ML20204C881

Reg Guide 8.24,Health Physics Surveys During Enriched U-235 Processing & Fuel Fabrication. Delineates NRC-accepted Survey Methods,Procedures & Criteria

ML20204C881
Person / Time
Issue date:	11/30/1978
From:	NRC OFFICE OF STANDARDS DEVELOPMENT
To:
References
REGGD-08.024, REGGD-8.024, NUDOCS 7812050275
Download: ML20204C881 (9)

Text

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i U.S. NUCLEAR REGULATORY COMMISSION Novsmbsr 1978 pa "%s*

@()s REGULATORY GUIDE

• .e** OFFICE OF STANDARDS DEVELOPMENT

! REGULATORY GUIDE 8.24 HEALTH PHYSICS SURVEYS DURING ENRICHED URANIUM-235 PROCESSING AND FUEL FABRICATION f atomic energy program and have been discussed in A. INTRODUCTION reports of the National Council on Radiation Protec-Paragraph 20.20l(b) of 10 CFR Part 20, " Stand- tion and Measurements (NCRP) (Refs.1-3, the-ards for Protection Against Radiation," requires that International Atomic Energy Agency GAEA) (Refs.

cach licensee make or cause to be made such surveys 4-7), .and the International C8iinnission on as may be necessary for him to comply with the Radiological Protection (ICRP) (Ref. 8).'More recent regulations in that part. As used in Part 20, the term reports (Refs. 9-10) conta$ad(litional iriformation

" survey"is defined as an evaluation of the radiation for use in establishing radiahonTuryAp programs and hazm16 incident to the production, use, release, selecting methods anfequipmenP for their im-disposal, of presence of radioactive materials or other plementation. Surve/siare#ecessary supplements to sources of radiation under a specific set of condi- personnel monit9 ring,lnTwhich devices worn by the tions. This guide specifies the types and frequencies workers measure %mdividsali e^xternal radiation expo-j of surveys that are acceptable to the NRC staff for the sures, and 16 various" forms of bioassay to determine protection of workers in plants licensed by the NRC intake of r$dindYe m5terial by the workers.

for processing enriched uranium and for the fabrica- 4% %V S me enrichep uranium processing and fuel fabri-tion of uranium fuel.

cation plants. conduct operations with Class D (trans-This guide does not relate to the processing of 'poitablehwith rapid clearance from the lung) uranium uranium-233. Further, this guide does not specifw ically deal with a number of aspects of an acceptable' ncompdtmds for which considerations o occupational health physics program that are close19 hhemical hazards such as HF that are not addressed in related to surveys:(1) the number and qualification ofy' this guide.) Other plants conduct operations with the health physics staff; (2) instrumentatiogin"clud Class W or Y (nontransportable, with 50- or 500-day ing types, numbers of instruments, limitations of uh;i biological half-life in the lung) compounds only. In accuracy, and calibration; (3) personnel dhsimetry; the latter case, considerations of dose equivalent to and (4) bioassay. Guidance on bioassay for uramum the lung are limiting. Such differences in plant appears in Regulatory Guide 811., " Applications of operation were considered in the development of this Bioassay for Uranium." fM guide.

gH.4 B. DISCUSSION C. REGULATORY POSITION n v v Surveys are considered to,he part of a comprehen- Methods, procedures, and criteria in this guide are sive protection 0 program.cstablished by the licensee acceptable to the NRC staff and may be incorporated into appropriate sections of a license app!ication.

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according to'the philoshphy and principles of Regu-F latory Guide 8.'10,," Operating Philosophy for Main- This guide is intended to assist applicants in prepar-taining Occupational Radiation Exposures As Low As ing license applications and to assist licensees in g establishing acceptable survey programs in accord-Is Reasonably Achievable." Principles, methods, and

- instrumentation for carrying out radiation and con- ance with the "as low as is reasonably achievable" tamination surveys were developed early in the (ALARA) philosophy.

comments should be sent to the secretary of the Commission, U.S. Nuclear USNRC REGULATORY GUIDES Regulatory Guidee are issued to describe and make available to the public orvice ra Staff eval The guides are issued in the followmg ten broad divisions:

Cm e ulat to t t es b Iubst tut a for regu$t s."and c 1 Power Ranctors 6. Products a sca Reg la ory Ou des e e 7.Transportaten phance with them is not requirerl. Methods and solutions different from those 2. Research and T est Reactors

