Deposition distribution curve of Cs element on the inner wall of quartz tubes after 1-hour release tests at 1500°C and 2000°C

The generation process of this experimental dataset aims to simulate the deposition of Cs fission products released during severe nuclear power plant accidents. Starting with a CeO₂ matrix that matches the crystal structure of UO2, 0.52% CsI and other simulated fission product components were added. The samples were prepared by spark plasma sintering (SPS) at 1100°C for 2 minutes, corresponding to a burnup of 76 GWd/t. Subsequently, high-temperature release tests were conducted at 1500°C and 2000°C for 1 hour each in an induction heating test apparatus. After Cs volatilization, it deposited on the inner wall of the quartz tube and downstream pipelines. Laser-induced breakdown spectroscopy (LIBS) with a wavelength of 1064 nm and a resolution of 0.05 nm was used for three-dimensional characterization. The quartz tube was scanned axially with a step size of 5 mm and rotated 90° circumferentially. Intensity data for the Cs characteristic peak at 852.11 nm were collected. Each set of data was integrated for 100 ms over 50 repetitions. Downstream pipelines were also disassembled for inspection. The dataset covers the high-temperature release process for 1 hour under both conditions, with a spatial range extending from the crucible heating zone to the downstream gas pipelines within the fission product release test apparatus. The spatial resolution is 5 mm axially and 90° circumferentially, enabling three-dimensional characterization of Cs deposition on the inner wall of the quartz tube. The table data includes a list of simulated spent fuel components (atomic proportions of 12 elements, no units) and results from post-high-temperature release tests on the upper tube seat. There are 6 records in total, with row labels indicating the sequence numbers of three repeated tests under each condition, and column labels indicating release conditions, test sequence numbers, and Cs element intensity, measured in spectral counts. In terms of data integrity, all measurement points within the 0-150 mm axial range of the quartz tube were covered, and no Cs was detected in the downstream pipelines (Detection limit < 0.1 μg/cm²), indicating no missing core data. Data errors mainly stem from the matrix effect and spectral noise in LIBS measurements. At 1500°C, the standard deviation of Cs intensity was 612.3 counts, with a relative deviation of 29.9%; at 2000°C, the standard deviation was 732.1 counts, with a relative deviation of 8.7%. Sources of error include uniformity of simulated spent fuel components, temperature control fluctuations, and deviations in the position of the LIBS laser focus. The data files consist of two types: one contains information on simulated spent fuel components, recording the atomic proportion parameters of 12 simulated elements, corresponding to a spent fuel composition designed for a burnup of 76 GWd/t; the other contains data from Cs deposition tests, including Cs intensity counts at various axial positions and circumferential angles of the quartz tube under different temperature conditions, as well as qualitative detection results for downstream pipelines. This data supports analysis of Cs deposition patterns and model validation.