Regulatory Guide 8.8

Information Relevant to Ensuring That Occupational Radiation Exposures at Nuclear Power Stations Will Be as Low as Is Reasonably Achievable

ML003739549
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Issue date:	06/30/1978
From:	Office of Nuclear Regulatory Research
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RG-8.008, Rev 3
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Revision 3 U.S. NUCLEAR REGULATORY COMMISSION June 1978 REGULATORY GUIDE

4 OFFICE OF STANDARDS DEVELOPMENT

REGULATORY GUIDE 8.8 INFORMATION RELEVANT TO ENSURING THAT OCCUPATIONAL RADIATION

EXPOSURES AT NUCLEAR POWER STATIONS WILL BE AS LOW AS

IS REASONABLY ACHIEVABLE

A. INTRODUCTION

high dose rates. 2 An ad hoc committee of the Na tional Council on Radiation Protection 'and Meas Paragraph 20.1(c) of 10 CFR Part 20, "Standards urements (NCRP) (Ref. t) chose in 1959 to make the for Protection Against Radiation," states that licen cautious assumptions that a proportional relationship sees should make every reasonable effort to maintain exists between dose and biological effects and that exposures to radiation as far below the limits speci the effect is not dependent on dose rate. Essentially, fied in Part 20 as is reasonably achievable. This this amounts to assumptions of a nonthreshold, guide provides information relevant to attaining goals "linear" (straight line) dose-effect relationship.

and objectives for planning, designing, constructing, operating, and decommissioning a light-water reactor The International Commission on Radiological (LWR) nuclear power station to meet the criterion Protection ICRP), the Federal Radiation Council that exposures of station personnel' to radiation dur (FRC) whose functions now reside in the Environ ing routine operation of the station will be "as low as mental Protection Agency (EPA), and committees of is reasonably achievable" (ALARA). This guide is the National Academy of Sciences/National Research also responsive to the admonition of the Federal Council (NAS/NRC) have used this hypothesis to es Radiation Council (now EPA) that occupational radi timate conservatively the number of possible biologi ation exposures be maintained ALARA. Major acci cal effects that statistically may be associated with dent situations and emergency procedures are not exposures to radiation.

within the scope of this guide. The NAS/NRC Biological Effects of Ionizing Much of the information presented in this guide Radiation (BEIR) Committee (Ref. 2) reiterated that also is applicable to nuclear power stations other than the assumptions of a nonthreshold linear relationship those cooled with light water. The applicable goals between dose and biological effects independent of and objectives should be used for all nuclear power the dose rate should be applied for radiation protec stations until more specific goals and objectives are tion purposes. This recommendation has been available for other types of power reactors. adopted by EPA (41 FR 28409) for the purpose of estimating the potential human health impact of low levels of ionizing radiation. The radiation protection

B. DISCUSSION

goal is to reduce doses wherever and whenever rea The relationship between radiation dose and sonably achievable, thereby reducing the risk that is biological effects is reasonably well known only for assumed (for radiation protection purposes) to be with current annual proportional to the dose.

doses that are high compared dose limits and only when such doses are delivered at In 1973, the ICRP (Ref. 3) stated:

• Lines indicate substantive changes from previous issue. "Whilst the values proposed for maximum permis

"Station personnel," as used in this guide, includes all per

2 Throughout this guide the word "dose" will allude to "dose sons working at the station, whether full-time or part-time and whether employed by the licensee or by a contractor for the equivalent," the term used for radiation protection purposes, licensee. with the unit expressed in "reins."

USNRC REGULATORY GUIDES Commens should be sent to the Secretary of the Commisson. US. Nuclear Regu latory Commission. Washington. D.C. 20555. Attention Docketing and Service Regulatory Guides are issued to describe and make available to the public mathods Branch.

acceptable to the NRC staff of implementing specific parts of the Commission's regulations, to delineate techniques used by the staff in evaluating specific problems The guides wre issued in the following ten broad divisions or postulated accidents, or to provide guidance to applicants. Regulatory Guides are not substitutes for regulations, and cotrmpliance with them is not required. 1. Power Reactors

6. Products

~e Mettlods and StutiOns different from thos set out in the guides witl be accept.

ftandsolutiosdifa $ ferenthefrom thous e outin

1et the guides will boneacept.

2.

3.

Research and Test Reactors Fuels and Materiatls Facilities Environmental and Siting

7.

8.

9.

Transportation Occup*atiornal Health Antitrust Review able if they proride a basis for t he findings requisite to the issuance or continuance 4.

of a permit or license by the Commssion. 5. Materials and Plant Protection 10. General Comme~ts and sugestions for improvements in thee guides are encouraged at all Requests for single copies of issued guides (which may be reproduced) or for place times, and guid*e will be revised, as appropriate, to accomemodate comments and ment on an automatic distribution list for single copies of future guides in specific to reflect new information or experience. This guide was revised as a result of divirsins should be made in wriling to the US. Nuclear Regulatory Commission.

sibstanntee comrments received from the public and additional staff revi. Washington. D.C. 20555. Attention: Director. Division of Document Control.

sible doses are such as to involve a risk which is doses among broad job categories and among the small compared to the other hazards of life, equipment systems or components that represent sub nevertheless, in view of the incomplete evidence stantial sources of exposures. Doses to station per on which the values are based, coupled with the sonnel are influenced by many variables, including knowledge that certain radiation effects are irrever the ability of fuel -lements to retain fission products, sible and cumulative, it is strongly recommended the extent of deposition of activated corrosion prod that every effort be made to reduce exposure to all ucts throughout the primary and auxiliary coolant sys types of ionizing radiation to the lowest possible tems, the reliability of other *specific equipment, the level." station layout, and radiation protection programs.

Merely controlling the maximum dose to individu If design reviews or inspections had revealed that als is not sufficient; the collective dose to the group radiation exposures at nuclear power stations were (measured in man-rems) also must be kept as low as unavoidable or that the cost of reducing the exposures is reasonably achievable. "Reasonably achievable" would be unreasonable, the exposures might be con is judged by considering the state of technology and sidered ALARA by definition. However, this has not the economics of improvements in relation to all always been the case, and this guide is intended to the benefits from these improvements. (However, a assist in achieving a status wherein exposures are comprehensive consideration of risks and benefits considered to be ALARA.

will include risks from nonradiological hazards. An action taken to reduce radiation risks should not re A major portion of the radiation exposure of sta sult in a significantly larger risk from other hazards.) tion personnel is received during maintenance, rad waste handling, inservice inspection, refueling, and Under the linear nonthreshold concept, restricting nonroutine operations (Ref. 6). The decommissioning the doses to individuals at a fraction of the applicable process also has a potential for substantial exposures limit would be inappropriate if such action would re to personnel. Effective design of facilities and selec sult in the exposure of more persons to radiation and tion of equipment for systems that contain, collect, would increase the total man-rem dose. The radiation store, process, or transport radioactive material in protection 3 community has recognized for many any form will contribute to the effort to maintain years that it is prudent to avoid unnecessary exposure radiation doses to station personnel ALARA.

to radiation and to maintain doses ALARA. In addi tion to reduced biological risks, the benefits of such Products of erosion or corrosion (i.e., "crud'" 4 )

practices may include avoidance of costs for extra that become mobile and are activated constitute an personnel to perform maintenance activities and important (perhaps principal) source of radiation with avoidance of nonproductive station shutdown time respect to the exposure of station personnel. (Crud is caused by restrictions on station personnel working in accumulated in and transported by the coolant. Some radiation areas. components of the crud become radioactive when passing through the reactor core. Migration of crud to Annual collective radiation dose equivalents re other systems occurs with coolant or steam. Specific ceived by personnel working at an LWR nuclear radionuclides that have been identified in crud and power station have ranged from less than 100 man that can contribute substantially to the radiation rems to over 5,000 man-rems (Refs. 4 and 5). Typi source are Co-58, Co-60, Mn-54, Zn-65, and Zr-95.)

cally, annual collective dose equivalents range from

400 to 1,000 man-reins at LWR stations that have Exposures of station personnel who service equip been in operation from 2 to 14 years and have ment contaminated~by crud can generally be reduced generating capacities ranging from less than 100 substantially by minimizing the formation of crud and MWe to 800 MWe. In view of the anticipated growth by designing or modifying equipment to minimize lo of nuclear power stations over the next few decades cations where crud can deposit and accumulate. Pro visions for isolating components and flusiing with and the radiation exposure experience to date, addi tional efforts to reduce radiation doses to nuclear crud-removing fluid such as demineralized water can power station personnel are warranted. often reduce accumulations prior to activities such as maintenance or equipment replacement.

