In the wake of World War II, Edward Teller, often called the "Father of the Bomb," presided over the development of sophisticated nuclear weapons that helped establish one of the enduring dogmas of the nuclear age - that atomic weapons are a cheap way to wage war and keep the peace.

By the late 1950s, Teller's Lawrence Livermore Laboratory had increased the "efficiency" of nuclear bombs to the point that a single one could kill 10 million people at a cost of only 12 cents for each death - vastly cheaper than conventional explosives.But 30 years after defense analysts spun this macabre bit of arithmetic, nuclear warfare's compelling economics are now on the brink of disintegrating. Beset by dangerous spills, obsolete facilities and shoddy management practices, the U.S. production complex for this key defense component is crumbling and unsafe.

The cost of fixing it, according to some analysts, could surpass $155 billion over the next 25 years, making maintenance of a nuclear arsenal suddenly a very costly proposition.

With the government saddled by a huge budget deficit, the new equation is already pushing U.S. policymakers to shift more emphasis to conventional weapons for the nation's defense, and creating added pressure for negotiating nuclear weapons reductions with the Soviet Union.

At the same time, officials acknowledge that there is no avoiding a thorough - and expensive - revamping of U.S. nuclear arms production. A nuclear missile force, regardless of future treaty initiatives, now unalterably is a part of being a global superpower.

The United States has 14 military nuclear facilities, managed by the Department of Energy, spread across the nation and occupying a land area larger than Delaware and Rhode Island combined. Many were built in the 1940s and 1950s and, though upgraded over the years, are now approaching the end of their useful life, experts say.

In recent months, problems in the aging complex have reached a head. The nation's sole nuclear reactor for producing tritium, a critical weapons ingredient, at Savannah River, S.C., was shut down in August. At the Hanford Reservation in Washington state, the Department of Energy closed the plutonium-producing reactor last February because of growing concern over the safety of its operations.

What is needed, federal and independent experts say, is a comprehensive program to phase out obsolete bomb factories, rebuild essential ones and, using new management and technology, bring a basic production complex up to safe and modern working standards.

But coming up with the money for such an endeavor so far has proven to be a daunting challenge.

Even if the $155 billion-plus cost estimated by the General Accounting Office was spread out evenly over the next 25 years, the annual cost would be $6.2 billion - or almost as much as the Department of Energy now spends for all nuclear weapons activities.