Regulatory Guide 4.14
| ML003739941 | |
| Person / Time | |
|---|---|
| Issue date: | 04/25/1980 |
| From: | Office of Nuclear Regulatory Research |
| To: | |
| References | |
| Reg Guide 4.14, Rev 1 | |
| Download: ML003739941 (23) | |
I
0o*UNITED STATES
NUCLEAR REGULATORY COMMISSION
WASHINGTON, D. C. 20555 April 25, 1980
Regulatory Guide 4.14 Revision 1 REGULATORY GUIDE DISTRIBUTION LIST (DIVISION 4)
SUBJECT: Regulatory Guide 4.14, Revision 1, "Radiological Effluent and Environmental Monitoring at Uranium Mills"
Regulatory Guide 4.14 was originally issued for public comment in 1977. That version has now been revised as appropriate in response to public comments.
In addition, the scope of the guide has been expanded to include offsite environmental monitoring. The environmental monitoring programs described in this revision were previously included in NRC publication NUREG-0511, "Draft Generic Environmental Impact Statement on Uranium Milling," published for comment in April 1979.
The NRC staff developed the regulatory positions in this Revision 1 of Regulatory Guide 4.14 over a long period of time, taking into-account public input as described above. The positions are already being used by the NRC
staff in the licensing process. However, this revision represents the first opportunity for public review of the staff position as a consolidated document.
For this reason, it is being provided to all addressees on the Division 4 distribution list. Comments on regulatory guides are encouraged at all times, and comments on this guide will be particularly helpful to the NRC staff in evaluating the need for another revision to this guide. Comments will be most useful if they are submitted within two months of the publication of the guide.
'Ug"ector Robert B. Mino Office of Standards Development
Revision 1 April 1980
U.S. NUCLEAR REGULATORY COMMISSION
REGULATORY GUIDE
OFCE OF STANDARDS0EVE.OPMENT
REGULATORY GUIDE 4.14 RADIOLOGICAL EFFLUENT AND ENVIRONMENTAL MONITORING
AT URANIUM MILLS
A. INTRODUCTION
This guide describes programs acceptable to the NRC
staff for measuring and reporting releases of radioactive Uranium mill operators are required by Nuclear Regula materials to the environment from typical uranium mills.
tory Commission (NRC) regulations and license conditions to conduct radiological effluent and environmental moni The programs described in this guide are not require toring programs. Regulations applicable to urafium milling ments. Licensing requirements are determined by the NRC
are contained in 10 CFR Part 20, "Standards for Protection staff on a case-by-case basis during individual licensing Against Radiation," and Part 40, "Domestic Licensing of reviews. Individual applicants or licensees may propose Source Material." For example, § 40.65, "Effluent Moni alternatives for new or existing monitoring programs that toring Reporting Requirements," of 10CFR Part40 need not necessarily be consistent with this guide. The requires the submission to the Commission of semiannual justification for such alternatives will be reviewed by the reports containing information required to estimate doses NRC staff, and the acceptability of proposed alternatives to the public from effluent releases. will be determined on a case-by-case basis during individual licensing reviews. For example, it is anticipated that opera Information on radiation doses and the radionuclides in tional monitoring programs that do not include at least a mill's effluents and environment both prior to and during three continuous air samples at the site boundary will operations is needed by the NRC staff: include more extensive stack sampling and more sampling locations than are described in this guide as well as meteor
1. To estimate maximum potential annual radiation ological data and additional environmental monitoring doses to the public resulting from effluent releases. requirements.
2. To ascertain whether the regulatory requirements of
B. DISCUSSION
the NRC (including 10 CFR Part 20 dose limits, release limits, and the "as low as is reasonably achievable" require The radiation dose an individual receives can be deter ment), mill license conditions, and the requirements of mined only if the radionuclides to which an individual is
40 CFR Part 190, "Environmental Radiation Protection exposed are known. Therefore, monitoring programs should Standards for Nuclear Power Operations," have been met. provide accurate information on the specific radionuclides in effluents from a mill, its ore piles, and its tailings reten
3. To evaluate the performance of effluent controls, tion system and in the surrounding environment.
including stabilization of active and inactive tailings piles.
Methods of sampling and analysis for the radionuclides
4. To evaluate the environmental impact of milling opera associated with uranium milling are discussed in sources tions, both during operations and after decommissioning. listed in the bibliography. The listing of these documents is not meant to be all inclusive, nor does it constitute an
5. To establish baseline data to aid in evaluation of endorsement by the NRC staff of all of the methods in all decommissioning operations or decontamination following of the listings. Rather, these listings are provided as sources any unusual releases such as a tailings dam failure. of information to aid the licensee in developing a monitor ing program.
The substantial number of changes In this revision ha made it The sampling program described below is divided into impractical to Indicate the changes with lines in the margin. two parts: preoperational monitoring and operational USNRC REGULATORY GUIDES Comments should be sent to the Secretary of the Commission, U.S. Nuclear Regulatory Commission Washington, D.C. 20555, Regulatory Guides are Issued to describe and make available to the Attention: Docketlng and Service Branch.
public methods acceptable to the NRC staff of Implementing specific parts of the Commission's regulations, to delineate tech- The guides are Issued in the following ten broad divisions:
nlques used by the staff In evaluating specific problems or postu lated accidents, or to provide guidance to applicants. Regulato 1. Power Reactors 6. Products Guides are not substitutes for regulations, and compilance witl* 2 Research and Test Reactors 7. Transportation them Is not required. Methods and solutions different from those set Fuels and Materials Facilities 8. Occupational Health out In the guides will be acceptable If they provide a basis for the 4. Envirormlmetai and Siting . Antitrust and Financial Review findings requisite to the issuance or continuance of a permit or 5. MaterIals and Plant lrotection 10. General license by the Commission.
