Regulatory Guide 8.23

Radiation Safety Surveys at Medical Institutions

ML13064A091
Person / Time
Issue date:	02/28/1979
From:	NRC/OSD
To:
References
RG-8.023
Download: ML13064A091 (14)

U.S. NUCLEAR REGULATORY COMMISSION February 1979 REG ULATO RY G U [D 0j"E

OFFICE OF STANDARDS DEVELOPMENT

REGULATORY GUIDE 8.23 RADIATION SAFETY SURVEYS AT MEDICAL INSTITUTIONS

A. INTRODUCTION

Surveys t are a necessary supplement to personnel monitoring, which measures individual radiation ex- Paragraph 20.201(b) of 10 CFR Part 20, "Stand- posures by the use of devices worn b, the workers ards for Protection Against Radiation," requires that (Refs. 3, 5, 6, 8, and 9).

each licensee make or cause to be made such surveys as may be necessary for him to comply with the regu- C. REGULATORYAPOSITI N,

lations in Part 20. As used in Part 20, the term "sur- vey" means an evaluation of the radiation hazards Methods and procedureI uuide are accept- incident to the production, use, release, disposal, or able to the NRC staff4r estab,1jshJmg acceptable sur- presence of radioactive materials or other sources of vey programs in aceordane wrlT the as low as is rea- radiation under a specific set of conditions. This sonably achievnbep ( RApq'hilosophy. Generally, guide identifies the types and frequencies of surveys medical instituti n'Žs icenseod by the NRC should have that are acceptable to the NRC staff for use in medi- a health,(s cs a Aivailable for consultation to de- cal institutions licensed by the NRC to use radioac- sign - surv'IT\-p am appropriate to the institution's tive materials for purposes of diagnosis, therapy, or usei dioa& 1tie material.

research.

Tgý pesaf Surveys

B. DISCUSSION

1týGineral Description Surveys are considered to be part of a comrrreen- Surveys performed in compliance with §20.201 of sive protection program established by iceln l 10 CFR Part 20 should include those necessary to consistent with the philosophy and princil),les of eg- evaluate external exposure to personnel, surface con-

1 tamination levels, and concentrations of airborne ulatory Guide 8.10, "Operating Philosoph 4or in- taining Occupational Radiation Exposures A ,w As radioactive materials in the facility and in effluents Is Reasonably Achievable. " rinciples, methods, and from the facility.

instrumentation for carryiie.g iut radiation and con- Environmental monitoring is beyond the scope of tamination surveys we!d(e: ped early in the this guide. However, the radiation safety program atomic energy progriar. andtlhave been discussed in should include surveys or records that indicate con- reports of the Nafjonai loounc on Radiation Protec- trol of the quantities of radioactive material released tion and Meabure 'ent,_,1(1-*RP) (Refs. 1-3), the In- in air and water to unrestricted areas, as required by ternational ' y Agency (IAEA) (Refs.

4-8), and thf Iýiternational ical Protection &!CRP) (Ref.Commission on Radiolog- The word "survey,' often used synonymously with "'surveil-

9). More recent reports lance," "monitoring, or "area monitoring," is used in this (uide to connote the personal inspection of various locations in (Refs. 10-14) contain additional information for use a facility using radioactive materials, with or without accom- in establishing radiation survey programs and select- panying measurements, to determine the effectiveness of meas- ing methods and equipment for their implementation. ures to protect against exposure to radiation.

USNRC REGULATORY GUIDES Comments should be sent to the Secretary of the Commission, U.S. Nuclear Regulatory Commission, Washington, D.C. 20555, Attention: Docketing and Regulatory Guides are issued to describe and make available to the public Service Branch.

methods acceptable to the NRC staff of implementing specific parts of the Commission's regulations, to delineate techniques used by the staff in evalu- The guides are issued in the following ten broad divisions:

ating specific problems or postulated accidents, or to provide guidance to applicants. Regulatory Guides are not substitutes for regulations, and com- 1. Power Reactors 6. Products pliance with them is not required. Methods and solutions different from those 2, Research and Test Reactors 7. Transportation set out in the guides will be acceptable if they provide a basis for the findings 3. Fuels and Materials Facilities 8. Occupational Health requisite to the issuance or *continuance of a permit or license by the 4. Environmental and Siting 9. Antitrust and Financial Review Commission. 5. Materials and Plant Protection 10. General Comments and suggestions for improvements in these guides are encouraged Requests for single copies of issued guides (which may be reproduced) or for at all times, and guides will be revised, as appropriate, to accommodate com- placement on an automatic distribution list for single copies of future guides ments and to reflect new information or experience. However, comments on in specific divisions should be made in writing to the U.S. Nuclear Regulatory this guide, if received within about two months after its issuance, will be Commission, Washington, D.C. 20555, Attention: Director, Division of particularly useful in evaluating the need for an early revision. Technical Information and Document Control.

Part 20. In many medical institutions, surveys of radioactive materials. These personal surveys are par- effluents or calculations to ensure that permissible ticularly appropriate in nuclear medicine activities.

concentration limits are not exceeded are included as Personnel should be properly instructed in conducting a regular part of the health physics survey program. such surveys and should perform the surveys each Often these calculations may be made by estimating day during and after work with radioactive materials, the amounts of radioactive material washed down des- as necessary to determine the need to limit worktime ignated sinks and dividing them by the quantities of and to use protective procedures to reduce exposures sewage released from the hospital, as indicated on the as far below the paragraph 20. 101(a) limits as is rea- hospital's water or sewage bills. This procedure nor- sonably achievable. The survey results obtained by mally suffices to show compliance with the effluent these workers need not be recorded. However, the limits of Part 20. Amounts of radioactive material re- Radiation Safety Office should maintain records to leased in air within hospitals, or exhausted to the out- show that the appropriate training for, and implemen- side from hospitals, are generally small but may tation of, the worker survey program has been pro- sometimes be estimated by calculational techniques if vided and is a continuing part of the survey program.

