Regulatory Guide 8.21

Health Physics Surveys for Byproduct Material at NRC-Licensed Processing and Manufacturing Plants

ML13350A223
Person / Time
Issue date:	05/31/1978
From:	NRC/OSD
To:
References
RG-8.021
Download: ML13350A223 (11)

.... ..-:/-.I U.S. NUCLEAR REGULATORY

COMMISSION

May 1978 REGULATORY

GUIDE OFFICE OF STANDARDS

DEVELOPMENT

REGULATORY

GUIDE 8.21 HEALTH PHYSICS SURVEYS FOR BYPRODUCT

MATERIAL AT NRC-LICENSED

PROCESSING

AND MANUFACTURING

PLANTS

A. INTRODUCTION

Paragraph

20.201(b)

of 10 CFR Part 20. "Stand-ards for Protection Against Radiation," requires that each licensee make or cause to be made such surveys as may be necessary.for him to comply. with the regulations in Part 20. As used in Part 20, the term",survey" is defined as an evaluation or theradiation hazards incident to the production, use, release, dis-posal. or presence of radioactive materials or other sources of radiation under a specific sct of condi-tions. This guide identifies the types and frequencies of surveys that are acceptable to the NRC staff in plants licensed by the NRC for processing byproduct material or manufacturing such material for distribu-tion.

B. DISCUSSION

Surveys arc considered to be part of a 9-pretio, sive protection program established by according to the philosophy and principl c.f Regula-tory Guide 8.10, "Operating Philosophy f "Z ain-taining Occupational Radiat' Exposures As Low As Is Reasonably Achievab niciplcs, methods, and instrumentation for c radiation.and con-*tamination survr er ev f6ped early in the atomic energy togra n ave been discussed in reports ofj l ronal, ouneiI on Radiation Protec-tion ana ea CRP) (Refs. 1-3), the In-ternation bomic znergy Agency. (IAEA) (Refs.4-8), and t jternational Commission on Radiolog-ical Protectioe"(Ref.

9). The health physics literature NRC-licensed processing and manufacturing plants are re-ferred to in this guide as "'manufacturing plants.'" contains abundant information for use itn establishing radiation survey programs and selecting appropriate methods, procedures.

and equipment for their im-plementation (Refs. 3. 5. and 6).Surveys'.

arc a necessary personnel monitoring, which mn.asures indiVidtltal r`tion ex-posures with devices worn b.I.lhe orkers'Refs.

3.5. 6. 8. and 9). ... ..... ., C. REGULATORY

POSITION Min this guide are accept-ableýfiithe stuiff for estahlishing acceptable sur-vey pr grams,.In accordance with thie as hlw as isachievable (ALARA) philosophy. -Man-iffacttrs licensed by the NRC should have, a health p'h sics staff capable of developing and implementing.survey programs as described below.I. Types of Surveys I. I General Description Surveys performed in compliance with §20.201 of 10 CFR Part 20 should include those necessary to evaluate external cxposurC It) personnel, concentra- tions of airborne radioactive materials in the facility, surface contamination levels, and radioactive IThe word "survey." often used synonynmtusly with survcil.lancc." ."monitoring.'" tr "'area monitoring." is uscd in this guide to connote the personal inspeclion of various localions in a facility using radioactive materials.

with or without ,accompanying measurements, to determine the cfreetivenes', ot' o islures hit pln-tect against radiation.

• USNRC REGULATORY

GUIDES Cam-nint Shoulef tw soit to the SICrlov 411 1t t1,*- ,inUS Nui~a, 0,9.111111tu1i'y G.uides Ato sued to duictbe and maeksAai'ebk toathePu.blmicMthodt Uses' Cowmmission.

Withm~nqtn, DC. 2055b. Atl~.. -D-,h#I,., ."dl S.-..OccuW" 1). thi eNttC stitaff of W10mentin

101ii PaSS of the Carrnno':

lnv%,regttoi Wm t delineaster I dchn Owes used by the rto I n sivalus ist;f solicit icproblems

7 b*e gu ies s Jo' .ii~swp'd sa n I h!- 1.t el tp ig hen I y rmddiI~ ellanI" or postitulted ticcidIlets.

of to pIowde-guidarics to applicants.

eoglulatory Guides we not %.bulisteit ltr rostlations.

and wmoplianol Whith I h" it not, raqisre'd.

1. Powese fr.'.,rso

6. Peiwc%tJi Melthods NOi 2olutioiti dl'lser" tralm those 101 out so the guides *.lt be atiecti. 2. Rihevc.anrt Jl est Rteactuos

7.eWe it they Provide a beitirefar the lintlngt rectuittiipto the ritesrtietof conlmnuanco, 3. 8utaeulr.tae~.tBOei.~.e HAtth of 0 Permit of. lice Ns by thes Commeunnsr..

4. £nvtoni~nIOjl al .1Saiten I Anti, .it l4--5. Mateseal en Plans Proecticon

10. C-,-Ji catritneth ands tel'OnI for improvemmeitis in thewe guides seaencouraged at oil teterm, &Zd guides Wilt be revisades seploatijtte.

to ecctrmmtodsare commnents and Attluetlitfarf single Mileee at illutl Qetlest 1with"sy 1w r1'.udwr I t ir t itau r~to #1ffed n~ew infomation of experience.

