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)

.... ..-:/-.IU.S. NUCLEAR REGULATORY

COMMISSION

May 1978REGULATORY

GUIDEOFFICE OF STANDARDS

DEVELOPMENT

REGULATORY

GUIDE 8.21HEALTH PHYSICS SURVEYS FOR BYPRODUCT

MATERIAL

ATNRC-LICENSED

PROCESSING

AND MANUFACTURING

PLANTS

A. INTRODUCTION

Paragraph

20.201(b)

of 10 CFR Part 20. "Stand-ards for Protection Against Radiation,"

requires thateach licensee make or cause to be made such surveysas may be necessary.for him to comply. with theregulations 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 othersources 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 inplants 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 AsIs Reasonably Achievab niciplcs, methods, andinstrumentation for c radiation.and con-*tamination survr er ev f6ped early in theatomic energy togra n ave been discussed inreports 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

POSITIONMin this guide are accept-ableýfiithe stuiff for estahlishing acceptable sur-vey pr grams,.In accordance with thie as hlw as is achievable (ALARA) philosophy.

-Man-iffacttrs licensed by the NRC should have, a healthp'h sics staff capable of developing and implementing

.survey programs as described below.I. Types of SurveysI. I General Description Surveys performed in compliance with §20.201 of10 CFR Part 20 should include those necessary toevaluate 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 thisguide to connote the personal inspeclion of various localions in afacility using radioactive materials.

with or without ,accompanying measurements, to determine the cfreetivenes',

ot' o islures hit pln-tect against radiation.

• USNRC REGULATORY

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

distlributionit tin utops s enqt" n.. '11 lseIt~i'lf trra=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.1Radiation protection programs should include thetypes of surveys discusscd below.1.2 Surveys or External Radiation ExposureLevels in Restricted AreasRadiation 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 quartetor 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 ofthese 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 shouldmonitor themselves if they are exposed to externalradiation levels that could exceed any of the limits ofparagraph

20.101(a).

These surveys by workersshould consist of periodic instrument surveys duringwork with radioactive materials.

Workers should beproperly 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 ofpersonnel dc.,imcttry data. e.g.. as a result of losingthe dosimeter or chemical or physical damage to thedosimeter, the best alternative means of estimating the exposure may be to use survey data in conjunc-tion with appropriate occupancy factors.

In suchcase, the estimate, including the survey data used.should be documented and retained indefinitely (seeparagraph

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

Survey results supple-ment personnel monitoring, when it is required, andtlhcy 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 AirThe radiation safety staff should perform mcas-I However.

the radiation safety program should include surveysor 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 isnot intended to indicate that such staff necessarily consists olmore ihan one person designated as responsible for radiation safety,The size and qualifications of the staff depend on the scope andkind of manufacturing activities involving radioactive materials.

urements of radioactive material concentrations inair, at frequencies specified in Section C.2 of thisguide, 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 ofthe air in the workers'

breathing zone. However,-when obtaining representative samples from thebreathing zone is not practicable, the samples shouldbe obtained frotm a location at which the radioactivity concentration in air is known to be greater than thatof the workers'

breathing zone. For example.

sam-pies taken outside the breathing zone are acceptable ifthe sampler head is located so that the concentration of radioactive material in air at the location of thesampler 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 mediaand by material collected on the filter. Filter mediaused for the collection of alpha emitters should retaincollected material on the filtcr surface.

Overestimates of the volume of air that has passed through the filtershould be avoided by means of accurate calibration ofthe flow rate and by preventing or correcting for theloss of flow due to the accumulation of material onthe filter.Breathing zone or general air sampling should becor.ducted while work is in progress unless the resultsof continuous sampling verify that the concentration of radioactive material in the breathing zone is notlikely to exceed 25 percent of the values given in 10CFR Part 20, Appendix B. Table I. Column i. Theuse of personal (lapel) samplers is acceptable for con-tinuous air sampling.

The air sampling frequency, ifnot continuous, and the times selected for samplingshould be based on the nature of the manufacturing process involved and the probability that airborneradioactive material will be present.

