Comparison of Pad Hardness Study With Drop Test Results

Title 10, Part 71, of the Code of Federal Regulations (10 CFR 71) contains requirements for the construction and operation of spent nuclear fuel and high-level waste transpor~ packagings that are considered prescriptive; e.g., the designer is required to demonstrate, either through performance testing or analysis, that the packaging can withstand a well-defined sequence of hypothetical accident events without exceeding limits on the release of its radioactive material (RAM) contents. The performance testing option is often chosen by designers, even when detailed stress analysis of the packaging containment boundary is performed for the hypothetical accident conditions. Testing of full-scale packagings carries a significant economic penalty, however, both due to cost of the test articles themselves and to the cost of testing at facilities able to handle typical truck and rail casks. Furthermore, the selection of the most damaging orientation is not readily apparent, since a center-of-gravity-over top corner drop may be most damaging for one portion of the containment boundary, while a side drop may be more damaging for another. For these reasons, the use of scale models of the packagings for drop testing is preferred, with full-scale testing reserved for only the most critical of design issues.