3. Fuets and Matenals Facilities 8. occupatonal Health set out In the guides will be ecoeptable if they provide a base for the fendsngs rust end F mancial Review requate to the insuance ne contmuence of a permit or hcense by he Envuonme i S Comments and si ,pentons for improvements in these Guides are encouraged Requests for single copies of issued guides (whch may be reproducedl or for et all times, arid puedes will be revised. es appropnote, to acenmmodate com- placement on en automatm distributon list for single copies of future guides monts and to reflect new informaton or exponence. However, comments on 6n specife divissors should be made in writing to the U.S. Nuclear Regulatory this guide, if received withm about two months atte 6ts issuance, will be Commissson, Washmgton, D.C. 20565, Attenten: Desctor, Dnnsen of particulerty usefulin evaluatin0 the need for en earty revmon. Technicalinformaton and Documerit Control.

781205 oa f __

1. TYPES OF SURVEYS thorium and protactinium daughters of uranium be-come separated as " bottoms," scale, or residue. The 1.1 General Description radiation levels near such sources should be sur-Section 20.201 of 10 CFR Part 20 specifies that veyed. Although most of the radiation levels in surveys be performed to demonstrate compliance operating areas are low, a reasonable effort should be with the other radiation safety requirements of that made to minimize individual and collective (manrem) part. Certain of these surveys are necessary to doses.

evaluate external exposure to personnel and concen- Preoperational, routine, and special radiation sur-trations of airborne uranium in the facility and in veys of the plant areas should be performed by the effluents from the facility. Monitoring of effluents is

, health physics staff as described in Regulatory Posi-beyond the scope of this guide. Applicable guides of tion C.2. Results of these surveys should be recorded Divismns 4 and 10 should be consulted for such as described in Regulatory Position C.3.

guidance.

'here operating personnel are subject to receiving Occupational radiation protection programs at en- m re than 25% of the dose limits, surveys are not riched uranium processing and fuel fabrication plants normally acceptable for compliance with the person.

should include the types of surveys discussed below. nel m n toring requirements of n 20.202 of 10 CFR Acceptabic survey frequencies are discussed in Reg- Part 20. However, in the absence of personnel ulatory Position C.2. dosimetry data, due, for example, to loss of or 1.2 Surveys of External Radiation Dose Rates chemical or physical damage to the dosimeter, an alternative means of estimating the exposure is to use NRC licensees are required by 6 20.202 of 10 CFR survey data in conjunction with appropriate occu-Part 20 to supply appropriate personnel monitoring pancy factors. In such e case, the estimate, including equipment to each individual who enters a restricted , the survey data used, must be documented and re-area under such circumstances that he is likely.to ,

tained indefinitely along with personnel monitoring receive a dose in any calendar quarter m excess of records pursuant to paragraph 20.401(c)(2)(ii). Survey 25% of values specified in paragraph 20.101(a) and results shculd be reviewed promptly by the health to require the individual to use the e;quipment. Ilealth physics staff in conjunction with personnel monitor-physics personnel should conduct imtial surveys t ng records (1) to identify potentially hazardous situ-identify all areas and operaGons where personnel ations and unfavorable trends and (2) to ensure that monitoring may be required and periodic surveys to all personnel are adequately monitored and that expo-detect any changes. The survey instruments used sures are maintained as low as is reasonably achieva-should be operable and capable of measuring, at or ble. Surveys for alpha radiation in enriched uranium below the required level, the types of radiation that processing and fuel fabrication areas are conducted will be encountered. Note that if workers will occupy primarily to assess the extent of contamination of the area essentially full time (520 hours0.00602 days <br />0.144 hours <br />8.597884e-4 weeks <br />1.9786e-4 months <br /> per quarter), personnel, equipment, and premises and to detect the periodic surveys should be made for beta-gamma loss of confinement. Such surveys are discussed in radiation at levels as low as 0.24 mrem /hr. Such snore detail in following sections.

levels may exist in a large fraction of the area of an enriched uranium processing or fuel fabrication plant 1.3 Measurements of Uranium Concentrations unless considerable care is taken to minimize expo- in Air sures. Beta-gamma radiation k.cls of 1 to 2 mrem /br it is essential to establish a comprehensive program usually exist at a distance of one foot or more from for assessing concentrations of uranium in air, st the surfaces of UO pellet trays or boats and fuel rods frequencies specified in Regulatory Position C.2 or bundles uad in areas where fuel bundles are stored. below, for each area where operations could expose Radiation levels of 5 to 10 mrem /hr may be found at workers to the intake of quantities of uranium ex-

