At a commercial irradiation facility near Soreq, Israel, the cobalt-60 source rack sticks in the exposed position. Misinterpreting contradictory warning signals, the operator bypasses safety interlocks to enter the irradiation chamber and free the mechanism. He receives an estimated whole-body dose of 10-20 Grays and dies 36 days later.
Errors are made in the maintenance and calibration of a linear accelerator used for clinical radiotherapy in Zaragoza, Spain. Together with violations of proper procedures, these mistakes result in overexposure of 27 patients being treated for cancer between 10 and 20 December. The first signs of radiation injury are seen on 26 December; a total of 18 patients eventually die, and the others suffer major disabilities. This accelerator is related to the Therac-25 involved in several accidents in the United States and Canada.
During a test firing, a missile mis-fires on a newly constructed Typhoon class nuclear-powered ballistic missile submarine. Consequently, all Typhoon-class subs are modified to carry an improved missile.
An experimental chemical cell being used to investigate the phenomenon known as cold fusion explodes at a laboratory in Menlo Park, California, killing Andrew Riley, a British electrochemist.
Cold fusion was so named because at the time it seemed possible that nuclear fusion reactions might be occurring at room temperature in the cells. Because of this, there was a considerable stir over the Menlo Park explosion. Three other cells that Riley and his colleagues had used were buried as a precaution. Subsequent investigation found that it was a purely chemical explosion, with no nuclear processes involved.
While research on cold fusion continues, no trace of nuclear radiation has ever been demonstrated, and no useful energy output has been achieved.
The Los Angeles class nuclear-powered attack submarine Baton Rouge (SSN-689) collides with the Russian Barracuda, a Sierra class nuclear-powered attack submarine. Although able to return to base under her own power, the Barracuda is damaged so severely that she is never restored to service.
Berthed at its home port of Devonport, the HMS Turbulent suffers a fire. A short circuit occurs during maintenance on an electrical switchboard. The resulting blaze burns for five hours in the compartment adjoining the reactor room. Twenty-three sailors are sent to hospital because of smoke inhalation. The incident might have been much worse had the Mechanical Engineering Articifer (MEA) of the Watch not been able to shut down the ship's reactor. Lacking a respirator mask, he might have been unable to do this. But Petty Officer Christian Checkley removes his mask and hands it to the MEA — an act for which Checkley receives the Queen's Commendation for bravery.
An 82-year-old woman is being treated for intestinal cancer at a clinic in Indiana, Pennsylvania. The treatment consists of inserting five wires, each with a "seed" of iridium-192, into her colon. When the wires are being retracted, one breaks, leaving the seed inside the woman. Since the console indicator shows the wires have been safely retracted, the physician and staff ignore a radiation alarm. They do not do a radiation survey with a portable monitor to be sure.
The patient is taken back to her nursing home. The seed falls out on the fourth day and is disposed of in a medical biohazards bag which remains on site for six more days. Workers and visitors are exposed for a total of ten days. When a medical waste disposal truck arrives to carry off the waste, the driver fails to survey the items with a portable radiation meter as per company policy. The source is finally discovered at an incineration facility in Warren, Ohio when radiation alarms indicate contamination.
The staff of the incinerator locate and isolate the bag after an arduous search. Records allow it to be traced back to the nursing home. An NRC Incident Investigation team finds that the woman died five days after her treatment; the Indiana County Coroner's report confirms that she died of acute radiation sickness. The NRC team finds that over 90 people were exposed, with some of the staff receiving significant doses. Announcements in local newspapers bring in some of the visitors who are at risk.
At a 15-million-electron-volt linear accelerator facility in Hanoi, Viet Nam, the facility director enters the irradiation room without the operator's knowledge and unwittingly exposes his hands to the beam. His hands are seriously injured and one has to be amputated.
A radiation facility in the Xinzhou District of Shanxi Province, China loses a 10-Curie cobalt-60 source. The lost source is found by a man named Zhang Youchang, who takes it home. He, his brother and his father die between 3 and 10 December due to radiation exposure. More than 90 other people who might have been exposed to the source are examined. According to a spokesman for the Department of Nuclear Power in China, only five of them have significant exposures and those five "have received appropriate medical treatment."
