The chairman of a regulatory body has criticised his own agency’s policy on fire safety enforcement in nuclear plants.

Chairman of the Nuclear Regulatory Commission (NRC) in the US, Gregory Jaczko, branded “unacceptable” the agency’s continuing exercise of discretion in not enforcing fire safety provisions under NFPA-805, the standard for light water nuclear reactor plants.

The NRC’s vote last month to continue its policy of “enforcement discretion” would mean that most fire safety code violations at 44 of the country’s 101 nuclear reactors would not be enforced, according to the investigative website Pro Publica. It reports that many of the plants are relying on fire watches and other short-term measures, allowing companies to postpone installing fire suppression systems, barriers and other fire safety measures.

In a dissenting written statement accompanying the vote, Mr Jaczko said fire can still contribute significant risk to nuclear plants – as much as 50% of a the overall “core damage frequency”. Continued enforcement discretion, he said, would only delay the resolution of these issues by providing an incentive for plants to spend resources in other areas that do not address fire protection, and would prevent “lingering fire protection deficiencies” being identified.

“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,” said Mr Jaczko.

“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.”

But the industry’s trade body, the Nuclear Energy Institute, said the extended period of discretion was reasonable and that the policy did not extend to the most serious violations.

“If there is a significant safety issue at any of these plants, it would be addressed by the licensee and the regulator – period,” said Anthony Pietrangelo, the group’s chief nuclear officer.