Press Releases 2013

Regarding the bent found on part of the spent fuel assembly water rods^*1 at Unit 5 of Kashiwazaki-Kariwa Nuclear Power Station under regular inspection, we have received a directive document^*2 "Bent fuel assembly water rods found at Unit 5 of TEPCO Kashiwazaki-Kariwa Nuclear Power Station (Direction)" from the Nuclear Regulation Authority on November 28, 2012. In accordance with the directive document, appearance inspection of fuel assemblies is being performed.

On March 19, 2013, the inspection of 68 fuel assemblies (subject to inspection) stored in Unit 1 at Kashiwazaki-Kariwa Nuclear Power Station has been completed. As a result, bent was found on part of 6 fuel assemblies and one of them was found to be causing the adjacent fuel rods to touch one another.

Similarly to the case found at Unit 5, the incident found at Unit 1 this time has been judged to apply to Article 19-17, Item 3^*3 of the Rule for the Installation, Operation, etc. of Commercial Nuclear Power Reactors (Rule for Commercial Nuclear Power Reactors) considering that the fuel assembly shape is no longer being maintained.

(Previously announced on March 19, 2013)

Today, we have submitted a report regarding the fuel rods touching one another due to the fuel assembly water rods being bent at Unit 1 of Kashiwazaki-Kariwa Nuclear Power Station to the Nuclear Regulation Authority in accordance with "Article 19-17, Item 3 of the Rule for the Installation, Operation, etc. of Commercial Nuclear Power Reactors (Rule for Commercial Nuclear Power Reactors)".

We will continue inspection in accordance with the directive document received from the Nuclear Regulation Authority to understand the condition and identify the cause of the issue. The inspection results obtained will be reported to the Nuclear Regulation Authority.

Attachment
Reactor Facility Failure Report (Title: Fuel rods touching one another at Unit 1 of Kashiwazaki-Kariwa Nuclear Power Station) (PDF 13.7KB)

*1 Water rod
Hollow tube installed in the center of the fuel assembly in parallel with fuel rods. By passing water through the tube, the output inside the fuel assembly is optimized.

*2 Directive document
"Bent fuel assembly water rods found at Unit 5 of TEPCO Kashiwazaki-Kariwa Nuclear Power Station (Direction)"

*3 Article 19-17, Item 3 of the Rule for the Installation, Operation, etc. of Commercial Nuclear Power Reactors (Rule for Commercial Nuclear Power Reactors)
As stipulated by Article 62-3 of the Act on the Regulation of Nuclear Source Material, Nuclear Fuel Material and Reactors, in the case of an incident which applies to the following, licensees of reactor operation (including former licensees of reactor operation, same as in the following Article and Article 24) must report the incident and countermeasures to the Nuclear Regulation Authority within 10 days from the incident occurrence.
When licensees inspect equipments critical for ensuring safety and the results do not comply with the standards stipulated in Article 9 or Article 9-2 of the Ordinance which specifies the technical standards of commercial nuclear power facilities or when the functions necessary to maintain safety of nuclear facilities are deemed inadequate.

The aforementioned documents are available only in Japanese. We apologize for the inconvenience this may cause.