Radiation Protection and Nuclear Safety is a basic skill for a nuclear engineer all over the world The course will provide knowledge of the fundamental topics involved in the radiation protection and safety analysis of nuclear plants (design basis and severe accidents) from both deterministic and numerical point of view. Main topics deal with natural and man-made sources of radiation, interaction of radiation with matter and biological effects, radiation sources in a nuclear reactor, radiation applications beyond energy production, shielding, detection and measurement techniques for radiation, assessment of environmental impact, including atmospheric dispersion of radionuclides and food chain contamination, nuclear accidents with case studies, protection against non-ionising radiation. The course will also deal with deterministic and probabilistic methodologies necessary to assess the safety of a nuclear power plant, with reference to both design basis and severe accidents. Both analytical models and numerical simulation tools will be provided and applied to study the fundamental thermal-hydraulic phenomena and system behaviour, that are fundamental to avoid the core damage during an accidental sequence.

The aim of the Course is to meet the needs of students at graduate level, to acquire knowledge and training in radiation protection and safety of nuclear plants. The course also aims to provide the necessary basic tools for those who will become professionals in radiation protection, safe use of radiation sources, nuclear safety analyses. It is designed to provide both theoretical and practical training in the multidisciplinary scientific and/or technical bases of national and international recommendations and standards on radiation protection and nuclear safety standards, and their implementation. At the end of the course the students should be able to analize and model the phenomena occurring during accidental transients, up to severe accidents, and the safety systems apt to the reduction of the risk to the population and environment.

Good knowledge of reactor physics, nuclear power plants and single and two-phase thermal-fluid-dynamics and heat transfer.

Radiation protection: Ionizing radiation and related physical quantities. Main sources of radiation: natural and artificial radionuclides, x-ray machines, nuclear reactors. Radiometric and dosimetric quantities. Fundamental physical dosimetry. Interaction of radiation with matter. Main phenomena, mechanisms of cell damage. Instrumentation for the detection of ionizing radiation. Legislation and regulations for radiation protection. Italian and international legislation. Radiation protection principles. Techniques for protection against ionizing radiation used to limit the exposure of workers and population. Shielding. Design of shielding required in the use of x-ray machines and radioactive sources of various kinds. Use of shielding codes. Environmental impact of radioactivity. Atmospheric dispersion and aquatic contamination in environmental matrices. Radiological Nuclear Safety. Nuclear accidents (Chernobyl, Fukushima, Mayak, etc..) and radiological events. Nuclear and radiological emergency management. Radiation protection of non-ionizing radiation (electromagnetic fields). Description, interaction with living matter, legislation, case studies. Safety of nuclear plants: Protection system and engineered safety features Deterministic analysis of Design Basis Accidents: causes, physical phenomena, simplified analytical models, characteristic time constants, time behaviour of process parameters during the accidents. Typical system codes for the thermal-hydraulic analysis Severe accidents: in-vessel and ex-vessel phenomena, fission product release from the reactor core and their removal from the containment system atmosphere. Typical system codes for severe accidents studies. Probabilistic Risk Assessment: objectives and results of the three levels of the PRA. development of event trees in PRA-Level 1 of nuclear reactors, containment failure modes, containment event tree. Safety problems in nuclear fusion reactors

The theoretical lectures are completed by two practical parts: Radiation protection: a practical part, dealing with the use of the radiation shielding code MICROSHIELD. After learning the use of the specified codes, the students will be divided into groups of maximum three people, and will be guided during the elaboration of a Case Report (CR), concerning a practical case (shielding calculations of a radioactive source). Safety of nuclear plants: a practical part dealing with numerical evaluations by the use of best estimate system codes for nuclear reactors by the thermal-hydraulics in advanced nuclear reactors components and in the PWR hot channel (with verification of the fuel rod limits). A research project (RP) will be the final result of this part (same grouping rules as above) The reports (CR and RP) will be evaluated and contribute to the final grade (see grading criteria). A visit to a radiation protection lab and learning of in-field use of instrumentation is part of the program.

Lecture notes on each topic will be provided online by the instructors. The following texts are recommended: ATTIX, F.H., Introduction to Radiological Physics and Radiation Dosimetry, Wiley, New York, (1986). CEMBER, H., Introduction to Health Physics, 3rd Edition, McGraw-Hill, New York (2000). FIRESTONE, R.B., BAGLIN, C.M., FRANK-CHU, S.Y. (Eds), Table of Isotopes (8th Edition, 1999 update), Wiley, New York (1999). KNOLL, G.T., Radiation Detection and Measurement, 3rd Edition, Wiley, New York (2000). R.A.Knief,"Nuclear Engineering", Hemisphere,1992. - P.B. Whalley, "Boiling, condensation and gas- liquid flow", Clarendon, Oxford, 1987 - John G. Collier, John R. Thome, Convective boiling and condensation, , 3rd ed., Clarendon, Oxford, 1996 - N.E.Todreas and M.S.Kazimi,"Nuclear systems",Vol.I ,II,Hemisphere,1990. - R.T.Lahey and F.J.Moody,"The thermal-hydraulics of a boiling water reactor",American Nuclear Society, New York, 1993. - L.S.Tong and J.Weisman,"Thermal analysis of pressurized water reactors",American Nuclear Society, La Grange Park,1996.

Slides;

Modalità di esame: Prova orale obbligatoria; Elaborato scritto prodotto in gruppo; Prova scritta in aula tramite PC con l'utilizzo della piattaforma di ateneo;

Exam: Compulsory oral exam; Group essay; Computer-based written test in class using POLITO platform;

... The exam is aimed at checking the student's knowledge about the topics listed in the official program of the course and his ability to apply the theory and the relative methods to answer questions dealing with Radiation Protection and Safety of Nuclear Plants. The exam consists of a written test with open-ended questions on the topics contained in the course program. It aims to verify the level of knowledge and understanding of the covered topics. In particular, it aims to verify the skills specified in the "Expected learning outcomes" part. The written exam deals with two parts, which the student may choose to address altogether or separately in any appeal. Part 1: two open-answer questions dealing with Radiation Protection. Time to answer: 60 minutes. Part 2: two open-answer questions dealing with Safety of Nuclear Plants. Time to answer: 60 minutes. Each part gets a grade going from 0 to 30. Each part is considered "pass" when the grade is equal or higher to 18/30. The two “pass” grades equally contribute (50%-50%) to the provisional final evaluation (a grade from 18 to 30), which will be completed with the evaluation of the Reports CR and RP (see Course Structure), to get the final grade. Each report may be evaluated as follows (in brackets the effect on the provisional final evaluation): Insufficient (must be edited until sufficient), sufficient (+0), good (+1). The exam is considered "pass" when the final grade is equal or higher to 18/30. During the written exam, it is not allowed to keep and consult books and notebooks. The results of the test are communicated on the portal, loading in the Materials section appropriate files with the grades), together with a date in which the students can participate to the oral discussion. The oral discussion deals with a collective review of the test results, followed by the possibility for each student of viewing his personal written elaborates, and ask questions, followed by a brief discussion of the reports CR and RP.

Gli studenti e le studentesse con disabilità o con Disturbi Specifici di Apprendimento (DSA), oltre alla segnalazione tramite procedura informatizzata, sono invitati a comunicare anche direttamente al/la docente titolare dell'insegnamento, con un preavviso non inferiore ad una settimana dall'avvio della sessione d'esame, gli strumenti compensativi concordati con l'Unità Special Needs, al fine di permettere al/la docente la declinazione più idonea in riferimento alla specifica tipologia di esame.