When assessing this probability is difficult, frequencies based on in-formation given in Section C.2 and Table I of thisguide 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 roomor area where radioactive material is handled, thelicensee should perform an analysis to determine whether an air monitor is necessary.

Each analysisI 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 alarmcapability, and an audible alarm system.8.21-2*1 should be kept available for inspection."

An airmonitor should be provided if the analysis indicates that it is likely that, before the air monitor alarm isactuated, accidental conditions could cause an intakeof radioactive material exceeding the intake thatwould result from inhaling such material for 4() hoursat the concentrations specified in 10 CFR Part 20.Appendix B, Table I. Column 1.1Workers should recognize that the principal func-tion of an air monitor is to alert personnel to takeimmediate action to protect themselves from expo-sure to the unexpected release of airborne radioactive material.

Inhalation exposures are in progress duringthe 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 timeperiod. In particular, the air inlet of the monitorshould be located near the potential source of air-borne radionuelides, preferably between the sourceand the workers.

The use of long tubing or pipingleading to the inlet should be avoided because of thehigh 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 alow 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 orificethat is intended to provide a constant flow rate shouldnot be used with an air monitor because it is moreimportant to maximize the volume of air drawnthrough the filter, thus reducing the time of exposurebefore the alarm by using a higher flow rate, than tomeasure the concentration accurately.

1.4 Surface Contamination SurveysRoutine 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 surfacecontamination may result in unnecessary external orinternal exposure of personnel to radiation.

Althoughexternal radiation levels from radioactive contamina- tion may at times be hazardous, the primary concernis to avoid internal exposure resulting from the intakeof 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 theanalysis 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 valuespecified in Appendix B to 10 CFR Part 20 by 4.8 x 10' mi.present on a surface that can be transferred to a smeartest 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 surveysappropriate 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. uniformmethods for collecting and analting smear sample:.should he used over extended periods to time in orderto evaluate trends. Counting equipment used toanalyze radioactive contamination on smear samplesshould he properly calibrated and rnaintaii.ad andshould be capable of detecting the radiation from thesmears. For example.

smears containing how-energy radiation emitters (e.g.. H-3. C-14. 1-125) should heanalyzed with liquid scintillation or internal propor-tional counters.

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

thin, end-window detector in order ioa. Ensure that gross contamination levels are notalready too high for counting in sensitive equipment.

b. Minimize the chance for inadvertent spread tolcontamination- by the smear survey or other activities to be performed in the meantime, andc. Determine which areas require greater atten-tion in smear testing.The instrument used should have a readout systemwith a short time constant and should be equippedwith earphones or an external speaker system.A standardized method for smear testing of arelatively uniform area should he used to aid in com-paring contamination at different times and places. Adry smear taken from an area of about 100 cnm- isacceptable to indicate levels of removable contamina- tion.A diagram of each routinely surveyed areashould be used for recording survey results.

This pro-cedurc will provide radiation safety personnel wilh amethod for identifying trends as well as satisfying regulatory requirements for survey records.

The sur-veyor will find it helpful to specify key locations tonthe survey diagram that are smear-tested at each sui-vcy and also to provide a space reminding therecorder to include:a. Contamination levels converted t) radioactiv- ity units in terms of equivalent alpha. beta, or gammaemission per unit area, in units specified in 10 CFRPart 20.b. The make and model number of instruments used in the survey and in counting the smear samples.08.21-3 c. The disintegration rate of each sample,d. The background count.e. All counting times, andf. The name and date of the person making theevaluation and recording the results.Provision should also be made on the diagram forrecording 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 beconducted by the radiation workers themselves;

theyneed not be recorded.

For example.

a contamination survey can be made by collecting a smear sample andholding it against a thin (less than 2 mg/cm-) end-window detector while the detector is in an areawhere radiation levels are less than about 0.05mrem/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 timesand noting the meter readings.

This method may beused for the majority of radionuclides processed inmanufacturing plants (excluding alpha and very low-energy beta emitters).

