 44 years of operation, the oldest standing operating nuclear power plant in the world.

The nuclear power plant has a permanent operating license for both units. Prerequisite for the operation remains the ongoing fulfillment of the legal, regulatory and in-house requirements for safety. The actual operation time depends on the ongoing review of safety and efficiency of the systems.

Since the commissioning of the two plants was led to increase the security of retrofits and renovations.

• Beginning and during the 1990s, among others, the steam generator, the control system of the reactor protection system were replaced, and replaced with new electronics.
• The control rooms have been adapted and installed a new turbine control system.
• For each block, a private emergency building was created. This contains additional safety systems for emergency core cooling and feeding of the steam generator and a further 50 kV emergency power train and an additional diesel generator. The safety systems in a state of emergency buildings are designed to cool down the power plant without operating crew and remedy. The buildings are particularly strong, protected from external influences, such as plane crashes, earthquakes and foreign influences.
• In the coming years, the emergency power supply is being transformed: four bunkered diesel generators are designed to provide the emergency power supply and so on from the hydraulic power plant Beznau.

Special events and faults

On July 17, 1992 died in Beznau two workers outside firms, which audit work completed in Beznau. The two workers went into the " bottom of the reactor ," a catch basin below the reactor, which in an emergency would have to absorb leaking radioactive water. There, however, the odorless noble gas argon had accumulated. The gas is heavier than air and displaces the air we breathe, which is why the workers suffocated. Other workers reported that someone should pump the pump, which would have the gas from the reactor sump, put away and used elsewhere. The two victims had this can not know. The HSK ( for the safety of Kernananlagen ) classified the fatal accident as a " non-nuclear " accident, which did not fall within its remit.

On 9 August 2007 prevented heavy rain and flood emergency power supply of the nuclear power plant by the hydroelectric plant Beznau for around 12 hours ( NOK press release ). In the power plant several additional emergency power cords are available. For a breakdown of the external power supply are bunkered, flood-proof diesel generators. Nevertheless, the Beznau must be shut down after a maximum of 24 hours of safety regulation in case of failure of the emergency power train of the hydropower plant. In the above flood event the hydroelectric plant was before this deadline in normal mode again.

On August 21, 2007 during the annual revision of Unit 2, there was another incident. The block joint reserve network feed was shut down for maintenance. To compensate for the emergency diesel generator running on full load, the block 1 has been switched on at idle. After re-establishment of the reserve network was noted that this diesel trouble caused its emergency function would not have been met. According to the authority HSK could there have existed a cross- connection to the emergency diesel from the closed block 2, this diesel is however also been in maintenance. Had a flood set as only twelve days earlier, and the hydroelectric power station had not been with enough backup power. For additional interruption of the main network KKB 1 would thus be left to prevent the meltdown only two diesel generators, each with only 50 % of the required emergency power. These or the connected emergency cooling pumps could fail due to interference at relatively short notice after switching policy.

Overall, the Beznau the federal Nuclear Regulatory had eight " incidents " report in 2007 - there has never been in a Swiss nuclear power plants in a single year many such incidents. While seven of the Beznau incidents in 2007 by the Swiss supervisory authority for nuclear installations, the HSK, as " non-safety significant incidents " were classified, they classified the above described temporary failure of the emergency power supply in August 2007 at the international event INES scale on the level 1. than disorder, that is, a deviation from the permissible areas for the safe operation of the plant

On January 31, in the morning it came to the first event in 2008: six clock it came in the reactor block 2 to an unforeseen emergency shutdown. Previously, the power of multiple gauges had failed in the main control room of the power plant. This led also to control the reactor power from used signals. This in turn led to an automatic reduction of reactor power. Therefore, the relevant personnel also reduced the turbine power. Because she lacked the necessary display information, it could not prevent even an automatic venting of steam was thrown. At 6:19 clock solved the operating personnel for security finally manually an emergency shutdown of the reactor and the system was stabilized. The defective part of the plant has been located and replaced. During the afternoon reactor could resume operation 2.

On the evening of April 10 2008, a turbine generator set has been turned off in block 2 of the Beznau nuclear power plant after the non-nuclear part of about 50 liters of oil were leaked. After the shutdown of the turbine generator set, the reactor power has been reduced by half. Oil leakage was due to a leak at the junction of an oil conduit. The repair in disconnected group lasted about twelve hours. The turbine generator set was taken on 12 April 2008 at 23:30 clock again.

On March 23, 2012 There was a leak in a pump of the primary circuit of block 2, which was then switched off. On November 21, 2012, led to a renewed rapid shutdown of Unit 2 by a defective steam generator in the non-nuclear cycle.

New Beznau III

On 4 December 2008, a general license application was submitted for the construction of a third nuclear power plant unit. At the same time a general license application for the site Muhlenberg was filed. The reactor type is a structurally identical light water reactor is provided with an output size of 1200-1600 MWe at both locations. The party and joined overarching alliance stop atomic announced immediately after the announcement of the filing of a ' facultative referendum ' against the planned buildings.

After the Fukushima nuclear disaster as a result of the Tōhoku earthquake 2011 9.0 magnitude sistierte Federal Councillor Doris Leuthard all general license applications for new nuclear power plants. So far, a seismic safety was required to magnitude 7, which were able to keep up on the power plant in Muhlenberg Bern everyone else.

Cooling ponds

The fuel storage (also wet storage ) Beznau I and II were originally 163 storage locations for fuel (enough for a Kernausladung for urgent and one years charge ) first converted into a compact storage. Here, the capacity to 340 bearings has been extended by means of the incorporation of absorber material in the storage racks.

Data of the reactor units

The Beznau nuclear power plant has a total of two blocks: