This standard specifies the general principles and basic requirements for estimating personal external exposure doses in radiation accidents. This standard applies to photon and neutron radiation external exposure accidents. This standard does not apply to beta radiation accidents. GBZ/T 151-2002 Principles for estimating personal external exposure doses in radiation accidents GBZ/T151-2002 Standard download decompression password: www.bzxz.net

ICS13.100
National Occupational Health Standard of the People's Republic of China GBZ/T151-2002
Principles of estimate on personal dose from external exposure in radiation accident Issued on April 8, 2002
Ministry of Health of the People's Republic of China
Implementation on June 1, 2002
This standard is formulated in accordance with the Law of the People's Republic of China on the Prevention and Control of Occupational Diseases. In case of any inconsistency between the original standard GB/T16135-1995 and this standard, this standard shall prevail. Appendices A, B, C and D of this standard are informative appendices. This standard is proposed and managed by the Ministry of Health.
Drafters of this standard: Li Kaibao, Zhao Zhaoluo Drafting unit of this standard: Institute of Radiation Protection and Nuclear Safety Medicine, Chinese Center for Disease Control and Prevention. The Ministry of Health is responsible for interpreting this standard.
1 Scope
Principles for estimating personal external exposure doses in radiation accidents GBZ/T151-2002
This standard specifies the general principles and basic requirements for estimating personal external exposure doses in radiation accidents. This standard applies to photon and neutron radiation external exposure accidents. This standard does not apply to beta radiation accidents.
2 Normative references
The clauses in the following documents become clauses of this standard through reference in this standard. For any dated referenced document, all subsequent amendments (excluding errata) or revised versions are not applicable to this standard. However, parties that reach an agreement based on this standard are encouraged to study whether the latest version of the document can be used. For any undated referenced document, its latest version applies to this standard. GBZ104
GBZ113
GBZ/T144
3 Terms and definitions
Diagnosis standard for acute radiation sickness caused by external exposure
Ionizing radiation accidents and medical treatment principles Dose conversion factors for radiation protection against external photon exposure The following terms and definitions apply to this standard. 3.1
Accidental exposureaccidentalexposure
Involuntary, unintentional exposure received in an accident situation. 3.2
External exposureexternalexposure
Irradiation of the human body by external radiation sources.
SingleacuteexposureA single high-dose exposure received in a short period of time. 3.4
FractatedexposureMultiple, intermittent exposures received over a longer period of time. 3.5
Protracted exposure
Continuous or intermittent exposure at a low dose rate over a long period of time. 3.6
Relatively uniform irradiation and non-uniform irradiation Under accidental exposure, the dose distribution in the body of the exposed person is often very uneven. When the variation factor of the absorbed dose value in different parts is not greater than 3, it can be called relatively uniform irradiation, and when it is greater than 3, it can be called non-uniform irradiation. 4 Preliminary identification of exposed persons
4.1 Determine whether they have been exposed to accidental exposure based on the description of the accident by the parties (or those present). 4.2 Whether a person has been exposed to accidental exposure should be identified based on the measurement results of personal dosimeters and site radiation monitoring devices, but attention must be paid to non-uniform and local irradiation to avoid misjudgment. 4.3 For relevant persons who may be exposed to neutrons, it should be identified whether they have been exposed to neutron radiation accidents based on the measurement results of the neutron-induced radioactivity of their blood, hair or metal products they carry. 4.4 Determine the degree of exposure based on the early symptoms of the exposed person, such as anorexia, nausea, vomiting and diarrhea, see GBZ104. 4.5 For those who are temporarily difficult to judge whether they have been exposed, it can be assumed that they have been exposed by the accident, and the identification will be made after the dosimetry data are obtained. 5 Accident dose estimation procedure
5.1 0~6h after the accident
5.1.1 Collect personal dosimeters and samples that can be used for accident dose measurement (such as watch rubies, etc.) for measurement, and check the records of radiation monitoring instruments on the scene when the accident occurred
5.1.2 If there is neutron exposure, collect hair, blood samples or metal products carried by relevant personnel for induced radioactive activity measurement.
Understand the accident process and exposure conditions, and ask the exposed person to simulate when the situation permits. 5.1.4 Collect blood samples to observe blood changes; culture lymphocytes to prepare for chromosome aberration analysis. 5.1.5 Make a preliminary estimate of the physical dose, and make a judgment on the uniformity of irradiation and the location of high-dose local irradiation. 5.2 7-71h after the accident
5.2.1 Review the data of the previous investigation and make further analysis. 5.2.2 If conditions permit and necessary, use a human model to simulate the accident exposure conditions and measure the dose distribution. 5.2.3 Compare the physical dose with the dose results inferred from the changes in blood picture. 5.2.4 Correct the preliminary results of the physical dose in the previous stage and provide preliminary dose distribution data. 5.3 72h after the accident
5.3.1 Compare the physical dose with the dose results estimated by chromosome aberration analysis and compare and analyze them with the clinical condition. Further accident simulation is carried out when necessary.
Provide a final report on the dose of the exposed person.
6 Accident investigation requirements
6.1 The on-site investigation should have a detailed investigation record, and audio and video recording should be carried out when necessary. 6.2 The investigation content includes the nature of the radiation source (radiation type, energy spectrum, etc.), source activity or radiation field exposure (or neutron flux) distribution, personnel exposure geometric conditions (distance, body position and posture), shielding and scattering conditions, exposure time and exposure method, etc. 6.3 The human body model used for simulation measurement should have the agreed geometric size and element composition, and the solid-state dosimeter used should have good tissue equivalence. If a tissue equivalent ionization chamber is used, its sensitive volume should be less than 1cm. Expression of accident dose
7.1 When evaluating random effects, the accident dose is expressed in effective dose equivalent. 7.2 When evaluating non-random effects, the accident dose is expressed in absorbed dose. 7.3 In both cases, the absorbed dose of the main organs (or tissues) should be given. 7.4 For non-uniform irradiation and fractionated and delayed irradiation, it should be normalized to the equivalent dose of a single exposure, see Appendix A and Appendix B. 8 Methods for measuring accidental doses
8.1 The peripheral blood lymphocyte chromosome aberration analysis technique can be used to determine the accidental dose of a relatively uniform irradiation, and the measurable dose range is about 0.25 to 5Gy.
8.2 For external irradiation accidents with a dose below 1Gy, the exposure dose of the exposed person can be estimated based on the early changes in his blood picture, see GBZ1138.3 The exposure dose at a local location can be measured using the exposed person's personal dosimeter or the material carried by the exposed person that can provide dosimetric information. The measurement results can be used as dose reference points to verify whether the established accident exposure conditions are reasonable. 8.4 The thermoluminescence phenomenon of watch rubies, etc. can be used to measure the local dose of the human body, and the measurable dose range is about 0.25 to 10Gy. 4
8.5 The dose can be measured by measuring the changes in the concentration of long-lived degrees of freedom generated by radiation in samples of certain accompanying items (such as drugs, etc.) of the exposed person using spin resonance spectroscopy technology, and the measurable dose range is about 0.5 to tens of Gy. 8.6 Neutron dose can be determined by neutron activation analysis of sodium in blood and sulfur in hair, and the measurable dose range is about 0.1 to tens of Gy.
9 Methods for estimating accidental doses
9.1 The general dosimetry method is mainly used to calculate the absorbed dose distribution in personnel, see Appendix C. 9.2 For the conversion of neutron irradiation from injection to absorbed dose, see Appendix D; for detailed data on the conversion of photon irradiation from irradiation or air kerma to dose equivalent, see GBZ/T144
10 Evaluation of dose estimation results
10.1 In the estimation of accidental dose, the most important parameters affecting the accuracy of physical dose are exposure time and distance, but their estimated values ​​are often affected by certain subjective factors. Therefore, it is generally difficult to make physical dose estimation accurate. 10.2 Under the condition of relatively uniform irradiation, chromosome aberration analysis technology can provide a relatively accurate overall dose average value, but for local, fractionated and delayed irradiation, dose evaluation is difficult. 10.3 The radiation dose is estimated by using the patient's early clinical response and blood picture changes. Due to the large individual differences, the dose results are semi-quantitative estimates.
10.4 The determination of the final dose should be based on physical dose, clinical observation and biological dose. 5
Appendix A
(Informative Appendix)
Method for calculating weighted equivalent dose of stem cell survivalA1 In the event of an accident, the radiation received by personnel is uneven. At present, there is no dose expression method that can be applied to various dose ranges and reflect the degree of effect to express this uneven radiation. This appendix uses the method of weighted equivalent dose of red bone marrow hematopoietic stem cells survival for reference to express the dose of bone marrow radiation patients. A2 Under non-uniform irradiation conditions, the calculation method for the survival rate (Sn) of stem cells is as follows: IeDmax
m(D)Su(D)dD
WwJDmir
Wherein: W—whole body red bone marrow mass, g;
D red bone marrow absorbed dose, Gy;
m(D) red bone marrow mass with an irradiated dose of D, g; Su(D)
-Stem cell survival rate when the dose is D under uniform irradiation conditions, %. The general expression of Su(D) is:
S,(D)=1-(1-eD/DO)
Wherein: Do—constant, Gy:
n constant.
（A2）
A3According to the data of red bone marrow distribution and dose distribution in the body, the stem cell survival rate S under non-uniform irradiation conditions is obtained according to equation (A1), and this is used as the stem cell survival rate under uniform irradiation conditions to substitute S, and substitute into equation (A2) to obtain D (i.e., stem cell survival weighted equivalent dose Dsw).
Appendix B
（Informative Appendix）
Method for normalizing fractionated and delayed irradiation to the equivalent dose of a single irradiation B1Fractured and delayed irradiation has a smaller radiation effect than a single equivalent dose of low-LET radiation. There is no mature method to normalize the cumulative dose of fractionated and delayed irradiation to the equivalent dose of a single irradiation. The calculation method proposed below is a calculation model commonly used in radiotherapy or an empirical formula summarized based on accident patient data, which can be used as a reference at this stage. The calculation formula for the equivalent dose NSD (nominal standard dose) of B2 fractionated irradiation is as follows: NSD = (TDF) 1/1.538
where: TDE
time-dose fractionation factor. The expression of TDF is as follows:
where: n
number of fractionated irradiation;
d fractionated irradiation dose, cGy:
TDF = n · d1538 . X-0.169
X interval between fractionated irradiation, days; (numerically X = 7/f, f is the frequency of fractionated irradiation per week (7 days).) Equation (B2) is applicable to n ≥ 4. In addition, TDF can be added, that is, K
TDFrolal=
where: TDF
is the time-dose fractionation factor of the first fractionation irradiation program, and the decay factor (decayfactor) is used to correct the rest between two courses. The calculation formula of the decay factor (DF) is as follows: DF= (T/(T+R)) 0.1
where: T——the treatment time interval of the first course, days; R——the time interval between the end of the first course and the beginning of the second course, days. For example, to calculate the equivalent dose after the end of two courses, the formula (B1) is corrected as follows; NSD= (TDF)) 1/1.538. DF+ (TDF2) V/1.538where: TDF
the TDF value of the first course;
the TDF value of the second course.
Calculation example: If n=10, d-100, cGy, X-1.4 days (5 irradiation sessions per week), calculate the equivalent dose of one irradiation. Calculation: (1) TDF=n·dl.538.X-0.169-10X1191X0.9447
-11252
(2) NSD= (TDF,) 1/1538
=(11252)/1.538
=430.6 (cGy equivalent)
The equivalent dose calculation formula for delayed irradiation is as follows: B3
ED=D/(1+K/V
Wherein: ED
equivalent to the irradiation dose equivalent within one week; cumulative dose, cGy;
D dose rate, cGy/min;
K is a constant, K=0.475 for normal healthy people, K=0.237 for leukopenia people. This formula is applicable to irradiation within 100 days. Appendix C
(Informative Appendix)|| tt||Calculation method of absorbed dose
C1 In the calculation of accidental dose, the calculation model used usually only considers the trunk, upper limbs and head and neck containing red bone marrow. In the calculation, the model is usually divided into 17 layers along the body axis (5 layers for the head and neck, 12 layers for the trunk). The location and number of each layer are shown in Table C1. Each calculation layer can be divided into several small three-dimensional units according to actual requirements. First calculate the dose of each unit, and then further calculate other doses to be considered.
Calculate the location of each layer.
Head center (forehead)
Orbit center
Oral center (nostril, tongue root, first 1st cervical vertebra) center of mandible (lower lip, 4th cervical vertebra)
7th cervical vertebra
Subclavian
2nd rib (middle of shoulder foot)
4th rib (center of sternum)
The calculation method of average absorbed dose is as follows: D
Where: D
Average absorbed dose, Gy:
D-absorbed dose in the ith small tissue block, Gym
The mass of the ith small tissue block, g. The calculation method of average dose of red bone marrow is as follows: C3
-Average dose of red bone marrow, Gy:
W-red bone marrow in the ith small cube Quantity, g.
The distribution of red bone marrow divided according to the above 17 sections is listed in Table C2. Table C2
Fifth rib (shoulder foot bone)
Subxiphoid
Seventh thoracic vertebra (ninth rib)
Second lumbar spine
Center of abdomen (umbilicus, third lumbar vertebra)
Upper end of armpit (fifth lumbar vertebra)
Center of pelvis (first vertebra)
Femoral head (upper edge of pubic symphysis)
Femoral trochanter
Distribution of red bone marrow!)
Note: 1) Under non-uniform irradiation conditions, the distribution of red bone marrow should be corrected for age, especially for children. 10
Appendix D
(Informative Appendix)
Neutron Fluence-Dose Conversion Factor
The data given in this appendix are used for the purpose of radiation protection. In the calculation, it is assumed that the anthropomorphic model is irradiated by a unidirectional wide beam (or a plane parallel beam). The irradiation geometry conditions are divided into forward (AP) irradiation, back (PA) irradiation, lateral (LAT) irradiation, rotational (ROT) irradiation and isotropic (ISO) irradiation. Table DI gives the effective dose equivalent of unit neutron dose of different energies under the above irradiation conditions.
D2 dose equivalent is limited to representing random effects produced in the low dose range and cannot be used to represent early acute damage to people caused by severe accident exposure (non-random effects). For the latter, the most basic radiation amount is the absorbed dose. Table D2 gives the absorbed dose of unit dose of different neutron energies at different tissue depths. The calculation model of these data is the equivalent uniform model of right cylindrical tissue, and it is assumed to be irradiated by a unidirectional parallel beam.
Neutron energy, Mev
2.5×10-8
1.0×10-7
1.0×10-6
1.0×10-5
1.0×10-4
1.0×10~ 3
1.0×10-2
2.0×10~2
5.0×10~2
1.0×10-1
2.0×10-1
5.0×10-1
Neutron fluence - Yes Conversion coefficient of effective dose equivalent AP
10-12svcm2
Neutron energy
1.0×10-7
1.0×10~6
1.0×10~5
1.0×10-+
1.0×10-3
1.0×10~2
5.0×10°
Conversion coefficient of neutron fluence-absorbed dose
Soft tissue depth,
10-Gy·cm2
.0.080080080080080080080(D)=1-(1-eD/DO)
Where: Do—constant, Gy:
n constant.
（A2）
A3According to the data of red bone marrow distribution and dose distribution in vivo, the stem cell survival rate S under non-uniform irradiation conditions is obtained according to equation (A1), and this is used as the stem cell survival rate under uniform irradiation conditions to substitute S, and substitute into equation (A2) to obtain D (i.e., stem cell survival weighted equivalent dose Dsw).
Appendix B
（Informative Appendix）
Method for normalizing fractionated and delayed irradiation to equivalent dose of one irradiation B1 Fractionated and delayed irradiation has a smaller radiation effect than one-time equivalent dose of low-LET radiation. There is no mature method to normalize the cumulative dose of fractionated and delayed irradiation to one-time equivalent dose. The calculation method proposed below is a calculation model commonly used in radiotherapy or an empirical formula summarized based on accident patient data, which can be used as a reference at this stage. The calculation formula for the equivalent dose NSD (nominal standard dose) of B2 fractionated irradiation is as follows: NSD = (TDF) 1/1.538
where: TDE
time-dose fractionation factor. The expression of TDF is as follows:
where: n
number of fractionated irradiation;
d fractionated irradiation dose, cGy:
TDF = n · d1538 . X-0.169
X interval between fractionated irradiation, days; (numerically X = 7/f, f is the frequency of fractionated irradiation per week (7 days).) Equation (B2) is applicable to n ≥ 4. In addition, TDF can be added, that is, K
TDFrolal=
where: TDF
is the time-dose fractionation factor of the first fractionation irradiation program, and the decay factor (decayfactor) is used to correct the rest between two courses. The calculation formula of the decay factor (DF) is as follows: DF= (T/(T+R)) 0.1
where: T——the treatment time interval of the first course, days; R——the time interval between the end of the first course and the beginning of the second course, days. For example, to calculate the equivalent dose after the end of two courses, the formula (B1) is corrected as follows; NSD= (TDF)) 1/1.538. DF+ (TDF2) V/1.538where: TDF
the TDF value of the first course;
the TDF value of the second course.
