“United States government engineers sent to help with the crisis in Japan are warning that the troubled nuclear plant there is facing a wide array of fresh threats that could persist indefinitely, and that in some cases are expected to increase as a result of the very measures being taken to keep the plant stable, according to a confidential assessment prepared by the Nuclear Regulatory Commission.” – NYT 4/6/2011
Simply put, the method being used to keep the fuel cool in the absence of a cooling systems has been to pour water (initial seawater) onto the fuel. Unfortunately, this method has produced a new host of issues that U.S. and Japanese engineers are only beginning to understand.
Threats to containment:
1) Rupture vulnerability due to rising levels of radioactive cooling water
2) Explosions inside the containment structures due to the release of hydrogen and oxygen from seawater pumped into the reactors
Threats to workers:
1) Radiation burns to workers who step into leaking radioactive water
2) Ongoing exposure to radioactive particles and releases
It is not to suggest that the medicine is worse than the malady, but as engineers continue to suggest new antidotes to counteract the side effects of the current method, it is clear that all the lessons from this crisis have yet to be gleamed.
In response, every other major nuclear power state except the U.S. has suspended their nuclear program. In this continued atmosphere of trial and error, the U.S. Nuclear Regulatory Commission will conduct a review of domestic regulations intended to protect the public and environment from a nuclear accident. And in the meanwhile, the process of relicensing aging nuclear reactors will continue without interruption.
The logic behind this decision makes as much sense to me as using fission to boil water.