http://www.nytimes.com/2011/04/06/world/asia/06nuclear.html Original article in NYT.
New York Times
U.S. Sees Array of New Threats at Japan’s Nuclear Plant
By JAMES GLANZ and WILLIAM J. BROAD
Published: April 5, 2011
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. …The document, which was obtained by The New York Times, provides a more detailed technical assessment than Japanese officials have provided of the conundrum facing the Japanese as they struggle to prevent more fuel from melting at the Fukushima Daiichi plant. But it appears to rely largely on data shared with American experts by the Japanese. …..The document also suggests that fragments or particles of nuclear fuel from spent fuel pools above the reactors were blown “up to one mile from the units,” and that pieces of highly radioactive material fell between two units and had to be “bulldozed over,” presumably to protect workers at the site. The ejection of nuclear material, which may have occurred during one of the earlier hydrogen explosions, may indicate more extensive damage to the extremely radioactive pools than previously disclosed. ….Even so, the engineers who prepared the document do not believe that a resumption of criticality is an immediate likelihood, Neil Wilmshurst, vice president of the nuclear sector at the Electric Power Research Institute, said when contacted about the document. “I have seen no data to suggest that there is criticality ongoing,” said Mr. Wilmshurst, who was involved in the assessment. …The N.R.C. report suggests that the fuel pool of the No. 4 reactor suffered a hydrogen explosion early in the Japanese crisis and could have shed much radioactive material into the environment, what it calls “a major source term release.”
Experts worry about the fuel pools because explosions have torn away their roofs and exposed their radioactive contents. By contrast, reactors have strong containment vessels that stand a better chance of bottling up radiation from a meltdown of the fuel in the reactor core. ” End Quote
As at 31 March 2011 there is the view among many many ordinary people that the reactors at Fukkushima Diiachi continue to release radio nuclide emissions into the air as well as the sea.
Officially, TEPCO, IAEA and governments insist that emissions into the air have ceased and dismiss the possibility that the continued release of radionuclides into the sea have an environmental impact. The official view is that the reactors at Fukushima Diiachi are not a present and continuing hazard in any form. That nothing is noteworthy, that no facts about the current state of the reactors deserves the continuing attention of the people of the world.
The salient points of the New York Times report are:
1. There is a confidential report issued by the NRC regarding the state of the Fukushima Diiachi reactors. ”
2. They saw an array of “fresh threats” at the plant.
3. These previously undeclared threats could “persist indefinitely”.
4. Attempts to achieve “stability”, these threats could result in the “increase” in severity of the threat level.
5. This confidential information “leaked” to the NYT newspaper contained more detailed information than Japanese offiicals had released to the world. BUT:
6. The information was derived from that SHARED by Japan with the USA NRC.
7. Fragments or particles of fuel rods were “blown up to one mile from the (reactor) units.”
8. The folly of multiple units located together was shown by highly radioactive material having to be “bulldozed over, presumably to protect workers at the site.”
9. The ejection of “nuclear material” which “may” have occurred during the earlier “hydrogen” explosions
10. The ejection of this material – fragmented fuel rods – “may indicate more extensive damage to the extremely radioactive (fuel) pools than previously disclosed.”
11.”engineers who prepared the document do not believe that a resumption of criticality is an immediate likelihood.” The one answer which is the most likely to the issue raised by David Chanin is thus discounted by: “Neil Wilmshurst, vice president of the nuclear sector at the Electric Power Research Institute”.
And it is this denial which seems debunked by the science Journal “Nature” as quoted last post.
12. “The N.R.C. report suggests that the fuel pool of the No. 4 reactor suffered a hydrogen explosion early in the Japanese crisis and could have shed much radioactive material into the environment, what it calls “a major source term release.” The events of 14 – 15 March 2011 at the spent fuel pool number 4 almost certainly involved an explosion and a fire, and a major release of fresh used fuel rod contents. This seems responsible for a large escalation of the crisis and marked the phase of a major fudging of events. A review of news footage for those two days of Australian TV media shows this fudging. REwatching those TV news programs now listening for mention of a fuel pool event results in no clear description of events.
13. “Experts worry about the fuel pools because explosions have torn away their roofs and exposed their radioactive contents.” Yet this official fear has been played down and nuclear industry and its spokespeople have been extreme in denial that this ever was or could be a factor affecting Japan.
In truth, the history of nuclear reactor approval since the late 1960s has revolved around this very vulnerability of spent fuel pools. The technical vulnerability of spent fuel pools and the inability of industry to solve the on site storage of spent fuel are key vulnerabilities of every reactor on earth. And the fears have been actualized not by ideology but by the facts of the matter. The containment buildings are gone, blown away as a result of the use zircalloy as fuel rod cladding, and its ability to liberate Hydrogen from water at high temperatures. If this is the best design for fuel rods, the use of material in fuel rods which causes explosions sufficient to destroy containment buildings, then the people have been lied to for decades by nuclear industry.
Ongoing criticality might be due to fuel pool disturbance by hydrogen explosion enabled by the use of zircalloy as cladding. It may also be caused by fuel melt within the reactors. The greatest store of nuclear material being in the fuel pools.
The storage of many tons of contaminated water is one example of a growing threat brought about by attempts to reach stability at the reactors.
The NRC reports also raises questions about the stability and integrity of the reactor vessels themselves:
Source: New York Times, NRC leaked document.
One may speculate on the source of the leak. It probably was not any of the NRC commissioners who sought the expulsion of the former NRC Chairperson Gregory B. Jaczko. For these commissioners are famous for acting for the interests of the nuclear industry.