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

Each applicant may proposeand justify what removable surface contamination limits will be allowable before decontamination willbe performed in each work area. These limits shouldbe based on the need to avoid transfer of significant amounts of contamination to unrestricted areas and tomaintain 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 theNRC staff and may be used without justification bythe applicant.

1.4.2 Fixed Contamination For the purposes of this guide, "fixed contami-nation" is defined as radioactivity remaining on asurface after repeated decontamination attempts failto significantly reduce the contamination level. Sincemost detectors respond to both removable and fixedcontamination, 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 maypropose and justify what total contamination limitswill 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 NRCstaff and may be used without justification by the ap-plicant.1.5 Protective Clothing and Equipment Contami-nation SurveysIndividuals working in areas where a potential forskin 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 Part20 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 therestricted area. Since airborne radioactivity from con-taminated protective clothing is likely to be producedby dislodging any absorbed radioactive particles dur-ing removal, fixed station monitors should also beavailable in clothing change areas to survey clothingbefore it is removed.

In addition, suitable areasshould be provided for surveying protective clothingand equipment before storing them for further use orfor decontamination and laundering.

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

The applicant may propose andjustify protective clothing contamination limits con-sidered adequate for each restricted area; the limitsgiven on line 4 of Table 2 are acceptable to the NRCstaff 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 shouldinclude the names of persons surveyed, a description of prior work activities, the probable causes, stepstaken to reduce future incidence of contamination.

times and dates, and the surveyor's signature.

Thisinformation may be entered in a logbook.

Individtial worker surveys of themselves need not be recordedunless the limits on line 3 of Table 2 are exceeded.

However, the radiation safety staff should maintaindaily surveillance to ensure that the workers continuetheir own personal contamination surveys.

Results ofradiation safety surveillance should be recorded.

In restricted areas with little potential for surfacecontamination, personal clothing is often worn be-neath protective clothing.

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

.Ipracticable nor necessary for employees working withonly 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 thensurvey and supervise any necessary decontamination or clothing disposal.

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

Records should be maintained in the same manner asthose 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 arenormally provided.

In this case, personal clothingshould be stored outside the restricted area. Surveysof personal clothing are not necessary, provided thearea in which the clothing is stored is surveyed asdiscussed in Section C. I.4 of this guide and the sur-vey results are below the limits adopted ror in-plantunrestricted areas. Particular attention should be paidto surveying the body. hair. bottoms of the shoes orfeet. and the hands after removal of protective cloth-ing and to washing before donning personal clothing.

1.6 Personal SurveysIndividuals whose duties require work in restricted areas where radioactive contamination of body sur-faces is probable should also survey all exposed areasof the body after showering and before donning per-sonal clothing or leaving the restricted area. Workersshould be required to report the detection of contami-nation on the body to the Radiation Safety Office.Decontamination attempts, under the direction ofRadiation Safety Office personnel or a medical con-sultant, should be repeated until (I) such attemptscease to effect significant reductions or (2) such at-tempts threaten to damage the skin.' When decon-tamination attempts are terminated, there should beno further concern if the residual contamination doesnot exceed preslected levels since the contamination would no longer present a significant ingestion hazard. Such levels may be proposed and justified bythe applicant:

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

If residual contamination exceedsthe selected limits, the affected individual should bereleased but periodic surveys should be made untilthe limits are no longer exceeded.

The resulting doseshould 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 andwater or it) decontamination procedures previously agreed upon bythe medical consultant.

If such attempts do not reduce the con-lamination to acceptable levels. the aid of a physician should heobtained.

personnel dosimetry reco rd. Complete records shouldbe maintained (if each incident of this nature.Since manufacturing plants often process 1;.rgequantities 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 theRadioisotopes Licensing Branch.1.7 Surveys of Equipment Prior to Release to Un-restricted AreasSurface contamination:.

Ntrcys should be con-dueled for both removable and fixed contamination before potentially contamiatated equipment is releasedfrom restricted to unrestr:Ltcd areas. If contamination is detected, decontamination procedures should berepeated 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 areason line I of Table 2 are acceptable to the NRC staffand need not be justified by the applicant.

