Rad Data Handbook 20.. - Voss Associates

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Shallow Dose Correction Factor In accordance with 10CFR20 and 10CFR835 deep dose equivalent shall be used for posting of radiation areas. Shallow dose equivalent shall be reported separate from deep dose equivalent. Deep dose equivalent is the sum of the gamma and neutron deep dose equivalents. Shallow dose includes low-energy photons and charged particles such as betas, positrons, and protons. Alpha particles are not included in shallow dose. The following applies to vented air ionization chambers with a window density thickness of 7 mg/cm 2 and a moveable shield with a density thickness of 1,000 mg/cm 2 . Determining the need to report a shallow dose; If the Open Shield Reading divided by the Closed Shield Reading is equal to or greater than 1.2, then perform a shallow dose survey. Calculate the shallow dose rate using this equation; (Open Shield Reading - Closed Shield Reading) x CF Obtain the CF (Correction Factor) from experimental or published data for the specific detector and radiation source(s). Typical correction factors for betas range between 2 and 5 (multipliers). Typical correction factors for low energy photons range between 0.1 and 1 (multipliers). Low energy photons that penetrate the closed shield of the ion chamber and produce a response in the instrument are part of the “deep” dose. Shallow Dose Correction Factor In accordance with 10CFR20 and 10CFR835 deep dose equivalent shall be used for posting of radiation areas. Shallow dose equivalent shall be reported separate from deep dose equivalent. Deep dose equivalent is the sum of the gamma and neutron deep dose equivalents. Shallow dose includes low-energy photons and charged particles such as betas, positrons, and protons. Alpha particles are not included in shallow dose. The following applies to vented air ionization chambers with a window density thickness of 7 mg/cm 2 and a moveable shield with a density thickness of 1,000 mg/cm 2 . Determining the need to report a shallow dose; If the Open Shield Reading divided by the Closed Shield Reading is equal to or greater than 1.2, then perform a shallow dose survey. Calculate the shallow dose rate using this equation; (Open Shield Reading - Closed Shield Reading) x CF Obtain the CF (Correction Factor) from experimental or published data for the specific detector and radiation source(s). Typical correction factors for betas range between 2 and 5 (multipliers). Typical correction factors for low energy photons range between 0.1 and 1 (multipliers). Low energy photons that penetrate the closed shield of the ion chamber and produce a response in the instrument are part of the “deep” dose. Shallow Dose Correction Factor In accordance with 10CFR20 and 10CFR835 deep dose equivalent shall be used for posting of radiation areas. Shallow dose equivalent shall be reported separate from deep dose equivalent. Deep dose equivalent is the sum of the gamma and neutron deep dose equivalents. Shallow dose includes low-energy photons and charged particles such as betas, positrons, and protons. Alpha particles are not included in shallow dose. The following applies to vented air ionization chambers with a window density thickness of 7 mg/cm 2 and a moveable shield with a density thickness of 1,000 mg/cm 2 . Determining the need to report a shallow dose; If the Open Shield Reading divided by the Closed Shield Reading is equal to or greater than 1.2, then perform a shallow dose survey. Calculate the shallow dose rate using this equation; (Open Shield Reading - Closed Shield Reading) x CF Obtain the CF (Correction Factor) from experimental or published data for the specific detector and radiation source(s). Typical correction factors for betas range between 2 and 5 (multipliers). Typical correction factors for low energy photons range between 0.1 and 1 (multipliers). Low energy photons that penetrate the closed shield of the ion chamber and produce a response in the instrument are part of the “deep” dose. Shallow Dose Correction Factor In accordance with 10CFR20 and 10CFR835 deep dose equivalent shall be used for posting of radiation areas. Shallow dose equivalent shall be reported separate from deep dose equivalent. Deep dose equivalent is the sum of the gamma and neutron deep dose equivalents. Shallow dose includes low-energy photons and charged particles such as betas, positrons, and protons. Alpha particles are not included in shallow dose. The following applies to vented air ionization chambers with a window density thickness of 7 mg/cm 2 and a moveable shield with a density thickness of 1,000 mg/cm 2 . Determining the need to report a shallow dose; If the Open Shield Reading divided by the Closed Shield Reading is equal to or greater than 1.2, then perform a shallow dose survey. Calculate the shallow dose rate using this equation; (Open Shield Reading - Closed Shield Reading) x CF Obtain the CF (Correction Factor) from experimental or published data for the specific detector and radiation source(s). Typical correction factors for betas range between 2 and 5 (multipliers). Typical correction factors for low energy photons range between 0.1 and 1 (multipliers). Low energy photons that penetrate the closed shield of the ion chamber and produce a response in the instrument are part of the “deep” dose.
