Chernobyl Nuclear Accident Congressional Hearings Transcript

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165
stantiated by a recent Associated Press report that Ivan
Emel'yanov, Deputy Director of the RBMK design organization,
"confirmed speculation that the reactor did not have a conventional
containment vessel used in the West to prevent
radiation leaks in case of a breakdown." The evidence does
appear to point toward newer RBMKs like Chernobyl-4 being
equipped with some compartmentalization and a pressure suppression
system called a 'bubbler pond'. Earlier RBMKs
appear to have no such pressure suppression capability.
But, as previously stated, even the more modern Soviet RBMK
structural designs would not qualify in the U.S. as "containment."
A more appropriate term would be "limited
pressure suppression capability."
We base this conclusion of lack of full containment on four
observations
• First, it appears that only part of the primary system
is enclosed within a boundary intended to be pressure
tight. Reactor inlet piping is enclosed, but Soviet
literature implies that reactor outlet piping and the
four large steam drums or steam separators are outside
the pressure suppression boundary enclosure. We doubt
that the reactor core itself is protected by a strong
pressure boundary. There is a sealed barrier around the
core that encloses the mixture of helium and nitrogen
that cools and protects the graphite from oxygen, but
the pressure and explosion-handling capability of this
region is doubtful.
• Second, the numerous piping penetrations of the various
pressure boundaries and biological shields do not appear
to be equipped with isolation capability (e.g., pressure
tube exit isolation valves, main steam isolation valves,
main feedwater isolation valves).
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