not by air-monitoring procedures. Appendix A to this Workers should be instructed to report unusual sur- guide describes surveys to be made of radioactive vey findings to the Radiation Safety Officer.

xenon-133 releases. Surveys are not acceptable for routine compliance Radiation protection programs should include the with the personnel monitoring requirements of types of surveys discussed below. §20.202. However, in the event of accidental loss of personnel dosimetry data, e.g., as a result of losing

1.2 Surveys of External Radiation Exposure the dosimeter or chemical or physical damage to the Levels dosimeter, the best alternative means of estimating Areas to be surveyed should include any locations the exposure may be to use survey data in conjunc- where individuals may.be exposed to radiation inten- tion with appropriate occupancy factors. In such sities that might cause the occupational radiation dose case, the estimate, including the survey data used, to exceed 10 percent of the limits of paragraph should be documented and retained indefinitely (see

20.101(a) in any calendar quarter or where an indi- paragraph 20.401(c)(2)(ii)). Survey results should vidual is working with any radiation source that could be reviewed carefully by the Radiation Safety Officer produce radiation levels greater than 1.0 mR/h at 1 to identify potentially hazardous situations and un- meter. These areas typically include shipping and re- favorable trends.

ceiving areas; isotope laboratories in nuclear medicine; diagnostic areas in nuclear medicine; in- 1.3 Measurements of Radioactive Material Con- tracavitary source preparation areas in radiation ther- centrations in Air apy; patients' rooms where treatments are given with It may often be sufficient in medical institutions to intracavitary, interstitial, or radiopharmaceutical show by calculation, together with monitoring of ven- therapy sources; operating rooms: control (console) tilation rates, that air concentrations are well below areas for teletherapy equipment rooms; waste pack- levels that would require routine air sampling. How- aging and disposal areas; radiation instrument cali- ever, concentrations of radioactive material in air bration areas; and any other areas where persons might should be measured, at frequencies specified in Sec- be exposed (e.g., areas occupied by technologists, tion C.2. for areas where operations could expose nursing staff, visitors, patients, or any other persons workers to 10 percent or more of the concentration who may be exposed to radioactive materials handled values given in Table 1, Column 1, of Appendix B to by others). 10 CFR Part 20. Special requirements for such Preoperational, routine, and special surveys of monitoring may also be made a condition of the these areas should be performed by the radiation pro- license.

tection staff as described in Section C.2 of this guide. Air samples obtained in accordance with §20.103 Results of these surveys should be recorded as de- should be representative of the air in the workers'

scribed in Section C.3. In addition to this survey pro- breathing zone. In cases where breathing zone sam- gram, the Radiation Safety Officer should institute pling is not accomplished, air samples taken outside and maintain a program of surveys performed by the breathing zone closer to the source, where the workers other than health physics personnel who may concentration of radioactive material can or is ex- be exposed to external radiation levels that could ex- pected to be equal to or greater than the concentration ceed any of the limits of paragraph 2 0.101(a). Sur- in the breathing zone, are acceptable. When measur- veys by such workers may consist of no more than ing the quantity of radioactive material deposited on occasional instrument observations during work with an air sample filter, corrections should-be made for

8. 23- 2

absorption of alpha or beta particles by the filter The collection of smear samples may be pre- media and by material collected on the filter. The ceded by a rapid survey with a portable, thin-end- quantity of air that has passed through the filter window detector in order (a) to ensure that gross should be accurately measured and corrections made contamination levels are not already too high for for any loss of flow rate due to the accumulation of counting with sensitive equipment, (b) to minimize material on the filter. (in some cases) the chance for inadvertent, spread of Continuous breathing zone or general air sampling contamination by the contamination survey or other should be conducted while the work is in progress activities to be performed in the meantime, and (c) to unless experience with sample results or calculations determine which areas require greater attention in has demonstrated that the concentration of radioac- smear testing. The instrument used for this purpose tive material in the breathing zone is not likely to should have a short time constant on the order of 1 exceed 25 percent of the values given in Table 1, second or less to facilitate detection.

Column 1, of Appendix B to 10 CFR Part 20. The A standardized method for smear testing of a use of personal (lapel) samplers is acceptable for relatively uniform area should be used in order to breathing zone sampling. If the air sampling is not allow comparison of relative levels of contamination continuous, the frequency and the times selected for at different times and places. A dry smear taken from the sampling should be based on the nature of the an area of about 100 cm 2 is acceptable to indicate process involved and the probability that airborne levels of removable contamination.

radioactive material will be present. When assessing A layout diagram for each laboratory routinely this probability is difficult, frequencies based on in- surveyed is helpful for recording survey results in a formation given in Section C.2 and Table I of this uniform manner to aid review and observation of guide are acceptable. trends and for satisfying regulatory requirements for availability of survey records. On these diagrams, it

1.4 Surface Contamination Surveys is helpful to specify key locations that are smear tested at each survey and also to provide space re- Regular surveys for radioactive contamination that minding the recorder to include:

could be present on surfaces of floors, walls, furnish- ings, and equipment are a necessary part of the sur- a. Contamination levels converted to radioactiv- vey program. Any surveys carried out in accordance ity units specified in 10 CFR Part 20,

with NRC license conditions will be considered con- sistent with the level of safety provided by recom- b. Make and model number of the instruments mendations in this guide. used in the survey and in counting the smear Control of surface contamination is necessary to samples, limit external dose rates and the resuspension of loose c. Disintegration rate of each instrument test or radioactive materials that may enter the body through calibration source, inhalation, ingestion, or skin absorption.

