Regulatory Guide 8.11
| ML003739450 | |
| Person / Time | |
|---|---|
| Issue date: | 06/30/1974 |
| From: | Office of Nuclear Regulatory Research |
| To: | |
| References | |
| RG-8.11 | |
| Download: ML003739450 (31) | |
June 1974 U.S. ATOMIC ENERGY COMMISSION
REGULATORY
DIRECTORATE OF REGULATORY STANDARDS
GUIDE
REGULATORY GUIDE 8.11 APPLICATIONS OF BIOASSAY FOR URANIUM
A. INTRODUCTION
DAC. It must be demonstrated that air sample results used for this purpose are representative of personnel Section 20.108, "Orders Requiring Furnishing of exposure.
Bioassay Services," of 10 CFR Part 20, "Standards for Protection Against Radiation," states that the Atomic 3. Under the minimum program, bioassays are per Energy Commission may incorporate in any license formed semiannually or annually for all workers to provisions requiring bioassay measurements as necessary monitor the accumulatiorý of uranium in the lung and or desirable to aid in determining the extent of an bone. More frequent bioassays are performed for a individual's exposure to concentrations of radioactive sample of the most highly exposed workers as a check material. As used by the Commission, the term bioassay on the air sampling program; these bioassays are per includes in vivo measurements as well as measurements formed at sufficient frequency to assure that a signifi of radioactive material in excreta. This guide provides cant single intake of uranium will be identified before criteria acceptable to the Regulatory staff for the biological elimination of the uranium renders the intake development and implementation of a bioassay program undetectable.
for mixtures of the naturally occurring isotopes of uranium U-234, U-235, and U-238. The guide is programmatic in nature and does not deal with labora 4. If a work area does not qualify for the minimum tory techniques and procedures. Uranium may enter the program, bioassays in addition to the minimum program body through inhalation or ingestion, by absorption are performed at increasingly higher frequencies, de through normal skin, and through lesions in the skin. pending on the magnitude of air sample results.
However, inhalation is by far the most prevalent mode of entry for occupational exposure. The bioassay pro 5. A model is used which correlates bioassay measure gram described in this guide is applicable to thi ment results with radiation .dose or with uptake of inhalation of uranium and its compounds, but does not uranium in the blood (chemical toxicity).
include the more highly transportable compounds UF
6 6. Actions are specified, depending upon the dose or and U0 2 F 2 .
uptake indicated by bioassay results. These actions are corrective in nature and are intended to ensure adequate Significant features of the bioassay program devel worker protection.
oped in this guidb ar listed below:
7. Guidance is referenced for the difficult task of
1. A bioassay program is necessary if air sampling is determining, from individual data rather than models, necessary for purposes of personnel protection. The extent of the bioassay the quantity of uranium in body organs, the rate of program is determined by the elimination, and the dose commitment.
magnitude of air sample results.
2. A work area qualifies for the "minimum bioassay This bioassay program encourages improvement in program" so long as the quarterly average of air sample the confinement of uranium and in air, sampling tech results is <1% of the Derived Air Concentration (DAC) niques by specifying bioassays only to-ihe extent that confinement and air sampling can not be entirely relied and the maximum used to obtain the average is <25% of upon for personnel protection.
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0. General
B. DISCUSSION
Maximum Permissible Annual Dose (MPAD) The annual maximum occupational radiation dose The topics treated in this guide include determining recommended by the ICRP for the body or part ul'
(1) whether bioassay procedures are necessary, (2) which the body.
bioassay techniques to use and how often, (3) who should participate, (4) the action to take as based on Maximum Permissible Dose Commitment (MPDc) I
bioassay results, and (5) the particular results which A dose commitment numerically equivalent to the should initiate such action. Taken together, these topics Maximum Permissible Annual Dose.
comprise an exposure control program. Technical bases for the criteria appearing in the guide are provided in Measurement Sensitivity Limit The smallest quan
"Applications of Bioassay for Uranium," WASH-1251, tity or concentration of radioactive material that which is available from the Superintendent of Docu can be measured with a specified degree of ments, U.S. Government Printing Office, Washington, accuracy and precision.
D.C. 20402.
Nontransportable- Slowly removed from the pul After an exposure to uranium has occuired, the monary region of the lung by gradual dissolution difficult problems of estimating the quantity present in .in extracellular fluids, or in particulate form by the body and the anticipated dose commitment arise. translocation to the GI tract, blood, or lymphatic This subject is treated in considerable detail in WASH system; Class (W), nontransportable dust with
1251. 50-day biological half-life in the lung. Class (Y),
nontransportable dust with 500-day biological
C. REGULATORY POSITION
half-life in the lung.
!. Special Terminology Transportable- Dissolved upon contact with extra cellular fluids and translocated to the blood- Class Several of the terms used in this guide have been (D), transportable dust with rapid clearance from given special definitions and are listed in this section for the lung.
the convenience of the reader.
Uptake -- The quantity of radioactive material enter Bioassay - The determination of the kind, quantity ing the nose and/or mouth during inhalation that or concentration, and location of radioactive is not exhaled and enters extracellular fluids.
material in the human body by direct (in vivo)
measurement or by analysis of materials excreted w/o U-235 Percentage by weight of the isotope or removed from the body. U-235 in a mixture of U--234, U-235, and U-238 (w/o U-235 in natural uranium is 0.72).
Derived Air Concentration (DAC) -- Equivalent to the concentrations listed in Appendix B to 10 2. Programmatic Guidance CFR Part 20.
