Intro

The Radiological Accident in San Salvador IAEA. 3 Men enter a room to clear an obstruction in an industrial facility, it is the 5th of february 1989, within minutes of working in the area they begin to experience headaches and feel ill. The men are working in an industrial irradiation facility just outside san Salvador, and they are experiencing the first symptoms of acute radiation sickness. Within 6 months the 3 men would undergo multiple surgeries which would result in amputations, skin grafts, and for one of the unlucky trio death. The event may sound familiar you might think, but this accident was the ignored warning which led to the soreq radiation event just 1 year later. Today we are looking at the same San Salvador radiation event, I’ll give you my rating later on but first let’s see what rating on my disaster scale you’d give this unfortunate radiological accident.

Background

Irradiation facilities are an important tool for the sterilisation of a multitude of different products including the food and medical industries, and today’s story will be talking about the latter. You see most countries have some sort of radiation facilities be it commercially or governmentally owned, and El Salvador was no different. One such facility was built in 1974 being commissioned in 1975, based near the counties capital city San Salvador. It was commissioned and owned by a Mexican-Salvadorian-Costa Rican consortium. The facility housed a Model JS6300 Gamma Sterilizer, designed built and supplied by atomic energy of Canada ltd, and those of you who have been taking notes during my videos will know they have come up a few times before. As part of the installation process 3 staff were trained by the Canadian company in how to operate the machine. This model of irradiation device makes use of a rack for multiple pencils of which contain radioactive source elements , in this case the gamma ray emitting co60. At the time of installation the total radioactivity was 4.0pbq but this reduces over time necessitating semi regular replacement to ensure reasonable irradiation times. This is held in place by hoist and guy cables. When not being used for irradiation duties the rack is lowered into a water pool for shielding by a pneumatic hoist working the hoist cable. For safety if air is lost in the piston then the rack is returned to the pool via gravity. The whole irradiation machine is housed inside a concrete shielded room, accessible via an area called the maze protected by an interlocked door. The radiation room door can be opened from the inside so that personnel cannot be locked in. An emergency pull cableway was also provided, mounted along the walls of the radiation room and the entrance maze, this actuates a stop switch that lowers the source or stops the startup operation. Materials to be irradiated are usually placed in cardboard or fibreglass boxes, these containers are then themselves placed on a metal tray. pneumatic pistons push the boxes along a set path over 2 levels each time exposing a side of the box to the source. The path the boxes take results in29 irradiation positions and the time in each position was around 2hrs 20 minutes. (Check later) During an irradiation cycle access to the room has to be restricted because of the high risk of exposure to the cobalt 60. The irradiation room had a number of controls to prevent a, access to the room when the source is out of the pool and b, the source being raised when someone is in the room. This was designed into the system by aec ltd, and a vital part of this was the machine key, this was used to open the irradiation room door, operate the control panel and actuate a time delay switch inside the room. And o my one key was used as an extra method to prevent activation of the irradiator when the room was accessed. To enter the room the operator must go to a monitor test panel next to the door. There they would have to initiate a monitor test by pushing the appropriate button. This will take a reading of the radiation levels in the room by using a sensor probe installed near the irradiation machine. Once the button is released the probe must again be able to read background radiation levels before releasing the interlock allowing the door to be opened. If the monitor was already showing a high level of radiation this test cannot be performed. The radiation monitor is also interlocked with the source down microswitch. When the source rack is not fully down (in the storage position), power to the monitor is cut off. This also cuts off power to the key switch that operates the door lock solenoid, stopping anyone from entering the room. After entry and in order to be able to re raise the source rack a time delay key switch must be activated. This system forces The operator to go inside the room and is meant to check if the room is clear of personnel before any attempt to raise the source rack. After operation of the time delay 90 seconds is given. On top of the hardware Enforced safety, proper administrative controls are also meant to be used. This also ties back to that important machine key, on the key ring a radiation monitor is meant to be attached. This is to make sure that upon entry to the room at least one method of dose rate monitoring is provided. This is meant to be calibrated before any entry on a known low radioactive source within the doorframe of the entry door. Now that’s the basics of how the operation was meant to happen, let's return to reality starting in 1975, as the multiple levels of safety controls would break down and be forgotten over the following years. Not long after operation had commenced the facility had its first incident. //////// In 1975 the facility experienced a product jam, product boxes obstructed the movement of the source rack. This caused the rack to deform, allowing the pencils to fall out. But the staff onsite who had been trained by atomic energy of Canada ltd dealt with the incident with no major issues, in response the supplier investigated the issue with the machine and repaired it accordingly. The facility would change hands later on in 1975 when it was sold to a consortium in the United States of America, during the change of ownership the originally trained staff would leave. This resulted in new staff being trained verbally, and not from the original equipment supplier. The facility, like many other establishments in the country at the time, would fall victim to the El Salvador civil war. Beginning on the 15th october 1979 the conflict would run for over 12 years, and as such the facility fell into disrepair as economic hardships gripped the company. Because it was feared the facility may become a target in the civil war, nothing on-site was written down and even the location of plant was not made public knowledge. The owners were fearful of allowing officials from the government onsite and any new employees were told as little as possible including the dangers of the material used by the machinery. The source needed to be replenished by the beginning of the 1980s this was due to the natural decay of the co 60, but costs meant it was left as was. Eventually, in 1981, the owner of the plant reached an agreement with the supplier for the replenishment of the source. A representative travelled to San Salvador, only to turn back at the airport due to the escalating civil war. Another side effect of the civil war was a lack of safety inspections from the supplier, which along with training updates was a vital part of the service that atomic energy of Canada ltd. All of this led to a gradual misunderstanding of the equipment's safety features, as staff trained new staff verbally, resulting in variations way beyond what the original supplier would have given. Another component was that government radiological administration was also lacking...... understandable due to the political issues at the time, but this would result in regulatory legislation being non-existent. The situation wouldn't get much better throughout the 1980s with the facility making do and mending the machinery, including modifications that the manufacturer would never have approved. The lack of maintenance, resulted in the vital monitor probe failing, in order to keep on using the irradiator, it was removed, but you might wonder how the operators would gain access to the irradiation room. Well a neat little trick was discovered, access could be gained to the room by depressing the monitor test switch and repeatedly cycling the buttons on the panel of the radiation monitor. This method became the 'usual' procedure gaining access to the irradiation room, even when the rack was in the deadly up position. Regardless of the now non working interlock,The access door had become badly fitting due to lack of maintenance, which resulted in it being openeable by force or by using the blade of a knife to slip the catch. That leads us to february 1989 and a series of events that would lead to an exposed source not being discovered for 6 days!

