Triga reactors

In these studies, samples of approximately 20 irradiated or 5000 unirradiated particles were leached with hot 13M HN03 for about 1 hour to remove surface contamination (uranium) and then activated at ambient temperatures in the TRIGA reactor to produce inventories of the... 

The HELIOS mass separator vat the Mainz TRIGA reactor is one of the few facilities where a gas-jet transportation system has been coupled successfully to a mass separator. Details of the gas-jet system, the integrated skimmer-ion sources, the separator and its collector facilities have been published elsewhere [Maz 80, Maz 81]. Recently, HELIOS was applied for spectroscopic studies of neutron-rich isotopes of praseodymium [Bru 85] and neodymiurn [ Kar 85], Work is in progress in order to replace the existing ion sources by an inductively oupled jplasma ion source (ICP). In case of a successful coupling of the gas-jet with the ICP source it should be possible to ionize any element in the periodic table because temperatures of 6000 -10000 K are reached in the plasma. 

In experiments at the UNILAC accelerator at GSI, Darmstadt, the tantalum isotopes 168 170Ta were transported by the He(KCl) gas-jet and deposited on a polyethylene frit in ARCA II. The dissolution of the collected tantalum activity from the frit was investigated as a function of the a-HiB concentration. Because of the smaller column size in ARCA II (1.6x8 mm) which might cause an earlier breakthrough of the tetravalent and trivalent metal ions it was desirable to decrease the a-HiB concentration. Even with 34 pL of 0.025 M a-HiB, dissolution of >75% of the tantalum activity was achieved in 2 s. The time required for the complete elution of Ta from the column was about 4 s. Similar experiments performed at the Mainz TRIGA reactor with "mNb confirm this result as shown in Figure 14. 

Mercury and Gallium a General Electric TRIGA reactor provides slow neutrons for the neutron activation analysis of these metals at the 10-50-ppb detection level. 

A solid solution of uranium and zirconium hydrides is used as fuel in TRIGA reactors. Uraruum hydride is often pyrophoric and must be handled with care. It has been used to prepare finely divided uranium metal by reacting massive metal with hydrogen, then crushing the brittle hydride and heating it in vacuum to drive off hydrogen. 

When short-lived isotopes are involved, a higher activity is produced by irradiating the sample in a reactor that can be pulsed (see Lenihan et al.). Such a reactor producing a high flux of about 10 neutrons/(m s) for a short period of time (milliseconds) is the TRIGA reactor, marketed by General Atomic. 

Typical of reports on devices used to produce nuclear particles are the following Lorenz and Scheer (558) on the use of a Triga Reactor in a nuclear medical department Yule, Lukens, and Guinn (1021) on the use... 

FIGURE 2 Representative reactor pumped laser signals (a) CO RPL excited by Sandia Labs SPR-II (FBR) (b) Ar RPL excited by Sandia Labs SPR-II (FBR) (c) Xe RPL excited by Sandia Labs ACRR (analogous to pulsed TRIGA reactor). 

Another relatively cotmnon research reactor, the pulsed TRIGA reactor, operates by pulsing from a very low initial power level using control rods. The pulsed TRIGA reactor can be pulsed more frequently because it typically is located at the bottom of a tank of water which acts as both coolant and shield. The neutron spectmm of a TRIGA reactor also has a much lower average energy, which reduces or eliminates the need for neutron-moderator material in the laser apparatus. 

TRIGA reactor, sketch of the reactor core with surrounding water tank and cylindrical graphite reflector with rotating irradiation rack. These and other important parts of the core are designated in the sketch (Berwanger 1965)... 

Numerous other research reactors with a neutron flux higher than the TRIGA reactor but not as high as the ILL reactor are used on a routine basis for the production of radionuclides such as Mo/ Tc, and other radionuclides for medical diagnosis and treatment. Intense y-ray sources based on Co used for external medical radiation treatment and industrial applications are produced in these reactors. 

Triga reactors have been used worldwide, both in developed and in developing countries, so they have been operated in mote than a dozen countries. Indonesia has operated Triga reactor since 1964 at Bandung Reactor Centre. 

It has been proposed that we measure the k of a spent fuel assembly by using a subcritical assembly wherein a neutron source multiplication measureihent, made with the fuel assembly of an unknown k , is compared with the same measurement performed with a fuel asisembly of known k . The dwice in which this measurement is performed is called a k >meter, and it requires that the keff of the initial suhcriti-cal assembly be measured. The purpose of this paper is to report the results of subcritical experiment performed with the Pennsylvania State University Breazeale TRIGA reactor to determine the keff of a subcritical assembly using the asymmetric source method (ASM). Similar experiments would be performed with the k -meter to establish the keff of the initial subcritical assembly. 

Research reactors in Latin America have several common features. The first one is that with the exception of some critical facilities, all of them are water cooled, either Material Testing Reactor (MTR) or Training Research Isotope production General Atomic (TRIGA) reactor types, and, with the exception of the critical facilities and very low power reactors, wet storage is the form used for operational storage of spent fuel. 

In Mexico there is one operational research reactor, a 1 MW TRIGA reactor, and one operational subcritical facility. Another reactor, a SUR-100 homogeneous reactor, was decommissioned after shutdown in 1984, and another subcritical facility is in the condition of shut down . 

Mr. Graham informed that the current nuclear scene in UK is based on the following types of reactors Magnox (3350 MWe), AGR (8380 MWe) and PWR (1175 MWe). Any additions will need to come from private industry. No FBR or MTR is now in operation in UK. There are some low power University reactors and a TRIGA reactor at Imperial Chemical Industries. Spent fuel reprocessing is undertaken at Sellafield and Dounray. 

The determination of Pb by reactor activation normally requires chemical separation of the 3.3 h pure emitter ° Pb. The use of the short-lived isomeric state 207mp j activated by the Pb(n,y) ° Pb and PbfnjnO Pb reactions is a useful instrumental alternative. The method has been investigated by Lukens using the triga reactor, and by Wiernik and AmieF and Henkelmann et Again the sensitivity of the method will depend upon the reactor neutron spectrum used. In the latter case, a reactor fast-neutron flux of 1.8 X10 cm s" allowed analysis with a limit of detection of 200 MS, somewhat poorer than the other methods. However, in such a flux spectrum the interference from other (n,y) activations will be considerably reduced. 

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