The wide range in collective radiation doses to sta tion personnel among the various stations appears to Station and equipment layout also can affect the be primarily a function of doses received in mainte potential for radiation exposures. Exposures at sites nance operations in radiation areas. Some data are where multiple radiation sources exist sometimes can be reduced by additional separation of individual available to permit estimates of the distribution of sources. Adequate space for ease of maintenance and

3 The term "radiation protection," as used in this guide, is con other operations can permit the tasks to be completed sidered to be synonymous with the term "applied health more quickly, thereby reducing the length of expo physics"; i.e., the development and implementation of methods and procedures necessary to evaluate radiation hazards and to "4"Crud" is corrosion and erosion products and other solids that provide protection to man and his environment from unwar are formed by chemical and physical reaction between the reac ranted exposure. tor coolant and structural materials.

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sures. Shielding by structural materials, equipment, ing at the judgment, but it should not be the decisive and auxiliary or permanent shields can reduce expo factor in all cases.

sures by isolating radiation sources. Where equip ment components constitute a substantial radiation The nuclear steam supply system (NSSS) vendor, source that cannot be effectively reduced in place, the designer, the architect-engineer (A/E), the con features that permit the removal of such components structor, and the operator of the nuclear power facil for maintenance at remote locations often can be ef ity each have responsibilities related to the effort of fective in reducing exposures. The use of remote maintaining occupational radiation exposures handling features also can reduce exposures of station ALARA. Thus, coordination and cooperation are es personnel in certain instances. sential to achieving these goals and objectives of maintaining occupational radiation exposures Station technical and supervisory personnel, work ALARA.

ing closely with radiation protection personnel, can This guide is written primarily for the applicant or reduce exposures by planning activities of personnel licensee. However, the designer, the A/E, and the who must enter radiation areas, by studying the ac constructor will find many of the guide's consid tions and procedures of individuals working in such erations helpful in the design and construction proc areas, and by conducting postoperation debriefings ess to ensure that their efforts are consistent with the on projects resulting in substantial exposures to iden needs of the applicant or licensee to maintain radia tify how procedures might be modified to reduce ex tion exposures ALARA.

posures on subsequent similar tasks. Training pro grams for all station personnel can establish and rein Specific design or operational objectives for main force the principles of radiation protection as applied taining radiation exposures ALARA are suggested by to specific job functions. By making personnel aware the parameters that determine the magnitude of doses of the methods and the special equipment and protec to station personnel, both as individuals and as a tive equipment available to them, potential radiation group. Doses to personnel in nuclear power stations doses can be reduced. are predominantly from external exposure, i.e., from radiation sources external to the body. However, The concept of maintaining occupational radiation there also exists a potential for doses from internal exposures ALARA does not embody a specific num exposures, i.e., from radioactive materials taken into erical guideline value at the present time. Rather, it is a philosophy that reflects specific objectives for radi the body.

ation dose management in: Important parameters in determining doses from

1. Establishing a program to maintain occupational external exposures are (1) the length of time that the radiation exposures ALARA; receptor remains in the radiation field and (2) the in

2. Designing facilities and selecting equipment; tensity of the radiation fiel

d. Some degree of expo

3. Establishing a radiation control program, plans, sure of station personnel cannot be avoided during and procedures; and the operation and maintenance of nuclear power sta

4. Making supporting equipment, instrumentation, tions. However, there are many ways by which the and facilities available. exposures and resultant doses can be lowered by re ducing the time interval of the exposure and the in When an adequate data base, including economic tensity of the radiation field. The intensity of the information, is available, the criteria for keeping an radiation field is determined by (1) the quantity of nual collective doses to station personnel ALARA radioactive material, (2) the nature (i.e., characteris might be derived or selected in numerical terms. tics) of the emitted radiation, (3) the nature of the However, a data base of operating experience and shielding between the radiation source and the re cost information to provide quantitative guidance for ceptor, and (4) geometry (e.g., distances and establishing such criteria is not available at this time, dimensions).

and the criteria for meeting the provision of para graph 20. 1(c) of 10 CFR Part 20 must therefore take Parameters important in determining doses from the form of qualitative guidance (e.g., goals, objec internal exposures are (1) the quantity of radioactive tives, and statements of good practice). material taken into the body, (2) the nature (isotopi cal and body deposition characteristics) of the material, The NRC staff has not performed a cost-benefit and (3) the time interval over which the material analysis for each of the considerations discussed or is retained by the body. The principal modes by presented in Section C of this guide. This guide pre which radioactive material can be taken into the body sents goals and objectives that were selected to are (1) inhalation, (2) ingestion, (3) skin absorption, satisfy the principles, philosophy, and criteria for and (4) injection through wounds. At nuclear power maintaining occupational radiation exposures stations, radioactive materials are generally confined, ALARA. Attaining these goals and objectives will but some dispersion within the station is unavoidable require good engineering judgment on a case-by-case and constitutes the source of (1) contaminated air and basis. A cost-benefit analysis may be helpful in arriv- liquids that present the potential for intake by inhala-

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tion and absorption and (2) contaminated surfaces Attaining the following objectives to the extent that present the potential for intake by ingestion and practicable throughout the planning, designing, con through cuts or abrasions in the skin. Absorption structing, operating, maintenance, and decommis generally is not an important intake mode at nuclear sioning of an LWR station will be considered to pro power stations except for tritium, which can be ab vide reasonable assurance that exposures of station sorbed through the skin. personnel to radiation will be ALARA. The methods are deliberately stated such that considerable flexibil Consequently, the basic variables that can be con ity can be used in the manner by which the objectives trolled to limit doses from internal exposures are those that limit (1) the amount of contamination, (2) can be achieved. Differences among stations might the dispersal of the contamination, and (3) the length necessitate further innovation in methods used to of time that personnel must spend in contaminated achieve the objectives.

areas. Protective equipment can keep the intake of 1. Program for Maintaining Station Personnel the contaminant to a minimum. Physical and chemi Radiation Doses ALARA

cal methods can be used to hasten the elimination of To attain the integrated effort needed to keep expo radioactive material taken into the body; however, sures of station personnel ALARA, each applicant because of the risks associated with the use of these and licensee should develop an ALARA program that methods, they are reserved for very serious cases reflects the efforts to be taken by the utility, nuclear where the probability of experiencing biological ef steam supply system vendor, and architect-engineer fects is quite substantial, e.g., large intakes such as to maintain radiation exposure ALARA in all phases those that might occur in serious accident situations. of a station's life. This program should be in written Objectives stated in this guide for maintaining occu form and should contain sections that cover the gen pational radiation exposures ALARA are derived by erally applicable guidance presented in this guide, as considering the parameters that affect dose, the vari a minimum, and more specific guidance as required ables that exist in the station design features, and the to address the particular LWR that is the subject of variables that can be provided by station administra the licensing action. This program may be combined tive actions. Section C, Regulatory Position, states with the station's radiation protection manual, safety objectives in a manner that encourages innovation by analysis report, or other documents or submittals. It permitting considerable flexibility on the part of the need not be an independent document.

utility, the NSSS vendor, the designer, the construc a. Establishment of a Program To Maintain Oc tor, and the A/E. However the regulatory position cupational Radiation Doses ALARA

also describes a large number of specific concerns that should be addressed in meeting the goals and ob (1) A management policy for, and commitment jectives. to, ensuring that the exposure of station personnel to radiation will be ALARA should be established.

