Three more Japanese utilities, Chubu Electric Power, Japan Atomic Power (JAPC), and Tohoku Electric Power, have been implicated alongside Tokyo Electric Power (Tepco) by Japanese authorities investigating the cover-up of inspection findings in nuclear power plants..
Regulators had been investigating Tepco to determine whether the company had concealed from the Ministry of Energy, Trade and Industry (METI) information from inspection findings made by contractor GE.
On 25 September, fresh cases came to light suggesting that the results of inspections for other BWR owners, carried out by GE, Hitachi and Toshiba, were also falsified to conceal the results. In at least some of these new cases, inspecting firms found cracks in piping and other equipment which are part of the coolant recirculation systems. The crack findings were concealed from regulators by utility personnel. In some cases, utilities repaired piping and related equipment without having reported the findings that necessitated the repairs.
Chubu Electric confirmed that incomplete reports of inspection results had been given to regulators for Hamaoka 1 and 3. The reports failed to mention eight cracks found in core equipment inspected at Hamoaka 3. Chubu said three of the cracks had been repaired. It was also announced that Tohoku Electric had failed to report to regulators cracks that had appeared in recirculation piping at Onagawa 1 back in 1988. On 23 September, investigators revealed that Tohoku has discovered 12 cracks, the largest of which was 14cm long, in the core shroud.
Additional cases of covered up crack findings were also reported by Tepco. According to data Tepco provided to METI, these cases involve flaws found in recirculation pumps and piping connecting the pumps to the primary circuit at Fukushima I-1 to 1-5, at Fukushima II-3, and at Kashiwazaki-Kariwa 1 and 2. Unlike previously disclosed cases of concealed inspection results, the inspections at these reactors were carried out by Hitachi and Toshiba, rather than by GE.
On 24 September, JAPC acknowledged that shroud cracks had been covered up at Tsuruga 1, following inspections carried out by GE in 1994, 1996 and 1998. Hitachi has acknowledged that, in one case, while under contract for BWR inspection work for Tepco in 1992, it found cracks in neutron-measuring equipment at a BWR at Fukushoma. Tepco officials then asked Hitachi personnel to delete the crack finds from their reports. According to a Hitachi spokesman, a senior official in Hitachi’s nuclear plant design division agreed to Tepco’s request because Tepco was a Hitachi client.
•Plans to build six new reactors totalling 9000 MWe at three sites have now been frozen indefinitely. This will halt over half the new nuclear capacity that Japan had intended to have in place soon after 2010, including its first two advanced pressurised water reactors. Tepco has postponed plans to build advanced boiling water reactors at Fukushima I-7 and I-8, and the first two units in Aomori Prefecture, Higashidori 1 and 2. The governor of Fukui Prefecture has withdrawn his approval for construction by JAPC of Japan’s first APWRs at Tsuruga 3 and 4 because of the prefecture’s “loss of trust” in nuclear energy. But industry commentators are saying that this is a political reaction.