Recently posted reports on News.iaea.orgA syndication of the most recent reports on news.iaea.org.uuid:82e70401-b432-4080-bfcc-1c75721c6630;id=16Copyright International Atomic Energy Agency (IAEA)2024-03-19T09:48:09Ze5f9f74c-99e5-400a-b873-6605416d5fbfInternal contamination of a worker in a fuel pellets fabrication workshopThe event occurred in the pelleting workshop, where mixtures of plutonium and uranium oxide powders are compacted into cylindrical pellets. These operations are carried out in glove boxes. While cleaning a glove box containing a compacting press, one of the gloves was punctured, causing atmospheric contamination of the working area. This contamination was detected by the room’s radiation monitors and the area was evacuated in accordance with the procedures in force.
One of the three people present in this room was contaminated. The CEA Marcoule medical service then took charge of this person.
Orano Cycle informed ASN of this event on 12 February, indicating that radio-toxicological analyses had been run to estimate the committed dose for this person.
These analyses, which lasted several months, show that the committed dose could exceed the annual dose limit set at 20 mSv. Therefore, on 24 June 2020, Orano Cycle reported this event as a “significant event” in accordance with ASN’s requirements. The CEA Marcoule medical service and Orano Cycle are continuing their investigations in order to determine the committed dose value, since the estimated committed dose for this event is far higher than expected on the basis of the atmospheric contamination level measured by the workplace monitors when the event occurred.
This event had no consequences on either the installations or the environment. Orano Cycle cleaned the room and assessed the equipment used. The licensee started to work on improving the mechanical strength of the gloves and the configuration of the workstations. ASN will also assess the results of investigations concerning the relationship between the level of contamination measured by the monitors and the estimated committed dose.2024-02-07T15:25:39+01:002024-02-07T15:25:39+01:00Autorité de Sûreté Nucléaire (ASN), Francea23f85fc-026b-4870-8be1-205a0d255350Internal contamination of a worker in a fuel pellets fabrication workshopThe event occurred in the pelleting workshop, where mixtures of plutonium and uranium oxide powders are compacted into cylindrical pellets. These operations are carried out in glove boxes. While cleaning a glove box containing a compacting press, one of the gloves was punctured, causing atmospheric contamination of the working area. This contamination was detected by the room’s radiation monitors and the area was evacuated in accordance with the procedures in force.
One of the three people present in this room was contaminated. The CEA Marcoule medical service then took charge of this person.
Orano Cycle informed ASN of this event on 12 February, indicating that radio-toxicological analyses had been run to estimate the committed dose for this person.
These analyses, which lasted several months, show that the committed dose could exceed the annual dose limit set at 20 mSv. Therefore, on 24 June 2020, Orano Cycle reported this event as a “significant event” in accordance with ASN’s requirements. The CEA Marcoule medical service and Orano Cycle are continuing their investigations in order to determine the committed dose value, since the estimated committed dose for this event is far higher than expected on the basis of the atmospheric contamination level measured by the workplace monitors when the event occurred.
This event had no consequences on either the installations or the environment. Orano Cycle cleaned the room and assessed the equipment used. The licensee started to work on improving the mechanical strength of the gloves and the configuration of the workstations. ASN will also assess the results of investigations concerning the relationship between the level of contamination measured by the monitors and the estimated committed dose.2024-02-07T15:24:24+01:002024-02-07T15:24:24+01:00Autorité de Sûreté Nucléaire (ASN), France807e96d9-70c9-4701-bfc5-f5d634f771b0Worker exposure to X-ray generatorOn May 29, 2021, two workers were inspecting and calibrating the fluorescent X-ray adhesion meter (output 50kV x 40mA) at the Nippon Steel Setouchi Works in Himeji City, Hyogo Prefecture.
There are three main operations for irradiating X-rays with this device.
・ Power supply to this device
・ Increase the voltage and current of the X-ray tube
・ Open the shutter of the irradiation window.
These operations are usually performed on the control panel outside the irradiation room where the device is installed.
