NUREG-1537, Part 2 - NRC

APPENDIX 18 I
The materials of any proposed modifications are compatible with use in the
reactor pool so that degradation should not be significantly faster or
different in ldnd than for the structure in use with the HEU core.
(7he reviewer also should discuss the analysis of the expected radioactiWty, that
will be induce4 and Uspossible effect on maintenance or operationsprocedures
in Section 12 and ultimate decommissioning in Section 15.3 of this appendix)
4.5. Dynamic Design
Areas of Review (Sections 4.5.1-4.5.4)
In reviewing the dynamic design of the proposed LEU-fueled reactor core, the
reviewer should analyze and compare the fuel system, control systems, and reactor
core physics parameters of the LEU-fiteled reactor with the existing BEU-fueled
reactor. These characteristics should be used to confirm that the integrity of the
proposed LEU-fuel will not be compromised and that the fuel design limits will not
be exceeded during operation or during postulated accident scenarios that are
discussed and analyzed in Section 13 of the SAR.
The dynamic design areas of review primarily cover normal reactor operation,
which is defined as operating with all process variables and other reactor
parameters within allowed conditions of the license, technical specifications,
applicable regulatory limits and design requirements for the system. This includes
the following topics: reactor core design bases, functional design of reactivity
control systems, and thermal-hydraulic characteristics. Postulated accident
scenarios should be briefly reviewed, but the details, consequences, and safety
significance should be analyzed and evaluated in Section 13 of this SAR.
Changes should by reviewed against existing technical specifications and their
bases (e.g., reactivity change rates such as control rod speeds and experiment
insertions). Analyses for the LEU-fueled reactor should reflect that changes are
appropriate.
The reviewer should cover the nuclear design of the proposed LEU-fueled reactor
under all of its allowed operating conditions, which include pulsing for some
reactors. This includes deviations from nominal operating conditions under which
the specific equipment is expected to operate and function in the safety analyses.
Deviations should be described by the mechanistic analyses and may define the
limiting conditions of operation. Examples of deviations include coolant flow
transients caused by valve realignments, variable time delays in the response of
instruments and controls, reactivity changes from experiments or control rod
motion, and loss of normal electrical power. Additional guidance may be found in
Shibata et a]. (1984).
NURBG-1S37, PART 2 14 REV 0,2/96
NUREG-1537, PART 2 14 REV 0, 2/96