ORAU Team

NIOSH Dose Reconstruction Project

Technical Basis Document for Portsmouth Gaseous Diffusion 

Plant – Occupational Medical Dose

Document Number:

ORAUT-TKBS-0015-3 

Effective Date: 07/19/2004

Revision No.: 01 

Controlled Copy No.: ________

Page 1 of 24

Subject Expert: Paul Demopoulos

Document Owner

Approval: Signature on File Date: 07/06/2004

Mark Notich, TBD Team Leader

Approval: Signature on File Date: 07/07/2004

Judson Kenoyer, Task 3 Manager

Concurrence: Signature on File Date: 07/07/2004

Richard E. Toohey, Project Director

Approval: Signature on File Date: 07/19/2004

James W. Neton, OCAS Health Science Administrator

Supersedes:

Revision No.: 00

TABLE OF CONTENTS

Section

ACRONYMS AND ABBREVIATIONS..................................................................................................

Page

4

3.0 OCCUPATIONAL MEDICAL DOSE............................................................................................5

3.1 EXAMINATION FREQUENCIES................................................................................................. 5

3.2 EQUIPMENT AND TECHNIQUES..............................................................................................6

3.2.1 Diagnostic x-ray Technique Generalizations 1954 to Date........................................... 11

3.2.1.1 Collimation.................................................................................................. 11

3.3 ORGAN DOSE CALCULATIONS ............................................................................................. 13

3.3.1 Photofluorography (1954-1960) ................................................................................... 13

3.3.2 Pre-1970 (1961-1969................................................................................................... 14

3.3.3 Type I Machine (1970-1978) ........................................................................................ 14

3.3.4 Type II Machine (1979-1989) ....................................................................................... 14

3.3.5 Type III machine (1990-present) .................................................................................. 15

3.4 UNCERTAINTY ........................................................................................................................16

3.5 DOSE RECONSTRUCTOR INSTRUCTIONS........................................................................... 17

3.5.1 Assignment of Organ Doses from X-ray Procedures: Approach for Dose 

Reconstructions ........................................................................................................... 17

REFERENCES..................................................................................................................................18

APPENDIX B OCCUPATIONAL MEDICAL DOSE ....................................................................... 20
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LIST OF TABLES

Table 3.1-1 Frequency of Occupational Chest X-rays at the PORTS......................................... 5

Table 3.2-1 Description of the X-ray Equipment Used at PORTS .............................................. 8

Table 3.2-2 Technique Factors Used for Each Type of X-ray Equipment................................... 9

Table 3.2-3 Medical x-ray Quality Assurance Parameters/PORTS ..........................................10

Table 3.2-4(d) Half Value Layer Limits.........................................................................................10

Table 3.2-5(e) Entrance Skin Exposure Limits .............................................................................10

Table 3.2.1-1a Relationship of Beam Intensity and Various Technical Factors.............................11

Table 3.3.1-1 Default Dose Values by Procedure .......................................................................13

Table 3.3.3-1 Default Dose Values by Procedure .......................................................................14

Table 3.3.5-1 Analogues for IREP Organs not Included in ICRP 34............................................15

Table B.1-1 Dose Equivalents for Organs Identified in ICRP 34 (1982) Beam Quality for P/A 

Views....................................................................................................................21

Table B.1-2 Dose Equivalent for IREP Organs not Included in ICRP 34 (1982) Beam 

Quality for P/A Views ............................................................................................22

Table B.1-3 Dose Equivalents for Organs Identified in ICRP 34 (1982) Beam Quality for 

LAT Views ............................................................................................................23

Table B.1-4 Dose Equivalent for IREP Organs not Included in ICRP 34 (1982) Beam 

Quality for LAT Views ...........................................................................................24
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RECORD OF ISSUE/REVISIONS

ISSUE 

AUTHORIZATION 

DATE

EFFECTIVE 

DATE

REV. 

NO. DESCRIPTION

Draft 10/03/2003 00-A New technical basis document for the Portsmouth 

Gaseous Diffusion Plant – Occupational Medical 

Dose. Initiated by Mark Notich. 

Draft 12/10/2003 00-B Incorporates comments from internal and NIOSH 

review. Initiated by Mark Notich.

01/05/2004 01/05/2004 00 First approved issue. Initiated by Mark Notich.

Draft 02/19/2004 01-A Approval rescinded due to additional NIOSH

comments. Incorporates comments to additional 

NIOSH comments. Initiated by Mark Notich.

Draft 05/26/2004 01-B Incorporates comments from internal and NIOSH 

reviews. Initiated by Mark Notich.

Draft 06/15/2004 01-C Incorporates additional comments from internal 

and NIOSH reviews. Initiated by Mark Notich.

07/19/2004 07/19/2004 01 Approved Issue of Revision 01. Initiated by Mark 

Notich.
Effective Date: 07/19/2004 Revision No. 01 Procedure No. ORAUT-TKBS-0015-3 Page 4 of 24

ACRONYMS AND ABBREVIATIONS

AAPM American Association of Physicists in Medicine

A/P Anterior Posterior (x-ray view)

Al Aluminum (x-ray machine filtration)

DEP Ohio State Department of Environmental Protection

DOE U.S. Department of Energy

ESE Entrance Skin Exposure

ESEG Entrance Skin Exposure Guideline

FDA/BRH Federal Drug Administration Bureau of Radiological Health

GAT Goodyear Atomic Corporation Technical Report

HVL Half Value Layer

ICRP International Commission of Radiation Protection

IREP Interagency Radiation Exposure Program

kVp Kilovolts Peak or peak kilovoltage

LAT Lateral (x-ray view)

mA Milliampere

mAs Milliampere seconds

mR MilliRoentgen 

NCRP National Council on Radiation Protection and Measurements

NIOSH National Institute for Occupational Safety and Health

P/A Posterior Anterior (x-ray view)

PORTS Portsmouth Gaseous Diffusion Plant

RMS root mean square

SID Source to Image Distance

SSD Source to Skin Distance

TBD Technical Basis Document

QA Quality Assurance
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3.0

The Portsmouth Gaseous Diffusion Plant (PORTS) required pre-employment physical examinations 

as part of their occupational health and safety program. These medical examinations typically 

included diagnostic chest x-rays. Medical x-rays during employment are offered every three years 

since 1989 but are not mandatory. The doses from these diagnostic x-ray procedures depended not 

only on the characteristics of the x-ray machine and the procedure used, but also on the frequency of 

the examination. Other types of x-rays such as lumbar, knee or ankle x-rays were given for on the job 

injuries at the discretion of the medical director but are not included in doses under EEOICPA. 

OCCUPATIONAL MEDICAL DOSE

Technical Basis Documents and Site Profile Documents are general working documents that provide 

guidance concerning the preparation of dose reconstructions at particular sites or categories of sites. 

They will be revised in the event additional relevant information is obtained about the affected site(s). 

