Researchers at Penn State and Idaho National Laboratory have announced an important breakthrough in sensor technology that promises to improve operating safety and control of reactors in the event of total power failure:
"Thermoacoustics exploits the interaction between heat and sound waves," explains Randall A. Ali, a graduate student studying acoustics at Penn State. "Thermoacoustic sensors can operate without moving parts and don't require external power if a heat source, such as fuel in a nuclear reactor, is available."
In the unlikely (but not unprecedented) event of complete power failure, as occurred when backup generators at Fukushima were flooded with seawater following the earthquake and tsunami of 11 March 2011, these self-powered sensors would allow plant operators to continue monitoring conditions within the reactor in the critical first minutes and hours of an emergency.
A September 22, 2011 memo from Pacific Northwest National Laboratory to Idaho National Laboratory discussing centralized online monitoring and information integration systems addressed the need for such devices.
A little over one year after Chernobyl focused the world's attention on what was then the worst-ever civilian industrial nuclear disaster, the Brazilian city of Goiânia became the scene of another major radiological accident, resulting in several fatalities and widespread contamination. [A definitive 1988 report is available online at IAEA.org. See links and videos at the bottom of this post.]
On September 13, 1987, two men broke into the Instituto Goiano de Radioterapia (IGR), a partially demolished private cancer radiation therapy facility, and carted away a 300kg object in the belief they'd a found a valuable scrap metal item. Roberto dos Santos Alves and Wagner Mota Pereira took the object to Alves' home, about one-half kilometer north of the clinic, and began to dismantle it.
Over the next few days Alves and Pereira cut away at the metal exterior and managed to puncture the casing. Despite the fact both men started to become violently ill with vomiting and diarrhea, they continued their efforts, eventually cracking open the device - inside was a smaller metal canister with a movable "window." When the inner canister's window was pried open, it revealed a mysterious blue glow inside the inner shell. The men scraped away and extracted several small chunks of the glowing blue substance within with a screwdriver to keep as "souvenirs."
On September 18th, Alves sold the object to Devair Alves Ferreira, a nearby scrap dealer. Fascinated by the blue glow, Ferreira invited his family and friends over to see and touch the object. Ferreira's brother Ivo brought some of the powder from the canister home and spread it on his floor; innocently, his 6-year-old daughter Leide played with the powder, rubbed it on her skin, and even ingested a small quantity. Over the next several days, she and others who handled the glowing powder fell ill with vomiting, diarrhea, skin rashes, burns, and blisters.
Now fearing the object was "killing her family," the scrap dealer's wife Gabriela placed it in a plastic bag, boarded a bus, and brought it to the Vigilancia Sanitaria hospital on September 28. One of two doctors who met with Gabriela that day suspected the danger, and placed the bag on a chair in the outer hospital garden, as far away as possible from human contact.
The following morning, a visiting medical physicist with a borrowed radiation detector confirmed the doctor's fears - the hospital now was massively contaminated with radiation. The physicist, identified only as "W.P." in official reports, initially encountered a great deal of resistance alerting authorities to the severity of the emergency. By the end of the following day, W.P. convinced the Secretary for Health of Goias State and the Director of the Department of Nuclear Installations in CNEN to begin a massive search and cleanup operation in the area.
What Alves and Pereira unknowingly brought home from the abandoned clinic was a lead-shielded cancer therapy device containing a lethally radioactive cesium137 chloride (salt) core. All told, 130,000 people were tested for radiation at area hospitals, about 250 were found to be contaminated, and 20 required treatment for radiation sickness. Several houses within the neighborhood had to be demolished, and the rubble buried in a remote waste site. The cleanup effort also was hampered not only by the length of time that passed since the core was exposed and handled, but also by the fact the radioactive powder was water-soluble.
Four deaths are attributed to direct exposure to the cesium core: Leide and Gabriela Ferreira, and two of Devair Ferreira's scrapyard employees succumbed to radiation poisoning about a month after receiving radiation doses of 4.5 to 6.0 Gy (500 to 600 REM). Leide was buried in a lead coffin surrounded by concrete in a Goiânia cemetery, where crowds protested her burial, fearing their relatives' graves would be contaminated. Remarkably, Devair Ferreira survived his massive 7.0 Gy exposure.
The accident - rated 5 on the International Nuclear Event Scale [INES] - spread radioactive contamination throughout the Goiânia districts of Aeroporto, Central, and Ferroviários. To this date an estimated 7 of the device's nominal 50 TBq (terabecquerels) of radioactivity remain unaccounted for.
Image at top from the IAEA 1988 report on the Goiânia Accident. Lower image, by Alexander Sassaki/SIPA Press appears in "Radiation Accident Grips Goiania," by Leslie Roberts, Science, 1987 (see link below).
Pra não dizer...que não falei do Césio-137: from Brazil, focusing on the radiological incident. Very interesting and informative blog, well worth visiting, even if (like me) you need to use Web translation tools for the original Portuguese.