C. REGULATORY POSITION

(2) The policy and commitment should be re flected in written administrative procedures and in The goals of the effort to maintain occupational structions for operations involving potential expo radiation exposures ALARA are (1) to maintain the sures of personnel to radiation and should be re annual dose to individual station personnel as low as flected in station design features. Instructions to de is reasonably achievable and (2) to keep the annual signers, constructors, vendors, and station personnel integrated (collective) dose to station personnel (i.e., specifying or reviewing station features, systems, or the sum of annual doses (expressed in man-rems) equipment should reflect the goals and objectives to to all station personnel) as low as is reasonably maintain occupational radiation exposures ALARA.

achievable. (Few utilities design or build their nuclear power sta The NRC staff believes that the stated objectives tions; but as customers of designers and builders, are attainable with current technology and with good utilities should expect the designers and builders to operating practices. The costs for attaining these ob be responsive to their needs and instructions.)

jectives have not been established and are expected to b. Organization, Personnel, and Responsibilities vary widely depending on the features of the specific power reactor facility and the method selected to ac (1) In view of the need for upper-level manage complish the objectives. The favorable cost-benefit ment support, responsibility and authority for imple ratio for achieving some of these objectives may be menting the program to maintain occupational radia obvious without a detailed study. For other objec tion exposures ALARA should be assigned to an in tives, however, a cost-benefit study might be re dividual (or committee) with organizational freedom quired to determine whether the objectives are rea to ensure development and implementation. Respon sonably achievable. Doses to station personnel can sibilities and authorities should include:

affect station availability, and this factor should be (a) Ensuring that a corporate program that in considered in assessing the cost-benefit ratio. tegrates management philosophy and regulatory re-

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quirements is established, with specific goals and ob (3) The Radiation Protection Manager (RPM)

jectives for implementation included; (onsite) has a safety function and responsibility to (b) Ensuring that an effective measurement both employees and management that can be best ful system is established and used to determine the de filled if the individual is independent of station divi gree of success achieved by station operations with sions, such as operations, maintenance, or technical regard to the program goals and specific objectives; support, whose prime responsibility is continuity or improvement of station operability. The RPM should (c) Ensuring that the measurement system re have direct recourse to responsible management per sults are reviewed on a periodic basis and that correc sonnel in order to resolve questions related to the tive actions are taken when attainment of the specific conduct of the radiation protection program.

objectives appears to be jeopardized;

(d) Ensuring that the authority for providing (The specific responsibilities given here for procedures and practices by which the specific goals the RPM are illustrative and not intended to be all and objectives will be achieved is delegated; and inclusive with respect to the ALARA program or ef fort. They do not include any of the responsibilities (e) Ensuring that the resources needed to in areas other than ALARA efforts.)

achieve goals and objectives to maintain occupational radiation exposures ALARA are made available, Responsibilities of the RPM with respect to a In view of the responsibilities required to im program to maintain occupational radiation exposures plement a program to maintain occupational radiation ALARA should include:

exposures ALARA, the individual (or committee)

selected for this function might also be chosen to (a) Participating in design reviews for coordinate the effort among the several corporate facilities and equipment that can affect potential radi functional groups (such as the operations, mainte ation exposures;

nance, technical support, engineering, safety, and (b) Identifying locations, operations, and con radiation protection groups) and to represent the cor ditions that have the potential for causing significant porate interests in dealing with the NSSS designer, exposures to radiation;

vendor, A/E, and builder during the design and con struction phases. If the expertise for performing this (c) Initiating and implementing an exposure function is not within the corporation when the sta control program;

tion is in the design stage, consultants who possess (d) Developing plans, procedures, and the required expertise should be used. The utility methods for keeping radiation exposures of station should obtain assurance that available data and ex personnel ALARA;

perience obtained from similar nuclear power stations are considered and reflected in the work of the NSSS (e) Reviewing, commenting on, and recom designer, vendor, A/E, and builder so as to provide mending changes in job procedures to maintain expo features in the new station that permit an effective sures ALARA;

ALARA program. (f) Participating in the development and ap

(2) The Plant Manager (Superintendent or proval of training programs related to work in radia equivalent) is responsible for all aspects of station tion areas or involving radioactive materials;

operation, including the onsite radiation protection (g) Supervising the radiation surveillance pro program. gram to maintain data on exposures of and doses to Responsibilities of the Plant Manager with re station personnel, by specific job functions and type spect to a program to maintain occupational radiation of work;

exposures ALARA should include: (h) Supervising the collection, analysis, and (a) Ensuring support from all station person- evaluation of data and information attained from nel; radiological surveys and monitoring activities;'

(b) Participating in the selection of specific (i) Supervising, training, and qualifying the goals and objectives for the station; radiation protection staff of the station; and (c) Supporting the onsite Radiation Protection (j) Ensuring that adequate radiation protection Manager (RPM) in formulating and implementing a coverage is provided for station personnel during all station program in maintaining occupational radiation working hours.

exposures ALARA; and (d) Expediting the collection and dissemina 5 Data collected during outages can indicate trends of radiation tion of data and information concerning the program buildup in equipment that can permit estimates of probable radi to the corporate management. ation levels to be encountered during subsequent outages.

8.8-5

Qualifications 6 needed for the RPM job, as keep it current. Station personnel whose duties do not well as those needed for other positions in organiza require entering radiation areas or working with tions operating nuclear power stations, are presented radioactive materials should receive sufficient in in Regulatory Guide 1.8, "Personnel Selection and struction in radiation protection and station rules and Training." regulations to understand why they should not enter such areas.

c. Training and Instruction Training programs that have as their goal an in A training program in the fundamentals of radia crease in craft skills provide a broader base of knowl tion protection and in station exposure control proce edgeable station personnel available to service dures should be established. It should include in equipment in radiation areas and permit the services structing all personnel whose duties require (1) work to be performed more reliably and more efficiently.

ing with radioactive materials, (2) entering radiation This can promote lower individual and collective areas, or (3) directing the activities of others who dose levels.

work with radioactive materials or enter radiation d. Review of New or Modified Designs and areas. The training program also should include suf Equipment Selection ficient instruction in the biological effects of expo sures to radiation to permit the individuals receiving (1) Since several groups within a utility (e.g.,

the instruction to understand and evaluate the signifi maintenance, operations, radiation protection, tech cance of radiation doses in terms of the potential nical support, engineering, and safety groups) are in risks. terested in station desigrn and equipment selection, the utility should ensure that these groups are The training should be commensurate with the adequately represented in the review of the design of duties and responsibilities of those receiving the in the facility and the selection of equipment. A coordi structions, as well as with the magnitude of the po nated effort by the several functional groups within tential doses and dose rates that can be anticipated. the utility is required to ensure that station features Personnel (including contractor personnel) who direct will permit the goals and objectives of the ALARA

the activities of others should be familiar with the program to be achieved. Although the A/E and desig licensee's radiation control program and should have ners greatly influence station design features, utilities the authority to implement the licensee's commitment should not delegate all responsibilities for station de to ensure the radiation exposures of station personnel sign review and equipment selection to the NSSS de will be ALARA. signer, vendor, or A/E.