NEUTRON SHIELD THICKNESS I = I0e -Nx where; I = final neutron flux rate I 0 = initial neutron flux rate = shield cross section in square centimeters N 3 = number of atoms per cm in the shield x = shield thickness in centimeters example: A dosimetry phantom is designed to simulate the composition of the human body. Ten % by weight is hydrogen. Assume a density of 1 and a shield cross section of hydrogen of 0.1 barns. A barn is 1E-24 2 3 cm . N, the number of atoms per cm , is 10% of Avogadro’s number, so N equals 6E22 hydrogen 3 atoms per cm . Assume the phantom thickness is 30 cm. 2 I 0 = 5,000 n/cm /s 2 = 1E-25 cm (0.1 barns) N = 6E22 atoms per cm 3 x = 30 centimeters thick -Nx = 1E-25 times 6E22 times 30 = -0.18 I = I0e -Nx 2 -0.18 I = 5,000 n/cm /s e 2 2 I = 5,000 n/cm /s x 0.835 = 4,175 n/cm /s The attenuation of the neutron flux by the phantom is about 16%. 59 NEUTRON SHIELD THICKNESS I = I0e -Nx where; I = final neutron flux rate I 0 = initial neutron flux rate = shield cross section in square centimeters N 3 = number of atoms per cm in the shield x = shield thickness in centimeters example: A dosimetry phantom is designed to simulate the composition of the human body. Ten % by weight is hydrogen. Assume a density of 1 and a shield cross section of hydrogen of 0.1 barns. A barn is 1E-24 2 3 cm . N, the number of atoms per cm , is 10% of Avogadro’s number, so N equals 6E22 hydrogen 3 atoms per cm . Assume the phantom thickness is 30 cm. 2 I 0 = 5,000 n/cm /s 2 = 1E-25 cm (0.1 barns) N = 6E22 atoms per cm 3 x = 30 centimeters thick -Nx = 1E-25 times 6E22 times 30 = -0.18 I = I0e -Nx 2 -0.18 I = 5,000 n/cm /s e 2 2 I = 5,000 n/cm /s x 0.835 = 4,175 n/cm /s The attenuation of the neutron flux by the phantom is about 16%. 59 NEUTRON SHIELD THICKNESS I = I0e -Nx where; I = final neutron flux rate I 0 = initial neutron flux rate = shield cross section in square centimeters N 3 = number of atoms per cm in the shield x = shield thickness in centimeters example: A dosimetry phantom is designed to simulate the composition of the human body. Ten % by weight is hydrogen. Assume a density of 1 and a shield cross section of hydrogen of 0.1 barns. A barn is 1E-24 2 3 cm . N, the number of atoms per cm , is 10% of Avogadro’s number, so N equals 6E22 hydrogen 3 atoms per cm . Assume the phantom thickness is 30 cm. 2 I 0 = 5,000 n/cm /s 2 = 1E-25 cm (0.1 barns) N = 6E22 atoms per cm 3 x = 30 centimeters thick -Nx = 1E-25 times 6E22 times 30 = -0.18 I = I0e -Nx 2 -0.18 I = 5,000 n/cm /s e 2 2 I = 5,000 n/cm /s x 0.835 = 4,175 n/cm /s The attenuation of the neutron flux by the phantom is about 16%. 59 NEUTRON SHIELD THICKNESS I = I0e -Nx where; I = final neutron flux rate I 0 = initial neutron flux rate = shield cross section in square centimeters N 3 = number of atoms per cm in the shield x = shield thickness in centimeters example: A dosimetry phantom is designed to simulate the composition of the human body. Ten % by weight is hydrogen. Assume a density of 1 and a shield cross section of hydrogen of 0.1 barns. A barn is 1E-24 2 3 cm . N, the number of atoms per cm , is 10% of Avogadro’s number, so N equals 6E22 hydrogen 3 atoms per cm . Assume the phantom thickness is 30 cm. 2 I 0 = 5,000 n/cm /s 2 = 1E-25 cm (0.1 barns) N = 6E22 atoms per cm 3 x = 30 centimeters thick -Nx = 1E-25 times 6E22 times 30 = -0.18 I = I0e -Nx 2 -0.18 I = 5,000 n/cm /s e 2 2 I = 5,000 n/cm /s x 0.835 = 4,175 n/cm /s The attenuation of the neutron flux by the phantom is about 16%. 59
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Abbreviations 115 Activity vs Expos
Page 3 and 4:
RADIOLOGICAL EMERGENCY RESPONSE Wri
Page 5 and 6:
HAZARD CONTROL PRIORITIES DURING ME