Copies of Issued guides may be purchased at the current Government Comments and suggestions for improvements In these guides are Printing Office price. A subscription service for future guides in spe encouraged at all times, and guides will be revised, as pPro riata, ~cific livisions Is available through the Government Printing Office.
to accommodate comments and to reflect new Informat on or Information an the subscription service and current GPO prim may experience. This guide was revised as a result of substantive com- be obtained by writing the U.S. Nuclear Regulatory Commission, ments received from the public and additional staff review. Washington, D.C. 20555, Attention: Publications Sales Manager.
monitoring. Preoperational data is submitted to the NRC as 1.1.2 Water Samples part of the application process. Operational data is reported as required by § 40.65 of 10 CFR Part 40 and specific Samples of ground water should be collected quarterly license conditions and at times of license renewal. from at least three sampling wells located hydrologically down gradient from the proposed tailings area, at least
C. REGULATORY POSITION
three locations near other sides of the tailings area, and one well located hydrologically up gradient from the tailings I. PREOPERATIONAL MONITORING area (to serve as a background sample). The location of the ground-water sampling wells should be determined by An acceptable preoperational monitoring program is hydrological analysis of the potential movement of seepage described below and summarized in Table I. At least twelve from the tailings area, and the basis for choosing these loca consecutive months of data, including complete soil sam tions should be presented when data is reported. Wells drilled pling, direct radiation, and radon flux data, should be sub close to the tailings for the specific purpose of obtaining mitted to the NRC staff prior to any major site construc representative samples of ground water that may be affect tion. A complete preoperational report with twelve consec ed by the mill tailings are preferable to existing wells.
utive months of data should be submitted prior to beginning milling operations. Prior to the start of local mining opera Ground-water samples should also be collected quarterly tions, if possible, monitoring data, including airborne radon from each well within two kilometers of the proposed measurements, should be submitted to the NRC staff. tailings area that is or could be used for drinking water, watering of livestock, or crop irrigation.
Applicants may propose alternatives to this preopera tional program. However, equivalent alternatives should be Samples of surface water should be collected quarterly proposed for the operational program so that the programs from each onsite water impoundment (such as a pond or lake)
remain compatible. and any offsite water impoundment that may be subject to seepage from tailings, drainage from potentially contami
1.1 Preoperational Sampling Program nated areas, or drainage from a tailings impoundment failure.
1.1.1 Air Samples Samples should be collected at least monthly from streams, rivers, any other surface waters or drainage systems Air particulate samples should be collected continuously crossing the site boundary, and any offsite surface waters at a minimum of three locations at or near the site bound that may be subject to drainage from potentially con ary. If there are residences or occupiable structures within taminated areas or from a tailings impoundment failure.
10 kilometers of the site, a continuous outdoor air sample Any stream beds that are dry part of the year should be should be collected at or near the structure with the highest sampled when water is flowing. Samples should be collected predicted airborne radionuclide concentration due to milling at the site boundary or at a location immediately downstream operations and at or near at least one structure in any area of the area of potential influence.
where predicted doses exceed 5 percent of the standards in
40 CFR Part 190. A continuous air sample should also be 1.1.3 Vegetation, Food, and Fish Samples collected at a remote location that represents background conditions at the mill site; in general, a suitable location Forage vegetation should be sampled at least three times would be in the least prevalent wind direction from the site during the grazing season in grazing areas in three different and unaffected by mining or other milling operations. sectors having the highest predicted airborne radionuclide concentration due to milling operations.
Normally, filters for continuous ambient air samples are changed weekly or more often as required by dust loading. At least three samples should be collected at time of harvest or slaughter or removal of animals from grazing for The sampling locations should be determined according each type of crop (including vegetable gardens) or livestock to the projected site and milling operation. Preoperational raised within three kilometers of the mill site.
sampling locations should be the same as operational locations. The following factors should be considered in Fish (if any) samples should be collected semiannually determining the sampling locations: (1) average meteorolog from any bodies of water that may be subject to seepage or ical conditions (windspeed, wind direction, atmospheric surface drainage from potentially contaminated areas or stability), (2) prevailing wind direction, (3) site boundaries that could be affected by a tailings impoundment failure.
nearest to mill, ore piles, and tailings .piles, (4) direction of nearest occupiable structure (see footnotes of Tables I and 1.1.4 Soil and Sediment Samples
2), and (5) location of estimated maximum concentrations of radioactive materials. Prior to initiation of mill construction (and if possible prior to mining), one set of soil samples should be collected Samples should be collected continuously, or for at least as follows:
one week per month, for analysis of radon-222. The sam pling locations should be the same as those for the continu a. Surface-soil samples (to a depth of five centimeters)
ous air particulate samples. should be collected using a consistent technique at 300-
4.14-2
meter intervals in each of the eight compass directions out Air samples collected for radon should be analyzed for to a distance of 1500 meters from the center of the milling radon-222.
area. The center is defined as the point midway between the proposed mill and the tailings area. The results of analyses of air samples should be used to determine the radionuclide concentrations for the sampling b. Surface-soil samples should also be collected at each locations.
of the locations chosen for air particulate samples.
All ground-water samples collected near the tailings area c. Subsurface samples (to a depth of 1 meter) should be should be analyzed for dissolved natural uranium, thorium collected at the center of the milling area and at a distance 230, radium-226, polonium-210, and lead-210. Ground-water of 750 meters in each of the four compass directions. samples from sources that could be used as drinking water for humans or livestock or ctop irrigation should also be Soil sampling should be repeated for each location analyzed for suspended natural uranium, thorium-230,
disturbed by site excavation, leveling, or contouring. radium-226, polonium-2 10, and lead-210.
One set of sediment samples should be collected from the Surface-water samples from water impoundments should same surface-water locations as described in Section 1.1.2. be analyzed quarterly for natural uranium, thorium-230, and For surface water passing through the site, sediment should radium-226 and semiannually for lead-210 and polonium-2 10.
be sampled upstream and downstream of the site. Samples The samples should be analyzed separately for dissolved and should be collected following spring runoff and in late suspended radionuclides.
summer, preferably following an extended period of low flow.
In each location, several sediment samples should be col Surface-water samples from flowing surface water should lected in a traverse across the body of water and composited be analyzed monthly for natural uranium, thorium-230 and for analysis. radium-226 and semiannually for lead-210 and polonium-210.
The samples should be analyzed separately for dissolved and suspended radionuclides.
1.1.5 Direct Radiation The results of analyses of water samples should be used to Prior to initiation of mill construction (and if possible determine the radionuclide concentrations for the sampling prior to mining), gamma exposure rate measurements locations.
should be made at 150-meter intervals in each of the eight compass directions out to a distance of 1500 meters from Vegetation, food, and fish (edible portion) samples S-thearea. Measurements should also be center of the milling should be analyzed for natural uranium, thorium-230,
made at the sites chosen for air particulate samples. radium-226, lead-210, and polonium-210.
Measurements should be repeated for each location All soil samples should be analyzed for radium-226. Soil disturbed by site excavation, leveling, or contouring. samples collected at air particulate sampling locations and ten percent of all other soil samples (including at least one sub Gamma exposure measurements should be made with surface set) should be analyzed for natural uranium, thorium passive integrating devices (such as thermoluminescent 230, and lead-210. Analysis of extra soil samples may be dosimeters), pressurized ionization chambers, or properly necessary for repeat samples collected at locations disturbed calibrated portable survey instruments. by site excavation, leveling, or contouring.