The training program should include instruction (2) Design concepts and station features should on (1) radiation protection rules for the station and reflect consideration of the activities of station per

(2) the applicable Federal regulations. Copies of sonnel (such as maintenance, refueling, inservice in these rules and regulations should be made available spections, processing of radioactive wastes, decon to those receiving the instructions. The training pro tamination, and decommissioning) that might be an gram should be approved by the RPM and presented ticipated and that might lead to personnel exposure to by competent instructors. The information presented substantial sources of radiation. Radiation protection in the training program should be reviewed periodi aspects of decommissioning should be factored into cally and modified, where necessary, to reflect con planning, designing, construction, and modification temporary techniques and adjustments based on ex activities. Station design features should be provided perience in station operations. Instruction of station to reduce the anticipated exposures of station person personnel should stress the importance of exposure nel to these sources of radiation to the extent practic reduction efforts by every individual and should em able.

phasize the need for feedback of information obtained when similar tasks were performed previously. (3) Specifications for equipment should reflect the objectives of the ALARA program, including Station personnel should receive instruction at considerations of reliability, serviceability, limitations periodic intervals to reinforce their knowledge and of internal accumulations of radioactive material, and other features addressed in this guid

e. Specifications

6 Consideration has been given to peer group certification, i.e., for replacement equipment also should reflect mod certification of health physicists by the American Board of ifications based on experience gained from using the Health Physics (ABHP), as representing evidence of adequate original equipment.

qualifications for RPM candidates. While the staff believes that peer group certification is desirable, the present ABHP certifica 2. Facility and Equipment Design Features tion is not necessarily specifically applicable to applied health physics or radiation protection needs in nuclear power stations. Radiation sources within a nuclear power station However, the staff is discussing with the ABHP the prospects differ appreciably with respect to location, intensity, for a special certification program specifically directed toward the needs of radiation protection personnel at nuclear power and characteristics. The magnitude of the dose rates stations. that results from these sources is dependent on many

8.8-6

factors, including the facility and equipment design, areas and control over the movement of sources of layout, mode and length of operation, and radiation radiation within the station. Where high radiation areas (>100 mrem/h) exist, § 20.203 of 10 CFR Part source strength and characteristics.

20 requires that station design features and adminis To provide a basis for design, the quantity and trative controls provide effective ingress control, ease isotopic composition of the radioactive material that of egress, and appropriate warning devices and can be anticipated to be contained, deposited, or ac notices. Access control of radiation areas also should cumulated in the station equipment should be esti reflect the following considerations:

mated. Fission product source terms should be esti (1) Extraordinary design features are warranted mated using these bases: (1) an offgas rate of to avoid any potential dose to personnel that is large

100,000 gCi/sec after 30 minutes delay for BWRs enough to cause acute biological effects and that and (2) 0.25% fuel cladding defects for PWRs. Acti vation source terms, including activated corrosion could be received in a short period of time. Positive products, should be based on measurements and ex control of ingress to such areas, permanent shielding, source removal, or combinations of these alternatives perience gained from operating stations of similar de can reduce the dose potential.

sign. ANSI N237-1976 (Ref. 7) is based on such ex perience and provides information that can be used as (2) Administrative controls such as standard a basis for estimating activation source terms. When operating procedures can be effective in preventing operating measurements are used, extrapolation of inadvertent exposures of personnel and the spread of data to equilibrium conditions may be needed to esti contamination when radioactive material or contami mate ultimate activation source terms. Neutron and nated equipment must be transported from one station prompt gamma source terms should be based on ap location to another and when the route of transport plicable operating experience and reactor core through lower radiation zones or "clean" areas can physics calculations. not be avoided.

ALARA program objectives are presented below (3) Station features such as platforms or walk for each of several station features or functions. Each ways, stairs, or ladders that permit prompt accessibil statement of objective is followed by a number of ity for servicing or inspection of components located specific concerns or suggestions that should be ad in higher radiation zones can reduce exposure of per dressed. sonnel who must perform these services.

a. Access Control of Radiation Areas b. Radiation Shields and Geometry To avoid unnecessary and inadvertent exposures Radiation shields should be designed using the of personnel to radiation, the magnitude of the poten tial dose rates at all locations within the station design basis assumptions explained in regulatory po sition 2 and conservative assumptions for geometries.

should be estimated during station design. Actual dose rates should be measured periodically during Calculational methods known to provide reliable and accurate results (i.e., methods and modeling tech operation to determine current exposure potentials.

Zones associated with the higher dose rates should be niques that have been demonstrated to give accept able accuracy in analyses similar to the problem of kept as small as reasonably achievable consistent concern) should be used to determine appropriate with accessibility for accomplishing the services that shield thicknesses. Shield design features should re must be performed in those zones, including equip ment laydown requirements. Radiation zones where flect the following considerations to maintain occupa tional radiation exposures ALARA:

station personnel spend substantial time should be de signed to the lowest practical dose rates. (1) Exposure of personnel servicing a specific (It is common practice to identify "radiation component (such as a pump, filter, or valve) to radia tion from other components containing radioactive zones" within a nuclear power station. The zone des ignations are established to reflect the design material can be reduced by providing shielding be tween the individual components that constitute sub maximum dose rates that may exist in areas within stantial radiation sources and the receptor.

the station where station personnel must have access to perform required services. Several systems for de (2) Where it is impracticable to provide perma signating "radiation zones" currently exist among nent shielding for individual components that consti the utilities, and ANSI Committee 6.7 is developing tute substantial radiation sources, the exposure of a standard that should prove useful in attaining com personnel maintaining such components can be re mon designations and terminology in this matter. To duced (a) by providing as much distance as practica avoid ambiguity, no reference to radiation zone num ble between the serviceable components and the sub bers is made in this guide at this time.) stantial radiation sources in the area and (b) by pro viding temporary shields around components that A system should be established to permit effec contribute substantially to the dose rate.

tive control over personnel access to the radiation

8.8-7

(3) Potential exposure of station personnel to (10) Floor and equipment drains, piping, and radiation from certain systems containing radiation sumps that are provided to collect and route any con sources can be reduced by means of a station layout taminated liquids that might leak or be spilled from that permits the use of distance and shielding between process equipment or sampling stations can become the sources and work locations. These systems in substantial radiation sources. The drain lines can be clude (but are not limited to) the NSSS and the reac located in concrete floors, concrete ducts, columns, tor water cleanup, offgas treatment, solid waste or radwaste pipe chases to provide shielding. These treatment, and storage systems, as well as systems systems can also become a source of airborne con infrequently containing radiation sources such as the tamination because of the potential for gases to form standby gas treatment and residual heat removal sys in, and be released by, such systems (see regulatory tems. position 2.d(6)).

Radiation from an operating BWR turbine can c. Process Instrumentation and Controls constitute a substantial source of exposure for con struction personnel or others who have access to the Appropriate station layout and design features site for extended periods of time if insufficient shield should be provided to reduce the potential doses to ing is provided. personnel who must operate, service, or inspect sta tion instrumentation and control

s. The following con

(4) Streaming or scattering of radiation from lo siderations should be reflected in selecting the station cally shielded components (such as cubicles) can be features:

reduced by providing labyrinths for access. However, such labyrinths or other design features of the cubicle (1) The exposure of personnel who must manu should permit the components to be removed readily ally operate valves or controls can be reduced from the cubicle for repair or replacement where such through the use of "reach rods" or remotely operated work is expected or anticipated. Single-scatter valves or controls. However, these devices can re labyrinths may be inadequate if the cubicle contains a quire lubrication and maintenance that can be the substantial radiation source. source of additional exposures, and these factors should be taken into consideration.