Calculation example: If n=10, d-100, cGy, X-1.4 days (5 irradiation sessions per week), calculate the equivalent dose of one irradiation. Calculation: (1) TDF=n·dl.538.X-0.169-10X1191X0.9447
-11252
(2) NSD= (TDF,) 1/1538
=(11252)/1.538
=430.6 (cGy equivalent)
The equivalent dose calculation formula for delayed irradiation is as follows: B3
ED=D/(1+K/V
Wherein: ED
equivalent to the irradiation dose equivalent within one week; cumulative dose, cGy;
D dose rate, cGy/min;
K is a constant, K=0.475 for normal healthy people, K=0.237 for leukopenia people. This formula is applicable to irradiation within 100 days. Appendix C
(Informative Appendix)|| tt||Calculation method of absorbed dose
C1 In the calculation of accidental dose, the calculation model used usually only considers the trunk, upper limbs and head and neck containing red bone marrow. In the calculation, the model is usually divided into 17 layers along the body axis (5 layers for the head and neck, 12 layers for the trunk). The location and number of each layer are shown in Table C1. Each calculation layer can be divided into several small three-dimensional units according to actual requirements. First calculate the dose of each unit, and then further calculate other doses to be considered.
Calculate the location of each layer.
Head center (forehead)
Orbit center
Oral center (nostril, tongue root, first 1st cervical vertebra) center of mandible (lower lip, 4th cervical vertebra)
7th cervical vertebra
Subclavian
2nd rib (middle of shoulder foot)
4th rib (center of sternum)
The calculation method of average absorbed dose is as follows: D
Where: D
Average absorbed dose, Gy:
D-absorbed dose in the ith small tissue block, Gym
The mass of the ith small tissue block, g. The calculation method of average dose of red bone marrow is as follows: C3
-Average dose of red bone marrow, Gy:
W-red bone marrow in the ith small cube Quantity, g.
The distribution of red bone marrow divided according to the above 17 sections is listed in Table C2. Table C2
Fifth rib (shoulder foot bone)
Subxiphoid
Seventh thoracic vertebra (ninth rib)
Second lumbar spine
Center of abdomen (umbilicus, third lumbar vertebra)
Upper end of armpit (fifth lumbar vertebra)
Center of pelvis (first vertebra)
Femoral head (upper edge of pubic symphysis)
Femoral trochanter
Distribution of red bone marrow!)
Note: 1) Under non-uniform irradiation conditions, the distribution of red bone marrow should be corrected for age, especially for children. 10
Appendix D
(Informative Appendix)
Neutron Fluence-Dose Conversion Factor
The data given in this appendix are used for the purpose of radiation protection. In the calculation, it is assumed that the anthropomorphic model is irradiated by a unidirectional wide beam (or a plane parallel beam). The irradiation geometry conditions are divided into forward (AP) irradiation, back (PA) irradiation, lateral (LAT) irradiation, rotational (ROT) irradiation and isotropic (ISO) irradiation. Table DI gives the effective dose equivalent of unit neutron dose of different energies under the above irradiation conditions.
D2 dose equivalent is limited to representing random effects produced in the low dose range and cannot be used to represent early acute damage to people caused by severe accident exposure (non-random effects). For the latter, the most basic radiation amount is the absorbed dose. Table D2 gives the absorbed dose of unit dose of different neutron energies at different tissue depths. The calculation model of these data is the equivalent uniform model of right cylindrical tissue, and it is assumed to be irradiated by a unidirectional parallel beam.
Neutron energy, Mev
2.5×10-8
1.0×10-7
1.0×10-6
1.0×10-5
1.0×10-4
1.0×10~ 3
1.0×10-2
2.0×10~2
5.0×10~2
1.0×10-1
2.0×10-1
5.0×10-1
Neutron fluence - Yes Conversion coefficient of effective dose equivalent AP
10-12svcm2
Neutron energy
1.0×10-7
1.0×10~6
1.0×10~5
1.0×10-+
1.0×10-3
1.0×10~2
5.0×10°
Conversion coefficient of neutron fluence-absorbed dose
Soft tissue depth,
10-Gy·cm2
.0.080(D)=1-(1-eD/DO)
Where: Do—constant, Gy:
n constant.
（A2）
A3According to the data of red bone marrow distribution and dose distribution in vivo, the stem cell survival rate S under non-uniform irradiation conditions is obtained according to equation (A1), and this is used as the stem cell survival rate under uniform irradiation conditions to substitute S, and substitute into equation (A2) to obtain D (i.e., stem cell survival weighted equivalent dose Dsw).
