3. DESCRIPTION
A vast program of fast reactor experiments was carried out at the Kernforschungszentrum Karlsruhe (KFK), now renamed Forschungszentrum Karlsruhe (FZK) over a long period that terminated at the end of the Eighties. The major research efforts were carried out at the Schnelle Null-Energie-Anordnung Karlsruhe (SNEAK), (i.e. Fast Zero-Power Facility Karlsruhe).
The construction of SNEAK started in 1965 and was completed in the summer of 1966. SNEAK is a vertical assembly, with the fuel elements attached to a carrying plate. Both vertical and horizontal channels can be built. The two horizontal channels serve for the material replacement experiments, achieved through an automatised sample changing device for measuring transverses with detectors or material samples and for a pulsed neutron source. The four vertical channels placed near the centre of the fissile region were designed for the installation of a pile oscillator. A circuit heated by gas served for Doppler experiments. The reactor was shut down in 1985.
For SNEAK, about 600 kg of plutonium were processed to mixed oxide (MOX) fuel pellets starting in 1965.
This effort was carried out in support of the German fast reactor programme that led to the construction of the KNK-II facility. The KNK Compact Sodium Cooled Nuclear Reactor Facility was a 20 MWe experimental nuclear power plant erected on the premises of Forschungszentrum Karlsruhe. This provided valuable information for the construction of the Kalkar fast breeder reactor, completed in 1991. This reactor was never loaded with fuel and the German fast reactor programme was later abandoned.
The wealth of information produced in the SNEAK Facility covers the following measurement campaigns in different core configurations:
Assembly (Year) Features
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1 1966/67
Task: check of assemblyand equipment
Special Features: mock-up of ZPR-3, Assembly 41
Main Constituents: 235U, 238U, Al, steel
3A 1967
Task: simulation of steam cooled FBR
Special Features: simulation of H2O by
polyethylene foils
Main Constituents: 235U, 238U, CH2, steel, Al,
Al2O3
3B 1968
Task: as 3A
Special Features: as 3A, central Pu-fuelled zone
Main Constituents: as 3A, in addition PuO2/UO2
4 1968/69
Task: mock-up of KNK-II
Main Constituents: PuO2, PuO2/UO2, 235U, 238U,
steel, Al
5 1969
Task: physics investigations: neutron balance
Special Features: central k8 = 1 zone
Main Constituents: k8-zone PuO2/UO2, 238U, C
driver 235U, 238U, C, Al, H
2A 1969
Task: simulation of a sodium-cooled FBR
Special Features: uranium core, 2 enrichment zones
Main Constituents: 235U, 238U, steel, Na, Na2CO3
2B 1969
Task: as 2A
Special Features: as 2A, sector Pu-fuelled
Main Constituents: as 2A, in addition PuO2/UO2,
Fe2O3
2C 1969
Task: as 2A
Special Features: as 2B, additional MASURCA-Pu
Main Constituents: as 2B,
Pu-metal in MASURCA-Pu-pins
6A 1970
Task: as 2A
Special Features: central zone PuO2/UO2,
additional MASURCA-Pu
Main Constituents: PuO2/UO2, 235U, 238U, steel,
Na, Al, Fe2O3, Pu-metal
6B 1970
Task: as 2A
Special Features: As 6A, but without MASURCA-Pu
Main Constituents: PuO2/UO2, 235U, 238U, steel,
Na, Al, Fe2O3
6D 1970
Task: as 2A
Special Features: central zone MASURCA-Pu,
additional SNEAK-PuO2/UO2
Main Constituents: as 6A
7A 1970/71
Task: basic physics
Special Features: 1-zone-core
Main Constituents: PuO2/UO2, graphite
7B 1971
Task: as 7A
Special Features: as 7A
Main Constituents: PuO2/UO2, UO2
8 1971
Task: k8 = 1 (SCHERZO)
Special Features: central k8 = 1 zone, as ZEBRA,
ERMINE, HARMONIE
Main Constituents: 235U, 238U, graphite in driver
9B 1972
Task: Mock-up of SNR 300
Special Features: large central zone,
composition of SNR 300
Main Constituents: PuO2/UO2, 235U, 238U, Na,
Na2CO3, graphite
9A 1972/73
Task: as 9B
Special Features: simulation of SNR geometry,
U-fuel, SNR control rods 9A-0 without control rods
9A-1 withdrawn control rods 9A-2 inserted control
rods
Main Constituents: 235U, 238U, Na, Na2CO3,
graphite
9C-1 1973/74
Task: as 9B, also basic physics
Special Features: 1-zone U core,
progressive Pu for U substitution
Main Constituents: 235U, 238U, steel, Na, Na2CO3,
graphite
9C-2 1974/75
Task: as 9C1
Special Features: 1-zone Pu core
Main Constituents: PuO2/UO2, Na
10 1975/76
Task: Simulation of properties of large FBRs
Special Features: compact core (no Na, low radial
leakage) different control rod patterns in 10A/B/C
Main Constituents: 235U, 238U, UO2, Al2O3,
graphite
11 1977/79
Task: Mock-up of KNK-II (incl. details)
Special Features: test region fuelled with
carbide, Mark IA, Mark II fuel (11A/B/C)
Main Constituents: PuO2/UO2, 235U, 238U, steel,
Na, PuO2, Na2CO3, CH2
12A 1980/82
Task: deformed cores
Special Features: 1-zone U core
Main Constituents: 235U, 238U, UO2, Na
12B 1983/84
Task: as 12A
Special Features: central zone fuelled with
PuO2/UO2 pin bundles
Main Constituents: PuO2/UO2 pins and plates, UO2,
235U, 238U, steel
12F 1984
Task: HCLWR studies
Special Features: central zone as 12B, moderated
with C8H8 plates, steel buffer
Main Constituents: PuO2/UO2 pins, C8H8, steel in
test zone, driver as 12B
12C 1984/85
Task: deformed cores and control rod studies
Special Features: as 12B, central zone loaded
with plates
Main Constituents: as 12B, without plates
The primary Documents have been assembled in this package within the IRPhE Project (International Reactor Physics Benchmark Experiments Project) of the OECD Nuclear Energy Agency.
The numerical values were compiled and assembled as one chapter in the SNEDAX database. These data have also been released to the project.
This information was released by staff of the FZR (E. Kiefhaber, G. Heusener, and R. Bohme) and is made available to inernational programmes through OECD/NEA.