d. Sample, backgrbund, and test counts and

1.4.1 Removable Contamination times, and For the purposes of this guide, removable con- e. Signatures at the bottom of each page.

tamination means radioactivity that can be transferred from a surface to a smear test paper by rubbing with Provision should also be made on the diagram for moderate pressure. Information is available on the recording an instrument check with an appropriate selection and use of instruments for performing re- check or calibration source for each batch of smear movable surface contamination surveys appropriate to samples counted.

the radionuclides used in medical institutions (Refs. The surveys discussed above are regularly

1-14). Methods and instruments used in surface scheduled and recorded on the survey diagrams. In contamination surveys should be sufficiently sensi- addition, it may be necessary to conduct more fre- tive to detect the nuclides being monitored (Refs. quent, informal, and unrecorded surveys in nuclear

11-14). For optimum detection of low-energy beta medicine areas or other areas where loose radioactive emitters (e.g., H-3 and C-14) as well as of alpha contamination may occur. Such surveys can be made emitters and low-energy x- or gamma-ray emitters with a thin-end-window (less than 2 mg/cm 2) detector (e~g., 1-125), liquid scintillation counting or internal held close to a smear sample immediately after it is proportional counting is normally necessary with the taken in the working area. When ambient external use of appropriate constancy checks on counter effi- radiation levels in the laboratory are low enough to ciency. maintain external radiation exposures below the lim-

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its of paragraph 20.101(a), any appreciable surface tion Safety Office. A member of the radiation safety contamination can be detected by simply holding the staff should then survey and supervise any necessary detector in a fixed position and moving the smear decontamination or clothing disposal. The applicant sample close to and away from the detector several may propose and justify protective clothing contami- times. This method may be used for the vast majority nation limits considered adequate for use in each re- of radionuclides used in diagnostic and therapeutic stricted area. The limits on line 4 of Table 2 are ac- medical practice. ceptable to the NRC staff and need not be justified by Part 20 does not specify limits for surface con- the licensee or applicant.

tamination. Each applicant may propose and justify Contamination levels observed and procedures fol- what removable surface contamination limits will be lowed during survey and decontamination of personal allowable before decontamination will be performed. clothing should be recorded. The written record These limits should be based on the need to avoid should include the names of persons surveyed, a de- transfer of si2nificant amounts of contamination to scription of prior work activities, the probable unrestricted areas and to maintain exposures as low causes, steps taken to reduce future incidence of con- as is reasonably achievable. The contamination limits tamination, times and dates, and the surveyor's signa- for restricted areas presented on line 2 of Table 2 of ture. This information may be entered in a logbook.

this guide are acceptable to the NRC staff and need Individual worker surveys of themselves need not be not be justified by the licensee or applicant. routinely recorded unless the limits on line 4 of Table

2 are exceeded. The radiation safety staff should

1.4.2 Fixed Contamination conduct spot-checks monthly to ensure that the work- ers continue their own personal contamination sur- For the purposes of this guide, fixed contamina- veys.

tion means radioactivity remaining on a surface after In restricted areas with little potential for surface repeated decontamination attempts fail to signifi- contamination, personal clothing is often worn be- cantly reduce the contamination level. A total con- neath protective clothing. Such personal clothing tamination survey, using instruments suitable for the should be surveyed by the wearer before he or she radionuclides involved, should be conducted simul- leaves the restricted area. (However, this is neither taneously with each removable contamination survey. practicable nor necessary for employees working with The applicant may propose and justify what total con- only microcurie quantities of tritium or carbon-14.)

tamination limits will be allowable for both restricted Workers should be instructed to report the situation to and unrestricted areas before decontamination will be the Radiation Safety Office when personal clothing performed. The limits appearing on line 2 of Table 2, contamination levels exceed preselected limits. A

multiplied by a factor of 5, are acceptable to the NRC member of the radiation safety staff should then sur- staff and need not be justified by the licensee or vey and supervise any necessary decontamination or applicant. clothing disposal. The applicant or licensee may pro-

1.5 Protective and Personal Clothing Contamina- pose and justify personal clothing contamination lim- its; the limits given on line 3 of Table 2 are accept- tion Surveys able to the NRC staff and need not be justified by the Individuals working in areas where a potential for applicant or licensee. Records should be maintained skin or clothing contamination exists should be pro- in the same manner as those for protective clothing vided with suitable protective clothing. Laboratory contamination.

coats and protective gloves, as described in Refer- ences 11 and 12, are usually adequate for any proce- 1.6 Personal Surveys dures in medical institutions. Protective clothing Although personal contamination in excess of the should be surveyed by the wearer after use if signifi- value given on line 5 of Table 2 is unusual in medical cant contamination is possible. Contaminated protec- institutions, individuals who work in restricted areas tive clothing should be removed and placed in special under conditions in which they may become contami- laundry containers before leaving a restricted work nated should survey all exposed areas of the body be- area. Disposable gloves should be discarded in fore donning personal clothing or leaving the re- radioactive waste containers. After gloves are re- stricted area. Particular attention should be paid to moved, hands should be washed and surveyed. the body, hair, bottoms of the shoes or feet, and the When protective clothing contamination levels may hands. Workers should be instructed to report the de- be expected to exceed preselected limits, workers tection of contamination on the body to the Radiation should be instructed to take care to avoid dispersal of Safety Office. Decontamination attempts, under the contamination and to report the situation to the Radia- direction of Radiation Safety Office personnel or a