"Radiation Accident Grips Goiania," by Leslie Roberts, Science (New Series), Vol. 238, No. 4830 (Nov. 20, 1987), pp. 1028-1031. Published by: American Association for the Advancement of Science [JSTOR subscription required]
[Note: the URL for this video has been changed] On YouTube, you can view an informative 37-minute TV documentary on the Goiânia accident (in Portuguese) as part of the Linha Direta investigative series, hosted by Domingos Mireilles, containing a detailed re-enactment*: Odesson Alves Ferreira, president of Associação da Vítimas do Césio 137, is interviewed beginning at timestamp 4:18.
IAEA Video: The Legacy of the Goiânia Radioactive Source Accident:
YouTube video: "Enterro de Leide das Neves Ferreira - Apedrejamento e Vandalismo no Cemitério Parque" ("Burial of Leide das Neves Ferreira - Stoning and Vandalism in Cemetery Park")
Any of you Midwestern folks out there have a funny feeling last week? You know, that something might have fallen out of the sky? Nope, no reason. Just askin'. From WIRED News:
WASHINGTON (AP) -- A B-52 bomber was mistakenly armed with six nuclear warheads and flown for more than three hours across several states last week, prompting an Air Force investigation and the firing of one commander, Pentagon officials said Wednesday. The incident was so serious that President Bush and Defense Secretary Robert Gates were quickly informed and Gates has asked for daily briefings on the Air Force probe, said Defense Department press secretary Geoff Morrell. He said, "At no time was the public in danger."
Rep. Ike Skelton, chairman of the House Armed Services Committee, called the mishandling of the weapons "deeply disturbing" and said the committee would press the military for details. Rep. Edward J. Markey, a senior member of the Homeland Security committee, said it was "absolutely inexcusable. Nothing like this has ever been reported before and we have been assured for decades that it was impossible." ...
The plane was carrying Advanced Cruise Missiles from Minot Air Force Base, N.D, to Barksdale Air Force Base, La., on Aug. 30, said the officials, who spoke on condition of anonymity because of a Defense Department policy not to confirm information on nuclear weapons. The missiles, which are being decommissioned, were mounted onto pylons on the bomber's wings and it is unclear why the warheads had not been removed beforehand.
This reminds me of an apocryphal story/urban legend I once heard regarding a nuclear near-catastrophe that supposedly occurred at Plattsburgh Air (NY) Force Base - once a strategic missile site - in the late 1980's, where a technician accidentally armed an ICBM warhead during routine maintenance. Allegedly, the error was discovered and corrected only minutes before the warhead was set to detonate.
I haven't found any independent evidence to corroborate the story, but it still gives me the willies to think what might have happened: at the time was living in Plattsburgh, barely a mile from the facility.
The controversial Dubai Ports deal has spurred heated debate about the widsom of having foreign-owned corporations overseeing management of our national ports of entry. One of our main unsolved port security issues is the problem of uninspected freight containers, which some experts contend may be the route through which nuclear materials or devices could most easily be smuggled into the U.S. for use in a a terrorist attack. From the New York Times's "Big Problem, Dubai Deal or Not":
Only 4 percent or 5 percent of those containers are inspected. There is virtually no standard for how containers are sealed, or for certifying the identities of thousands of drivers who enter and leave the ports to pick them up. If a nuclear weapon is put inside a container — the real fear here — "it will probably happen when some truck driver is paid off to take a long lunch, before he even gets near a terminal," said [retired Coast Guard commander Stephen E.] Flynn, the ports security expert.
That is where concerns about Dubai come in. While the company in question has not been a focus of investigations, Dubai has been a way station for contraband, some of it nuclear. Abdul Qadeer Khan, the Pakistani nuclear engineer, made Dubai his transshipment point for the equipment he sent to Libya and Iran because he could operate there without worrying about investigators.
"I'm not worried about who is running the New York port," a senior inspector for the International Atomic Energy Agency said, insisting he could not be named because the agency's work is considered confidential. "I'm worried about what arrives at the New York port." [read full article, reg. req.]
This week, a private nuclear materials handling firm in the United Kingdom apparently neglected to install a protective "plug" on a cask of radioactive hospital waste being transported by truck across Northern England, causing the cask to emit high levels of radiation during transit. "By pure chance," the radiation beam pointed downwards, away from other vehicles, and no injuries were reported. From the Telegraph UK:
A highly radioactive beam was emitted from a protective flask as it was driven 130 miles, for three hours, across northern England on a lorry, a court heard yesterday....The flask belonging to AEA Technology was being used to transport a piece of decommissioned cancer treatment equipment from Cookridge Hospital, Leeds, to the Sellafield complex, Cumbria on March 11, 2002.