Appendix B
（Informative Appendix）
Method for normalizing fractionated and delayed irradiation to equivalent dose of one irradiation B1 Fractionated and delayed irradiation has a smaller radiation effect than one-time equivalent dose of low-LET radiation. There is no mature method to normalize the cumulative dose of fractionated and delayed irradiation to one-time equivalent dose. The calculation method proposed below is a calculation model commonly used in radiotherapy or an empirical formula summarized based on accident patient data, which can be used as a reference at this stage. The calculation formula for the equivalent dose NSD (nominal standard dose) of B2 fractionated irradiation is as follows: NSD = (TDF) 1/1.538
where: TDE
time-dose fractionation factor. The expression of TDF is as follows:
where: n
number of fractionated irradiation;
d fractionated irradiation dose, cGy:
TDF = n · d1538 . X-0.169
X interval between fractionated irradiation, days; (numerically X = 7/f, f is the frequency of fractionated irradiation per week (7 days).) Equation (B2) is applicable to n ≥ 4. In addition, TDF can be added, that is, K
TDFrolal=
where: TDF
is the time-dose fractionation factor of the first fractionation irradiation program, and the decay factor (decayfactor) is used to correct the rest between two courses. The calculation formula of the decay factor (DF) is as follows: DF= (T/(T+R)) 0.1
where: T——the treatment time interval of the first course, days; R——the time interval between the end of the first course and the beginning of the second course, days. For example, to calculate the equivalent dose after the end of two courses, the formula (B1) is corrected as follows; NSD= (TDF)) 1/1.538. DF+ (TDF2) V/1.538where: TDF
the TDF value of the first course;
the TDF value of the second course.
Calculation example: If n=10, d-100, cGy, X-1.4 days (5 irradiation sessions per week), calculate the equivalent dose of one irradiation. Calculation: (1) TDF=n·dl.538.X-0.169-10X1191X0.9447
-11252
(2) NSD= (TDF,) 1/1538
=(11252)/1.538
=430.6 (cGy equivalent)
The equivalent dose calculation formula for delayed irradiation is as follows: B3
ED=D/(1+K/V
Wherein: ED
equivalent to the irradiation dose equivalent within one week; cumulative dose, cGy;
D dose rate, cGy/min;
K is a constant, K=0.475 for normal healthy people, K=0.237 for leukopenia people. This formula is applicable to irradiation within 100 days. Appendix C
(Informative Appendix)|| tt||Calculation method of absorbed dose
C1 In the calculation of accidental dose, the calculation model used usually only considers the trunk, upper limbs and head and neck containing red bone marrow. In the calculation, the model is usually divided into 17 layers along the body axis (5 layers for the head and neck, 12 layers for the trunk). The location and number of each layer are shown in Table C1. Each calculation layer can be divided into several small three-dimensional units according to actual requirements. First calculate the dose of each unit, and then further calculate other doses to be considered.
Calculate the location of each layer.
Head center (forehead)
Orbit center
Oral center (nostril, tongue root, first 1st cervical vertebra) center of mandible (lower lip, 4th cervical vertebra)
7th cervical vertebra
Subclavian
2nd rib (middle of shoulder foot)
4th rib (center of sternum)
The calculation method of average absorbed dose is as follows: D
Where: D
Average absorbed dose, Gy:
D-absorbed dose in the ith small tissue block, Gym
The mass of the ith small tissue block, g. The calculation method of average dose of red bone marrow is as follows: C3
-Average dose of red bone marrow, Gy:
W-red bone marrow in the ith small cube Quantity, g.
The distribution of red bone marrow divided according to the above 17 sections is listed in Table C2. Table C2
Fifth rib (shoulder foot bone)
Subxiphoid
Seventh thoracic vertebra (ninth rib)
Second lumbar spine
Center of abdomen (umbilicus, third lumbar vertebra)
Upper end of armpit (fifth lumbar vertebra)
Center of pelvis (first vertebra)
Femoral head (upper edge of pubic symphysis)
Femoral trochanter
Distribution of red bone marrow!)
Note: 1) Under non-uniform irradiation conditions, the distribution of red bone marrow should be corrected for age, especially for children. 10
Appendix D
(Informative Appendix)
Neutron Fluence-Dose Conversion Factor
The data given in this appendix are used for the purpose of radiation protection. In the calculation, it is assumed that the anthropomorphic model is irradiated by a unidirectional wide beam (or a plane parallel beam). The irradiation geometry conditions are divided into forward (AP) irradiation, back (PA) irradiation, lateral (LAT) irradiation, rotational (ROT) irradiation and isotropic (ISO) irradiation. Table DI gives the effective dose equivalent of unit neutron dose of different energies under the above irradiation conditions.
D2 dose equivalent is limited to representing random effects produced in the low dose range and cannot be used to represent early acute damage to people caused by severe accident exposure (non-random effects). For the latter, the most basic radiation amount is the absorbed dose. Table D2 gives the absorbed dose of unit dose of different neutron energies at different tissue depths. The calculation model of these data is the equivalent uniform model of right cylindrical tissue, and it is assumed to be irradiated by a unidirectional parallel beam.
