NSUF 19-1636: Changes in mechanical and chemical-structural properties of gamma irradiated calcium silicate hydrates to an absorbed dose of 200 MGy with respect to pristine samples
The proposed project objectives are to study the changes in viscoelastic behavior, chemical structure and morphology of calcium silicate hydrates after a gamma dose of 200 MGy. Calcium silicate hydrates are considered the glue of cement and hence are important for the stability of the concrete bio-shield in nuclear power plants. The impact of high gamma doses on the viscoelastic properties of calcium silicate hydrates is not fully understood. Results from previous experiments with samples irradiated to 2.24 MGy indicate that there may be a creep reduction with gamma irradiation. The proposed experiment will be a first of its kind to study the impact of a high gamma dose (200 MGy) to inform models that predict the degradation of cement and concrete with irradiation. Since creep has been proven to delay the onset of irradiation damage, a reduction in creep will certainly impact the level of predicted damage. The outcome of the experiments is mainly the production of stress relaxation and creep curves after irradiation, accompanied by the study of chemical-structural properties to understand the factors that may drive the changes in viscous response, such as the loss of water from the interlayer and/or the precipitation of pseudomorphs. The chemical-structural changes will be studied with X-ray diffraction. Morphology and compositional changes will be examined with TEM. Viscoelastic properties will be obtained through stress relaxation and creep nanoindentation experiments. The main goal is to inform irradiation damage predictive models to support the license renewal of the light water reactor US fleet to 80 years of operation. The samples will be available at the end of January, and the experiments will be finished in 3 sessions of 5 days each during April, May and June.
추가 정보
| 필드 | 값 |
|---|---|
| Abstract | The proposed project objectives are to study the changes in viscoelastic behavior, chemical structure and morphology of calcium silicate hydrates after a gamma dose of 200 MGy. Calcium silicate hydrates are considered the glue of cement and hence are important for the stability of the concrete bio-shield in nuclear power plants. The impact of high gamma doses on the viscoelastic properties of calcium silicate hydrates is not fully understood. Results from previous experiments with samples irradiated to 2.24 MGy indicate that there may be a creep reduction with gamma irradiation. The proposed experiment will be a first of its kind to study the impact of a high gamma dose (200 MGy) to inform models that predict the degradation of cement and concrete with irradiation. Since creep has been proven to delay the onset of irradiation damage, a reduction in creep will certainly impact the level of predicted damage. The outcome of the experiments is mainly the production of stress relaxation and creep curves after irradiation, accompanied by the study of chemical-structural properties to understand the factors that may drive the changes in viscous response, such as the loss of water from the interlayer and/or the precipitation of pseudomorphs. The chemical-structural changes will be studied with X-ray diffraction. Morphology and compositional changes will be examined with TEM. Viscoelastic properties will be obtained through stress relaxation and creep nanoindentation experiments. The main goal is to inform irradiation damage predictive models to support the license renewal of the light water reactor US fleet to 80 years of operation. The samples will be available at the end of January, and the experiments will be finished in 3 sessions of 5 days each during April, May and June. |
| Award Announced Date | 2019-02-08T00:00:00 |
| Awarded Institution | Center for Advanced Energy Studies |
| Facility | Microscopy and Characterization Suite |
| Facility Tech Lead | Kory Linton, Yaqiao Wu |
| Irradiation Facility | None |
| PI | Nishant Garg |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 1636 |