Quiz, Physics & Chemistry

Transcription

1 Eight Sessions 1. Pressurized Water Reactor 2. Quiz, Thermodynamics & HTFF 3. Quiz, Physics & Chemistry 4. Exam #1, Electrical Concepts & Systems 5. Quiz, Materials Science 6. Quiz, Strength of Materials - Statics 7. Quiz, Engineering Disasters 8. Exam #2, Engineering Seminar, Education & Careers 1

2 The Atom Nucleus Electrons in Orbitals Not to scale! 2

3 Atom Nucleus Nucleons o Protons o Neutrons Electrons Positive Electrical Charge No Electrical Charge Negative Electrical Charge The mass of an electron is approximately of a proton. 3

4 What determines an Element? For example: Oxygen or Gold? Number of Protons in the Nucleus Oxygen Gold O Au 8 Protons 79 Protons Uranium U 92 Protons 4

5 Atomic Number Number of Protons Atomic Mass Total of Number of Nucleons = Protons + Neutrons Fe 26 Fe Fe 26 5

6 Chemical Reactions Only have to do with the electron shell Gaining electrons Giving electrons Sharing electrons Not the Nucleus! 6

7 Electrical Charge of an atom Neutral: # of electrons = # of protons If lose an electron +1 charge If lose two electrons +2 charge If gain an electron: -1 charge

8 Ion An atom with a net electrical charge. Due to having less or more electrons than protons. Positive ions Negative ions 8

9 Periodic Table 9

10 Two atoms Isotope Two nuclei of the same element Always have the same number of protons But they can have different numbers of neutrons That makes them different isotopes of the same element Fe 10

11 What holds the nucleus together? Like Charges Repel Electro Static Force Strong Nuclear Force Attraction - Very close range 11

12 Some Isotopes are stable and some are radioactive Stable: No radioactive decay Radioactive decay alpha decay beta decay alpha particle beta particle 12

13 Line of Stability 13

14 Chart of the Nuclides 14

15 Reactor Physics Fission Process What happens to neutrons? Multiplication Factor Critical, Supercritical, Subcritical 15

16 Fuel in the Reactor Uranium: Atomic number 92 Natural Uranium mostly U U Best isotope for fission is U 235 Only about 0.7% in ore Must be enriched to about 3% or more 16

17 Pressurized Water Reactor Plant Secondary Plant Pzr G T S/G /G Rx Cond Primary Plant 17

18 Reactor 18

19 Top View of Reactor Core Coolant outlet Coolant inlet Fuel Assemblies 19

20 Fuel Assembly Fuel Rod Tubes Coolant Channels Control Rod Tubes 20

21 Fuel Fuel Pellets Rod Tube Fission Heat Coolant Flow 21

22 Conduction through Fuel Rod Tube Q K T T 2 T 1 22

23 Fission process and heat generation and transfer 23

24 U 235 Nucleus absorbs a neutron 24

25 Prompt Neutrons & Gammas 25

26 Fast Neutron Slowing Down H 2 O Moderator Thermal Neutron 26

27 Chain Reaction 27

28 Heat Deposition by fission fragments Kinetic Energy Electrostatic Fields Structural Atoms Vibrate more Region of higher temperature 28

29 29

30 Heat Transfer from Fuel Rod Tube Q K T T 2 T 1 Conduction Radiation Convection 30

31 Reactor Power neutrons U 235 fissions Heat output Leak Out Absorbed in non-fuel material 31

32 Prompt Neutrons Delayed Neutrons Slowing Down Moderator Thermal Neutrons Chain Reaction Neutron Flux 32

33 What happens to neutrons? Absorbed in Fuel Absorbed in non-fuel material Leak out 33

34 Neutron Population Generation to Generation Increasing? Decreasing? Staying the same? A reactor is a multiplying medium for neutrons. Multiplication Factor 34

35 Multiplication Factor, K k = k = Number of fissions in one generation Number of fissions in preceding generation Number of neutrons in one generation Number of neutrons in preceding generation 35

36 Multiplication Factor, K 100 neutrons in the core now. A chain reaction of fissions is in progress. After some cause fission, how many neutrons in the next generation? If K= x 1.0 = 100 neutrons Critical If K= x 1.1 = 110 neutrons Super-critical If K= x 0.9 = 90 neutrons Sub-critical 36

37 Multiplication Factor K>1 K=1 K<1 Fraction of neutrons absorbed in fuel, absorbed in non-fuel, leak out Supercritical, Critical, Subcritical 37

38 Muliplication Factor Depends on: Design Materials: Structural & Fuel Geometry: Shape and Size During Operation Control Rods Coolant Temperature 38

39 Control Rods Shim the Rods in More neutrons absorbed in the Control Rods Less neutrons to cause fission Multiplication factor goes down 39

40 Coolant Temperature Moderator Density Neutron Leakage Reactor 40

41 Neutron born Coolant Temperature Moderator Density Neutron Leakage Multiplication Factor goes up H 2 O Moderator Neutron Leaks out 41

42 Six Factor Formula k fl f L th Materials: Fuel & non-fuel Leakage 42

43 Multiplication Factor K>1 K=1 K<1 Fission rate Reactor Power Thermal Output Fraction of neutrons absorbed in fuel, absorbed in non-fuel, leak out Supercritical, Critical, Subcritical 43

44 Decay Heat 44

45 Chemistry Dissolve in water NaCl Atomic Masses: 23, 35 Molecular Weight= 23+35=58 45

46 H 2 O Na + Cl

47 Concentration [something]=10-4 Moles per liter 47

48 Concentration Molarity = gram-moles of solute per liter of solution Mole? Gram-Mole? 6.02 x Molecular Weight in Grams One Gram-Mole of NaCl = 58 grams 48

49 Self Ionization of Water Even in pure water 49

50 H 2 O Self Ionization of Water

51 Self Ionization of Water OH- H+ H 3 O+ Hydroxyl Hydrogen Ion Hydronium 51

52 Self Ionization of Water Concentration of OH - and H 3 O + in pure water 2H O H O 2 3 OH [OH - ]=10-7 [H 3 O + ]=10-7 Ionization Constant for water = [][]=

53 ph The negative log of hydronium ion concentration. 53

54 ph and poh ph log [ H 10 ] poh log [ OH 10 ] 54

55 Review of Logarithms log N b y b y N Take the logarithm of both sides 55

56 Review of Logarithms The logarithm of a number to a given base, is the power to which the base must be raised to produce the number. log N b y b y N 56

57 Review of Logarithms log 10 N y 10 y N Take the logarithm of both sides 57

58 ph and poh ph log [ H 10 ] poh log [ OH 10 ] 58

59 ph and poh Ionization Constant for water = [][]=10-14 ph + poh = 14 59

60 Acids and Bases Neutral Pure Water has ph of 7 [H 3 O + ]=10-7 Acids ph < 7 Bases ph > 7 60

61 Conductivity of water ph NaCl 61