The written comments by NRC Chairman Gregory B. Jaczko , released last week, were made as the commission voted in late May to continue a policy of citing only the most serious fire violations at 44 of the nation’s 101 reactors that are in the process of updating fire plans, and to address old hazards.
As ProPublica recently reported , many of the plants are relying on fire watches and other short-term measures while they work on their new plans. But critics say the NRC’s enforcement policy has allowed nuclear companies to put off installing fire suppression, barriers and other safety features for years.
Fire is among the most serious risks to nuclear reactors, according to NRC experts. Jaczko said in the written statement explaining his vote that fires can represent as much as 50 percent of a plant’s “core damage frequency ”—the likelihood of an accident that affected a reactor’s radioactive fuel.
Jaczko said that the NRC should have been better prepared to review the nuclear companies’ fire plans. Instead, he said the agency had let the process drag on too long.
“The bottom line is that licensees have had years to identify fire protection deficiencies, and the commission must close this very long chapter of not enforcing all fire protection violations,” he wrote.
“But the continued willingness to tie inspectors’ hands by limiting the tools they have available to ensure we meet our mission of protecting public health and safety, is more than disappointing—it is unacceptable.”
The NRC policy, called “enforcement discretion ,” started in 2004 as a way to encourage nuclear companies to submit to a new fire regulation that’s an alternative to the one-size-fits-all fire code.
Under the alternate regulation, companies can customize fire protection to better fit unique issues at their reactors. NRC hopes that plants enrolled in the program will have approved plans within the next several years.
The commission’s vote  was on whether to extend enforcement discretion for those plants while companies submit proposed fire plans for NRC review on a staggered schedule beginning June 29.
According to NRC records, there have been at least 154 fires at nuclear plants since 1995, an average of 10 a year. On June 7, a fire  at the Fort Calhoun nuclear plant in Nebraska temporarily knocked out cooling to a pool holding spent fuel at the site, prompting an emergency declaration.
In an interview, officials of the nuclear industry’s trade group, the Nuclear Energy Institute , said the extended period of enforcement grace was reasonable.
Anthony Pietrangelo, the group’s chief nuclear officer, said it would be counterproductive for the NRC to issue violations for things that the nuclear companies were working to fix.
Mr. Pietrangelo pointed out, as have Jaczko and other NRC officials, that enforcement discretion does not mean that serious hazards in the plants are ignored.
The enforcement discretion policy does not extend to the most serious violations, which the NRC defines as “red.” For less serious deficiencies, nuclear companies also must put in place interim measures, such as stationing a fire watch, that are reviewed by the NRC to ensure the plants are safe.
“If there is a significant safety issue at any of these plants, it would be addressed by the licensee and the regulator—period,” Pietrangelo said.
Jaczko, a former congressional staffer and physicist who President Obama named chairman in 2009, has previously said he opposed extending enforcement discretion , but his May remarks are the most extensive critique of the policy to date.