b'The fuel fabrication division fabricated a series of small LWR rodlets each using 4.9% enriched UO 2pellets in zirconium alloy cladding and oversaw development of capsule assembly methods. TREAT experiment engi-neering personnel developed and installed experiment supporting system including modernized experiment gas control system and experiment data acquisition systems. This coordinated effort gave way to the first fueled experiment capsule (SETH-A) irradia-tion. Thermocouples were attached to the SETH-A rodlet cladding during this low energy transient whose purposes was to obtain nuclear heating data (expressed as a ratio of specimen-to-core energy deposition, termed energy coupling factor, ECF) by calorimetry Figure 3. Reactor transientdesign was developed, entitled thein-situ. The SETH-A rodlet was later and specimen temperatureseparate effects test holder (SETH),extracted from the capsule and char-data from SETH-D. to enable transient fuel irradiationsacterized by gamma spectroscopy as in inert gas capsules. A series ofanother method of correlating ECF. The SETH irradiations were completed insecond capsule (SETH-B) was irradiated 2019, both to commission TREATsmultiple times to investigate the effect modern experiment capabilities andof increasing transient energy on ECF, to obtain nuclear heating data fromto work out data acquisition parameters LWR specimens in a modern corefor first-of-a-kind use of multispectral configuration. These outcomes werepyrometry, and to refine parameters essential developments in enablingfor operating the refurbish fuel motion experiments on ATF technologies andmonitoring system (FMMS, aka fast water environment capsule (currentlyneutron hodoscope). SETH-C was underway). This inaugural irradiationirradiated a single time at higher campaign paved the way for TREAT toenergy deposition to help explore reclaim its role in fuel safety researchcladding temperature instrumenta-to help develop and license advancedtion response time and range. SETH-C nuclear fuels. also achieved a world first with use of Accomplishments: additive manufacturing to produce the INLs nuclear science and technologyirradiation capsule. The use of additive directorate largely oversaw the design,manufacturing enabled reduced cost predictive analysis, and fabricationin manufacturing the mostly-hallow of irradiation test hardware for thesubsequent capsules while paving the MARCH system and SETH capsules. 116 2019|AFC ACCOMPLISHMENTS'