[en] Objective: To verify the role of metronidazole-amino-acidum-natrium (CMNa) in enhancing radiosensitivity through analysis of survival rates from a multicenter prospective randomized controlled trial. Methods: 152 patients with esophagus carcinoma were randomly divided into two groups(test group A and control group B). The patients in group A were given intravenous drip CMNa 800 mg/m² three times weekly during the whole period of radiotherapy. Patients in group B were treated by radiotherapy alone with the effects and safety evaluated and survival follow-up were carried out. Results: 150 (98.7%) patients completed their designed treatment in which 101(67.3%) patients were allotted to group A and 49 patients to group B. Among the 69 stage I-III a patients in Group A, the 1-, 2- and 3-year survival rates were 77%, 54% and 28%, with a median of 27 months. Among the 38 stage I-III a patients in Group B, they were 71% ,25%, 19% and 16 months(χ² = 4.23, P = 0. 040). The rate of adverse reactions was 37 % and 39 % in group A and group B (χ² = 0.03, P = 0. 859), without any neurotoxicity observed. Conclusions: CMNa, being an effective radiosensitizer, can improve survival rates of stage I-III a esophageal carcinoma patients to certain extent, with safety proved as shown in this study. (authors)

[en] The article mainly discusses the aims and methods of environment radiation background investigation in the stage of construction of Tianwan Nuclear Power Plant. The investigation schedule includes the supervision scope, point-distribution, lab analysis, quality control methods and sample measurements. The investigation results are also presented. (authors)

[en] The scheme design of the repository for radioactive waste is introduced according to the traits of radioactive waste in Jiangsu province, such as the style of the repository, lifting facilities, the step for preventing or controlling flood, the aseismatic measure, the pollution prevention and so on. This ensured the radioactive waste and the waste radioactive sources to be stored in security, the area environment not to be polluted. It can improve the use of nuclear technology in Jiangsu province. (authors)

[en] In this paper, the source-free efficiency calibration method is used to verify the HPGe γ-spectrometer. A ⁶⁰Co standard point source and three body sources were used in the efficiency calibration with the LabSOCS code. The results show that this method can be used as a supplement method to efficiency calculation and laboratory quality control. Meanwhile, the impact factors of source-free efficiency fitting were analyzed. (authors)

[en] Objective: To study and establish the regulatory Limits of radiological protection for minerals associated with radionuclides. Methods: To deduce the limits according to the international and domestic references in combination with China's practices. Results: The regulatory Limits of radiological protection for minerals associated with radionuclides have been suggested. Conclusion: It is necessary and practical to establish the limits which are of great importance to the health of the public as well as the worker's