UCI Nuclear Reactor

The UCI Nuclear Reactor

is operated by the Department of Chemistry for use in radiochemistry applications. The reactor is a 250 kilowatt steady-state power Mark I TRIGA reactor built by General Atomics. Pulsing is possible to about 1000 megawatts. The reactor first became critical in November 1969. TRIGA reactors are water and zirconium hydride moderated to be especially safe for training and research purposes. Fuel is uranium enriched to less than 20% in U-235. The facility specializes in neutron activation analysis  (NAA) using thermal and epi-thermal neutrons. It also provides a source of radioisotopes and radiation for testing of processes for separating lanthanides and actinides (10)– an important step for future recovery of partly used nuclear reactor fuel. Typical analytical work has included measurements on the JFK assassination bullet lead(1), mercury levels in ancient specimens of swordfish, and tuna(2), sculptures in the Getty Museum in Los Angeles(3), ancient bones(4), samples of mosaics(5), and tracing manganese pollutants (6,8).  Work is also being done to test systems and detectors for homeland security screening applications (7,9).  The facility has provided short-lived radioactive isotopes on occasion for tracer studies in industry and medicine.

  1. Guinn, V.P. "JFK Assassination Bullet Analyses". Analytical Chemistry, 1979, 51, 484A-493A.
  2. Miller, G. E.; Grant, P. M.; Kishore, R.; Steinkruger, F. J.; Rowland, F. S.; Guinn, V. P., Mercury Levels in Museum Specimens of Tuna and Swordfish, Science, 1972, 175, 1121.
  3. Miller, G. E.; Sangermano, L.; Bunker, D. L., Chemical Analysis of Marble Sculptures: Crouching Aphrodite and the Westmacott Jupiter in the J. Paul Getty Museum, Getty Museum Journal, 1977, 5, 149.
  4. Manea-Krichten, M. C.; Patterson, C.E.; Miller, G.E.; Settle, D.; Erel, Y., Comparative Increases of Lead and Barium with Age in Human Tooth Enamel, Rib, and Ulna, The Science of the Total Environment, 1991, 107, 179-203.
  5. Stulik, D.; Miller; G. E., Miller; D. A., Investigating the Mysteries of the Last Judgment Mosaic in Prague, Transactions of the American Nuclear Society, 2003, 89, 755.
  6. Miller, G.E.; Ericson, J. E.; Rindernecht, A.; and Kleinman, M. T., Tracking Manganese Exposure Using INAA, Transactions of the American Nuclear Society, 2003, 89, 760.
  7. Maglich, Bogdan C.; Chuang, Tsuey-Fen;  Lee, Mu Young; Druey, Christian; Kamin, George;  Miller, George E.,  MiniSenzor’ for Humanitarian Noninvasive Chemical Identification of UXO Fillers, presented at "International Conference on Requirements and Technologies for the Detection, Removal and Neutralization of Landmines and UXO", Brussels Sept. 15–18, 2003.
  8. Ericson, J. E.; Rinderknecht, A.; Chan, T. J.; Kleinman, M. T.; Miller, G. E., Enamel biomarker for assessing and tracing heavy metal exposure, Geochimica et Cosmochimica Acta Supplement, Vol. 69, Issue 10, Supplement 1, Goldschmidt Conference Abstracts 2005., page.A203.
  9. Beyerle, Albert G.; Walker, David M.; Miller, George E.;  Evaluation of HPXe-Based Nuclear Explosion Monitor Applications, presented to National Nuclear Security Administration, September 2006.
  10. Pearson, J.; Jan, O.; Miller, G. E.; and Nilsson, M., Studies of high linear energy transfer dosimetry by 10B(n,α)7Li reactions in aqueous and organic solvents. Journal of Radioanalytical and Nuclear Chemistry: 2012, 292, 719-727.

Oval: UCI Nuclear Science Group 2011-2012Nuclear_Group_4A.tif

Use of The Reactor

The maximum steady thermal neutron flux is about 5 x 1012 neutrons/sec.cm2. Large numbers of samples can be simultaneously irradiated at a flux of about 0.8 x 1012. Pneumatic transfer systems can be used to return samples in 2 seconds, or 1/2 second respectively. For the fast system a thermal or fast flux terminus is available. Pulses provide the equivalent of a one minute irradiation, but with the flux peaking near 1016n/sec.cm2.

Support Facilities

Three gamma-ray spectrometer systems are available, each with an HPGe detector and modern software systems. One is a 30% detector, one a 60% “portable” detector, the third is a 25% well detector, coupled with an 300 sample automatic sample changer for long sequenced counting. A Compton suppression set-up is under construction. Sodium iodide and LaBr3 gamma detectors, proportional beta counters, and a liquid scintillation system are also available. Chemistry laboratories are available within the facility for radiochemistry applications. Also available is a gamma irradiator with a large chamber for kiloGray radiation exposure studies.


The primary function of the reactor is to support the educational programs at UCI. Courses in Radioisotope Techniques, Nuclear and Radiochemistry, and Nuclear Reactor Fundamentals are offered in the chemistry department's elective curriculum. Course in the Nuclear Fuel cycle are offered in the department of Chemical Engineering and Materials Science. A summer institute course is offered in Fundamentals and Practices in Nuclear Reactor Operations from which students are encouraged to continue studies to obtain an NRC reactor operator’s license.

Some services of the reactor and radiochemistry analysis equipment are also available to other educational institutions for class use free of charge (supported by a Department of Energy grant) and for research or business use at fixed costs. Basic reactor charges are approximately $150 per hour (1 hour minimum) and $50 per hour (1 hour minimum) for spectrometer use. Other costs for research-based analytical determinations will be quoted upon request. Routine analytical services are also offered by arrangement with General Activation Analysis, Inc., who should be contacted directly for assistance.

UCI is a member of the National Science and Security Consortium (NSSC) funded by the National Nuclear Security Administration (NNSA) encompassing seven universities and several National Laboratories designed to provide students with increased access to nuclear science education, leading to a career at a National Laboratory.
For more information please contact:

Dr. G. E. Miller, Reactor Supervisor, (949) 824-6649, e-mail:

Professor A.J. Shaka, Facility Director, (949) 824-8509, e-mail:

Professor M. Nilsson, Department of Chemical Engineering and Materials Science, (949) 824-2800 , e-mail:



Tours of the facility are available for interested groups of 5 - 30 individuals with sufficient notice. Names of all those visiting must be provided in advance. All individuals entering are subject to security screening requirements, including verification of personal identity. Demonstrations of NAA and laboratory work for older students can also be scheduled by arrangement. We regret that larger groups cannot be admitted, nor children under 10 years old. While the radiation levels within the facility are extremely minimal (barely measurable above background), females who are in early stages of pregnancy are advised that very slight additional risks to their fetus from radiation and chemical exposure may be present, as in any visit to a scientific laboratory.
For tour arrangements please contact Mr. Jonathan Wallick, Nuclear Laboratory Engineer, (949) 824-6082, e-mail or

Dr. George E. Miller, Reactor Supervisor and Facility Director at (949) 824-6649, e-mail:


We regret no individual or routine tours are available.