* Proposal would push requests closer to plant retirement
* Nine of 13 pending license reviews could be affected
HOUSTON, Sept 26 (Reuters) - Applications to relicense aging U.S. nuclear reactors would be delayed until the power plants are closer to retirement age and safety conditions are better known, under legislation introduced on Wednesday by two U.S. congressmen.
U.S. Representatives John Tierney and Edward Markey, both Massachusetts Democrats, said their proposal - the Nuclear Reactor Safety First Act - would provide "greater certainty" over the safety of older nuclear plants, according to a release.
The proposal would prevent the U.S. Nuclear Regulatory Commission (NRC) from granting a renewal of a nuclear facility operating license to a plant that applies more than 10 years before the current license is set to expire.
Of the 13 reactors currently seeking license extensions at the NRC, nine have licenses that do not expire for more than a decade.
The proposed legislation, if adopted, would have little immediate impact as the NRC has suspended issuing final decisions to renew licenses or grant new reactor licenses while it decides how to move forward with the controversial question of spent nuclear fuel, a delay some industry sources expect to last at least two years.
U.S. reactors were licensed to operate for 40 years and are allowed to apply to the NRC for a 20-year license extension.
Tierney and Markey cited problems at NextEra Energy Inc's 22-year-old Seabrook nuclear plant in New Hampshire as an example of a plant where problems with concrete degradation were identified during the license renewal process.
Seabrook's license won't expire until March 2030.
In May, the NRC sent a letter to NextEra confirming the company's plan to address the concrete degradation problem at Seabrook.
"It seems crazy that the NRC would even consider relicensing aging nuclear plants more than a decade before its license expires," said Tierney in the release. "As these facilities age, safety concerns inevitably arise."
The bill would ensure that licensees are evaluated for renewal within a reasonable time frame and not 20 years before a license expires, Tierney said.
The NRC's relicensing review process usually takes about three years but can take longer when public hearings are held. The longest relicensing review took six years.
A spokesman for NextEra said the current 20-year time frame for filing license renewal applications is appropriate.
"This time frame provides certainty for companies like ours to make major investments in plant upgrades and improvements that benefit the long-term health and safety of the plant," said Michael Waldron of NextEra.
Markey, a nuclear industry critic, said the legislation would ensure that "the effects of aging on America's nuclear power plants are more well-known before granting any license extensions."
"Allowing the NRC to give a 60-year-long clean bill of health to reactors that are in their nuclear adolescence, especially one with documented safety issues such as Seabrook, is like allowing a doctor to assure a 20-year-old smoker they will never get lung cancer," said Markey.
The nuclear industry's trade group said the proposal would unnecessarily constrain nuclear owners' plans to provide affordable power without enhancing safety.
"Operating nuclear power plants in the U.S. are kept safe regardless of their age," said Tony Pietrangelo, senior vice president of the Nuclear Energy Institute in Washington DC. "Nuclear plants must continuously meet strict safety standards, no matter how long they have been operating."
The NRC has approved license extensions for 73 of the nation's 104 reactors. No relicensing requests have been denied.
The NRC is currently reviewing licenses extensions for reactors operated by Exelon, Entergy Corp, Duke Energy, PG&E Corp, FirstEnergy and others. For a factbox on pending relicensing requests, see