These documents may be used to assist NIOSH in the completion of the individual work required for 

each dose reconstruction.

In this document the word “facility” is used as a general term for an area, building or group of buildings 

that served a specific purpose at a site. It does not necessarily connote an “atomic weapons 

employer facility” or a “ Department of Energy facility” as defined in the Energy Employee 

Occupational Illness Compensation Program Act of 2000 (42 U.S.C. § 7384l (5) and (12)).” 

3.1 EXAMINATION FREQUENCIES

X-ray examinations were conducted consistently for employees every three years from 1989 to 

present. Included in the medical procedures is the frequency of chest x-rays that were offered based 

upon worker age. Note asbestos and beryllium workers were required to have annual x-rays. After 

the pre-employment physical examination, chest x-rays were optional. This information may be 

recorded in the worker file provided by the U.S. Department of Energy (DOE). All occupational x-rays 

in the worker file are to be included in the reconstruction of occupational dose.

Table 3.1-1 lists the frequencies of chest x-rays for different age groups through the years and also 

identifies specific groups of workers. Declared pregnant women were not x-rayed from at least 1989. 

Typically one Posterior/Anterior (P/A) view was taken but Anterior/Posterior (A/P) and Lateral (LAT) 

view(s) were possible. 

Table 3.1-1 Frequency of Occupational Chest X-rays at the PORTS

Time period Frequency Comment

1954–1989(a) Annually All employees.

Annually Asbestos/Beryllium workers.

1990–2003 Offered Every 10 years Employees up to 30 years old.

Offered Every 5 years Employees up to and equal to 45 years old.

Offered Every 3 years Employees greater than 45 years old.

Annually Asbestos/Beryllium workers.

PORTS medical records include notations in individual worker files regarding both the date and the 

purpose of the of x-ray examinations. Included in some of the more recent records is the number of 

views. The current Medical X-ray technician stated the number of re-takes was virtually none. This is 

because the employees had shown concern about how many x-rays they were given, (1993 – 

present). The complex-wide x-ray guidance Technical Basis Document (TBD) indicate a 3 % re-take 
Effective Date: 07/19/2004 Revision No. 01 Procedure No. ORAUT-TKBS-0015-3 Page 6 of 24

rate based upon Trout et al (1973) in their analysis of the rejection rate of chest radiographs obtained 

during the Coal Mine “Black Lung” program reported an average rejection rate of 3% among 67,000 

radiographs. International Commission of Radiation Protection (ICRP) Publication-34 (ICRP-34) 

indicates a minimal value of 10 –12 % re-takes (ICRP 34, p 37). A 5 % re-take value will be used to 

be claimant favorable. 

Retakes should serve as a signal to give special consideration to the evaluation of technique factors, 

and hence the resultant dose calculations. A retake in a very large individual might serve as a signal 

that the initial radiograph was taken with technique factor settings suitable for a smaller person, and 

that the second radiograph reflected an additional and larger dose. 

About 80 % of the x-rays given were P/A chest x-rays. The others comprised of knee, hand, ankle 

legs and others mostly for injuries sustained at work. 

Specific organ doses to be attributed for P/A chest x-rays calculated on the basis of the dose 

conversion factors found in ICRP Publication 34 are given in Attachment B, Table B.1-1and B.1-2. 

LAT dose conversion factors are given in Attachment B, Table B.1-3 and B.1-4. For organs not listed 

in ICRP Publication 34 but specified in the Interagency Radiation Exposure Program (IREP) code, 

doses were determined by analogy with anatomical location (Table 3.3.5-1). Thus IREP code organs 

in the thoracic cavity, but not mentioned in the ICRP Publication 34 were assigned the same dose as 

the lungs; doses to the organs in the head and neck were assigned the same dose as the thyroid. 

The head and neck organ dose estimates (i.e. eye/brain), should be somewhat greater than doses 

actually incurred (hence claimant favorable), because of geometry considerations and at least in the 

case of the brain, because of attenuation by the bony cranium. To ensure claimant favorability in the 

view of the variations in organ dose described in ICRP Publication 34 (p. 51), the doses for females 

(lungs), which are slightly higher than those for males, were used. 

3.2 EQUIPMENT AND TECHNIQUES

Photofluorography

Chest photofluorography, which resulted in very much greater patient doses from a diagnostic 

procedure, was used sporadically until as late as the early 1960’s. Photofluorography used a smaller 

film (4 x 5 inches), a smaller source to skin distance (SSD) (42 inches), and both a higher peak 

kilovoltage (kVp) and typically a several fold greater exposure in terms of milliampere seconds (mAs). 

Exposure was regulated by photometers, which utilized the exposure to the film to determine the time 

of exposure. 

Even-though no evidence of the use of photofluorography was found at PORTS it is reasonable to 

presume that at least some of the occupational medical diagnostic chest x-rays with the DOE and its 

predecessor organizations were accomplished by photofluorography. The use of photofluorography 

should be assumed to ensure claimant favorable dose reconstructions from the time-period of 1954 

through 1960. 

Photofluorography differed from conventional radiography with film in that while kVp and milliampere 

(mA) settings could be manipulated by the technician, the exposure time was regulated by the amount 

of light generated in the photofluorographic unit, with a cutoff or maximum exposure time. An 

exposure of 15 mAs (150 mA for 0.1 second) was sufficient to produce a satisfactory image on 35 mm 

film (four by five inches); larger film required greater exposures (Sante 1954, p. 129). 
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Typical operating parameters reported for 1950’s photofluorography were 24 mAs at 83 kVp at a 

target to film distance of 36 inches (Braestrup 1958, p. 143), and 30 mAs at 90 kVp with a target to 

film distance of 40 inches and 2.4 mm added filtration. In the absence of data, a HVL of 2.5 mm 

should be assumed for dose determinations and is claimant favorable. Measurements at the Hanford 

site indicated that for a 60 mAs photofluorography exposure at 100 kVp, the entrance skin exposure 

(ESE) was 1.53 R (Rising and Soldat 1959), which is likely an upper limit value based on a large 

patient and is consistent with an ESE of about 600-700 milliroentgen (mR) for a 24-30 mAs exposure 

at somewhat lower kVp. The Hanford measured value of 1.53R ESE is likely an upper limit and 

hence an overstatement of the actual exposure from photofluorography to the average patient, and 

thus this 1.53R ESE value should be used in the absence of data to ensure claimant favorability. 
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Pre-1970

The x-ray machine information prior to 1970 is not available. The ESE was based upon the complexwide x-ray TBD guidance as presented in Table 3.3-1. Default Dose Values by Procedure presented 

in section 3.3-1. An air kerma of 200 mR for P/A and 500 mR for Lat x-rays was utilized in the organ 

dose calculations.

Type I (1970-1978)

The x-ray machine information from 1970 - 1978 is not available. The ESE was based upon the 

complex-wide x-ray TBD guidance as presented in Table 3.3.1-1. Default Dose Values by Procedure 

presented in section 3.3.1. An air kerma of 100 mR for P/A and 250 mR for Lat x-rays was utilized in 

the organ dose calculations.

