Republicans on the House Energy and Commerce Committee indicated yesterday that they plan to scrutinize the Nuclear Regulatory Commission's new post-Fukushima safety upgrades for U.S. reactors with the same zeal that they have homed in on U.S. EPA's clean air regulations.

"In the 112th Congress, this committee focused significant attention on the combined effect that many substantial EPA regulations have had on our nation's coal plants," Energy and Commerce Chairman Fred Upton (R-Mich.) and almost two dozen House Republicans told NRC Chairwoman Allison Macfarlane in a letter yesterday.

"As indicated in our July 24, 2012, hearing, we are similarly concerned about the potential cumulative impact of numerous post-Fukshima and other regulatory changes on our nation's nuclear plants," they wrote.

Lawmakers including Reps. Marsha Blackburn (R-Tenn.), Phil Gingrey (R-Ga.) and Ed Whitfield (R-Ky.), chairman of the Energy and Power Subcommittee, also signed the letter.

The lawmakers said NRC faces competing and conflicting viewpoints and insufficient data while implementing safety upgrades stemming from the 2011 nuclear disaster at Japan's Fukushima Daiichi plant.

NRC is beefing up security at U.S. plants after three Japanese reactors were crippled by an earthquake and tsunami in March 2011. Emergency diesel generators needed to keep the units cool were washed away, allowing hydrogen to build up and trigger explosions and radioactive leaks.

But the Republicans criticized NRC for taking a "piecemeal approach" and urged the agency to be careful not to burden plant operators with too many changes at once. The Nuclear Energy Institute is also calling on NRC not to overburden the industry and distract from the current operation of plants.

The GOP letter focused on the NRC staff's recommendation that almost a third of the U.S. nuclear fleet install filtering systems to prevent explosions during accidents.

The staff recommended in November that plants with Mark I and Mark II containment systems -- identical to the Japanese reactors that were crippled last year -- install systems to avoid the buildup of explosive hydrogen gas. The systems can cost up to $45 million each (Greenwire, Nov. 2, 2012).

At the time, John Monninger, deputy director of NRC's Division of Risk Analysis, said the equipment would allow operators to release steam and pressure from a damaged nuclear power plant while using filters to better protect the public and workers from radiation. Filtered vents are systems of water-filled tanks, sand or other materials that scrub the gas of radioactive material before it leaves the plant.

Anti-nuclear groups are fully backing the staff's recommendation, calling the decision a "no-brainer."

But Republicans said NRC overlooked an internal NRC panel's concerns about the cost estimates that staff used and called on the agency to take more time to analyze the proposal. "A piecemeal approach of deciding the filtered vent issue in isolation, while potentially eroding the adequate protection standard is in our opinion not appropriate," the lawmakers wrote.

The industry is also opposed to requiring filtered vents. Tony Pietrangelo, NEI's senior vice president and chief nuclear officer, has said U.S. operators follow detailed procedures during severe accidents that would direct them when to vent early, and installing new equipment won't prevent a radioactive release.

NRC staff met with industry officials and Pietrangelo today in Rockville, Md., and said the full five-member commission will ultimately decide whether plant operators must install filtered vents. It is also not clear how many plants will have to make changes to offset seismic or flooding risks.