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Regulations are loosened, and reactors are back in compliance."That's what they say for everything ...," said Demetrios Basdekas, a retired NRC engineer. "Every time you turn around, they say, 'We have all this built-in conservatism.' "The crisis at the decades-old Fukushima Dai-ichi nuclear facility in Japan has focused attention on nuclear safety and prompted the NRC to look at U.S. reactors. A report is due in July.But the factor of aging goes far beyond issues posed by Fukushima.

Commercial nuclear reactors in the United States were designed and licensed for 40 years. When the first were built in the 1960s and 1970s, it was expected that they would be replaced with improved models long before their licenses expired.That never happened. The 1979 accident at Three Mile Island, massive cost overruns, crushing debt and high interest rates halted new construction in the 1980s.Instead, 66 of the 104 operating units have been relicensed for 20 more years. Renewal applications are under review for 16 other reactors.As of today, 82 reactors are more than 25 years old.The AP found proof that aging reactors have been allowed to run less safely to prolong operations.

Last year, the NRC weakened the safety margin for acceptable radiation damage to reactor vessels -- for a second time. The standard is based on a reactor vessel's "reference temperature," which predicts when it will become dangerously brittle and vulnerable to failure. Through the years, many plants have violated or come close to violating the standard.As a result, the minimum standard was relaxed first by raising the reference temperature 50 percent, and then 78 percent above the original -- even though a broken vessel could spill radioactive contents."We've seen the pattern," said nuclear safety scientist Dana Powers, who works for Sandia National Laboratories and also sits on an NRC advisory committee. "They're ... trying to get more and more out of these plants."

Sharpening the pencilThe AP study collected and analyzed government and industry documents -- some never-before released -- of both reactor types: pressurized water units that keep radioactivity confined to the reactor building and the less common boiling water types like those at Fukushima, which send radioactive water away from the reactor to drive electricity-generating turbines.The Energy Northwest Columbia Generating Station north of Richland is a boiling water design that's a newer generation than the Fukushima plants.Tens of thousands of pages of studies, test results, inspection reports and policy statements filed during four decades were reviewed. Interviews were conducted with scores of managers, regulators, engineers, scientists, whistleblowers, activists and residents living near the reactors at 65 sites, mostly in the East and Midwest.

AP reporters toured some of the oldest reactors -- Oyster Creek, N.J., near the Atlantic coast 50 miles east of Philadelphia and two at Indian Point, 25 miles north of New York City on the Hudson River.Called "Oyster Creak" by some critics, this boiling water reactor began running in 1969 and is the country's oldest operating commercial nuclear power plant. Its license was extended in 2009 until 2029, though utility officials announced in December they will shut the reactor 10 years earlier rather than build state-ordered cooling towers. Applications to extend the lives of pressurized water units 2 and 3 at Indian Point, each more than 36 years old, are under NRC review.Unprompted, several nuclear engineers and former regulators used nearly identical terminology to describe how industry and government research has frequently justified loosening safety standards. They call it "sharpening the pencil" or "pencil engineering" -- fudging calculations and assumptions to keep aging plants in compliance.

Cracked tubing: The industry has long known of cracking in steel alloy tubing used in the steam generators of pressurized water reactors. Ruptures have been common in these tubes containing radioactive coolant; in 1993 alone, there were seven. As many as 18 reactors still run on old generators.Problems can arise even in a newer metal alloy, according to a report of a 2008 industry-government workshop.

Neil Wilmshurst, director of plant technology for the industry's Electric Power Research Institute, acknowledged the industry and NRC often collaborate on research that supports rule changes. But he maintained there's "no kind of misplaced alliance ... to get the right answer."Yet agency staff, plant operators and consultants paint a different picture:* The AP reviewed 226 preliminary notifications -- alerts on emerging safety problems -- NRC has issued since 2005. Wear and tear in the form of clogged lines, cracked parts, leaky seals, rust and other deterioration contributed to at least 26 of the alerts. Other notifications lack detail, but aging was a probable factor in 113 more, or 62 percent in all. For example, the 39-year-old Palisades reactor in Michigan shut Jan. 22 when an electrical cable failed, a fuse blew and a valve stuck shut, expelling steam with low levels of radioactive tritium into the outside air. And a 1-inch crack in a valve weld aborted a restart in February at the LaSalle site west of Chicago.