Neutron energy, Mev
2.5×10-8
1.0×10-7
1.0×10-6
1.0×10-5
1.0×10-4
1.0×10~ 3
1.0×10-2
2.0×10~2
5.0×10~2
1.0×10-1
2.0×10-1
5.0×10-1
Neutron fluence - Yes Conversion coefficient of effective dose equivalent AP
10-12svcm2
Neutron energy
1.0×10-7
1.0×10~6
1.0×10~5
1.0×10-+
1.0×10-3
1.0×10~2
5.0×10°
Conversion coefficient of neutron fluence-absorbed dose
Soft tissue depth,
10-Gy·cm2
.0.080538
Where: TDE
Time-dose fractionation factor. TDF is expressed as follows:
Where: n
Number of fractions;
d Fractional dose, cGy:
TDF=n · d1538 . X-0.169
X Fractional interval, days; (numerically X=7/f, f is the fractional frequency per week (7 days).) Equation (B2) is applicable when n≥4. In addition, TDF can be added, that is, K
TDFrolal=
where: TDF
is the time-dose fractionation factor of the first fractionation irradiation program, and the decay factor (decayfactor) is used to correct the rest between two courses. The calculation formula of the decay factor (DF) is as follows: DF= (T/(T+R)) 0.1
where: T——the treatment time interval of the first course, days; R——the time interval between the end of the first course and the beginning of the second course, days. For example, to calculate the equivalent dose after the end of two courses, the formula (B1) is corrected as follows; NSD= (TDF)) 1/1.538. DF+ (TDF2) V/1.538where: TDF
the TDF value of the first course;
the TDF value of the second course. bzxZ.net
Calculation example: If n=10, d-100, cGy, X-1.4 days (5 irradiation sessions per week), calculate the equivalent dose of one irradiation. Calculation: (1) TDF=n·dl.538.X-0.169-10X1191X0.9447
-11252
(2) NSD= (TDF,) 1/1538
=(11252)/1.538
=430.6 (cGy equivalent)
The equivalent dose calculation formula for delayed irradiation is as follows: B3
ED=D/(1+K/V
Wherein: ED
equivalent to the irradiation dose equivalent within one week; cumulative dose, cGy;
D dose rate, cGy/min;
K is a constant, K=0.475 for normal healthy people, K=0.237 for leukopenia people. This formula is applicable to irradiation within 100 days. Appendix C
(Informative Appendix)|| tt||Calculation method of absorbed dose
C1 In the calculation of accidental dose, the calculation model used usually only considers the trunk, upper limbs and head and neck containing red bone marrow. In the calculation, the model is usually divided into 17 layers along the body axis (5 layers for the head and neck, 12 layers for the trunk). The location and number of each layer are shown in Table C1. Each calculation layer can be divided into several small three-dimensional units according to actual requirements. First calculate the dose of each unit, and then further calculate other doses to be considered.
Calculate the location of each layer.
Head center (forehead)
Orbit center
Oral center (nostril, tongue root, first 1st cervical vertebra) center of mandible (lower lip, 4th cervical vertebra)
7th cervical vertebra
Subclavian
2nd rib (middle of shoulder foot)
4th rib (center of sternum)
The calculation method of average absorbed dose is as follows: D
Where: D
Average absorbed dose, Gy:
D-absorbed dose in the ith small tissue block, Gym
The mass of the ith small tissue block, g. The calculation method of average dose of red bone marrow is as follows: C3
-Average dose of red bone marrow, Gy:
W-red bone marrow in the ith small cube Quantity, g.
The distribution of red bone marrow divided according to the above 17 sections is listed in Table C2. Table C2
Fifth rib (shoulder foot bone)
Subxiphoid
Seventh thoracic vertebra (ninth rib)
Second lumbar spine
Center of abdomen (umbilicus, third lumbar vertebra)
Upper end of armpit (fifth lumbar vertebra)
Center of pelvis (first vertebra)
Femoral head (upper edge of pubic symphysis)
Femoral trochanter
Distribution of red bone marrow!)
Note: 1) Under non-uniform irradiation conditions, the distribution of red bone marrow should be corrected for age, especially for children. 10
Appendix D
(Informative Appendix)
Neutron Fluence-Dose Conversion Factor
The data given in this appendix are used for the purpose of radiation protection. In the calculation, it is assumed that the anthropomorphic model is irradiated by a unidirectional wide beam (or a plane parallel beam). The irradiation geometry conditions are divided into forward (AP) irradiation, back (PA) irradiation, lateral (LAT) irradiation, rotational (ROT) irradiation and isotropic (ISO) irradiation. Table DI gives the effective dose equivalent of unit neutron dose of different energies under the above irradiation conditions.
D2 dose equivalent is limited to representing random effects produced in the low dose range and cannot be used to represent early acute damage to people caused by severe accident exposure (non-random effects). For the latter, the most basic radiation amount is the absorbed dose. Table D2 gives the absorbed dose of unit dose of different neutron energies at different tissue depths. The calculation model of these data is the equivalent uniform model of right cylindrical tissue, and it is assumed to be irradiated by a unidirectional parallel beam.
Neutron energy, Mev
2.5×10-8
1.0×10-7
1.0×10-6
1.0×10-5
1.0×10-4
1.0×10~ 3
1.0×10-2
2.0×10~2
5.0×10~2
1.0×10-1
2.0×10-1
5.0×10-1
Neutron fluence - Yes Conversion coefficient of effective dose equivalent AP
10-12svcm2
Neutron energy
1.0×10-7
1.0×10~6
1.0×10~5
1.0×10-+
1.0×10-3
1.0×10~2
5.0×10°
Conversion coefficient of neutron fluence-absorbed dose
Soft tissue depth,
10-Gy·cm2
.0.080538
Where: TDE
Time-dose fractionation factor. TDF is expressed as follows:
Where: n
Number of fractions;
d Fractional dose, cGy:
TDF=n · d1538 . X-0.169
X Fractional interval, days; (numerically X=7/f, f is the fractional frequency per week (7 days).) Equation (B2) is applicable when n≥4. In addition, TDF can be added, that is, K
TDFrolal=
where: TDF
is the time-dose fractionation factor of the first fractionation irradiation program, and the decay factor (decayfactor) is used to correct the rest between two courses. The calculation formula of the decay factor (DF) is as follows: DF= (T/(T+R)) 0.1
where: T——the treatment time interval of the first course, days; R——the time interval between the end of the first course and the beginning of the second course, days. For example, to calculate the equivalent dose after the end of two courses, the formula (B1) is corrected as follows; NSD= (TDF)) 1/1.538. DF+ (TDF2) V/1.538where: TDF
the TDF value of the first course;
the TDF value of the second course.