Disaster

/////////////// It is saturday the 4th of february, and one of the operators starts this night shift, as was the norm for the facility, he had to deal with a number of power failures and problems with the pistons, but after some wrangling he managed to restart the operation each time. At about 02:00 on Sunday 5 February, during a much needed coffee break, a fault occurred which caused the source rack to be lowered automatically from the irradiation position, needless to say this would be a problem. Lowering the source caused an alarm to sound that indicated that the rack was neither up nor down. The operator returning from his break heard the alarm and promptly went to the control panel to try and perform the reset procedure, but this failed. The next step in the operators repertoire was to leave the building, go outside and climb on to the roof to try and force the source hoist down. This was done by detaching the normal regulated pressurized air supply and applying an overpressured supply. This was to force the source into the fully raised position, hoping that this would free the source rack and permit its descent to the storage position. This non-manufacturer recommended procedure also didn't work, the alarm continued, in order to trick the system, the operator pulled on the cable until it left the hoist mechanism, after this he fed it back down, which activated the micro switch telling the system that the source was down. The operator returned to the control panel, He found that the (red) general failure light and the source up light were on. He went back to the roof and managed to manipulate the microswitch so that upon returning to the control panel the (green) source down light was now on. To gain access to the room the operator now performed another non standard procedure, ever since the monitor probe had been removed a few years before, access to the radiation room was achieved by rapidly cycling the buttons on the radiation monitor panel while turning the key in the door switch. This simulated background radiation readings thus allowing the radiation room to be entered even though the source rack was in the up position. The operator knew the rack was up but it seems like he was not aware of the dangers this posed, as his next move was to cut power to the irradiation machine and enter the room. //////////// The operator entered the room, he did not check the radiation level, once he reached the machine and guided by torchlight only, he started removing product boxes, gradually working his way closer to the up source rack. Near the source rack, he found five boxes jammed into the space for four, he removed two of the boxes, one of which was wedged against the lower of the two source modules in the source rack. This took several minutes, leading to an extended exposure time, unable to fully clear the machine he left the room, restored power and sought out assistance from some of his colleagues.. The operator returned with 2 assisting members of staff, the trio now sought out to reenter the room at around 0300. The 2 staff members ropped into assisting the operator had no training in radiation and the irradiation machine. The operator assured his helpers that the machine was safe if the power was switched off, before entry this was again shut off. The three men entered the radiation room and started to remove product boxes from the third row on the upper level next to the source so that the rack could be freed from above. In order to free the source rack it needed to be lifted, the rack which was around 60 kg needing all 3 for the effort. Standing on the upper level product tray, one of the men pulled the hoist cable, the other two lifted the source rack, after being freed the rack was then lowered into the pool. The men were surprised at the Cherenkov glow that greeted them, the operator seeing this as something to be worried about hurried the men to leave the room, clearly by now he had realized there was indeed some kind of hazard. Not long later the operator started to feel dizziness and nausea, classic initial symptoms of acute radiation sickness. The trio went outside the building to sit down and the operator continued to feel increasingly ill. At about 03:30 he began to vomit blood and two of the men went via taxi to seek medical help. The men made it to the emergency unit of the Primero de Mayo Hospital, upon arrival the other worker began to feel ill at around the same time the 3rd worker who by now had returned to his original working post also felt ill and went to Primero de Mayo Hospital. The company was not made aware of the accident, and instead had put the absent workers down to a sick note exclaiming they had food poisoning. At around 0600 a new worker booked on for duty, he was confronted by the mess of the night shift. He straightened the boxes and started up the facility. When the first operator did not return for his next shift this Worker remained and operated the facility for another shift. But this day 1 exposure event wouldn't be the last of this ordeal but we will have to come back to that in a bit.