The Sequoyah Fuels Corporation plant in Gore, Oklahoma is closed after multiple citations by the government over a period of years for violations of nuclear safety and environmental rules. One of two privately owned American manufacturers of armor-piercing shells and reactor fuel rods, the plant had been shut down the week before by the Nuclear Regulatory Commission when an accidental release of toxic gas caused 34 people to seek medical treatment.
The plant had also been shut down the year before when high concentrations of uranium were detected in water in a nearby construction pit. A government investigation revealed that the company had known for years that uranium was leaking into groundwater at levels 35,000 times higher than federal law allows. Carol Couch, the plant's environmental manager, was cited for obstructing the investigation and for knowingly giving federal agents false information.
Unknown to a junk dealer in Mansfield, Ohio, the 2,200 pounds of scrap metal he has bought from the government contain radioactive magnesium from a Minuteman missile. He discovers this and the government spends $80,000 on cleanup of his 27-acre plot. But he later sues the government, claiming his land is still too contaminated to sell. The government contends what little contamination remains is no health threat. On 26 September 2003, district court finds for the government.
The French nuclear submarine Émeraude (S-604) is operating submerged in the Mediterranean. The non-radioactive secondary steam loop in the reactor room develops a serious leak. The vessel's commander and a number of senior members of the crew investigate the leak. Unfortunately, they are not wearing protective clothing. When a steam pipe bursts, they are killed instantly.
Despite the damage and the loss of ten men, the Émeraude is recovered and returns to service. No details on its repair have been made public.
Fire at a nuclear research facility on Long Island, New York results in the contamination of three firefighters, three reactor operators, and one technician. Measurable amounts of radioactive substances escape into the immediate environment.
Authorities confiscate some 300g of weapons-grade plutonium packed in metal tubes inside a lead container from a passenger arriving in Germany on a flight from Russia. This is the largest ever seizure of illegal plutonium.
Three brothers break into the Tammiku repository of nuclear wastes, some 20km from Tallinn, the capital of Estonia. Their intent is to steal and sell some metal. During this caper, someone dislodges a radiation source from its shielding block. It is a small metal cylinder, about 1.5cm in diameter and 3cm long. One of the brothers puts it in the pocket of his jacket. He comes home the next morning to the village of Kiisa and, not feeling well, goes to bed. He is hospitalized on 25 October and dies on 2 November. The diagnosis is kidney failure. Apparently he has told no one about his night-time adventure or the "prize" he obtained.
The next victim is his stepson, who finds the cylinder in the jacket pocket and places in in a drawer containing tools in the kitchen. The 13-year-old boy goes to hospital on 17 November with severe burns on his hands. Only then is radiation recognized as the cause. The police are notified, and a team from the Rescue Board finds the source in the kitchen drawer on 18 November, measuring a dose rate of 20 R/h from it. The source is later identified as cesium-137.
At the age of ten, David Hahn was given a copy of The Golden Book of Chemistry Experiments. This sparked a remarkable episode. By age 12, he had mastered university-level chemistry texts; when he was 14, he made nitroglycerin. His experiments were banished from the bedroom, which he had blown up, to the basement. Soon his activities got him banished from that laboratory too. He set up in the shed behind his mother's house in Commerce Township, Michigan. (His father had remarried.)
In the shed, he graduated from chemistry to atomic physics. He wrote to any agency that had something to do with nuclear power, using a variety of subterfuges to obtain samples and know-how. The NRC was especially helpful. Bulk purchases of smoke detectors and Coleman lanterns gave him tiny pieces of americium and thorium, which he would isolate and weld together with a blowtorch. He collected old clocks and scraped off the paint, concentrating and processing it to purify the radium. The radium went into a lead block with a pinhole, forming a directed source of alpha particles. David aimed these at a stolen strip of beryllium foil, and achieved a primitive neutron gun. The neutron flux let him transmute elements. He began working on making thorium-232 into uranium-233, letting his transmutor run while he was in school or pretending to be a normal teen. His makeshift breeder reactor was well on the way to contaminating the neighborhood; he was able to measure the radiation from five houses away, and it was growing stronger day by day. Fortunately for the neighbors (and for David himself), the authorities stumbled onto his game about this time. The process took almost a year, between bureaucratic procedures and David being uncooperative. But ultimately (on the date given here) they confiscated his materials, dismantled the shed, and shipped everything to a nuclear waste dump. Everything, that is, but the hottest stuff, including the makeshift breeder. His mother had gotten scared and tossed those items in the garbage.