'he surfaces of fuel rods and bundles, and levels of ceeding those specified in i 20.103. Special require-50 to 100 mrem /hr may be found near the surface of ments for such assessments may also be made a pellet trays und boats. Care should be taken to survey condition of the NRC license. Air samples should be and assess doses to hands and lenses of eyes received collected in such a way that the concentrations of by workers handling process materials (with gloves uranium are representative of the air in which work-or short tools). Much higher levels of gamma radia- ers are exposed.

tion may exist at such points as multiply used UFe .

Air sampling may be accomplished using fixed-cylinders or where operations involving melting or location samplers for hasic evaluation of the exposure reduction to uranium metal are conducted and the of workers, personal (lapel) samplers for supportive measurements and special studies, and air monitors i However, the radiation safety progam should include surve> s or far early warning of unexpected releases, records that indicate control of ti.e quantities of radioactive material retened in air and water to unrestncied areas as required WW. radiometric measurements of the quantity of by 10 CI R Pan 2n uranium d' posited on or in an air sample filter are 8.24-2 l t

being performed, appropriate corrections should be protective eqtaipment. An air monitor may be used to included for geometry and alpha (or beta) absorption provide a warning signal that the concentration of

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by the filter mMia and by material collected on the airborne uranium has become unexpectedly high. An filter. Filter media used should retain collected air monitor shouid be considered if conditions make k material on the fiher surface, and correction should it likely that an intake of uranium exceeding the be made for filter efficiency considering the particle limits in 5 20.103 may occur.

sizes and flow rates involved. Overestimates of the The principal function of the air monitor is to a!ert volume of air that has passed through the filter should personnel to take immediate action to protect them-be avoided by accurate calibration of the flow rate selves from unexpected airborne uranium. Inhalation

[ and by prevention of or correction for loss on flow exposures are in progress during the time between the rate due to the accumulation of material on the filter.

release of the uranium and the sounding of the alarm.

A means for measuring flow rate at air sampling Tb every reasonable effort should be taken to heads should be available. reduce this time period. In particular, the air inlet of Any air samples that are suspected of reflecting the monitor should be located near the potential releases and high concentrations, such as samples source of airborne uranium, preferably between the taken during glove-box glove changes, should be source and the woikers. The use of excessively long counted at once to identify any samples with quan- tubing or piping leading to the inlet should be tities of uranium greater than expected for the avoided because of the high probability of alarm 1 sampling location and volume. Procedures used delay due to uranium deposition on the interior walls should ensure prompt correction of the faulty control of the tube or pipe. The intake by personnel should or operation that led to the release and high sample. be reduced by the choice of setpoint. However, the Air samples should be counted again for record setpoint should not cause false alarms that weaken purposes after a routine period of time (24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> is the workers' confidence in the air monitor. The frequently used) for decay of the " background" intake by personnel may also be reduced by providing radon and thoron. The samples should be counted for a high flow rate of air through the filter. It is a sufficiently long period of time or until a suffi- important to maximize this flow rate, thus reducing ciently large number of counts has been observed to the time of exposure before the alarm.

establish the sample counting rate error within 1,4 Surface Contamination Surveys For contamination control inside the restricted area Fihm fmm personal (lapel) samplers should be ""I ' " " ' " # """" *'*""'""

counted and the data related to the uranium intake of ."

the wearer by application of factors for sampling taind mapm is handled and uncontrolled areas l where uramum is in the form of sealed sources or is f time, breathing rate, wearing time, and total working n t handled at all. Routine monitoring for uranium time. Filters from general air samplers should be ena a mn at couM k pmsent on swfaces d changed each working shift or more often in the event I1""'"' *"ll** E l""I #9" E * *"I' ' I"I"II"'* I" ' "~

of rapid buildup of material on the filter media, trolled areas ,is a necessary part of the survey which reduces the air flow. Consideration may be * " " " " ' # "I*' "#'"## ' "'"**""U "

E*E'""'

given to running samplers over weekends when no ""Y """ * """"""*"'I**Iemal m temal expo-work is in progress or to changing part of the sum of pers nnel to radiat.mn. Although surface samplers each day of a weekend. contamination contributes to the external radiation Paragraph 20.203(d) of 10 CFR Part 20 defines dose of workers, the primary concern is to avoid