Medical

All three of the original exposed men were vomiting. The men were misdiagnosed with food poisoning, given three-day sick leave certificates and were discharged at about 06:00 the same morning they had attended at hospital. The first operator would return to hospital on Tuesday 7 February with nausea and vomiting and also burns to his legs and feet. After he explained to the doctors of the events of the sunday he was diagnosed with "radiation burns" from "acute exposure to cobalt". His symptoms were treated but his condition continued to worsen, the decision was made to transport the patient to another hospital for more specialized treatment. He arrived at the Angeles del Pedregal Hospital in Mexico City on Day 24 post exposure, Tuesday 28 February. He had lost 20% of his body weight, but would make gradual improvements over the next 100 or so days, but amputation of his left leg looked likely as well as a high probability of him developing leukemia. By Day 173 (Thursday 27 July) his condition was considered to have improved enough for him to be returned to the Medico-Surgical Hospital in San Salvador, his condition would however deteriorate. On day 197 after multiple surgeries, damage to his lungs, and a progressively worsening condition he passed away on sunday 20th august. The other 2 exposed workers would fair a bit better due to them only being in the irradiation room once. The second patient who went to the hospital with the operator returned to work 4 days post exposure but was sent home due to his poor health. He again returned to work on day 9 post exposure(Monday 13 February) but was unable to lift an heavy objects, with discomfort in his feet, he returned to hospital where we was then admitted for radiation exposure. Like the operator he too was sent to Mexico City for treatment where he would have his left leg amputated due to necrosis, he returned to san Salvador on day 173, where he would then have his right leg amputated from there his condition improved. The third victim was the least exposed of the 3, he too was transferred to Mexico City but spent less time there, receiving treatment for ARS. Upon returning to san Salvador he would remain off work sick until day 199 post exposure Tuesday 22 August. The operator's mean body was 8.1gy for reference 5gy as a whole body dose can be lethal and he had more than that with his torso receiving an estimated 10. The other 2 men received 3.7 Gy 2.9 Gy respectively.

Disaster Strikes again

Back to the aftermath of the exposure after the first operator never returned to work on Monday evening. Well the company kind of just carried on as normal, what the operators didn't know was that the source rack had been bent, and it was only a matter of time until another incident. Which would come on the wednesday after the initial incident, where the rack became jammed again, but this time was released by the overpressure trick. —— Thursday 9th, day 5 after initial exposure, some of the source pencils escaped the rack and fell into the pool and irradiation room floor. This was discovered on friday day 6, after quality assurance discovered the products had been irradiated less than normal. 4 Workers would enter the room after checking the dose rate on a bepper style detector, outside the door, which was essentially a pointless endeavor as the dose rate outside the room would have been 30 times lower than inside. Upon entering they were exposed to one of the pencils that had escaped the rack, but their exposure was low ranging from 0.22 to 0.09 gy, but this could have been far worse if more pencils had escaped. This now left a massive headache for the owners, how to make the irradiation equipment safe and secure, this forced management to request the suppliers assistance. Two experts from the supplier arrived at the plant on Day 9 (Monday 13 February). They succeeded in determining, by means of a remote television camera and an ion chamber device sent into the radiation room attached to a product carrier, that there was an active source pencil on the upper level. They drilled a hole in the roof of the irradiation room, and On Day 11 (Wednesday 15 February), using a remotely controlled tool, succeeded in picking up the pencil successfully lowering it into the pool. At 19:30 the experts confirmed that the radiation in the radiation room was at the normal background level. Due to the poor state of the facility the supplier disabled the machine, a full count of the source pencils was photographically undertaken and confirmed all were in the pool, in November 1989. The incident was caused by a jam of the fiberglass product boxes, by 1989 many of these containers had become cracked resulting in a higher chance of getting caught within the machine. The boxes were forced against a thin steel bar in the frame in which the source rack is raised and lowered. The deformation of this bar was enough to cause the source rack to become stuck in a raised position. The main issue with the incident was down to the actions of the staff on the day, if the product jam had happened just after the facility had opened it is likely the issue would have been dealt with safely. But 2 decades of neglect and poor training resulted in the dangerous actions of the staff at the facility. Operation of the facility safely was greatly hindered by the political and financial situation in the country as the supplier did not send out staff to inspect the plant due to safety concerns. The plant was refitted with a new irradiator in the early 90’s and subsequently had its safety procedures and safety systems overhauled. This video is a Plainly Difficult production. All videos on the channel are creative commons Attribution-ShareAlike. Plainly difficult videos are produced by me John, in a sunny Southeastern corner of london, uk. Help the channel grow by liking commenting and subscribing! Check out my twitter for all sorts of photos and odd and sods, as well as hints on future videos! I've got patreon and youtube membership as well so if you fancy check them out! All that's left to say is thank you for watching!.