Howeeee. comnments an this guade,il me~tl on an automatic.

distlributionit tin utops s enqt" n.. '11 lseIt~i'lf tr ra=6*d wlithin abf't two MAoiPte allits i busnCit. will bt fie ttCuIVY t~lyuefl ini divtision tiiutld tie mado in witeing to the US. Nintee tsl Vil~lo COMIn'ts1ei,.

evaluatinig the need for en seaty rewleion.

WAh~naltint.

0C. M055. Atlentsin- O.'ect, ...... ..or It 0ftj,ts'en Cipot, effluents from the facility.

Environmental monitorinj of effluents is beyond the scope of thi!guide.1 Radiation protection programs should include the types of surveys discusscd below.1.2 Surveys or External Radiation Exposure Levels in Restricted Areas Radiation safety personnel'

should survey loca-tions where individuals may be exposed to radiation intensities that might result in radiation doses in ex-cess of 10 percent of the limits of paragraph 20. 101(a) of 10 CFR Part 20 in any calendar quartet or where an individual is working with any unshieldcc sot'ce that produces a gamma or beta dose rate ex.ceeding I mrad/h at I meter.Preoperational.

routine, and special surveys of these areas should be performed by the radiation pro-tection staff as described in Section C.2 of this guide.Results of these surveys should be recorded as de-scribed in Section C.3. In addition, workers should monitor themselves if they are exposed to external radiation levels that could exceed any of the limits of paragraph

20.101(a).

These surveys by workers should consist of periodic instrument surveys during work with radioactive materials.

Workers should be properly trained to conduct such surveys.Surveys are not acceptable for routine compliance with the personnel monitoring requirements of§20.202. However, in the event of accidental loss of personnel dc.,imcttry data. e.g.. as a result of losing the dosimeter or chemical or physical damage to the dosimeter, the best alternative means of estimating the exposure may be to use survey data in conjunc-tion with appropriate occupancy factors. In such case, the estimate, including the survey data used.should be documented and retained indefinitely (see paragraph

20.401(c)(2)(ii)).

Survey results supple-ment personnel monitoring, when it is required, and tlhcy should be reviewed carefully by the Radiation Safety Officer in conjunction with personnel monitor-ing records to identify potentially hazardous situa-tions and to ensure that all personnel are adequately monitored.

1.3 Measurements of Radioactive Material Con-centrations in Air The radiation safety staff should perform mcas-I However. the radiation safety program should include surveys or records that indicate control of the quantities of radioactive ma-terial released in air and water to unrestricted areas, as required b)10 CFR Part 20.4 Reference to radiation safety staff or personnel in this guide is not intended to indicate that such staff necessarily consists ol more ihan one person designated as responsible for radiation safety, The size and qualifications of the staff depend on the scope and kind of manufacturing activities involving radioactive materials.

urements of radioactive material concentrations in air, at frequencies specified in Section C.2 of this guide, for areas where operations could expose work-ers to the inhalation of quantities of radioactive mate-* rial exceeding those specified in paragraph 20. 103(b)(2).

Special requirements for such monitor-ing may also be made a condition of the license.Air samples collected should be representative of the air in the workers' breathing zone. However,-when obtaining representative samples from the breathing zone is not practicable, the samples should be obtained frotm a location at which the radioactivity concentration in air is known to be greater than that of the workers' breathing zone. For example. sam-pies taken outside the breathing zone are acceptable if the sampler head is located so that the concentration of radioactive material in air at the location of the sampler head is equal to or greater than the concen-tration in the breathing zone.When measuring the quantity of radioactive mate-rial deposited on or in an air sample filter, the radia-tion safety staff should include appropriate correc-tiotiq for alpha or beta absorption by the filter media and by material collected on the filter. Filter media used for the collection of alpha emitters should retain collected material on the filtcr surface. Overestimates of the volume of air that has passed through the filter should be avoided by means of accurate calibration of the flow rate and by preventing or correcting for the loss of flow due to the accumulation of material on the filter.Breathing zone or general air sampling should be cor.ducted while work is in progress unless the results of continuous sampling verify that the concentration of radioactive material in the breathing zone is not likely to exceed 25 percent of the values given in 10 CFR Part 20, Appendix B. Table I. Column i. The use of personal (lapel) samplers is acceptable for con-tinuous air sampling.

The air sampling frequency, if not continuous, and the times selected for sampling should be based on the nature of the manufacturing process involved and the probability that airborne radioactive material will be present. When assessing this probability is difficult, frequencies based on in-formation given in Section C.2 and Table I of this guide are acceptable.

An air monitors may be needed to provide a warn-ing signal that the concentration of airborne radioac-tivity has become unexpectedly high. For each room or area where radioactive material is handled, the licensee should perform an analysis to determine whether an air monitor is necessary.

Each analysis I The term "air monitor" as used here refers to a device pro-viding an air or particle collection system, a radiometric meas-urement system, a continuous recorder, a meter with preset alarm capability, and an audible alarm system.8.21-2*1 should be kept available for inspection." An air monitor should be provided if the analysis indicates that it is likely that, before the air monitor alarm is actuated, accidental conditions could cause an intake of radioactive material exceeding the intake that would result from inhaling such material for 4() hours at the concentrations specified in 10 CFR Part 20.Appendix B, Table I. Column 1.1 Workers should recognize that the principal func-tion of an air monitor is to alert personnel to take immediate action to protect themselves from expo-sure to the unexpected release of airborne radioactive material.