Type II - III

The imaging system and generator have been the only changes since 1979. Currently in use is a GE 

MVP Micro x-ray 60 with a model COLL-C-150 x-ray tube. It can operate up to 150 kVp in a singlephase mode and up to 320 mA. ESE measurements do exist in some cases from the Ohio State 

Department of Environmental Protection (DEP), the Federal Drug Administration Bureau of 

Radiological Health (FDA/BRH) currently the Center for Devices and Radiological Health, and the 

Health Physics group at PORTS. However it is more claimant favorable to utilize the ESE values as 

calculated from the technique factors. 

Records concerning the medical x-ray equipment at PORTS from 1954 to 1979 were not located. A 

conversation with a physician that worked at the PORTS medical center within this time frame 

indicated that the employees went to three area hospitals for x-rays including the Southern Ohio 

Medical center during this time period for annual chest x-rays (Dr. Spears, conversation 9/18/03). 

A summary description of the x-ray equipment used at PORTS is included in Table 3.2-1. A summary 

of the specific technique factors for these machines is presented in Table 3.2-2. 

Table 3.2-1 Description of the X-ray Equipment Used at PORTS

Technique Time period Equipment

Photofluorography 

(PF)

1954-1960 No information available.

Pre-1970 1961-1969 No information available.

Type I 1970–1978 No information available. 

Type II 1979-1991 Hi-Speed Rare Earth Screens, Kodak X DMAT Model M-7B 

film Processor, GE MVP Micro x-ray 60 x-ray generator , GE 

Col C-150 x-ray Tube, Stationary 12:1 Grid, Film Processor, 

Manual timer, Manual techniques

Type III 1992–present Hi-Speed Rare Earth Screens, Kodak X DMAT Model M-7B 

film Processor, GE MVP Micro x-ray 60 x-ray generator , GE 

Col C-150 x-ray Tube (same as type II above), Stationary 

12:1 Grid, Film Processor, Automatic timer, Phototimed 

exposures
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Table 3.2-2 Technique Factors Used for Each Type of X-ray Equipment

Machine View

Current

(mA)

Voltage

(kVp)

Exposure time

(sec.)

Type I Techniques unknown. No records were kept with regard to the technique 

factors used during this time period. 

Type IIb P/Aa 200 110 1/10

Type IIIb P/A 200 110 1/10 

a. P/A indicates a P/A view, the average P/A chest measures 26 cm. The average Lat. chest measures 34 cm. 

b. Manual technique factors obtained from PORTS medical x-ray technologist.

Since no technique factors were identified by PORTS for Type I equipment, organ doses based on 

assumed technique factors were developed on the basis of x-ray techniques contemporary with the 

time period (i.e. 1970-1978) with due consideration given to claimant favorability. Accordingly, it was 

assumed that the operating kVp was 80, somewhat higher (and hence claimant favorable) than the 

kVp values typically used at the time (Morgan and Carrigan, 1955; Laughlin et. al. 1957). To offset 

this lower kVp, an increased exposure would be required as compared with Type II exposures, and 

this was conservatively taken to be 30 mAs, based on exposure time of 0.1 second at 300 mA. 

External filtration was assumed to be 1.5 mm Aluminum (Al) as compared with 2.5 mm Al used 

subsequent to 1979, which would further increase the dose. The SSD was assumed to be 152cm 

based on a Source to Image Distance (SID) of 183cm less a chest thickness of 26cm and an addition 

of 5cm to account for cassette thickness. {The Hanford TBD indicates a 79 mR ESE or 4 mR/mAs 

value for earlier era x-rays.} (ORAUT-TKBS-0003 TBD, 2003 and ORAUT-TKBS-0006-3 TBD 2003)

Some measurement results follow. As can be seen it would be more claimant favorable to utilize 

technique factor information for all x-ray machines. One result for ESE (PORTS HP department 

measurement) at a SID of 178 cm, 124 kVp, 250 mA, 0.013 sec yielded 6.0 mR exposure or 1.84 

mR/mAs. (PORTS HP x-ray Quality Assurance (QA) survey, 1988) A second result for ESE (FDA 

8/24/92 measurement) at a SID of 178 cm, 23 cm chest LucAl phantom, 120 kVp, 200 mA, and 0.1 

sec yielded a 12.8 mR exposure or a 0.64 mR/mAs. A third result for ESE (FDA 8/24/92) at a SID of 

178 cm, 23 cm chest LucAl phantom at 110 kVp, 320 mA, 0.083 sec yielded a 16.7 mR exposure or 

0.62mR/mAs.

The x-ray equipment currently in use has been QA checked for entrance skin exposure (ESE) by the 

manufacturer since 1979 and from the Health Physics group since 1985. Although all of the records 

for these QA checks on the x-ray equipment could not be found, the records available indicate that the 

x-ray equipment was working within FDA guidelines. American Association of Physicists in Medicine 

(AAPM) report number 4, “Basic Quality Control in Diagnostic Radiology” (1978), was followed to 

ensure Entrance Skin Exposure Guide (ESEG) was achieved. A diagnostic medical x-ray survey 

checking ESEG for different projection limits was followed. The QA of the x-ray machine included 

checks on the kVp, half value layer (HVL) determination for beam quality, exposure timing accuracy, 

beam collimation and alignment testing, and film-screen contact testing. Table 3.2-3 through Table 

3.2-5 summarizes the parameters tested and the allowed tolerances as stated in the PORTS 

procedure. (GAT S 39 1985)
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Table 3.2-3 Medical x-ray Quality Assurance Parameters/PORTS

kVp Requirements +/- 4 kVp (about 4%)

Timing Requirements t +/- 5 % for t > 10 msec and t +/- 20 % 

for t < 10 msec 

 

+/- 10% is used at PORTS no matter 

what the time.

Beam Alignment, Light and Radiation 

Field Congruence Requirements

less than 2% of the source to image 

distance (SID) or 2 cm.

The limits for HVL are as follows: 

Table 3.2-4(d) Half Value Layer Limits

Measured kVp Minimum HVL (mm Al)

50 1.3

60 1.3

70 1.5

80 2.3

90 2.5

100 2.7

110 3.0

120 3.2

130 3.5

140 3.8

150 4.1

d. GAT S 39 – “Medical x-ray Quality Assurance Tests AC 

Bassett – 1985, p 4

The ESE limits are as follows:

Table 3.2-5(e) Entrance Skin Exposure Limits

Projection ESEG (mR)

Chest (P/A) 30

Skull (Lat) 300

Abdomen (A/P) 750

Cervical Spine (A/P) 250

Thoracic Spine (A/P) 900

Full Spine (A/P) 300

Lumbo-Sacral Spine (A/P) 1000

Retrograde Pyelogram 

(A/P) 900

Feet (D/P) 270

e. GAT S 39 – “Medical x-ray Quality Assurance Tests AC 

Bassett – 1985, p 6
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From 1979 to 1994 a manual technique setting of 0.1 sec at 200 mA and 110 kVp was utilized for 

chest P/A views. (Communication with medical x-ray technologist.) After 1994 the exposures were 

photo-timed. To be more claimant favorable the manual techniques are utilized for Type I through 

Type III machines. 

