This operation will be conducted with the utmost considerations for safety to LANL employees, the surrounding communities, and the environment. The FTWC depressurization remediation plan is designed to eliminate the chance of an uncontrolled, unmitigated, or unmonitored release of radioactive material from the containers.
Current Project Status
Sunday, October 5
Update #3: FTWC #1 has been successfully moved to the Lab’s Weapons Engineering Tritium Facility. There were no emissions from today’s operations. Updates will be provided prior to the next movement operation.
Update #2: The first FTWC has been loaded and is being transported to WETF.
Update #1: We’ve begun field operations for movement of the FTWCs to the Lab’s Weapons Engineering Tritium Facility (WETF). All four FTWCs remain in safe and secure configuration. Updates will be provided throughout the day.
Wednesday, October 1
We will resume FTWC operations this Sunday and are planning to begin to move the FTWCs from Area G to the Weapons Engineering Tritium Facility. Movement does not involve any emissions, although if increased pressure is observed in any container, we will perform additional safe and secure configuration work that could involve emissions. We will provide updates throughout the operation as we have been.
Tuesday, September 30
Safe and secure configuration has been completed on all four FTWCs. The total radiological dose for the operation to date is less than 0.0125 millirem to a hypothetical, maximally exposed individual member of the public at the site boundary using actual monitoring data and actual weather conditions.
During movement activities, the possibility exists that slight pressure could build in the headspace of the container. We will monitor that closely. If any of the containers experience a pressure increase, we will need to mitigate that pressure, and we may see emissions during those operations.
Updates will be provided before movement activities occur.
Monday, September 29
Update #4: The FTWC safe configuration has been completed on the fourth FTWC and we’ve concluded operations for the day. Total tritium emissions for the day’s operations were less than 70 curies, which is less than 0.025 mrem to a hypothetical maximally exposed individual at the site boundary using the real time monitoring data and the bounding weather conditions.
This completes the safe and secure configuration work for all four FTWCs. The next step is to move all four FTWCs, one at a time, to the lab’s Weapons Engineering Tritium Facility (WETF). During movement, the possibility exists that slight pressure could build in the headspace of the container. We will monitor that closely. If any of the containers experience a pressure increase, we will need to mitigate that pressure, and we may see emissions during those operations. We will continue to provide updates throughout the day as we work through the movement stage.
Update #3: Safe and secure operations continue on the fourth FTWC. Emissions so far today are less than 26 curies, which is less than 0.008 mrem offsite to a hypothetical maximally exposed individual at the site boundary using the real time monitoring data and the bounding weather conditions.
Update #2: Safe and secure operations continue on the fourth FTWC. Emissions so far today are less than 13 curies, which is less than 0.0004 mrem offsite to a hypothetical maximally exposed individual at the site boundary using the real time monitoring data and the bounding weather conditions.
Update #1: We’ve begun FTWC operations and will continue work to place the one remaining container in the safe and secure configuration. We will provide updates throughout the day.
Thursday, September 25
Update #4: The FTWC safe configuration has been completed on the third FTWC and we’ve concluded operations for the day. Total tritium emissions for the day’s operations were less than 1.5 curies, which is less than 0.0004 mrem to a hypothetical maximally exposed individual at the site boundary using the real time monitoring data and the bounding weather conditions. Total tritium emissions from the operation so far are less than 53 curies. Using actual weather data and formal analytical results, the calculated off-site dose consequence is less than 0.005 mrem to a modeled/hypothetical maximally exposed member of the public.
We plan to resume Monday, September 29, at 7:00 a.m. to continue operations to get the one remaining FTWC in a safe and secure configuration. We may see emissions during those operations and will continue to provide updates throughout the day. We will not perform FTWC operations from Friday, September 26, through Sunday, September 28, due to forecasted rain.
Update #3: Safe and secure operations continue on the third FTWC. Emissions so far today are less than 0.9 curies, which is less than 0.0002 mrem offsite to a hypothetical maximally exposed individual at the site boundary using the real time monitoring data and the bounding weather conditions.
Update #2: Safe and secure operations continue on the third FTWC. Emissions so far today are less than 0.8 curies, which is less than 0.0002 mrem offsite to a hypothetical maximally exposed individual at the site boundary using the real time monitoring data and the bounding weather conditions.
Update #1: We’ve begun FTWC operations and will continue work to place the remaining two containers in the safe and secure configuration. We will provide updates throughout the day.
Wednesday, September 24
Update #5: The FTWC safe configuration has been completed on the second FTWC and we’ve concluded operations for the day. Total tritium emissions for the day’s operations were less than 10 curies, which is less than 0.0033 millirem offsite using the real time monitoring data and the bounding weather conditions. Total tritium emissions from the operation so far are less than 52 curies. Using actual weather data and formal analytical results, the calculated off-site dose consequence is less than 0.005 millirem to a modeled/hypothetical maximally exposed member of the public.
We plan to resume tomorrow, September 25, at 7:00 a.m. to continue operations to get the two remaining FTWCs in a safe and secure configuration. We may see emissions during those operations and will continue to provide updates throughout the day.
Update #4: Placing the containers in a safe and secure configuration involves slightly pressurizing each FTWC with helium to perform a leak check. That helium is then let out through the capture system and then we apply a slight vacuum to provide additional safety margin. Once all four containers are in safe and secure configuration, we will begin moving them, one at a time, to the Lab’s Weapons Engineering Tritium Facility. This is a very slow and deliberate process to both mitigate any pressure differences inside the containers and to maximize the effectiveness of the capture system. We are committed to minimizing emissions in all stages of the operation.