Calculation example: If n=10, d-100, cGy, X-1.4 days (5 irradiation sessions per week), calculate the equivalent dose of one irradiation. Calculation: (1) TDF=n·dl.538.X-0.169-10X1191X0.9447
-11252
(2) NSD= (TDF,) 1/1538
=(11252)/1.538
=430.6 (cGy equivalent)
The equivalent dose calculation formula for delayed irradiation is as follows: B3
ED=D/(1+K/V
Wherein: ED
equivalent to the irradiation dose equivalent within one week; cumulative dose, cGy;
D dose rate, cGy/min;
K is a constant, K=0.475 for normal healthy people, K=0.237 for leukopenia people. This formula is applicable to irradiation within 100 days. Appendix C
(Informative Appendix)|| tt||Calculation method of absorbed dose
C1 In the calculation of accidental dose, the calculation model used usually only considers the trunk, upper limbs and head and neck containing red bone marrow. In the calculation, the model is usually divided into 17 layers along the body axis (5 layers for the head and neck, 12 layers for the trunk). The location and number of each layer are shown in Table C1. Each calculation layer can be divided into several small three-dimensional units according to actual requirements. First calculate the dose of each unit, and then further calculate other doses to be considered.
Calculate the location of each layer.
Head center (forehead)
Orbit center
Oral center (nostril, tongue root, first 1st cervical vertebra) center of mandible (lower lip, 4th cervical vertebra)
7th cervical vertebra
Subclavian
2nd rib (middle of shoulder foot)
4th rib (center of sternum)
The calculation method of average absorbed dose is as follows: D
Where: D
Average absorbed dose, Gy:
D-absorbed dose in the ith small tissue block, Gym
The mass of the ith small tissue block, g. The calculation method of average dose of red bone marrow is as follows: C3
-Average dose of red bone marrow, Gy:
W-red bone marrow in the ith small cube Quantity, g.
The distribution of red bone marrow divided according to the above 17 sections is listed in Table C2. Table C2
Fifth rib (shoulder foot bone)
Subxiphoid
Seventh thoracic vertebra (ninth rib)
Second lumbar spine
Center of abdomen (umbilicus, third lumbar vertebra)
Upper end of armpit (fifth lumbar vertebra)
Center of pelvis (first vertebra)
Femoral head (upper edge of pubic symphysis)
Femoral trochanter
Distribution of red bone marrow!)
Note: 1) Under non-uniform irradiation conditions, the distribution of red bone marrow should be corrected for age, especially for children. 10
Appendix D
(Informative Appendix)
Neutron Fluence-Dose Conversion Factor
The data given in this appendix are used for the purpose of radiation protection. In the calculation, it is assumed that the anthropomorphic model is irradiated by a unidirectional wide beam (or a plane parallel beam). The irradiation geometry conditions are divided into forward (AP) irradiation, back (PA) irradiation, lateral (LAT) irradiation, rotational (ROT) irradiation and isotropic (ISO) irradiation. Table DI gives the effective dose equivalent of unit neutron dose of different energies under the above irradiation conditions.
D2 dose equivalent is limited to representing random effects produced in the low dose range and cannot be used to represent early acute damage to people caused by severe accident exposure (non-random effects). For the latter, the most basic radiation amount is the absorbed dose. Table D2 gives the absorbed dose of unit dose of different neutron energies at different tissue depths. The calculation model of these data is the equivalent uniform model of right cylindrical tissue, and it is assumed to be irradiated by a unidirectional parallel beam.
Neutron energy, Mev
2.5×10-8
1.0×10-7
1.0×10-6
1.0×10-5
1.0×10-4
1.0×10~ 3
1.0×10-2
2.0×10~2
5.0×10~2
1.0×10-1
2.0×10-1
5.0×10-1
Neutron fluence - Yes Conversion coefficient of effective dose equivalent AP
10-12svcm2
Neutron energy
1.0×10-7
1.0×10~6
1.0×10~5
1.0×10-+
1.0×10-3
1.0×10~2
5.0×10°
Conversion coefficient of neutron fluence-absorbed dose
Soft tissue depth,
10-Gy·cm2
.0.080237. This formula is applicable to exposure within 100 days. Appendix C
(Informative Appendix)
Calculation method of absorbed dose
C1 In the calculation of accidental dose, the calculation model used usually only considers the trunk, upper limbs and head and neck containing red bone marrow. In the calculation, the model is usually divided into 17 layers along the body axis (5 layers in the head and neck, 12 layers in the trunk). The location and number of each layer are shown in Table C1. Each calculation layer can be divided into several small three-dimensional units according to actual requirements. First calculate the dose of each unit, and then further calculate the other doses considered.
Calculate the location of each layer.
Head center (forehead)
Orbit center
Oral cavity center (nostril, tongue root, first cervical vertebra) Mandibular center (lower lip, fourth cervical vertebra)
Seventh cervical vertebra
Subclavian
Second rib (middle of shoulder foot)
Fourth rib (sternum center)
The average absorbed dose is calculated as follows: D
Where: D
Average absorbed dose, Gy:
D-absorbed dose in the ith small tissue block, Gym
The mass of the ith small tissue block, g.
