instructions from headquarters, given the difficulty of the situation and delays in
executing procedures.
Yes, but at that moment, it was the first time for me as well that I found myself confronted
with such a situation, and, to be very honest, I didn’t even understand it myself. We didn’t
yet know the details of the situation on the ground. And in that, we were in the same
position as the people at headquarters. Of course, on the ground, they couldn’t see the
indicators in the control room any more – they were in the dark, all the main instruments
were off, but we were under the impression that if they were set to vent, this could happen.
Of course, there was no electrical power supply, or air supply, but bizarrely, we were
completely convinced that in order to vent all we had to do was open a valve, that if we
could open this valve, it would work. We only understood afterwards. The AOV had no air.
Naturally, the, MOV did not work either. We wondered if we could do it manually. But
there was too much radioactivity for us to go in. And that’s where we finally realized how
difficult it was. But we could not get the message across to the head office or Tokyo, get
them to see how difficult this venting was [12].
Although the order to vent would be repeated by the government, it would be
repeatedly delayed because the levels of radioactivity made it impossible to access
the valves. The Director then realised the differences between the people at head
office and the situation on the ground, and that the order could not be executed. He
therefore adapted the procedure, taking into account the state of the system at the
time. Later in the hearing, he spoke of the distance that was created between
headquarters and plant staff. The same problem also existed at the plant itself—
between the crisis unit, the control centre and shift teams who had to manually carry
out the venting and who would be exposed to the high levels of radioactivity. It was
this distance that led the Director and his team to take important decisions without
the approval or authorization of headquarters. These actions included the decision
to cool reactors with seawater.
The hearing indicates that preparations were carried out much further upstream
than the strict chronology of events would suggest. Knowledge of the system status
necessitated the use of a cooling source that was available in large quantities. The
only option was the on-site seawater. Independent of any discussions with headquarters, the plant’s staff prepared to execute the order.
Here, it’s not really a case of ‘continue’. To be really precise, we began preparations for this
seawater injection well before 2:54 p.m. This means that the order to prepare the injection
was given well before then. But it was at that time that the preparations were completed and
the injection became possible. This is why I gave this order, which was more like an order
to implement that an order to prepare, if I remember correctly. Except, this is when the
explosion occurred. We could not move to implementation and we ended up back at the
beginning. What is clear is that the order to look at how to inject seawater was given at an
earlier stage. [12, p. 169].
While TEPCO’s management were aware of the intentions of the plant’s
Director and the crisis unit, they did not take part in any discussions or decisions
about pumping procedures or water transport. Only on-the-ground personnel knew
what resources were available and how to adapt them to the situation. Furthermore,
after an initial attempt, the order was given to suspend the manoeuvre; the Director
decided to continue, but did not reveal his decision to headquarters.
Consequences of Severe Nuclear Accidents …
51
executing procedures.
Yes, but at that moment, it was the first time for me as well that I found myself confronted
with such a situation, and, to be very honest, I didn’t even understand it myself. We didn’t
yet know the details of the situation on the ground. And in that, we were in the same
position as the people at headquarters. Of course, on the ground, they couldn’t see the
indicators in the control room any more – they were in the dark, all the main instruments
were off, but we were under the impression that if they were set to vent, this could happen.
Of course, there was no electrical power supply, or air supply, but bizarrely, we were
completely convinced that in order to vent all we had to do was open a valve, that if we
could open this valve, it would work. We only understood afterwards. The AOV had no air.
Naturally, the, MOV did not work either. We wondered if we could do it manually. But
there was too much radioactivity for us to go in. And that’s where we finally realized how
difficult it was. But we could not get the message across to the head office or Tokyo, get
them to see how difficult this venting was [12].
Although the order to vent would be repeated by the government, it would be
repeatedly delayed because the levels of radioactivity made it impossible to access
the valves. The Director then realised the differences between the people at head
office and the situation on the ground, and that the order could not be executed. He
therefore adapted the procedure, taking into account the state of the system at the
time. Later in the hearing, he spoke of the distance that was created between
headquarters and plant staff. The same problem also existed at the plant itself—
between the crisis unit, the control centre and shift teams who had to manually carry
out the venting and who would be exposed to the high levels of radioactivity. It was
this distance that led the Director and his team to take important decisions without
the approval or authorization of headquarters. These actions included the decision
to cool reactors with seawater.
The hearing indicates that preparations were carried out much further upstream
than the strict chronology of events would suggest. Knowledge of the system status
necessitated the use of a cooling source that was available in large quantities. The
only option was the on-site seawater. Independent of any discussions with headquarters, the plant’s staff prepared to execute the order.
Here, it’s not really a case of ‘continue’. To be really precise, we began preparations for this
seawater injection well before 2:54 p.m. This means that the order to prepare the injection
was given well before then. But it was at that time that the preparations were completed and
the injection became possible. This is why I gave this order, which was more like an order
to implement that an order to prepare, if I remember correctly. Except, this is when the
explosion occurred. We could not move to implementation and we ended up back at the
beginning. What is clear is that the order to look at how to inject seawater was given at an
earlier stage. [12, p. 169].
While TEPCO’s management were aware of the intentions of the plant’s
Director and the crisis unit, they did not take part in any discussions or decisions
about pumping procedures or water transport. Only on-the-ground personnel knew
what resources were available and how to adapt them to the situation. Furthermore,
after an initial attempt, the order was given to suspend the manoeuvre; the Director
decided to continue, but did not reveal his decision to headquarters.
Consequences of Severe Nuclear Accidents …
51