The brush thickens, then opens up to the bank of a muddy stream beside an abandoned factory in northwest Moscow. The crackling of the detector leads the two-man patrol to a hole where, at some point in Russia's less-than-careful nuclear past, radioactive material was dumped.

"People are usually joyful when they see us, to know that this control is going on so they can live safely," says Mr. Katzenbogen, who works for Radon, the government's radiation-control arm.

Two weeks ago, a Radon patrol seized more than 50 pounds of contaminated berries from a market - a common occurrence. In Moscow alone in the past five years, Radon has disposed of some 450 tons of potentially dangerous material - from soil at construction sites to market mushrooms - as limits on acceptable levels of radioactive contamination have steadily strengthened.

But while the patrols demonstrate a measure of success in Russia's efforts to clean up its nuclear act, they are dwarfed by the magnitude of the problem resulting from past failures to safely manage spent nuclear fuel and radioactive waste. Which is why many people at home and abroad are skeptical of a government plan - awaiting President Vladimir Putin's signature - to import 20,000 tons of nuclear waste over 10 years, earning a projected $21 billion.

"I don't think you'll find any place else in the world where spent nuclear fuel is stored in such bad conditions," says Thomas Nilsen, who studies Russia for the Norwegian environmental group Bellona, in Oslo. "The first priority should be to secure spent nuclear fuel and radioactive waste already existing in Russia. You don't do that by importing more."

Moscow's nuclear track record includes the 1986 Chernobyl disaster and last year's sinking of the Kursk submarine, with two nuclear-powered engines on board. Decades of improper storage of nuclear waste have left environmental devastation from Murmansk across Siberia to the Kamchatka Peninsula nine time zones away.

Russia's Ministry of Atomic Energy, or Minatom, is pushing the waste-import plan as a means of rescuing the industry. Proceeds also are meant to be used for a cleanup of waste sites, and may avert a disaster for the "100 old nuclear submarines" that are "becoming rusty and that one beautiful morning might just sink," says Minatom spokesman Vitaly Nasonov.

Current nuclear-waste storage facilities are virtually full, however, the only working processing plant is nearly a quarter-century old, and after decades of neglect, transport infrastructure - by which radioactive material would be moved - is collapsing.

"It's a calculated risk," says John Reppert, head of the Belfer Center for Science and International Affairs at Harvard University's Kennedy School of Government in Cambridge, Mass. "It is something they are clearly technically able to handle," he says. "But it is not something they have traditionally handled well or they wouldn't have that mess to clean up." And while Russia's vast unused spaces mean a wide margin for error, Mr. Reppert adds: "If they are going to create the world's largest and least-safe nuclear-waste dump, then it will be a long-term consequence for the rest of the world."

Critics, such as Bellona's Mr. Nilsen, also are concerned that the money will be misspent. "We are suspicious that most of the income from spent nuclear fuel will end up inside Moscow's ring road, and not in Siberia where the money is needed for environmental clean-up," he says.

There is one encouraging example. Reppert says that Russian experts have adhered strictly to tough fiscal and radiological standards when using official American funds - some of which he helped account for - to deal with weapons-grade nuclear material. The US is spending $874 million on such nonproliferation projects this year, though not all are deemed so successful. President Bush's 2002 budget slashes this spending by 10 percent.

The key to the large, new program is likely to be transparency, says Reppert. But unlike the built-in oversight tied to US donations, there may be few checks on how new funds are used.

Already, the plans are taking an unusual political path. The measure was due before the Federation Council, Russia's upper house, on Friday. But two days earlier, council chairman Yegor Stroyev quietly signed off on the plan, sending it directly to the president.

The plan is far from popular. A poll commissioned by the environmental group Greenpeace - echoed by other surveys - found that nearly 80 percent of Russians want Mr. Putin to block nuclear imports.

Yuri Schekochikhin, an opposition lawmaker in the Duma, or lower house, says he has seen the contents of one Berents Sea nuclear-waste facility washing out from a cracked concrete housing. The spillover, he says, sent a Geiger counter "off the scale."

"Russia is not ready to handle this dangerous cargo," he says.

Russia's scientific community appears divided. "Mass imports of spent nuclear fuel mean unavoidable catastrophic consequences for the ecology that will threaten the lives of Russia for centuries to come," nine members of the Russian Academy of Sciences warned in an open letter last month. Another letter - signed by three Nobel prize-winning Russian scientists - urged Putin to approve the bill, saying: "Nuclear fuel is not waste," will create jobs, and prove a future energy boon.

The example of Moscow's radiation-control teams should be taken into account, says Radon first deputy director Vladimir Safronov. Teams still find vials of highly radioactive radium paint - once used for luminescent clock faces, instrument dials, and even fishing lures. Rules first imposed in the 1960s and '70s, have only grown tougher. In 1998, acceptable contamination levels for food were slashed by a factor of 10. Eight tons of produce were destroyed that year. Mr. Safronov is "absolutely sure" that there are enough nuclear specialists to ensure the safety of the waste-import plan, but he is concerned that few young scientists are training for the future.

Radiation specialist Katzenbogen is not convinced. "Our generation will bring this material into the country, the next will process it, and the third will pay for all the mistakes," he says. "Everyone was sure that Chernobyl could never happen, and it did."

See also:

YABLOKO for Nuclear Safety

Christian Science Monitor, 3 July 2001