That accusation seems a little extreme. The 30 day claim was published in January 2012 in response to the Fukushima accident: https://www.tandfonline.com/doi/a

That accusation seems a little extreme. The 30 day claim was published in January 2012 in response to the Fukushima accident: https://www.tandfonline.com/doi/abs/10.13182/NT12-A13556 https://www.tandfonline.com/doi/abs/10.13182/NT12-A13556 Also, in "NuScale Technical Report Long-Term Cooling Methodology, dated January 2017, TR-0916-51299" (https://www.nrc.gov/docs/ML1835/ML18355A973.pdf https://www.nrc.gov/docs/ML1835/ML18355A973.pdf) "5.3.4 Long Term Cooling Evaluation Period LTC analysis is limited to three days. This timeframe is considered acceptable because: (1) the most severe conditions will have been captured within the 72 hour window analyzed, and any conditions that could reasonably be expected to occur beyond this time period are thus bounded by the 72 hour calculation, and (2) after 72 hours, operator actions can be credited. When realistic initial operating levels, temperatures, and decay heat are considered, the scope of the LTC analyses bound the expected level decrease in the reactor pool ultimate heat sink over 30 days, for up to twelve modules transferring decay and residual heat to the reactor pool." I read this as that they ran a number of scenarios with extreme initial conditions and at the end of three days all operating characteristics were effectively the same as with typical starting conditions and therefore they expected the 30 day simulations would give the same result no matter what the initial conditions were. I don't think they are hiding anything here.