The Federal Bureau of Investigation (FBI) investigates incidents of deliberate contamination at the National Institutes of Health (NIH) and the Massachusetts Institute of Technology (MIT). Resolution TBS, AFAIK.
Armed Russian sailors force Kola nuclear power plant to restore electricity to the Murmansk submarine base, averting possible reactor meltdowns after independent cooling systems in several submarine reactors fail to start. Under a law that took effect in Russia in July, power stations are allowed to cut off service to customers who do not make payments.
Two to three tonnes of sodium leak from the primary coolant loop of the Monju experimental fast breeder reactor at Tsuruga, Japan, starting a fire and filling the building with toxic smoke. The reactor, which began operating in August, was running at 40% capacity when the accident occurred. Yasumasa Togo, head of the Nuclear Safety Commission, describes the accident as "very serious".
Ten days after the accident, the state-owned Power Reactor and Nuclear Fuel Development Corporation, which operates Monju, admits withholding evidence to make the damage seem less extensive than it was. The government promises that Monju will not be restarted until confidence among local residents is restored. A ten-year court battle culminates on 30 May 2005 with approval to restart Monju.
A Houston, Texas radiography company is in bankruptcy. Its three cameras have been impounded in place by the Texas Department of Health, Bureau of Radiation Control (BRC). The Ir-192 in the smallest camera has decayed to minimal activity. The Cobalt-60 cameras, one large (1665 lbs), and one small (631 lbs), contain 35.3 Curie and 8.6 Curie of Co-60 respectively.
On 27 February 1996, all three cameras are stolen. The cameras are stripped of their caution labels and sold to a scrap metal dealer. A complicated web of deceptive transactions ensues, in which the cameras are sold and re-sold, broken up, discovered to be radioactive, and returned to the original dealer. There, on 1 March 1996, the unshielded 35.3-Curie cobalt-60 source falls to the ground and gets kicked under a corner of the main office.
The original dealer again sells the two large cameras, one with the source inside, to different dealers, without mentioning their radioactivity. Six dealers are involved in this incident; no one of them ever notifies the BRC that they possess a radioactive source.
The Texas Natural Resources Conservation Commission, working at the site of the bankrupt company, notifies the BRC that the door from the building where the devices were stored was removed. Upon investigation, BRC determines that the three devices are missing. On 4 March 1996, the BRC issues a news release that is highly publicized by the local media. This helps the BRC to recover the devices. On 5 March 1996, BRC Health Physicists locate the unshielded source. The scrap yard is evacuated and secured; the source is recovered and secured later that evening. Eleven adults and two children are exposed to high levels of radiation at the scrap yard and one adult from dealer B is exposed when he transports and handles the camera and source. Five Houston Police Officers are exposed to low radiation levels when they conduct interviews at dealer A.
A worker at the Combined Cycle Fossil Power Plant in Gilan, Iran is moving insulation materials for the lagging of boilers and pipes in the plant. He notices a shiny pencil-sized piece of metal on the side of the trench and puts it in the loose pocket of his overall on the right side above his chest. The metal object is a 'pigtail' of a radiograph with an iridium-192 source. The man suffers bone marrow depression and an unusually extended local radiation injury. After plastic surgery at the Curie Institute in Paris, the patient's general condition is satisfactory, though his injuries are debilitating.
A cobalt-60 source is replaced at the San Juan de Diós hospital in San José, Costa Rica. When the new source is calibrated, an error is made in calculating the dose rate. The result is that 115 patients receive exposures greater than prescribed. The problem is discovered in late September, and investigation confirms that actual exposures are 50% to 60% greater than calculated. By July 1997, 42 of the patients have died.
Officials shut down the Maine Yankee nuclear power plant in Wiscasset, Maine after discovering that 15 feet of wire are missing from a circuit used to automatically activate a pump in the emergency core cooling system.
Monitor, a magazine of German television, reports that Siemens has made serious mistakes during construction of the Kruemmel nuclear power plant in Germany. Parts of the pressurized-water containment system, according to the magazine, were bent to fit and welded under tension.