X-ray organ dose estimates for occupational x-rays administered at PORTS are made for Type I 

equipment (used from 1970 through 1978), Type II equipment (used from 1979 to 1991), and Type III 

equipment (used from 1992 to the present). 

For the posterior/anterior view (P/A), a standard SID of 72 inches (183 cm) was used. Additional 

information indicated that all of the x-ray machines were single phase and that there was no air gap 

between the patient and the film. QA checks of the Type II and III machine indicated a 3.3 mm Al 

HVL. A value of 3.5 mm Al HVL would be claimant favorable for types II - III. Tables B-1 and B-2 list 

organ doses for P/A 14” x 17” chest films. 

For the LAT, 2.5 times the P/A entrance kerma value was used to estimate the LAT entrance kerma 

value. Tables B-3 and B-4 list organ doses for LAT 14” x 17” chest films. 

3.2.1

For convenience and possible application to cases in which the standard PORTS protocol was not 

followed, or for generic use, the effect of various technical factors has been tabulated below in Table 

3.2.1-1.

Diagnostic x-ray Technique Generalizations 1954 to Date 

Table 3.2.1-1a Relationship of Beam Intensity and Various Technical Factors

Parameter Units Relationship with Intensity

Applied voltage kVp Intensity proportional to 1.7 power of kVp

Tube current mA Linear

Exposure time s Linear

Filtration mm Al Intensity decreases by ~40% for each additional mm Al

Patient Size

(chest thickness) 

25-27 mm

> 27 mm

Dose increased by factor of 1.5

Dose increased by factor of 2

Distance d Approximately inverse square relations (1/d2)

Uncertainty +30 % Assume all errors are positive, + 30% should be used

Re-takes +5% Assume all workers had re-takes equal to 5% average

a. ORAUT-TKBS-0006-3 TBD 2003, p6

Air kerma was corrected for the thickness of the chest (26 cm) and for distance between the chest 

and the plane of the film (5 cm) to obtain the air kerma at skin entrance. The higher 3.5 mm Al 

filtration value was used since the dose conversion factors would be higher for 3.5 mm compared to 

lower values and thus more conservative and claimant favorable.

3.2.1.1 Collimation

Collimation refers to the size of beam. Early, the philosophy was to use a fairly large aperture (i.e. 

limited collimation) to ensure that the entire area of interest was included in the radiograph. 

Subsequently, because of patient protection concerns, beams were collimated such that the smallest 

beam consistent with the area of interest was used, thereby limiting the area of the patient exposed, 

and, in the case of chest radiography, minimizing dose to organs such as gonads, thyroid, and 
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gastrointestinal tract. Wochos et al. (1979) analyzed the 1972-1975 Nationwide Evaluation of X-Ray 

Trends (NEXT) data and found that at some facilities, primarily Internal Medicine and Medical GPs, 

the beam area to film area ratio could be as high as 2.0. 

In early years of operation (pre-1970), x-ray beam or scatter measurement data, techniques, or beam 

port information may not be available to estimate the collimation of the x-ray beam. Feldman et al. 

(1957) noted wide variation in their review of x-ray dose literature in 1957. Through measurements, 

Feldman et al. (1957) noted a factor of 10 increase in the gonadal dose when no external collimation 

was used. 

Due to the reported variation in the literature and measurement data on the effects of collimation, the 

claimant favorable assumption of no external collimation of the primary beam should be used when 

measurement data, technique, or other information to describe the collimation are not available for xrays taken prior to 1970. This is based on the following claimant favorable assumptions and 

professional judgment:

1. In the late 1950s, there was significant research into the gonadal dose and the reasons for the 

observed variation in dose. This research described the effects of filtration, collimation, and 

centering. By the early 1960s, techniques were being modified incorporating additional 

collimation. While these techniques were likely fully incorporated at most DOE facilities by 

1965, to allow for the possibility that some smaller facilities might not have had the resources 

to update their equipment and to be claimant favorable, the year 1970 was selected. 

2. In 1968, the National Council on Radiation Protection and Measurements (NCRP) in Report 33 

updated their guidance on medical x-ray protection. While many DOE facilities had probably 

already incorporated the guidance in this report, some smaller facilities might not have 

incorporated the guidance by 1968. To ensure that these facilities were in fact in conformance 

with the 1968 recommendations, an additional two-year period was added. 

3. By the late 1950s, reports in the literature of most of the surveys of medical x-ray facilities 

revealed low gonadal doses, indicating adequate collimation. A few surveys clearly indicated 

the use of collimation was limited. Of the eight surveyed facilities at Oak Ridge, only one 

(13%) had a moderately high male gonadal dose (5 mrad). All of the other facilities, the male 

gonadal dose was less than 2 mrad. Variation between the other facilities appeared to be the 

result of differences in the use of filtration and cone size. Since most facilities were using 

some form of collimation by the late 1950s, by the mid 1960s most, if not all, facilities were 

probably using some form of collimation. 

Since references as to when all facilities were using adequate collimation were not found, professional 

judgment was used to estimate this time-period to be the mid 1960s. To fully assure claimant 

favorability, this assumption has been further expanded by 5 years to 1970 to allow for the uncertainty 

in professional judgment. (ORAUT-OTIB-0006, section 2.4)

Review of the available documentation pertaining to the occupational medical program at PORTS 

from 1954 to the present revealed that only one diagnostic medical radiographic procedure was 

administered in connection with pre-employment or regular post-employment medical examinations, 

Posterior-anterior (P/A) 14” x 17” chest film. The LAT chest film was included in case records indicate 

their usage. Accordingly, only doses from these two techniques were evaluated. Any other 

radiographic examinations of PORTS employees that might have occurred were non-occupational in 

the sense that these were necessitated by illness or injury and hence not a part of the employee 
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physical examination process. Thus, there is no indication in the records that other diagnostic 

radiographic examinations were administered as a part of the occupational medical program.

3.3 ORGAN DOSE CALCULATIONS

ICRP Publication 34 (1982) provides tables of average absorbed dose (mGy) in selected organs for 

selected x-ray projections at 1 Gy entrance kerma (i.e., air kerma without backscatter), for selected 

views (including P/A), and for selected beam qualities (i.e., various HVLs). These tables provide the 

basic dose conversion factors for converting air kerma to organ dose. The average air kerma rates 

for the different machines are calculated using the cGy per mAs provided in NCRP No. 102, Table B.3 

(1989) for specific voltage, current, phase of the machine, and distance to the film. 

