Holtec International's HI-STAR 180 transport cask has weathered the impact of a missile travelling at around 600 miles per hour, with no breach of containment boundary.
The test was carried out as part of the Swiss nuclear regulator's storage certification process, and was designed to simulate the impact of a crashing aircraft on the HI-STAR 180 transport cask while in use as a spent fuel storage device, Holtec said.
It was carried out by the US Army's missile launcher and witnessed by Swiss customer Axpo, which operates the Beznau nuclear power plant, as well as the Swiss regulator, ENSI, and the Swiss Association for Technical Inspections (SVTI).
Holtec said that the location of impact was precisely that determined to impart the maximum stress levels on the containment boundary and to conservatively challenge the cask containment (to induce leakage of the cask's contents).
After being hit the HI-STAR 180 cash went tumbling into a catch box just as intended by test engineers, Holtec said.
The post-impact inspection of the cask showed that it weathered the impact with "large performance margins." The measured post-impact helium leak rate from the cask's containment boundary, as confirmed by SVTI, was 1000 times smaller than the established acceptance criteria, Holtec said.
Holtec also confirmed that all of the body bolts in the containment boundary of the cask remained elastic and there was no breach of the containment boundary.
Fourteen of the HI-STAR 180 dual-purpose transport and casks, will be built at the Holtec Manufacturing Division (HMD) in Pittsburgh, following certification from ENSI.
Caption: The HI-STAR 180 lying in the catch bin following the test (Source: Holtec)