Direct radiation measurements should be made in dry Sediment samples should be analyzed for natural uranium, weather, not during periods following rainfall or when soil thorium-230, radium-226, and lead-210.
is abnormally wet.
2. OPERATIONAL MONITORING
1.1.6 Radon Flux Measurements An acceptable monitoring program to be conducted during Radon-222 flux measurements should be made in three construction and after the beginning of milling operations separate months during normal weather conditions in the is described below and summarized in Table 2. The results spring through the fall when the ground is thawed. The of this program should be summarized quarterly and sub measurements should be made at the center of the milling mitted to NRC semiannually pursuant to § 40.65 of 10 CFR
area and at locations 750 and 1500 meters from the center Part 40. An acceptable reporting format is shown in Table 3.
in each of the four compass directions. Measurements should not be taken when the ground is frozen or covered 2.1 Operational Sampling Program with ice or snow or following periods of rain.
2.1.1 Stack Sampling
1.2 Analysis of Preoperational Samples Effluents from the yellowcake dryer and packaging stack Air particulate samples should be analyzed for natural should be sampled at least quarterly during normal opera uranium, thorium-230, radium-226, and lead-2 10. tions. The sampling should be isokinetic, representative,
4.14-3
and adequate for determination of the release rates and contaminated areas or from a tailings impoundment failure.
concentrations of uranium. The sampling should also be Stream beds that are dry part of the year should be sampled adequate for the determination of release rates and con when water is flowing. Operational samples should be centrations of thorium-230, radium-226, and lead-210 collected upstream and downstream of the area of potential if this data cannot be obtained from other sources. influence.
Other stacks should be sampled at least semiannually. Any unusual releases (such as surface seepage) that are The samples should be representative (not necessarily not part of normal operations should be sampled.
isokinetic) and adequate for the determination of the release rates and concentrations of uranium, thorium-230, .2.1.4 Vegetation, Food, and Fish Samples radium-226, and lead-2 10.
Where a significant pathway to man is identified in All stack flow rates should be measured at the time of individual licensing cases, vegetation, food, and fish samples sampling. should be collected as described below.
Forage vegetation should be sampled at least three times
2.1.2 Air Samples during the grazing season in grazing areas in three different sectors having the highest predicted airborne radionuclide Air particulate samples should be collected continuously concentration due to milling operations.
at (1) a minimum of three locations at or near the site boundary, (2) the residence or occupiable structure within At least three samples should be collected at the time of
10 kilometers of the. site with the highest predicted air harvest or slaughter or removal of animals from grazing for borne radionuclide conicentration, (3) at least one residence each type of crop (including vegetable gardens) or livestock or occupiable structure where predicted doses exceed 5 raised within three kilometers of.the mill site.
percent of the standards in 40 CFR Part 190, and (4) a remote location representing background conditions. The Fish (if any) samples should be collected semiannually sampling locations should be the same as those for the from any bodies of water that may be subject to seepage or preoperational air samples (see Section 1.1.1). The sampling surface drainage from potentially contaminated areas or should be adequate for the determination of natural ura that could be affected by a tailings impoundment failure.
nium, thorium-230, radium-226, and lead-2 10.
2.1.5 Soil and Sediment Samples Normally, filters for continuous ambient air samples are changed weekly or more often as required by dust loading. Surface-soil samples should be collected annually using a consistent technique at each of the locations chosen for air Samples should be collected continuously at the same particulate samples as described in Section 2.1.2.
locations, or for at least one week per month, for analysis of radon-222. Sediment samples should be collected annually from the surface-water locations described in Section 2.1.3.
2.1.3 Water Samplea
2.1.6 Direct Radiation Samples of ground water should be collected from at least three sampling wells located hydrologically down Gamma exposure rates should be measured quarterly at gradient from the tailings area and from one background the sites chosen for air particulate samples as described in well located hydrologically up gradient. The samples should Section 2.1.2. Passive integrating devices (such as thermo be collected monthly through the first year of operation luminescent dosimeters), pressurized ionization chambers, and quarterly thereafter from the same downslope and or properly calibrated portable survey instruments should background wells that were used for preoperational samples be used (see Regulatory Guide 4.13).
(see Section 1.1.2).
2.2 Analysis of Operational Samples Samples should be collected at least quarterly from each well within two kilometers of the tailings area that is or Samples from the yellowcake dryer and packaging stack could be used for drinking water, watering of livestock, or should be analyzed for natural uranium. Samples should crop irrigation. also be analyzed for thorium-230, radium-226, and lead-2 10
if this data cannot be obtained from other sources such as Samples should be collected at least quarterly from each isotopic analysis of yellowcake product. Samples from onsite water impoundment (such as a pond or lake) and any other stacks should be analyzed for natural uranium, offsite water impoundment that may be subject to seepage thorium-230, radium-226, and lead-2 10.
from tailings, drainage from potentially contaminated areas, or drainage from a tailings impoundment failure. Air particulate samples should be analyzed for natural uranium, thorium-230, radium-226, and lead-2 10.
Samples should be collected at least monthly from any surface water crossing the site boundary and offsite streams Air samples collected for radon should be analyzed for or rivers that may be subject to drainage from potentially radon-222.
4.14-4
The results of analyses of air samples should be used to The lower limits of detection for analysis of other determine the radionuclide release rates for the stacks and samples should be as follows:
the radionuclide concentrations for the stacks and other
-J sampling locations. U-natural, Th-230, Ra-226 in air - I x 10-16 Ci/ml Water samples should be analyzed for natural uranium, Pb-210 in air -2 x I 0"' 5 iCi/ml thorium-230, radium-226, polonium-210, and lead-210.
Rn-222 - 2 x 10"1°/Ci/ml Ground-water samples from sources not expected to be used as drinking water should be analyzed for dissolved U-natural, Th-230, Ra-226 in - 2 x I010
0 .LCi/ml radionuclides. Ground-water samples from sources that water could be used as drinking water for humans or livestock and all surface-water samples should be analyzed separately for Po-210 in water - lx 10-9j Ci/ml dissolved and suspended radionuclides. These results should be used to determine radionuclide concentrations for Pb-210 in water - Ix 10-9 paCi/ml ground water and natural bodies of water.