Inhalation exposures are in progress during the time between the release of the radioactive mate-rial and the sounding of the alarm. Thus, every rea-sonable effort should be taken to minimize this time period. In particular, the air inlet of the monitor should be located near the potential source of air-borne radionuelides, preferably between the source and the workers. The use of long tubing or piping leading to the inlet should be avoided because of the high probability of alarm delay due to radionuclide deposition on the interior walls of the tube or pipe.The dose to personnel may be reduced by selecting a low activity level setpoint for the alarm: however.this may result in false alarms that weaken the work-ers' confidence in the monitor. These alternatives should be balanced io maximize safety.The dose to personnel may also be reduced by pro-viding a high flow rate of air through the detection chamber or filter. A device such as a limiting orifice that is intended to provide a constant flow rate should not be used with an air monitor because it is more important to maximize the volume of air drawn through the filter, thus reducing the time of exposure before the alarm by using a higher flow rate, than to measure the concentration accurately.

1.4 Surface Contamination Surveys Routine monitoring for radioactive contamination that could be present on surfaces of floors. walls, laboratory furniture, and equipment is a necessary part of the survey program. Failure to control surface contamination may result in unnecessary external or internal exposure of personnel to radiation.

Although external radiation levels from radioactive contamina- tion may at times be hazardous, the primary concern is to avoid internal exposure resulting from the intake of loose radioactive material by inhalation, ingestion.

or skin absorption.

1.4.1 Removable Contamination For the purpose of this guide. "removable con-tamination" is that fraction of the contamination

6 Applicants should either provide thc name of the manufacturer and model number of the air monitor to be used or a copy of the analysis that verifies that an air monitor is not required.To determine the quantity of radioactive material associated with this 40-hour exposure.

multiply the concentration value specified in Appendix B to 10 CFR Part 20 by 4.8 x 10' mi.present on a surface that can be transferred to a smear test paper by rubbing with moderalc prcsture.

Con-siderable information is available to aid radiation pro.tection personnel in the selection and use of' ir:stru-ments for performing surlface contamination surveys appropriate to the radionuclides involved in manufac-turing plants (ReIs. I-10).Methods and instruments used in surface con-lamination surveys should be sufficiently sensitive it)detect the nucl;des being monitored.

Also. uniform methods for collecting and analting smear sample:.should he used over extended periods to time in order to evaluate trends. Counting equipment used to analyze radioactive contamination on smear samples should he properly calibrated and rnaintaii.ad and should be capable of detecting the radiation from the smears. For example. smears containing how-energy radiation emitters (e.g.. H-3. C-14. 1-125) should he analyzed with liquid scintillation or internal propor-tional counters.

Check or calibration should be counted with each batch of smear samples.The collection tif smear samples should gener-ally be preceded by a rapid overall surveyv with a portable.

thin, end-window detector in order io a. Ensure that gross contamination levels are not already too high for counting in sensitive equipment.

b. Minimize the chance for inadvertent spread tol contamination- by the smear survey or other activities to be performed in the meantime, and c. Determine which areas require greater atten-tion in smear testing.The instrument used should have a readout system with a short time constant and should be equipped with earphones or an external speaker system.A standardized method for smear testing of a relatively uniform area should he used to aid in com-paring contamination at different times and places. A dry smear taken from an area of about 100 cnm- is acceptable to indicate levels of removable contamina- tion.A diagram of each routinely surveyed area should be used for recording survey results. This pro-cedurc will provide radiation safety personnel wilh a method for identifying trends as well as satisfying regulatory requirements for survey records. The sur-veyor will find it helpful to specify key locations ton the survey diagram that are smear-tested at each sui-vcy and also to provide a space reminding the recorder to include: a. Contamination levels converted t) radioactiv- ity units in terms of equivalent alpha. beta, or gamma emission per unit area, in units specified in 10 CFR Part 20.b. The make and model number of instruments used in the survey and in counting the smear samples.0 8.21-3 c. The disintegration rate of each sample, d. The background count.e. All counting times, and f. The name and date of the person making the evaluation and recording the results.Provision should also be made on the diagram for recording an instrument check with an appropriate check or calibration source.The surveys discussed above are regularly scheduled, conducted by radiation safety personnel, and recorded on the survey diagrams.

In addition.more frequent.

informal radiation surveys should be conducted by the radiation workers themselves;

they need not be recorded.

For example. a contamination survey can be made by collecting a smear sample and holding it against a thin (less than 2 mg/cm-) end-window detector while the detector is in an area where radiation levels are less than about 0.05 mrem/h. At these levels, any appreciable surface con-tamination can be detected by simply holding the de-tector in a fixed position and moving the smear sam-ple close to and away from the detector several times and noting the meter readings.

This method may be used for the majority of radionuclides processed in manufacturing plants (excluding alpha and very low-energy beta emitters).

Part 20 of 10 CFR d=oes not specify limits for surface contamination.

Each applicant may propose and justify what removable surface contamination limits will be allowable before decontamination will be performed in each work area. These limits should be based on the need to avoid transfer of significant amounts of contamination to unrestricted areas and to maintain exposures as low as is reasonably achieva-ble. The contamination limits for restricted areas pre-sented in Table 2 of this guide are acceptable to the NRC staff and may be used without justification by the applicant.

