DNDO Identifies Helium-3 Replacements for Neutron Detection

Posted by: Warren Stern, Director of the Domestic Nuclear Detection Office

Last month, the Department of Homeland Security (DHS) Domestic Nuclear Detection Office (DNDO) completed final analysis on Helium-3 alternatives for neutron detection in radiation portal monitors, which are used to detect illicit radiological and nuclear materials.

Currently, Helium-3 is a necessary component of radiation portal monitors for neutron detection.  However, in recent years, our country has faced a Helium-3 shortage. 

Helium-3 is found in nature and can be harvested from the decay of elements commonly found in nuclear weapons and heavy water reactors.  However, with the drawdown of our nuclear weapon stockpile and the increased usage of He-3 in other applications, such as medical imaging and diagnostics, low temperature (cryogenics) research, and oil/gas exploration, annual Helium-3 demand now outpaces production.

For years, DNDO has been exploring options for an efficient, cost-effective strategy to address the Helium-3 shortage. DNDO’s Neutron Detector Replacement Program is working to decrease the use of Helium-3 in radiation monitors, and is engaging with the private sector to find a commercial alternative to Helium-3.

In August 2011, DNDO concluded an independent government test at our Radiological and Nuclear Countermeasures Test and Evaluation Complex in Nevada to evaluate the performance of several alternative neutron detection modules for radiation portal monitors that do not consume Helium-3. These promising alternative neutron detection technologies will eventually help eliminate the need for new Helium-3 allocations for radiation portal monitors, and alleviate the overall shortage for many government programs.

DNDO is also funding long-term research and development in partnership with the private sector and academia, and has approximately 15 different technologies in the pipeline that could replace Helium-3.

By decreasing the demand and managing the supply, the Obama administration has successfully increased the government’s Helium-3 gas reserve from 25,000 liters in 2009 to approximately 60,000 liters today.

In September, DHS recognized DNDO Test Scientist John Blackadar, as part of the Faces of Homeland Security initiative, for his work on radiological and nuclear detection systems and efforts to address the nation’s Helium-3 shortage.