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medical consultant, should be repeated until (a) such procedures should be instituted and repeated until ad- attempts cease to effect significant reductions or (b) ditional efforts do not significantly reduce contami- such attempts threaten to irritate or harm the skin .2 nation levels. The applicant or licensee may propose When decontamination attempts are terminated, there and justify total and removable contamination limits should .be no further concern if the residual contami- below which uncontrolled release of equipment is nation does not exceed preselected levels. Such levels permitted. The limits given in Table I of Regulatory may be proposed and justified by the applicant or Guide 1.86. "Termination of Operating Licenses for licensee. The limits given on line 5 of Table 2 will be Nuclear Reactors,'" are acceptable to the NRC staff accepted without justification. If residual contamina- and need not be justified by the licensee or applicant.

tion exceeds the selected limits, the affected indi- vidual may be released (since his contamination is 1.8 Ingestion now relatively fixed and not likely to enter the body), Surveillance should be included in the radiation but periodic surveys should be made until the limits safety program to ensure that workers properly ob- are no longer exceeded. The resulting dose should be serve rules to prevent ingestion of radionuclides, determined and entered in the individual's personnel e.g., rules against eating, drinking, or smoking in dosimetry record. Complete records should be main- work areas or while wearing potentially contaminated tained of each incident of this nature. clothing; storing foods in work areas; pipetting by Since medical personnel may often handle open mouth; and wearing contaminated laboratory coats to vials or containers with millicurie or higher levels of the cafeteria or other unrestricted areas. Water foun- volatile forms of certain nuclides such as 1-125, tains close to radioactivity work areas should be

1-131, and Tc-99m, which in certain forms may con- smear tested regularly.

centrate in the thyroid or other body organs, bioassay monitoring is sometimes made a condition of the 1.9 Surveys of Packages Received and Packages license. Acceptable criteria for such programs are Prepared for Shipment published in other guides and are available from the External radiation measurements and tests of ex- License Management Branch. In addition to these ternal surfaces of packages received or packaged for programs, placing the detector against the neck close shipment should be carried out near the receiving or to the thyroid is often useful for monitoring for inter- packaging point to avoid unwarranted radiation expo- nal deposition of these nuclides during surveys for sures and inadvertent contamination of personnel or skin contamination; however, for 1-125 a thin crystal the hospital. Surveys and labeling must comply with scintillation probe would be needed to obtain the NRC's regulations (see §§20.203, 20.205, 32.19, adequate sensitivity. In this way, appropriate person- and 32.70 through 32.74 of 10 CFR) and with any nel may be more frequently monitored for internal specific license conditions. Delivery of packages exposure while they are also being monitored for ex- within the hospital should also be monitored. Any de- ternal contamination. Any positive indications from livered containers of radioactive material must be these types of surveys should be recorded in the radi- labeled, as required by paragraph 20.203(f). All ation safety logs. Indications of internal depositions packages bearing yellow I or yellow III labels should should be reported to the Radiation Safety Office. be transported by cart. Only adequately shielded sources should be transported. Internal containers of packages containing significant amounts of radioac-

1.7 Surveys of Equipment Prior to Release to Un- tive materials should not be opened until the contain- restricted Areas ers have been placed in the appropriate protective Before the uncontrolled release of potentially con- facility (e.g., hood).

taminated medical instruments or equipment from re- All personnel, including security guards, should be stricted to unrestricted areas, surface contamination adequately instructed in performing at least an initial surveys should be conducted on such instruments and inspection survey for leakage, or damage, before equijment for both removable and fixed contamina- transporting any packages of radioactive materials tion. If contamination is detected, decontamination through hospital areas. The instructions should clearly indicate which packages should be transported

2 Decontamination attempts without supervision or instruction by cart rather than hand-carried.

from the licensee's medical consultant should be restricted to washing with mild soap and water unless other safe procedures 1.10 Checks on Posting of Caution Signs, Labels, have already been approved and personnel have been properly Signals, Controls, and Notices to Employees instructed in applying them. If such attempts do not reduce the contamination to acceptable levels, the aid of the licensee's The radiation safety staff should perform surveil- medical consultant should be obtained. lance at least weekly to ensure that signs, labels,

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radiation alarm signals, other access controls, and re- in the radiation safety records system. A posted graph quired Notices to Employees, copies of licenses, and for each source is convenient, helpful in avoiding otiier items are properly posted, legible, and opera- calculational errors, easily available for inspection, tive, as required by 10 CFR Part 19, "Notices, In- and acceptable for obtaining source intensity within structions and Reports to Workers; Inspections,'" and the required accuracy.

Part 20 or by license conditions. Radiation alarm sig- A calibration should be performed after each nals should be routinely tested for operation by use of maintenance adjustment or repair, and no less fre- appropriate check sources to ensure proper function- quently than at 12-month intervals, by exposing the ing of the alarms. Microswitches on which these in- instrument to an appropriate field of radiation and struments depend for operation should also be tested checking the response of the instrument at a to ensure that they will function reliably in normal minimum of two points near '/3 and 2/3 of full scale.

operations or as expected under emergency condi- The readings obtained from the calibration verifica- tions. Care should be taken to minimize exposure to tion should be recorded, preferably by plotting the personnel from the tests themselves. Any signs, reading on the instrument calibration curve where ap- labels, or notices found to be missing should be plicable. Other instruments should be calibrated at promptly provided. Temporary signs, signals, or bar- frequencies suggested by the manufacturer. Check riers, together with appropriate worker notification sources should be used to check the continued accu- and instruction, may be used in the interim when racy of all instruments each time they are used in the items specified in Parts 19 and 20 are not available, field, preferably before and after each series of meas- but acceptable corrections should be provided as soon urements. (See also Regulatory Guide 10.8., "Guide as practicable. for the Preparation of Applications for Medical Pro- grams. ")