The husband of a former Babcock & Wilcox employee returns a floor scrubber, contaminated by more than 1,000 times the radiation levels that the NRC considers safe for public exposure, to the company's plant in Apollo, Pennsylvania. The employee walked off the job three years before, taking the floor scrubber with her.
The scrubber has 1.2 grams of radioactive residue on it. Testing finds approximately 100 square centimeters of fixed alpha contamination and 100 square centimeters of fixed beta contamination. Upon its return, Babcock & Wilcox notifies the NRC of the incident.
NRC spokesman Neil Sheehan says that Babcock and Wilcox has contacted the former employee to determine if and where the scrubber was used during the last three years and to make sure no radioactive material remains in the public domain. Sheehan said there is no information yet of any public contamination. He said the employee's reason for taking the item is unknown, it is too early to determine whether she will face criminal penalties, or whether the NRC would seek criminal or civil penalties against the company.
A shipment of used stainless steel turbine diaphragms is being transported from the Monticello nuclear power plant located near Minneapolis, MN, to Alleron in Koppel, Pennsylvania. The shipment is in two 20-foot-long "c-vans", both loaded on a railroad car. At 1730 EST, the railroad car is in the Conrail yard at Allentown, PA when someone there notices that one of the c-van doors is open to a width of three feet.
This information travels through the railroad's hierarchy. At 19:25 EST, Conrail in Mt. Laurel, New Jersey notifies the Pennsylvania department of environmental protection in Wilkes-Barre, Pennsylvania, of a hazardous materials transportation event involving an open door on a shipping container. Each contains approximately 40,000 pounds of diaphragms with low level surface contamination (class-7 2913-placard material).
The rail car is isolated. Conrail sends a hazardous materials representative to ensure that the load will be adequately secured prior to any further shipment. Pennsylvania's Department of Environmental Protection notifies the state's Emergency Management Agency and also sends a representative to the site. Monticello dispatches a radiation protection supervisor to the rail yard and requests Limerick (located near Philadelphia, Pennsylvania) to send a health physics representative to help in assessing the problem. Monticello is the point of contact with the NRC. It soon informs them that the shipment is intact and not a danger to the public. Conrail's computer records are cleaned up and the rail car is forwarded to its proper destination.
The Nuclear Regulatory Commission extends its list of nuclear power plants in need of urgent safety measures. The five new entries to the list are: Crystal River in Red Level, Florida; LaSalle County in Seneca, Illinois; Maine Yankee in Wiscasset, Maine; Salem in Salem, New Jersey; and Zion in Zion, Illinois.
The North Carolina Division of Radiation Control is notified by the Nuclear Regulatory Commission that a store in Fayetteville, North Carolina sells tritium lighting devices. Further investigation by the NC Division of Radiation Control discloses that an army surplus store is selling tritium lighting devices (torches, personnel illuminators, and map readers) to military personnel as instructed wrongfully by another company which has an NRC license.
On 1/05/89, that company distributed 30 devices (40 sources) and on 05/07/91 they distributed another 24 devices (24 sources). The two shipments totaled 64 sources of tritium measuring 136.9 curies. The store had only 22 sources remaining in stock (46.65 curies of tritium) and they have been shipped back to the licensee. The other 42 sources (90.35 curies) were sold without any records being made of the sale. The state has not yet determined what type of action it will take.
Explosion and fire at Tokai-Mura nuclear fuel reprocessing plant in Japan expose 35 workers to moderate doses of radiation. After attempting to cover up the accident, the Japanese Science and Technology Agency officially declares it Japan's worst.
Due to a defective radiation monitor, Royal Dutch Airlines (KLM) accidentally transports a package of radioactive medical equipment emitting radiation levels far higher than those permitted on board a passenger flight.
Three New Jersey teenagers take a "glow-in-the-dark" exit sign containing 20 Curies of tritium from a demolition site. They break open the tubes of tritium while eating sunflower seeds, thereby ingesting some of the gaseous tritium.
Note: The mention here of sunflower seeds puzzles me. I'd expect it for a powder or liquid. But since tritium is a gas, it does not need to be ingested to get into the body. Anyone who opens a container of tritium without protection is likely to breathe some of it. The only question is how long it remains in the body, and it's not clear that tritium ingested stays around longer than tritium inhaled.
