The Great Tohoku Earthquake and the resulting tsunamis and aftershocks may lead to life and health insurance claims with a value equivalent to about $3.7 billion to $5 billion.

Analysts at Moody’s Investors Service, New York, have published that estimate in a report on the effects of the series of disasters that struck Japan starting March 11.

“Life insurers with exposure to the region will be impacted by increased death claims, higher accident and health benefits, and lower revenues,” Moody’s says.

But, according to Moody’s, the insured value of the claims resulting from the disasters – 300 billion yen to 400 billion yen – should be manageable relative to the capital and, in most cases, the earnings capacity, of the life insurers operating in Japan.

As of March 25th, Japan’s National Police Agency has confirmed that 10,035 people died as a result of the disasters, and that 17,443 were unaccounted for. The disasters also left nearly 3,000 injured and some 240,000 people homeless.

Tens of thousands of survivors are reported to be living in shelters or other places with inadequate food, water, medicine and heat, and some survivors and others are reporting on Twitter that some of the survivors are suffering from influenza-like illnesses.

The earthquakes and tsunamis also have caused severe damage to at least one Japanese nuclear power plant. Despite initial reports that the Fukushima Dai-ichi nuclear power plant did not sustain damage to its core, in the days following the earthquake, the reactor did in fact begin to leak. As emergency teams scrambled to keep the reactor core from fully melting down, the question became not whether any radiation had been released into the surrounding environment, but how much. By March 28, radioactive contamination in water within the plant had registered at 100,000 times normal levels, prompting fears that the water could seep out into the Pacific Ocean. The constant threat of exposure to plant workers has further complicated efforts to address the compromised reactor, which leaves the Kukushima crisis an ongoing one.

“The situation in Japan remains uncertain and fluid,” Moody’s analysts say. “The wild card in all of this is the nuclear story which is unfolding. Should a severe meltdown occur and the effects be felt as far away as Tokyo for an extended period of time, the economic impact to life insurers in terms of adverse business and financial impact is much more material. Under the scenario of a severe radioactive release, it is our view that companies with a significant in-force of [accident and health] policies would incur meaningful losses right away, with life insurance claims occurring more gradually and escalating over the coming years.”

In Japan, “with very minor exceptions, policies do not contain nuclear, biological, or radiological exclusions,” the analysts say.

But, assuming Japan can avoid having radioactive material affect a large area of Japan for an extended period, the life and health companies that Moody’s rates in Japan should get through the disasters with their ratings largely intact, the analysts say.

Most of the companies are geographically well diversified, and few have large operations in the most heavily affected areas, the analysts say.

“Employees of the insurers for the most part are safe and working, although there have been some business disruptions,” the analysts say.

The Moody’s analysts are assuming that the total number of deaths in Japan will rise to about 20,000; that the average policy size in force will be the equivalent of about $200,000, including both the death benefit and an accidental death benefit rider; and that the average policy size is about the same at most private insurers.

If those assumptions are correct, life insurers in Japan could face the equivalent of about $2.5 billion in insured death claims and about $2 billion in accident, health and supplemental health claims, the analysts estimate.

The earthquakes and tsunamis also have caused short-term turmoil for insurers’ investment portfolios, but values should recover, and the insurers have ample liquidity, the analysts say.

Meanwhile, as radioactive particles from the stricken Fukushima power plant dispersed across the Pacific Ocean, concerns arose in the United States, particularly in Washington, Oregon and California, over the potential risk of radiation exposure. Authorities say the radiation leaked from the reactors will be far too weak once it reaches the United States to cause acute health problems. But news of the leaks has caused some Americans to ask about what their policies would cover if high radiation levels did affect the United States.

Amid such concerns, Phil Young, a life insurance policy analyst at Life Quotes Inc. in Darien, Ill, noted that a standard U.S. life insurance policy would indeed cover death from radiation poisoning.

Most U.S. automobile policies and homeowners policies exclude coverage for nuclear accidents, because American Nuclear Insurers, Glastonbury, Conn., runs a special program that provides a total of about $13 billion in protection against property-casualty damage caused by nuclear accidents.

But typical U.S. life policies contain no exclusions for nuclear accidents, Young says.

“The standard U.S. life insurance policy covers death by any cause at any time in any place, except for suicide within the first two policy years in most states or one year in some states,” Young says. “So, yes, death by direct radiation poisoning or death by an eventual cancer or other radiation complication would be covered by the typical comprehensive life insurance policy.”