NSUF 16-CINR-10200: Feasibility of Combined Ion-Neutron Irradiation for Accessing High Dose Levels
Recently, there have been significant discussions and conference presentations among the utilities, the regulator, the US DOE and industry suggesting the application of ion irradiation to neutron irradiated samples to reach higher dose levels relevant to LWR core components. As light water reactors age, the dose levels of key core structural components (baffle former bolts, flux thimble tubes, springs, core shroud, etc.) are reaching levels at which little data exist. To ensure integrity of these components as well as to consider the possibility of a second life extension to 80 years, or a third to 100 years, it will be critical to know what to expect regarding the behavior of relevant alloys at such high doses. The objective of this proposal is to assess the feasibility and credibility of re-irradiating existing neutron irradiated alloys 304SS and 316SS to high dose levels using ion irradiation. Ion irradiation is playing an increasingly important role in understanding radiation effects in LWR core structural materials. In 2002, the first comprehensive study on the capability of proton irradiation to emulate the irradiated microstructure, radiation hardening and irradiation-assisted stress corrosion cracking (IASCC) susceptibility was published, and showed excellent agreement on all aspects of the microstructure and resulting properties. While highly successful in acting as a surrogate for reactor irradiations, proton irradiation is limited to low to moderate doses (<20 dpa) due to its inherently modest damage rate. There is much less experience with the use of heavy ions to emulate reactor irradiated microstructures. The challenge fundamentally lies in the very high damage rate. While proton irradiation accelerates damage rates relative to that in-core by a factor of 100-300, heavy ion irradiation required to reach the 100 dpa regime requires a damage rate that is over 10,000x that in reactor. It has yet to be established that irradiation conditions can be identified such that in-core radiation damage can be emulated with such high dose rates. An ongoing Integrated Research Program (IRP) sponsored by the US DOE under the NEUP program seeks to answer this question on virgin material. However, it will not address the issue of whether previously neutron irradiated material can be “topped off” with irradiation to reach the target dose range. Such experiments are critical as components for which high dose information is sought generally do not come with virgin material.
Additional Info
| Field | Value |
|---|---|
| Abstract | Recently, there have been significant discussions and conference presentations among the utilities, the regulator, the US DOE and industry suggesting the application of ion irradiation to neutron irradiated samples to reach higher dose levels relevant to LWR core components. As light water reactors age, the dose levels of key core structural components (baffle former bolts, flux thimble tubes, springs, core shroud, etc.) are reaching levels at which little data exist. To ensure integrity of these components as well as to consider the possibility of a second life extension to 80 years, or a third to 100 years, it will be critical to know what to expect regarding the behavior of relevant alloys at such high doses. The objective of this proposal is to assess the feasibility and credibility of re-irradiating existing neutron irradiated alloys 304SS and 316SS to high dose levels using ion irradiation. Ion irradiation is playing an increasingly important role in understanding radiation effects in LWR core structural materials. In 2002, the first comprehensive study on the capability of proton irradiation to emulate the irradiated microstructure, radiation hardening and irradiation-assisted stress corrosion cracking (IASCC) susceptibility was published, and showed excellent agreement on all aspects of the microstructure and resulting properties. While highly successful in acting as a surrogate for reactor irradiations, proton irradiation is limited to low to moderate doses (<20 dpa) due to its inherently modest damage rate. There is much less experience with the use of heavy ions to emulate reactor irradiated microstructures. The challenge fundamentally lies in the very high damage rate. While proton irradiation accelerates damage rates relative to that in-core by a factor of 100-300, heavy ion irradiation required to reach the 100 dpa regime requires a damage rate that is over 10,000x that in reactor. It has yet to be established that irradiation conditions can be identified such that in-core radiation damage can be emulated with such high dose rates. An ongoing Integrated Research Program (IRP) sponsored by the US DOE under the NEUP program seeks to answer this question on virgin material. However, it will not address the issue of whether previously neutron irradiated material can be “topped off” with irradiation to reach the target dose range. Such experiments are critical as components for which high dose information is sought generally do not come with virgin material. |
| Award Announced Date | 2019-12-19T00:00:00 |
| Awarded Institution | None |
| Facility | None |
| Facility Tech Lead | |
| Irradiation Facility | None |
| PI | Zhijie Jiao |
| PI Email | [email protected] |
| Project Type | CINR |
| RTE Number | 3046 |