THE ZEBRA FAST CRITICAL EXPERIMENTS AND BENCHMARKS

Fast reactor neutronics experiments are described and specified as benchmarks. The benchmarks are relevant to both sodium cooled and gas cooled fast reactor design studies. MCNP models are also provided for these benchmarks. The experiments were performed in the Zebra facility at Winfrith in the UK. Two programmes of experiments are described in detail, the Mozart programme (in support of the design of the Japanese fast reactor, MONJU) and the Cadenza programme of measurements in plate and pin geometry, and both with and without sodium, designed to provide basic reactor physics information. The descriptions of the benchmark models have been revised (February 2010) to improve aspects of the representation. Simplified models have also been re-evaluated.

Compiled by John L Rowlands - rowlandsjl[AT]aol.com

  1. Description of the ZEBRA Zero Energy Fast Critical Facility.

  2. The ZEBRA Experimental Programme.

  3. The Benchmarks:

Note: the documents specifying the benchmarks are large – up to 4Mb – and might take a couple of minutes to download. They are provided in both pdf and WORD2007 docx form. A docx reader is available from Microsoft for those who do not have WORD2007. Alternatively, OpenOffice Write

    1. The Zebra Cadenza Programme .
      ZEBRA-LMFR-EXP-001 Revision 1 (February 2010)
      A series of four simple geometry plutonium fuelled assemblies, with natural uranium blankets, comparing measurements in plate geometry and pin geometry form and in cores containing sodium and voided of sodium. The measurements are relevant to studies of sodium cooled and gas cooled fast reactors, to sodium voiding effects and methods for calculating cell heterogeneity. Criticality, spectral index and material reactivity worth measurements are included with particular attention to the differences in reactivity of the four assemblies.

Summary note
Benchmark document in pdf format (8,662 kb)
Benchmark document in docx format (3,770 kb) - Right-click and choose "save file..."

    1. The Zebra Mozart Programme Part 1 , MZA and MZB.
      ZEBRA-LMFR-EXP-002 Revision 1 (February 2010)
      The programme of measurements was in support of the design of the Japanese MONJU fast reactor. MZA had a simple single zone core whereas MZB had a two enrichment zone core of the size of MONJU. The extensive programme of measurements included criticality, spectrum and spectral indices, sodium voiding reactivity and material worth measurements and reaction rate distributions.

Summary note
Benchmark document in pdf format (8,963 kb)
Benchmark document in docx format (2,620 kb) - Right-click and choose "save file..."

    1. The Zebra Mozart Programme Part 2, MZC.
      ZEBRA-LMFR-EXP-003
      Studies of the reactivity effects of control rods, both individually and in arrays. The absorber material was boron at a range of enrichments, and tantalum, in rods of realistic geometry. Control rod followers were also simulated. Reaction rate distributions were measured both within rods and across the cores, with both symmetrical and asymmetrical arrays.

Summary note
Benchmark document in pdf format (2,428 kb)
Benchmark document in docx format (1,143 kb) - Right-click and choose "save file..."

  1. MCNP Models of ZEBRA CADENZA and MOZART Programme Fast Reactor Benchmarks.

      1. Description of the MCNP models.

MCNP-Models.pdf (500k)

      1. MCNP Input Decks

MCNP-Zebra.zip (660k)- Right-click and choose "save file..."