(5) Streaming of radiation into accessible areas through penetrations for pipes, ducts, and other (2) The exposure of personnel who must view or shield discontinuities can be reduced (a) by means of operate instrumentation, monitors, and controls can layouts that prevent substantial radiation sources be reduced by locating the readouts or control points within the shield from being aligned with the penetra in low radiation zones.

tions or (b) by using "shadow" shields such as (3) Instrumentation must satisfy functional re shields of limited size that attenuate the direct quirements, but the exposure of personnel can be re radiation component. Streaming also can occur duced if the instruments are designed, selected, spec through roofs or floors unless adequate shielding en ified, and located with consideration for long service closes the source from all directions. life, ease and low frequency of maintenance and

(6) The exposure of station personnel to radia calibration, and low crud accumulation. Operating tion from pipes carrying radioactive material can be experience should be recorded, evaluated, and re reduced by means of shielded chases. flected in the selection of replacement instrumenta tion.

(7) Design features that permit the rapid removal and reassembly of shielding, insulation, and other (4) The use of instrumentation that contains min material from equipment that must be inspected or imal quantities of contaminated working fluid (e.g.,

serviced periodically can reduce the exposure of sta pressure transducers rather than bellows-type pres tion personnel performing these activities. sure gauges) can reduce the potential for exposure at the readout locations.

(8) Space within cubicles and other shielding to provide laydown 'space for special tools and ease of d. Control of Airborne Contaminants and Gase servicing activities can reduce potential doses by ous Radiation Sources permitting the services to be accomplished expediti ously, thus reducing exposure time. Station design features should be provided in all station work areas to limit the average concentrations

(9) The exposure of personnel who service com of radioactive material in air to levels well below the ponents that constitute substantial radiation sources values listed in Appendix B, Table 1, Column 1 of 10

or are located in high radiation fields can be CFR Part 20. Effective design features can minimize minimized by removing the components and trans the occurrence of occasional increases in air contami porting them to low radiation zones where shielding nation and the concentrations and a-mounts of contam and special tools are available. Design features that inants associated with any such occasional increases.

permit the prompt removal and installation of these Designs that permit repeated, identified releases of components can reduce the exposure time. large amounts of radioactive materials into the air

8.8-8

spaces occupied by personnel are contrary to a pro trunks"' without imbalancing the ventilation system.

gram to maintain occupational radiation exposures In areas where contarninated equipment must be ALARA. opened infrequently, portable auxiliary ventilation systems featuring blowers, HEPA filters, and acti Station design features should provide for pro vated charcoal filters (where radioiodine might be an tection against airborne radioactive material by ticipated) on carts can be used effectively. Portable means of engineering controls such as process, con auxiliary ventilation systems should be tested fre tainment, and ventilation equipment. The routine quently to verify the efficiency of the filter elements provision of respiratory protection by use of indi in their mountings. When the efficiency has been ver vidually worn respirators rather than engineered de ified, the system may be exhausted to the room or the sign features is generally unacceptable. The use of ventilation exhaust duct without further treatment and respirators, however, might be appropriate in certain thus imbalance of the permanent ventilation system nonroutine or emergency operations when the appli can be avoided.

cation of engineering controls is not feasible or while such controls are being installed. (4) Machining of contaminated surfaces (e.g.,

welding, grinding, sanding, or scaling) or "plug The approved use of respirators is subject to the ging" of leaking steam generator or condenser tubes requirements of § 20.103, "Exposure of Individuals can be substantial sources of airborne contamination.

to Concentrations of Radioactive Materials in Air in These sources can be controlled by using auxiliary Restricted Areas," of 10 CFR Part 20 and to regula ventilation systems.

tory guidance on acceptable use. (See Regulatory Guide 8.15, "Acceptable Programs for Respiratory (5) Sampling stations for primary coolant or Protection," and NUREG-0041, "Manual of Res other fluids containing high levels of radioactive ma piratory Protection Against Airborne Radioactive Ma terial can constitute substantial sources of airborne terials" (Ref. 8).) Design features of the station venti contamination. Such sources can be controlled by lation system and gaseous radwaste processing sys using auxiliary ventilation systems.

tems should reflect the following considerations: (6) Wet transfer or storage of potentially con

(1) The spread of airborne contamination within taminated components will minimize air contamina the station can be limited by maintaining air pressure tion. This can be accomplished by keeping contami gradients and airflows from areas of low potential nated surfaces wet, by spraying, or, preferably, by keeping such surfaces under water.

airborne contamination to areas of higher potential contamination. Periodic checks would ensure that the design pressure differentials are being maintained.

e. Crud Control

(2) Effectively designed ventilation systems and Design features of the primary coolant system, gaseous radwaste treatment systems will contain the selection of construction materials that will be in radioactive material that has been deposited, col contact with the primary coolant, and features of lected, stored, or transported within or by the sys equipment that treat primary coolant should reflect tems. Exposures of station personnel to radiation and considerations that will reduce the production and ac to contamination from ventilation or gaseous rad cumulation of crud in stations where it can cause high waste treatment components occur as a result of the exposure levels. The following items should be con need to service, test, inspect, decontaminate, and re, sidered in the crud control effort:

place components of the systems or perform other (1) Production of Co-58 and Co-60, which con duties near these systems. Potential doses from these stitute substantial radiation sources in crud, can be systems can be minimized by providing ready access reduced by specifying, to the extent practicable, low to the systems, by providing space to permit the ac nickel and low-cobalt bearing materials for primary tivities to be accomplished expeditiously, by separat coolant pipe, tubing, vessel internal surfaces, heat ex ing filter banks and components to reduce exposures changers, wear materials, and other components that to radiation from adjacent banks and components, are in contact with primary coolant. Alternative mate and by providing sufficient space to accomodate aux rials for hard facings of wear materials of high-cobalt iliary ventilation or shielding of components.

content should be considered where it is shown that

(3) Auxiliary ventilation systems that augment these high-cobalt materials contribute to the overall ex the permanent system can provide local control of posure levels. Such consideration should also take into airborne contaminants when equipment containing account potential increased service/repair require potential airborne sources is opened to the atmos ments and overall reliability of the new material in phere. Two types of auxiliary ventilation systems relation to the old. Alternative materials for high have proved to be effective. In areas where contami nickel alloy materials (e.g., Inconel 600) should be nated equipment must be opened frequently, dampers considered where it is shown that these materials con and fittings can be provided in ventilation ducts to tribute to overall exposure levels. Such consideration permit the attachment of flexible tubing or "elephant should also take into account potential increased

8.8-9

service/repair requirements and overall reliability of limit the spread of contamination from leakage of the new materials in relation to the old. liquid systems.

(2) Loss of material by erosion of load-bearing (3) Accumulations of crud or other radioactive hard facings can be reduced by using favorable material that cannot be avoided within components or geometrics and lubricants, where practicable, and by systems can be reduced by providing features that using controlled leakage purge across journal sleeves will permit the recirculation or flushing of fluids with to avoid entry of particles into the primary coolant. the capacity to remove the radioactive material through chemical or physical actio

n. The fluids con

(3) Loss of material by corrosion can be reduced taining the contaminants will require treatment, and by continuously monitoring and adjusting oxygen this source should be considered in sizing station concentration and pH in primary coolant above radwaste treatment systems.