The following programmatic guides are applicable Dowe Commitment (Dc) -- The total radiation dose where personnel are occupationally exposed to uranium equivalent to the body or specified part of the in respirable form and in sufficient quantity that body that will be received from an intake of measurements of uranium concentrations in air are radioactive material during the 50-year period considered to be necessary for the protection of workers following the intake. in ccmpliance with Regulatory requirements, including license conditions.
Exposure - The product of the average concentration of radioactive material in air and the period of time during which an individual was exposed to a. Basic Requirements and Minimum Capabilities that average concentration (jICi-hr/cc).
The following guides establish basic requirements Intake - The quantity of radioactive material and minimum capabilities which should he found in a entenng the nose and/or mouth during inhalation; program for protection against internal exposure from the product of the exposure and the breathing operations with uranium:
rate.
(1) Responsibilities foi protection against ura In Vivo Measurements - Measurement of gamma or nium contamination should be weil defined and under X-radiation emitted from radioactive material stood by all personnel concerned and should be specified located within the body, for the purpose of in direct;ves from management estimating the quantity of radioactive material (2) A comprehensive and technically sound protec present. tion program should be developed and implemented.
8.11-2 L
(3) Personnel, space, equipment, and support 3. Operational Guidance resources should be provided as necessary to conduct the program. a. Criteria for Determining the Need for a Bioasay
(4) An effective method of periodic internal audit Program of the protection program should be maintained.
(5) Before assigning employees to work in an area Where air sampling is required for purposes of where exposure to uranium contamination may occur, occupational exposure control, bioassay measurements action should be taken to ensure that facility and are also needed (Table 1) The bioassay frequency equipment safeguards necessary for adequate radiation should be determined by air sample results as averaged protection are present and operable, that the employees over I quarter.
are properly trained, that adequate procedures are prepared and approved, that an adequate surface and air Testing should be performed to determine whether contamination survey capability exists, that a bioassay awi sampling is representative of personnel exposures. Air program at least equivalent to the program described in sample results which have been verified as representative this guide will be maintained, and that survey and may be used to determine the quarterly average.
bioassay records will be kept.
If the 1-quarter average does not exceed 10% of b. Bioassay Program the appropriate Derived Air Concentration (DAC) from Appendix B to 10 CFR Part 20 and if the maximum In the development of a bioassay program the result used in the calculation of the average does not following guides should be implemented: exceed 25% of DAC, only a minimum bioassay program is necessary (Table 2). If the 1-quarter average exceeds
(1) Necessity 10% DAC, or if the maximum result exceeds 25% of the DAC, additional bioassays are necessary (Table 3),
The determination of the need for bioassay except as noted below. Frequency criteria for both cases measurements should be based on air contamination are discussed in Section C.3.c. The approach is illus monitoring results in accordance with criteria contained trated in Figure 1.
in this guide.
The additional bioassays are not performed for a
(2) Preparatory Evaluation specific individual if the licensee can demonstrate that the air sampling system used to protect the individual is Before assigning an employee to work in an adequate to detect any significant intake- and that area where substantial exposure to uranium contami procedures exist for diagnostic bioassays following nants may occur, his condition with respect to radio detection of an apparently large intake.
active material of similar chemical behavior previously deposited and retained in his body should be determined The necessity for bioassay measurements may also and the necessity for work restrictions evaluated. arise following an incident such as a fire, spill, equip ment malfunction, or other departure from normal
(3) Exposure Control operations which caused, or could have caused, abnor mally high concentrations of uranium An air. Criteria for The bioassay program should include, as appro determining this necessity are shown in Pigure 2. (The priate, capabilities for excreta analyses and in vivo term "Early Information" refers to an instrumented air measurements, made separately or in combination at a sampler with an alarm device.) Reliance cannot be sufficiently high frequency to assure that engineered placed on nasal swab results from mouth breathers.
confinement and air and surface contamination surveys bioassays should be performed.
are adequate for employee protection. The program should include all potentially exposed employees. Special bioassay measurements should be per formed to evaluate the effectiveness of respiratory
(4) Diagnostic Evaluation protection devices. If an individual wearing a respiratory protection device is subjected to a concentration of The bioassay program should include capabili transportable uranium in air within a period of I week, ties for excreta analyses and in vivo measurements as such that his exposure with no respiratory protection necessary to estimate the quantity of uranium deposited device would have exceeded 40 x DAC ,Ci-hr/cc, in the body and/or in affected organs and the rate of urinalysis should be performed to determine the result elimination from the body and/or affected organs. ing actual uranium uptake. If an individual wearing a
8.11-3
TABLE I
SELECTION OF BIOASSAY MEASUREMENT TECHNIOUES
Transportable Non transportable Purpose Compounds Compounds Choice of Measurement
1st 2nd' 3rd Preparatory Evaluationb uc ivc fr u Exposure Control Check on Air Sampling Program u iv f u Monitoring of Lung Burden Buildup - iv f u Monitoring of Bone Burden Buildup u u Detection of Unsuspected Intake u iv f Diagnostic Evaluation u iv f u Work Restriction Removal i iv f u alf for any reason air sampling is not adequately effective, and the appearance of urinary uranium is long delayed by extreme nontransportability, the buildup of uranium in the lung pmay continue undetected until a positive in vivo result is obtained. Fecal analysis is an excellent and highly recommended early indicator in such cases. Fecal analysis should be considered if in vivo measurements are too infrequent to permit early identification of an unfavorable trend.
bDiagnostic evaluation necessary if results are positive.