1.4.2 Fixed Contamination For the purposes of this guide, "fixed contami-nation" is defined as radioactivity remaining on a surface after repeated decontamination attempts fail to significantly reduce the contamination level. Since most detectors respond to both removable and fixed contamination, limits should be based on total con-tamination.

A total contamination survey, using in-struments suitable for the radionuclides involved.should be conducted simultaneously with each re-movable contamination survey. The applicant may propose and justify what total contamination limits will be allowable for both restricted and in-plant un-restricted areas before decontamination will be per-formed. The limits appearing on line 2 of Table 2, multiplied by a factor of 5. are acceptable to the NRC staff and may be used without justification by the ap-plicant.1.5 Protective Clothing and Equipment Contami-nation Surveys Individuals working in areas where a potential for skin or clothing contamination exists should be pro-vided with suitable protective clothing.

If respiratory protective equipment is needed to prolect against in-halation of airborne radioactivity, the equipment should be used according to the instructions in Regu-latory Guide 8.15. "Acceptable Programs for Res-piratory Protection." Section 20.103 of 10 CFR Part 20 specifies monitoring requirements when protection factors are assumed to be provided by the use of res-piratory protection devices.Protective clothing and equipment should he sur-veyed for contamination before the worker leaves the restricted area. Since airborne radioactivity from con-taminated protective clothing is likely to be produced by dislodging any absorbed radioactive particles dur-ing removal, fixed station monitors should also be available in clothing change areas to survey clothing before it is removed. In addition, suitable areas should be provided for surveying protective clothing and equipment before storing them for further use or for decontamination and laundering.

When protective clothing contamination levels ex-ceed preselected limits, workers should be instructed to take care to avoid dispersal of contamination and to report the situation to the Radiation Sat'cty Office.A member of the radiation safety staff should then survey and supervise any necessary decontamination or clothing disposal.

The applicant may propose and justify protective clothing contamination limits con-sidered adequate for each restricted area; the limits given on line 4 of Table 2 are acceptable to the NRC staff for use without justification by the applicant.

Contamination levels observed and procedures fol-lowed for incidents requiring special surveys and de-contamination should be recorded.

The record should include the names of persons surveyed, a description of prior work activities, the probable causes, steps taken to reduce future incidence of contamination.

times and dates, and the surveyor's signature.

This information may be entered in a logbook. Individtial worker surveys of themselves need not be recorded unless the limits on line 3 of Table 2 are exceeded.However, the radiation safety staff should maintain daily surveillance to ensure that the workers continue their own personal contamination surveys. Results of radiation safety surveillance should be recorded.In restricted areas with little potential for surface contamination, personal clothing is often worn be-neath protective clothing.

Such personal clothing should be surveyed by the wearer before he or she leaves the restricted area. (However, this is neither U[.21-4

.I practicable nor necessary for employees working with only submicrocurie quantities of tritium or carhon-14.) When personal clothing contamination levels ex-ceed preselected limits. workers should be instructed to report the situation to the Radiation Safety Office.A member of the radiation safety staff should then survey and supervise any necessary decontamination or clothing disposal.

The applicant may propose and justify personal clothing contaminatio-i limits; the limits given on line 3 of Table 2 arc acceptable to the NRC staff and need not be justified by the anplicant.

Records should be maintained in the same manner as those for protective clothing contamination.

For individuals whose work is conducted in re-stricted areas with a potential for high surface con-lamination levels, complete clothing changes are normally provided.

In this case, personal clothing should be stored outside the restricted area. Surveys of personal clothing are not necessary, provided the area in which the clothing is stored is surveyed as discussed in Section C. I.4 of this guide and the sur-vey results are below the limits adopted ror in-plant unrestricted areas. Particular attention should be paid to surveying the body. hair. bottoms of the shoes or feet. and the hands after removal of protective cloth-ing and to washing before donning personal clothing.1.6 Personal Surveys Individuals whose duties require work in restricted areas where radioactive contamination of body sur-faces is probable should also survey all exposed areas of the body after showering and before donning per-sonal clothing or leaving the restricted area. Workers should be required to report the detection of contami-nation on the body to the Radiation Safety Office.Decontamination attempts, under the direction of Radiation Safety Office personnel or a medical con-sultant, should be repeated until (I) such attempts cease to effect significant reductions or (2) such at-tempts threaten to damage the skin.' When decon-tamination attempts are terminated, there should be no further concern if the residual contamination does not exceed preslected levels since the contamination would no longer present a significant ingestion hazard. Such levels may be proposed and justified by the applicant:

the limits given on line 5 of Table 2 are acceptable to the NRC staff and need not be justified by the applicant.

If residual contamination exceeds the selected limits, the affected individual should be released but periodic surveys should be made until the limits are no longer exceeded.

The resulting dose should be determined and entered in the individual's

0 Decontamination attempts without the licensee'*

medical con-sultant present should be restricted to washing with mild soap and water or it) decontamination procedures previously agreed upon by the medical consultant.

If such attempts do not reduce the con-lamination to acceptable levels. the aid of a physician should he obtained.personnel dosimetry reco rd. Complete records should be maintained (if each incident of this nature.Since manufacturing plants often process 1;.rge quantities of radioactive material.

bioassay progratns may be required.