Initially, the two workers were working on the control panel outside the irradiation room, but when the calibration sample showed abnormal measures, they entered in the irradiation room with the device on power. There is no legal requirement for this facility to have interlocks, which cut off the power supply when the irradiation room door opens.
As the two workers in the irradiation room confirmed some deposits on the X-ray irradiation window of the device, one of the workers removed them with a hand tool, and the other assisted.
The two workers believed that they had closed the shutter of the irradiation window when entering the irradiation room, but it was revealed that the shutter had not been closed and that the workers were exposed to the X-rays emitted from the device during the operation.
On May 30, 2021, two workers were hospitalized and treated following physical complaints and erythema on their arms and faces, which are non-fatal symptoms. The two workers left the hospital by the end of December 2021.
Base on the results of the biological dosimetry (measurement of the frequency of chromosomal abnormality) conducted by November 2023, the experts evaluated the exposure to 400-500 mGy for one worker and less than 100 mGy for the other worker.2024-02-02T01:18:44+01:002024-02-02T01:18:44+01:00Nuclear Regulatory Authority, Japan3d552858-060e-4d97-a6e8-eed798c58d10Radon Exposure at Boarding SchoolThe incident occurred at a private boarding school where pupils, employees and their children had been exposed to high levels of radon gas in the atmosphere.
The two employees and their two children were exposed to the high radon gas levels as a result of working and living at the school. The five overexposed pupils studied and lived at the school during this time.
An investigation by the regulator (Health and Safety Executive) found that the school knew they had a radon problem as far back as 2007 when they carried out monitoring and installed some remediation to reduce radon levels. However, from 2010 to 2018 the school carried out no subsequent radon monitoring and had no systems in place to ensure radon control measures were adequate. Only following an intervention by the regulator in 2018 did the school find out about their previous radon problem when further radon monitoring and remediation was subsequently carried out to reduce radon levels.
Dose estimations were made based on expected occupancy times for the individuals for that year, these were as follows:
Employee 1 : 15mSv
Employee 2 : 15mSv
Employees child 1 (member of the public): 14mSv
Employees child 2 (member of the public): 14mSv
Pupil 1: (member of the public): 8mSv
Pupil 2: (member of the public): 8mSv
Pupil 3: (member of the public): 8mSv
Pupil 4: (member of the public): 8mSv
Pupil 5: (member of the public): 8mSv
The annual effective dose limit in the UK for employees is 20mSv and for members of the public is 1mSv.2024-01-26T14:34:23+01:002024-01-26T14:34:23+01:00Office for Nuclear Regulation (ONR), United Kingdomcfd216c1-7b9d-4653-9e55-10b13e8da30dDeclaration of Unusual Event (NUP-4.1)On January 4, 2024, the Unit 1 was operating at 100% power. At 09:00 (local time) the steam tunnel cooling unit “1-RRA-FC-009A” was started due to equipment rotation resulting in the loss of energy in the Motor Control Center (MCC) “1-R31-MCC-1BA-AA” with the failure of the electrical protection of the cubicle 5D of the MCC “1-R31-MCC-1BA-A”.
At 09:05, the Auxiliary Reactor Operator reported the presence of smoke in the MCC “1-R31-MCC-1BA-A” preventing the manual opening of the cubicle 5D.
At 09:10, the Auxiliary Turbine Operator reported that the switch 7A that energize the MCC “1-R31-MCC-1BA-A” could not be manually open.
At 09:17, the Auxiliary Reactor Operator reported the presence of fire in the MCC “1-R31-MCC-1BA-A” located in the elevation 18.70 of the Reactor Building. The bus 14BA was de-energized by manually opening the switches 14BAM and 14BA resulting in entry to the procedure 1-OA-0556 "Loss of 4160/480VAC non-critical". The fire brigade was activated according to the procedure PAS-32 "Fire Protection Program".
At 09:32, an Unusual Event was declared due to fire in the protected area not extinguished in 15 minutes (NUP-4.1).