A 400-gallon tank holding about 3 gallons of toxic chemicals explodes at the Hanford Works in Richland, Washington. The blast causes the release of 20,000-30,000 gallons of water from a ruptured fire sprinkler main. Fluor Daniel Hanford, Inc., operator of the site for the Department of Energy, is cited for violations of DOE rules and fined $140,625. Violations cited include the contractor's failure to assure that breathing devices operate properly (though they do) and failure to conduct proper radiological surveys of workers involved (the workers are not contaminated) and failure to assure adherence to criticality safety procedures (although the area flooded contained no fissile materials).
Note: One source paints this as a radiological release; but it doesn't seem to be that. Hanford has enough true releases; there's no point in false accusations.
Building 17 at the Novosibirsk Chemical Concentration Plant is devoted to manufacture of highly enriched uranium fuel rods. The accident occurs during a chemical etching process that removes microscopic defects in the uranium surface prior to its cladding by aluminum. Etching involves immersion of the rods into sodium hydroxide, a water wash, and finally nitric acid. The process leaches tiny quantities of uranium from the rods, some in the form of oxide, which precipitates in the alkali vessel, and some in solution in the nitric acid. Once a batch of rods is etched, the three solutions (and most of any precipitate present) are collected in a common vessel. From there, the mixture is pumped to tanks for eventual recovery of the uranium.
In 1996, a 5.5kg deposit of uranium dioxide was found on inspection of the collection vessel. Analysis showed this to be over ten years in formation, since it contained 36%-enriched uranium, and the transition from that grade to 90% enriched occurred in 1986. Despite this discovery, no other part of the apparatus is checked for uranium accumulations. In addition, the geometry of the vessels was not approved for use with the higher enrichment level.
Building 17 is promptly evacuated when the criticality alarm sounds at 1055 hours on Thursday, 15 May 1997. Twenty-five minutes later, emergency response personnel measure dose rates of 10 R/h at half a meter from the holding tanks on the ground floor. They dissolve 20kg of boric acid in water and introduce it into the tanks to absorb neutrons. Despite this, five more excursions occur, at varying intervals, into the early morning hours of 16 May. Finally, at 1400 on 16 May, a concentrated solution of lithium chloride is added after a sixth excursion when radiation levels are lower. This permanently suppresses the reaction. Equipment is undamaged. Exposures for the closest 20 people do not exceed 0.4 rem.
Analysis of the solutions indicates a total mass of 7.8kg, too low by a factor of 13 for criticality in these particular vessels. However, it is soon found that the tanks contain a slurry which, when filtered, loses 95% of the total uranium as precipitate. The bottoms of both tanks contain a crust of precipitate, and both are deformed for unknown reasons. The deformation reduces the criticality safety margin. The precipitate is dissolved and reclaimed, both tanks are replaced, and a regular inspection for precipitate accumulation and tank deformation is begun.
At the Sarov (Arzamas-16) facility, an experimental apparatus is being hand-constructed on a vertical-movement platform. This platform is part of a system known as FKBN-2M in which the lower portion can be raised or lowered and the upper portion moved horizontally. Like all such current setups, this one is equpped with a gravity-driven fast scram system to drop the lower platform out of the reactivity zone if neutron flux exceeds a preset value. The construction is being done by an experimenter working alone and without having completed the proper paperwork — both violations of safety procedures.
Working from notes and logbooks, he is attempting to duplicate an experiment first performed in 1972. This consists of several concentric hemispherical shells of material containing 90%-enriched uranium, with an outer reflector of copper. However, he makes two mistakes. The first is recording a diameter of 265mm for the reflector; the correct value is 205mm. This apparently leads him to use too many fuel shells. His second mistake comes when he is mounting the other hemisphere of the reflector onto the upper platform. It slips from his hands and falls onto the lower portion of the assembly. Instantly there is the blue flash, and the criticality alarm sounds. The lower platform scrams, but this is no help since the critical configuration remains intact upon it.
The experimenter leaves the room, closes the shielded door behind him, and reports to the engineer and health physicist who are on duty in the control room. He then remains to describe his notes to the facility chief, who arrives shortly thereafter. He is flown to Moscow for treatment the same day, but this is unavailing since he has absorbed 4,500 rad from neutrons and 350 rad from gamma rays. He dies on 20 June.