1.11 Leak Tests of Sources Sealed sources containing (a) more than 100 mi- 1.13 Surveys of Protective Clothing Before and crocuries of a byproduct material with a half-life of After Laundry more than 30 days (except iridium-192 seeds encased Surveys of protective garments and linens should in nylon ribbon) (see paragraph 35.14(b)(5)) or (b)

be performed prior to release to a conventional laun- more than 10 microcuries of an alpha emitter (see paragraph 31.5(b)(2)(ii)) must be leak tested for con- dry'. Garments and linens should be released to such a tamination or leakage at intervals not to exceed 6 laundry only if contamination levels do not exceed months unless a different interval is specified for a those given on line 3 of Table 2. Items contaminated particular manufactured source under the provisions with short-half-life material that exceeds the levels of paragraph 32.74(b) of 10 CFR Part 32, "Specific given on line 3 of Table 2 should be contained in Domestic Licenses to Manufacture or Transfer Cer- leakproof bags arld transported in carts to controlled tain Items Containing Byproduct Material." Further storage areas for decay'. Items contaminated with provisions and exceptions to leak-testing require- long-half-life material may be disposed of as radioac- ments are established in paragraphs 35.14(b) and tive waste or sent for decontamination to a laundry

35.14(e)(1) of 10 CFR Part 35. Any specific license licensed by the NRC or by an Agreement State.

conditions must also be followed.

1.12 Calibration and Source Checks of Radiation 1.14 Ventilation Surveys Safety Instruments Where enclosures such as fume hoods are used to Portable survey instruments should be calibrated at protect workers from unencapsulated radioactive least annually to within +/-1 0 percent (or _+/-20 percent material, measurements of the face velocity at the en- with a calibration curve supplied) of two points (at a closure entrance should be made and recorded quar- minimum) at approximately 1/3 and 2/3 of each scale terly to ensure that the airflow is adequate. 3 Such in order to examine readability, operability, and ac- measurements should be made by using a properly curacy. Instruments should be calibrated with radia- calibrated thermoanemometer or velometer to deter- tion sources of appropriate emission and intensity. mine whether the airflow has been reduced to unac- Each source used for calibration should be certified in ceptable levels by filter loading or by the malfunction radioactivity content to within 15 percent by the of blowers, fans, etc. The minimum average face supplier, as recommended by the International Com- velocity for a fume hood with the sash in the operat- mission on Radiological Units and Measurements (Ref. 15), and should be corrected for decay as of the I Where filtered exhausts are employed, devices such as U-tube manometers should be provided to indicate the pressure drop day on which the source is used for survey instrument across the filters, thus affording an early indication of airflow calibration. All decay corrections should be included loss at enclosures.

8.23-6

ing position or for an opening in a special enclosure mine whether they comply with the requirements of should be 100 ft/min, as determined from at least five §20.105 of 10 CFR Part 20.

different measurement points. Corrective action should be taken as soon as possible when the face 1.16 Surveillance velocity is found to be deficient.

1.16.1 Surveillance by Individual Performing

1.15 Surveys in In-Hospital Unrestricted Areas Surveys Unrestricted areas should be surveyed periodically The term "surveillance," as used in this sec- to ensure that radiation and radioactive material are tion, refers to observations of radiological working adequately confined in restricted areas, except in conditions in restricted areas made by the person who cases where these materials must be transported be- performs the routine radiation and contamination sur- tween areas. Recommendations in References I1 and veys. Such surveillance is one of the more important

12 should be followed when transporting radioactive aspects of a radiation protection program. Through materials or patients emitting radiation from licensed surveillance, radiation safety personnel acquire de- radioactive materials through hallways or other unre- tailed knowledge of each operation as necessary (a)

stricted areas of the hospital. Such transportation to identify ways of preventing or minimizing occupa- should be surveyed and planned with a member of the tional exposures, (b) to select appropriate times for radiation safety staff. making radiation safety measurements, and (c) to

1.15.1 Surface Contamination Surveys adequately prepare for emergency conditions. Radia- tion safety personnel should be sufficiently familiar Removable surface contamination surveys in un- with each activity to explain it in detail, to describe restricted areas in which unencapsulated radioactive potential hazards and the precautions taken to materials are used or where contamination may be minimize exposures, and to discuss how this knowl- likely to occur should be performed and recorded at edge of procedures within each activity has influ- frequencies consistent with the potential for spreading enced the selection of appropriate times for perform- contamination but no less frequently than quarterly.

ing radiation safety measurements.

Random smear testing of floors alone is acceptable for most unrestricted areas. In cafeterias and snack bars, furniture and equipment, as well as floors, should also 1.16.2 Regular Inventory of Radioactive Mate- be surveyed. If such surveys reveal that radioactive rial, Audit of Procedures, and Instruc- contamination is being transferred out of restricted tion of Personnel areas, immediate corrective action should be taken to eliminate such transfers. Decontamination efforts The surveillance program includes:

should be repeated until it is evident that subsequent a. Regular inventory of radioactive materials and efforts would not significantly reduce contamination their locations, levels. If contamination is found, unrestricted areas should be surveyed more frequently (e.g., daily or b. Frequent audits of radiation safety procedures weekly) until a trend of negative results is again es- and the uses and amounts of material in process com- tablished. The applicant or licensee may propose and pared to licensed possession limits, and justify permissible contamination levels, following de- c. Discussions with personnel to ensure their contamination efforts described above, for unrestricted continued awareness of safety procedures and the ap- areas. The limits given on line I of Table 2 are accept- propriateness of their instruction and training for the able to the NRC staff and need not be justified by the tasks they are performing.

licensee or applicant. These surveillance activities may be performed during the performance of other survey measurements

1.15.2 Radiation Surveys or tests. The surveillance should be performed at Radiation surveys in unrestricted areas adjacent to least annually by the Radiation Safety Officer, in the restricted areas should be performed and recorded at presence of a management representative, as a man- frequencies consistent with the types and quantities of agement audit. The management audit should be material in use but no less frequently than quarterly. comprehensive enough to provide management with These surveys should be made in areas adjacent to re- an awareness of the nature and importance of ac- stricted areas and, when exposures may occur, in all tivities conducted for personnel protection and hos- areas through which radioactive materials are trans- pital safety. A sample checklist that can be useful in ferred and temporarily stored before shipment. Radia- auditing as well as in carrying out radiation surveys is tion levels in these areas should be evaluated to deter- presented in Appendix B.