At 09:45, the Chief of the fire brigade reported that the event had been controlled and that maneuvers to recover the area would begin.
At 13:30, the Unusual Event was declared finalized.2024-01-12T23:41:33+01:002024-01-12T23:41:33+01:00Comision Nacional de Seguridad Nuclear y Salvaguardias, Mexicoc3618f61-bb55-4d4e-a268-31d56391a8aaWorker Exceeded Annual Whole Body Dose LimitA radiography trainee received a dose of 0.075 Sv (7.50 rem) to the whole body and 0.258 Sv (25.8 rem) to the extremities due to a disconnected 2.33 TBq (63 Ci) Ir-192 source. This dose was determined through reconstruction of the event and dose calculations. The trainee did not wear his dosimetry badge and he did not turn on his alarming rate meter. He connected the source without supervision and began to take radiography shots of a pipe. After the third shot, he cranked the drive cable without the source back in the camera. He did not perform a survey to make sure the source was back in the camera. He walked up to the pipe and exchanged the film. He moved the end of the guide tube inside the pipe placing his hand approximately four inches from where the source was located. He walked back and cranked the drive cable back to the end of the guide tube and backed away from the cranks during the shot time. He repeated this three more times, and while he was disconnecting the guide tube from the camera to switch to a guide tube with a collimator, he noticed that the indicator on the camera showed that the source was not back in the camera. He checked his personal dosimeter and found it off scale. He reported this to his trainer. The radiation safety officer and an assistant arrived to perform the source retrieval. They inspected the source assembly connector and the drive cable connection, and connected them. They cranked the source back into the camera. The trainee did not have any symptoms of radiation exposure, which was supported by daily pictures of his hands and weekly bloodwork collected for a month. The cause of the incident was failure to properly connect the source assembly to the drive cable followed by a failure to use a survey meter. Another cause was that the trainer did not supervise the trainee. The licensee reported that they have conducted retraining with all radiographers and have suspended the two radiographers in this incident. The licensee has reported that they will increase the frequency of their audits. The dose to the trainee exceeded the U.S. regulatory limit for the annual whole body dose of 0.05 Sv (5 rem). EN56761.2023-12-07T14:35:30+01:002023-12-07T14:35:30+01:00Nuclear Regulatory Commission (NRC), United States of Americac7a174ac-0b8a-463f-bd32-ad3f3a233de2Worker Exceeded Statuary Annual Whole Body Dose LimitsOn 24.09.2023, an employee of a company carried out a weld inspection in a radiation protection bunker using an X-ray device. After the measurement, the employee – who is also the radiation protection officer - went into the bunker to carry out further work. After completing the work inside the bunker, he realized that the X-ray device might still have been in operation during his stay. The immediate evaluation of the dosimeter provided a value of 71.5 mSv for September 2023. The dose measured with the dosimeter was above the annual limit of 20 mSv for occupationally exposed persons. The annual dose in 2023 before the event was 0.0 mSv. An expert inspection of the X-ray equipment determined that the equipment was technically in order. Therefore, it is assumed that it was not a malfunction of the device, but potentially a human error when operating the device. Further investigations are currently being carried out.2023-11-08T15:51:27+01:002023-11-08T15:51:27+01:00Gesellschaft für Anlagen und Reaktorsicherheit (GRS) mbH, Germany14b24234-38ba-45cb-bf78-dbc728f1172bStolen cat-3 source in MexicoA radiography camera (Industrial Nuclear Co.,model IR 100) along with a pickup vehicle was stolen by organized crime in Corregidora Ortiz 1ª Sección S/N, primera-5A, Ciudad del Carmen, Tabasco. México. The IR 100 camera serial number is 7510 and contains a CATEGORY 3
radioactive source of Ir-192.