250°F and by using bright hydrogen-annealed tubing and piping in the primary coolant and feedwater sys (4) Continuity in the functioning of processing tems. or ventilation systems that are important for control

(4) Consideration should be given to cleanup ling potential doses to station personnel can be pro systems (e.g., using graphite or magnetic filters) for vided during servicing of the systems if redundant removal of crud from the primary coolant during op components or systems are available so that the com eration. ponent (with associated piping) being serviced can be isolated.

(5) Deposition of crud within the primary cool ant system can be reduced by providing laminar flow (5) The potential for contamination of "clean and smooth surfaces for coolant and by minimizing services" (such as station service air, nitrogen, or crud traps in the system to the extent practicable. water supply) from leakage from adjacent systems containing contaminants can be reduced by separating f. Isolation and Decontamination piping for these services from piping that contains radioactive sources. Piping that carries radioactive Potential doses to station personnel who must sources can be designed for the lifetime of the sta service equipment containing radioactive sources can tion, thus avoiding the necessity for replacement (and be reduced by removing such sources from the attendant exposures) and lessening the potential for equipment (decontamination), to the extent practica contamination of clean services if it is impracticable ble, prior to servicing. Serviceable systems and com to provide isolation through separate chases.

ponents that constitute a substantial radiation source should be designed, to the extent practicable, with (6) Surfaces can be decontaminated more ex features that permit isolation and decontamination. peditiously if they are smooth, nonporous, and free Station design features should consider, to the extent of cracks, crevices, and sharp corners. These desira practicable, the ultimate decommissioning of the ble features can be realized by specifying appropriate facility and the following concerns: design instructions, by giving attention to finishing work during construction or manufacture, and by

(1) The necessity for decontamination can be re using sealers (such as special paints) on surfaces duced by limiting, to the extent practicable, the de where contamination can be anticipated. (ANSI

position of radioactive material within the processing NIO.2 provides helpful guidance on this matter equipment-particularly in the "dead spaces" or (Ref. 9).)

"traps" in components where substantial accumula tions can occur. The deposition of radioactive mate (7) Where successful decontamination of impor rial in piping can be reduced and decontamination ef tant systems could be prevented by an anticipated forts enhanced by avoiding stagnant legs, by locating failure of a critical component or feature, additional connections above the pipe centerline, by using slop features that permit alternative decontamination ac ing rather than horizontal runs, and by providing tions can be provided.

drains at low points in the system.

(2) The need to decontaminate equipment and (8) Contaminated water and deposited residues station areas can be reduced by taking measures that in spent fuel storage pools contribute to the exposure will reduce the probability of release, reduce the at accessible locations in the area. Treatment systems amount released, and reduce the spread of the con that remove contaminants from the water can perform taminant from the source (e.g., from systems or more efficiently (a) if intake and discharge points for the treatment systems are located to provide enhanced components that must be opened for service or re placement). Such measures can include auxiliary ven mixing and to avoid stagnation areas in the pool and tilation systems (see regulatory position 4.b), treat (b) if pool water overflows and skimmer tanks are ment of the exhaust from vents and overflows (see provided. Fluid jet or vacuum-cleaner-type agitators regulatory position 2.h(8)), drainage control such as can help reduce the settling of crud on surfaces of the curbing and floors sloping to local drains, or sumps to pool system.

8.8-10

g. Radiation Monitoring Systems (a) Using full-ported valves constructed such that the slurry will not interfere with the opening or Central or "built-in" monitoring systems that closing of the valve and give information on the dose rate and concentration of airborne radioactive material in selected station (b) Avoiding cavities in valves.

areas can reduce the exposure of station personnel

(3) The deposition of resin and sludge that would who would be required to enter the areas to obtain the occur if elbow fittings were used can be reduced by data if such systems were not provided. These sys using pipe bends of at least five pipe diameters in tems also can provide timely information regarding changes in the dose rate or concentrations of airborne radius. Where pipe bends cannot be used, long radius radioactive material in the areas. (The installation of elbows are preferred.

a central monitoring system is easier and less expen (4) Smoother interior pipe surfaces at connec sive if it is a part of the original station design.) The tions (with attendant reductions in friction losses, de selection or design and installation of a central position of material, and tendencies to "plug") can monitoring system should include consideration of be achieved by using butt welds rather than socket the following desirable features: welds and by using consumable inserts rather than backing rings.

(1) Readout capability at the main radiation pro tection access control point; (5) Where the use of tees cannot be avoided, line

(2) Placement of detectors for optimum coverage losses can be reduced if the flow is through the run (straight section) of the tee, and accumulations of ma of areas (Ref. 10);

terial in the branch of the tee can be reduced by

(3) Circuitry that indicates componemt failure; orienting the branch horizontally or (preferably)

above the run.

(4) Local alarm and readout;

(6) Slurry piping is subject to plugging that may

(5) Clear and unambiguous readout; require backflushing from the tank and equipment iso

(6) Ranges adequate to ensure readout of the lation valves and pressurizing with water, nitrogen, or highest anticipated radiation levels and to ensure air to "blow out" plugged lines. However, the use of positive readout at the lowest anticipated levels; and pressurized gas for blowing out lines can present a po tential contamination source and may not be effective

(7) Capability to record the readout of all sys in relieving plugged lines.

tems.

(7) Water, air, or nitrogen for sparging can be used to fluidize resins or sludges in storage tanks, The h. Resin and Sludge Treatment Systems use of gases, however, presents a potential source of Systems used to transport, store, or process re airborne contamination and tank rupture from over sins or slurries of filter sludge present a special pressures.

hazard because of the concentrated nature of the (8) The spread of contamination by the loss of radioactive material. Design features for resin- and resin or sludge through overflows and vents can be re sludge-handling systems should reflect this concern duced by using screens, filters, or other features that and the following specific considerations: will collect and retain solids. However, such features

(1) The accumulation of radioactive material in generally require cleaning by remote flushing, by rapid components of systems used to process resin and "replacement, or by other means to reduce exposures sludges can be reduced by: during servicing.

(a) Reducing the length of piping runs; Consideration should be given to ANS N197,

"Design and Performance of BWR Liquid Radioactive (b) Using larger diameter piping (to minimize Waste Processing Systems (N18)" (Ref. 11); ANS

plugging); 55.1, "Design Criteria for the Solid Radwaste Proc (c) Reducing the number of pipe fittings; essing System of BWR, PWR, and HTGR" (Ref. 12);

and ANS N199, "PWR Liquid Waste System Design (d) Avoiding low points and dead legs in pip (N18)" (Ref. 13). These standards cover some as ing; pects of slurry systems.

(e) Using.gravitational flow to the extent prac ticable; and i. Other Features (f) Minimizing flow restrictions of processed Station layout and station tasks should be re material. viewed to identify and provide special features that

(2) The need for maintenance and the presence complement the ALARA program. Station design of intense local radiation sources can be reduced by: should reflect consideration of the following concerns:

8.8-11

(I) The selection of radiation-damage-resistant (9) The sources of radiation such as sedimentation materials for use in high radiation areas can reduce the that occurs in tanks used to process liquids containing need for frequent replacement and can reduce the radioactive material and residual liquids can be re probability of contamination from leakage. duced when servicing by draining the tanks, The de

(2) The use of stainless steel for constructing or sign can include sloping the tank bottoms toward out lining components, where it is compatible with the lets leading to other reprocessing equipment and, process, can reduce corrosion and can provide options where practicable, providing built-in spray or surge for decontamination methods. features.

