Practice for Calculation of Dose Equivalent Xenon (DEX) for Radioactive Xenon Fission Products in Reactor Coolant

10.1520/d7727 ◽  
2013 ◽  
Author(s):  
Author(s):  
Huaibin Li ◽  
Yaru Fu ◽  
Lanfang Mao ◽  
Qiliang Mei

When fuel rods have defects, the fission products in the fuel rods will come out and enter the reactor coolant through the defects. The release of the fission products will result in the increase of radiation dose, the indeterminacy of the fuel management and will influence the economics and safety of the nuclear power station. Based on the analysis of the typical nuclides activities in reactor coolant, the evaluation of the defect fuel rods can be realized. This paper studied the related analysis around the world and determined the methods to evaluate the number, the defect type (open or tight) and the burn-up of the defect fuel rods. The evaluation method of this paper can be used to evaluate the defects of fuel rods, and can provide valuable information for the fuel management and dose analysis, and also can be a useful technical support to the operation of nuclear power station.


Author(s):  
Hans Ashar ◽  
Eugene Imbro ◽  
David Terao

Appendix J of 10 CFR 50, “Primary Reactor Containment Leakage Testing for Water-Cooled Power Reactors,” sets the testing requirements for preoperational and periodic verification of the leak-tight integrity of the primary reactor containment, including systems and components which penetrate containment of light water-cooled power reactors, and establishes the acceptance criteria for such tests. The purposes of the tests are to assure that leakage through the primary reactor containment and systems and components penetrating primary containment would not exceed allowable leakage rate values as specified in the plants’ technical specifications. The current Appendix J requirements provide two options for performing the tests. Option A (fully deterministic) requires that after the preoperational leakage rate tests, a set of three integrated leak rate tests (ILRT — termed as Type A tests) shall be performed, at approximately equal intervals during each 10-year service period. Option B does not provide a quantitative requirement for scheduling the periodic Type A tests. However, NEI 94-01, “Industry Guideline for Implementing Performance-Based Option of 10 CFR Part 50, Appendix J,” and NRC Regulatory Guide (RG). The containment is a vital engineering safety feature of a nuclear power plant. It encloses the entire reactor and reactor coolant system and serves as a final barrier against the release of radioactive fission products to the environment under various accident conditions. Containment design is based on pressure and temperature loadings associated with a loss-of-coolant-accident resulting from a double-ended rupture of the largest pipe in the reactor coolant system. Recently, it has been reported that in certain 1.163, “Performance-Based Containment Leak Test Program,” provide guidelines for determining the frequencies of preoperational and periodic leak rate tests using a performance based approach. The Option B requirements and NEI 94-01 guidance are based on NUREG-1493, “Performance Based Containment Leak-Test Program.” Based on the information provided by the operating data and their risk significance, the study calculated the change in risk (in person-rem) to public for the 15 alternatives considered in the study. However, recognizing the non-sensitivity of risk to change in Type A leak rate testing frequencies, as depicted in NUREG-1493, a number of licensees are proposing changes to their Type A test frequencies using NRC risk-informed guidance in RG 1.174, “An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis.” The paper discusses certain key deterministic aspects of the risk-informed decision for the plant-specific changes in the ILRT frequencies.


1995 ◽  
Vol 25 (3) ◽  
pp. 475-480 ◽  
Author(s):  
Stephen V. Musolino

For over 30 years, Ernest Sternglass (recently joined by Jay Gould) has claimed that large occurrences of health effects result from small exposures to ionizing radiation. A recent study published in the Journal claimed to show a “supralinear” dose-effect relationship versus curies per million persons. The authors of this article show that Sternglass and Gould did not follow accepted scientific methods, never calculated the dose equivalent to the population studied, misinterpreted the raw data, and did not evaluate any possible confounding factors that could influence the observed breast cancer mortality. The reanalysis of the raw data shows that, while there may have been changes in the mortality patterns from breast cancer in the four geographical regions reported, Sternglass and Gould failed to demonstrate a relationship between the operational histories of the Haddam Neck, Millstone, and Indian Point reactors and breast cancer mortality.


1976 ◽  
Vol 32 ◽  
pp. 169-182
Author(s):  
B. Kuchowicz

SummaryIsotopic shifts in the lines of the heavy elements in Ap stars, and the characteristic abundance pattern of these elements point to the fact that we are observing mainly the products of rapid neutron capture. The peculiar A stars may be treated as the show windows for the products of a recent r-process in their neighbourhood. This process can be located either in Supernovae exploding in a binary system in which the present Ap stars were secondaries, or in Supernovae exploding in young clusters. Secondary processes, e.g. spontaneous fission or nuclear reactions with highly abundant fission products, may occur further with the r-processed material in the surface of the Ap stars. The role of these stars to the theory of nucleosynthesis and to nuclear physics is emphasized.


Author(s):  
R. J. Lauf

Fuel particles for the High-Temperature Gas-Cooled Reactor (HTGR) contain a layer of pyrolytic silicon carbide to act as a miniature pressure vessel and primary fission product barrier. Optimization of the SiC with respect to fuel performance involves four areas of study: (a) characterization of as-deposited SiC coatings; (b) thermodynamics and kinetics of chemical reactions between SiC and fission products; (c) irradiation behavior of SiC in the absence of fission products; and (d) combined effects of irradiation and fission products. This paper reports the behavior of SiC deposited on inert microspheres and irradiated to fast neutron fluences typical of HTGR fuel at end-of-life.


Author(s):  
T. E. Mitchell ◽  
R. B. Schwarz

Traditional oxide glasses occur naturally as obsidian and can be made easily by suitable cooling histories. In the past 30 years, a variety of techniques have been discovered which amorphize normally crystalline materials such as metals. These include [1-3]:Rapid quenching from the vapor phase.Rapid quenching from the liquid phase.Electrodeposition of certain alloys, e.g. Fe-P.Oxidation of crystals to produce amorphous surface oxide layers.Interdiffusion of two pure crystalline metals.Hydrogen-induced vitrification of an intermetal1ic.Mechanical alloying and ball-milling of intermetal lie compounds.Irradiation processes of all kinds using ions, electrons, neutrons, and fission products.We offer here some general comments on the use of TEM to study these materials and give some particular examples of such studies.Thin specimens can be prepared from bulk homogeneous materials in the usual way. Most often, however, amorphous materials are in the form of surface films or interfacial films with different chemistry from the substrates.


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