U-natural, Th-230, Ra-226, - 2 x 10-7/ Ci/g All vegetation, food, and fish (edible portion) samples Pb-210 in soil and sediment should be analyzed for radium-226 and lead-210. (dry)
All soil samples should be analyzed for natural uranium, U-natural, Th,230 in vegetation, - 2 x 10-7/ Ci/kg radium-226, and lead-210. food, and fish (wet)
All sediment samples should be analyzed for natural Ra-226 in vegetation, food, and - 5 x 10-8/ .Ci/kg uranium, thorium-230, radium-226, and lead-210. fish (wet)
6
3. QUALITY OF SAMPLES Po-210,.Pb-210 in vegetation, -I x 10 tCi/kg food, and fish (wet)
Provisions should be made to ensure that representative samples are obtained by use of proper sampling equipment, Obviously, if the actual concentrations of radfonuqlides proper locations of sampling points, and proper sampling being sampled are higher than the lower limits of detection procedures (see bibliography). indicated above, the sampling and analysis procedures need only be adqquate to measure the actual concentrations.
Air samples may be composited for analysis if (1) they In such cases, the standard deviation estimated for random are collected at the same location and (2) they represent a error of the analysis should be no greater than 10% of the sampling period of one calendar quarter or less. Air samples measured value.
should not be composited if (1) they represent a sampling An acceptable method for calculating lower limits of period of more than one calendar quarter, (2) they are from different sampling locations, or (3) the samples are to be detection is described in the appendix to this guide.
analyzed for radon-222.
6. PRECISION AND ACCURACY OF RESULTS
Samples collected for analysis of radon-222 should be analyzed quickly enough to minimize decay losses. 6.1 Error Estimates Samples other than air samples should not be composited. The random error associated with the analysis of samples should always be calculated. The calculation should take
4. SOLUBILITY OF AIRBORNE RADIOACTIVE into account all significant random uncertainties, not MATERIAL merely counting error.
Table II of Appendix B, "Concentrations in Air and If the analyst estimates that systematic errors associated Water Above Natural Background," to 10 CFR Part 20 lists with the analysis are significant relative to the random separate values for soluble and insoluble radioactive mate error, the magnitude of the systematic error should be rials in effluents. In making comparisons between airborne estimated, effluent concentrations and the values given in Table II of Appendix B to 10 CFR Part 20, the maximum permissible 6.2 Calibration concentrations for insoluble materials should be used.
Individual written procedures should be prepared and
5. LOWER LIMIT OF DETECTION used for specific methods of calibrating all sampling and measuring equipment, including ancillary equipment. The The lower limits of detection for stack effluent samples procedures should ensure that the equipment will operate should be 10% of the appropriate concentration limits with adequate accuracy and stability over the range of its listed in Table II of Appendix B to 10 CFR Part 20. intended use. Calibration procedures may be compilations
4.14-5
of published standard practices, manufacturers' instructions 4. The cconcentration of natural uranium, thorium that accompany purchased equipment, or procedures 230, radium-226, and lead-210 for stack effluent written in-house. Calibration procedures should identify the samples.
specific equipment or group of instruments to which the procedures apply. 5. The percentage of the appropriate 'concentration limit as shown in Table II oi Appendix B to 10
To the extent possible, calibration of measuring equip CFR Part 20.
ment should be performed using radionuclide standards certified by the National Bureau of Standards or standards 6. The estimated release rate of natural uranium, obtained from suppliers who participate in measurement thorium-230, radium-226, and lead-210 for stack assurance activities with the National Bureau of Standards effluent samples.
(see Regulatory Guide 4.15).
7. The flow rate of each stack.
Calibrations should be performed at regular intervals, at least semiannually, or at the manufacturer's suggested inter 7.1.2 Liquid Samples val, whichever is more frequent. Frequency of calibration should be based on the stability of the system. If appro For each liquid sample, the following should be recorded:
priate, equipment may be calibrated before and after use instead of at arbitrarily scheduled intervals. Equipment 1. Location of sample.
should be recalibrated or replaced after any repairs or when ever it is suspected of being out of adjustment, excessively 2. Type of sample (ground or surface water).
worn, or otherwise damaged and -not operating properly.
Functional tests, i.e., routine checks performed to demon 3. Date of sample collection.
strate that a given instrument is in working condition, may be performed using sources that are not certified by the 4. The concentrations of natural uranium, thorium-230,
National Bureau of Standards. radium-226, polonium-210, and lead-210. (If separate analyses were conducted for dissolved and suspended
6.3 Quality of Results radionuclides, report each result separately.)
A continuous program should be prepared and imple 7.1.3 Other Samples mented for ensuring the quality of results and for keeping random and systematic uncertainties to a minimum. The For other samples, the following should be recorded:
procedures should ensure that samples and measurements are obtained in a uniform manner and that samples are not 1. Location of sample.
changed prior to analysis because of handling or because of their storage environment. Tests should be applied to 2. Date of sample collection.
analytical processes, including duplicate analysis of selected effluent samples and periodic cross-check analyses with 3. Type of sample (vegetation, soil, radon-222 flux, independent laboratories (see Regulatory Guide 4.15). gamma exposure rate, etc.).
4. Analytical result (radionuclide concentration, gamma
7. RECORDING AND REPORTING RESULTS exposure rate, radon flux rate, etc.).
This section provides guidelines for recording all results. 7.1.4 ErrorEstimates Reports submitted to NRC should be prepared using these guidelines and the format shown in Table 3 of this guide. Reported results should always include estimates of uncertainty. The magnitude of the random error of the
7.1 Sampling and Analysis Results analysis to the 95% uncertainty level should be reported for each result. If significant, an estimate of the magnitude of
7.1.1 Air and Stack Samples the systematic error should also be reported.
For each air or stack sample, the following should be 7.2 Supplemental Information recorded:
The following information should be included in each I. Location of sample. monitoring report submitted to NRC:
2. Dates during which sample was collected. L. Name of facility, location, docket number, and license number.
3. The concentrations of natural uranium, thorium
230, radium-226, lead-210, and radon-222 for all 2. Description of sampling equipment and discussion of samples except stack samples. how sampling locations were chosen.
4.14-6
3. Description of sampling procedures, including sam Radon flux rates should be reported in picocuries per pling times, rates, and volumes. square meter per second. Stack flow rates should be reported in cubic meters per second. (In the International System of
4. Description of analytical procedures. Units, a curie equals 3.7 x 1010 becquerels, a microcurie equals 3.7 x 104 becquerels, and a milliliter equals 10-6
5. Description of calculational methods. cubic meters.)
6. Discussion of random and systematic error estimates, Estimates of random error should be reported in the including methods of calculation and sources of same units as the result itself. Estimates of systematic error systematic error. should be reported as a percentage of the result.
