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| Entered date | Event description | |
|---|---|---|
| ENS 42962 | 3 November 2006 13:05:00 | This event was received via e-mail On November 1, three workers were involved in separating sources, lead pigs (shielded containers) and trash from a barrel. Work was being conducted in a ventilated enclosure within a PEcoS waste processing building. Two workers inside the enclosure were wearing respirators and the supervisor (not wearing a respirator) was immediately outside the enclosure directing the work. At the end of the day, the supervisor noted he was contaminated. The supervisor was scheduled for whole-body counting at the Battelle facility early the next day. An uptake of approximately 11.7 nanocuries of Americium 241 was confirmed. The preliminary dose estimate to the individual's lung was 97.5 Rem CDE. The individual was started on chelation treatment. The other two workers were sent for whole body counting on November 3. The operation included opening one lead pig that contained three Am-241 sources. Contamination previously had not been detected outside the pig or in the trash. Sources were surveyed for dose rate and separated from the lead pig without contamination smears being taken. No release to the public or the environment occurred. Operations in this and adjacent areas were stopped once the situation was known. An investigation was initiated by PEcoS. The area was evacuated and is currently being ventilated. DOH has an inspector on-site performing an incident investigation. Media is aware of the incident. Notification Reporting Criteria: WAC 246-221-250(2) Notification of Incidents (24 hour notification) Isotope and Activity involved: Am-241 total activity from twelve drums was manifested at 6.8 GigaBq (184 millicuries). Only one drum was open at the time of the incident. Overexposures? (number of workers/members of the public; dose estimate; body part receiving dose; consequence): Three workers were involved. One worker has an apparent over exposure of 97.5 Rem CDE to the Lung. No release to public or environment.
On November 1, three workers were involved in separating sources, lead pigs (shielded containers) and trash from a barrel. Work was being conducted in a ventilated room, (previously reported as an enclosure within the room) within a PEcoS waste processing building. Two workers inside the room were wearing respirators and the supervisor (not wearing a respirator) was immediately outside the room directing the work. A very high contamination level was detected (greater than 2 million dpm/wipe) in the room at about 10:00, and the building was evacuated shortly after that. At about this time, an air sample that was in the area of the workers was counted and determined to have a very high alpha activity (10 E-9 �Ci/ml). The supervisor and the workers were taken to a survey area and found to be contaminated on the face. Contamination was detected on the respirators. The workers were successfully decontaminated by the on site health physics department. The supervisor was scheduled for whole-body counting at the Battelle facility early the next day. An uptake of approximately 11.7 nanocuries of Americium 241 was confirmed. The preliminary dose estimate was 97.5 Rem CDE. The individual was started on chelation treatment. The other two workers were sent for whole body counting on November 3. Subsequent counts on the first individual were lower (about 9nCi), and the subsequent 2 workers follow-up counts decreased from about 6.9nCi to 3.2nCi and from 1.5nCi to 0.5nCi. The final dose received will depend on the efficiency of the chelate treatment and other factors. One additional person who was in the building was analyzed for internal Am-241 contamination, and was found to be <0.092nCi, below the detection limit of the instrument. The operation included opening one lead pig that contained three Am-241 sources. Contamination previously had not been detected outside the pig or in the trash. Sources were surveyed for dose rate and separated from the lead pig without contamination smears being taken. Operations in this and adjacent areas were stopped once the situation was known. An investigation was initiated by PEcoS. The area was evacuated and is currently being ventilated. DOH has an inspector on-site performing an incident investigation. Update as of 14 November: The three employees are still being treated with a chelating agent. This week should be the last week. At this time, there is no update on the original activity or the activity left in the body, except that the amount of activity in the lung is decreasing. It will be several weeks before the final dose can be calculated by the licensee's consultants, which will be based on the initial lung count, the bioassay results (urine/fecal), and the effectiveness of the chelate at