Cu, urinalysis; f, fecal analysis; iv. in vivo.
respiratory protection device is subjected to a concen would also aid in estimating the retention function and tration of nontranrsportable uranium in air within a dose commitment. Work restriction removal refers to period of 13 weeks, such that his exposure with no bioassays performed for employees who, because of past respiratory protection device would have exceeded depositions of radionuclides, have been restricted by
520 x DAC jiCi-hr/cc, the resulting actual uranium management in their work involving exposure to radio deposition in the lung should be determined using in active material until the magnitude of such depositions is vivo measurements and/or fecal analyses. These special reduced sufficiently to permit the removal of these work bioassay procedures should also be conducted if for any restrictions.
reason the magnitude of the exposure (with no respira tory protection device) is unknown. c. Selection of Measurement Frequency b. Selection of Measurement Techniques Acceptable frequencies for the minimum bioassay program are given in Table 24Table 3 gives acceptable The appropriate selection of bioassay techniques frequencies when additianal bioassay measurements are appears in Table 1. Preparatory evaluation refers to necessary to detect unsuspected single intakes, unless the bioassays performed for job applicants or existing measurement capability is the limiting factor. Figures 3 employees prior to an assignment involving potential through 7 present the maximum time between measure exposure to uranium. Exposure control refers to bio ments based on measurement sensitivity considerations;
assays performed to assure that engineered confinement the figures should be used to determine the measure and the air sampling program are sufficiently effective in ment frequency unless the interval specified in Table 3 is the control and evaluation of exposures. Diagnostic shorter. The Class (W) curve in Figure 5 may be used for evaluation refers to bioassays performed following a Class (Y) materials if it is known that Class (D) or Class known significant exposure. These evaluations are per (W) materials are present.
formed to determine the location and magnitude of uranium deposition, which would in turn aid in deter Table 2 specifies, for the minimum program, mining whether therapeutic procedures are indicated and semiannual or annual bioassays for monitoring the whether work restrictions are necessary. The evaluations accumulation of uranium in the lung and bone, plus
8.11-4
(
TABLE 2 BIOASSAY FREQUENCY FOR EXPOSURE CONTROL
Program Objective Dust Measurement Frequency Classification Techniquea Check on air sampling (D) u Use Figures 3 and 4 program and on con- (W) iv Use Figure 6 finement procedures (Y) iv Semiannual Minimum" and equipment.
Adequate if Monitor lung burden (W) iv AnnualF
QA < I/ I 0DA( buildup. (Y) iv Serruannualc and M < 1/4 DAC
Monitor bone burden (D) u Semiannual buildup. (W) u Semiannual (Y) u Class (D) or Class (W) Not Present, Annuald (Y) u Class (D) or Class (W) Present, Semiannuald Additional Detect unsuspected (D) u Use Table 3e
00 intake. (W) iv, f, or u Use Table 3 e Acceptable it (Y) iv, f. or u Use Table 3e QA > 1/10 DAC
and/or M > 1/4 DAC
aiv, n vivo; u, urinalysis; f, fecal analysis.
bQA, quarterly average of air sample results; M, maximum result used to determine QA
CThese frequencies are applicable if no individuals are near work restriction limits. Quarterly or even monthly iv may become necessary as workers approach these limits dSpecial urinalysis should be performed each time exposure to new Class (Y) material begins to determine if more transportable component is present.
eThese measurements are additional to those listed above for the minimum program. If it is demonstrated that air sampling provided for a specific individual is adequate to detect any sigmficant intake and that procedures exist for diagnostic bioassays following detection of an apparently large intake, these additional measurements need not be performed.
TABLE 3 FAEQUENCYa FOR ADDITIONAL BIOASSAYS BASED ON CONCENTRATION OR EXPOSURE
QA Most recent quarterly average of concentration or most recent quarterly average of weekly exposures M Maximum result used in the calculation of the quarterly average u urinalysis iv - it vivo Multiply numbers in first column by DAC pCi/cc or by 40 DAC pCi-hr/cc. Frequencies are given in bioassaysper year at equally spaced intervals.
Air Sample Results Class (D) Class(W) Class (Y)
u U iv ub iv O<QA< 1/10
1/4<M< I 2 1 2 I <M< 10 4 4 2 4 2
10<M 12 12 4 12 4 I/i0<QA< 1/4
0<M< I 2 1 4 I <M<10 4 4 2 12 4
10< M 12 12 4 26 4
1/4<QA< 1/2 C<M< I 4 2 4
2c
12 i<M< !0 4 12 4 26 4 ii < M 12 26 12 52 12
1i2<QA< I
0<M< 10 12 26 12 26 12
10<M 26 52 12 52 12 a Low frcqucncicý indicated may be precluded by measurement capability limitations: see Figures 3 through 7 bAppicable if Class (D) or Class (W) materials are known to be present;convert 52 and 26 to 12 if they are not present. Fecal analysis may be substituted for urinalysis.
c Frequency possible only for high w/o U-235; naturally occurring urinary uranium prohibits detection otherwise.
more frequent bioassays (based on measurement sensi who is protected by a monitoring system that essentially tivity) to check on the air sampling program. Section assures detection of any significant intake.