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2. Frequency of Surveys parts of the body as specified in Part 20. Air concen- tration measurement results should be recorded in The frequency of routine surveys depends on the units of uCi/ml, and surface contamination meas- nature, quantity, and use of radioactive materials, as urement results should be recorded in units of well as the specific protective facilities, equipment, dpm/100 cm 2 or tkCi/100 cm 2 (or as in §20.5).

and procedures that are designed to protect the Record retention requirements are specified in the worker from external and internal exposure. regulations cited above. Paragraph 20.401(c)(2) re- Generally, surveys should be performed before quires that survey records be preserved for 2 years, radioactive materials are used in a new procedure and except that records of air monitoring and (in the ab- area in order to establish a baseline of background sence of personnel monitoring data) records of sur- radiation levels and radioactivity from natural veys to determine external radiation dose (see para- sources, including structural components of the facil- graph 20.401(c)(2)(ii)) are to be maintained until ity, and any already existing operations with radia- the NRC authorizes their disposition.

tion sources in nearby rooms or facilities. These Records may be maintained in logbooks or on spe- baseline surveys should be performed under the vari- cial forms as long as they are clear, legible, under- ous conditions to be expected in routine hospital pro- standable, and authenticated by authorized personnel.

cedures. The signature of the person making the record and the Surveys should be repeated after routine proce- date should be on the same page as the record and dures begin with normal levels of radioactive material should immediately follow each record entry. Either and with potentially exposed persons present and car- the original or a reproduced copy or microform (duly rying out their functions. Surveys should also be authenticated) may be maintained to meet the storage conducted after significant changes in the quantities requirements of §20.401.

of radioactive material handled or in the quantities present at any one time or after changes in protective equipment or procedure

D. IMPLEMENTATION

Although the frequencies of routine surveys de- pend on many factors, as stated above, and should be The purpose of this section is to provide informa- designed for the specific medical practices and tion to applicants and licensees regarding the NRC

facilities involved to maintain exposures as low as is staff's plan for using this regulatory guide.

reasonably achievable (ALARA), minimum fre- Except in those cases in which the applicant or quencies acceptable to the NRC staff for meeting the licensee proposes an acceptable alternative method requirements of §20.201 of 10 CFR Part 20 are given for complying with specified portions of the Com- in Table I of this guide. mission's regulations, the staff will use the methods described herein after October 1, 1979, in evaluating

3. Records of Surveys applications for specific materials licenses for medi- Referenice should be made to §§20.401 and 30.51 cal institutions or (in conjunction with inspections of and to 10 CFR Parts 31-35 for recordkeeping re- performance) for evaluating survey programs estab- quirements regarding surveys related to the receipt, lished by licensees.

use, packaging, transfer, and disposal of byproduct If an applicant or licensee wishes to use the method material. Section 20.401 requires that licensees main- described in this regulatory guide on or before Oc- tain records in the same units used in Part 20. Thus, tober 1, 1979, the pertinent portions of the applica- external exposure rates should be recorded in esti- tion or the licensee's performance will be evaluated mated maximum dose equivalent units to relevant on the basis of this guide.

8.23-8

TABLE I

SURVEY FREQUENCIES

1. All elution, preparation, and injection areas should be surveyed daily with a survey meter and decontami- nated if necessary.

2. Laboratory areas where only small quantities of radioactive material (less than I millicurie) are used should be surveyed monthly.

3. All other laboratory areas should be surveyed weekly.

4. The weekly and monthly surveys should consist of:

a. A measurement of radiation levels with a survey meter sufficiently sensitive to detect 0.1 mR/h.

b. A series of smear tests to measure contamination levels. The method for performing smear tests should be sufficiently sensitive to detect the limits in Table 2 to one significant digit.

c. Any air sample measurements necessary to determine compliance with §20.103 of 10 CFR Part 20 in cases where calculations alone are not sufficient.

TABLE 2 LIMITS FOR REMOVABLE SURFACE CONTAMINATION IN MEDICAL INSTITUTIONS*

Type of Radioactive Material**

Type of Surface Alpha Emitters Beta or X-Ray Emitters Low-Risk Beta or X-Ray

(/xCi/cm 2) (,Ci/cm 2 ) Emitters (,Ci/cm2 )

1. Unrestricted areas 10-1 10-6 10-5

2. Restricted areas 10-6 10-5 10-4

3. Personal clothing worn 10.1 10-6 10-5 outside restricted areas

4. Protective clothing worn 10.6 10-1 10-4 only in restricted areas

5. Skin 10-6 10-6 10-s

• As adapted from Table I of Reference 4. Averaging is acceptable over inanimate areas of up to 300 cm2 or, for floors, walls, and ceiling, 100

2 2 2 cm . Averaging is also acceptable over 100 cm for skin or, for the hands, over the whole area of the hand, nominally 300 cm .

• • Beta or x-ray emitter values are applicable for all beta or x-ray emitters other than those considered low risk. Low-risk nuclides include C-14, H-3, S-35, Tc-99m, and others whose beta energies are <0.2 MeV maximum, whose gamma or x-ray emission is less than 0. 1 R/h at 1 meter per curie, and whose permissible concentration in air (see 10 CFR Part 20, Appendix B, Table I) is greater than 10-6 pbCi/ml.