removing the americium from the body. At this point, we assume there are three individuals who may have exceeded their annual dose limit of 50 Rem to the bone. The final dose received by the three individuals will be calculated when sufficient information is accumulated. The three workers have returned to work exhibiting some emotional stress and slight effects from the medical treatments. Plant Status The plant is being restarted incrementally after a safety shutdown imposed by the company. After DOH approval, two process lines have been restarted: the super compactor on the mixed waste side of operations and an inspection and sorting process, also on the mixed waste side. The licensee is completing items identified on the mixed waste thermal systems safety evaluation, and expects to restart those processes in the next few days. In addition, they are completing items identified on the low level thermal systems, but a restart date is pending. The low level processes that were affected by this accident are not being restarted, until the contamination in the building is controlled. The building that the material is in is being decontaminated, and continues to be a respirator area. The contaminated room is still inaccessible, however, a plan was completed to re-enter the room to assess the extent of the contamination. This initial entry was conducted on 11-14-06 by senior members of the Health Physics staff. As a result of the surveys conducted during the reentry, the extent of the problem they face is better understood. A plan is being developed to decontaminate the room. The investigation is continuing, and the actual cause of the event does not appear to be a single cause, but rather compounding mistakes, errors in judgment and complacency for the seriousness of this type material. Corrective actions that are being taken by the licensee at this time, are primarily based on self evaluation, using the workers and technical staff. In addition, at this time DOH is requiring the company to retrain the radiological technicians as well as the workers in the different waste processes prior to restart of any process. DOH is working with the company to identify the root causes of this incident. No release to public or environment. Air sample analysis results for a particulate sample in the building exhaust stack was 9.2E-3 �Ci/ml gross alpha. The building is being decontaminated, and additional containment tents are being installed around the contaminated room. Media is aware of the incident. Tri-City Herald (Kennewick Washington) article was published November 4, 2006. Notification Reporting Criteria: WAC 246-221-250(2) Notification of Incidents (24 hour notification) Isotope and Activity involved: Am-241 total activity from twelve drums was manifested at 6.8 GigaBq (184 millicuries). Only one drum was open at the time of the incident. Overexposures? (number of workers/members of the public; dose estimate; body part receiving dose; consequence): Three workers were involved. The first worker had an initial internal deposition result of 11.7 nCi. Two additional workers have been confirmed as having an internal deposition: initial results were 6.9 nCi and 1.5 nCi. Subsequent counts of all three involved personnel were lower. All three workers were given chelating treatment. The final dose will be calculated by the Battelle internal dosimetry program, following extensive testing. Other workers who were in the area are being tested. The estimated dose to the endosteal (white bone matter) from 11.7nCi is about 95 rem CDE. R4DO (Johnson) and NMSS EO (Camper) notified. Washington State Report # WA-06-063.
Update as of 5 February, 2007 From the Department of Health's investigation into this incident, it appears that the root cause of the event was failure to adhere to procedures and plans set forth for the project, and inadequate training. Preliminary corrective actions taken by the licensee to prevent recurrence are disciplinary action to the employees involved for procedure and policy violations, a functional Alpha CAM was put in service, training performed for all staff working with radioactive material, with follow-up testing. Additionally, a reorganization of the facility which relieves the RSO of numerous tasks not related to Radiation Safety has taken place, and the facility has made a new position Special Project Lead who is assigned to work with HP and Operations Staff on special projects and compile lessons etc. The final exposure to the individuals has not yet been assigned. When the DTPA treatments have been determined done then exposures will be able to be assigned. Currently it is anticipated that the final dose calculation will be assigned by the end of February 2007. The amount of Am-241 activity in the involved drum was manifested as 71 millicuries Am-241. R4DO (Nease) & NMSS (Greg Morell) notified.
