If you're a homeowner with standard insurance coverage, you're paying for protection against a range of possible dangers, including fire, windstorms, theft, various personal accidents and probably even dog bites.

But one risk your policy won't cover is the fallout from a nuclear accident.

The earthquake and tsunami that hit northern Japan, leaking contamination outside a nuclear plant, should have Arizonans thinking about their exposure in case a similar accident happened here.

The short answer is that standard homeowner's insurance policies don't cover nuclear dangers whether from a reactor accident, a problem involving waste storage or something else.

"In the event of a nuclear accident, like an act of war, the potential catastrophe is so large as to be almost unmeasurable," said Ron Williams, executive director of the Arizona Insurance Council. "It would be difficult to underwrite such a risk, so nuclear accidents are not covered in general homeowner policies."

But another type of insurance does offer at least some protection.

Nuclear-plant operators have been paying premiums into an industry fund under the Price-Anderson Act - federal legislation passed in 1957 to encourage the development of the nuclear-power industry by limiting liability and spreading out risk.

This fund now counts roughly $13 billion, reflecting premiums paid by nuclear-plant owners averaging about $400,000 annually for a single-unit reactor, according to the Nuclear Regulatory Commission.

The fund covers injury, deaths, property damage, living expenses for evacuated individuals and more.

All property- and liability-insurance policies issued in the U.S. exclude nuclear accidents, according to the commission.

The Price-Anderson fund was set in motion by the Three Mile Island nuclear accident, almost 32 years ago. The fund paid out more than $70 million in claims and legal costs tied to the accident. These included evacuation costs, lost wages, economic harm to businesses and the establishment of a local public-health fund.

Large U.S. and foreign companies, members of a consortium called American Nuclear Insurers, provide the coverage.

"It covers pretty much anyone who's affected - not just homeowners but renters and visitors, too," said Chris Kissell, senior managing editor at Insurance.com, an insurance-shopping and -information site that examined the nuclear issue.

He described the Price-Anderson nuclear fund as similar to federal deposit insurance, which is overseen by government regulators but funded by premiums paid by banks.

The analogy is fitting. Just as the deposit fund by itself probably couldn't contain multiple failures involving giant banks without Treasury help, $13 billion probably wouldn't be enough to handle a major nuclear calamity.

A 2009 study by professors Geoffrey Heal of Columbia University and Howard Kunreuther of the University of Pennsylvania estimated the direct and indirect costs of a major nuclear accident could run into the hundreds of billions of dollars. That assumes a significant radiation leak from a reactor near an urban center, such as the Indian Point power plant north of New York City, which the researchers cited.

In addition to wide-scale injuries, deaths and property damage, a bad accident, they contend, could lead to economic paralysis greater than that which followed the Sept. 11 attacks.

The insurance-industry fund would help but might not cover more than one-tenth of the total claims, requiring the federal government to fill the gap, according to the study. No wonder insurers aren't putting themselves on the hook for that sort of loss in homeowner's policies.

- Natural disasters bring out charitable inclinations in people, which in turn encourages scam artists.

Arizona Attorney General Tom Horne recently raised some of the customary cautions. If you wish to donate in support of the Japanese victims, make sure you're dealing with actual non-profit groups and be wary about giving out your credit-card number.

Call the Secretary of State's Office at 602-542-4285 or visit its website to verify that a charity is registered in Arizona under the business-filings area at www.azsos.gov.

Groups operating without registration are violating the law, but registration doesn't ensure that a charity's activities are legitimate or effective. Guidestar.org and charity navigator.org are two other sites that provide information on charities. You risk losing tax deductions if you make donations to entities that aren't qualified charities.

- While earthquakes aren't a big risk for Arizonans, let alone tsunamis, it's smart to check your insurance and emergency preparations when natural disasters are in the news.

Make sure you could locate important documents, family photos, valuables and other key items if you had to evacuate within a few hours. Consider where you would go, what you would do with pets and so forth. Make sure you can find insurance policies and know your financial-account passwords.

It's also smart to take a periodic inventory of your belongings. Photograph what you own and jot down model numbers, ages and approximate values of important items.

Reach Wiles at russ.wiles@arizonarepublic.com or 602-444-8616.