" airborne radioactivity area" and prescribes posting internal deposition resulting from the intake of loose requirements. In setting forth the standards for limit- uranium by inhalation, ingestion, or penetration of ing intake of uranium, Section 20.103 requires licen- the skin.

sees to use process and other engineering controls to For the purposes of this guide, removable contami-the extent practicable to limit concentrations of nation is that uranium contamination present on a radioactive material in air to levels below thos surface that can be transferred to a dry smear test whien delimit an airborne radioactivity area. That paper by rubbing with moderate pressure. Methods section also provides for the use of other precaution- and instruments used in surveys of removable surface ary procedures such as mereased surveillance, lim-contamination should be capable of detecting the station of working times, or provision of respiratory alpha radiations from uranium at and below the levels protective equipment to maintain mtake of radioac-

, specified in Table 2. For example, smear counting tive material as low as is reasonably achievable.

Ilealth physics surseys of air concentration are es-sential in evaluating the changes obtained under 2 The term " air monitor" as used here refers to a device providing process and engineering controls, in conducting in. ' E' ' ' " " " * " ' ' ' ' . " " " " ' " * * " ' * " * " " ' " ' '

creased surveillance and limitinE workinE times, and conunuous recorder,"a meter mth preset alarm capability, and 'on in kupport of a program for the use of respiratory audible alarm system.

8.24-3

may be performed with proportional counters, alpha in writing the director of the appropriate Nuclear scintillation counters, or thin-window Geiger-Mueller Regulatory Commission Inspection and Enforcement (GM) subes. Regional Office listed in Appendix D to 10 CFR Part 20 at least 30 days before the date that respiratory Uniform methods for collecting and analyzing protective equipment is first used under the provi-smear st.mples should be employed. These stand- sions of paragraph 20.103(b)(2).

ardized methods should be employed over extended periods of time to aid in cross-comparison of con- Individuals working in areas where a potential for tamination at different times and places and in order skin or clothing contamination exists should wear to evaluate trends. A dry smear taken from an area of suitable protective clothing. Because it is likely that about 100 cm2 is acceptable to indicate levels of the radioactive material on contaminated protective removable contamination. A diagram of each clothing will again become airborne while the cloth-routinely surveyed area should be used for recording ing is being removed, monitors should be available in survey results. This procedure will provide radiation clothing change areas for workers to survey their safety personnel with a record that will assist in the clothing before removal and their bodies (particularly identification of trends. The surveyor will find it their heads, hands, and other exposed portions) after helpful to identify on the survey diagram the loca- removal of the protective clothing and before leaving tions that are smear-tested, the controlled area. Potentially contaminated clothing

.hould not he sent to a laundry that is not specifically Quantitative measuring instruments used to authorized to process clothing contaminated with monitor the adequacy of conf,mement and contamma- uranium unless the clothing has been surveyed and tion control, such as those used for measuring air found to have less than 200 disintegrations per samples, (md measurements to evaluate uranium minute per 100 cm2 of uranium contamination.

contaminatmn of personnel (bioassays), work areas (smear tests), and equipment should be calibrated and Individual workers' surveys of themselves need checked prior to use each day. The accuracy of the not be recorded unless the values in Table 2 are calibration source should be, as a minimum, 5% of exceeded. Ilowever, the health physics staff should the stated value and traceable to a pri nary standard maintain daily surveillance to ensure that the workers such as that maintained by the National Bureau of continue their own personal contamination surveys.

Standards. Observations during radiation safety surveillance should be recorded.

The regulatmns m 10 CFR Part 20 do not specify limits for surface contamination. Each applicant may Any personal clothing worn beneath protective propose and justify wurface contamination limits clothing should be surveyed before leaving the con-allowable before decontarnination is required in each trolled area. In the event that personal clothing work area. These limits should be based on the need contamination levels exceed preselected limits, to avoid transfer of contamination to uncontrolled workers should be instructed to report the situation to areas and to maintain exposures as low as is rea- the health physics office. A member of the health sonably achievable. The contamination limits for physics staff should then survey and supervise any controlled areas presented in Table 2 are acceptable necessary decontamination or clothing disposal. The to the NRC staff and need not be justified by the appheant may propose and justify personal clothing applicant. contamination limits; the level 200 disintegrations per minute per 100 cm3 is acceptable to the NRC staff 1,5 Protective Equipment and Clothing and need not be justified by the applicant. Records Contamination Surveys should be maintained in the manner described above for instances of protective clothing contamination.