Acceptahle features of such pro-grams arc published in Regulatory Guides X.9."Acceptable Concepts.

Models. Equations.

and As-sumptions for a Bioassay Prgram.'" and M. I I. "'Ap-plications of Bioassay forI Uranium.'" or issued by the Radioisotopes Licensing Branch.1.7 Surveys of Equipment Prior to Release to Un-restricted Areas Surface contamination:.

Ntrcys should be con-dueled for both removable and fixed contamination before potentially contamiatated equipment is released from restricted to unrestr:Ltcd areas. If contamination is detected, decontamination procedures should be repeated until additional efforts do not significantly reduce contamination levels. The applicant may pro-pose and justify total and removable contamination limits below which uncontrolled release of equipment is permitted.

The limits given for unrestricted areas on line I of Table 2 are acceptable to the NRC staff and need not be justified by the applicant.

1.8 Drinking WVaier Although it is highly unlikely that significant internal exposures will result from ingesting drinking water near worl. areas (Ref. 4). any water fountains in these areas should be smear-tested regularly, and the water should be sampled and analyzed at least quarterly.

Also. surveillance should be included in the radiation safety program to ensure that workers observe rules to prevent ingestion tof radionuc;ides.

e.g.. rules pertaining to eating. drinking, or smoking in work areas or while wearing potentially contami-nated clothing, storing foods in work areas, or pipet-ting by mouth.1.9 Surveys of Packages Received and Packages Prepared for Shipment External radiation surveys and smear tests of ex-ternal surfaces of packages received or packaged lfor shipment should be carried out near the receiving or packaging point to avoid inwarranted radiation expo-sures and inadvertent contamination of personnel or the facility.

Surveys and required labeling must com-ply with regulatory requirements (see §§20.205.32.19. and 32.70 through 32.74 of 10 CFR) and specific license conditions.

Delivery of packages within the plant should also he monitored when car-ried by personnel rather than mechanical conveyors.

Surveys should be made to determine when carts rather than hand carrying should be used. Packages containing significant amounts of radioactive mate-rials should not be surveyed or opened until the con-tainers have been placed in the appropriate protective

8.21-5 facility such as a radiological-type fumne hood or hot cell.No packages should be released for shipment or transfer to tither users unless contamination levels of internal sources or devices have been tested and cer-tified to meet the criteria of paragraph

35. 14(b)(5) for Group VI products or license conditions for other products as provided in §35.14 or in the manufac-turer's license. Also. no packages may be released for shipment or transfer when external radiation or surface contamination levels exceed limits set by the Department ot Transportation in Title 49 of the Code of Federal Regulations.

Ext,.rnal radiatiin and con-tamination levels should be maintained ALARA.I. 10 Checks on Posting of Caution Signs, Labels, Signals, Controls, and Notices to Employees The radiation safety staff should perform surveil-lance at least weekly to ensure that signs. labels, sig-nals. other access controls.

and required Notices to Employees.

copies o0 licenses, and tither items are properly posted. legible, and operative, as required by 10 CFR Parts l0 and 20 or license conditions.

Radiation alarm signals and access controls should be tested to verify proper operation under both the nor-mal and abnormal conditions that might be expected t) occur. Care should he taken to minimize exposure to) personnel who are conductin.

the tests. Any signs.labels, or notices found ito be missing should be promptly replaced.

Temporary signs. signal-. or bar-riers logether with appropriate worker notification and instruction may be used in the interim when items as specified in 10 CI-R Parts 19 and 20 are not available, hut acceptable corrections should be pro-vided as soon as practicable.

1. II Leak Tests of Sources Leak testing of sealed sources must be carried out in accordance with the terms and conditions of the manufacturer's materials license. Also. as provided in paragraph

35.14(b)(5).

sealed sources containing a. More than 100 microcuries of a byproduct ma-ierial with a half-life of more than 30 days (except iridium-192 seeds encased in nylon ribbon) or b. More than 10 microcuries of an alpha emitter must be leak tested for contaminalion or leakage at interv'als not to exceed 6 months unless a different interval is specified for a particular manufactured source under the provisions of paragraph

32.74(b).Further provisions and exceptions to leak-testing re-quirements are established in paragraphs

35.14(b)and 35.14(c)( I ).I. 12 Calibration of Radiation Safety Instruments Portable survey instruments should be calibrated to within =20 percent at a minimum of two points neir the lower 25 percent and upper 25 percent readings of each scale in order to examine readability.

operabil-ity. and accuracy.

Each source used for calibration should be certified by the supplier as recommended by the International CUMmission on Radiological Units and Measurements (Ref. II) and .,nould be cor-rected for decay as of the day on which the source is used for survey instrument calibration.

All decay cor-rections should be included in the radiation safety records system. A posted graph for each source is convenient, helpful in avoiding calculational errors.easily available for inspection, and acceptable for ob-taining source intensity within the required accuracy.Survey instrument maintenance and calibration should be performed at least annually.

Also. a calih-ration verification in an appropriate radiation field for at least one point near the midrange of each scale in use and a battery check are necessary at least as often as every 3 months in order to ensure the accuracy and operability of portable radiation survey instruments.

