Abstract
Accelerated radiation-induced embrittlement of the High Flux Isotope Reactor (HFIR) surveillance materials has been investigated since its discovery in 1986. Recent comprehensive dosimetry experiments revealed the presence of an intense gamma field at the HFIR surveillance locations near the pressure vessel. Gamma-induced reactions were found to dominate the response of several dosimeters and were crucial for the explanation of dosimetry results. This finding precipitated an assessment of the gamma-induced displacements-per-atom (dpa) rate, which was found to exceed the neutron-induced dpa rate at all locations analyzed. When the sum of neutron and gamma dpa is used for the interpretation of the HFIR surveillance results, the HFIR data are consistent with data from the Oak Ridge Research Reactor (ORR) and other test reactors. The accelerated embrittlement is therefore explained in terms of hitherto uncounted dpa induced by gamma rays.
| Original language | English |
|---|---|
| Pages (from-to) | 258-268 |
| Number of pages | 11 |
| Journal | Journal of Nuclear Materials |
| Volume | 217 |
| Issue number | 3 |
| DOIs | |
| State | Published - Dec 1994 |
Funding
* Research supported in part by the Office of Nuclear Regulatory Research, US Nuclear Regulatory Commission, under Interagency Agreement 1886-8255-2L with the US Department of Energy and in part by the Division of Materials Sciences, US Department of Energy under contract DE-AC05840R21400 with Martin Marietta Energy Systems, Inc. The authors wish to express their appreciation to R.K. Nanstad and R.E. Stoller for their comments and suggestions while reviewing this paper. The authors gratefully acknowledge the programmatic support of M. Mayfield and R.E. Johnson from the Office of Nuclear Regulatory Research, US Nuclear Regulatory Commission (NRC). The encouragement to write this paper from A. Taboada and C.Z. Serpan of NRC is appreciated.