C.3.d indicates that all workers should participate in the bioassay program for purposes of monitoring the organ Although fecal analysis is not shown in Table 3, buildup, while only a sample of workers is sufficient for this procedure is preferred over urinalysis for Class (W)
checking the air sampling program. If a working area and Class (Y) materials and may be substituted for does not qualify for the minimum program, additional urinalysis in the table. If in vivo measurements are made bioassays are specified in Table 3 at somewhat higher at the frequency shown for urinalysis, Class (W) and frequencies. Any urinalysis procedure performed for one Class (Y), the unnalyses are unnecessary; the urinalyses of these purposes may be used to satisfy a urinalysis prescribed in Table 2 are adequate.
requirement for another purpose, provided the fre quency criteria are met. A similar statement may be The bioassay measurement frequency, as deter made regarding in vivo measurements. mined from Table 2 or 3 (or the associated figures),
should not be decreased because of consistently low The purpose of the additional bioassay measure bioassay results; bioassay measurements are needed as a ments is the timely detection of unsuspected exposures final check on the contamination confinement capability not detected by the air sampling program. Therefore, the and on the effectiveness of the air sampling program.
additional bioassays are not necessary for an individual Consistently high bioassay results may suggest that more
8.11-6
frequent bioassays should be performed even though A monthly in vivo frequency may be reduced to there is no such indication from air samples. In this case, quarterly if weekly fecal analyses are made, with an in however, improvements in the air sampling program are vivo measurement at the end of the quarter. An in vivo required rather than more frequent bioassays. The measurement should be performed as soon as practicable appropriate frequency can be determined from air if the excretion rate exceeds 7 pCi/day Class (Y) or 700
sample data if the air sampling program is adequately pCi/day Class (W). For lower results the following representative of inhalation exposures. procedure should be followed. Results from the first 4 weekly specimens should be plotted (semilog) against If workers are exposed to a mixture of uranium time, and a best fitting curve should be extrapolated to t compounds, the DAC for the mixture, DACm, should be = 0. thus obtaining an estimate of the initial excretion calculated as rate, (dP Idt)o, and the individual's half-lifel T. The dose commitment, Dc, should be estimated using these values
-I with the following equation:
DACm [i, Dn= f Zi DAC1
] Dc= 8.4 T2 [
where DACi is the DAC for the ith compound and fi is a fraction representing the contribution of the ith com where T is in days and (dP/dt)o is in MOCt/day. The pound. The calculation of fi depends on the exposure actions indicated in Table 4 should then be taken. This mode. If the material is a mixture, fi is the activity procedure should be repeated at the end of 8 weeks fraction. For exposure in more than one area, fi is the when results from 8 specimens are available. At the end time fraction spent in the ith area. As an alternative of the quarter D. should be evaluated using results from DACm may be taken as the lowest DACi. As to the all 12 specimens. If the indicated Dc is < 3 rems, the in quarterly average for air samples, if the material is a vivo measurement may be considered unnecessary If the mixture and exposure occurs in only one area, the Dc indicated by the fecal data exceeds 3 reins, the in quarterly average calculation, applicable to all workers in vivo measurement should be performed.
the area, should be performed as for non-mixtures, i.e.,
from samples characterizing conditions in the area. If A quarterly in vivo frequency may be reduced to exposures occur in several areas, the quarterly average semiannual if monthly fecal analyses are made, with an for the mixture may be a time-weighted average for the in vivo measurement at the end of 6 months If any individual, using ( arterly average air samples that result exceeds 7 pCi/day Class (Y) or 460 pCi/day Class characterize full-time conditions in each area. i.e., (W). an in vivo measurement should be performed as soon as practicable. For lower results the following n procedure should be followed. Results from the first 3 QAm= 2 fi QAi specimens should be plotted (semilog) against time, and i=l a best-fitting straight line should be extrapolated to t= 0. Values for (dP /dt)o and T for the individual should be obtained and used in the above equation to where QAi is the quarterly average for the ith area and fi estimate Dc. The actions indicated in Table 4 should is the time fraction of the quarter that the individual then be taken. At the end of the fourth and fifth month, worked in the ith area. As an alternative, QAm may be Dc should again be evaluated using results from all taken as the highest QAi. specimens. At the end of the 6-month period, the in vivo measurement should be performed.
Figure 5 indicates that a urinalysis measurement sensitivity of about 0.7 pCi/I is required to detect the Fecal specimens used for this purpose should be equivalent of I MPDc following a single exposure to obtained after 2 or more days of no exposure. In the Class (Y) materials with neither Class (D) nor Class (W) extrapolation of excretion rate data to t=
0. it is
"'tracer" dusts present. To obtain this sensitivity, a necessary to ignore data points obtained for less than 2 chemical concentration procedure is necessary. Fecal days after exposure.
analysis is recommended as an alternative, using the frequency schedule given for urinalysis. d. Participation If work restrictions that have been imposed do not All personnel whose regular iob assignmentN
involve total exclusion from restricted areas, it is involve work in an area where bioassay ineasurernenI,,
necessary to ensure that bioassay measurements made are required should participate in the bioassay program for the purpose of removing work restrictions are However, as long as air sainple results qualify the area performed at least as frequently as would be required for and group of workers tor the minimum bioasssa purposes of exposure control. program, special consideration may be given in the case
8.1 1-7
of bioassays obtained for the purpose of checking on the ensure that the measurement results are carefully air sampling program, i.e., the first objective shown in reviewed by qualified personnel and that appropriate Table 2. For these bioassays it is acceptable to limit action is taken if the results are considered high. Action participation to a representative sample of the group. should be based on the organ burden, the dose commit The sample should be composed of the most highly ment, or chemical damage to the kidney as indicated exposed or potentially exposed personnel and should (however roughly) by the result. Appropriate actions are include at least 10% of the workers who have regular job shown in Tables 4 and 5 for single intakes. In the case of assignments in the area if the total number of such chronic exposure, when bioassay results indicate that the workers is 100 or more. If the total is between 100 and organ burden is continuing to rise, action should be
10 workers, there should be 10 participants. If the total taken to assure that additional buildup will not interfere is less than 10 workers, all should participate. Thus, with the worker's career. When urinalysis indicates 50%
where the minimum bioassay program is being con or more of the maximum permissible lung burden for ducted, all workers would participate either semi nontransportable uranium, in vivo measurements should annually or annually for monitoring of uranium buildup be undertaken. Work restrictions should be tmposed in the lung or bone, in addition, those in the sample without waiting for in vivo measurements if urinalysis group would participate more frequently if required to indicates more than I permissible lung burden.