7. The values of the lower limits of detection, along Note: The Commission has discontinued the use in 10
with a description of the calculation of the lower CFR Part 20 of the 6pecial curie definitions for natural limit of detection. uranium and natural thorium (39 FR 23990, June 28,
1974). Reports to the Commission should use units con
8. The values of maximum permissible concentration sistent with this change.
from Table II of Appendix B to 10 CFR Part 20 used in any calculations. 7.4 Significant Figures
9. Discussion of the program for ensuring the quality of Results should not be reported with excessive significant results. figures, so that they appear more certain than they actually are. The reported estimate of error should contain no more
10. Description of calibration procedures. than two significant figures. The reported result itself should have the same number of decimal places as the II. Discussion of any unusual releases, including the reported error.
circumstances of the release and any data available on the quantities of radionuclides released. 7.5 Format
7.3 Units Reports should be submitted according to the format shown in Table 3.
Radionuclide quantities should be reported in curies.
Radionuclide concentrations should be reported in micro The term "not detected," "less than the lower limit of curies per milliliter for air and water, microcuries per gram detection (LLD)," or similar terms should never be used.
-' for soil and sediment, and microcuries per kilogram for Each reported result should be a value and its associated vegetation, food, or fish. Direct radiation exposure rates error estimate, including values less than the lower limit should be reported in milliroentgens per calendar quarter. of detection or less than zero.
4.14-7
TABLE 1 PREOPERATIONAL RADIOLOGICAL MOITORING PROGRAM FOR URANIUM HILLS
Type of Sample Sample Collection Sample Analysis Number Location Type of Method Frequency Frequency Analysis AIR
Particulates Three At or near the site Weekly filter change Quarterly composites Natural uranium, boundaries or more frequently of weekly samples Ra-226, Th-230,
as required by dust and Pb-210
loading One. At or close to the Continuous Weekly filter change Quarterly composites Natural uranium, nearest(b) residence(s) or more frequently as of weekly samples Ra-226, Th-230,
or occupiable offsite required by dust and Pb-210,
structure(s) (if with loading in 10 ke of site)
One -At a control or back COntinuous Weekly filter change Quarterly composites Natural urarviia, ground location remote or more frequently as of weekly samples Ra-226, Th-230,
from site(c) required by dust * and Pb-210
loading Radon Gas(d) Five or Same locations as for Continuous or Continuous Each sample Rn-222 more., air particulates at least one or continuous week per month representing
3 WATER
about the same period each month Ground Water(e) Six or Wells located around Grab more future tailings dis quarterly Quarterly Dissolved natural posal area. At least uranium, Ra-226, three wells hydrologi Th-230, Pb-210,
cally down gradient and Po-210
from disposal area. At least three located on other sides of tailings disposal area.(f)
One from Wells within 2 km of Grab each well tailings disposal area.
Quarterly Quarterly Dissolved and that are or could be used suspended natural for potable water supplies, uranium, Ra-226, watering of livestock, or Th-230, Pb-210,
crop irrigation. and Po-210
One Well located hydrologi Grab Quarterly cally up gradient from Quarterly Dissolved natural tailings disposal area uranium, Ra-226, to serve as control or Th-230, Pb-210,
background location. and Po-210
( ( (
K
TABLE 1 (Continued)
PREOPERATIONAL RADIOLOGICAL MONITORING PROGRAM FOR URANIUM MILLS
Type of Sample Sample Collection Saple Analysis Type of
.Number Location Method Frequency Frequency Analysis Surface Water(g) One from Large permanent onsite Grab Quarterly Quarterly Suspended and each body* water impoundments or aissoivea naLurat of water offsite impoundments uranium, Ra-226 that may be subject to and Th-230
direct surface drainage from potentially con taminated areas or that Semiannually Suspended and could be affected by a dissolved Pb-210
tailings impoundment and Po-210
failure.
Surface Water One from Surface waters passing Grab monthly Monthly Suspended and each body through the site(n) or dissolved natural of water offsite surface waters uranium, Ra-226, that may be subject to Th-230
drainage from potentially contaminated areas or that could be affected by a tail ings impoundment failure. Semiannually Suspended and dissolved Pb-210
and Po-210
VEGETATION,
'0 FOOD, AND FISH
Vegetation Three Grazing areas near the Grab Three times Three times Natural uranium, site in different sectors during grazing Ra-226, Th-230,
that will have the highest season Pb-210, and predicted air particulate Po-210
concentrations during milling operations.
Time of harvest Food Three of Crops, livestock, etc. Grab Once Natural uranfi um, each type raised within 3 km of or slaughter Ra-226, Th-230,
mill site Pb-210, and Po-210
Fish Each body Collection of fish (if Grab Semiannually Twice Natural urani um, of water any) from lakes, rivers, Ra-226, Th-230,
and streams in the site Pb-210, and Po-210
environs that may be subject to seepage or direct surface runoff from potentially con taienated areas or that could be affected by a tailings impoundment failure
TABLE 1 (Continued)
PREOPERATIONAL RADIOLOGICAL MONITORING PROGRAM FOR URANIUM MILLS
Type of Sample Sample Collection Sample Analysis Number Location Type of Method Frequency Frequency Analysis SOIL AND SEDIMENT
Surface Sotl(k) Up to 300-meter intervals to a Grab Once prior to Once All samples for forty distance of 1500 meters in site construction. Ra-226, 10% of each of 8 directions from Repeat for loca samples natural center of milling area tion disturbed by uranium, Th-230,
excavation, leveling, and Pb-210
or contouring Surface Soil Five or At same locations used Grab Once prior to Once Natural uranium, more for collection of air site construction Ra-226, Th-230, and particulate samples. Pb-210
Subsurfame Soil Five At center reference loca Grab Once prior to site Once Profile(I) Ra-226 (all samples)
tion and at distances of construction. Natural uranium,
750 meters in each of Repeat for locations Th-230, and Pb-210
4 directions. disturbed by con (one set of samples)
struction.
Sediment(O)
Two from Up and downstream of sur Grab Once following spring Twice Natural uranium, each face waters passing through runoff and late Ra-226, Th-230,
0 stream site or from offsite sur summer following and Pb-210
face waters that may be period of extended subject to direct runoff low flow from potentially contami nated areas or that could be affected by a tailings impoundment failure One from Onsite water impoundments Grab Once prior to site Once Natural uranium, each (lakes, ponds, etc), or off construction Ra-226, Th-230,
water site impoundments that may impound- be subject to direct surface and Pb-210
ment runoff from potentially
.contaminated areas or that could be affected by tailings impoundment failure DIRECT RADIATION Up to 150-meter intervals to eighty Once prior to site Once Gamma exposure rate, a distance of'1500 meters construction. Repeat using passive in each of 8 directions for areas disturbed integrating device from center of milling by site preparation such as TLD, pressurized area or at a point equidis or construction. ionization chamber, or tant from milling area(i)
properly calibrated and tailings disposal area.
portable survey instrument.