Update as of April 23, 2007 The final intake and internal dose evaluation of the PEcoS employees have been completed. The results are presented below, along with the anticipated dose they would have received if the employees did not receive the DTPA chelating treatments. Employee 1: Intake was estimated at 17 nCi of Am241 The estimate of the actual 50-year committed internal dose equivalents for the respective organs and tissues "Actual 50-year Committed Anticipated Dose Organ / Tissue Dose Equivalent (rem) Without Therapy (rem) Effective 3.8 7.3 Bone Surface 78 150 Liver 4.6 8.9 Red Bone Marrow 6.2 12 Gonads 1.1 2.1 Lungs 1.7 1.7 Employee 2: Intake was estimated at 4 nCi of Am241 The estimate of the actual 50-year committed internal dose equivalents for the respective organs and tissues "Actual 50-year Committed Anticipated Dose Organ / Tissue Dose Equivalent (rem) Without Therapy (rem) Effective 1.0 1.7 Bone Surface 22 36 Liver 1.3 2.1 Red Bone Marrow 1.7 2.8 Gonads 0.29 0.48 Lungs 0.39 0.39 Employee 3: Intake was estimated at 48 nCi of Am241 The estimate of the actual 50-year committed internal dose equivalents for the respective organs and tissues "Actual 50-year Committed Anticipated Dose Organ / Tissue Dose Equivalent (rem) Without Therapy (rem) Effective 4.9 21 'Bone Surface 95 430 Liver 5.5 25 Red Bone Marrow 7.5 34 Gonads 1.3 5.8 Lungs 4.7 4.7 The licensee has taken the following corrective actions to help prevent reoccurrence: A Re-distribution of the RSO's work to other onsite personnel and hiring additional people to ensure adequate coverage. Management reorganization, to increase the oversight given to the radiation protection program. Increased training on procedures. 'Increased management interaction and surveillance by the RSO and other health physics staff. 'Inclusion of the engineering staff on all facility changes, such as ventilation changes.'Changes to the procedures for operation of the ventilation system in buildings 1 and 2. Hazard analysis on the ventilation system in buildings 1 and 2, and the changes that were discussed in the hazard analysis. Careful analysis of the internal dose received by the affected workers. Assurance PEcoS personnel will follow all of your procedures. Disciplinary action for culpable employees. Greater emphases to ensure that orders and instructions to the workers are clear and understood. Plant Status The plant is being restarted incrementally after a safety shutdown imposed by the company. After DOH approval, two process lines have been restarted: the super compactor on the mixed waste side of operations and an inspection and sorting process, also on the mixed waste side. The licensee is completing items identified on the mixed waste thermal systems safety evaluation, and expects to restart those processes in the next few days. In addition, they are completing items identified on the low level thermal systems, but a restart date is pending. The low level processes that were affected by this accident are not being restarted, until the contamination in the building is controlled. The building that the material is in is being decontaminated, and continues to be a respirator area. The contaminated room is still inaccessible, however, a plan was completed to re-enter the room to assess the extent of the contamination. This initial entry was conducted on 11-14-06 by senior members of the Health Physics staff. As a result of the surveys conducted during the reentry, the extent of the problem they face is better understood. A plan is being developed to decontaminate the room. The investigation is continuing, and the actual cause of the event does not appear to be a single cause, but rather compounding mistakes, errors in judgment and complacency for the seriousness of this type material. Corrective actions that are being taken by the licensee at this time, are primarily based on self evaluation, using the workers and technical staff. In addition, at this time DOH is requiring the company to retrain the radiological technicians as well as the workers in the different waste processes prior to restart of any process. DOH is working with the company to identify the root causes of this incident. No release to public or environment. Air sample analysis results for a particulate sample in the building exhaust stack was 9.2E-3 �Ci/ml gross alpha. The building is being decontaminated, and additional containment tents are being installed around the contaminated room. Media is aware of the incident. Tri-City Herald (Kennewick Washington) article was published November 4, 2006. Notification Reporting Criteria: WAC 246-221-250(2) Notification of Incidents (24 hour notification) Isotope and Activity involved: Am-241 total activity from twelve drums was manifested at 6.8 GigaBq (184 millicuries). Only one drum was open at the time of the incident. Overexposures? (number of workers/members of the public; dose estimate; body part receiving dose; consequence): Three workers were involved. The first worker had an initial internal deposition result of 11.7 nCi. Two additional workers have been confirmed as having an internal deposition: initial results were 6.9 nCi and 1.5 nCi. Subsequent counts of all three involved personnel were lower. All three workers were given chelating treatment. The final dose will be calculated by the Battelle internal dosimetry program, following extensive testing. Other workers who were in the area are being tested. The estimated dose to the endosteal (white bone matter) from 11.7nCi is about 95 rem CDE. Lost, Stolen or Damaged? (mfg., model, serial number): N/A Disposition/recovery: N/A Leak test? N/A Vehicle: (description; placards; Shipper; package type; Pkg. ID number) N/A Release of activity? N/A Activity and pharmaceutical compound intended: N/A Misadministered activity and/or compound received: N/A Device (HDR, etc.) Mfg., Model; computer program: N/A Exposure (intended/actual); consequences: N/A Was patient or responsible relative notified? N/A Was written report provided to patient? N/A Was referring physician notified? N/A Consultant used? (deleted) at Battelle in vivo counter facility, (deleted) at Advanced Medical, and (deleted) at Pacific Northwest National Laboratory. FSME (Greg Morell) & R4DO (Linda Smith). |