1.8 Drinking WVaierAlthough it is highly unlikely that significant internal exposures will result from ingesting drinkingwater near worl. areas (Ref. 4). any water fountains in these areas should be smear-tested regularly, andthe water should be sampled and analyzed at leastquarterly.

Also. surveillance should be included inthe radiation safety program to ensure that workersobserve rules to prevent ingestion tof radionuc;ides.

e.g.. rules pertaining to eating. drinking, or smokingin 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 PackagesPrepared for ShipmentExternal radiation surveys and smear tests of ex-ternal surfaces of packages received or packaged lforshipment should be carried out near the receiving orpackaging point to avoid inwarranted radiation expo-sures and inadvertent contamination of personnel orthe 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) andspecific license conditions.

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

Surveys should be made to determine when cartsrather than hand carrying should be used. Packagescontaining 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 hotcell.No packages should be released for shipment ortransfer to tither users unless contamination levels ofinternal sources or devices have been tested and cer-tified to meet the criteria of paragraph

35. 14(b)(5)

forGroup VI products or license conditions for otherproducts as provided in §35.14 or in the manufac-turer's license.

Also. no packages may be releasedfor shipment or transfer when external radiation orsurface contamination levels exceed limits set by theDepartment ot Transportation in Title 49 of the Codeof 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 toEmployees.

copies o0 licenses, and tither items areproperly posted. legible, and operative, as requiredby 10 CFR Parts l0 and 20 or license conditions.

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

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

Temporary signs. signal-.

or bar-riers logether with appropriate worker notification and instruction may be used in the interim whenitems as specified in 10 CI-R Parts 19 and 20 are notavailable, hut acceptable corrections should be pro-vided as soon as practicable.

1. II Leak Tests of SourcesLeak testing of sealed sources must be carried outin accordance with the terms and conditions of themanufacturer's materials license.

Also. as providedin 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 (exceptiridium-192 seeds encased in nylon ribbon) orb. More than 10 microcuries of an alpha emittermust be leak tested for contaminalion or leakage atinterv'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 towithin =20 percent at a minimum of two points neirthe lower 25 percent and upper 25 percent readings ofeach 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 isused for survey instrument calibration.

All decay cor-rections should be included in the radiation safetyrecords system. A posted graph for each source isconvenient, 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 forat least one point near the midrange of each scale inuse and a battery check are necessary at least as oftenas every 3 months in order to ensure the accuracy andoperability of portable radiation survey instruments.

In addition, long-half-life

onslancy check sourcesshould be used to check the continued accuracy of allinstruments each time they are used.1.13 Surveys of Protective Clothing Before andAfter 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 licensedto process and handle radioactively contaminated clothing.

Each garment returned from a licensed laundryshould be monitored before use. If contamination levels on the garment exceed those given on line 4 ofTable 2. the garment should not be used.1. 14 Ventilation SurveysRadiation safety personnel should conduct surveysmonthly (or more frequently)

to determine the facevelocity of air at the entrance of radiological-type fume hoods in use to protect workers against thehazards 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 facevelocity 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 fivedifferent 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-tubemanometers or the equivalent sho~uld be pr(vided to indicate thepressure drop across the filters.

thus affording an early indication of airflow loss at cnctioures.

'4I I8.21-6 In addition to these surveys.

each enclosure shouldbe equipped with a device that measures pressuredrop across the hood filter. Workers should be in-structed to maintain daily checks of these devices andto notify radiation safety personnel when the pressuredrop exceeds a preset level.A thermoanemometer or velometer should be usedat least semiannually to determine the number of airchanges per hour provided by the ventilation systemin each room in which work with uncncapsulated radioactive materials is conducted.

A minimum of sixchanges per hiur should be provided.

1. 15 Surveys in In-Plant Unrestricted AreasUnrestricted areas should be surveyed periodically to ensure that radiation and radioactive material areadequately confined in restricted areas, except incases where these materials must be transported be-tween areas. Such transportation should be surveyedor planned with the radiation safety staff.1. 15.1 Surface Contamination SurveysRemovable surface contamination surveys in un-restricted areas should be performed and recorded atfrequencies consistent with the potential for spread-ing contamination but not less frequently than quar-terly. With the exception of lunch rooms and snackbars, random smear testing of floors and furniture isadequate.