Analysis shows the initial spike of radiation is followed by another excursion lasting 3 to 5 minutes, and by a series of highly damped oscillations at roughly 40-minute intervals. The reaction then reaches equilibrium. Conditions preclude its termination for seven days. Finally, on 24 June, a vacuum gripper is used to remove most of the assembly from the stand, leaving only the lower copper hemishell in place. Later the apparatus is further disassembled, all by remote control. Total energy yield of the accident is equivalent to that from 10 19 fissions. Minimal equipment damage occurs, no one else is exposed, and the experiment room is not contaminated. Safety upgrades to the FKBN-2M system are made.
During recent years, many unsecured radioactive sources have been found in the Republic of Georgia. The local authorities first request international assistance in October 1997, when a group of border guards undergoing training at a centre in Lilo, near Tbilisi, become ill and show signs of radiation-induced skin disease. Eleven servicemen are transferred to specialized hospitals in France and Germany. The cause of the exposures is found to be several cesium-137 and cobalt-60 sources of various intensities, abandoned in a military barracks that used to be under the control of the former Soviet Union. In July 1998 three more abandoned sources with intensities of 50 GBq, 3.3 GBq and 0.17 GBq are found in Matkhoji, an agricultural village about 300 km west of Tbilisi. At the same time, another former Soviet military base close to Kuthaisi is found to contain an area contaminated with radium-226. Another military base in the city of Poti, close to the Black Sea, is also found to contain two further radioactive sources buried in a sand floor. In October 1998 two other powerful sources were discovered in Khaishi, western Georgia. The sources are part of eight thermo-electric generators placed in the region. These generators used to hold an activity of anything between 740 and 5550 TBq. Since then, four of the generators have been located and are now in safe storage. One is recovered from the bed of the Inguri river which flows through this region in western Georgia. Two other discoveries: on 21 June 1999, a cobalt-60 source of around 37 GBq is found buried below a road close to the botanical gardens in Tbilisi; on 5 July 1999, two cesium-137 sources are found in the town of Rustavi, close to Tbilisi.
During routine tests aboard a moored Russian nuclear-powered submarine, a cooling system pipe breaks, releasing ammonia and nitrogen gas into the compartment. Five crew members are injured; one, a Captain of the Third Rank, succumbs. The vessel is reportedly the Oscar-II class guided missile submarine Tomsk.
During a classified exercise 125 miles off Long Island, New York, the USS Kentucky (SSBN-737) collides with the fast attack submarine USS San Juan (SSN-751). At the moment of collision the Kentucky is at the surface and the San Juan is running submerged. According to US Navy official data, the submarines suffer minor damage and return to Groton naval base for extensive checks. There are no casualties. Lt. John Wallach, a Navy spokesman, describes the collision as "extremely uncommon".
The FBI is called in to investigate the circumstances surrounding the discovery of a large stash of radioactive materials in the Bronx, New York. Among the radioisotopes found are cesium-137, strontium-90, carbon-14, and radium.
A Troxler Gauge is taken from a locked storage shed at the McMinn's Asphalt Company in Lancaster, Pennsylvania. The 70-pound tool is used to measure the density of asphalt and contains an 8-millicurie cesium-137 source. It was the only thing taken from the shed. Neil Sheehan, a spokesman for the Nuclear Regulatory Commission, says a health threat would exist if the stainless steel capsule containing the source were broken open.
Old teletherapy sources kept in a firm's warehouse in Ankara, Turkey are put in lead containers for shipment to the supplier. They remain there for about five years because of commercial disputes. In December 1998, the firm ships the containers to another warehouse in Istanbul. But instead of placing the shipment in the deposit yard, workers place it in a facility next door, where it remains for about nine months. When those premises are sold, the new owners sell the unwanted items, including the containers with the sources inside. The buyer takes the containers to an open yard and with another person dismantles them. Ten persons receive radiation doses high enough to cause acute radiation syndrome. One of the sources remains missing.
A welder at the construction site of a hydroelectric power station in Yanango, Peru, 300 kilometers east of Lima, inadvertently picks up an iridium industrial source intended for gammagraphy operations but left uncontrolled. He puts it in the back pocket of his trousers. He is initially hospitalized at the Lima Anti-Cancer Centre, suffering from severe radiation burns, and later transferred to the Serious Burns Treatment Centre of the Percy Military Hospital at Clamart (Hauts-de-Seine) in France. Doctors there expect he will benefit from a treatment technique used for serious burns which proved effective on Georgian security guards who were victims of a serious radiation accident in 1997.
