For the secondary and primary neutron source rods, the important internal pressure problem and the safety performance requirements are described respectively.

对于次级和初级中子源棒，分别阐述了重要的内压问题和有关的安全性能要求。

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The device's primary source of neutron radiation was the radioactive element californium, but the stream of neutrons produced by the californium was multiplied by passing it through a lattice of highly enriched uranium U-235, whose nuclear fission released additional neutrons.

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