A Nuclear Regulatory Commission investigation found no safety problems in the dry casks manufactured by Holtec, a company that makes equipment for storing high-level radioactive waste. A whistleblower alleged that defective welds and quality-assurance errors compromised the casks? ability to safely hold nuclear power plant waste for potentially thousands of years until a central repository is built (<i>Circuit<\/i>, September 5, 2003). The NRC concluded in a July 27 report that while there were deficiencies, they ?did not adversely impact the physical integrity of the Holtec dry cask storage systems.? The NRC inspector general?s report affects California because Holtec was chosen by Pacific Gas & Electric to build storage casks for on-site warehousing of plutonium and other high-level waste at both its Diablo Canyon and Humboldt Bay facilities. The NRC did not dismiss the allegations by former Exelon employee Oscar Shirani; instead, it verified the conditions he described in his complaints yet found them to be nonthreatening. ?The Office of Inspector General found no record that either NRC inspections or [industry] audit reports uncovered systemic, significant problems,? said the report. It concluded that there is ?no significant safety or regulatory issue that required further NRC action.?