do so by Figures 3, 4, or 6. (Note that the in vivo frequency for Class (Y) materials is semiannual in every (3) Diagnostic Evaluation case.) This sampling procedure will be of particular usefulness to those using Figure 4. Where bioassays in addition to the minimum program are conducted, all Diagnostic bioassay measurements are made to workers should participate (see Table 2, footnote e, for .estimate the quantity and distribution of radionuclides exception). in the body after determination that a large deposition has occurred. Actions to be based on diagnostic results Personnel whose duties involve only observance include (I) selection of subsequent measurement tech and who spend less than 25% of the work week in areas niques and frequencies, (2) imposition or removal of where bioassay is required may participate on a limited work restrictions, (3) referral to a physician, and (4) the basis. The interval between bioassay measurements for physician's decision to attempt acceleration of the such personnel should be a matter of judgement based nuclide elimination process.
on the magnitude of the exposure.
f. Action Points e. Action Based on Results Appropriate action as based on bioassay results is This -section presents acceptable correlations be dependent first on the underlying purpose of the tween organ burden, dose commitment, or uranium measurement. uptake and the quantities actually measured using bioassay techniques, thus providing action point criteria
(!) Preparatory Evaluation for purposes of exposure control. Guidance is also given for work restrictions and for referral to a physician.
Where urinalysis for uranium is used to screen personnel prior to job assignment, the presence of any These correlations are derived entirely from urinary uranium, as detected by routine laboratory models. This approach is acceptable for purposes of procedures, should trigger an investigation. Information exposure control. However, these correlations would regarding the location and quantity of uranium in the actually predict the dose commitment or uranium body should be sought, and conservative predictions as uptake only if the bioassay result was without error and td future retention in the body should be made. This if every condition of the models was actually achieved.
information can usually be derived from a review of the worker's previous exposure history, including previous
(1) Dose Commitment and Uptake Correiations, bioassay results, and from subsequent bioassay measure mrents as necessary. Findings should be compared with Single Intake, Class (D) Dust criteria given in Section C.3.f.(8), or with other accept able criteria, and a decision should be made to approve The correlation between dose commitment to the job assignment if acceptable criteria are met, or to the bone and urinary uranium concentration is shown in impose a delay otherwise. Figure 8 for Class (D) materials. In the right hand margin of the figure the recommended actions, from Table 4,
(2) Exposure Control are indicated. The correlation between uptake of uranium by the blood and urinary uranium concen When work is in progress, and bioassay mea tration is shown in Figure 9 for Class (D) materials.
surements are being made routinely, it is essential to Recommended actions, from Table 5, are indicated.
8.11-8
TABLE 4 ACTION DUE TO BIOASSAY MEASUREMENT RESULTS, RADIATION DOSE
Result < 1/5 MPDca Contamination confinement and air sampling capabilities are confirmed. No action required.
1/5 < Result < 1/2 MPDc Contamination confinement and/or air sampling capabilities are marginal. If a result in this range was expected because of past experience or a known incident, any corrective action to be taken presumably has been or is being accomplished; no action is required by the bioassay result. If the result was unexpected:
(I) Confirm result (air sample data review, comparison with other bioassay data, additional bioassay measurements).
(2) Identify probable cause and, if necessary, correct or initiate additional control measures.
(3) Determine whether others could have been exposed and perform bioassay measurements for them.
(4) If exposure (indicated by excreta analysis) could have been to Class (W) or Class (Y) dust, consider the perfor mance of diagnostic in vivo measurements.
1/2 < Result < 1 MPDc Contamination confinement and/or air sampling capabilities are unreliable unless a result in this range was expected because of a known unusual cause, in such cases, corrective action in the work area presumably has been or is being taken, and action due to the bioassay result includes action (7) only. Conditions under which a result in this range would be routinely expected are undesirable. If the result was due to such conditions or was actually unexpected, take actions (1) through (4) and:
(5) If exposure (indicated by excreta analysis) could have been to Class (W) or Class (Y) dust, assure that diagnostic in vivo measurements are performed.
(6) Review the air sampling program, determine why air samples were not representative and make necessary corrections.
(7) Perform additional bioassay measurements as necessary to make a preliminary estimate of the critical organ burden; consider work limitations to ensure that the MPDc is not exceeded.
(8) If exposure could have been to Class (Y) dust, bring expert opinion to bear on cause of exposure, and continue operations only if it is virtually certain that the limit of I MPDc will not be exceeded by any worker.
Result > I MPDc Contamination confinement and/or air sampling capabilities are not acceptable, unless a result of this magnitude was expected because of a known unusual cause: in such cases, corrective action in the work area presumably has been ov is being taken, and action due to the bioassay result includes actions (10) and (11) only. Prevalent conditions under which a result in this range would be expected are not acceptable. If the result was due to such conditions or was actually unexpected, take actions(I) through (7) and:
(9) Take action (8), regardless of dust classification.
(10) Establish work restrictions as necessary for affected employees.