(3) Field-run piping that carries radioactive mate (10) Spare connections on tanks or other compo rial can cause unnecessary exposures unless due con nents located in higher radiation zones may be desira sideration is given to the routing. Such unnecessary ble to provide flexibility in operations. Exposures of exposures can be avoided if the routing is accom personnel can be avoided if these connections are pro I plished under the cognizance of an individual familiar vided as a part of the original equipment rather than by with the principles of radiation protection or if a de subsequent modification of the equipment in the pres tailed piping layout is provided, i.e., if the piping is ence of radiation.

not field-run. (11) Inspections to satisfy the ASME Code (Ref.

(4) Where filters or other serviceable compo 14) and regulatory requirements can result in expo nents can constitute substantial radiation sources, ex sures of station personnel to radiation. Many of the posures can be reduced by providing features that objectives presented above will aid in reducing poten permit operators to avoid the direct radiation beam tial exposures to personnel who perform the required and that provide remote removal, installation, or ser inspections. Station features and design should, to the vicing. Standardization of filters should be consid extent practicable, permit inspections to be accom ered. plished expeditiously and with minimal exposure of personnel. The effort to maintain occupational radia

(5) The servicing of valves can be a substantial tion exposures ALARA can also be aided by prompt

-source of doses to station personnel. These doses can accessibility, shielding and insulation that can be be reduced by providing adequate working space for quickly removed and reinstalled, and special tools and easy accessibility and by locating the valves in areas instruments that reduce exposure time or permit re that are not in high radiation fields. mote inspection of components or equipment contain ing potential radiation sources.

(6) Leakage of contaminated coolant from the primary system can be reduced by using live-loaded (12) Components can be removed from process valve packings and bellow seals. ing systems more expeditiously if adequate space is provided in the layout of the system and if the inter

(7) Potential doses from servicing valves and connections permit prompt.disconnects.

from leakage can be reduced by specifying and instal (13) Station features that provide a favorable ling reliable valves for the required service, by using working environment such as adequate lighting, venti radiation-damage-resistant seals and gaskets, and by lation, working space, and accessibility (via such using valve back seats. The use of straight-through means as working platforms, cat walks, and fixed lad valve configurations can avoid the buildup of accumu ders) can promote work efficiency.

lations in internal crevices and the discontinuities that exist in valves of other configurations. In most cases, (14) The exposure of station personnel who must valves can be installed in the "stem-up" orientation replace lamps in high radiation areas can be reduced to facilitate maintenance and to minimize crud traps. by using extended service lamps and by providing de The desired features are reliability, -good perform sign features that permit the servicing of the lamps ance, and the ability to be maintained infrequently from lower radiation areas.

and rapidly. (15) An adequate emergency lighting system can

(8) Leaks from pumps can be reduced by using can reduce potential exposures of station personnel by ned pumps where they are compatible with the service permitting prompt egress from high radiation areas if needs, provided that lower personnel exposures can be the station lighting system fails.

achieved thereby. If mechanical seals are used on a pump in a slurry service, features that permit the use 3. Radiation Protection Program of flush water to clean pump seals can reduce the ac A substantial portion of the radiation dose to station cumulation of radioactive material in the seals. Drains personnel is received while they are performing serv on pump housings can reduce the radiation field from ices such as maintenance, refueling, and inspection in this source during servicing. Provision for the collec high radiation areas, The objectives that were pre tion of such leakage or disposal to a drain sump is sented in regulatory position 2 can provide station de appropriate. sign features conducive to an effective program to

8,8-12

maintain occupational radiation exposures ALARA. needed to perform the required services in the radia However, an effective program also requires station tion areas. Such a program would address conditions operational considerations in terms of procedures, job that require a special work permit or other special pro planning, recordkeeping, special equipment, operating cedures.

philosophy, and other support. This section deals with the manner in which the station administrative efforts (8) A work permit form with an appropriate for can influence the variables of (1) the number of per mat can be useful for recording pertinent information sons who must enter high radiation areas or contami concerning tasks to be performed in high radiation nated areas, (2) the period of time the persons must areas so that the information is amenable to cross remain in these areas, and (3) the magnitude of the referencing and statistical analysis. Information of potential dose. interest would include the following items:

a. Preparation and Planning (a) Designation of services to be performed on specific components, equipment, or systems;

Before entering radiation areas where significant doses could be received, station personnel should have (b) Number and identification of personnel the benefit of preparations and plans that can ensure working on the tasks;

the exposures are ALARA while the personnel are per forming the services. Preparations and plans should re (c) Anticipated radiation, airborne radioactive flect the following considerations: material, and contamination levels, based on current surveys of the work areas, and date of survey;

(1) A staff member who is a specialist in radiation protection can be assigned the responsibility for con (d) Monitoring requirements such as continuous tributing to and coordinating ALARA efforts in sup air monitoring or sampling equipment;

port of operations that could result in substantial indi (e) Estimated exposure time required to com vidual and collective dose levels. plete the tasks and the estimated doses anticipated

(2) To provide the bases for planning the activity, from the exposure;

surveys can be performed to ascertain information with (f) Special instructions and equipment to respect to radiation, contamination, airborne radioac minimize the exposures of personnel to radiation and tive material, and mechanical difficulties that might be contamination;

encountered while performing services. (g) Protective clothing and equipment require

(3) Radiation surveys provided in conjunction ments;

with inspections or other activities can define the na ture of the radiation fields and identify favorable loca (h) Personnel dosimetry requirements;

tions where personnel may take advantage of available (i) Authorization to perform the tasks; and shielding, . distance, geometry, and other factors that affect the magnitude of the dose rate or the portions of (j) Actual exposure time, doses, and other in the body exposed to the radiation. formation obtained during the operation.

(4) Photographs of "as installed" equipment or (9) Consideration of potential accident situations components can be valuable for planning purposes and or unusual occurrences (such as gross contamination can be augmented by additional photos taken during leakage, pressure surges, fires, cuts, punctures, or the surveys. The use of portable TV cameras with tap wounds) and contingency planning can reduce the po ing features has considerable merit as both an opera tential for such occurrences and enhance the capability tional aid and a teaching aid. for coping with the situations expeditiously if they oc cur.

(5) The existing radiation levels frequently can be reduced by draining, flushing, or other decontamina (10) Portable or temporary shielding can reduce tion methods or by removing and transporting the dose rate levels near "hot spots" and in the general component to a lower radiation zone. An estimate of area where the work is to be performed.

the potential doses to station personnel expected to re sult from these procedures is germane in selecting (1I) Portable or temporary ventilation systems or among alternative actions. contamination enclosures and expendable floor cover

(6) A preoperational briefing for personnel who ings can control the spread of contamination and limit will perform services in a high radiation area can en the intake by workers through inhalation.

sure that service personnel understand the tasks about to be performed, the information to be disseminated, (12) "Dry runs" on mockup equipment can be useful for training personnel, identifying problems that and the special instructions to be presented.

can be encountered in the actual task situation, and

(7) A program can be implemented to provide ac selecting and qualifying special tools and procedures cess control and to limit exposures to those persons to reduce potential exposures of station personnel.

