Masao Yoshida, general manager of the Fukushima No. 1 nuclear plant, believed the worst-case scenario — the “China syndrome” — might be near and he braced for death during the late-night hours of March 14, three days after the crisis started.
Pressure was rising at an alarming rate inside reactor No. 2, keeping plant workers from injecting critical coolant water into the reactor’s core to prevent the fuel rods inside from melting down as power had failed following the March 11 earthquake and tsunami.
To prevent panic among the plant employees, Yoshida secretly ordered a few of his staff members to prepare a bus for everyone to evacuate except for a small number of key operators.
That was one of the darkest moments of the meltdown crisis at the Fukushima No. 1 nuclear plant, as revealed in an interim report by a government investigation panel published Monday.
Yoshida was thinking that the dreaded China syndrome — in which nuclear fuel melts down and burns through the containment vessel, spreading massive amounts of radioactive materials into the environment — might happen soon in reactor 2.
If that were to occur, workers would have to flee and the same catastrophe would also hit reactors 1 and 3, Yoshida judged.
The report reveals a critical lack of knowledge and communication among plant workers and government officials at the prime minister’s office, which the panel says exacerbated the meltdown crisis at the plant.
The report, however, also leaves unanswered some key questions about critical moments of the accident, including when Yoshida was preparing the bus to evacuate the workers.
During previous interviews with the media, then Prime Minister Naoto Kan and Chief Cabinet Secretary Yukio Edano claimed Tokyo Electric Power Co. CEO Masataka Shimizu told the government that Tepco wanted to withdraw all of the plant workers early March 15, hours after Yoshida ordered his staff to prepare the evacuation bus.
According to Kan, when he met Shimizu early March 15, Shimizu was still “not clear about if (all the workers) would be withdrawn or not,” and Kan felt Tepco could eventually abandon the Fukushima plant. Kan thus decided to take full control of the emergency operations at the plant by setting up a joint headquarters of the government and Tepco at the utility’s head office in Tokyo.
But according to the panel’s report, Shimizu “clearly denied” to Kan that he was thinking of withdrawing all plant workers and abandoning the plant when he met Kan. The panel didn’t interview Kan and other top government officials during its investigation.
According to the panel, before the meeting with Kan, Shimizu had told Nobuaki Terasaka, head of the Nuclear and Industrial Safety Agency, that Tepco “may withdraw” its staff from the plant if the situation deteriorated further.
Shimizu, however, claimed Tepco was thinking of maintaining some staff to keep monitoring the plant, although he didn’t explicitly say so to Terasaki because he thought “that was a matter-of-course” assumption that was shared by Terasaki.
But after Shimizu’s message was delivered to Terasaka, all of the key Cabinet members, including Kan and Edano, believed Shimizu had proposed that Tepco abandon the plant amid the crisis, according to the report.
At that time, three of the six reactors were facing meltdowns and the coolant temperature was rising in the large spent fuel pool of unit No. 4. Abandoning the entire Fukushima plant would have led to a catastrophe of huge proportions, severely contaminating much of eastern Japan — even possibly Tokyo and its surrounding area — with highly radioactive materials.
“If the plant had been abandoned, all the reactors would have melted down and (the severity of the accident) would far exceed that of the Chernobyl accident. There were no ‘letters of withdrawal’ in mind” as an option, Kan said in an interview with the Asahi Shimbun on Sept. 6.
During a meeting at the prime minister’s office early March 15, everyone there, including Kan, concluded they could “never accept withdrawal of all the workers,” which prompted Kan to later arrange the meeting with Shimizu, according to the report.
Since then, Kan and other key ministers have claimed Tepco told them they were withdrawing all of the workers and abandoning the plant, which Tepco officials have denied.
The panel will interview Kan and other key government officials, which will be reflected in the final report that the panel plans to submit to the government by around summer.
By 1 a.m. March 15, the pressure in reactor No. 2 fell slightly, which allowed Tepco to inject coolant water into the core. Yoshida didn’t order the evacuation of any plant workers until another crisis took place when an explosion was heard at the reactor No. 2 building around 6 a.m. that day, according to the report.
Hearing the blast, Yoshida had about 650 workers evacuate at 7 p.m. from the Fukushima No. 1 plant to the nearby No. 2 plant.
But 50 workers who were desperately needed to monitor and fix the damaged reactors at No. 1 stayed under Yoshida’s order. Eventually they came to be known and praised as the “Fukushima 50” around the world.