(11) Perform individual case studies (bioassays) for affected employees.
aThe annual MPDC is a 50-yr integrated dose of 15 rems to the lung or 30 reins to the bone.
8.11-9
TABLE 5 ACTION DUE TO BIOASSAY MEASUREMENT RESULTS, CHEMICAL TOXICITY
Result < 1/2 L4 Contamination confinement and air sampling capabilities are adequate. No action require
d. I
1/2 L < Result < L
Contamination confinement and/or air sampling capabilities do not provide an adequate margin of safety. If a result in this range was expected because of past experience or a known incident, any corrective action to be taken presumably has been or is being accomplished; no action is required by the bioassay result. If the result was unexpected:
(1) Confirm result (air sample data review, comparison with other bioassay data, additional bioassay measurements).
(2) Identify probable cause and, if necessary, correct or initiate additional control measures.
(3) Determine whether others could have been exposed and perform bioassay measurements for them.
(4) Determine why the bioassay result was not predicted by the air sampling program and make necessary corrections.
(5) Consider work limitations to ensure that L is not exceeded.
(6) If bioassay result was near L, bring expert opinion to bear on cause of exposure, and continue operations only if it is virtually certain that L will not be exceeded by any worker.
Result > L
Contaminatiow confinement and/or air sampling capabilities are not acceptable, unless a result of this magnitude was expected because of a known unusual cause; in such cases, corrective actuon in the work area presumably has been or is being taken, and action due to the bioassay result includes actions (7) and (8) only. Prevalent conditions under which a result in this range would be expected are not acceptable. If the result was due to such conditions or was actually unexpected, take actions ( I ) through (6) and:
(7) Establish work restrictions as necessary for affected employees.
(8) Have additional urine specimen tested for albuminuria under direction of a physician.
aL is 2.7 ing of uranium in the bWood. Assume uptake is 43% of intake.
(2) Class (D) Dust, Dual Action Requirements (3) Dose Commitment Correlation, Single Intake, Class (W)and Class (Y) Dust, Excreta Analysis If the urinary uranium concentration is suf ficiently large, action due to both radiation dose and The correlation between dose commitment to chemical toxicity may be necessary. Both Figures 8 and the lung, urinary uranium concentration, and uraniuirn
10 should be consulted for this determination. Figure I I fecal excretion rate is shown in Figures 12 through 14 presents values of specific activity acceptable for con for Class (W) and Class (Y) materials. Recommended verting activity to gravimetric units. actions, from Table 4, are indicated.
For exposure to multiple enrichments, values (4) Dose Commitment Correlation, Single Intake, from Figure 11 should be weighted to obtain an Clan (W) and Class (Y) Dust, In Vivo appropriate specific activity. If the weighting factors are unknown, the smallest specific activity present shou!d be The correlation between dose commitment to used. the lung and the mass of U-235 measured in the thorax
8.11-10
by in vivo techniques is shown in Figure 15 for Class (W) control the chronic levels due to continuous intake do materials and in Figure 16 for Class (Y) materials. not alter the approach outlined for the detection of Recommended actions, from Table 4, are indicated. single intakes.
These figures are applicable to uranium of 20 w/o U-235; scaling factors are provided in Figure 17 for The correlation between in vivo measurements other enrichments. of U-235 and lung burden is shown in Figure 19. In.vivo measurements are considered to be much more reliable
(5) Exposure to Mixtures than urinalysis for Class (W) and Class (Y) materials.
However, urinalysis may be used to indicate that in vivo If a positive urinalysis specimen is obtained measurements are promptly needed. rThe average value following exposure to a mixture that included significant from several urinalysis results (R) can be used with quantities of Class (Y) materials, actions (1) through Figure 20 to estimate the number of maximum per
(11) in Table 4 should be taken. missible lung burdens (MPLB = 0.016 pCi). Arrange ments for in vivo measurements should be undertaken if the exposure was to a mixture of Class (W) when AR is found to exceed 0.5. If ý'R >1, additional dust and-Class (D) dust with chemical toxicity limiting, exposure should be avoided until in vivo results are the urinary uranium mass concentration should be available.
determined and the curves in Figure 9 used to determine the required actions from Table 5; the activity concen (7) Referral to a Physician tration should also be determined, using Figure 12 with Table 4. When confirmed bioassay measurement results indicate that the Maximum Permissible Annual Dose If exposure was to a mixture of Class (W) dust (MPAD) to the lung or bone has been or will be and Class (D) dust with bone dose limiting, it is exceeded by a factor of 2, the affected individual should necessary to estimate the fraction of the dust inhaled be so informed, and referral to a physician knowledge that was Class (W), fw, and the fraction that was Class able in the biological effects of radiation and conversant (D), fd. It is also necessary to determine the urinary in the nature and purpose of regulatory dose limits excretion factors, Ew and Ed, that would be applicable should be considered.
at the timie the specimen was obtained; Figure 18 may be used for this purpose. If R represents the bioassay When confirmed bioassay results indicate that result in pCi/day, Rd the Class (D) component and Rw an exposure to uranium has resulted in an uptake by the the Class (W) component, such that R = Rd + Rw, then blood of more than 2.7 mg within 7 consecutive days or less, the affected individual should be informed of his Rd = fdEdR/(fdEd + fwEw) exposure and referred to a physician knowledgeable in the chemical effects of internally administered uranium.
