http://aipadvances.aip.org/resource/...xt&bypassSSO=1
Full text at link.
It is unacceptable to me that these researchers had a difficult time getting funding to assess such a threatening situation.
http://www.eurekalert.org/pub_releas...-gtt080713.php
Imaging Fukushima Daiichi reactors with muons
Haruo Miyadera1,a,
Konstantin N. Borozdin1,
Steve J. Greene1,
Zarija Lukić2,
Koji Masuda3,
Edward C. Milner1,
Christopher L. Morris1,
and John O. Perry1,3
1 Los Alamos National Laboratory, Los Alamos, NM 87545, USA
2 Computational Cosmology Center, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
3 University of New Mexico, Albuquerque, NM 87131, USA
(Received 11 February 2013; accepted 17 May 2013; published online 24 May 2013)
The 9.0-magnitude earthquake followed by the vast tsunami on March 11, 2011, caused a nuclear crisis at Fukushima Daiichi.1 Damage of the reactor cores has attracted worldwide attention to the issue of the fundamental safety of atomic energy.2 A cold shutdown was announced by the Japanese government in December, 2011, and a new phase of cleanup and decommissioning was started. However, it is hard to plan the dismantling of the reactors without any realistic estimate of the extent of the damage to the cores, and knowledge of the location of the melted fuel.3,4 In the case of Three Mile Island, it took more than 3 years before a camera could be put into the reactor, and about 10 years before the actual damage to the reactor could be assessed.5 Since access to the reactor buildings is very limited due to high radiation fields, imaging the reactor cores from outside the buildings will be a valuable step, and can reduce the time required to dismantle the reactors significantly, resulting in cost savings and lower total worker radiation dose.
One technique for imaging the cores without access is muon imaging, which utilizes naturally occurring cosmic-ray muons to image large-scale objects. Cosmic-ray muons which have a sea-level flux of 104 m−2 min−16 are the results of hadronic showers high in the atmosphere. Since 1950s, imaging objects by measuring transmitted muons with a muon telescope has been applied to study mine overburden,7 an Egyptian pyramid,8 a temple gate,9 volcanoes,10,11,12,13 a blast furnace14 and caverns.15 By measuring the attenuation of the muon flux, two-dimensional density maps are obtained...
Haruo Miyadera1,a,
Konstantin N. Borozdin1,
Steve J. Greene1,
Zarija Lukić2,
Koji Masuda3,
Edward C. Milner1,
Christopher L. Morris1,
and John O. Perry1,3
1 Los Alamos National Laboratory, Los Alamos, NM 87545, USA
2 Computational Cosmology Center, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
3 University of New Mexico, Albuquerque, NM 87131, USA
(Received 11 February 2013; accepted 17 May 2013; published online 24 May 2013)
The 9.0-magnitude earthquake followed by the vast tsunami on March 11, 2011, caused a nuclear crisis at Fukushima Daiichi.1 Damage of the reactor cores has attracted worldwide attention to the issue of the fundamental safety of atomic energy.2 A cold shutdown was announced by the Japanese government in December, 2011, and a new phase of cleanup and decommissioning was started. However, it is hard to plan the dismantling of the reactors without any realistic estimate of the extent of the damage to the cores, and knowledge of the location of the melted fuel.3,4 In the case of Three Mile Island, it took more than 3 years before a camera could be put into the reactor, and about 10 years before the actual damage to the reactor could be assessed.5 Since access to the reactor buildings is very limited due to high radiation fields, imaging the reactor cores from outside the buildings will be a valuable step, and can reduce the time required to dismantle the reactors significantly, resulting in cost savings and lower total worker radiation dose.
One technique for imaging the cores without access is muon imaging, which utilizes naturally occurring cosmic-ray muons to image large-scale objects. Cosmic-ray muons which have a sea-level flux of 104 m−2 min−16 are the results of hadronic showers high in the atmosphere. Since 1950s, imaging objects by measuring transmitted muons with a muon telescope has been applied to study mine overburden,7 an Egyptian pyramid,8 a temple gate,9 volcanoes,10,11,12,13 a blast furnace14 and caverns.15 By measuring the attenuation of the muon flux, two-dimensional density maps are obtained...
It is unacceptable to me that these researchers had a difficult time getting funding to assess such a threatening situation.
http://www.eurekalert.org/pub_releas...-gtt080713.php
Contact: Jason Socrates Bardi
jbardi@aip.org
240-535-4954
American Institute of Physics
Getting to the core of Fukushima
Study in AIP Advances describes how muon imaging may allow experts to assess damage inside Fukushima Daiichi reactors
WASHINGTON D.C. August 7, 2013 -- Critical to the recovery efforts following the devastating effects of the 2011 tsunami on Japan's Fukushima reactor is the ability to assess damage within the reactor's core. A study in the journal AIP Advances by a team of scientists from Los Alamos National Laboratory (LANL) shows that muon imaging may offer the best hope of assessing damage to the reactor cores and locating the melted fuel.
[snip]
Why is Imaging Fukushima So Challenging?
Assessing the core damage at Fukushima is a very difficult challenge, said Miyadera. In the case of Three Mile Island, cameras were eventually installed in the reactor pressure vessel to assess the damage. However, in the case of Fukushima Daiichi, access inside the reactor pressure vessel has been very limited due to high radiation. To address this, the team plans to install detectors in front of the reactor building and on the 2nd floor of the turbine building so that their muon scattering technique can assess the damage without direct access to the reactor building.
The LANL team has faced numerous challenges, from operating detectors in the high radiation environment at Fukushima Daiichi to the difficulties in finding funding for a project at an American laboratory to address a problem in Japan. The next step for the crew is a demonstration of their technique using a research reactor in Kawasaki, Japan where they will verify the spatial resolution of their technique and track the effects of obstructions such as concrete walls and steel construction materials on the muon scattering...
jbardi@aip.org
240-535-4954
American Institute of Physics
Getting to the core of Fukushima
Study in AIP Advances describes how muon imaging may allow experts to assess damage inside Fukushima Daiichi reactors
WASHINGTON D.C. August 7, 2013 -- Critical to the recovery efforts following the devastating effects of the 2011 tsunami on Japan's Fukushima reactor is the ability to assess damage within the reactor's core. A study in the journal AIP Advances by a team of scientists from Los Alamos National Laboratory (LANL) shows that muon imaging may offer the best hope of assessing damage to the reactor cores and locating the melted fuel.
[snip]
Why is Imaging Fukushima So Challenging?
Assessing the core damage at Fukushima is a very difficult challenge, said Miyadera. In the case of Three Mile Island, cameras were eventually installed in the reactor pressure vessel to assess the damage. However, in the case of Fukushima Daiichi, access inside the reactor pressure vessel has been very limited due to high radiation. To address this, the team plans to install detectors in front of the reactor building and on the 2nd floor of the turbine building so that their muon scattering technique can assess the damage without direct access to the reactor building.
The LANL team has faced numerous challenges, from operating detectors in the high radiation environment at Fukushima Daiichi to the difficulties in finding funding for a project at an American laboratory to address a problem in Japan. The next step for the crew is a demonstration of their technique using a research reactor in Kawasaki, Japan where they will verify the spatial resolution of their technique and track the effects of obstructions such as concrete walls and steel construction materials on the muon scattering...