Transient nuclear test

The data from Laboratory A showed that, for any sample, /90 was closely related to both the arithmetic and geometric means of fs9 and /91-Subsequent investigation has shown that this rule applies to other types of bursts as well as the Transient Nuclear Test (8). Application of this rule, and requirements that /89, /90, and f91 have the proper order, helped to eliminate many spurious results. 

Correlation of Radionuclide Fractionation in Debris from a Transient Nuclear Test... 

Fractionation correlation techniques have been applied to cloud, fallout, and ground-filter samples from the Transient Nuclear Test of January 1965. Although safety analysts do not consider fractionation effects to be of operational importance for this type of event, analysis of such data provides insight into the mechanisms of debris formation. The results show many similarities to the correlations observed for fallout. Those dissimilarities found indicate the importance of escape processes to the formation mechanisms for this type of debris. 

Tlhis paper describes the physical and radiochemical characteristics of selected debris from the Kiwi Transient Nuclear Test (TNT) (6, 7). This transient test was conducted in Nevada by the Los Alamos Scientific Laboratory (LASL), and produced approximately 3 X 1020 fissions (1). Zero time was 1059 PST on 12 January 1965. About 5% of the reactor core was vaporized, and some 68% was converted to a cloud of particulate. The measured maximum temperature was 4250°K. (7). Large pieces of fuel rods were recovered near ground zero. 

The advent of the space age, the testing of intercontinental ballistic missiles, the use of space probes, the existence of radiation belts in outer space, and the increasing utilization of military and civilian satellites have triggered further studies on the effects of nuclear radiation on all types of materials, including expls, propints, pyrots and related materials. Nuclear radiation effects studies range from steady-state to transient environments, from ground zero to upper atmosphere levels and from underground nuclear tests to simulation techniques in the laboratory which in turn cover all phases of vulnerability and survivability... 

In order to make use of this transient, the contributions of the natural and bomb radiocarbon had to be separated. Three sets of observations went into this separation. First, use was made of measurements on surface waters collected very early in the nuclear testing era (Broecker etal., 1960) and also with results of measurements on prenuclear growth ring-dated corals and mollusks (Drulfel and Linick, 1978 Drulfel, 1981, 1989). Second, use was made of the tritium released to the atmosphere during nuclear tests. As this bomb-test tritium swamped the natural tritium present in the ocean, the vertical distribution of tritium in the sea could be used to establish the limit of penetration of bomb radiocarbon. Finally, based on the radiocarbon analyses made on thermocline waters free of bomb tritium, it was shown that there was a close correlation between the natural ratio and the dissolved silica... 

An impulse graphite reactor IGR (O Fig. 59.10) with a central channel to test fuel assemblies at the NPP transient operation modes and a research reactor IVG-1 (O Fig. 59.11) to test full-scale fuel assemblies (FA) of nuclear rocket engines of 3 x 10 -4 x 10 N and higher thrust were built at the Semipalatinsk nuclear test site. Further, an experimental NPP model of a low thrust was mounted at the same site. 

Nuclear bomb produced " 002 and (as HTO) have been used to describe and model this rapid thermocline ventilation (Ostlund et ah, 1974 Sarmiento et ah, 1982 Fine et al., 1983). For example, changes in the distributions of tritium (Rooth and Ostlund, 1972) in the western Atlantic between 1972 (GEOSECS) and 1981 (TTO) are shown in Fig. 10-10 (Ostlund and Fine, 1979 Baes and Mulholland, 1985). In the 10 years following the atmospheric bomb tests of the early 1960s, a massive penetration of F1 (tritium) into the thermocline has occurred at all depths. Comparison of the GEOSECS and TTO data, which have a 9 year time difference, clearly shows the rapid ventilation of the North Atlantic and the value of such transient" tracers. A similar transient effect can be seen in the penetrative distribution of manmade chlorofluorocarbons, which have been released over a longer period (40 years) (Gammon et al., 1982). 

Although the transient test was orders of magnitude below a nuclear weapon in regard to energy release and temperature achieved, the debris showed many similarities to fallout. These included not only the size and appearance of the particles but also the correlation properties of various radionuclides. Dissimilarities in the correlations and the variation of specific activity with particle type confirm expectations of the importance of escape processes to the formation mechanisms for this type of debris. This study shows that data-correlation techniques developed for fallout characterization are also useful in studying reactor debris. 

Studies on the effect of pulsed nuclear reactor irradiation were conducted on RD-1333 Pb azide (Ref 254). Bulk samples of RD-1333 were exposed to a total dose of 2.0 x 1014 n/cm2 from an unmoderated, unreflected, prompt pulsed reactor in a pulse 40 to 50 psec full-width at half-maximum. Analyses of the Pb azide which included the vacuum stability test, expln temp test, and the detonation velocity test, did not show any changes due to the transient radiation environment... 

Simulation tests of abnormal transients caused by the nuclear heat utilization system... 

After obtaining new licences from Japanese government, some simulation tests of abnormal transients caused by the nuclear heat utilization system which will be connected to the HTTR are planned in order to contribute the design of the nuclear heat utilisation system. The test results will be utilized for the validation of analytical codes as well as both of the HTTR-IS system design and the future VHTR design. Two kinds of simulation tests are planned. 

One is the secondary- coolant reduction test by partial secondary loss of coolant flow in order to simulate the load change of the nuclear heat utilization system. This test will demonstrate that the both of negative reactivity feedback effect and the reactor power control system brings the reactor power safely to a stable level without a reactor scram, and that the temperature transient of the reactor core is slow in a decrease of the secondary coolant flow rate. The test will be perfonned at a rated operation and parallel-loaded operation mode. The maximum reactor power during the test will limit within 30 MW (100%). In this test, the rotation rate of the secondary helium circulator will be changed to simulate a temperature transient of the heat utilisation system in addition to cutting off the reactor-inlet temperature control system. This test will be performed under anticipated transients without reactor scram (ATWS). 

Nine explosives and propellants were subjected to a transient burst of about 1 msec duration which resulted from fission of about 10 atoms of [62]. The materials were tested with 3.6-g samples of TATB, DATE, TACOT, HNS, lead styphnate, black powder, and three composite propellants. The lead styphnate sample detonated, but since the samples were hurled 500 ft by the nuclear excursion there was some question whether this resulted from impact rather than irradiation. The melting point was lowered from 216 to 208°C and the 5-sec explosion temperature (Table XI) was lowered from 299 to 268°C. None of the other materials tested showed evidence of gross radiation damage. 

Transient tracers which are introduced sporadically in a system, e.g., radionuclides introduced by testing of nuclear weapons, and from discharges from nuclear reactors. 

Several cosmogenic tracers also qualify as transient tracers at the present time, because of an appreciable contribution from anthropogenic sources (Table 3). Thus, the nuclides H, (produced in appreciable amounts in nuclear weapons testing), tritugenic He and I (which has also been produced in large amounts by nuclear weapons tests and operation of nuclear power plants), serve as (useful) transient tracers in some geophysical reservoirs. 

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