Finally, the PORTS organ doses are found by multiplying the ICRP 34 organ dose conversion factors 

by the entrance air kerma values. The resulting PORTS x-ray organ doses for all machines are in 

Tables B.01 through B.04. The doses are shown in units of dose equivalent or rem, assuming a 

quality factor of 1.0 for x-rays. PORTS records will indicate the view and in most cases only one view 

was taken per medical examination

3.3.1

Default values of entrance skin exposure have been developed for the three most commonly used 

occupational medical diagnostic x-ray procedures: P/A chest radiography; lateral chest radiography; 

photofluorographic chest films when actual measurement data or knowledge of technique factors are 

absent and minimal collimation is assumed. The default values are considered to be maxima 

developed from review of patient doses as reported in the literature, machine characteristics, and 

knowledge of x-ray procedures used during the time periods indicated. Sufficient conservatism was 

included in the determination of the default values to ensure with near certainty that the actual 

exposures from the specified procedures would not exceed the default values, thus ensuring claimant 

favorability. In determining these factors, it was assumed that a minimum of filtration was used along 

with low kilovoltage techniques, slow film speeds with standard development, and no additional 

collimation or use of cones. The default entrance kerma values for the three procedures are given in 

Table 3.3.1-1.

Photofluorography (1954-1960)

Table 3.3.1-1 Default Dose Values by Procedure 

Period Entrance kerma, cGy Entrance kerma, cGy Entrance kerma, cGy

P/A chest Lateral chest Photofluorographic chest

Pre-1970 0.20 0.50 3.0

The above default values can then be used as described above in lieu of actual measurement data or 

entrance kerma (ESE) derived from technique factors. These default ESE values were used in 

conjunction with uncollimated dose conversion factors as listed in the complex-wide x-ray TBD 

guidance document in Table 4.0-1 in ORAUT-OTIB-0006.

Organ doses for chest photofluorography are calculated in an analogous manner to organ doses 

calculated for conventional radiography using the ESE values. Table 4.0-1 provides dose conversion 

factors for the ICRP organs based on a distance of 152 cm and beam quality of 2.5 mm Al HVL. 
Effective Date: 07/19/2004 Revision No. 01 Procedure No. ORAUT-TKBS-0015-3 Page 14 of 24

3.3.2 

Prior to about 1970, x-ray measurement data, techniques, or beam port information may not be 

available to estimate the collimation of the x-ray beam. Several papers in the literature have 

considered the effects of cone size and centering on the organ dose, and concluded that filtration, 

kVp, and the smallest possible cone size were most important to reduce these doses (Feldman et al. 

1958). Due to the reported variation in the literature and measurement data on the effects of 

collimation, it is claimant favorable to assume minimal or no additional external collimation was used 

when measurement data, technique, or other information to describe the collimation are not available 

for x-ray procedures performed prior to 1970. 

Pre-1970 (1961-1969)

Without collimation, organs normally outside of the primary beam are exposed to the primary beam. 

This necessitates the use of dose conversion factors from ICRP 34 other than those for a P/A or lat 

chest x-ray, since ICRP 34 dose conversion factors are based on properly collimated beams. For 

uncollimated beams used prior to 1970, the uncollimated dose conversion factors as listed in the 

complex-wide x-ray TBD guidance document in Table 4.0-1 were used. The entrance kerma values 

for pre-1970 x-ray machine that are used in the organ dose calculations are listed in Table 3.3.1-1. 

The calculation is analogous to the organ doses calculated for conventional radiography as illustrated 

in section 3.3.4.

3.3.3

Default values as presented in Table 3.3.3-1 were obtained from the site wide x-ray medical dose 

technical basis document. The default values were determined from a review of patient doses as

reported in the literature, machine characteristics, and knowledge of x-ray procedures used during the 

time period indicated. In determining these factors it was assumed that a minimum of filtration was 

used along with low kilovoltage techniques, slow film speeds with standard development, and no 

additional collimation or use of cones (ORAUT-OTIB-0006 2003). An HVL of 2.5 mm was used in the 

organ dose calculations.

Type I Machine (1970-1978)

Table 3.3.3-1 Default Dose Values by Procedure 

Period Entrance kerma, cGy Entrance kerma, cGy

P/A chest Lateral chest

1970-1978 0.20 0.50

3.3.4

Based on the techniques in Table 3.2-2, the mAs for the types of equipment were calculated for each 

view:

Type II Machine (1979-1991)

Current (mA) × Exposure Time (sec) = Current for View (mAs) (3.3.4–1) 

Example for Type II P/A view: 200 mA × 1/10 s = 20 mAs 

The air kerma rate for 110 kVp was determined to be 0.25 cGy per 100 mAs (see Table B.3 of NCRP 

102) and the air kerma was calculated after converting the rate to air kerma per mA.

Current for View (mAs) × Corrected Air Kerma Rate (cGy/mAs) = Air Kerma (cGy) (3.3.4–2)

Example for Type II P/A view: 20 mAs × 0.0025 cGy/mAs = 0.05 cGy
Effective Date: 07/19/2004 Revision No. 01 Procedure No. ORAUT-TKBS-0015-3 Page 15 of 24

Multiply by 0.6 to account for 3.5 mm Al versus 2.5 mm Al Table B.3 NCRP 102 is based upon; 

{see Table 3.2.1-1 } 0.6 X .05 cGy = .030 cGy (3.3.4–3)

The air kerma was corrected for the thickness of the chest (26 cm) and for distance between the chest 

and the plane of the film (5 cm) to obtain the air kerma at skin entrance.

Air kerma at 183 cm x SID squared ÷ SSD squared = air kerma at skin entrance (3.3.4–4)

Example for Type II P/A view: 0.03 cGy x (183 cm)2 ÷ (152 cm)2 = 0.043 cGy

Air kerma at skin entrance was multiplied by the dose conversion factors in Table A.2 through A.8 of 

ICRP Publication 34 for P/A chest and HVL of 3.5 mm Al eq.

Air Kerma (cGy ) x Dose conversion factor = Dose for View (cGy) (3.3.4–5)

Example for Type II P/A view, dose to thyroid: 

0.043 cGy x 62 mGy/Gy x 1 Gy/100cGy x 1 rad/10 mGy = 2.67 E-3 rad

3.3.5

The survey measurements made by the FDA in 1992 which yielded 0.64 mR/mAs will be utilized to 

estimate the ESE. As indicated in table 3.2.1-1 a linear adjustment for mA is needed. The technique 

factor for time used was 0.1 seconds, and probably less because of the photo-timing system. The 

technique factor for kVp was 110 and for the current technique factor was 200 mA, the same 

parameters used for the FDA measurements therefore no adjustments are needed for these 

technique factors. All other parameters were the same. The ESE calculation adjustment based on the 

1992 FDA measurements is as follows:

Type III machine (1992-present)

0.64 mR/mAs x 0.1 sec x 200 mA = 12.80 mR 

Based on the techniques in Table 3.2-2, the mAs for the types of equipment were calculated for each 

view in the same manner as presented in section 3.3.4 above. Table 3.3.5-1 lists the reference organ 

used to approximate the organ analogue doses.

