Reactivity effect of beryllium reflector poison in the ATR

Conference · Tue Jan 01 04:00:00 EST 1991 · Transactions of the American Nuclear Society; (United States)

OSTI ID:5980889

Smith, A C; Yoon, W Y; Auslander, D J ^[1]

---

1. Idaho National Engineering Lab., Idaho Falls (United States)

The Advanced Test Reactor (ATR) is a 250-MW uranium-aluminum-fueled materials test reactor located at the Idaho National Engineering Laboratory. Forty highly enriched uranium fuel elements are arranged in a serpentine configuration within the compact core resulting in a very high power density of (1.0 MW/{ell} of core). Materials to be tested are inserted into a number of experiment holes and in-pile-tubes. As a means of increasing the neutron flux in the A, B, H, and I holes in addition to the other test capsule and in-pile-tubes, a beryllium reflector is utilized. Exposure of the beryllium reflector during reactor operation necessarily results in the buildup of {sup 6}Li and {sup 3}He in the reflector. These two reaction products are characterized by their large thermal neutron absorption cross sections. As a result, a quantifiably large reactivity loss is experienced in the ATR. In an attempt to improve the predictive calculation of reactivity loss experienced in the ATR beryllium reflector, decay chains representing the two major activation product poisons ({sup 6}Li and {sup 3}He) have been incorporated into the PDQ7-II neutron diffusion theory calculational models.

• OSTI ID: 5980889
• Report Number(s): CONF-910603--
• Conference Information: Journal Name: Transactions of the American Nuclear Society; (United States) Journal Volume: 63
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210600* -- Power Reactors
Auxiliary
Mobile Package
& Transportable
ABSORPTION
ACTINIDES
ALKALI METAL ISOTOPES
ALKALINE EARTH METALS
ATR REACTOR
BARYONS
BERYLLIUM
COMPUTER CODES
COMPUTERIZED SIMULATION
DIFFERENTIAL EQUATIONS
DISPERSION NUCLEAR FUELS
ELEMENTARY PARTICLES
ELEMENTS
ENERGY SOURCES
ENRICHED URANIUM
ENRICHED URANIUM REACTORS
EQUATIONS
EVEN-ODD NUCLEI
FERMIONS
FUEL ELEMENTS
FUELS
H CODES
HADRONS
HELIUM 3
HELIUM ISOTOPES
HIGHLY ENRICHED URANIUM
IDAHO NATIONAL ENGINEERING LABORATORY
IRRADIATION REACTORS
ISOTOPE ENRICHED MATERIALS
ISOTOPES
LIGHT NUCLEI
LITHIUM 6
LITHIUM ISOTOPES
MATERIALS
MATERIALS TESTING
MATERIALS TESTING REACTORS
METALS
NATIONAL ORGANIZATIONS
NEUTRON DIFFUSION EQUATION
NEUTRON FLUX
NEUTRON REFLECTORS
NEUTRONS
NUCLEAR FUELS
NUCLEAR POISONS
NUCLEI
NUCLEONS
ODD-ODD NUCLEI
OPERATION
P CODES
PHYSICS
POWER DENSITY
RADIATION FLUX
REACTIVITY
REACTOR COMPONENTS
REACTOR CORES
REACTOR EXPERIMENTAL FACILITIES
REACTOR MATERIALS
REACTOR OPERATION
REACTOR PHYSICS
REACTOR SHUTDOWN
REACTORS
RESEARCH AND TEST REACTORS
SHUTDOWN
SIMULATION
SOLID FUELS
STABLE ISOTOPES
TANK TYPE REACTORS
TEST REACTORS
TESTING
THERMAL NEUTRONS
THERMAL REACTORS
URANIUM
US DOE
US ERDA
US ORGANIZATIONS
WATER COOLED REACTORS
WATER MODERATED REACTORS