8.23-9

REFERENCES*

I National Commission on Radiological Protection 8. IAEA Safety Series No. 25, "Medical Supervi- (NCRP) Report No. 8, "Control and Removal of sion of Radiation Workers,"' sponsored jointly by Radioactive Contamination in Laboratories," is- IAEA. WHO, and ILO, 1968.

sued December 15, 1951.

9. International Commission on Radiological Pro-

2. NCRP Report No. 9, "Recommendations for tection (ICRP) Publication 12, "General Princi- Waste Disposal of Phosphorus-32 and Iodine-131 ples of Monitoring for Radiation Protection of for Medical Users," issued November 2, 1951. Workers," Pergamon Press, 1969.

3. NCRP Report No. 10, "Radiological Monitoring 10. AAPM Monograph No. 1, "Biophysical Aspects Methods and Instruments," issued April 7, 1952 of the Medical Use of Technetium-99m," J. G.

(revised edition to be published in 1978). Kereiakes and Karen R. Corey, Editors (available

4. International Atomic Energy Agency (1AEA)

from American Association of Physicists in Technical Report Series No. 120, "Monitoring Medicine, Dr. James G. Kereiakes, E555 Medi- of Radioactive Contamination on Surfaces." cal Sciences Building, University of Cincinnati,

1970. Cincinnati, Ohio 45267), 1976.

11. NCRP Report No. 48, "Radiation Protection for

5. IAEA Safety Series No. 38, "Radiation Protec- Medical and Allied Health Personnel," issued tion Procedures,~ 1973.

August 1, 1976.

6. IAEA Safety Series No. I, -Safe Handling of

12. NCRP Report No. 37, "Precautions in the Man- Radionuclides,'" 1973 Edition, Code of Practice agement of Patients Who Have Received Sponsored by the International Atomic Energy Therapeutic Amounts of Radionuclides," 1970.

Agency (IAEA) and the World Health Organiza- tion (WHO), 1973.

13. Diegl, H., Guidelines for Determining Fre-

7. IAEA Technical Report Series No. 133, "Hand- quency of Wipe Samples,' in Health Physics book on Calibration of Radiation Protection Operational Moniloring, Vol. 1, C. A. Willis Monitoring Instruments," 1971. and J. S. Handloser, Eds., Gordon and Breach.

New York, 1972.

IAEA reports may be obtained from UNIPUB. Inc.. P.O. Box

433, New York. N.Y. 10016. 14. Sommers, J. F., "Sensitivity of G-M and Ion ICRP reports may be obtained from Pergamon Press, Maxwell Chamber Beta-Gamma Survey Instruments,

House. Fairview Park. Elmsford, New York 10523. Health Physics 28, 755, 1975.

ICRU reports may be obtained from ICRU Publications, P.O. 15. International Commission on Radiation Units and Box 30165, Washington. D.C. 20014. Measurements (ICRU) Report 12, "Certification of Standardized Radioactive Sources, Sep- NCRP reports may be obtained from NCRP Publications. P.O.

Box 4867, Washington, D.C. 20014.

tember 15, 1968.

8.23-10

APPENDIX A

SURVEYS OF RADIOACTIVE XENON-133 RELEASES

Surveys associated with the use of xenon-133 4. Emergency Procedures should be sufficient to show compliance with re- Check to determine that all personnel using quirements for protection of persons in restricted and xenon-133 have been trained in the established emer- unrestricted areas (see §§20.103 and 20.106) and gency procedures to be followed in case of an acci- with the terms and conditions of the NRC Materials dental release of xenon-133.

License. Surveys may consist of either measurements of airborne radioactivity or of calculations supported by records of xenon-133 used and measurements of 5. Air Concentrations of Xenon-133 in Restricted pertinent ventilation and air effluent volumes. The Areas procedures outlined below are acceptable for survey- Check to determine that air concentrations of ing xenon-133 concentrations in medical institutions. xenon-133 in restricted areas meet the requirements Acceptable surveys would be indicated by records of §20.103. This may be done by making physical of the following information, procedures, or condi- measurements. Alternatively, this may be done by tions: reviewing the use of xenon-133 (Item l.a above),

checking the ventilation rate in each area, and per-

1. Quantities Used forming calculations similar to those submitted with a. Verify that patient information records (Items the license application. If the results of the calcula-

1-3 below) are in order; compare with similar infor- tions indicate that air concentrations of xenon-133 (as mation submitted to NRC in support of request for averaged over one calendar quarter) approach or ex- xenon- 133. ceed 1 x 10-1 microcuries per milliliter, then the licensee should consider and implement methods of

(1) Number of studies per week. increasing ventilation rates or of reducing patient

(2) Activity administered to each patient. load.

(3) Comparison of number of studies and aver- age activity administered to each patient with infor-

6. Methods of Xenon-133 Disposal mation submitted in application.

a. Dilution through .exhaust systems b. Verify that possession limits are controlled and corrected for differences in calibration date and date Licensees who dispose of xenon-133 by release of use. Compare with license condition. to the atmosphere through an air exhaust system are required to perform surveys (i.e., measurements or

2. Survey Records for Use and Storage Areas calculations) to ensure that they are in compliance Check ventilation quarterly in all areas in which with paragraph 20.1(c) and §20.106 of 10 CFR Part xenon-133 is to be used and stored to ensure that all 20. Paragraph 20.1 (c) requires that the concentrations airflow rates are maintained in accordance with of xenon-133 in effluents to unrestricted areas be as statements made in the license application. low as is reasonably achievable by the current state of technology, and §20.106 requires that the concentra-