Table 3.3.5-1 Analogues for IREP Organs not Included in ICRP 34

Anatomical 

Location

ICRP 34 Reference 

Organ IREP Organ Analogues

Thorax Lung Thymus

Esophagus

Stomach

Bone surface

Liver/gall 

bladder/spleen

Remainder organs

Abdomen Ovaries Urinary/bladder

Colon/rectum

Uterus

Head and neck Thyroid Eye/brain
Effective Date: 07/19/2004 Revision No. 01 Procedure No. ORAUT-TKBS-0015-3 Page 16 of 24

3.4 UNCERTAINTY

Error, defined as deviation from the correct, true or conventionally accepted value of a quantity, and 

uncertainty, defined in terms of the potential range of a stated, measured, assumed or otherwise 

determined value of a quantity, provides an indication of the confidence of the dose estimates. Error 

implies knowledge of what the correct or actual value is, which is, of course, not known. Hence a 

more appropriate term is uncertainty, which is expressed in terms of a confidence level, e.g. 99% (i.e. 

that the correct or true value, although not actually known, has a 99% probability of falling within the 

range cited) and includes both precision or reproducibility of the measurement and accuracy, or how 

close the measurement or estimate of dose comes to the actual or correct value (ORAUT-TKBS-0003

2003, p5). 

Although in theory a large number of factors can introduce uncertainties or affect the x-ray machine 

output intensity and dose to the patient, in practice only four factors can be reasonably considered to 

have an impact on dose uncertainty. These are 1) variation in applied kilovoltage, 2) variation in 

beam current, 3) variation in exposure time, and 4) distance from the patient to the source of the X 

rays (SSD). The influence of such other factors as use of screens, grids, reciprocity failure, film speed 

and development, while potentially variable, would not affect the beam output intensity (ORAUTTKBS-0003 2003, p5).

For a given set of machine settings and parameters, x-ray output should theoretically be constant and 

unvarying. However, this is not true in practice; although output is essentially constant unless focal 

spot loading occurs such as might be the case when the power rating of the machine is exceeded. It 

is unlikely that power ratings were ever exceeded since so doing would be difficult to achieve in 

practice and would result in damage to the x-ray tube. However, even with the use of so-called 

constant voltage transformers to control line voltages, slight variations may occur in line voltage input 

or other internal voltages, which in turn could alter the kVp of the output beam. In general, for a given 

kVp setting, variation in kVp falls within ± 5% of the machine setting (Siebert et al. 1991). Since as 

noted above beam intensity is approximately proportional to the 1.7 power of the kilovoltage, this 

translates to an uncertainty of approximately ± 8.7%with respect to output beam intensity in the 80 to 

110 kVp range used for diagnostic radiographs at the PORTS Site . For conservatism, this is rounded 

up to ± 9% (ORAUT-TKBS-0003 2003, p 5 and ORAUT-TKBS-0006-3 2003, p 14).

Similarly slight variations in tube current are normal; as a tube ages, or heats up from usage, tube 

current may change and typically will drop. Hence, all other factors remaining constant, beam 

intensity will be reduced, and in direct proportion to the change in tube current. Typically, the 

reduction in beam output from current variation is not more than a few per cent under normal 

operating conditions; large decreases in beam output will be readily detected and result in 

maintenance on the machine to restore the output or, as a temporary stopgap measure, increase in 

the current or kVp to provide the necessary intensity for proper radiography. There is no evidence to 

suggest that these stopgap measures were ever necessary or applied at the PORTS Site. For a 

given kVp setting, output of the beam is a function of the tube current, which in turn is measured by a 

milli-ammeter on the machine and measures average tube current. The measurement is subject to 

uncertainties, and in addition there may be minor changes in output as the tube heats up from normal 

usage. These variations are typically small, and hence uncertainty in beam output attributable to 

current variation has been estimated at ± 5% (ORAUT-TKBS-0003 2003, p 6).

Another parameter that has potential to affect the dose, perhaps significantly, from a diagnostic 

radiograph relates to the time of exposure. This can be readily understood by noting that a full wave 

rectified machine produces 120 pulses per second of x-rays. For an exposure time of 1/20 of a 

second, only six pulses would result. A small error in the timer that resulted in a change of only ± 1 
Effective Date: 07/19/2004 Revision No. 01 Procedure No. ORAUT-TKBS-0015-3 Page 17 of 24

pulse would correspondingly affect the output by ± 17%; for an exposure time of 1/30 of a second, the 

change in output corresponding to a deviation of ±1 pulse is ± 25%. Early mechanical timers were 

notoriously inaccurate, although timer accuracy improved significantly with the introduction of 

electronic timers. PORTS timer was held to a +/- 10 % criteria from about 1979. However, once 

again for conservatism, uncertainty in beam output attributable to timers will be assumed to have an 

upper limit of + 25% (ORAUT-TKBS-0003 2003, p 6).

The final factor that is likely to affect patient dose relates to distance from the source of the x-rays, 

which is a determinant of the entrance skin exposure. For a given individual, the SSD will be 

determined largely by the thickness of the patient, and how accurate the positioning is. For a typical 

patient, this variation in SSD is estimated at no more than a few centimeters, with an upper limit of 

perhaps 7.5 cm. Using Inverse Square, this indicates an uncertainty of ± 10% from this source 

(ORAUT-TKBS-0003 2003, p 6).

There are two approaches to determination of the combined uncertainty from the above four potential 

sources of uncertainty. The first, and most conservative in that it gives the greatest range, would be 

to assume that the uncertainties are additive, which would give an uncertainty range of up to 9 + 5 + 

25 + 10 = 49. However, a more reasonable approach would be to assume that the uncertainties are 

in fact random, and to compute the statistical root mean square (RMS) value. The RMS value is 

simply the square root of the sum of the squares, and computes as ± 28.8%. Thus, for any individual 

entrance skin exposure (ESE) or derived organ dose, an uncertainty of ± 30 % l may be assumed; for 

further conservatism it may be appropriate to assume that errors are all positive, and only the + 30 % 

should be used (ORAUT-TKBS-0003 2003, p 6).

3.5 DOSE RECONSTRUCTOR INSTRUCTIONS

The information below provides instructions for dose reconstructors in determining organ doses from 

occupational medical (x-ray) procedures. For the purpose of evaluating probability of causation, x-ray 

doses are always considered acute, and are photons with energy E=30-250 keV.

