- The thermal neutron absorption cross section of 135Xe is
2.75 x 106 barns.
- Like other fission products it is formed directly in fission and
also via other members of its isobaric chain.
- The half life of 135Te is short and effectively 135I
may be considered the primary fission product.
- Direct production of xenon is small compared to production by decay
of the iodine.
- For a period after such a fast shutdown in a high reactor there can
be an uncomfortable situation that the reactor cannot be started
again; there is not enough excess reactivity built into the system to
overcome the large neutron absorption effect from the 135Xe.