A judge was told how the container was "found to be emitting a narrow beam of radiation, of a very high dose rate, vertically down from that package base". [read full article]
One of the more feared (but rather misunderstood) new terrorist weapons is the "dirty bomb," a conventional explosive surrounded by pieces of radioactive material such as medical waste or spent nuclear fuel instead of ordinary shrapnel. While fatalities from the actual explosion would be relatively limited, the amount of contamination produced by even a small bomb could be considerable - entire city blocks could be rendered off-limits because of hazardous fallout, The Nuclear Regulatory Commission calls dirty bombs "weapons of mass disruption" rather than "weapons of mass destruction" - they create more fear and panic than actual damage, although the financial costs of cleaning up after a dirty bomb could be enormous.
A Canadian company, Vanguard Response Systems, has developed a unique containment system that can be deployed in the event a dirty bomb is discovered before it explodes. It uses a patented "tent" made of several layers of bullet-proof-vest type material, and a special shock-absorbing liquid foam that not only damps the blast, but binds the bomb fragments and radioactive fallout dust produced. Discovery Channel Canada [video stream] shows the containment tents in action using real radioactive material.
This sounds like an intriguing invention - but one with some real-life limitations. I'm afraid the caveat is that bomb squads have to locate the dirty bomb, evacuate the area, and assemble and fill the foam tent before the bomb explodes; very likely if and when one does go off somewhere, it may be without any warning at all. Still, it's some small comfort knowing a device like this exists. Vanguard says the tent and foam system can also be deployed using robotic methods. [via Samizdata]
Shikoku Electric Co.'s Ikata No. 3 reactor is likely to become the third facility in Japan to go "pluthermal" - to use MOX, or mixed-oxide, fuel for power generation. From the Asahi Shimbun:
Shikoku Electric Power Company...Monday informed the Ehime prefectural government of its plans to burn MOX nuclear fuel there by fiscal 2010.
Pluthermal power is controversial because it uses plutonium-uranium mixed oxide fuel, or MOX. Under this method, plutonium extracted from spent nuclear fuel is burned in reactors originally designed for uranium fuel. Pluthermal power is key to the nation's nuclear-fuel recycling program.
Critics warn the pluthermal method carries more health and safety risks to reactors originally designed to burn only uranium fuel. Shikoku Electric Power's plan follows those of Kansai Electric Power Co. and Kyushu Electric Power Co. Kansai Electric Power got the green light from the Fukui prefectural governor in March for its plan to burn MOX at its Takahama nuclear power plant. Kyushu Electric Power in late April notified the Saga prefectural government and the town of Genkai that it plans to burn MOX as early as 2009 at one of its reactors there.
Under Shikoku Electric Power's plan, no more than 16 of the 157 uranium-fuel elements in what are called fuel bundles-groups of fuel elements burned in a reactor-will initially be replaced with MOX at the No. 3 reactor in Ikata. The number of MOX elements will eventually be increased to about one-fourth of the bundle, with the maximum set at 40.
Greenaction-Japan is a organization which opposes the use of "pluthermal" (a Japanese term combining the words "plutonium" and "thermal") power, citing increased safety concerns:
Over the last several years the government and electric utilities have argued that the pluthermal program is a method of recycling precious resources. They claim that it is in Japan's best interest to extract the uranium and plutonium contained in spent nuclear fuel rather than directly disposing of it as some countries do. The argument used is that Japan is an energy poor country which needs to conserve uranium resources and use plutonium for energy security purposes.
Recently promoters of the pluthermal program have begun to argue that the program is also necessary in order to reduce the amount of surplus plutonium accumulated as a result of overseas reprocessing. Since mid- 2001, the Japanese government and electric utilities have put forward yet another argument for the pluthermal program. They claim that without the pluthermal program Japanese nuclear power plants would be unable to continue to produce power...The use of MOX fuel increases the risk and severity of a nuclear accident. When using MOX fuel, the control rods' capacity to function is reduced and power output is less stable and harder to control.
The NRC has a quarterly publication called the MOX: Mixed Oxide Fuels Newsletter, "published quarterly to highlight recent news and events associated with the NRC's licensing of a mixed oxide fuel fabrication facility." The lastest March 2004 issue [PDF file] among other things, talks about the
...October 2003...DOE fil[ing of] an application for license to export up to 140 kilograms of plutonium dioxide to the Cadarache and MELOX MOX fuel fabrication facilities in France. The plutonium would be used to fabricate four MOX fuellead test assemblies, which would be returned to the U.S. for proposed MOX fuel qualification tests in the Catawba Nuclear Power Station. [a two-unit power plant located on Lake Wylie in York County, S.C.]
MOX is (pardon the pun) a highly-charged topic in the United States as well, as the anti-mixed-oxide site Nix-MOX clearly demonstrates with its "Top 10 Reasons to Oppose the Use of MOX":
"MOX IS A BAD IDEA!! MOX infrastructure supplies all the pieces needed for making plutonium a desirable commodity, while it claims to dispose of it. MOX legitimizes the production of plutonium by foreign countries, and creates a market for something that could used in a weapon of mass destruction. Plutonium is dangerous and should be kept out of our economy and out of our commercial reactors."