When it is impracticable to apply process or other engineering controls to limit concentrations of For individuals whose work is conducted in con-uranium in air below those defined in paragraph trolled areas with a potential for high surface con-20.203(d)(1)(ii), other precautionary procedures such tamination levels, complete clothing changes are as increased surveillance, limitation of working normally provided. In this case, personal clothing times, or provision of respiratory protective equip- should be sorted outside the comolled area.

ment must be used to maintain intake of uranium by Surveys of personal clothing are not necessary in this any individual within the limits. When respiratory case if the area in which the clothing is stored is protective equipment is used to limit the inhalation of surveyed in accordance with Regulatory Position C.l.4 airborne uranium pursuant to paragraph 20.103(b)(2), of this guide and if survey results are below the limits the licensee may make allowance for such use in adopted for in-plant uncontrolled areas. After re-estimating exposures of individuals to uranium pro- moval of protective clothing and washing and before vided such equipment is used as stipulated in Regu- donning personal clothing and leaving the change latory Guide 8.15, " Acceptable Programs for Res- areas, particular attention should be paid to surveying piratory Protection." Licensees are required to notify the hair, bottoms of the shoes or feet, and the hands.

8.24 4

l 1.6 Personal Sur;veys limited to use inside the controlled area. The appli-

. cant may propose and justify total and removable Individuals whose dun.es involve work in con- contamination levels higher than those specified in trolled areas where uranium contamination of body the license for uncontrolled use. Such proposals

! surfaces is probable should survey all exposed areas should ensure that reasonable efforts will be made to I

of the body after washing and before donning per- eliminate the residual contamination.

sonal clothing and leaving the controlled area. Skin contamination levels may be proposed and justified 1.8 Surveys of Packages Received and Packages by the applicant. Workers should be required to Prepared for Shipment report to the health physics office if there is contami- External radiation surveys and smear tests of nation on the body that exceeds the preselected levels external surfaces of packages should be carried out fo!!owing attempts to both at the soap and water mg. wash, remove the Decontammation ecmtamination attempts bypackaging point before being sent to the shipping point and at the receiving point to avoid under the direction of the radiation safety staff or the unwarranted radiation exposure and inadvertent con-licensee s medical consultant should be repeated until tamination of personnel or the facility. Surveys and (1) such attempts cease to effect significant reduc- labeling must comply with regulatory requirements in tions or (2) such attempts threaten to damage the ss 20.203 and 20.205 of 10 CFR Part 20 and any sk,m . If the residual contammatmn does not exceed specific license conditions. Packages transported preselected levels when the decontammation attempts within the plant should also be surveyed and labeled.

are termmated, there should be no further concern When practicable, materials should be transferred by because the contammation would not then present a carts, conveyers, or other mechanical equipment significant mgestion or inhalatmn hazard. If residual rather than by hand-carrying. Packages (particularly contamination exceeds the selected limits, the af- . ..

pads or other containers contaming powder or other fected individual should be released, but periodic finely divided material) should not be opened until surveys should be made until the limits are no longer the packages have been placed in an appropriately exceeded. Complete records should be maintained of exhausted facility such as a hood or glove box.

each incident of this nature. Packages should not be released for shipment or Because of the potential for intake of uranium in transfer unless external radiation and contamination various chemical and physical forms, screening by levels are within the limits of the Department of means of nasal swabs and bioassay by means of Transportation regulations, urinalysis, fecal analysis, and in vivo counting should be performed if, on the bas,s i of air samph,ng M b e PW Mh Sim AA Signals, Controls, and Notices to Employees data, accident, equipment failure, etc., there is reason to believe that an individual might have taken The health physics staff should survey to ensure uranium into his or her body. Minimum acceptable that signs, labels, signals, other access controls, re-criteria, including numerical guidance on the initia- quired notices to employees, copies of licenses, and tion, selection, frequency, and interpretation of re- other items are properly posted, legible, and opera-suits for such programs, are provided in Regulatory tive as required by 10 CFR Parts 19 and 20 or spe-Guide 8.11, " Application of Bioassay for Uranium." cific license conditions. Criticality and air monitor alarms should be tested monthly unless the licensee 1,7 Surveys of Equipment, Premises, or Scrap provides justificanon for testing at less frequent Prior to Release for Uncontrolled Use mtervals. Any failure of such devices to perform as Surface contamination surveys should be con- intended should be promptly corrected.

