DEFENSE NUCLEAR FACILITIES SAFETY BOARD

March 1, 2024

TO: Timothy J. Dwyer, Technical Director

FROM: L. Lin, Z.C. McCabe, and E.P. Richardson, Resident Inspectors

SUBJECT: Savannah River Site Activity Report for Week Ending March 1, 2024

Staff Activity: Members of the Board’s staff Q. Boney, J. Flora, D. Montierth, and R. Wu were 

onsite to perform preparations for upcoming reviews at H-Canyon and the Defense Waste 

Processing Facility (DWPF). P. Natividad and E. Tetteh were onsite to complete Radiological 

Worker requalification. J. Abrefah was onsite to attend the annual Material Identification and 

Surveillance conference at the Savannah River National Laboratory.

H-Canyon: After identifying numerous errors and omissions related to critical safety limits and 

safety basis related procedures, DOE has suspended the Fast Critical Assembly federal 

Readiness Assessment for the Safety Basis and Criticality Safety functional areas. Overall 

readiness cannot be declared until the two problem areas are reperformed. Due to the number of 

issues identified, SRNS plans to revise the H-Canyon safety basis and re-submit it to DOE.

DWPF: A control room operator added sodium permanganate to a process vessel without using 

the required procedure and then falsified records related to the event. SRMC self-identified the 

issue using plant data and addressed the employee performance issue. This event occurred 

despite DWPF being in a deliberate operations mode since 10/9/2023 following an extended 

series of conduct of operations events.

L-Area: A 20-ton research reactor cask holding uranium-based spent nuclear fuel fell 

approximately 1.5 meters off a flatbed truck as it was being moved within L-Area. The cask 

meets the requirements of Type B shipping container and is designed to withstand a drop from 9 

meters. Thus, L-Area personnel and the cask owners do not expect the fall to challenge the 

integrity of the cask. Personnel have not detected any contamination in the accessible areas 

outside the cask and there were no injuries. Since they were unable to survey under the cask, LArea personnel posted the area immediately around the cask as a contamination area with <1000 

dpm beta/gamma and <200 dpm alpha contamination as a precaution. Additionally, they placed 

a tarp and sandbags over the cask. L-Area is not staffed during the back shift, however, K-Area 

personnel performed surveys of the area every four hours during the backshift to monitor for 

contamination. SRNS personnel have established a “war room” to plan recovery actions to work 

concurrently with the formal investigation they have initiated. All cask movements, including 

the recovery actions, are on hold until the investigation is completed. The efforts currently 

underway include developing a preliminary critical lift plan for the recovery of the cask, 

developing supporting structural mechanical calculations to ensure the abnormal lift can be 

successfully performed, investigating the ground surrounding the cask with ground-penetrating 

radar to detect any underground utilities that might be impacted by a heavy crane, and 

developing a plan for soil and groundwater sampling. An added complication is a similar cask is 

currently in the facility transfer bay with the lid bolts removed. This other cask will likely need 

to be processed prior to the completion of the recovery actions which will include inspection of 

the fuel elements within the fallen cask in the transfer bay.