According to an internal inspection of the fourth Hanbit containment building of the Korea Hydro & Nuclear Power (KHNP), 14 voids with a maximum depth of 30 cm were additionally confirmed.
Accordingly, KHNP will additionally check the third Hanbit containment building, which was built in the same time as the fourth Hanbit with the same construction methods.
Hanbit Nuclear Power Sites have 6 units in operation. Currently, units 1 to 4 are under preventive maintenance, and units 5 and 6 are operating normally.
“In the 4thHanbit containment building, a 20cm depth hole was found that exceeded the initial expected depth of 8cm. In order to secure the safety of the public, we will thoroughly inspect the 9 ~ 15 stages of the inner iron plates (CLP) inside the 4th Habit containment building,” stated the Hanbit Nuclear Power Site.
Two concrete voids were discovered in November last year, and six other concrete voids were discovered in may this year that had a depth of 8cm around the 4thHanbit containment building (the thick iron plate to be installed before the containment concrete pouring) and the stiffener (the L-shaped section to prevent distortions),
Since June 26th, The Hanbit Nuclear Power site joint investigation team investigated reinforcements installed in the 1st and 8th stage of the internal plate (CLP) of the 4thHanbit containment building.
Based on the results of the thickness measurements and impact sound tests, the joint investigation team cut internal iron plates for the 69 suspicious areas that had voids.
Including the larger pores (unfilled areas), the company found a total of 14 concrete voids. The depth of the void was about 8cm mostly due to the shape of the stiffener installed. However, three additional voids with depth of 20cm or more (21cm, 23cm and 30cm) were found in the fourth Hanbit containment building.
The KHNP also started additional inspection and maintenance work on the third Hanbit maintenance building.
As many unexpected voids were found in the fourth Hanbit containment building, detailed inspection of the 4thHanbit containment building as well as the 3rdHanbit containment building was inevitable.
In response, civic groups urged thorough reinvestigation into the construction process of the nuclear power sites. The Energy Justice Action pointed out that the problem with the concrete voids in the 3rd and 4thHanbit containment buildings and the shutdowns caused by poor maintenance of the main water supply pump in the 4th Uljin containment building are clearly showing the shameful nature of the nuclear site industries
The civic group first noticed the problem of the construction of the Yeonggwang Nuclear Power site in Korea in 2016 when it began to investigate the issue of the iron plate (CLP) for the 2ndYeonggwang containment building, and also found other issues with the iron plates in other sites such as the 1st and 2ndYeonggwang site, 1stUljin site, and the 3rd Gori containment building.
