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The Young Members Group works to encourage and enable all young professional members to be actively involved in the efforts and endeavors of the Society at all levels (Professional Divisions, ANS Governance, Local Sections, etc.) as they transition from the role of a student to the role of a professional. It sponsors non-technical workshops and meetings that provide professional development and networking opportunities for young professionals, collaborates with other Divisions and Groups in developing technical and non-technical content for topical and national meetings, encourages its members to participate in the activities of the Groups and Divisions that are closely related to their professional interests as well as in their local sections, introduces young members to the rules and governance structure of the Society, and nominates young professionals for awards and leadership opportunities available to members.
2021 Student Conference
April 8–10, 2021
North Carolina State University|Raleigh Marriott City Center
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A day in the life of the nuclear community
The November issue of Nuclear News is focused on the individuals who make up our nuclear community.
We invited a small group of those individuals to tell us about their day-to-day work in some of the many occupations and applications of nuclear science and technology, and they responded generously. They were ready to tell us about the part they play, together with colleagues and team members, in supplying clean energy, advancing technology, protecting safety and health, and exploring fundamental science.
In these pages, we see a community that can celebrate both those workdays that record progress moving at a steady pace and the exceptional days when a goal is reached, a briefing is delivered, a contract goes through, a discovery is made, or an unforeseen challenge is overcome.
The Nuclear News staff hopes that you enjoy meeting these members of our community—or maybe get reacquainted with friends—through their words and photos.
Fei-Jan Tsai, Min Lee
Nuclear Technology | Volume 205 | Number 4 | April 2019 | Pages 524-541
Technical Paper | dx.doi.org/10.1080/00295450.2018.1500831
Articles are hosted by Taylor and Francis Online.
This study assessed the effectiveness of in-vessel retention (IVR) in terminating the progression of an accident sequence initiated by a station blackout and large loss-of-coolant accident in a pressurized water reactor with thermal power of approximately 5000 MW. In the IVR design, external reactor vessel cooling is established by flooding of the reactor cavity. A water channel is introduced into the outer wall of the reactor vessel, and an insulated layered structure is added around the vessel. The amount of heat removed from the corium pool in the vessel lower plenum is limited by the critical heat flux (CHF) at the outer surface of the vessel wall. An integrated assessment was conducted in three steps. First, the responses of the reactor coolant system and containment were simulated using MELCOR. The predicted transient heat load at the vessel wall was then fed into RELAP5-3D, where the flow of natural, buoyancy-driven convection within the IVR water channel was simulated. Finally, the main thermal-hydraulic parameters in the IVR channel were substituted into the ULPU, SULTAN, SBLB, and MELCOR CHF correlations, and the effectiveness of IVR was assessed. The MELCOR simulation demonstrated that the heat load at the vessel wall of the lower plenum is dependent on the configuration of the debris. The heat flux to the vessel wall reached a maximum at 483 min, at an inclination angle of approximately 68 deg. The peak heat flux moved from a small inclination angle to a larger angle as the accident progressed. Both MELCOR and RELAP5-3D calculations predicted a gradual buildup of natural convection flow within the IVR channel following the application of a heat load to the vessel wall. The MELCOR code significantly overpredicts the mass flow of natural convection flow. Both codes predicted that the flow would experience large-amplitude fluctuations as the water in the IVR flow channel reached saturation. These fluctuations were attributed to instability induced by two-phase flow.
If the inlet temperature can be kept sufficiently low to obviate boiling in the IVR channel, RELAP5-3D predicts that the channel flow will approach an approximately steady state. The selected CHF correlations predicted significantly different CHFs. The MELCOR correlation, which is a correlation based on pool boiling, produced the most conservative predictions, and the CHFs predicted by SBLB had the highest value. The minimum margin was found between 55 and 75 deg in all correlations. With the exception of the MELCOR correlation, the CHF ratio predicted by the other three correlations is greater than 1.2.