3. Procedures for Routine Use tions averaged over a period of 1 year should not ex- a. Check to determine that procedures being fol- ceed 3 x 10-7 microcuries per milliliter.

lowed for routine use of xenon-133 are in accordance Make physical measurements to determine com- with procedures described in license application.

pliance with §20.106 and paragraph 20.1(c). Alter- Check to determine that all personnel using xenon- natively, measure ventilation rate and, using xenon-

133 have been trained in these procedures for routine

133 data from Item L.a above, perform calculations use of xenon-133.

similar to those submitted with license application.

b. Check to determine that special apparatus for If the results indicate that air concentrations of administration and collection of xenon-133 is being xenon-133 (as averaged over 1 year) approach or ex- used, as specified in the license application.

ceed 3 x 10' microcuries per milliliter, then the c. Check to determine that special procedures are licensee should consider and implement methods of being used to reduce leakage (e.g., use of nose increasing ventilation rates, reducing patient load, or champs or special enclosures), as specified in the decreasing amount of xenon-133 released (e.g.,

license application. through use of a charcoal trap).

8.23-11

If the exhaust is released to a restricted area, and ventilation. Calculations should be made of aver- e.g.. a roof to which access is controlled, or from a a2e concentrations of xenon-133 in air at the exhaust tall stack, Sutton's equation (Refs. 1 and 2) may be and compared to the allowable limit.

used to calculate the concentrations at the nearest unrestricted area. If this approach is used, record the location of the exhaust system outlet as used for the USEFUL CONVERSIONS

calculation model, including proximity to unre- stricted areas, air intakes, and open windows. 1 mCi 103 'uCi

4 b. Adsorption onto charcoal traps 1 ft3 = 2.832X10- 2m 3 = 2.832x10 mI

1 ft 3/min = 1.699X 106 mi/h Surveys should be made to check leakage from charcoal trapping devices. If the exhaust is vented to = 6.797x 10' ml/40-h week the outdoors or other unrestricted area, check to de- = 1.484X 10 10 ml/yr termine that air concentrations of xenon-133, aver- I week = 168h aged over 1 year, do not -approach or exceed 3 x

10-1 microcuries per milliliter. See Item 6.a above.

Record measurements to check the performance REFERENCES

of collection and trapping devices according to spec- ifications, both initially and on a continuing basis. 1. Blatz, Hanson, "Radiation Hygiene Handbook,"

Include monitoring of traps to determine when sat- McGraw-Hill, New York, 1959, pp. 22-7.

uration occurs and when the filter must be replaced.

2. Cember, Herman, 'Introduction to Health Check the procedures for handling saturated fil- Physics," Pergamon Press, New York, 1969, pp.

ters, including the provisions of adequate shielding 334-9.

.23-12

APPENDIX B

SAMPLE CHECKLIST FOR RADIATION SURVEYOR

I. Initiate contamination survey report for each lab a. Check card for previous survey results, e.g., successive red circles, nobody in.

b. Fill in name on Authorized User, Department, Building and Room Number, and Survey Date.

c. Sketch floor plan.

2. Ask lab personnel (and record answers on report form)

a. What isotopes are being used? (Compare with what User is cleared for.)

b. Where in the lab are they used?

c. Where are isotopes stored?

d. What was last order? (Compare with card record.)

e. Is Authorized User available, if needed? If not, give reason, e.g., on leave, out of country, terminated employment.

f. In what other labs are isotopes used? (Compare with card record.)

g. Where is waste stored and disposed of?

3. Check labeling a. Lab door--"Caution, Radioactive Material' (CRM).

b. Liquid waste sink--"Contaminated Liquid Waste" (survey card should indicate radioactive sink-RS).

Is sink log posted? Is it being used?

c. Radioactive hood-"Caution, Radioactive Material" (survey card should indicate radioactive hood- RH). "Air Flow Check" white label with date no older than 1 year required.

d. Refrigerator and other storage areas-'"CRM,'" including those in corridors.

e. Radioactive waste containers--"CRM'" or "Contaminated Waste" should be lined with yellow plastic bag.

f. Any area with external radiation over 2.5 mR/h should be labeled with "Caution, Radiation Area"

(CRA) and should be noted on survey form. (See paragraph 20.202(b)(2) and §20.203 of 10 CFR Part

20.)

2. 10 CFR Part 19 signs.

4. Observe general laboratory conditions a. Food and drink preparation and use in radioactive material areas.

b. Waste container overfilled.

c. Dosimeters being worn.

d. Mouth pipetting.

5. Conduct laboratory survey using portable survey meter a. Record external dose rate from accessible storage surfaces.

b. Record exposure rate from contaminated surfaces found.

6. Smear survey a. Take first smear near or in lab entrance.

b. Take several smears from floor and benches and equipment as indicated by answers to earlier questions.

7. Discuss 10 CFR Part 19 (Instruction to Workers) requirements.

8. Results a. Count smears and list results on survey form.

b. Notifylab personnel of contamination, and note on form who was called and date of notification.

c. Identify all abnormal radiation safety conditions on survey form document.

d. Complete survey card, replace in file, and mail survey form copy to User.

e. If lab has contamination (significant), call User, request cleanup, and resmear.

f. Do resmear when notified or call User if no resmear was called for.

g. File carbon copy of results form.

8.23-13

UNITED STATES

NUCLEAR REGULATORY COMMISSION POSTAGEE AND FEES PAID

WASHINGTON, D. C. 20555 U.S. NUCLEEAR REGULATORY

CO 'MMISSION

OFFICIAL BUSINESS

PENALTY FOR PRIVATE USE, $300

120555011962 1 SO

US NRC.

Or:FICE OF THE COMMISSIONERS

OR .JOSEPH HENDRIE

CHAIRMAN

H1149 WASHINGTON DC 20 555