The device was recovered on October the 25th, 2013 at approximately 15:00 (UTC-6) in Ocozocuautla de Espinosa, Chiapas, Mexico. The device was found intact and in good working order, and the radioactive source safely stored inside it.2023-10-25T22:33:53+02:002023-10-25T22:33:53+02:00Comision Nacional de Seguridad Nuclear y Salvaguardias, Mexico5a43e799-5249-49dd-b649-c5ac897a1dabStolen cat-3 source in MexicoA radiography camera (Industrial Nuclear Co.,model IR 100) along with a pickup vehicle was stolen by organized crime in Corregidora Ortiz 1ª Sección S/N, primera-5A, Ciudad del Carmen, Tabasco. México. The IR 100 camera serial number is 7510 and contains a CATEGORY 3
radioactive source of Ir-192 (15 Ci).2023-10-18T22:20:43+02:002023-10-18T22:20:44+02:00Comision Nacional de Seguridad Nuclear y Salvaguardias, Mexico4bbd7d13-7abb-4a80-82fb-0b788a1b5d75Contamination of an employee and the break room in a nuclear medicine departmentOn 26 July 2022, the SCINTIGARD radiology centre in Nîmes notified ASN of an incident concerning the contamination of a radiographer during the preparation of a scintigraphy examination, and dissemination of the contamination in the staff break room of the centre.
On 21 July 2022, the radiographer in charge of preparing the radiopharmaceutical drug syringes was in the break room when the alarm of the active dosimeter worn under his lead apron was activated. The subsequent verification confirmed contamination of the skin of one of the person's forearms. The radiographer immediately underwent the decontamination procedure prescribed for this type of situation.
The centre's radiation protection advisor then carried out radiation checks in the rooms and on the equipment; they revealed a low level of contamination in the preparation chamber and on the edge of the table in the break room. The chamber and table underwent surface decontamination, but the table edge could not be entirely decontaminated therefore the break room was closed and the still-contaminated area was cordoned off until the radioactive elements had decayed. Given their short half-life, these radioactive elements disappear naturally in a few days.
The event resulted more specifically from noncompliance with several internal procedures, including:
- utilisation of the shielded radiopharmaceutical preparation chamber without prior installation of the gloves that seal the chamber;
- failure to check for contamination on leaving the contamination-risk zone, which delayed detection of the contamination;
- and sub-optimal allocation of the radiographers' tasks during the vacation period.
The initial dosimetric results transmitted seemed to indicate that the dosimetric consequences of this event for the worker would be limited, as the received doses in principle remained below the maximum values set by the regulations. Based on these factors, ASN provisionally rated this event level 1 on the INES scale and published an incident notice on 12 August 2022.
The analysis of the radiotoxicological examinations of the radiographer's urine revealed internal contamination within the statutory limits. However, based on complementary analyses conducted by IRSN, the French Institute of Radiation Protection and Nuclear Safety, the equivalent dose to the skin received by the worker was estimated at more than 4 times the statutory limit of 500 mSv over twelve consecutive months.
Given that the statutory occupational exposure limit for the skin was exceeded in a single event, ASN uprated this event to level 2 on the INES scale (International Nuclear Event Scale, rated from 0 to 7 in increasing order of severity).
The centre sent ASN a significant event report with proposed corrective actions. These actions were analysed then discussed during an on-site ASN inspection on 6 April 2023. They raised no remarks from ASN. The centre was nevertheless informed that it must verify the medium- and long-term effectiveness of the corrective action.2023-08-09T09:13:58+02:002023-08-09T09:13:58+02:00Autorité de Sûreté Nucléaire (ASN), France722cf26b-6f8b-4810-989b-ad0e189f3444Accidental exposure of workersOn March 24th 2023 during the unloading of a transport package with a radioactive source of I-131 (4.07 TBq), contamination was detected on the inside of the package. After taking a swab, contamination was determined at the level of 200 Bq/cm^2. Four workers were contaminated (hands, personal protective clothing). Additionally the fork lift, floor in laboratory, foil on the floor and corridor were contaminated. Estimated effective doses to the four persons involved were between 1,01 mSv to 6,08 mSv. The dose constraint for the workers was established on 15 mSv. The contaminated areas were temporarily closed and successfully decontaminated.2023-08-09T06:27:40+02:002023-08-09T06:27:40+02:00Radiation Emergency Centre, National Atomic Energy Agency, Poland1fb22467-988f-419e-8c58-5fa0386690d4Stress corrosion: presence of a deep crack on the safety injection system of reactor 1 of the Penly NPPOn 6 March 2023, EDF sent ASN an update of its significant safety event notification concerning the presence of stress corrosion cracks on several of its reactors. This update concerns reactor 3 of the Cattenom NPP and the reactors of the Civaux, Chooz B and Penly NPPs.
