Temporary Shutdown at unit Oskarshamn 3 for the Purpose of Replacing a Fuel Assembly

Pressrelease Friday, November 20, 2015

The production at unit Oskarshamn 3 (O3) will be temporarily shut down on Saturday 21 November due to a damaged fuel assembly that must be replaced. The time required to complete the measure has been estimated at eight days and the intention is to have the reactor in operation again on 29 November.

In the reactor core at unit O3, there are a total of 700 fuel assemblies and each fuel assembly contains 100 fuel cladding tubes encasing the uranium. The water constantly flowing through the core in the reactor vessel should be absolutely clean, but there may be small particles at times. These particles may stick to the cladding tubes and cause abrasion, or so called fuel damage.

Fuel damages are not uncommon, they do occur a few times every year at the Swedish nuclear power plants. Historically, a number of fuel damages have occurred at unit O3, the latest occurrence taking place in 2012, but this is becoming increasingly infrequent by means of measures taken such as training and improvements in the facilities.

However, fuel damage has now been detected at unit O3 and thus the production will be temporarily shut down on 21 November for the purpose of performing leak detection and replacing the defective fuel assembly. Other maintenance measures will also be taken, which are not possible to perform during operation. The time required to complete the measures has been estimated at eight days and the intention is to resume the operation at unit O3 on 29 November.

– Fuel damages may result in reduced power, and since the cold season is just round the corner, it is better to handle this problem now as we still have mild weather in Sweden, says Johan Dasht, production manager at unit O3. When the measures have been completed, we can look forward to stable electricity deliveries from unit O3 until the outage scheduled to start on 29 May 2016.

For further information on any changes, please see the website of the Nordic Power Exchange, nordpoolspot.com. You can also find updated production information on our website Production information.

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E-mail: info@okg.uniper.energy

Phone: +46 491-78 75 50

Page updated Friday, November 20, 2015