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ACUTE RADIATION EFFECTS 0 - 25 REM
Page 9 and 10: TABLE OF THE ELEMENTS Z Density Z D
Page 11 and 12: Relative Locations of Products of N
Page 13 and 14: RADIOACTIVE DECAY MODES OF COMMONLY
Page 15 and 16: Progeny kev and % abundance 55 Fe 5
Page 17 and 18: Progeny kev and % abundance 99 Mo 9
Page 19 and 20: Progeny kev and % abundance 208 Tl
Page 21 and 22: Progeny kev and % abundance 229 Th
Page 23 and 24: Progeny kev and % abundance 241 Am
Page 25 and 26: Progeny kev and % abundance Progeny
Page 27 and 28: Progeny kev and % abundance 222 Rn
Page 29 and 30: Neptunium Decay Chain (4n + 1) st 1
Page 31 and 32: Actinium Decay Chain (4n + 3) st 1
Page 33 and 34: Ci / g = 3.578E5 / (T 1/2 in years
Page 35 and 36: Rem/hr / Ci Sv/hr / GBq Half-Life C
Page 45 and 46: mRem/hr mSv/hr 1ì 10ì 100ì 1ì 1
Page 47 and 48: RADIATION BIOLOGY Maximum survivabl
Page 49 and 50: INTERNAL DOSIMETRY Calculating CDE
Page 51 and 52: EQUIVALENT DOSE, EFFECTIVE DOSE, an
Page 53 and 54: CALCULATING TODE AND TEDE TEDE = DD
Page 55 and 56: SHIELDING MATERIALS α a single she
Page 57 and 58: Beta Dose Rates in rad/hr per mCi M
Page 59: Combining Radiation Types to Determ
Page 63 and 64: Exposure Rate in an Air-Filled Ion
Page 65 and 66: Inverse Square Law 2 2 X 1 (D) 1 =
Page 67 and 68: Table 1 of DOE 5400.5 Surface Activ
Page 69 and 70: 6CEN The 6CEN equation can be used
Page 71 and 72: Ventilation Rates Ventilation rates
Page 73 and 74: AIR FLOW METER CORRECTIONS Mass Flo
Page 75 and 76: 10CFR20 DAC 10CFR835 DAC 10CFR20 AL
Page 103 and 104: External Exposure in a Cloud of Air
Page 105 and 106: Characteristic X-Rays (KeV) of the
Page 107 and 108: Z # K K L L 103 Lr 71 Lu 54.06 61.2
Page 109 and 110: COUNTING STATISTICS COUNTING STATIS
Page 111 and 112:
ELEVATION VS AIR PRESSURE Barometri
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NE Omaha 983 UT Cedar City 5,623 NH
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COMPOSITION OF AIR Density of Symbo
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ABBREVIATIONS ampere A, or amp angs
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Mass 1 gram = 0.03527 ounces 1 ounc
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Radiological 1 BTU = 235 1.28E-8 g
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CONSTANTS Avogadro's number (N 0) 6
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ELECTROMAGNETIC SPECTRUM Wavelength
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5. Air-proportional alpha detectors
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32 7. The bremsstrahlung from a 1 C
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RULES OF THUMB FOR NEUTRONS 1. The
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Spontaneous Fission Neutron and Gam
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Energy & Yield of neutrons from the
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WG Pu 15 years after fabrication 23
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Isotopic Mix of Natural U 238 U 234
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MISCELLANEOUS RULES OF THUMB 1. One
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PUBLIC RADIATION DOSES Average per
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COMPARATIVE RISKS OF RADIATION EXPO
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Voss Associates provides valuable t
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Publications Radiation Data Radiati
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Rad Data Handbook 20.. - Voss Associates

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