The long-term stability and performance of Portland cement concrete in nuclear power plants is of concern, as little operational or experimental data exist to aid regulators in extending operating licenses. More complete knowledge of performance in radiation environments will determine concrete’s role in setting the upper limits for lifetime extensions. In the proposed project, concrete, aggregate, and paste samples will be irradiated with energetic protons to simulate radiation damage. A combination of nanoindentation and microhardness techniques will be used to determine the possible reduction in mechanical properties as a function of radiation exposure. Novel non-destructive testing will be used to correlate acoustic and optical properties to any measured hardness changes. This data will be further compared to volatile species evolution during the irradiation. Collected results can be used to determine possible radiation induced degradation in the current fleet, as well as aid in developing radiation tolerant concrete recipes for future plants and storage containers. The proposed work would occur over two 4 day sessions; the first session to occur late April or early May, while the second session occurring ~8 weeks later. A two session approach is necessary as such limited data exists on the radiation response of concrete, particularly in vacuum. Irradiated samples from the first session would be immediately characterized, allowing for a more targeted approach for the second session. In addition to elucidating the radiation tolerance of concrete, the investigation will develop protocol for future irradiations of hydrated materials.

Concrete is currently deployed in commercial light water reactors and proposed as a primary material for new nuclear reactor construction as foundation support, shielding and containment. To date, limited knowledge exists on the influence of radiation on the structural integrity of these concrete components. Understanding the radiation tolerance of concrete is vital to extending the lifetime of the Nation’s present nuclear infrastructure; ultimately this knowledge is required to provide reliability estimates for the long-term safe operation of LWRs. Furthermore, developing a fundamental understanding of the irradiation-microstructure-mechanical relationship for concrete will aid in the development of future concrete mixtures for next generation nuclear reactors. This proposal endeavors to extend accelerated aging techniques previously developed for other critical plant components, onto the complicated concrete system. Using ATR capabilities, it is possible to introduce radiation damage normally acquired over decades in a matter of hours. We propose to simulate radiation damage in concrete, a composite material, as well as its individual components, paste and aggregate, using ion irradiation from particle accelerators. Results will indicate how the strength of concrete is affected from varying degrees of radiation exposure. The more detailed investigation of the individual components, such as the aggregate material, will lead to a database on the radiation tolerance of individual components which could be utilized to develop a susceptibility matrix to structural performance degradation of specific concrete mixtures currently in deployment. The research proposed in this project will have broad reaching impacts in the nuclear energy landscape. Specifically, the project is directly aligned with efforts within the DOE light water reactor sustainability (LWRS) program to assess material degradation issues to the long-term operation of the current nuclear power reactor fleet. Furthermore, information gained under this effort will assist plant designers in developing optimized concrete for radiation tolerance and structural performance for emerging advanced reactor designs.