873 publications from this institution
The current AREVA Gen 3+ PWR designs (EPR™ and ATMEA1) are based on the proven defense-in-depth safety concepts inherited from their predecessors, the French “N4” and the German “Konvoi” reactors. Complemented by specific enhancements, including higher redundancy and diversity as well as the use of passive systems, this leads to very low values of the core damage frequency (CDF). Notwithstanding this very low probability, dedicated design measures have been implemented to improve the response of the plant in case of a postulated severe accident (SA) with core melting. This way not only the frequency of large-early-releases (LERF) but also the related radiological consequences are drastically reduced. Situations that potentially lead to high loads that can challenge the short-term integrity of the containment, like RPV melt-through under high pressure, energetic hydrogen/steam explosions, as well as long-term containment failure caused by internal over-pressure are avoided by a combination of preventive measures and dedicated systems. At the example of the EPRTM, the paper gives an overview of the severe accident mitigation strategy and the related measures and systems of AREVAs current Gen 3+ reactors, with special focus on the function of the core melt stabilization system.
From 1984 to 1989, 47 children with relapsed, refractory, and/or metastasized neuroblastoma were treated with 131 l‐metaiodobenzylguanidine (mlBG) in several different treatment combinations. At initial diagnosis, 36 children had Evans stage IV and 11 stage III disease. In 16 of the 47 children, tumor recurred after complete remission prior to mlBG treatment, 26 of 47 progressed from residual or nonresponding tumor, and in 5 of 47 tumor progression during chemotherapy was observed. Altogether the children were treated with a total of 112 courses (range 1–6) with a mean dosage of 8.9 ± 6.7 mCi/kg body weight/treatment course. Total dose was 283.2 ± 203.7 mCi for stage III and 388.9 ± 218.6 mCi for stage IV. Nine of 47 children reached a complete or a very good partial remission (CR and VGPR) from mlBG treatment alone, 13 of 47 achieved partial remission (PR). In an early analysis, 10 patients treated with mlBG in the neuroblastoma trial NB 85 of the German Society of Pediatric Oncology showed no significant difference in survival time compared with 30 conventionally treated children. However, the recent therapy series has been done with higher doses of mlBG, and during improved therapeutic scanning many more bone lesions could be detected than during earlier diagnostic scanning. We conclude that mlBG treatment has not yet fulfilled the expectations for it but still seems for certain indications to be a promising tool to treat neuroblastoma in the future. Moreover, the frontier of neuroblastoma detection is still advancing.
