PULSTAR Reactor
The PULSTAR is a 1-MW pool-type nuclear research reactor which is administered by the Nuclear Reactor Program and located in Burlington Laboratory on the N.C. State north campus. The PULSTAR fuel is 4% enriched, pin-type fuel consisting of uranium dioxide pellets in zircaloy cladding (see reactor specifications). This fuel gives the PULSTAR Reactor response characteristics that are very similar to commercial light water power reactors. These characteristics allow teaching experiments to measure moderator temperature and power reactivity coefficients including doppler feedback.
PULSTAR Reactor Facility
The heavy fuel load in the PULSTAR, combined with a relatively high fuel-to-moderator ratio, results in high fast neutron leakage at the core boundary. This causes a large thermal neutron “reflector hump” at the core periphery, (see Figure #1 below)yielding high thermal neutron fluxes at the sample irradiation facilities and beamports (see Table #1 below).
| Table #1: PULSTAR Irradiation and Beamport Experimental Facilities |
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| Facility | Description | Intensity |
|---|---|---|
| Rotating Exposure Ports 4 in-pool, ex-core |
2.5” ID wet sample irradiation terminus | 1.0×1013 thermal n/cm2/sec 1.0×1012 fast n/cm2/sec |
| Dry Exposure Ports 2 in-pool, ex-core |
1.25” ID dry sample irradiation terminus | 4.0×1012 thermal n/cm2/sec 1.0×1011 fast n/cm2/sec |
| Pneumatic Terminus 1 in-pool, ex-core |
1.25” ID fast rabbit sample transfer system | 1.0×1013 thermal n/cm2/sec 1.0×1012 fast n/cm2/sec |
| Pool Standpipes 4 in-pool, ex-core |
3.5” ID dry sample irradiation positions | 1.0×1011 thermal n/cm2/sec 5.0×109 fast n/cm2/sec |
| Beamport #1 | 6-in. diameter radial tube | 1.0×1012 thermal n/cm2/sec at core end |
| Beamport #2 | 6-in. diameter tangential ‘through’ tube | 1.0×1012 thermal n/cm2/sec at centerpoint |
| Beamport #3 | 8-in. diameter radial tube | 1.0×1012 thermal n/cm2/sec at core end |
| BP#4: Neutron Powder Diffraction Facility | 6-in. diameter radial tube | ~0.5×105 1.4Å n/cm2/sec on target |
| BP#5: Neutron Imaging Facility | 6-in. diameter radial tube | ~5.0×106 thermal n/cm2/sec at 6.5 meter imaging plane |
| BP#6: Intense Positron Source Facility | 12 in. by 12 in. sq. radial tube | 5-6×108 positrons/second at target; beam spot diameter is 25 mm; e+ energy variable up to 30 keV |
| Thermal Column: Ultra-Cold Neutron Source Facility | 5’x5’x7’ cavity in biologic shield adjacent to reactor core | Projected intensity of 6 to 16 million UCN’s per second |