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Research Reactor

The Ohio State University Research Reactor (OSURR) is a pool‑type reactor, with multiple beam ports and dry tubes as irradiation facilities, that is utilized for a variety of instructional, research, and service activities. It is licensed to operate at thermal powers up to a maximum of 500 kilowatts, and at this maximum steady‑state power, the maximum thermal neutron flux in the central irradiation facility is approximately 1.4x1013 n/cm2/s.

A number of experimental facilities converge at the reactor core, which allows simultaneous performance of multiple experiments. These facilities include two beam ports, a pneumatic transfer facility, a graphite thermal column, a central irradiation facility that extends into a water‑filled flux trap, auxiliary and peripheral irradiation facilities, and movable dry tubes.  A summary table listing the neutron fluxes and dose rates in the various OSURR facilities can be found here.

The central irradiation facility (CIF) consists of a 1.3-inch inner-diameter tube that extends from the top of the reactor pool down into the central grid position of the core. This facility has the highest available flux at the OSURR, with a maximum total flux of 2.3x1013 n/cm2/s, and a maximum thermal flux of 1.4x1013 n/cm2/s.

The auxiliary irradiation facility (AIF) is a 2.45-inch inner-diameter tube that extends from the top of the reactor pool down into a position in the core grid along the south edge of the core. It has a 9.4x1012 n/cm2/s maximum total flux and 4.5x1012 n/cm2/s maximum thermal flux.

The peripheral irradiation facility (PIF) is a 2.5-inch inner-diameter tube that extends from the top of the reactor pool down into the core grid at the northeast corner of the core.  It has a 5.3x1012 n/cm2/s maximum total flux and 3.1x1012 n/cm2/s maximum thermal flux.

The pneumatic transfer (rabbit) facility makes use of a vacuum system for insertion and extraction of samples in two-inch outer-diameter sample carriers for precisely-timed irradiations. It offers a 3.2x1012 n/cm2/s maximum total flux and 2.1x1012 n/cm2/s maximum thermal flux.

The horizontal beam ports, two portholes that penetrate the north wall of the reactor pool, each have a 6-inch inner-diameter. Beam port #1, which is aligned perpendicularly with the core center, has a maximum total flux of 4.2x1012 n/cm2/s and a maximum thermal flux of a 2.3x1012 n/cm2/s. Beam port #2 approaches the core below center at an angle.  A newly-built external neutron beam line facility is currently installed that uses beam port #2.  A small size (~30 mm diameter) well-collimated thermal neutron beam (cadmium ratio using gold foils = 92) is guided out of the core to an open space where in-situ instrumentation may be set up for testing radiation detectors and chracterizing materials. The maximum thermal equivalent flux is 2.5x106 n/cm2/s at the sample location within the high-vacuum chamber and 4.4x106 n/cm2/s in front of the vacuum chamber. The flux may be controlled with reduced reactor power. See OSU's Nuclear Analysis and Radiation site for more information.

The thermal column irradiation facility, which is situated behind the thermal column extension in the west wall of the reactor pool, offers a very thermalized neutron field in a four-inch by four-inch area for experimentation. It has a maximum total flux on the order of 5x1011 n/cm2/s and a maximum thermal flux of 2.5x1011 n/cm2/s.

Movable vertical dry tubes, with 7-inch and 10-inch diameters, are available for placing experiments at or near the core boundary. A fixed mounting point is provided on an I‑beam which supports the startup source drive above the pool surface, but the tubes can be vertically mounted almost anywhere within the volume of the reactor pool.  When the 7-inch vertical dry tube is placed at the core boundary, the maximum total flux is 1.5x1012 n/cm2/s and the maximum thermal flux is 1.1x1012 n/cm2/s.  When the 10-inch vertical dry tube is placed at the core boundary, the maximum total flux is 1.1x1012 n/cm2/s and the maximum thermal flux is 8.1x1011 n/cm2/s.

Specifications

Reactor Type

Open Pool

Thermal Power

500 kW

Initial Criticality

March, 1961

Fuel

19.5% Enriched U3Si2

Cladding

Aluminum

Moderator

Light Water

Primary Coolant

Light Water

Secondary Coolant

Ethylene Glycol

Experimental Facilities

  • 1.3" Central Irradiation Facility (CIF)

  • Two 6" beam ports

  • 2" rabbit tube

  • 2.5" Auxiliary Irradiation Facility (AIF)

  • 2.5" Peripheral Irradiation Facility (PIF)

  • Graphite Thermal Column

  • 7" dry tubes

  • 10" dry tube

Reactor Pool

  • Depth: 20'

  • Length: 10' 7"

  • Width: 3' 8.5"

  • Volume: 5600 gallons

  • Liner: Epoxy-based paint