A worker at a Burlington, MA high-tech firm mails off a 200-pound package containing enough radioactive iridium to kill anyone who rips it open. The package is supposed to arrive by Federal Express at a Mexican construction firm the next morning. It never gets there. For days, frantic regulators, Federal Express staffers, and executives of AEA Technology QSA, the sender, search the region — including a mile-by-mile surveillance of the route from Burlington to Boston's Logan Airport — for signs of any radiation leakage. The Nuclear Regulatory Commission goes on special alert, just as though there had been an accident at a nuclear power plant. The package is found, intact, in a hangar at a small airport outside London, England. Federal Express says it's just a routine mix-up. Robert Hallisey, director of the radiation control program of the Massachusetts Department of Public Health, says that an estimated half-million shipments of radioactive material pass through Logan each year, many of them substances used in nuclear medicine. The NRC says that nationwide, misplacement of nuclear materials similar to the AEA incident this month occurs about once a year. NRC records indicate that a Dupont package of radioactive medicine was temporarily lost in February, and later recovered.
A technician at Livermore National Laboratory in California fails to fully assess bagged materials to be discarded. Bulk uranium remains in the waste that is placed into a plastic garbage bag. Soon the uranium undergoes spontaneous combustion and ignites other contents of the bag. The fire causes minor contamination of the immediate area.
President Clinton announces that contract workers at U.S. nuclear weapons facilities, exposed to toxic and radioactive substances during the previous 50 years, can seek federal compensation for related illnesses.
The Washington Post reports that thousands of workers were unwittingly exposed to plutonium and other highly radioactive metals over a 23-year period beginning in the mid-1950s at the Paducah Gaseous Diffusion Plant in Kentucky. Reportedly, some workers handling plutonium were told it was uranium, and breathed in fine particles of the more dangerous metal without knowing it.
In addition, a chance discovery of "black ooze" in a field a quarter-mile from the plant led to the finding that the field was contaminated with radioisotopes including uranium and technicium. The level of contamination was nine times higher than that which, inside the plant, would have made the affected area off limits. The finding corroborates charges made in a lawsuit filed in June by workers at the plant that wastes had routinely been dumped illegally outside the premises. Cleanup is expected to be done by the DOE.
Preparing nuclear fuel for a research reactor, three Japanese workers mix uranium oxide and nitric acid in a steel tank instead of the special, favorable-geometry mixing apparatus. This procedural shortcut has been in use for seven or eight years, and is part of an operating manual drafted by the company. The manual has not been approved by Japan's Nuclear Safety Institute. These workers are experienced, but have not been trained in this particular operation. They wear neither dosimeters nor protective gear.
The tank has a 100-liter capacity, and when 40 liters of the 18.8%-enriched uranium compound have been poured into it, the mixture goes critical. (The mixing apparatus will not hold enough solution to permit a fission chain reaction.) The three workers receive extreme doses; two die within months. Another 63 people are also severely exposed as they aid the first victims and seek to shut down the fission reaction. It goes on, intermittently, for 20 hours and finally is stopped when the tank's cooling water jacket is drained; that water was acting as a neutron moderator, facilitating the reaction. Total estimated yield is 2.5x1018 fissions.
The site of Japan's worst nuclear accident to date is the uranium reprocessing facility in Tokai-mura, Ibaraki Prefecture, 100km northeast of Tokyo. Outside the plant, no evacuation takes place for 5 hours. At that time, the mayor of Tokai-mura orders all townspeople living within 350 meters of the plant boundary to move to more remote locations. None of these people receives a dose greater than 25 mSv. There is measurable contamination outside the plant, but the maximum reading is 0.01mSv/hr and it decays quickly to insignificance.
The accident points up serious deficiencies in both the plant's management and Japan's nuclear-industry oversight. Specifically, the JCO Company is totally unprepared for such an accident. It has no equipment to monitor neutron radiation sleeting through the plant and the nearby wooden houses of townspeople. Nor is there any emergency plan for such accidents as this. The gamma-ray alarms are not tied into a plant-wide criticality alarm system, and in fact JCO's license states that a criticality accident is not a credible event. The government revokes this license.