* A 2008 NRC report blamed 70 percent of potentially serious safety problems on "degraded conditions" such as cracked nozzles, loose paint, electrical problems or offline cooling components.* Confronted with worn parts, the industry has repeatedly requested -- and regulators often have allowed -- inspections and repairs to be delayed for months until scheduled refueling outages. Again and again, problems worsened before being fixed. Postponed inspections inside a steam generator at Indian Point allowed tubing to burst, leading to a radioactive release in 2000. Two years later, cracking grew so bad in nozzles on the reactor vessel at the Davis-Besse plant near Toledo, Ohio, that it came within two months of a possible breach, an NRC report said, which could release radiation. Yet inspections failed to catch the same problem on the replacement vessel head until more nozzles were found to be cracked last year.

Time crumbles thingsNuclear plants are fundamentally no more immune to aging than our cars or homes: Metals grow weak and rusty, concrete crumbles, paint peels, crud accumulates. Big components like 17-story-tall concrete containment buildings or 800-ton reactor vessels are all but impossible to replace. Smaller parts and systems can be swapped but still pose risks as a result of weak maintenance and lax regulation or hard-to-predict failures.Even mundane deterioration can carry harsh consequences.For example, peeling paint and debris can be swept toward pumps that circulate cooling water in a reactor accident. A properly functioning containment building is needed to create air pressure that helps clear those pumps. But a containment building could fail in a severe accident. Yet the NRC has allowed safety calculations that assume the buildings will hold.

In a 2009 letter, Mario V. Bonaca, then-chairman of the NRC's Advisory Committee on Reactor Safeguards, warned that this approach represents "a decrease in the safety margin" and makes a fuel-melting accident more likely.Many photos in NRC archives -- some released in response to AP requests under the federal Freedom of Information Act -- show rust accumulated in a thick crust or paint peeling in long sheets on untended equipment.Four areas stand out:

Brittle vessels: For years, operators have rearranged fuel rods to limit gradual radiation damage to the steel vessels protecting the core and keep them strong enough to meet safety standards.But even with last year's weakening of the safety margins, engineers and metal scientists say some plants may be forced to close over these concerns before their licenses run out -- unless, of course, new regulatory compromises are made.

Leaky valves: Operators have repeatedly violated leakage standards for valves designed to bottle up radioactive steam in an earthquake or other accident at boiling water reactors.Many plants have found they could not adhere to the general standard allowing main steam isolation valves to leak at a rate of no more than 11.5 cubic feet per hour. In 1999, the NRC decided to allow individual plants to seek amendments of up to 200 cubic feet per hour for all four steam valves combined.But plants have violated even those higher limits. For example, in 2007, Hatch Unit 2, in Baxley, Ga., reported combined leakage of 574 cubic feet per hour.

"Many utilities are doing that sort of thing," said engineer Richard T. Lahey Jr., who used to design nuclear safety systems for General Electric Co., which makes boiling water reactors. "I think we need nuclear power, but we can't compromise on safety. I think the vulnerability is on these older plants."Added Paul Blanch, an engineer who left the industry over safety issues, but later returned to work on solving them: "It's a philosophical position that (federal regulators) take that's driven by the industry and by the economics: What do we need to do to let those plants continue to operate?"Publicly, industry and government say that aging is well under control. "I see an effort on the part of this agency to always make sure that we're doing the right things for safety. I'm not sure that I see a pattern of staff simply doing things because there's an interest to reduce requirements -- that's certainly not the case," NRC chairman Gregory Jaczko said in an interview.

Corroded piping: Nuclear operators have failed to stop an epidemic of leaks in pipes and other underground equipment in damp settings. Nuclear sites have suffered more than 400 accidental radioactive leaks, the activist Union of Concerned Scientists reported in September.Plant operators have been drilling monitoring wells and patching buried piping and other equipment for several years to control an escalating outbreak.But there have been failures. Between 2000 and 2009, the annual number of leaks from underground piping shot up fivefold, according to an internal industry document.

That's small consolation to one prominent nuclear watchdog, who says it's not what's above ground that gives him the greatest concern. "Central to the issue is miles of buried pipe under the plant that carry radioactive water," says Paul Gunter, director of a nonprofit group called Beyond Nuclear.

unter cites recent problems with underground pipes at nuclear plants in Illinois and Vermont, where millions of gallons of water contaminated with the radioactive hydrogen isotope tritium seeped into groundwater, even as the power companies that owned the plants denied for years that it was happening.

