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Energy and Environment Directorate

Research Capabilities

Nuclear Reactor Disablement: From Beaker to Deployable System

PNNL researchers successfully developed the technology and associated equipment to neutronically poison and permanently disable graphite moderated reactors. The project required the development of an effective poison and an innovative poison delivery system that assured reactor disablement was safe, fast to apply, low cost, and resistant to countermeasures. Additional boundary conditions were that the disablement approach could not interfere with subsequent verification activities. The following images are from the Reactor Disablement Program showing scale up from bench- to full-scale implementation.

Nuclear Reactor Disablement

Left: Typical graphite moderated reactor shown with PNNL-designed poisoning system. Top-middle: Graphite coupon being tested in a beaker for absorption data. Bottom-middle: Workers testing prototype equipment in the laboratory. Right: Full-height graphite column (seven-story tower) for a training exercise of PNNL-designed equipment.

PNNL staff characterized a variety of different target graphite materials and developed a suitable poison. Staff then designed and built both a primary and a back-up delivery system and evaluated the performance of both at laboratory and at full-scale. The full-scale exercises included assembling a graphite fuel channel and associated reactor core internals that simulated the expected in-field configuration. After the testing facilities were assembled, the staff conducted exercises to demonstrate system viability and effectiveness as well as train the deployment team. Subsequent testing of the graphite blocks verified the effectiveness of both delivery systems to deliver sufficient poison to achieve mission goals. The end result was a fully operational, field-deployable, delivery system capable of permanently disabling graphite moderated nuclear reactors.

Energy and Environment

Core Research Areas