( ( (
TABLE 1 (Continued)
PREOPERATIONAL RADIOLOGICAL MONITORING PROGRAM FOR URANIUM MILLS
Type of Sample Sample Collection Sample Analysis Type of Number Location Method Frequency Frequency Analysis Five or At same locations used for Once prior to Once Gamma exposure ra te, more collection of particulate site construction using passive inte samples grating device, pres surized ionization chamber, or properly calibrated portable survey instrument.
RADON FLUX(n) Up to At center reference location One sample Each sample Radon-222 flux ten and at distances of 750 and during each of
1500 meters in each of 4 three months.
directions.
TABLE 2 OPERATIONAL RADIOLOGICAL MONITORING PROGRAM FOR URANIUM MILLS
Sample Collection Sample Analysis Type of Sample Type of Method Frequency Frequency Analysis Number Location STACKS
One for Yellowcake dryer Isokinetic quarterly Each sample Natural uranium, Particulates Th-230, Ra-226, and each stack and packaging stack(s) Pb-210 if not avail able from other sources.
Measure stack flow rate semiannually.
Natural uranium One for Other stacks Representa Semiannually Each sample Th-230, Ra-226, and Particulates tive grab each stack Pb-210. Measure stack flow.
AIR
Locations at or near Continuous(a) Weekly filter change, Quarterly composite, Natural uranium, Particulates Three or more frequently as by location, of Ra-226, Th-230,
the site boundaries and weekly samples and Pb-210
in different sectors required by dust that have the highest loading predicted conceotra tions of airborne t*3 particulates(b),
Quarterly composite, Natural uranium, One or At the nearest resi Continuous Weekly filter change, by location, of Ra-226, Th-230,
more dence(s) or occupiable or more frequently and Pb-210
as required by dust weekly samples structure(s)
loading Quarterly composite, Natural uranium, One Control Location(s)(c) Continuous Weekly filter change, Ra-226, Th-230,
or more frequently by location, of weekly somples and Pb-210
as required by dust loading Monthly Rn-222 Radon Gas Five or Same locations as for Continuous At least one week per more air particulates or at least calendar month repre one week (d) senting approximately per month the same period each month WATER
Hydrologically down Grab Monthly (first year) Monthly (first year) Dissolved natural Ground Water Three or Quarterly (after Quarterly (after first uranium, Ra-226, more gradient and rela Th-230, Pb-210,
first year) year)
tively close to the and Po-210(e)
tailings impoundment f)
Grab Quarterly Dissolved natural At least Hydrologically up Quarterly uranium, Ra-226, one con gradient (i.e., not Th-230, Pb-210
trol sample influenced by seepage and Po-210
from tailings)
( ( (
1\
TABLE 2 (Continued)
OPERATIONAL RADIOLOGICAL MONITORING PROGRAM FOR URANIUM MILLS
Type of Sample Sample Collection Sample Analysis Number Location Type of Method Frequency Frequency Analysis One from Each well used for Grab Quarterly Quarterly Dissolved and each well drinkina wat r or.
watering of live suspendea natural uranium, Ra-226, stock or crops within Th-230, Pb-210,
2 km of the tailings and Po-210
impoundment Surface Water Two from Surface waters passing Grab Quarterly Quarterly Dissolved and each water through the m111 site suspended natural body or offsite surface uranium, Ra-226, waters that are suffi Th-230, Pb-210,
ciently close to the and Po-210(g)
site to be subject to surface drainage from potentially contami nated areas or that could be influenced by seepage from the tail ings disposal area. (h)
4t One sample collected up stream of mill site and w~ one sample collected at the downstream site boundary or at a loca tion immediately down stream of location of potential influence One from Large water impound- Grab Quarterly Quarterly each water Dissolved and ments (i.e., lakes, suspended natural body reservoirs) near the uranium, Ra-226, mill site that are Th-230, Pb-210,
sufficiently close and Po-210
to the site to be sub ject to drainage from potentially contaminated areas or that could be influenced by seepage from the tailings disposal area.
VEGETATION, FOOD,
AND FISH
Vegetation Three or From animal grazing Grab or Forage(o) Three times during Each sample Ra-226.and Pb-210
more areas near the mill grazing season site in the direction of the highest predicted airborne radionuclide concentrations
TABLE 2 (Continued)
OPERATIONAL RADIOLOGICAL MONITORING PROGRAM FOR URANIUM MILLS
Type of Sample Sample Collection Sample Analysis Type of Number Location Method Frequency Frequency. Analysis Food Three of. Crops, livestock, etc. Grab Time of harvest Once Ra-226 and each type raised within 3 km of or slaughter Pb-210
mill site Fish Each body Collection of fish Grab Semiannually Twi ce Ra-226 of water (if any) from lakes, and Pb-210
rivers, and streams in the site environs that may be subject to seepage or direct surface runoff from potentially contami nated areas or that could be affected by a tailings impound ment failure SOIL AND SEDIMENT
Soil Five or Same as for Grab Annually Annually Natural uranium, more air partic Ra-226, and Pb-210
ulate samples"K)
Sediment One or Same as surface Grab Annually Annually Natural uranium, two from water samples(m) Th-230, Ra-226, each water and Pb-210
body DIRECT RADIATION Five or Same as for air Continuous Quarterly change Quarterly Gamma exposure more particulate samples passive in of passive dosim rate tegrating eters device
( ( (
Footnotes for Tables 1 and 2:
(a) Continuous collection means continuous sampler operation with filter change weekly or as required by dust loading, whichever is more frequent.
(b) The term "nearest" as used here means the location with the highest predicted airborne radionuclide concentrations during milling operations.
(c) Care should be taken in selection of the control sampling location so that it is representative of the site conditions. In general, a loca tion in the least prevalent wind direction from the site should provide a suitable location for a control sampling site.
(d) Various methods are acceptable; for example: (1) Continuous collection of a gaseous air sample with samples being changed about every
48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> for a 1-week period or (2) continuous sampling.
(e) If the sample contains appreciable suspended material, it should be filtered as soon as possible following collection through a membrane filter and the filtrate acidified to 1% hydrochloric acid.
Cf) The location of the ground-water sampling wells should be determined by a hydrological analysis of the potential movement of seepage from the tailings disposal area. In general, the objective is to place monitor wells in all directions around the tailings area with the emphasis on the down gradient locations.
(g) Surface-water samples to be analyzed for dissolved and suspended fractions should be filtered as soon as possible following collection through a membrane filter and the filtrate acidified to 1% hydrochloric acid.
