Ex-Soviet Nuclear Arsenal Feared Unsafe : Arms: As Russia and Ukraine bicker over maintenance, thoughts of another Chernobyl surface.

The safety of the former Soviet Union’s strategic nuclear arsenal has deteriorated in recent months as Russia and Ukraine quarrel over responsibility for its maintenance.

The dispute recently became public, revealing hazards that otherwise might have remained secret. But with each side playing up the dangers and blaming them on the other and minimizing its own faults, the threat of a nuclear accident is hard to assess.

Like an automobile that requires regular tuneups, nuclear weapons systems undergo periodic maintenance. Circuits are tested, machinery is lubricated, worn-out parts are replaced. Sometimes, everything works perfectly. Other times, the entire system needs overhaul.

In an article headlined “Another Chernobyl Is Growing in Ukraine’s Missile Silos,” the Russian newspaper Izvestia raised an alarm last month about conditions at intercontinental ballistic missile bases in Ukraine.

The report was based on interviews with Vladimir Nikityn, deputy commander of the Commonwealth of Independent States’ strategic rocket forces, and other Russian sources.

Izvestia reported that storage facilities in Ukraine were so overloaded with nuclear warheads that radiation levels outside them had risen to at least double the acceptable limits. It also said that leaky Ukrainian missile silos were in danger of short-circuiting “with unforeseen consequences” and that security systems at 20 weapons complexes were broken.

Marshal Yevgeny I. Shaposhnikov, Russian commander of Commonwealth forces, echoed some of the criticism in a separate statement last week, calling radiation from warheads in Ukraine “a threat to the health of military personnel” guarding them.

In an interview here Monday, Yuri Kostenko, Ukraine’s minister of environment, acknowledged that the nuclear weapons in his country are poorly maintained. But he blamed the situation on Russia, which a year ago suspended the servicing of missiles and warheads on Ukrainian territory. As a result, Kostenko said: “The situation is worse than it was six months ago. But it isn’t as dangerous” as the Russians portray it.

The Ukrainian minister, who is also chairman of a parliamentary commission on nuclear disarmament, insists that Russia faces the same safety problems that Ukraine does.

The finger-pointing reflects the struggle between Russia and Ukraine over control of 176 ICBMs inherited by Ukraine when the Soviet Union collapsed in 1991. Kostenko said Russia was withholding promised maintenance services at Ukrainian missile sites as a means of pressuring Ukraine to hand over the weapons.

Ukraine, in turn, is seeking economic aid and security assurances from Russia and Western nuclear powers before it will ratify the START I treaty on the reduction of nuclear weapons and rid itself of such weapons.

Even if Kiev ratifies the treaty, Ukraine and Russia will remain mutually dependent for the safety of nuclear arms on their territories in the seven years before the last of those on Ukrainian territory are to be destroyed.

The mammoth 10-warhead SS-18 missiles in Russia can only be maintained by the Ukrainian missile factory Pivdenmash that built them. Russia, in turn, services the 130 SS-19 missiles in Ukraine. More important, Russia holds the former Soviet Union’s monopoly on building, servicing and dismantling nuclear warheads, including the 1,240 in Ukraine.

That monopoly has resulted in egregious safety violations, Ukrainian officials assert. With thousands of nuclear weapons scheduled for retirement under recent disarmament treaties, the storage depots at Russia’s weapons dismantling facilities are bursting with nuclear warheads.

Kostenko said that Russia had refused for months to service the warheads in Ukraine, unless Kiev recognized them as Russian property. Although Kiev continued to insist that it owns the warheads, the two countries recently worked out a maintenance agreement.

Nevertheless, problems remain. For example, if Ukraine’s Pivdenmash factory needs to assemble a replacement part for Russia’s SS-18s, it must order components from dozens of factories in Russia, Belarus and other former Soviet republics. But to build the parts, those factories require widgets manufactured in Ukraine.

Kiev asserts that Russia’s suspension of maintenance services last year has disrupted the production chain and that some needed spare parts are no longer made. “It’s not that Ukraine doesn’t have the money for servicing the weapons,” Kostenko said. “There is nothing to buy.”