The result of those leaks and their public concealment by the Exelon and Intergy power companies– at the Braidwood Station plant in Illionis and at the Vermont Yankee Nuclear Power Plant– was not additional government oversight as one might expect, says Gunter, but merely the creation of two voluntary programs that allow the power companies to inspect their own pipes and groundwater and then report the findings to the Commission.

Here's an industry that has hidden these leaks that is now self-reporting and overseeing itself to the NRC," says a disgusted Gunter.

at North Anna, newly arrived government inspectors won't be conducting their own tests of the miles of underground pipes. And the assumption that those pipes didn't sustain damage during the earthquake, which knocked two Louisa County schools out of commission and caused cracks in the Washington Monument some 90 miles away, might be laughable to Gunter if he weren't convinced of potentially grave public danger.

How can an uninspectable, inaccessible buried pipe have integrity?" Gunter asks. "When this Augmented Inspection Team walks onto the site, they'll be walking over the buried pipe that could be leaking." "We have a limited number of inspector resources," acknowledges Commission spokesperson Roger Hannah, who says when it comes to the pipes, inspectors will "make sure we see what [Dominion is] doing."

Hannah scoffs at the notion that tritium, already considered by the Commission a much lesser danger than uranium, could leak from damaged pipes into the groundwater and go unnoticed by inspectors. "If you had some issue, you'd see some leakage fairly quickly," says Hannah, noting that no tests have revealed radioactive leakage anywhere at the North Anna.

Dominion spokesperson Richard Zuercher also offers reassurance that all is well at North Anna, above and under-ground. "We do have ways to detect if there's any leakage in water," says Zuercher, who says the only damage at the facility was "cosmetic" and didn't affect nuclear function and who insists Dominion will "do whatever is necessary to verify that everything is intact." Gunter, however, says he believes Dominion's not going far enough to protect the public."Given the industry history and what's been done before, Dominion should be distributing bottled water to the town of Mineral and to the residents of Lake Anna," he says. "Indefinitely."

Fukushima local government can not let citizens leak out of the boarder because they lose their tax income. Thus they try to keep the citizens remaining in the area to keep paying tax.

Yamashita Shunichi rejected to conduct blood test and urine test for Fukushima children , he decided to do only echo screening test though it does never work until the children actually have tumor ,which is likely in 4~5 years from now.

The new policy was revealed during the meeting of experts affiliated with the Ministry of the Environment on August 27. So far, the Ministry's policy has been to allow the ashes with 8,000 becquerels/kg of radioactive cesium and below to be buried, but require the ashes that exceed that level to be stored temporarily while the Ministry decides on the disposal method.

Under the new policy, if radioactive cesium in the ashes exceeds 8,000 becquerels/kg but does not exceed 100,000 becquerels/kg, the ashes are allowed to be buried after they are bound with cement or put in a concrete container. If radioactive cesium exceeds 100,000 becquerels, then the ashes should be buried in the disposal facilities with a roof and/or with the concrete shield.

Radioactive cesium exceeding 8,000 becquerels/kg has been detected from the ashes from burning the regular household garbage in Kanto and Tohoku regions. The Ministry of the Environment has decided to apply the same rule as the disaster debris and allow the ashes to be buried. The municipalities will be able to bury the ashes that they have stored temporarily, but it may be difficult to obtain consent from the residents living near the disposal facilities.

The number "100,000 becquerels/kg" is significant in a sense, as the highest level of radioactive cesium found from ashes after burning the household garbage is 95,300 becquerels/kg in Fukushima Prefecture (link in Japanese). The number is high enough to clear the Fukushima garbage ashes, and it is probably high enough to clear garbage ashes from anywhere else.

Besides, as the NHK article states, even if it exceeds 100,000 becquerels/kg, all they need to do is to bury it in a disposal site with a roof or the concrete shield. This new policy is to be applied to ashes from disaster debris and regular garbage that are radioactive. It's not mentioned in the article but the ashes and slag from the radioactive sewage sludge will be likely to be disposed under the same policy - i.e. burn and bury. (And remember the "mix and match" scheme.)

In the meantime, some garbage incinerators and sludge incinerators at waste processing plants and sewage treatment plants in cities in Kanto have become so radioactive that they have to be shut down. (More later.) The entire country is to become the nuclear waste disposal site, because of one wrecked nuclear power plant. Talk about socializing the cost.