aw = fwEwR/(fdEd + fwEw)
(8) Work Restrictions These results should be converted to concentra tion using the factor 1.4 I/day. Then the curves in AEC regulations establish an upper limit on Figure 8 or Figure 12 should be used to determine the exposures during a specified period of time; it follows required actions from Table 4. that work restrictions may be necessary to prevent exposures from exceeding this limit. Such restrictions If positive in vivo results are obtained following may also be necessary to prevent the deposition of exposure to a mixture of Class (W) and Class (Y) uranium in the body in such quantity that:
materials, Figure 16 should be used to determine the required actions from Table 4. (i) the mass of uranium entering the blood will exceed 2.7 mg in 7 consecutive days;
(6) Lung Burden Correlations, Continuous Intake (ii) the activity present in the lung will pro duce an annual dose-equivalent to the In some working areas airborne uranium is pulmonary region exceeding 15 reins;
routinely present and is responsible for the chronic (iii) the activity present in the bone will appearance of uranium in urine. Continuous intakes of produce an annual dose-equivalent to the this nature may also be responsible for chronically bone exceeding 30 reins.
positive in vivo measurement results. Under these condi tions positive bioassay results are expected, and the For personnel who have a body burden of monitonng tasks are to measure the lung burden buildup uranium that is producing an annual dose-equivalent and to identify single intake peaks above this expected greater than 15 rems to the pulmonary region of the level. Thus it is evident that for purposes of exposure lung or 30 reins to the bone or both, work restrictions
8.111-11
may be imposed as necessary to assure that the to chemical toxicity, the objective is to determine additional radiation dose from sources under the control whether the uranium uptake was sufficient to cause of the employer would be considered negligible by a kidney damage. The radiological objectives are to esti qualified health physicist. mate (1) the quantity of uranium present in the organ of reference, (2) the rate of elimination, (3) the magnitude
4. Diagnostic Guidance of the original deposition, and (4) the dose commitment. I
As with exposure control monitoring, use of models is In previous sections a monitoring program has been necessary. However, it is usually possible in a given described which should detect every instance of serious individual's case to use factual data rather than some of deposition of uranium in the body. Once a deposition of the assumptions, and every opportunity for such refine this nature has been identified, the bioassay purpose ment .should be taken. This subject is treated in changes from exposure control to diagnosis. With respect considerab!e detail in WASH-1251,Section V.
8.11-12
A4R SAMPLING DATA
NOT REPRESENTATIVE I REPRESENTATIVE
1 - QTR. AVE,_<10% DAC 1 - QTR. AVE.>10% DAC
MAXIMUM_< 25% DAC MAXIMUM >25% DAC
USE OF NON-REPRESENTATIVE AIR [MINIMUM BIOASSAY PROGRAM]
SAMPLING DATA IS NOT ACCEPTABLE
IN DETERMINING THE 1 - QTR. AVE.
SADDITIONAL BIOASSAYS I
Figure 1 Criteria for Initiating Additional Bioassays, Routine Conditions Figure 2 Criteria for Diagnostic Bioassays Durings Special Investigations
8.1 1-13
~i2 LU
z wig laj
010
100 101 102 10310
MEASUREMENT SENSITIVITY LIMIT (pCi/I)
Figure 3 Maximumn Time Between Specimens to Detect 1 MPDc, Class (D) Uranium Dust, w/o U-235 >80
,
3 1 1I I I TII1 l I1111 " V! IIIT _
S102 u - USE FIGURE 11 TO CONVERT
TO ACTIVITY UNITS.
wI
9- 0
uJ 101 -
100 - I I 11111 I 111 X1 I 1 11111 III1 I I I I
10-1 100 101 102 103 104 MEASUREMENT SENSITIVITY LIMIT (pg/I)
Figure 4 Maximum Time Between Specimens to Detect Uptake of
2.7 mg Class (D) Uranium, w/o U-235:580
103 4 6 .I-12..
0 WJ
I I I I I III I I I( iiY)
CLASS (Y)
10 2q_
zLu z
2 10
uj I I I I I I Iif I I
100 , I 1 1 1 Hill *llv I A L= a ..... . . . . ....
102 10-1 100 101
101 Lo3 MEASUREMENT SENSITIVITY
LIMIT (pCi/I) MEASUREMENT SENSITIVITY LIMIT (pCi/I)
Figure 5 Maximum Time Between Specimens to Detect 1 MPDc, Class (W) or Class (Y) Uranium V
C
-- I
I'j I I 11111 i I I 1111U I I 111111 I I I 11111 I ! I III_
Ln zU. 20 w/o U-235 I- 102 w z
2 Lu cn U.1 w
Lu
--4 uz
93% U-235
.- I,,
III',
IV
I. I 4 6-.
t-.
1001 I I I I I III I --
I
.
I IIIll
.- I. . .I .. -- ..
I I I
.
IIIII
. . . ..
I I 1 11111
. . . . .
I III
I I I lll
11 1 1 1 1 i
10 0 101 102 103 MEASUREMENT SENSITIVITY LIMIT (pg U-235)
Figure 6 Maximum Time Between Measurements to Detect 1 MPDc In Vivo, Class (W)
TIME BETWEEN MEASUREMENTS (DAYS)
._ 0
--- f:*T* F
c m
"os m Zm
00
m a *
103
~~~~~~~ ,,t,/ 3ris1M~ -- TABLE
LL .7 .......... .............. 'w mm
0
2 6 rams I- /
C N
RESU
w
0 10"0
N(
10-21 1 ItI I I l 1
100 101 102 103 URINARY URANIUM CONCENTRATION (pCi/I)
Figure 8 Dose Commitment Indicated by Model vs. Urinary Uranium Concentration, Class (D), Single Intake
8.11-19
104I 1 1I 1 I 1II I l I I
103 E
-j S10 2
,o
0
U
a 100
CL100
AI
10.1 ........ .. / .. ..I
10- 100 101 102 URINARY URANIUM CONCENTRATION (pg/I)
Figure 9 Uptake in Blood Indicated by Model vs. Urinary Uranium Concentration, Class (D), Single Intake
8.11-20
102. I 1 ,**" I 1 S101 zA
wA
- Z 10
RESULTS LEFT OF BAND REQUIRE NO ACTION.
