On March 28, 2020, the United States Nuclear Regulatory Commission (NRC) released a letter stating that in the face of the COVID-19 pandemic, it is allowing power reactor operators to apply for temporary exemptions from regulations limiting the amount of hours workers can stay on the job.[1] Additionally, the NRC staff is working on a separate memorandum that will guide nuclear plants as to which labor and time-intensive tasks they can temporarily waive. During normal situations, the NRC has several rules about the maximum length of employee shifts and requirements for breaks workers must take between long shifts. However, the strains created by the COVID-19 pandemic have created a need to ensure that these regulations "do not unduly limit licensee flexibility in using personnel resources to most effectively manage the impacts" of the pandemic.
Nuclear reactors have already been enacting contingency plans designed to limit the number of workers onsite in order to avoid potential exposure to the coronavirus. It is unknown how long nuclear reactors will need operate with these reductions in staff and maintenance tasks, and whether they can stay running as often as they do in normal times, but the NRC measures to loosen restrictions are intended to ease the strain.
[1] https://adamswebsearch2.nrc.gov/webSearch2/main.jsp?AccessionNumber=ML20087P237