ducted for both removable and total contamination 1.10 Leak Tests of S,ources prior to the release of potentially contaminated premises, equipment, or scrap from controlled to Leak-testing of sources such as those used in J

uncontrolled areas and use. If contamination is de- instrument calibration and quality control procedures

) tected or is known to have been covered, reasonable must be carried out in accordance with the terms and efforts should be made to climinate the contamina- conditions of the applicable specific license.

tion, i.e., decontamination procedures should be 1.11 Calibration of Radiation Safety repeated until additional efforts do not significantly Instruments reduce contamination levels. If the value of the items involved does not justify th. level of effort, the Portable survey instruments should be placed on a items should be disposed of as radioactive waste or routine maintenance and calibration program that will ensure that properly calibrated and operable survey

' Decontamination attempts without a medical consultant present instruments are available at all times for use by the should be restricted to approved decontamination procedures health physics staff.

greed upon by the hcensee and the licensee's medical consultant.

If such attempts do not reduce the contanunation to acceptable An adequate calibration of survey instruments levels, the aid of a physician should be obtained. cannot be performed solely with built-in check 8.24-5

sources. Electronic calibrations that do not involve a 1.13 Surveys ofIn Plant Uncontrolled Areas source of radiation also will not determine the proper Uncontrolled areas inside the plant should be functioning and response of all components of an nstmnm surveyed periodically to ensure that uranium is adequately confined in the controlled areas. Proce-Daily or other frequent checks of survey instru- dures should be established for the movement ments should be supplemented every six months with through corridors or other uncontrolled areas of the a two-point calibration on each scale of each instru- plant of uranium in any form that is capable of ment with the two points separated by at least 50 contaminating surfaces or of dispersal in air. Accept-percent of the scale. Survey instruments should also able survey frequencies are discussed in Regulatory be calibrated following repair. A survey instrument Position C.2; results should be recorded as described may be considered properly calibrated when the in Regulatory Position C.3. With the exception of instrument readings are within 10 percent of the lunch rooms, cafeterias, snack bars, and vending calculated or known values for each point checked. machine areas, random smear testing of floors alone Readings within 20 percent are considered accept- is adequate for most uncontrolled areas. In lunch able if a calibration chart or graph is prepared and rooms, cafeterias, snack bars, and vending machine attached to the instrument, areas, furniture and vending equipment as well as floors should be surveyed. If such surveys reveal that 1.12 Ventilation Surveys contamination has been transferred out of the con-trolled areas, immediate corrective action should be Health physics personnel should conduct surveys taken to eliminate such transfers and to decontami-monthly to determine that the velocity of air flow at nate the uncontrolled areas. Also, the uncontrolled the entrance of all hoods or other exhausted enclo- areas should be surveyed more frequently (e.g., daily sures and close-capture points is adequate to preclude or weekly) after contamination has been found until a escape of airborne uranium (considering density and trend of negative results is again established. The particle size of the materials present) and to minimize applicant may propose and justify permissible con-the potential for intake by workers. Such meas- tamination levels for in-plant uncontrolled areas. The urements should be made using a properly calibrated limits given in Table 2 are acceptable to the NRC thermoanemometer or velometer to determine staff and need not be justified by the applicant.

whether or not the air flow has been reduced to unacceptable levels by filter loading, malfunction of 1.14 Surveillance exhaust fans, etc. The average face velocity for a The term " surveillance" as used in this guide, hood used for specia( nuclear material with the sash refeis to observations of working conditions in and m the operating posittor W an opening in a special

, around the plant made by the health physics staff who enclosure should te 15J ft/ min (45 m/mm, ) as deter- perform the routine radiation and contamination sur-mmed from at least five different measurement

, veys. Such surveillance is considered by the NRC points. In addition to these surveys, each enclosure staff to be one of the most important aspects of a should be equipped w,th i manometers or other mdi- protection program. There should be a preconceived cators of the pressure drop across filters to pre. vide surveillance plan through which health physics per-early mdication of a reduction m air flow; the sonnel acquire and maintain detailed knowledge of readings of such devices .,hould be checked during each operation as necessary to permit (1) the identifi-each shift or more frequently for operations where cation of ways to prevent or minimize occupational high loading rates may occur. Corrective action exposures, (2) the selection of appropriate times for should be taken as soon as possible when the air flow making health physics measurements, and (3) is found to be deficient. Work should be terminated if adequate preparation for action to be taken in the the average face velocity falls below 100 ft/ min (30 event of breakdown of process equipment or other

