| 摘要 |
The present invention relates to a nuclear fuel rod structure for improving critical heat flux of heavy-water reactor fuel bundle. More specifically, the nuclear fuel rod structure comprises: a center rod (10); an inner ring (20) which includes six nuclear fuel rods surrounding the center rod (10); an intermediate ring (30) which includes 12 nuclear fuel rods (FR) surrounding the inner ring (20); and an outer ring (40) which includes 18 nuclear fuel rods (FR) surrounding the intermediate ring (30), wherein the minimum distance between the adjacent nuclear fuel rods (FR) of each ring is 1.8 mm, the minimum height based on a space for preventing contact between the nuclear fuel rods (FR) of the intermediate ring (30) and the nuclear fuel rods (FR) of the adjacent outer ring (40) is 0.64 mm, the radius of the intermediate ring (30) from the center of the center rod (10) is variable, and the ratio of a reference radius (D1) from the center rod (10) to the intermediate ring (30) and a maximum variable radius (D2) of the intermediate ring is 1:1.0174. In other words, according to the present invention, when a flow path sectional area of the inner ring is increased to improve critical heat flux generated around the center rod of the heavy-water nuclear fuel bundle, the critical heat flux is further improved through change in diameter of the intermediate ring, the critical heat flux is improved by finely changing the positional structure of the nuclear fuel rod. Accordingly, there is no change in the sectional area of the entire flow path, and thus the level of safety of the existing nuclear reactor is maintained or improved. |
