Accident, conditions for criticality, criticality, dangers of nuclear, Japan, NRC, nuclear energy, nuclear fuel, nuclear fuel chain, nuclear industry, risk management, Safety Culture, scrubber, South Carolina, Toshiba, Toshiba Westinghouse, uranium, USA, Westinghouse
Westinghouse is now a Toshiba (Japan) subsidiary. It is 87% Toshiba owned; 10% Kazatomprom (Kazakhstan State owned), and 3% IHI (Japan) owned. At the same facility within the last year: https://miningawareness.wordpress.com/2016/03/15/dangerous-alpha-radiation-surface-contamination-on-toshiba-shipment-workers-burned-at-toshiba-facility-in-south-carolina-same-facility-separate-events/
The current uranium build-up problem at the Toshiba-Westinghouse nuclear fuel facility in South Carolina has been of concern since the end of May!
Looks ok from the front, but less tidy as one gets to the backside, it seems.
“On July 13, 2016, it was determined by the Environment, Health and Safety (EH&S) department that scrubber clean-out material, found in the S-1030 scrubber transition section during the annual maintenance shutdown that occurred in late May, potentially exceeded the uranium mass limit for the scrubber transition.”
On August 1st the US NRC said: “There were no actual safety-related consequences as a result of the accumulation of the material, but the potential for such consequences may have existed…
This incident did not involve employee contamination or a nuclear criticality, but it shows the need for Westinghouse management to review some aspects of their operation,” said NRC Region II Administrator Cathy Haney. “Our inspection will evaluate these issues thoroughly and ensure they are being properly addressed.” http://www.nrc.gov/docs/ML1621/ML16214A334.pdf (see entire notice at bottom of this post)
On August 12th: “There were no actual safety-related consequences as a result of the accumulation of the material, but the potential for such consequences may have existed. After an analysis showed the amount of uranium was much higher than anticipated, the NRC launched an inspection to review the issue.
The still-ongoing inspection prompted the need for the Confirmatory Action Letter, or CAL, which outlines a series of corrective actions Westinghouse has already taken or will perform before NRC-licensed operations involving the scrubber system can be resumed. A copy of the CAL will be placed on the NRC website and is available from the NRC’s Region II Office of Public Affairs.
Those actions include shutting down affected systems in the facility, performing a root cause analysis investigation of the event, conducting a review and revision of safety culture, updating maintenance and management procedures, installing physical modifications to the system, training personnel operating and maintaining the system, reviewing other potentially affected systems, and retaining an external nuclear criticality safety expert to oversee such functions” http://www.nrc.gov/reading-rm/doc-collections/news/2016/16-032.ii.pdf (see entire notice at bottom of this post)
“Fuel Cycle Facility
Event Number: 52090
Facility: WESTINGHOUSE ELECTRIC CORPORATION
RX Type: URANIUM FUEL FABRICATION
Comments: LEU CONVERSION (UF6 to UO2)
COMMERCIAL LWR FUEL
City: COLUMBIA State: SC
License #: SNM-1107
NRC Notified By: NANCY PARR
HQ OPS Officer: DONG HWA PARK
Notification Date: 07/14/2016
Notification Time: 18:49 [ET]
Event Date: 07/13/2016
Event Time: [EDT]
Last Update Date: 07/31/2016
Emergency Class: NON EMERGENCY
10 CFR Section:
PART 70 APP A (a)(4) – ALL SAFETY ITEMS UNAVAILABLE
DANIEL RICH (R2DO)
DEGRADED SAFETY ITEMS CAUSED BY URANIUM BUILDUP
“On July 13, 2016, it was determined by the Environment, Health and Safety (EH&S) department that scrubber clean-out material, found in the S-1030 scrubber transition section during the annual maintenance shutdown that occurred in late May, potentially exceeded the uranium mass limit for the scrubber transition.
“(IROFS [Items Relied on for Safety] VENT-S1030-110) requires annual inspection and removal of significant solids buildup in the transition section. Upon inspection, significant buildup was found, and the ductwork was opened to permit extensive cleanout. 36 containers of material with a total gross weight of 210.4 kg was removed from the inlet transition during the cleanout on May 28th to May 29th. Grab samples were subsequently taken from each container and analyzed for uranium concentration. On July 13th, the EH&S department was made aware that the grab sample results averaged 47.8% U. Although the exact uranium mass cannot be determined until the material is dissolved and representatively sampled, available evidence suggests that the mass limit of 29 kg U in the inlet transition was exceeded. The 29 kg U limit is based on an optimally moderated, fully reflected spherical geometry which very conservatively bounds the conditions in the inlet transition of the scrubber. IROFS remained to limit the quantity of uranium available to the scrubber (IROFS VENT-S1030-101, -102, -103 & -104), which are physical barriers designed to minimize uranium in the airflow entering the transition area. Continuous liquid spraying in the inlet transition section to limit solids accumulation (IROFS VENT-S1030-109) was also in place.
“The inlet transition and scrubber were thoroughly cleaned, and the uranium bearing solids were placed into favorable geometry containers. Also, the inspection and cleanout of the transition frequency was increased to monthly.
“Based on available but degraded IROFS, this accident sequence was unlikely. Therefore, this mass accident sequence does not meet the performance requirements of 10CFR70.61. The actual configuration remained safe at all times. Also, no external conditions affected the event.
“Immediate Corrective Actions:
NRC Region II personnel, who were onsite at the CFFF [Columbia Fuel Fabrication Facility], were made aware of the discovery.
“The Conversion area was shutdown to plan for a second extensive scrubber clean-out to validate that the accumulation of solids is a slow buildup over time. The last extensive cleanout was performed in 2009.
“An extent of condition was performed to determine if other scrubbers potentially had significant uranium buildup. Inspection data indicated that this material accumulation issue was limited to the S-1030 scrubber.
“This event has been entered into the facility Corrective Action Prevention And Learning system (CAPAL) #100397353.”
* * * UPDATE PROVIDED BY NANCY PARR TO JEFF ROTTON AT 1025 EDT ON 07/26/2016 * * *
“Onsite chemical analysis confirmed that uranium mass limit for the scrubber transition piece was exceeded. The accumulated material contained 87 kgs of Uranium.
“The Criticality Safety Evaluation for this system was revised and implemented on July 20, 2016 to add Items Relied on For Safety to prevent recurrence of a mass exceedance while the causal analysis and additional corrective actions are completed.”
Notified R2DO (Nease) and NMSS Events Notification Group via email.
* * * UPDATE PROVIDED BY NANCY PARR TO HOWIE CROUCH AT 1749 EDT ON 07/31/2016 * * *
“On July 31, 2016, it was determined by the Environment, Health and Safety (EH&S) department that clean-out material found in the S-1030 scrubber packing and floor also potentially exceeded the uranium mass limit for the scrubber criticality safety evaluation. Over years of operations, the same available but degraded mass prevention and inspection/clean-out IROFS did not prevent exceedance of the mass limit.
“This report is being upgraded to a 1 Hour Event Notification based on 10CFR70 Appendix A(a)(4).
“There was no consequence to the public, the workers or the environment.
“The scrubber process will remain in a safe shutdown mode until further investigation and corrective actions are completed.”
Notified R2DO (Rose), IRD (Grant), NMSS EO (Kotzalas) and NMSS Events Notification via email“.
170 workers of 1000 are being temporarily laid off: https://agrdailynews.com/2016/08/12/feds-investigating-unapproved-buildup-of-nuclear-material-at-columbia-atomic-fuel-factory-the-state/