This update includes in particular the detection of a crack situated near a weld on a line of the safety injection system hot branch (RIS BC) of the Penly NPP reactor 1. The crack extends over 155 mm, i.e. about a quarter of the pipe circumference, with a maximum depth is 23 mm for a pipe wall thickness of 27 mm.
EDF considered that this line was not susceptible to stress corrosion, due in particular to its geometry. However, the weld underwent a double repair during reactor construction, which could have modified its mechanical properties and the internal stresses of the metal in this zone.
The presence of this crack means that the strength of this pipe is no longer demonstrated. The reactor safety case does however take into account the rupture of one of these lines.
In this update, EDF indicates that the inspections have also detected the presence of a thermal fatigue crack on lines considered to be susceptible to stress corrosion of the safety injection system (RIS) of reactor 2 of the Penly NPP and reactor 3 of the Cattenom NPP. The pipes in question were replaced under the programme EDF has initiated on the RIS system lines of the type P'4 reactors.
This event has no consequences on the personnel or the environment. Nevertheless, it affects the safety function associated with reactor cooling. Due to its potential consequences and the increased probability of rupture, ASN has rated this event level 2 on the INES scale for reactor 1 of the Penly NPP and level 1 for the other reactors concerned.
EDF is implementing an inspection programme on the repaired welds of the RIS and RRA systems. More than 150 welds have undergone expert assessments in the laboratory and the inspections are continuing, with an inspection programme covering all the reactors as from 2023.
ASN has asked EDF to revise its strategy to take into account these new findings. It will shortly give a position statement on this revised strategy.2023-05-30T07:54:42+02:002023-05-30T07:54:42+02:00Autorité de Sûreté Nucléaire (ASN), France49ddf93a-54c5-44f7-914a-16392fd2e6eeExternal contamination of a worker leading to exceeding of the annual statutory dose limitOn 3 February 2023, ASN was notified by the Cattenom nuclear power plant licensee of a significant radiation protection event concerning the exceeding of an annual individual dose limit by an employee of an EDF contractor.
On 2 February 2023, this worker was reinstalling thermal insulation on valves of various systems in the building of reactor 3, which was shut down for inspection and repair work linked to the stress corrosion phenomenon. The radioactivity check performed on leaving the controlled zone detected skin contamination on the worker's cheek. The worker received immediate medical attention and the radioactive particle causing the contamination was removed.
For workers likely to be exposed to ionising radiation in the course of their professional activity, the annual statutory dose limits for twelve consecutive months are 20 millisieverts for the whole body and 500 millisieverts for a skin surface area of 1 cm².
EDF evaluated the received dose by retracing the path and activity of the worker within the reactor building. This evaluation gives a dose at the worker's cheek exceeding the regulatory limit set for the equivalent dose to the skin. The whole body dose received by the worker, however, is well below the annual statutory dose limit .2023-04-03T14:23:10+02:002023-04-03T14:23:10+02:00Autorité de Sûreté Nucléaire (ASN), Francec20a7fa0-2d12-4153-956d-2212c486b76fMissing Dangerous Source at Salamanca, Guanajuato, Mexico.On March 22, 2023 at approximately 11:00 a.m. (UTC-6), the theft of four industrial radiography devices with the following characteristics was reported to the CNSNS offices:
1. Brand: AEA Technology, model: DELTA 880, Serial No. D2810, which houses a radioactive source of Ir-192 with serial number 083H with a current activity of 7.61 Ci.