3.5.1

Maximizing Medical X-ray Dose

Assignment of Organ Doses from X-ray Procedures: Approach for Dose 

Reconstructions

The organ doses assigned for each x-ray procedure are the highest doses to any organ in the 

relevant group as listed in Tables B1-B4 should be multiplied by a factor of 1.3 to account for 

uncertainty. The result will be the maximizing of annual x-ray doses that may be applied in dose 

reconstructions for likely non-compensable cases. At least one x-ray per year or partial year of 

employment should be assumed taken in order to be claimant favorable.
Effective Date: 07/19/2004 Revision No. 01 Procedure No. ORAUT-TKBS-0015-3 Page 18 of 24

REFERENCES

American Association of Physicists in Medicine (AAPM) report number 4, “Basic Quality Control in 

Diagnostic Radiology”, 1978 

A.C. Bassett, “Medical x-ray Quality Assurance Tests”, GAT S 39, 1/15/85 (1 – 41)

Braestrup, C. B. Radiation Protection. Charles C. Thomas, Springfield. 1958

Cardarelli, J., H. Spitz, C. Rice, R. Buncher, H. Elson and P. Succop. 2002. “Significance of 

Radiation Exposure From Work-Related Chest X-Rays for Epidemiological Studies of Radiation 

Workers”. Amer. J. Indust. Med. 42:490-501.

FDA Bureau of radiological health inspection dated 8/24/92.

Feldman, A., Babcock, G. C. Lanier, R. R., and Morkovin, D. 1958. “Gonadal Exposure Dose from 

Diagnostic X-ray Procedures”. Radiology 71:197-207.

GAT S 39, Bassett, A. C., “Medical x-ray Quality Assurance Tests”, 1985

International Commission on Radiological Protection. “Protection of the Patient in Diagnostic 

Radiology”. ICRP Publication 34. Annals of the ICRP. 9(2/3):1-82.

International Commission on Radiation Units and Measurements (ICRU). “Fundamental Quantities 

and Units for Ionizing Radiation”. ICRU Report 60. ” Bethesda: International Commission on

Radiation Units and Measurements (1998).

Laughlin, J. S., M. L. Muerk, I Pullman and R. S. Sherman. 1957. “Bone, Skin and Gonadal Doses in 

Routine Diagnostic Procedures. American Journal of Roentgenology, Radium Therapy and 

Nuclear Medicine 78:197-983

Morgan, R. H. and K. E. Corrigan, Eds. Handbook of Radiology. Chicago: The Year Book 

Publishers, Inc. (1955)

National Institute for Occupational Safety and Health NIOSH “External Dose Reconstruction 

Implementation Guideline”. OCAS-IG-001, rev 1, August 2002

National Council on Radiation Protection and Measurements (NCRP). “Medical X-Ray and GammaRay Protection for Energies Up To 10 MeV”. NCRP Report No. 33. Washington: National 

Council on Radiation Protection and Measurements (1968). 

National Council on Radiation Protection and Measurements (NCRP). “SI Units in Radiation 

Protection and Measurement”. NCRP Report No. 82. Bethesda: National Council on Radiation 

Protection and Measurements (1985).

National Council on Radiation Protection and Measurements (NCRP), “Medical x-ray, Electron Beam 

and Gamma-Ray Protection for Energies Up To 50 MeV”, NCRP Report 102. Bethesda (1989)
Effective Date: 07/19/2004 Revision No. 01 Procedure No. ORAUT-TKBS-0015-3 Page 19 of 24

ORAUT-OTIB-0006, “Dose Reconstruction from Occupationally Related Diagnostic x-ray 

Procedures”, Ronald L. Kathern, Vernon E. Shockley, Elyse M. Thomas and Timothy D. Taulbee, 

11/06/2003

ORAUT-TKBS-0003, “Technical Basis Document for the Savannah River Site to be used for 

EEOICPA Dose Reconstructions”, 8/21/2003

ORAUT-TKBS-0006-3, “Technical Basis Document for the Hanford Site – Occupational Medical 

Dose”, 9/16/2003

Portsmouth Health Physics Department X-ray QA survey, 1988 

Sante, L. R. Manual of Roentgenographic Technique. Ann Arbor: Edwards Brothers. 1946. p. 61

Seibert, J. A., G. T. Barnes and R. G. Gould. Specification, Acceptance testing, and Quality Control 

of Diagnostic x-ray Imaging Equipment. Medical Physics Monography No. 20. New York: 

American Institute of Physics. 1991.

Trout, E. D., Jacobson, G., Moore, R. T., and Shoub, E. P. 1973. “Analysis of the Rejection Rate of 

Chest Radiographs Obtained During the Coal Mine “Black Lung” Program”. Radiology 109:25-27.

Wochos, J. F., Detorie, N. A., and Cameron, J. R. 1979 “Patient Exposure from Diagnostic X-rays: An 

Analysis of 1972-1975 NEXT Data”. Health Physics 36:127-134.
Effective Date: 07/19/2004 Revision No. 01 Procedure No. ORAUT-TKBS-0015-3 Page 20 of 24

APPENDIX B OCCUPATIONAL MEDICAL DOSE

B.0 PORTS Medical X-ray

PORTS conducted pre-employment and annual physical examinations as part of their occupational 

health program. These examinations typically included a P/A chest x-ray. For some workers, and 

occupations, chest x-rays could be more frequent. 

B.1 Organ Doses from Medical x-rays

X-ray organ dose equivalents for occupational x-rays at PORTS are estimated for all years from 1954 

to present. The schedule for these exams for all PORTS employees over this time period is shown in 

Table B.1-1 through B.1-4, along with the organ dose information. Tables B.11 and B.1-2 are for P/A 

views for listed and unlisted organs in ICRP 34. X-ray organ dose estimates were made for 

photofluorography (1954-1960), per-1970 (1961-1969), Type I equipment (used from 1970 to 1978), 

Type II equipment (used from 1979 to 1991) and Type III equipment (used from 1992 to present). 

1 
Effective Date: 07/19/2004 Revision No. 01 Document No. ORAUT-TKBS-0015-3 Page 21 of 24

Table B.1-1 Dose Equivalents for Organs Identified in ICRP 34 (1982) for P/A Views

Time 

Period Frequency

PORTS 

Employee

Organ dose Equivalents per 14” x 17” P/A Chest (rem)

Air kerma 

at skin 

entrance(a) Thyroid(d) Ovaries(d) Testes(d) Lungs(d) Breast(d) 

Uterus(d) 

(Embryo)

Bone 

Marrow(d) 

1954-1960

(PFG)(b) Annual All

3.000

0.52 0.025 0.005 1.350 0.147 0.025 0.276

1961-1969

(Pre-1970)(c)

Annual All

0.200

minimal

collimation 0.0348 0.025 0.005 0.0902 0.0098 0.025 0.0184

1970-1978

(Type I) Annual All

0.100

2.5 mm HVL 0.0032 0.0001 0.000001 0.0451 0.0049 0.00013 0.0092

1979-1991 

(Type II) Annual All

0.043

3.5 mm HVL 0.00267 0.000138 0.00000043 0.0262 0.00391 0.000129 0.00628

1992-

present

(Type III)

Offered 

Every 10 

years

Employees up 

to 30 years old.