In addition, long-half-life

onslancy check sources should be used to check the continued accuracy of all instruments each time they are used.1.13 Surveys of Protective Clothing Before and After Laundering All garments with contamination levels exceeding tht,-, g.ven on line 3 of Table 2 should be either dis-pwed ,4, as radioactive waste or properly surveyed.packaged.

and labeled and sent to a laundry licensed to process and handle radioactively contaminated clothing.Each garment returned from a licensed laundry should be monitored before use. If contamination levels on the garment exceed those given on line 4 of Table 2. the garment should not be used.1. 14 Ventilation Surveys Radiation safety personnel should conduct surveys monthly (or more frequently)

to determine the face velocity of air at the entrance of radiological-type fume hoods in use to protect workers against the hazards from unencapsulated radioactive materials.4 Such measurements should be made by using a prop-erly calibrated thermoanemometcr or velometer to de-termine whether the airflow has been reduced to un-acceptable levels by filter loading or the malfunction of blowers, fans, etc. The minimum average face velocity for a fume hood with the sash in the operat-ing position or for an opening in a special enclosure should be 150 ftlmin. as determined from at least five different measurement points.Corrective action should be taken as soon as possi-ble when the face velocity is found to be deficient.

Work should be terminated if the average face veloc-ity falls below 100 ft/min.Where filtered exhausts are employed, devices such as U-tube manometers or the equivalent sho~uld be pr(vided to indicate the pressure drop across the filters. thus affording an early indication of airflow loss at cnctioures.

'4 I I 8.21-6 In addition to these surveys. each enclosure should be equipped with a device that measures pressure drop across the hood filter. Workers should be in-structed to maintain daily checks of these devices and to notify radiation safety personnel when the pressure drop exceeds a preset level.A thermoanemometer or velometer should be used at least semiannually to determine the number of air changes per hour provided by the ventilation system in each room in which work with uncncapsulated radioactive materials is conducted.

A minimum of six changes per hiur should be provided.1. 15 Surveys in In-Plant Unrestricted Areas Unrestricted areas should be surveyed periodically to ensure that radiation and radioactive material are adequately confined in restricted areas, except in cases where these materials must be transported be-tween areas. Such transportation should be surveyed or planned with the radiation safety staff.1. 15.1 Surface Contamination Surveys Removable surface contamination surveys in un-restricted areas should be performed and recorded at frequencies consistent with the potential for spread-ing contamination but not less frequently than quar-terly. With the exception of lunch rooms and snack bars, random smear testing of floors and furniture is adequate.

In lunch rooms and snack bars. equipment should also be surveyed.

If such surveys reveal that radioactive contamination is being transferred out of restricted areas, immediate corrective action should be taken to eliminate such transfers, and decontami- nation efforts in the unrestricted areas should be re-peated until it is evident that subsequent efforts would not significantly reduce contamination levels.If contamination is found in unrestricted areas, sur-veys should be performed on a more frequent sched-ule as necessary until the source of contamination is ascertained and corrected.

The applicant may propose contamination levels. following decontamination ef-forts described above, for in-plant unrestricted areas.The limits given on line I of Table 2 are acceptable to the NRC staff and need not be justified by the applicant.

1.15.2 Radiation Surveys Radiation surveys in unrestrictcd areas should be performed and recorded at frequencies consistent with the types and quantities of materials in use but not less frequently than quarterly.

These surveys should be made in areas adjacent to restricted areas and in all areas through which byproduct materials are transferred and temporarily stored before ship-ment. Dose rates in these areas shctld be evaluated to determine whether they comply with the require-ments of §20.105 of 10 CFR.1. 16 Surveillance

1. 16.1 Surveillance by Individual Performing Surveys The term "surveillance." as used in this sec.tion. refers it) observations of radiological

,,orking conditions in restricted areas made by the person ,.lho performs the routine radiation and contamination sur-veys. Such surveillance, one of the most important aspects of a radiation protection program. allows health physics personnel to acquire detailed knol-edge of each operation in order t) (1) identify wavs of preventing or minimizing exposures.

(2) select ap-propriate times for making health physics .n .i.as-urements.

and (3) adequately prepare for emergency conditions.

Health physics personnel .hould he suffi-ciently familiar with each operation to explain it in detail, to describe potential hazards and the precau-tions taken to minimize exposures.

and to discuss how this knowledge of the operation has influenced the selection of appropriate times for performing health physics measurements.

1.16.2 Regular Inventory of Radioactive Material.Audit of Procedures,.

and Instruction of Personnel The surveillance program inc'udes: a. Regular inventory of radioactive materials and their locations.

b. Frequent audits of radiation safely procedures and the uses and amounts of material in process com-pared to licensed possession limits, and c. Discussions with personnel to ensure their continued awareness ot safety procedures and the ap.propriateness of their instruction and training for the tasks they are performing.

These surveillance activities may be condu.tcd during the performance of other survey measurements or tests. The radiation safety staff should conduct surveillance inspections in a manufacturing plant at least weekly. The surveillance should be perf'ormed at least annually by the Radiation Safety Officer in the presence of a management representative such as the plant manager to provide management with an awareness of the nature and importance of activities conducted for personnel protection and plant safety.2. Frequency of Surveys The frequency of routine surveys depends on the nature. quantity, and use of radioactive material%, as well as the specific protective facilities, equipment.

and procedures that are designed to protect the worker from external and internal exposure.Generally.

surveys should be performed before radioactive materials are used in a new facility in order to establish a baseline of background radiation levels and radioactivity from natural sources, struc-tural components of the facility (including radon and 8.21-7 thoron emanation rates and concentrations), and any already existing operations with radiation sources in nearby rooms or facilities.

