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.
GE'S INVOLVEMENT GE has said that it did not know until late in the day that one of its own US employees had told Japanese regulators that GE's client, Tepco, had been concealing results of GE-performed BWR core internals inspections. During the investigation of the affair four implicated GE employees were indefinitely suspended.
GE is continuing its investigation to provide information to METI as well as the basis for disciplinary action and preventative measures. According to some sources, when Japan's regulator NISA first followed up the allegations from the GE whistleblower, they could not be confirmed because Tepco had destroyed inspection records and, apparently of its own accord, repaired the equipment cited. NISA maintained contact with the whistleblower, however, and he tipped off NISA to another case where inspection results had not been reported.
According to one source in Japan, METI did not contact GE about any allegations of concealed inspection findings until November 2001. According to GE, for months after METI said its whistleblower made his allegations, GE management was not aware of any systematic irregularities at Tepco reactors involving GE's findings. GE said that as soon as the matter had been brought to its attention, it immediately began an intensive inquiry, and promptly contacted METI and Tepco to guarantee full co-operation.
GE has provided METI with copies of inspection documents in cases where Tepco's copies of the records were destroyed one year after the inspections were carried out. According to some sources, GE documented 20 cases of irregularities. According to Tepco, based on information provided by GE, 29 cases of irregularities were discovered and details passed on to METI.
TEPCO'S REPORT TO METI Tepco has submitted a report to METI in which it compared GE's documents with its own documentation. Out of the 29 cases, Tepco believes that 16 were 'inappropriate'. However, there were no safety issues with any of the cases.
Tepco admitted in the report that there had been 'systematic and inappropriate management of nuclear power inspections and repair work' over a long period. Tepco's report said that employees in charge of maintenance work would have had to follow such precedents, even if they believed something to be wrong. Tepco concluded that the responsibility lay with the nuclear power stations as a whole, and with the nuclear power sections of the head office, and finally, the top management of these sections.
The report also addressed the motives for this misconduct. For employees in charge of inspection and maintenance work, the most important concern was to complete periodic inspections and to bring their own plants back on line as scheduled. Top management in the nuclear departments had similar concerns and priorities. These concerns and priorities resulted in the view that maintenance sections did not have to report problems to the regulator and local governments in the vicinity of the stations as long as there were no safety implications. Nonetheless METI is considering criminal prosecutions against Tepco personnel because 'actions taken were probably illegal under Japanese law'.
Tepco is taking measures to attempt to prevent a recurrence of the present situation by: l Improving transparency l conducting more stringent internal audits and reforming the corporate culture l thoroughly complying with a suitable model of corporate ethics.
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