Radiation Shielding Seals .
Determine the project criteria for the degree of radiation shielding
required at penetrations. Provide calculations to support the shielding
Select penetration sealant material based on satisfactory performance of
sealant in meeting project radiation shielding criteria, life expectancy of
sealant in radiation environment compatibility with adjacent materials, and
Consider external mechanical loads on penetrating element (pipe, etc.)
and differential movement between penetrating element and structure
that may cause the seal to fail or be dislodged.
General Jumper Design Considerations . Chemical processing vessels in
nonreactor nuclear facilities often are located in areas of high radiation with very
limited access capabilities. In order to transport process materials as well as the
services required for the process, pipes are fabricated with the capability of being
installed remotely by cranes. Such pipes are called jumpers. Jumper design
requires many special considerations in addition to normal needs, which are
discussed in this section.
Pipe jumpers are installed by remotely operated cranes between the
vessel nozzles and wall nozzles by means of connector blocks. The
installation is performed by using an impact wrench mounted on the crane
hook. Since the installation is performed by the operator at a remote
location, the tolerances are evaluated based on:
the ability to remotely lower the pipe into the connected nozzles
(i.e., tighter clearance tolerances make the installation process more