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

If such surveys reveal thatradioactive contamination is being transferred out ofrestricted areas, immediate corrective action shouldbe taken to eliminate such transfers, and decontami- nation efforts in the unrestricted areas should be re-peated until it is evident that subsequent effortswould 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 isascertained and corrected.

The applicant may proposecontamination 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 theapplicant.

1.15.2 Radiation SurveysRadiation surveys in unrestrictcd areas should beperformed and recorded at frequencies consistent with the types and quantities of materials in use butnot less frequently than quarterly.

These surveysshould be made in areas adjacent to restricted areasand 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 SurveysThe term "surveillance."

as used in this sec.tion. refers it) observations of radiological

,,orkingconditions in restricted areas made by the person ,.lhoperforms the routine radiation and contamination sur-veys. Such surveillance, one of the most important aspects of a radiation protection program.

allowshealth physics personnel to acquire detailed knol-edge of each operation in order t) (1) identify wavsof 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 indetail, to describe potential hazards and the precau-tions taken to minimize exposures.

and to discusshow 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 ofPersonnel The surveillance program inc'udes:

a. Regular inventory of radioactive materials andtheir locations.

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

These surveillance activities may be condu.tcd during the performance of other survey measurements or tests. The radiation safety staff should conductsurveillance inspections in a manufacturing plant atleast weekly. The surveillance should be perf'ormed at least annually by the Radiation Safety Officer inthe presence of a management representative such asthe plant manager to provide management with anawareness of the nature and importance of activities conducted for personnel protection and plant safety.2. Frequency of SurveysThe frequency of routine surveys depends on thenature. quantity, and use of radioactive material%,

aswell as the specific protective facilities, equipment.

and procedures that are designed to protect theworker from external and internal exposure.

Generally.

surveys should be performed beforeradioactive materials are used in a new facility inorder to establish a baseline of background radiation levels and radioactivity from natural sources, struc-tural components of the facility (including radon and8.21-7 thoron emanation rates and concentrations),

and anyalready existing operations with radiation sources innearby rooms or facilities.

These baseline surveysshould be performed under the various conditions ofcontainment, shielding design, and process heat loadsto be expected under manufacturing conditions.

Sur-veys of simulated process operations withnonradioactive reagents or smaller amounts ofradioactive material should also be performed whereappropriate 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 presentand conducting their job functions.

Surveys shouldalso be conducted after any significant changes in theconditions that existed at the time of the most recentsurvey, including changes in the quantities ofradioactive material handled or in protective equip-ment and procedures.

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

Surveysare also necessary for procedures in which sealedsources are handled outside shielded containers.

For operations involving materials in gas. liquid, orfinely divided forms, the survey program should bedesigned to monitor the continued adequacy of con-tainment and control of the materials involved.

The minimum acceptable frequencies of surveysfor manufacturing plants are given in Table I. TheNRC staff considers the frequencies established inTable I to meet the requirements of §20.101 of 10CFR.3. Records of SurveysReference should be made to §§20.401 and 30.51and 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 requiresthat licensees maintain records in the same units usedin Part 20. Thus, external exposure rates should berecorded in estimated maximum dose equivalent unitsto relevant parts of the body as specified in 10 CFRPart 20. Air concentration measurement results inunits of j.Ci/ml and surface contamination measure-ment results in units of dpm/l00 cm2 or .Ci/100 cm2(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)

requiresthat survey records be preserved for 2 years, exceptthat records of air monitoring and (in the absence ofpersonnel 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 thedate of the signature should be on the same page asthe rec9rd and should immediately follow each recordentry. Either the original or a reproduced copy or mi-croform (duly authenticated)

may be maintained tomeet the storage requirements of §20.401.