• I* *) - emergency conditions. Health physics personnel who Surveys should be made of the negative pressure are responsible for performing surveys should be maintained inside glove boxes or other closed sys. sufficiently familiar with each activity to recognize tems. Additional surveys for airborne uranium, con. potential hazards so that precautions can be taken to

. tamination of personnel and equipment etc., should minimize exposures. Knowledge of procedures l be made during and after glove changes and any other within each activity is essential to the selection of operations during which the integrity of the system appropriate times for performing health physics may be lost. In addition to these surveys, each measurements.

enclosure should be equipped with a device that indicates the flow rate, pressure drop, or negative 2. FREQUENCY OF SURVEYS pressure in the enclosure. Workers should be in- The frequency of routine surveys depends on the structed to check on these devices and to notify the nature of the work being conducted, the quantities of health physics staff promptly upon indication of flow material being processed, and the specific protective rates below preset levels. facilities, equipment, and procedures used to protect 8.24-6

I the workers from external radiation and the intake of bioassay data should be specifically referenced or uranium. For example, the nature and frequency of documented in the exposed individual's record. If surveys appropriate for a plant in which all or a large specific information on the physical and biochemical

( portion of the work is conducted entirely within properties of the uranium compounds involved and closed systems are quite different from those con- their behavior in an individual is known, such ducted in plants having only hoods, exhausted enclo- information may be used and documented in the sures, or close-capture exhaust systems. exposed individual's record Generally, surveys should be performed prior to Records retention requirements are given in the the operation of the plant in order to establish a regulations cited above. Paragraph 20.410(c)(2) re-baselirse of background radiation levels and radioac- quires that survey records be preserved for two years, tivity from natural sources. These baseline surveys except that (1) records of air monitoring, bioassay by should be performed under various conditions to be urinalysis, fecal analysis, whole body or in vivo

, expected during routine plant operation. Surveys counting, etc., used to determine the intake of an should be ceaducted during test operation of any new individual in compliance with 9 20.103, (2) in the l absence of personnel monitoring data, records of 5 process or protective equipment, during significant changes in input materials or work load, and during surveys to determine external radiation dose, and (3) routine plant operations with all potentially involved results of surveys used to evaluate the release of h persons present and carrying out their functions. radioactive effluents to the environment (not treated Routine and repetitive surveys are necessary to in this regulatory guide) are to be maintained until the control the location of material within process NRC authorizes their disposition. Note that addi-equipment and handling systems and to ensure the tional information such as occupancy time may be continued integrity of protective equipment and the essential to the estimation of dose from survey data adequacy of procedures. The survey program should or the estimation of intake from data on air concen-be capable of monitoring the continuing adequacy of trations.

containment and control of the materials involved in Records may be maintamed .in logbooks or on the entire plant operation. Although the frequencies ,

special forms if they are clear, legible, understanda-of routine surveys depend on many factors and should ble, authenticated by authon, zed personnel, and con-be designed for the specific operations and facilities tain all of the mformation required. The signature of involved, minimum frequencies acceptable to the the person making the record and the data should be NRC staff as meeting the requirements of $ 20.201 of n the same page i ,mmediately following each record 10 CFR Part 20 are given in Table 1. entry. Either the or,g,nal ii or a reproduced copy or

) 3. RECORDS OF SURVEYS microform (duly authenticated) may be maintained to meet the storage requirements of f 20.401.

