Stewart & Radsafers,
I'm curious about this skyshine from industrial radiography sources, which you mentioned in the anecdote below.
How would such common occurrences compare - dose-wise - to the dose received by people in the vicinity of the 1999 criticality accident in Tokaimura - "Japan's worst nuclear accident ", "the worst nuclear accident since Chernobyl, angering radiation victims", which "exposed more than 600 people to radiation."
Would these be roughly the same order of magnitude ?
Thanks.
Jaro
^^^^^^^^^^^^^^^^^^^^^
-----Original Message-----
From: Stewart Farber [mailto:farbersa@optonline.net]
Sent: Wednesday February 26, 2003 5:44 PM
To: Radsafe
Subject: Re: Nova - Dirty Bombs - London Scenario question/critque
An afterthought on the scenario of someone driving around a city like London with
a 2,000 Ci [74,000 GBq] Cs-137 source in their auto. I recall doing a background
radiation survey [short duration High Pressure Ionization Chamber readings of
total gamma background], the better part of a mile from the Bath Iron Works in
Bath, Maine just as Maine Yankee was going operational.
During the readings at a substation a location for routine TLD monitoring,
background levels jumped about 50% for a few minutes and then returned to normal,
followed by a series of jumps of similar magnitude and then return to background.
I called the RSO at the Bath Iron Works to ask if they had been doing any
industrial radiography at certain specific times I specified.
After a long pause, he asked how I could know this since I was offsite at a
distance he could not imagine my being able to get a reading.
The point is, I was able in 1974 to be aware of an industrial radiography source
being removed from its shield [despite local shielding used by the users of the
source taking the shot] at a distance of almost a mile, due to skyshine from the source.
Isn't it rather trivial to set up even rather crude real time radiation sensors
around any major city that could track the presence and movement [of a gamma
source at least] into or near a city quite easily such that the source could be
intercepted before it gets to the heart of a city? A helicopter with a radiation
sensor could pinpoint the location of any vehicle carrying a substantial
unshielded source [like that hyped in the NOVA program] in a matter of minutes
and it could be intercepted by authorities before it might be exploded.
Stewart Farber, MS Public Health
email: farbersa@optonline.net
[203] 367-0791
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Plant operators get suspended jail terms for Japan's worst nuclear accident
Agence France Presse, 03 Mar 2003
by Miwa Suzuki
TOKYO, March 3 (AFP) - A Japanese court on Monday gave suspended prison terms to six employees of a uranium processing plant charged in the worst nuclear accident since Chernobyl, angering radiation victims.
Workers at the Tokaimura plant in 1999 poured too much uranium into a precipitation tank and watched helplessly as a blue flash signalled the start of Japan's gravest nuclear accident.
It exposed more than 600 people to radiation and forced around 320,000 to shelter indoors for more than a day. Two of the workers who triggered the disaster later died from their injuries in hospital.
Six employees of JCO Co. Ltd, which operated the plant, were arrested in October 2000 on charges of professional negligence and violating nuclear safety laws.
"I had hoped for unsuspended terms," Shoichi Oizumi, 74, who heads a group of radiation victims, told reporters, while admitting he had braced for light sentences given the limited legal penalties imposed for such charges.
A second radiation victim seemed insulted that those responsible for exposing so many to radiation got away with such modest punishment.
"I have to keep worrying about my health for the rest of my life," the middle-aged man told the Japan Broadcasting Corp.
A defence lawyer triumphantly pumped his fists when the suspended sentences were announced, Jiji Press news agency said.
The heaviest sentence was imposed on Kenzo Koshijima, 56, the head of the facility in Tokaimura, 120 kilometres (75 miles) northeast of Tokyo.
Koshijima was fined 500,000 yen (4,240 USD) and given a three-year suspended jail sentence. Should he break the law within the next five years he will be made to serve his jail term.
Mito District Court presiding judge Hideyuki Suzuki noted the accident "greatly shook public trust in the nuclear processing business and atomic safety."
But he caused a stir when he told the court the sentence would be suspended for five years, Jiji said.
Koshijima issued a statement after the ruling expressing his "deep gratitude for the leniency."
The others, including an injured survivor of the accident, were also given suspended prison terms of up to three years.
JCO, accused of supervisory lapses that permitted dangerous practices to be conducted for more than a decade, was fined one million yen.
Breaking nuclear safety laws carries a maximum one year jail term, or a fine of up to one million yen. The maximum punishment for professional negligence resulting in death is five years imprisonment, or a fine of up to 500,000 yen.
The defendants had pleaded guilty but called for leniency, arguing the government was also to blame for failing to supervise the plant.
The ruling rejected the state's responsibility, however, saying the defendants were trying to pass off the blame to the government.
JCO has agreed to pay more than 14 billion yen in compensation for the economic damage suffered by local companies.
A couple who ran an auto parts factory about 120 metres (400 feet) from the plant, sued JCO and its parent Sumitomo Metal Mining last September, demanding 57 million yen in compensation for damage to their health.
Public trust in Japan's nuclear operations was dashed by the accident and was further eroded by news last year that power utility companies were found to have falsified safety records at nuclear plants for years.