RRFM 2009 Transactions - European Nuclear Society

1 2 3 4 5 6 7 8 9
A
B
C
D
E
F
G
H
Figure 1: Layout of the SAFARI-1 Reactor Core
2.1 The Calorimeter Experiment
A calorimeter basically consists of two main regions: a core that is surrounded by an
atmosphere of air and a leak tight jacket. This is required to keep thermal insulation and
ensure isolation of the experimental sample from the surrounding. Thermocouples are
embedded in the core and jacket regions to measure the temperature difference through
signals sent to the monitoring device. Two cases are considered in this work: molybdenum
core and a stainless steel core calorimeter. For the purpose of this work, a calorimeter was
manufactured to the dimensions and specifications in Table 1.
Region Material Diameter (cm) Height (cm)
Core Molybdenum or SS* 304 1.143 4
Jacket SS* 304
* Stainless Steel
1.2 (inner)
1.3 (outer)
Table 1: Dimensions and Specifications of the Calorimeter
6
The MCNP5 model of the calorimeter is presented in Figure 2. The model is simplified to
exclude modelling of the thermocouples and other instrumentation coupled to the device, on
the assumption that these instruments will not affect the neutronic calculations in terms of
perturbing the neutron and photon flux spectrum in the channel hence also causing
perturbations on the heat calculations.
400 of 455