Reference should be made to Q 20.401 of 10 CFR Part 20, 5 40.61 of 10 CFR Part 40, and paragraph D. lMPLEMENTATION 70.32(b)(5) of 10 CFR Part 70 for recordkeeping requirements regarding surveys. Section 20.401 re- The purpose of this section is to provide informa-quires that the licensee maintain records in the same tion to applicants and licensees regarding the NRC units used in 10 CFR Part 20. Thus external exposure staff's plan for using this regulatory guide. This rates should be recorded in estimated maximum dose guide reflects practices currently acceptable to the equivalent units, rem or millirem, to relevant parts of NRC staff. Except in those cases in which the the body as specified in i 20.101 of 10 CFR Part 20. applicant or licensee proposes alternative practices or Air concentrations and surface contamination meas- methods for complying with specified portions of the urement results shoold be recorded in microcuries Commission's regulations, the practices or methods

( Ci) per milliliter (ml) or 100 square centimeters described herein will be used as a basis for evaluating (cm 2), respectively. The intake of radioactive mate- applications for specific licenses for enriched

) rial should be recorded in terms of microcuries uranium processing and fabrication of uranium fuel (micrograms may be used for U-234, U-235, and or (in conjunction with inspection of performance)

U-238) and percentage of tiie applicable limit, for evaluating survey programs established by Methods used to calculate intake quantities from licensees.

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TA2LE 1 SURVEY FREQUENCIES External Removable Radiation Surface Contamination Plant Areas Surveys Air Sampling Surveys Uranium receiving, Monthly Continuous air sampling; Monthly and following '

warehousing, shipping, samples changed weekly any indication of and following any indi- releas cation of release leading to airborne concentrations of uranium.

Active processing areas Monthly Continuous air sampling *; Weekly and following UFs vaporization, samples changed each shift, any indication of UFn-UO2 conversion, following any change in release chemical processing, equipment or process control, scrap recovery, and following detection of powder processing, any event that may have rod loading, released uranium, i.e.,

decontamination, leakage (valves, pipes, tanks, waste processing, trays), spillage, or blockage change rooms. of process equipment (con-veyors, elevators, hoppers).

Chemical-metallurgical Monthly Continuous air sampling; Weekly laboratory, samples changed each shift.

Fuel assembly, inspection, Monthly Continuous air sampling; Monthly storage. {

samples changed weekly.

Lunch rooms, cafeterias, Quarterly -

Daily siiack bars, vending machine areas.

4

• See Regulatory Position C I.1 TABLE 2 SURFACE CONTAMINATION LEVELS IN ENRICHED URANIUM PROCESSING AND LWR FUEL FABRICATION PLANTS Limit ( Alpha Activity) dpm/100cm2 Removable Controlled areas 5,000 Protective clothing 1,000 worn only in controlled area Uncontrolled areas onsite 200 Personal clothing 200 (worn outside restricted area)

Skin 0*

• See Regulatory Position c. I,6 and footnote.

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REFERENCES *

1. Natbnal Commission on Raem.ogical Protection 6. IAEA Safety Series No.1, " Safe Handling of (NCRP) Report No. 8, " Control and Removal of Radionuclides," 1973 Edition, Code of Practice

/

\ Radioactive Contamination in Laboratories," De- Sponsored by the International Atomic Energy

" cember 15, 1951. Agency (IAEA) and the World Health Organiza-tion (WHO),1973*

, NCRP Report No.10, " Radiological Monitoring Methods and Instruments," April 7,1952 (re. 7. IAEA Technical Report Series, No.133, " Hand-vised edition to be published in 1978). book on Calibration of Radiation P.atection Monitoring instruments," 1971.

3. NCRP Report No. 28, "A Manual of Radioac- .

8. International Commission on Radiological Pro-tivity Procedures," November 20,1961.

tection (ICRP) Publication 12. " General Princi.

. 4. International Atomic Energy Agency (IAEA) pies of Monitoring for Radiation Protection of Technical Report Series No.120, " Monitoring Workers." Pergamon Press,1969.

f of Radioactive Contamination on Surfaces,"

9. Diegl,11., " Guidelines for Determining Fre-1970.

quency of Wipe Samples," Health Physics Op- i

5. IAEA Safety Series No. 38, " Radiation Protec- erational Monitoring, Vol. I, C. A. Willis and .l. <

I tion Procedures," 1973. S. Handloser, Eds., Gordon and Breach, New

• lAEA Reports may be obtained from UNIPUB, Inc., P.O. Bost York,1972, 433, New York, N.Y.10016. NCRP Reports may be obtained from NCRP Publications, P.O. Box 4867. Washington. D.C.

10. Sommers, J. F., " Sensitivity of G-M and Ion 20014. ICRP Reports may be obtained from Pergamon Press, Chamber Beta-Gamma Survey Instruments,"

Maxwell House, l'airview Park, Elmsford, New York 10523. Heahh Physics 28, 755,1975.

rs (U) l rh L/

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