(h) Natural drainage systems (dry washes) that carry surface runoff from the site following a precipitation event should be sampled following the event but at a frequency not greater than monthly.
(i) The milling area refers to the-area that includes ore storage pads, mill buildings, and other processing areas.
(j) Thermoluminescent dosimeters should contain two or more chips or otherwise provide for two readings per exposure period (see Regulatory Guide 4.13).
(k) Surface soil samples should be collected using a consistent technique to a depth of 5 cm.
.(1) Subsurface soil profile samples should be collected to a depth of one meter. Samples should be divided into three equal sections for analysis.
(m) Several samples should be collected at each location and composited for a representative. sample.
(n) Radon exhalation measurements should not be taken during periods when the ground is frozen or covered with ice or snow or following periods of rain. It is recommended that these measurements be taken in the spring through the fall during normal weather conditions.
(o) Vegetation or forage sampling need be carried out only if dose calculations indicate that the ingestion pathway from grazing animals is a potentially significant exposure pathway (an exposure pathway should be considered important if the predicted dose to an individual would exceed 5% of the applicable radiation protection standard).
TABLE 3 (a)
SAMPLE FORMAT FOR REPORTING MONITORING DATA
1. STACK SAMPLES
For each sample analyzed, report the following information:
a. Date sample was collected b. Location of sample collectjon C. Stack flow rate (mr/sec)
Cet*centration Error Estimate(b) Release Rate Error Estimate LLDWc Radionuclide 0(0ct/01) (jiCi/ol) (Ci/qr) (Ci/qr) (Pcil/ml) % MPC(c)
U-nat Th-230
Ra-226 Pb-210
2. AIR SAMPLES
For each sample analyzed, report the following information:
a. Date sample was collected b. Location-of sample collection Concentration Error Estimate LLO
Radionuclide (peC/ml) (cti/,1) (Wci/ml) % HPC
U-nat Th-230
Ra-226 Pb-210
Rn-222 (a)Thls table Illustrates format only. It is not a complete list of data to be reported. (See text of guide and Tables 1 and 2.)
(b)Error estimate should be calculated at 95% uncertainty level, based on all sources of random error, not merely counting error.
Significant systematic error should be reported separately. See Sections 6.1, 7.1.4, and 7.3.
(c)All calculations of lower limits of detection (LLD) and percentages of maximum permissible concentration (MPC) should be included as supplemental information.
( ( (
I"
TABLE 3 (Continued)
"SAMPLE FORMAT FOR REPORTING MONITORING DATA
3. LIQUID SAMPLES
For each sample analyzed, report the following information:
a. Date sample was collected b. Location of sample collection c. Type of sample(for example: surface, ground, drinking, stock, or irrigation)
Concentration Error Estimate LLD
Radionuclide . (pCi/ml) (pCffml) (uci/al)
U-nat (dissolved)
U-nat (suspended)(d)
Th-230 (dissolved)
Th-230 (suspended)(d)
Ra-226 (dissolved)
Ra-226 (suspended)(d)
Pb-210 (dissolved)
Pb-210 (suspended)(d)
Po-210 (dissolved)
Po-210 (suspended)(d)
4. VEGETATION, FOOD, AND FISH SNIPLES
For each sample analyzed, report the following Information:
a. Date sample was collected b. Location of sample collection c. Type of sample and portion analyzed Concentration Error Estimate LLD
Radionuclide (pCikg wet) (pCi/kg) (pCi/ko)
U-nat Th-230
Ra-226 Pb-210
(d)Not l1 samples must be analyzed for suspended radionuclides. See Sections 1.2 and 2.2 of this guide.
TABLE 3 (Continued)
SAMPLE FORMAT FOR REPORTING MONITORING DATA
5. SOIL AND SEDIMENT SAMPLES
For each sample analyzed, report the following information:
a. Date sample was collected b. Location of sample collection c. Type of sample and portion analyzed Concentration Error Estimate LLD
Radionuclide (pCi/g ) ,(iCi/g) (C i/q)
U-nat Th-230
Ra-226 Pb-210
6. DIRECT RADIATION MEASUREMENTS
For each measurement, report the dates covered by the measurement and the following information:
00 Exposure Rate Error Estimate Location (mR/qr) (mR/qr)
7. RADON FLUX MEASUREMENTS
For each measurement, report the dates covered by the measurement and the following information:
Flux Error Estimate Location (pCi/m 2 -sec) (pCi/m 2 -sec)
( ( (
BIBLIOGRAPHY
Harley, John H., editor, HASL Procedures Manual, HASL
ANSI N13.1-1969, "Guide to Sampling Airborne Radio
300, USERDA, revised annually.
active Materials in Nuclear Facilities," American National Standards Institute, Inc., 1430 Broadway, New York, Hyde, E.K., The Radiochemistry of Thorium, NAS-NS 3004, N.Y. 10018.
National Academy of Sciences-National Research Council,
1960.
ANSI N 13.8-1973, "Radiation Protection in Uranium Mines,"
American National Standards Institute, Inc., 1430 Broadway, Instrumentation for Environmental Monitoring, Lawrence New York, N.Y. 10018. Berkeley Laboratory, LBL-1, Vol. 3, updated periodically, Berkeley, California.
ANSI N14.10-1974, "Specification and Performance of Kirby, H.W., and M.L. Salutsky, The Radiochemistry of Onsite Instrumentation for Continuously Monitoring Radio Radium, NAS-NS 3057, National Academy of Sciences activity in Effluents," American National Standards Institute, National Research Council, 1964.
Inc., 1430 Broadway, New York, N.Y. 10018.
May, K. R., N. P. Pomeroy, and S. Hibbs, "Sampling Tech Cavallo, L.M. et al., "Needs for Radioactivity Standards and niques for Large Windborne Particles," Journal of Aerosol Measurements in Different Fields," NuclearInstruments and Science, Vol. 7, 1976, pp. 53-62.
Methods, Vol. 112, 1973, pp. 5-18.
McCurdy, D. E., K. J. Schiager, and E. D. Flack, "Thermo
"Environmental Radioactivity Surveillance Guide," ORP
luminescent Dosimetry for Personal Monitoring of Uranium SID-72-2, U.S. Environmental Protection Agency, Washing Miners," Health Physics, Vol. 17, 1969, pp. 415-422.
ton, D.C., 1972.
Methods for Air Sampling and Analysis, American Public
"Environmental Surveillance for Fuel Fabrication Plants,"
Health Association, Washington, D.C., 1977.
BNWL-1973, Battelle Pacific Northwest Laboratories, Richland, Washington, 1973.