These baseline surveys should be performed under the various conditions of containment, shielding design, and process heat loads to be expected under manufacturing conditions.

Sur-veys of simulated process operations with nonradioactive reagents or smaller amounts of radioactive material should also be performed where appropriate to establish the performance of protective equipment and procedures before full-scale produc-tion using any new or untested facilities or processes.

Surveys should be repeated as soon as process op-erations begin with normal levels of radioactive mate-rial and with all potentially exposed workers present and conducting their job functions.

Surveys should also be conducted after any significant changes in the conditions that existed at the time of the most recent survey, including changes in the quantities of radioactive material handled or in protective equip-ment and procedures.

Routine and repetitive surveys are necessary to control the location of radioactive materials within handlingsystems and to ensure the continued integ-rity of protective equipment and procedures.

Surveys are also necessary for procedures in which sealed sources are handled outside shielded containers.

For operations involving materials in gas. liquid, or finely divided forms, the survey program should be designed to monitor the continued adequacy of con-tainment and control of the materials involved.The minimum acceptable frequencies of surveys for manufacturing plants are given in Table I. The NRC staff considers the frequencies established in Table I to meet the requirements of §20.101 of 10 CFR.3. Records of Surveys Reference should be made to §§20.401 and 30.51 and Parts 31-35 of 10 CFR for rccordkeeping re-quirements regarding surveys related to the receipt, use, packaging, transfer, export, and disposal of by-product materia'l.

The regulation in §20.401 requires that licensees maintain records in the same units used in Part 20. Thus, external exposure rates should be recorded in estimated maximum dose equivalent units to relevant parts of the body as specified in 10 CFR Part 20. Air concentration measurement results in units of j.Ci/ml and surface contamination measure-ment results in units of dpm/l00 cm 2 or .Ci/100 cm 2 (or as in §20.5) should be recorded.Record retention requirements are given in the reg-ulations cited abov

e. Paragraph

20.401(c)(2)

requires that survey records be preserved for 2 years, except that records of air monitoring and (in the absence of personnel monitoring data) records of surveys to de-termine external radiation dose are to be maintained until the NRC authorizes their disposition.

Records may be maintained in logbooks or on spe-cial forms as long as they are clear, legible, under-standable.

and authenticated by authorized personnel.

The signature of the person making the record and the date of the signature should be on the same page as the rec9rd and should immediately follow each record entry. Either the original or a reproduced copy or mi-croform (duly authenticated)

may be maintained to meet the storage requirements of §20.401.

D. IMPLEMENTATION

The purpose of this section is to provide informa-tion to applicants and licensees regarding the NRC staff's plans for using this regulatory guide.Except in those cases in which the applicant or licensee proposes an acceptable alternative method, the staff will use the methods described herein in evaluating an applicant's or licensee's capability for and performance in complying with specified por-tions of the Commission's regulations after January 2, 1979.If an applicant or licensee wishes to use the method described in this regulatory guide on or before January 2, 1979, the pertinent portions of the applica-tion or the licensee's performance will be evaluated on the basis of this guide.8.21-8

11M -ý0 TABLE I ACCEPTABLE

FREQUENCIES

FOR SURVEYS Amounts (Curies) In Process at Any One Time Within Any Room Requiring Surveys Radionuclide Group H-3. C-14. F-18.1 K-42.0 Cu-64.° Tc-99m." In-113m" External Radiation Surveys (nuclides with asterisks only)*Air Sampling"*

Surface Contamination

1: Weekly If point source of ac-tivity could cxcccd 50 mradh at I meter Monthly If point source of ac-tivity could exceed 0.5 mrad/h at I meter Weekly Monthly Quarterly Weekly<10< I ý1oo<z 100<ID<10 Monthly Quarterly'0!1: Br-82. Cr-51.° Fc-55.1-123." Hg-1971 HiE: S-35. Au-198. Ca-47.1-132, Cc-141, Mixed Fis-sion products., Sr-85. La-140. Nb-95. Zn-65, Co-58." Fe-59.° Na-24., Co-57., Se-75.1 MN-99" IV: Hf-181. Pm-147. P-32.*Ra-140." Th-234. Kr-tS.lr-192." CI-36. Y-91. Ta-M82. Ca-45. Sr-X9. Cs-137.Co-60.1 Cc-144.° 1-126.Eu-154. 1-131.* 1-125." Tm-170. Na-22." Mn-54." Ag-Ii0m.*

iHg-203.°

Rn-222.' Sn- 1131 V: Tc-99.1-129, Ru-106 VI: Ra-223. Po-210. Th-227.Sr-90. Pb-210. Cm-242.U-233 VII: Sm-147. Nd-144. Ra-226." Cm-244, Ra-229. Pu-241 I So.< I<0.1.10 0.1 0." 01<0.1<0.01>! 0. 1<0.1 o.01 -0.001<0.01<0.001-.0.1 -0.01 0.1<0.01<1 ,0.001 10-1-:10-1<0.011<0.01< lo- -0.001 -.10_11 0.001* 0t o-, to-to0,<10- z to-- 10-8t '<0.001<10-" 710' >1'VIII: Am-233. Am-24l.* Np-237. Ac-227. Th-230. Nu-2412. Nu-2311, Pu-240. Pit-239. Th-22It. Cf-252'Nucides Aith asterisk%

are thoic mitre likely wrequire externnal radiation surkey%.*As~uming cointifloutiti