0.0128

3.5 mm HVL 0.000794 0.000041 0.000000128 0.00781 0.00116 0.0000384 0.00187

Offered 

Every 5 

years

Employees up 

to 45 years old.

Offered 

Every 3 

years

Employees 

greater than 45 

years old.

Annually Asbestos

/Beryllium 

workers.

(a) Air kerma at entrance skin in rem.

(b) Photofluorographic chest entrance uncollimated kerma (2.5 mm Al HVL) ORAUT-OTIB-0006, Table 4.0-1.

(c) Pre-1970 chest 99% confidence entrance uncollimated kerma (2.5 mm Al HVL) ORAUT-OTIB-0006, Table 4.0-1.

(d) Organs identified in ICRP 34 (1982) for dose determination from air kerma skin entrance dose equivalent associated with chest radiography.
Effective Date: 07/19/2004 Revision No. 01 Document No. ORAUT-TKBS-0015-3 Page 22 of 24

Table B.1-2 Dose Equivalent for IREP Organs not Included in ICRP 34 (1982) for P/A Views

Time 

period Frequency

PORTS 

employee

Organ dose Equivalents per P/A Chest (rem)

Air kerma ThymusEsophagus Stomach

Bone 

surface

Liver/gall 

bladder/

spleen

Urinary/ 

bladder

Colon/ 

rectum Eye/Brain Skin© Remainder

 1954-

1960

(PFG)(a) Annual All 3.000 1.35 1.35 1.35 1.35 1.35 0.025 0.025 0.096 4.05 1.35

1961-

1969

(Pre1970)(b) Annual All

0.200

minimal 

collimation 0.0902 0.0902 0.0902 0.0902 0.0902 0.025 0.025 0.0064 0.270 0.0902

1970-

1978

(Type I) Annual All

0.100

2.5 mm 

HVL 0.0451 0.0451 0.0451 0.0451

 

0.0451 0.0001 0.0001

 

0.0032 0.135 0.0451

1979- 

1991 

(Type II)

Annual All

 

0.043

3.5 mm

HVL

 

0.0262 0.0262 0.0262 0.0262

 

0.0262 0.000138 0.000138 0.00267 0.0602 0.0262

1992-

present

(Type 

III)

Offered 

Every 10 

years

Employees 

up to 30 

years old.

0.0128

3.5 mm 

HVL

0.00781 0.00781 0.00781 0.00781 0.00781 0.0000451 0.0000451 0.000794 0.0179 0.00781

Offered 

Every 5 

years

Employees 

up to 45 

years old.

Offered 

Every 3 

years

Employees 

greater 

than 45 

years old.

Annually Asbestos

/Beryllium 

workers.

(a) Photofluorographic chest entrance uncollimated kerma (2.5 mm Al HVL) ORAUT-OTIB-0006, Table 4.0-1 

(b) Pre-1970 chest 99% confidence entrance uncollimated kerma (2.5 mm Al HVL) ORAUT-OTIB-0006, Table 4.0-1 

(c) Entrance skin dose is entrance skin exposure calculated from air kerma, multiplied by a backscatter factor of 1.4 from NCRP 102, Table B-8.
Effective Date: 07/19/2004 Revision No. 01 Document No. ORAUT-TKBS-0015-3 Page 23 of 24

Table B.1-3 Dose Equivalents for Organs Identified in ICRP 34 (1982) Beam Quality for LAT Views

Time 

period Frequency

PORTS 

employee

Organ Dose Equivalents per LAT Chest (rem)

Air kerma 

at skin 

entrance(a) Thyroid(c) Ovaries(c) Testes(c) Lungs(c) Breast(c)

Uterus(c)

(Embryo)

Bone 

Marrow(c)

1961-1969

 (Pre1970)(a) Annual All0.500

uncollimated 0.0685 0.013 0.0025 0.1100 0.128 0.013 0.0185

1970-1978

(Type I) Annual All

0.250

2.5 mm HVL 0.0288 0.00015 0.000025 0.055 0.0638 0.00015 0.00925

1979-1991 

(Type II) Annual All

0.108

3.5 mm HVL 0.0162 0.000172 0.0000108 0.0333 0.034 0.000151 0.00656

1992-

present

(Type III)

Offered 

Every 10 

years

Employees up 

to 30 years old.

0.032

3.5 mm HVL 0.00483 0.0000512 0.0000032 0.00992 0.0101 0.0000448 0.00195

Offered 

Every 5 

years

Employees up 

to 45 years old.

Offered 

Every 3 

years

Employees 

greater than 45 

years old.

Annually Asbestos

/Beryllium 

workers.

(a) Air kerma at entrance skin in rem.

(b) Pre-1970 chest entrance uncollimated kerma (2.5 mm Al HVL) ORAUT-OTIB-0006, Table 4.0-1.

(c) Organs identified in ICRP 34 (1982) for dose determination from air kerma skin entrance dose equivalent associated with chest radiography.
Effective Date: 07/19/2004 Revision No. 01 Document No. ORAUT-TKBS-0015-3 Page 24 of 24

Table B.1-4 Dose Equivalent for IREP Organs not Included in ICRP 34 (1982) for LAT Views

Time 

period Frequency

PORTS 

employee

Organ Dose Equivalents per LAT Chest (rem)

Air kerma Thymus

Esophagus StomachBone 

surface

Liver/gall 

bladder/

spleen

Urinary/ 

bladder

Colon/ 

rectum

Eye/

Brain Skin (b)

Remainder

1961-1969

(Pre1970)(a) Annual All

0.500

uncollimated 0.110 0.110 0.110 0.110 0.110 0.013 0.013 0.0685 0.675 0.110

1970-1978

(Type I)

Annual All

0.250

2.5 mm 

HVL 0.055 0.055 0.055 0.055 0.055 0.00015 0.00015 0.0288 0.338 0.055

1979-1991 

(Type II)

Annual All

0.108

3.5 mm 

HVL 0.0333 0.0333 0.0333 0.0333 0.0333 0.000172 0.000172 0.0162 0.151 0.033

1992-

present

(Type III)

Offered 

Every 10 

years

Employees 

up to 30 

years old.

0.032

3.5 mm 

HVL

0.00992 0.00992 0.00992 0.00992 0.00992 0.0000512 0.0000512 0.00483 0.0479 0.00992

Offered 

Every 5 

years

Employees 

up to 45 

years old.

Offered 

Every 3 

years

Employees 

greater 

than 45 

years old.

Annually Asbestos

/Beryllium 

workers.

(a) Pre-1970 chest entrance uncollimated kerma (2.5 mm Al HVL) ORAUT-OTIB-0006, Table 4.0-1 

(b) Entrance skin dose is entrance skin exposure calculated from air kerma, multiplied by a backscatter factor of 1.4 from NCRP 102, Table B-8