Operational Health Physics, Proceedings of the Ninth Friedland, Stephen S. and Lyle Rathbun, "Radon Monitor Midyear Topical Symposium of the Health Physics Society, Central Rocky Mountain Chapter, Health Physics Society, ing: Uranium Mill Field Experience with a Passive Detector,"
presented to IEEE Nuclear Science Symposium, San P.O. Box 3229, Boulder, Colorado 80303, 1976.
Francisco, California, October 1979.
Percival, D.R., and D.B. Martin, "Sequential Determination of Radium-226, Radium-228, Actinium-227, and Thorium Fuchs, N. A., 'Sampling of Aerosols," A tmosphericEnviron ment, Vol. 9, 1975, pp. 697-707. Isotopes in Environmental and Process Waste Samples,"
Analytical Chemistry, Vol. 46, 1974, pp. 1742-1749.
George, A.C. and A.J. Breslin, "Measurements of Environ Radioassay Proceduresfor EnvironmentalSamples, 999-RH
mental Radon with Integrating Instruments," presented at
27, U.S. Public Health Service, Washington, D.C., 1967.
the Atomic Industrial Forum Uranium Mill Monitoring Workshop, Albuquerque, N.M., 1977.
Regulatory Guide 4.5, "Measurements of Radionuclides in the Environment-Sampling and Analysis of Plutonium in George, A.C., A.J. Breslin, and S.F. Guggenheim, "A Cumu Soil," USNRC, May 1974.
lative Environmental Radon Monitor," Proceedings of Ninth Midyear Health Physics SymposiumDenver, Colorado, 1976.
Regulatory Guide 4.13, "Performance, Testing, and Pro cedural Specifications for Thermoluminescence Dosimetry:
Gibson, W.M., The Radiochemistryfor Lead, NAS-NS 3040,
Environmental Applications," USNRC, July 1977.
National Academy of Sciences-National Research Council,
1961.
Regulatory Guide 4.15, "Quality Assurance for Radiolog Grindler, J.E., The Radlochemi.stry of Uranium, NAS-NS ical Monitoring Programs (Normal Operations)-Effluent Streams and the Environment," USNRC, December 1977.
3050, National Academy of Sciences-National Research Council, 1962.
Shearer, S.D., Jr., and C.W. Sill, "Evaluation of Atmospheric Radon in the Vicinity of Uranium Mill Tailings," Health
"A Guide for Environmental Radiological Surveillance at Physics, Vol. 17, 1969, pp. 77-88.
ERDA Installations," ERDA 77-24, Department of Energy, Washington, D.C., 1977.
Handbook of RadiochemicalAnalytical Methods, EPA-680/ Sill, C.W., "An Integrating Air Sampler for Determination of Radon-222," Health Physics, Vol. 16, 1969, pp. 371-377.
4-75-001, USEPA, 1975.
4.14-19
Sill, C.W., "Simultaneous Determination of U-238, U-234, Sill, C.W., "Separation and Radiochemical Determination Th-230, Ra-226, and Pb-210 in Uranium Ores, Dusts, and of Uranium and the Transuranium Elements Using Barium Mill Tailings," Health Physics, Vol. 33, 1977, pp. 393-404. Sulfate," Health Physics, Vol. 17, 1969, pp.89-107.
Sill, C.W., and C.P. Willis, "Radiochemical Determination Standard Methods for the Examination of Water and Waste of Lead-210 in Uranium Ores and Air Dusts," Analytical water,13th Edition, American Public Health Association, 1971.
Chemistry, Vol. 49, 1977, pp. 302-306.
Wedding, J.B., A.R. McFarland, and J.E. Cermak, "Large Sill, C.W., "Determination of Thorium and Uranium Particle Collection Characteristics of Ambient Aerosol Isotopes in Ores and Mill Tailings by Alpha Spectrometry," Samplers," Environmental Science and Technology, Vol. II,
Analytical Chemistry, Vol. 49, 1977, pp. 618-621. pp. 387-390, 1977.
Sill, C.W., et al., "Simultaneous Determination of Alpha Workshop on Methods for Measuring Radiation In and Emitting Nuclides of Radium Through Californium in Around Uranium Mills, Atomic Industrial Forum Program Soil," Analytical Chemistry, Vol. 46, 1974, pp. 1725-1737. Report, Vol. 3, No. 9, Atomic Industrial Forum, Inc.,
Washington, D.C., 1977.
Sill, C.W., and R.L. Williams, "Radiochemical Determina tion of Uranium and the Transuranium Elements in Process Wrenn, M.E. and H. Spitz, "Design of a Continuous Digital Solutions and Environmental Samples," Analytical Chemis Output Environmental Radon Monitor," IEEE Transactions try, Vol. 41, 1969, pp. 1624-1632. on Nuclear Science, NS-22, 1975.
- UA GOVERNMENT PRINTING OFFICE: 1980 620-269/90 1-3
4.14-20
APPENDIX
LOWER LIMIT OF DETECTION
For the purposes of this guide, the Lower Limit of Detec V is the sample volume (milliliters);
tion (LLD) is defined as the smallest concentration of radio active material sampled that has a 95% probability of being Y is the fractional radiochemical yield (when detected, with only a 5% probability that a blank sample applicable);
will yield a response interpreted to mean that radioactive material is present. (Radioactive material is "detected" if it is the radioactive decay constant for the yields an instrument response that leads the analyst to con particular radionuclide; and clude that activity above the system background is present.)
At is the elapsed time between sample collection For a particular measurement system (which may and counting.
include radiochemical separation):
The value of Sb used in the calculation of the LLD for a
4.66 Sb particular measurement system should be based on the LLD= actual observed variance of the instrument background
3.7 x 104 EVY exp(-,At) counting rate rather than an unverified theoretically predicted variance.
where Since the LLD is a function of sample volume, counting LLD is the lower limit of detection (microcuries efficiency, radiochemical yield, etc., it may vary for differ per milliliter); ent sampling and analysis pr6cedures. Whenever there is a significant change in the parameters of the measurement
"isthe standard deviation of the instrument system, the LLD should be recalculated.*
background counting rate (counts per second);
- For a more complete discussion of the LLD, see "HASL Proce
3.7 x 104 is the number of disintegrations per second per microcurie; dures Manual," John H. Harley, editor, USERDA, HASL-300 (revised annually) and Currie, L.A., "Limits for Qualitative Detection and Quantitative Determination-Application to Radlochemistry," AnaL
Chem. 40, 1968, pp. 586-93, and Donn, J. J. and R. L. Wo0ke, "The E is the counting efficiency (counts per disin Statistical Interpretation of Counting Data from Measurements of tegration); Low-Level Radioactivity," Health Physics, Vol. 32, 1977, pp. 1-14.
4.14-21
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