DEFENSE NUCLEAR FACILITIES SAFETY BOARD

February 9, 2024

TO: Katherine R. Herrera, Acting Technical Director

FROM: B. Caleca, P. Fox, N. Huntington, and P. Meyer, Resident Inspectors

SUBJECT: Hanford Activity Report for the Week Ending February 9, 2024

Radiochemical Processing Laboratory (RPL): Contractor management completed their root 

cause analysis of unaccounted radioactive material inside RPL hot cells and have successfully 

accounted for all material (see 10/27/2023 report). As part of an extent of condition, personnel 

initiated an inventory review using the facility’s radioactive materials tracking (RMT) database,

which implements a facility specific administrative control for material-at-risk and fissile 

materials. During this inventory, a worker noted a can of material in the Shielded Analytical 

Laboratory hot cells that was not in the RMT database. The facility promptly responded and 

declared a technical safety requirement violation. A resident inspector attended the critique, 

where participants noted that the inventory method used only verifies that all items logged in the 

database can be located but does not require workers to verify all material is associated with an 

RMT entry. As a result of the event, facility management issued standing orders to pause all 

work and material movements requiring RMT pending recovery actions.

242-A Evaporator: While implementing a procedure to switch the evaporator into a 

recirculation status, night shift operators inadvertently caused a pressure transient that activated 

an interlock, which dumps the contents of the evaporator vessel. Facility management noted that 

the shift log did not adequately capture what occurred and the operator turnover did not properly 

communicate the cause of the trip, hindering recovery actions. A resident inspector observed 

management discussing the event with day shift operators and reinforcing expectations for logkeeping and procedure adherence. Facility personnel believe multiple steps in an operating 

procedure were not performed, and that operators had not used place keeping when performing

the procedure. Contractor personnel have initiated an event investigation.

Test Bed Initiative (TBI): A WRPS Joint Review Group (JRG) determined that a work 

package, which a work team will use to install the TBI mast assembly into double-shell tank SY101, is ready to support safe accomplishment of the work. The TBI mast assembly includes the 

pump, filter, and ion exchange column. The work package will also remove existing equipment 

from the selected tank riser and install an adapter that reduces the size of the riser opening to 

match the TBI mast configuration. The JRG also determined that the Field Work Supervisor 

(FWS) and backup FWS candidates were adequately prepared to lead the effort.

Low Activity Waste Facility: A resident inspector observed an evaluated drill conducted by the 

contractor’s emergency planning and response team. The scenario presented to the crew 

involved an ammonia release in the ammonia skid room resulting from a failed gasket, and 

subsequent exposure of two commissioning technicians. The response of the facility emergency 

response organization was prompt, demonstrating marked improvement from previous drills (see 

6/23/2023 report). The drill response was generally well executed. Areas for improvement 

identified and openly discussed in the post-drill hotwash included assuring the availability of 

checklists, completion of abnormal operating procedures, interfacing with emergency responders 

at the event scene, and developing recovery plans.