%ampling i% unneeev..ary (see Sectioin C. 1 3.7 10-,::. 1-T.10-'4<i0-'

TABLE 2 LIMITS FOR REMOVABLE

SURFACE CONTAMINATION

IN MANUFACTURING

PLANTS*Type of Radioactive Material**

Alpha Emitters Low-Risk High Lower Beta or X-Ray Beta or X-ray Toxicity Toxicity Emitters Emitters Type of Surface (.Ci/cm 2) (/CI/cm 2) (jACI/cm 2) (/Ci/cm 2)I. Unrestricted areas 10*1 10*1 10,3 10.4 2. Restricted areas 101, I0"3 10"3 10.2 3. Personal clothing I0"" 10"4 10"' 10"1 worn outside of restricted areas 4. Protective clothing worn 10.4 10*3 l0"3 103 only in restricted areas 5. Skin 0Ils 10.- 10"'- 10"3*As adapted from Table I of Reference

4. Averaging is acceptable over inanimate areas of up to 300 cml or. for floors, walls, and ceiling. 100 cm-. Averaging is also acceptable over 100 cm: for skin or. for the hands. over the whole area of the hand. nominally 300 cm'.-High toxicity alpha emitters include Am-243. Am-241. Np-237. Ac-227. Th-230. Pu-242. Pu-238. Pu-240. Pu-239. Th-228.and Cf-252. Lower toxicity alpha include those having permissible concentrations in air greater than that for Ra-226 (s) in t0 CFR Pan 20. Appendix B. Table I. Column I. Beta or x-ray emitter values are applicable for all beta or x.ray emitters other than those considered low risk. Low-risk nuclidcs include those whose beta energies arc <0.2 MeV maximum. whose gamma or x-ray emission is less than 0. 1 Rth at I meter per curie, and whose permissible concentration in air in 10 CFR Part 20. Appendix B. Table I is greater than 10-' pCilml.Note: Contamination limits for unrestricted areas in this table are considered to be compatible in level of safety with those for release of facilities and equipment for unrestricted use. as given in Regulatory Guide 1.86. 'Termination of Operating Licenses for Nucleur Reactors." and in "Guidelines for Decontamination of Facilities and Equipment Prior to Release for Unrestricted Use or Termination of Licenses for Byproduct.

Source. or Special Nuclear Material." which is available from the Division of Fuel Cycle and Material Safety. Office of Nuclear Material Safety and Safeguards.

U.S. Nuclear Regulatory Commission.

Washington.

D.C. 20555.8.21-10

REFERENCES*

I. National Commission on Radiological Protection (NCRP) Report No. 8. "Control and Removal of Radioactive Contamination in Laboratories." December 15, 1951.2. NCRP Report No. 9, "Recommendations for Waste Disposal of Phosphorus-32 and Iodine-131 for Medical Users." November 2. 1951.3. NCRP Report No. 10. "Radiological Monitoring Methods and Instruments," April 7. 1952.4. International Atomic Energy Agency (IAEA)Technical Report Series No. 120. "Monitoring of Radioactive Contamination on Surfaces." 1970.5. IAEA Safety Series No. 38. "'Radiation Protec-tion Procedures," 1973.6. IAEA Safety Series No. I, "Safe Handling of Radionuclides." 1973 Edition. Code of Practice Sponsored by the International Atomic Energy Agency (IAEA) and the World Health Organiza-tion (WHO). 1973.7. IAEA Technical Report Series No. 133. "*Hand-book on Calibration of Radiation Protection Monitoring Instruments." 1971.8. IAEA Safety Series No. 25. "Medical Supervi-sion of Radiation Workers," sponsored jointly by IAEA. WHO, and ILO. 1968.9. International Commission on Radiological Pro-tcction (ICRP) Publication

12. "General Princi-ples of Monitoring for Radiation Protection of Workers," Pergamon Press. 1969.10. AAPM Monograph No. 1. '-Biophysical Aspects of the Medical Use of Technetium-99m.'" J.G.Kereiakes and Karen R. Corey. Editors (avail-able from American Association of Physicists in Medicine, Dr. James G. Kereiakes.

E555 Medi-cal Sciences Building.

University of Cincinnati.

Cincinnati, Ohio 45267), 1976.II. International Commission on Radiation Units and Measurements (ICRU) Report No. 12. "Cer-tification of Standardized Radioactive Sources." September

15. 1968.IAEA rcports may be obtained from UNIPUR. Inc.. P.O. Box 433. New York. N.Y. 10016.ICRP reports may be ob;,incd from Pergamon Press. Maxi*ll House. Fairview Park. Elmsford.

Neu York 10523.ICRU reports may be obtained from the International Commission on Radiation Units and Measurements.

P.O. Box 30165. Wash-ingtn,, D.C, 20014.NCRP reports may be obtained from NCRP Publication.%.

P.O.Box 30175. Washington, D.C. 20014.8.21-11