DEFENSE NUCLEAR FACILITIES SAFETY BOARD

January 26, 2024

TO: Katherine R. Herrera, Acting Technical Director

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

SUBJECT: Savannah River Site Activity Report for Week Ending January 26, 2024

Fast Critical Assembly (FCA): SRNS initiated their readiness assessment of H-Canyon’s 

preparedness to successfully execute the FCA campaign. The FCA campaign required the 

installation of an electrolytic dissolver to dissolve the stainless-steel clad components in addition 

to developing new procedures to control receipt, unpackaging, and dissolution of the FCA 

material. The resident inspectors observed several portions of the FCA evolution demonstration 

and interviews. The readiness assessment team will out-brief the facility on their findings and 

opportunities for improvement next week. Once pre-start findings are resolved, DOE-SR will 

commence their federal readiness assessment of the FCA campaign.

L-Area: L-Area personnel identified two separate procedure compliance issues associated with 

the unpackaging of two casks (of the same design) that occurred on two different shifts. On one 

shift, the operations personnel were tasked with venting the cask when they failed to remove and 

inspect a gasket per the procedure. The other issue involved using the incorrect rigging assembly 

to lift the cask lid. The cask handling procedure implements credited criticality safety controls to 

prevent a lid from falling and impacting the fuel assemblies inside the cask, resulting in an 

unanalyzed configuration. The criticality safety controls specifically require that the rigging be 

installed and then verified correct (by the Person-in-Charge of the lift) as specified in the cask 

handling procedure. However, operations personnel failed to recognize that they did not have 

the appropriate keeper hooks on hand for lifting the lid. Instead, they used shackles, which was 

consistent with the previous procedure revision. According to SRNS personnel, due to this 

specific cask’s geometry, a drop of the lid could not impact the fuel inside the cask, thus there 

was no credible criticality event that could be initiated by a dropped lid for this cask design.

Savannah River National Laboratory (SRNL): Control room personnel received a low-level

alarm for the fire water storage tank water level indicator during a cold evening last weekend. 

Based on experience and system knowledge, the shift operations manager (SOM) began entering 

the appropriate limiting condition for operation (LCO) for the safety significant low-low level 

alarm. Shortly thereafter, the low-low level alarm came in and SRNL personnel took the 

appropriate actions. An investigation revealed that cold temperatures caused this failure, similar 

to the event that occurred on 12/23/2022 (see 1/13/2023 report). As part of the corrective actions 

from the failure in 2022, site services performed an inspection of the heat trace on the level 

indicator equipment as part of their annual preventative maintenance. In addition, site services 

inspected the heat trace days before the cold weather, found no issues, and installed additional 

insulation. After the recent failure, inspection revealed that the heat trace was attached and 

functioning properly. SRNL and site services personnel are evaluating additional actions they 

can take to prevent further freeze issues prior to the next anticipated cold weather. In addition, 

they are evaluating more robust, permanent solutions.