Preliminary risk assessment of in-vessel leakage accident in ITER.

The ITER project is one of the largest international cooperative scientific projects in the world, aiming to verify the feasibility of magnetic confinement controlled nuclear fusion technology and provide a technical basis for the subsequent construction of fusion energy power stations. The success or failure of ITER will greatly affect the commercialization process of fusion energy. The probabilistic safety assessment (PSA) was a powerful means to evaluate the risk and reliability of nuclear facility and achieved great success in safety assessment of fission power plants. Based on this, the PSA progress for ITER was proposed in this paper. And the in-vessel leakage accident was investigated to verify the effectiveness of proposed method. The result shows the maximum possible radiological consequences of ITER in-vessel leakage accident of ITER is 1.6E-3 mSv, and the frequencies of this consequence is 1.63E-8/year. The reason of this consequence was also discussed in this paper. Those result could provide some valuable reference for radiation risk assessment and safety supervision of fusion commercial reactor in the nuclear future.

Reactivity disturbance suppression method for small modular reactors based on core coolant flow control.

Small modular reactors (SMR) have an exceptionally wide range of applications due to their flexibility. But the reactivity of SMR is more susceptible to disturbance than that of large commercial reactors, which may cause the core power to deviate from the set value, and the limited internal space makes it difficult for SMR to compensate or adjust for reactivity disturbance by setting a sufficient number of control rods as in large commercial reactors. Therefore, in order to improve the operational stability of SMR, a method is proposed to indirectly change the nuclear fuel temperature by adjusting the coolant flow rate and thus compensate the reactivity disturbance by the Doppler effect of nuclear fuel resonance absorption. Simulation experiments show that the method can effectively eliminate reactive disturbances that cannot be completely eliminated by control rods under the conditions of restricted SMR space and limited number of control rod sets, thus providing operational stability of SMR.

Evaluation of Prospective HLA-B*13:01 Screening to Prevent Dapsone Hypersensitivity Syndrome in Patients With Leprosy.

Importance: Dapsone hypersensitivity syndrome (DHS) is the most serious adverse reaction associated with dapsone administration and one of the major causes of death in patients with leprosy, whose standard treatment includes multidrug therapy (MDT) with dapsone, rifampicin, and clofazimine. Although the HLA-B*13:01 polymorphism has been identified as the genetic determinant of DHS in the Chinese population, no studies to date have been done to evaluate whether prospective HLA-B*13:01 screening could prevent DHS by identifying patients who should not receive dapsone. Objective: To evaluate the clinical use of prospective HLA-B*13:01 screening for reduction of the incidence of DHS by excluding dapsone from the treatment for patients with HLA-B*13:01-positive leprosy. Design, Setting, and Participants: A prospective cohort study was conducted from February 15, 2015, to April 30, 2018, in 21 provinces throughout China. A total of 1539 patients with newly diagnosed leprosy were enrolled who had not received dapsone previously. After excluding patients who had a history of allergy to sulfones or glucose-6-phosphate dehydrogenase deficiency, 1512 individuals underwent HLA-B*13:01 genotyping. All of the patients were followed up weekly for the first 8 weeks after treatment to monitor for adverse events. Exposures: Patients who were HLA-B*13:01 carriers were instructed to eliminate dapsone from their treatment regimens, and noncarrier patients received standard MDT. Main Outcomes and Measures: The primary outcome was the incidence of DHS. The historical incidence rate of DHS (1.0%) was used as a control. Results: Among 1512 patients (1026 [67.9%] men, 486 [32.1%] women; mean [SD] age, 43.1 [16.2] years), 261 (17.3%) were identified as carriers of the HLA-B*13:01 allele. A total of 714 adverse events in 384 patients were observed during the follow-up period. Dapsone hypersensitivity syndrome did not develop in any of the 1251 patients who were HLA-B*13:01-negative who received dapsone, while approximately 13 patients would be expected to experience DHS, based on the historical incidence rate of 1.0% per year (P = 2.05 × 10-5). No significant correlation was found between other adverse events, including dermatologic or other events, and HLA-B*13:01 status. Conclusions and Relevance: Prospective HLA-B*13:01 screening and subsequent elimination of dapsone from MDT for patients with HLA-B*13:01-positive leprosy may significantly reduce the incidence of DHS in the Chinese population.