2. Brand: QSA Global Inc, model DELTA 880, Serial No. D5824, which houses a radioactive source of Ir-192 with serial number 370G with a current activity of 0.11 Ci.
3. Brand: Source Production & Equipment Co, Model: SPEC-150, Serial No. 2173, which houses a radioactive source of Ir-192 with serial number C0052 with a current activity of 35.64 Ci.
4. Brand: Industrial Nuclear Co., model IR100, serial No. 4829, which houses a radioactive source of Ir-192 with serial number TT3561 with a current activity of 1.14 Ci.
The theft took place on March 22, 2023 at approximately 3:00 a.m. (UTC-6), when armed persons entered the licensee’s facility located in Pánfilo Nájera 205, Col. Lázaro Cardenas, Salamanca, Guanajuato, Mexico. They extracted the four sources and a van.
On Tuesday March the 28th, 2023 at approximately 17:30 (UTC-6), The devices were found near to Salamanca Guanajuato due to an anonymous call. The devices were verified by the licensee and all radiological risk was discarded. The devices were recovered and returned to the licensee who took them to its facility. Search for the perpetrators is underway.
On Wednesday March the 29th 2023, a group of inspectors of the Regulatory Authority was sent to Salamanca, Guanajuato in order to verify that the devices were safe and the licensee facility had fixed and improved the security systems. At approximately 17:33 (UTC-6), the inspectors had given their approval to the new security measures placed in the facility.
The actions taken were: a) The theft has been reported to the law enforcement agencies; b) The National Regulatory body has notified the National Civil Protection Agency; c) Search for the missing industrial radiography devices is underway; d) A search team of the Regulatory Authority has been dispatched to the site in order to help and advice the responders; e) The Regulatory Authority personnel gave theoretical training to local first responders on radiological issues; f) The Licensee filed a legal complaint with the Prosecutor´s Office; g) The devices have been recovered. Radiological risk has been discarded and, e) The regulatory authority has inspected the improved security measures of the facility and found them satisfactory.2023-03-30T20:21:19+02:002023-03-30T20:21:19+02:00Comision Nacional de Seguridad Nuclear y Salvaguardias, Mexicof23338de-f9a9-425d-ac9a-2ca2d3d01128Missing Dangerous Source at Salamanca, Guanajuato, Mexico.On March 22, 2023 at approximately 11:00 a.m. (UTC-6), the theft of four industrial radiography devices with the following characteristics was reported to the CNSNS offices:
1. Brand: AEA Technology, model: DELTA 880, Serial No. D2810, which houses a radioactive source of Ir-192 with serial number 083H with a current activity of 7.61 Ci.
2. Brand: QSA Global Inc, model DELTA 880, Serial No. D5824, which houses a radioactive source of Ir-192 with serial number 370G with a current activity of 0.11 Ci.
3. Brand: Source Production & Equipment Co, Model: SPEC-150, Serial No. 2173, which houses a radioactive source of Ir-192 with serial number C0052 with a current activity of 35.64 Ci.
4. Brand: Industrial Nuclear Co., model IR100, serial No. 4829, which houses a radioactive source of Ir-192 with serial number TT3561 with a current activity of 1.14 Ci.
The devices were extracted from the facility on March 22, 2023 at approximately 3:00 a.m. (UTC-6) on the address Pánfilo Natera 205, Col. Lázaro Cardenas, Salamanca, Guanajuato, Mexico.
The actions taken were: a) The theft has been reported to the law enforcement agencies; b) The National Regulatory body has notified the National Civil Protection Agency; c) Search for the missing industrial radiography devices is underway; d) A search team of the Regulatory Authority has been dispatched to the site in order to help and advice the responders.2023-03-22T23:19:26+01:002023-03-22T23:19:26+01:00Comision Nacional de Seguridad Nuclear y Salvaguardias, Mexico