Benchmark k_eff Calculations of Critical Experiments of Borated, Highly Enriched Uranyl Nitrate Solutions

Conference · Sun Jun 02 04:00:00 EDT 1991 · Transactions of the American Nuclear Society

OSTI ID:5871977

Tanner, J. E. ^[1]

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1. Westinghouse Idaho Nuclear Co., Idaho Falls, ID (United States)

The k_eff values have been calculated for critical experiments on a highly enriched, concentrated uranyl-nitrate solutions, poisoned with varying amounts of boron and partly reflected with borated water and/or nickel. The experiments were performed at Los Alamos National Laboratory (LANL) in 1985. Sensitivities of the calculational biases to the solution composition, reflector type, and vessel dimensions are analyzed with KENO IV, KENO V.a-PC, and especially with DOT 4.3. The uranyl-nitrate solution initially contained 279 g {sup 235}U/{ell} (93.05%), which was diluted slightly on addition of the boric acid. The boric acid apparently contained water at an {approximately}1:1 molar ratio. Critical solution heights and boron concentrations are presented. It is apparent that the presence and nature of the reflector, which is only on the sides, has only a small effect. At low boron concentrations, the sides are only a small part of the total surface, and at high boron concentration, neutron losses are mostly due to absorption rather than escape. Qualitatively, the reflector effects are consistent from one solution composition to the next. The calculated k_eff values agree well among the three codes but show a systematic increase with increasing boron concentration, which also coincides with increasing solution height.

• Research Organization: Westinghouse Idaho Nuclear Co., Idaho Falls, ID (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP)
• OSTI ID: 5871977
• Report Number(s): CONF-910603--
• Conference Information: Journal Name: Transactions of the American Nuclear Society Journal Volume: 63
• Country of Publication: United States
• Language: English

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11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
42 ENGINEERING
420203* -- Engineering-- Handling Equipment & Procedures
97 MATHEMATICS AND COMPUTING
ACTINIDE COMPOUNDS
ACTINIDE ISO
ACTINIDE NUCLEI
ACTINIDES
ALPHA DECAY RADIOISOTOPES
AQUEOUS SOLUTIONS
BENCHMARKS
BORON
CALCULATION METHODS
COMPUTER CODES
CONTAINERS
CRITICALITY
CYLINDERS
DISPERSIONS
ELEMENTS
ENRICHED URANIUM
EVEN-ODD NUCLEI
HEAVY NUCLEI
HIGHLY ENRICHED URANIUM
HYDROGEN COMPOUNDS
INTERNAL CONVERSION RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPE ENRICHED MATERIALS
ISOTOPES
K CODES
K-Effective
KENO
LANL
MATERIALS
METALS
MINUTES LIVING RADIOISOTOPES
MIXTURES
MULTIPLICATION FACTORS
NATIONAL ORGANIZATIONS
NEUTRON REFLECTORS
NICKEL
NITRATES
NITROGEN COMPOUNDS
NUCLEI
Nuclear Criticality Safety Program (NCSP)
OXYGEN COMPOUNDS
RADIOISOTOPES
SEMIMETALS
SENSITIVITY
SOLUTIONS
SPONTANEOUS FISSION RADIOISOTOPES
TRANSITION ELEMENTS
URANIUM
URANIUM 235
URANIUM COMPOUNDS
URANIUM ISOTOPES
URANIUM NITRATES
US DOE
US ORGANIZATIONS
WATER