2018 | ANNUAL REPORT 115 Figure 3. Second stage of cutting after ultrasonic and density measurements were completed on the three- dimensional hex-coin, with measured densities of each piece shown. Slice 3D1 is an iso-dose (28 dpa) strip such that the only variable is the temperature which peaks near the center. Both microscopy and density measurements confirm that void swelling peaks in the center of the strip. The NSUF inventory contains a number of intact, uncut coins. Previous studies on hex blocks have involved the University of Wisconsin, University of Michigan, Boise State University, University of Pittsburg, Massachusetts Institute ofTechnology, Texas A&M, Purdue University, CAES, Electric Power Research Institute, MicroXact Inc., Radiation Effects Consulting, LLC, INL, Oak Ridge National Laboratory, Pacific Northwest National Laboratory, as well as two Japanese entities, the University of Tokyo and Nuclear Fuel Industries- Osaka.A wide range of mechanical, microstructural, microchemical, and dimensional studies have been conducted by these groups. Results of these studies are available to guide the definition and interpretation of new studies, and are listed below. Other publications are in preparation. Currently ongoing studies include welding-induced crack formation, scanning electron microscopy of deformation-induced phase stability, laser and acoustic interrogation of radiation-induced microstructure, non-linear ultrasonic testing of microstructure, and subsequent ion irradiation on neutron-preconditioned specimens.A full description of the available specimen inventory and current location of each specimen can be found on the NSUF website. Accomplishments In typical PWRs, the structural components range from ~2–4 cm in thickness and experience significant gradients in neutron-flux spectra, dpa, temperature, and helium genera- tion, potentially producing complex internal distributions in void swelling. The development of new experimental