PNNL

Bench-scale testing of the vapor monitoring and detection system included controlled releases of both smoke and chemicals of interest into a small area outside a PNNL lab. Tests took place under varying weather conditions to see if the sensors picked up the release and how well the modeling software located the point of release and size of the plume. For more details, see this video by WRPS. Enlarge Image

A new system to monitor and detect chemical vapor releases at the Hanford Site tank farms took a positive step forward recently as researchers from PNNL and the tank farms operations contractor Washington River Protection Solutions wrapped up the first phase of system testing. The effort is part of a multi-million dollar Department of Energy plan focused on further improving worker safety at the tank farms, where millions of gallons of waste from legacy nuclear weapons production are being held in underground tanks awaiting treatment and long-term storage.

The system would constantly monitor the tank farms for vapor releases using different types of field sensors and other equipment, such as infrared cameras. The data would go to a software program that would use any detected releases and weather conditions in a real-time model to show where the release came from, how much was released, what chemicals were detected, and how big of an area was affected. Tank farms staff could use this information to help guide the response effort.

"The objective right now is to figure out if all of this is equipment is going to work together to detect a release and give you the data you need," said Julia Flaherty, task lead for the PNNL team involved in the tests.

The first phase of testing was performed at bench scale—smaller scale and more controlled conditions than the actual tank farms—over several months at PNNL’s Interdiction Technology and Integration Laboratory. In various weather conditions, researchers tested the system with controlled releases of both smoke and key chemicals to represent a potential vapor release at the tank farms, with the sensors and other equipment arranged in different configurations around the release point.

Results and lessons learned from these tests will help the team move on to pilot-scale tests at the tank farms this summer, where they will assess the system under site conditions. “In addition to the bench-scale equipment, the next phase of testing will involve more and additional types of instruments,” said Flaherty.

PNNL will continue to support testing into the pilot phase, helping to deploy the equipment in the field and resolving issues with the equipment, among other things, according to Flaherty.

PNNL Team: Tom Brouns (project manager), Julia Flaherty (task lead), Randy Kirkham, Khris Olsen, Janelle Downs, Jonathan Thomle, Tim Stewart, Elizabeth Golovich, and Carmen Arimescu.