The average dose of red bone marrow is calculated as follows: C3 organ
-Average dose of red bone marrow, Gy:
W-mass of red bone marrow in the ith small cube, g. The distribution of red bone marrow according to the above 17 sections is listed in Table C2. Table C2
Fifth rib (shoulder foot bone)
Subxiphoid
Seventh thoracic vertebra (ninth rib)
Second lumbar spine
Center of abdomen (umbilicus, third lumbar vertebra)
Upper end of armpit (fifth lumbar vertebra)
Center of pelvis (first vertebra)
Head of femur (upper edge of pubic symphysis)
Trophorus of femur
Distribution of red bone marrow!)
Note: 1) Under non-uniform irradiation conditions, the distribution of red bone marrow should be corrected for age, especially for children. 10
Appendix D
(Informative Appendix)
Neutron Fluence-Dose Conversion Factor
The data given in this appendix are used for the purpose of radiation protection. In the calculation, it is assumed that the anthropomorphic model is irradiated by a unidirectional wide beam (or a plane parallel beam). The irradiation geometry conditions are divided into forward (AP) irradiation, back (PA) irradiation, lateral (LAT) irradiation, rotational (ROT) irradiation and isotropic (ISO) irradiation. Table DI gives the effective dose equivalent of unit neutron dose of different energies under the above irradiation conditions.
D2 dose equivalent is limited to representing random effects produced in the low dose range and cannot be used to represent early acute damage to people caused by severe accident exposure (non-random effects). For the latter, the most basic radiation amount is the absorbed dose. Table D2 gives the absorbed dose of unit dose of different neutron energies at different tissue depths. The calculation model of these data is the equivalent uniform model of right cylindrical tissue, and it is assumed to be irradiated by a unidirectional parallel beam.
Neutron energy, Mev
2.5×10-8
1.0×10-7
1.0×10-6
1.0×10-5
1.0×10-4
1.0×10~ 3
1.0×10-2
2.0×10~2
5.0×10~2
1.0×10-1
2.0×10-1
5.0×10-1
Neutron fluence - Yes Conversion coefficient of effective dose equivalent AP
10-12svcm2
Neutron energy
1.0×10-7
1.0×10~6
1.0×10~5
1.0×10-+
1.0×10-3
1.0×10~2
5.0×10°
Conversion coefficient of neutron fluence-absorbed dose
Soft tissue depth,
10-Gy·cm2
.0.080237. This formula is applicable to exposure within 100 days. Appendix C
(Informative Appendix)
Calculation method of absorbed dose
C1 In the calculation of accidental dose, the calculation model used usually only considers the trunk, upper limbs and head and neck containing red bone marrow. In the calculation, the model is usually divided into 17 layers along the body axis (5 layers in the head and neck, 12 layers in the trunk). The location and number of each layer are shown in Table C1. Each calculation layer can be divided into several small three-dimensional units according to actual requirements. First calculate the dose of each unit, and then further calculate the other doses considered.
Calculate the location of each layer.
Head center (forehead)
Orbit center
Oral cavity center (nostril, tongue root, first cervical vertebra) Mandibular center (lower lip, fourth cervical vertebra)
Seventh cervical vertebra
Subclavian
Second rib (middle of shoulder foot)
Fourth rib (sternum center)
The average absorbed dose is calculated as follows: D
Where: D
Average absorbed dose, Gy:
D-absorbed dose in the ith small tissue block, Gym
The mass of the ith small tissue block, g.
The average dose of red bone marrow is calculated as follows: C3 organ
-Average dose of red bone marrow, Gy:
W-mass of red bone marrow in the ith small cube, g. The distribution of red bone marrow according to the above 17 sections is listed in Table C2. Table C2
Fifth rib (shoulder foot bone)
Subxiphoid
Seventh thoracic vertebra (ninth rib)
Second lumbar spine
Center of abdomen (umbilicus, third lumbar vertebra)
Upper end of armpit (fifth lumbar vertebra)
Center of pelvis (first vertebra)
Head of femur (upper edge of pubic symphysis)
Trophorus of femur
Distribution of red bone marrow!)
Note: 1) Under non-uniform irradiation conditions, the distribution of red bone marrow should be corrected for age, especially for children. 10
Appendix D
(Informative Appendix)
Neutron Fluence-Dose Conversion Factor
The data given in this appendix are used for the purpose of radiation protection. In the calculation, it is assumed that the anthropomorphic model is irradiated by a unidirectional wide beam (or a plane parallel beam). The irradiation geometry conditions are divided into forward (AP) irradiation, back (PA) irradiation, lateral (LAT) irradiation, rotational (ROT) irradiation and isotropic (ISO) irradiation. Table DI gives the effective dose equivalent of unit neutron dose of different energies under the above irradiation conditions.
D2 dose equivalent is limited to representing random effects produced in the low dose range and cannot be used to represent early acute damage to people caused by severe accident exposure (non-random effects). For the latter, the most basic radiation amount is the absorbed dose. Table D2 gives the absorbed dose of unit dose of different neutron energies at different tissue depths. The calculation model of these data is the equivalent uniform model of right cylindrical tissue, and it is assumed to be irradiated by a unidirectional parallel beam.
Neutron energy, Mev
2.5×10-8
1.0×10-7
1.0×10-6
1.0×10-5
1.0×10-4
1.0×10~ 3
1.0×10-2
2.0×10~2
5.0×10~2
1.0×10-1
2.0×10-1
5.0×10-1
Neutron fluence - Yes Conversion coefficient of effective dose equivalent AP
10-12svcm2
Neutron energy
1.0×10-7
1.0×10~6
1.0×10~5
1.0×10-+
1.0×10-3
1.0×10~2
5.0×10°
Conversion coefficient of neutron fluence-absorbed dose
Soft tissue depth,
10-Gy·cm2
.0.080
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.