Update #3:

Update #2: Operations continue. Emissions so far today are less than 2.5 curies. Offsite dose using worst case weather file is less than 0.001 mrem (actual weather file will be lower).
Update #1: We’ve begun FTWC operations, and will continue our work to place the remaining three containers in a safe and secure configuration. We will provide updates throughout the day.
Tuesday, September 23
Update #4: The pressure monitoring manifold leak check has been performed on the fourth FTWC and we’ve concluded operations for the day. Total tritium emissions for the day’s operations were less than 0.25 curies, which is less than 0.0001 millirem offsite using the real time monitoring data and the bounding weather conditions. Total tritium emissions from the operation so far are less than 41 curies. Using actual weather data and formal analytical results, the calculated off-site dose consequence is less than 0.005 millirem to a modeled/hypothetical maximally exposed member of the public.
We plan to resume tomorrow, September 24, at 7:00 a.m. to continue operations to get all four FTWCs in a safe and secure configuration. We may see emissions during those operations and will continue to provide updates throughout the day.
Update #3: Depressurization step is complete on the fourth FTWC. No internal pressure was observed in the container headspace (zero psi). We are continuing in the procedure and may see some emissions as we work through the steps to place the FTWC in a secure configuration. We will continue to send updates on status and any emissions.
Update #2: All prerequisite checks have been successfully completed. We have installed the depressurization manifold on the fourth FTWC and will begin depressurization within the next hour.
Update #1: We’ve begun field operations at Area G, and we’ll be providing updates throughout the day.
Monday, September 22
Update #2: The Lab will resume FTWCs depressurization operations Tuesday, September 23. Updates will be provided throughout the day on progress.
Update #1: Due to rain in the forecast, we will not be performing depressurization activities today. We plan to resume tomorrow.
Sunday, September 21
Update #6: The pressure monitoring manifold leak check has been performed on the third FTWC and we’ve concluded operations for the day. Total tritium emissions for the day’s operations were less than 6 curies, which is less than 0.002 mrem offsite using the bounding weather conditions. Total tritium emissions from the operation so far are less than 41 curies. Using actual weather data, the calculated off-site dose consequence is less than 0.005 millirem to a modeled/hypothetical maximally exposed member of the public.
We plan to resume operations Monday, September 22 at 7:00 a.m. to depressurize the fourth FTWC.
Update #5: Depressurization step is complete on the third FTWC. No internal pressure was observed in the container headspace (zero psi). We are continuing in the procedure and may see some emissions as we work through the steps to place the container in a secure configuration. We will continue to send updates.
Update #4: All prerequisites have been successfully completed. We will begin depressurization of the third FTWC within an hour.
Update #3: One of the prerequisite checks was not satisfactorily met in accordance with the procedure, so we will be pausing to correct prior to resuming operations. Upon successful completion, we will proceed as planned with depressurization of the third FTWC. We will provide another update prior to depressurization.
Update #2: We have installed the depressurization manifold on the third FTWC and will begin depressurization within the next hour.
Update #1: We’ve begun operations for the day, and are preforming equipment set up and prerequisite checks. We plan to depressurize the third FTWC today.
Saturday, September 20
Update #4: The pressure monitoring manifold leak check has been performed, and we’ve concluded operations for the day. Total tritium emissions for the day’s operations were less than 0.12 curies—less than 0.00005 millirem offsite. Total tritium emissions from the operation so far are less than 35 curies. The calculated off-site dose consequence is 0.005 millirem to a modeled/hypothetical maximally exposed member of the public.
Update #3: The pressure monitoring manifold has been installed on the second FTWC. Total emissions from the second FTWC so far today is less than 0.2 curies.
Update #2: Depressurization is now complete. There was no pressure in the container. We are continuing in the procedure and may see some emissions as we work through the steps to place in a secure configuration.
Update #1: All equipment checks have passed, drum lids have been removed, and installation of the depressurization manifold on the second FTWC has been completed. Depressurization will begin in approximately one hour.
Thursday, September 18
In order to service some equipment associated with depressurizing the second FTWCs container and due to expected adverse weather conditions, operations are postponed until Saturday per our schedule.
We’ve had a productive day prepping equipment, incorporating improvements from the successful completion of the first FTWC, and making preparations to resume operations on Saturday. We plan to begin FTWC depressurization operations on the second FTWC on Saturday, September 20. We plan to continue operations on Sunday, September 21, to depressurize the third FTWC. No FTWC operations will be performed on Friday, September 19. Any changes to the weekend plans will be posted.
Wednesday, September 17
Completed operations on FTWC 225 (the first FTWC) with securing and pumping down the pressure monitoring manifold. FTWC 229 (the second FTWC) operations were started, including drum lid removal. Depressurization operations for 229 are planned for September 18. Total tritium emissions for the operation so far is less than 35 curies. The calculated off-site dose consequence is 0.005 millirem to a modeled/hypothetical maximally exposed member of the public. This is an informal/non-official number shared for communication purposes. We will do peer review and validation prior to final reporting.

Tuesday, September 16
Depressurization operations were performed on the first FTWC today, and no internal pressure was found. That indicates that the inner containers in this FTWC had not leaked. Air monitoring indicated no deviation from background levels. Planned operations for Wednesday, September 17, will be the depressurization of the next (second) FTWC.
Monday, September 15
On Monday, September 15, 2025, operations continued at TA-54 Area G for the FTWC pressure mitigation activity. We opened the first overpack container and performed air sampling in the overpack. Preparations were made to install the venting manifold.
Monitoring showed no detectable tritium activity.
We intend to continue pressure mitigation operations on Tuesday, September 16.