NUREG-1537, Part 2 - NRC

CHAPT 4
* The applicant has justified appropriate limiting conditions for operation and
surveillance requirements for the source and included them in the technical
specifications.
* The source and holder design operate safely and reliably.
4.2.5 Core Support Structure
Areas of ReWew
All reactor core components must be secured firmly and accurately because the
capability to maintain a controlled chain reaction depends on the relative positions
of the components. Controlling reactor operations safely and reliably depends on
the capability to locate components and reproduce responses of instrument and
control systems, including nuclear detectors and control rods Predictable fuel
integrity depends on stable and reproducible fuel components and coolant flow
patterns. Most fixed non-power reactor cores are supported from below. Some
are suspended from above, and may be movable. Generally, the control rods of
non-power reactors are suspended from a superstructure, which allows gravity to
rapidly change core reactivity to shut down the reactor.
Areas of review include the design of the core support structure, including a
demonstration that the design loads and forces are conservative compared with all
expected loads and hydraulic forces and that relative positions of components can
be maintained within tolerances
Additional areas of review are discussed in this section of the format and content
gulide.
Acceptance Criteria
Acceptance criteria for the information on the core support structure include the
following:
* The design should show that the core support structure will conservatively
hold the weight of all core-related components with and without the
buoyant forces of the water in the tank or pool.
* The design should show that the core support structure will conservatively
withstand all hydraulic forces from anticipated coolant flow with negligible
deflection or motion.
* The methods by which core components (individual fuel elements, reflector
pieces, control rods, experimental facilities, and coolant systems) are
NUREG- 1 537, PART 2 4-12 REV 0, 2/96