Sergei Ozhobishchev of the Center for the Problem of International Safety said that he feared the summit, scheduled to discuss nuclear safety worldwide, would be overtaken by political considerations.
Mr Ozhobishchev drew attention to two main concerns: that Russian President Boris Yeltsin will try to use the conference as a platform for his election campaign and that Western supporters of the Russian president will let him do so.
In the wake of the communist victory in the State Duma elections last December, the West has been keen to support Mr Yeltsin in any way it can.
Mr Ozhobishchev said at the Russia-American Press and Information Center that fears that nuclear safety in Russia may become a casualty of this attitude.
Mr Yeltsin is expected to use the summit to appeal for outside help to deal with Russia's failing domestic nuclear program.
Issues arising from last week's international conference in Vienna on the 10th anniversary of the Chernobyl disaster are expected to be high on the agenda.
The four-day Vienna conference was used by Russia, Ukraine and Belarus to make a plea for further international aid to help with health and social problems caused by the 1986 Chernobyl disaster.
There are 15 reactors of the Chernobyl type still in use throughout eastern Europe, including the reactor at Sosnovy Bor, 40 kilometers (25 miles) west of St Petersburg.
The Moscow summit will also discuss Russia's Kola peninsula in the northern Murmansk region. (SPP)