Spectroscopic Monitor of Fuel Rod Integrity in Dry Storage Casks

Energy Research Company ERCo), in collaboration with the Safeguards Science and Technology Group at Los Alamos National Laboratory, proposes the development of a monitor of fuel rod integrity in spent nuclear fuel storage casks that utilizes spectroscopic measurements. Currently, dry storage casks are the only storage option for spent nuclear fuel in the United States once the fuel is cool enough to be removed from the spent fuel pool. In the absence of a domestic long term storage site or fuel reprocessing plant, the fuel rods will remain in these casks. However, there is no method for inspecting the integrity of fuel rods over time without opening the casks and removing the rods for inspection. The proposed sensor will allow for determining the integrity of the fuel rods from outside the cask. Gases are released from spent fuel rods that fracture. Since dry storage casks are filled with pure helium, no other gases are present in the cask at the time it is sealed. Detecting other gases inside the cask is therefore equivalent to detecting a failing fuel rod. The spectroscopic monitor will be capable of detecting the small quantities of gases in a cask that would be released from a single fractured rod. The concept will be proven in Phase I by making measurements of a gas that is released by a fractured fuel rod using the proposed spectroscopic method in a realistic optical configuration for a dry storage cask. These measurements will yield the design parameters necessary for designing and building a prototype in Phase II. With the concept proved, we will approach cask manufacturers for collaborations in Phase II and beyond. The direct commercial application is for monitoring dry storage casks at nuclear power stations and other locations. As of 2010, 63 licenses for spent fuel dry storage sites have been issued. The Nuclear Energy Institute predicts that by 2026, all but 3 of the 100 currently operating nuclear power reactors will require dry storage for their spent fuel. In addition to the dry storage cask application, we also plan to utilize the technology developed in this project to improve monitoring of nuclear materials in other contexts.