D. IMPLEMENTATION

The purpose of this section is to provide informa-tion to applicants and licensees regarding the NRCstaff's plans for using this regulatory guide.Except in those cases in which the applicant orlicensee proposes an acceptable alternative method,the staff will use the methods described herein inevaluating an applicant's or licensee's capability forand performance in complying with specified por-tions of the Commission's regulations after January2, 1979.If an applicant or licensee wishes to use the methoddescribed in this regulatory guide on or beforeJanuary 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 -ý0TABLE IACCEPTABLE

FREQUENCIES

FOR SURVEYSAmounts (Curies)

In Process at Any One Time Within Any Room Requiring SurveysRadionuclide GroupH-3. C-14. F-18.1 K-42.0Cu-64.° Tc-99m."

In-113m"External Radiation Surveys(nuclides with asterisks only)*Air Sampling"*

Surface Contamination

1:WeeklyIf point source of ac-tivity could cxcccd 50mradh at I meterMonthlyIf point source of ac-tivity could exceed0.5 mrad/h at I meterWeekly Monthly Quarterly Weekly<10< I ý1oo<z 100<ID<10Monthly Quarterly

'0!1: Br-82. Cr-51.° Fc-55.1-123." Hg-1971HiE: 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- 1131V: Tc-99.1-129, Ru-106VI: Ra-223. Po-210. Th-227.Sr-90. Pb-210. Cm-242.U-233VII: Sm-147. Nd-144. Ra-226."Cm-244, Ra-229. Pu-241I So.< I<0.1.100.10." 01<0.1<0.01>! 0. 1<0.1o.01 -0.001<0.01<0.001-.0.1 -0.010.1<0.01<1,0.00110-1-:10-1<0.011<0.01< lo- -0.001 -.10_110.001* 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 2LIMITS FOR REMOVABLE

SURFACE CONTAMINATION

IN MANUFACTURING

PLANTS*Type of Radioactive Material**

Alpha Emitters Low-RiskHigh Lower Beta or X-Ray Beta or X-rayToxicity Toxicity Emitters EmittersType of Surface (.Ci/cm2) (/CI/cm2) (jACI/cm2) (/Ci/cm2)I. Unrestricted areas 10*1 10*1 10,3 10.42. Restricted areas 101, I0"3 10"3 10.23. Personal clothing I0"" 10"4 10"' 10"1worn outsideof restricted areas4. Protective clothing worn 10.4 10*3 l0"3 103only in restricted areas5. 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, andceiling.

100 cm-. Averaging is also acceptable over 100 cm: for skin or. for the hands. over the whole area of the han

d. 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 t0CFR Pan 20. Appendix B. Table I. Column I. Beta or x-ray emitter values are applicable for all beta or x.ray emitters other thanthose considered low risk. Low-risk nuclidcs include those whose beta energies arc <0.2 MeV maximum.

whose gamma or x-rayemission 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 Iis 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 releaseof facilities and equipment for unrestricted use. as given in Regulatory Guide 1.86. 'Termination of Operating Licenses for NucleurReactors."

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 MaterialSafety. 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 Removalof Radioactive Contamination in Laboratories."

December

15, 1951.2. NCRP Report No. 9, "Recommendations forWaste 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 ofRadionuclides."

1973 Edition.

Code of PracticeSponsored by the International Atomic EnergyAgency (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 jointlyby IAEA. WHO, and ILO. 1968.9. International Commission on Radiological Pro-tcction (ICRP) Publication

12. "General Princi-ples of Monitoring for Radiation Protection ofWorkers,"

Pergamon Press. 1969.10. AAPM Monograph No. 1. '-Biophysical Aspectsof the Medical Use of Technetium-99m.'"

J.G.Kereiakes and Karen R. Corey. Editors (avail-able from American Association of Physicists inMedicine, Dr. James G. Kereiakes.

E555 Medi-cal Sciences Building.

University of Cincinnati.

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

September

15. 1968.IAEA rcports may be obtained from UNIPUR. Inc.. P.O. Box433. New York. N.Y. 10016.ICRP reports may be ob;,incd from Pergamon Press. Maxi*llHouse. 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