RESULTS WITHIN BAND REQUIRE ACTIONS
(1) THRU (6), TABLE 5 RESULTS RIGHT OF BAND REQUIRE ACTIONS
(1) THRU (8), TABLE 5
10"1 __ 1_ 1 _ 1 !1_
_11111_ 1 1 I I 111111 I I 1 111i
1
10-1 100 101 102 103 104 URINARY URANIUM CONCENTRATION (pCi/I)
Figure 10 Action Guide for Urinalysis Results Following Single Intake of Uranium, Chemical Toxicity
I .
10.4
--I 1 0
S =(0.4 + 0.38E + 0.0034E 2 ) 10-6 K 0 00
_ _
I 00
S10-6 L) 0 Al DATA
< 0 GULF DATA
U.o IAEA SS NO. 6 uli A ORO-651 EQUATIOF
S (U-dep) 3.6 x 10-7 Ci/gm
0 20 40 60 80 100
WITHOUT U-235, E
Figure 11 Specific Activity for Mixtures of U-238, U-234 and U-235
8.11-22
1I III II
... CLASS (Y)
ol* o*
102 4 V RE
-J
ACTIC
15 reins =I MPDc TAL
I-U..
0;-
101 0
io
...................... ...... .
.5 rtms -
........... !........... elm
1 /2 < F
ACTI
S-- __ 1/5<R
ACTIO
UU
lo- 000
S~REE
10-1
100 101 102 103 URINARY URANIUM CONCENTRATION (pCi/l)
Figure 12 Dose Conmmitment Indicated by Model vs. Urinary Uranium Concentration, Class (W) and (Y), Single Intake
8.11-23
,C03.
102 1 R E SU LT M P Oc
>1 oQ
0
2 1O,
......... ...
00
... I........
..........
10ACTIONS
15 em
....... TABLE 4
(1) THRU 11)
1/2 eRESULT S1I MPD,
ACTIONS (11) THRU W(
0= ... .............. ;*
cc -
.. .......... .... .... .. 1/5 < RESULT S1 /2 MPO,
-ACTIONS (1) T44RU 14)
A; RESULT -1 /5 MPDC
0 100 ! NO ACTION
Lkl
0
a
.1
10-2 1 1 1 1 1l
100 101 102 103 URANIUM FECAL EXCRETION RATE (pCi/DAY)
Figure 13 Dose Commitment Indicated by Model vs. Uranium Fecal Excretion Rate, Class (W), Single Intake L
8.11-24
102 REI
ACT 10
TABLI
0........................................a~* 000 0:ass................... Noennn
10.
1
_, ......... . . . . s............u ,.. . . . . . . . . . ,.. _ 1/2< F
ACTIC
1/6< R
ACTIO
2 100
20
10-1
100 101 102 103 URANIUM FECAL EXCRETION RATE (pCi/DAY)
Figure 14 Doss Commitment Indicated by Model Vs. Uranium Fecal Excretion Raft, Class (Y), Single Intake
8.11-25
104 S20 w/o U-235
15-ein.1 PDCT"
0 101 120 35 IM
reins A
1/
tN y!yo (p U-235)
Figure 15 Dose Commitment Indicated by Model vs. In Vivo Result, Cless (W), Single Intake
3. 11-26
104
10
20 w/o U-235A
0
102
0
- oooe)mlm olao o mla eao m
0 RESULT >1 MPOc U.
I
2) ACTIONS (1) THRU 111)
Is rams 1 MPD, TABLE 4
1/2- RESULTS!_I MPD¢
101 7.5 rin 1 ACTIONS (1) THRU 68)
.. ~ ....... .................
ag
1f5 <RESULTS1I2 MPO,
ACTIONS (1) THRU (4)
100
RESULT *r1/5 MPD,
NO ACTION
10"1
101 102 103 104 IN VIVO RESULT (pg U-235)
,Figure 16 Don Commitment Indicated by Model vs. In Vivo Result, Class (Y), Single Intake
8.11-27
U
At ! 11 I I I r I t
711 I.5 -
0
z
,/
o0
00J
1.2
1.1
-ii_
1.0
A
U EU zu 30 40 50 60 70 80 90 100
w/o U-235 Figure 17 fmiichiment Scaling Factors for Model Dose Commitment Curves, InViyD Measurement Following Single Exposure to Class (Wl or Class (Y) Uranium Dust
'4
- 10
0
10-4 z
10
100 1011013 TIME (DAYS AFTER INTAKE)
Figure 18 Urinary Uranium Excretion Factors for Determining RD and Rw
8.11-29
LO)
200
100 - l 1 1 L 1 L L 1 I
0 10 20 30 40 50 60 70 80 90 100
w/o U-235 FIGURE 19 Equilibrium Mass of U-235 in the Lung Equivalent to 1 Ma, n rrn Permissible Lung Burden
102 1111 1 11I1!111 IuI I I I I 1
101
100
0.
a.
IL
10-11 w
101 102 103 104 TIME AFTER BEGINNING OF EXPOSURE (DAYS)
Figure 20 Model for Interpreting Urinalysis Results During Continuous Exposure to Constant Concentration of Uranium in Air
8,11-31