8.8-13

'(13) Adequate auxiliary lighting and a comforta ble environment (e.g., vortex tube coolers for supplied c. Postoperatlons air suits) can increase the efficiency of the work and Observations, experience, and data obtained dur thus reduce the time spent in the higher radiation ing nonroutine operations in high radiation zones zones. should be ascertained, recorded, and analyzed to iden tify deficiencies in the program and to provide the

(14) Radiation monitoring instruments selected bases for revising procedures, modifying features, or and made available in adequate quantities can permit making other adjustments that may reduce exposures accurate measurements and rapid evaluations of the during subsequent similar operations.

radiation and contamination levels and changes in levels when they occur. Routine calibration of instru (1) Formal or informal postoperation debriefings ments with appropriate sources and testing can ensure of station personnel performing the services can pro operability and accuracy of measurements. vide valuable information concerning shortcomings in preoperational briefings, planning, procedures, special

(15) Performing work on some components inside tools, and other factors that contributed to the cause of disposable tents or, for less complicated jobs, inside doses received during the operation.

commercially available disposable clear plastic glove bags can limit the spread of contamination. Such (2) Dose data obtained during or subsequent to an measures can also avoid unnecessary doses resulting operation can be recorded in a preselected manner as from the need to decontaminate areas to permit per part of a "Radiation Work Permit" or similar program sonnel access or to allow for entry with less restrictive [see regulatory position 3.a(8)] so that the data are protective clothing and equipment requirements. amenable to statistical analyses.

(16) Careful scheduling of inspections and other (3) Information concerning the cause of compo tasks in high radiation areas can reduce exposures by nent failures that resulted in the need for servicing in permitting decay of radiation sources during the reac high radiation areas can provide a basis for revising tor shutdown period and by eliminating some repeti specifications on replacement equipment or for other tive surveys. Data from surveys and experience at modifications that can improve the component reliabil tained in previous operations and current survey data ity. Such improvements can reduce the frequency of can be factored into the scheduling of specific tasks. servicing and thus reduce attendant exposures.

(4) Information gained in operations can provide b. Operations a basis for modifying equipment selection and design During operations in radiation areas, adequate features of new facilities.

supervision and radiation protection surveillance

(5) Summaries of doses received by each category should be provided to ensure that the appropriate pro of maintenance activity can be reviewed periodically cedures are followed, that planned precautions are ob by upper management to compare the incremental re served, and that all potential radiation hazards that duction of doses with the cost of station modifications might develop or that might be recognized during the that could be made.

operation are addressed in a timely and appropriate manner. 4. Radiation Protection Facilities, Instrumentation,

(1) Assigning a health physics (i.e., radiation and Equipment safety or radiation protection) technician the responsi A radiation protection staff with facilities, in bility for providing radiation protection surveillance strumentation, and protective equipment adequate to for each shift operating crew can help ensure adequate permit the staff to function efficiently is an important radiation protection surveillance. element in achieving an effective program to maintain

(2) Personnel monitoring equipment such as occupational radiation exposures ALARA. The selec direct-reading dosimeters, alarming dosimeters, and tion of instrumentation and other equipment and the personal dose rate meters can be used to provide early quantities of such equipment provided for normal sta evaluation of doses to individuals and the assignment tion operations should be adequate to meet the antici of those doses to specific operations (see Regulatory pated needs of the station during normal operations Guides 1.16, "Reporting of Operating Informa and during major outages that may require supplemen tion-Appendix A Technical Specifications," and tal workers and extensive work in high radiation areas.

8.4, "Direct-Reading and Indirect-Reading Pocket (Accident situations are not considered in this guide.)

Station design features and provisions should reflect the Dosimeters ").

following considerations:

(3) Communication systems between personnel in high radiation zones and personnel who are monitoring a. Counting Room the operation in other locations can permit timely ex A low-radiation background counting room is changes of information and avoid unnecessary expo needed to perform routine analyses on station samples sures to monitoring personnel. containing radioactive material collected from air, wa-

8.8-14

ter, surfaces, and other sources. An adequately (6) Portal monitors.

equipped counting room would include:

d. Protective Equipment

(1) Multichannel gamma pulse height analyzer (Regulatory Guide 5.9, "Specifications for Ge(Li) Utility-supplied protective equipment selection Spectroscopy Systems for Material Protection should include consideration of :

Measurements-Part 1: Data Acquisition Systems," (1) Anticontamination clothing and equipment provides guidance for selecting Ge(Li) spectroscopy that meet the requirements of ANSI Z-88.2 (Ref. 15)

systems); for use in atmospheres containing radioactive mate

(2) Low-background alpha-beta radiation propor rials or the National Institute of Occupational Safety tional counter(s) or scintillation counter(s); and Health's (NIOSH) "Certified Personal Protective Equipment List," and current supplements from

(3) End-window Geiger-Muller (G-M) counter(s); DHEW/PHS (Ref. 16).

and

(2) Respiratory protective equipment, including

(4) A liquid scintillation counter for tritium a respirator fitting program that satisfies the guidance analyses. Analyses of bioassay and environmental of Regulatory Guide 8.15 and NUREG-0041 (Ref. 8).

samples and whole-body counting (see Regulatory Guide 8.9, "Acceptable Concepts, Models, Equa e. Support Facilities tions, and Assumptions for a Bioassay Program") call Design features of radiation protection support for additional equipment and laboratory space if the facilities should include consideration of:

analyses are performed by station personnel rather than by other specialists through contractual arrangements. (1) A portable-instrument calibration area de signed and located such that radiation in the calibra b. Portable Instruments tion area will not interfere with low-level monitoring Portable instruments needed for measuring dose or counting systems;

rates and radiation characteristics would include: (2) Personnel decontamination area (this facility

(1) Low-range (nominally 0 to 5 R per hour) ion should be located and designed to expedite rapid chambers or G-M rate meters; cleanup of personnel and should not be used as a multiple-purpose area or share ventilation with

(2) High-range

7

(0. 1 to at least 500 R per hour) ion food-handling areas) with showers, basins, and in chambers; stalled "frisker" equipment;

(3) Alpha scintillation or proportional count rate (3) Facilities and equipment to clean, repair, and meters; decontaminate personnel protective equipment,

(4) Neutron dose equivalent rate meters; monitoring instruments, hand tools, electromechani cal parts, or other material (highly contaminated tools

(5) Air samplers for short-term use with particu or other equipment should not be decontaminated in late filters and iodine collection devices (such as acti the area used to clean respiratory equipment);

vated charcoal cartridges); and

(4) Change rooms that (preferably) connect with

(6) Air monitors with continuous readout fea the personnel decontamination area and a control sta tures. 7 tion area equipped with sufficient lockers to accom c. Personnel Monitoring Instrumentation modate permanent and contract maintenance workers who may be required during major outages;

Personnel monitoring instrumentation selection should include consideration of: (5) Control stations for entrance or exit of per sonnel into radiation- and contamination-controlled

(1) G-M 'Friskers" for detecting low levels of access areas of the station such as the personnel en radioactive material; trance to the containment buildings and the main en

(2) Direct-reading low-range (0 to 200 mR) and trance to the radwaste processing areas; these control intermediate-range (0 to 1000 mR) pocket dosimet stations also may be used as the control point for ers (see Regulatory Guide 8.4); radioactive material movements throughout the sta tion and for the storage of portable radiation survey

(3) Alarm dosimeters; equipment, signs, ropes, and respiratory protective

(4) Film badges and/or thermoluminescent equipment;

dosimeters (TLD); (6) Equipment to facilitate communication be

(5) Hand and foot monitors; and tween all areas throughout the station; and Variable alarm setpoint features on these instruments can be

(7) Sufficient office space to accommodate the valuable in providing a warning when unexpected substantial temporary and permanent radiation protection staff, changes in dose rate or air concentration occur. permanent records, and technical literature.

8.8-15

I -

D. IMPLEMENTATION

protection design presented in the applicant's final safety analysis report will be reviewed against regula The purpose of this section is to provide informa tory position 2 of this guide and differences from the tion to applicants and licensees regarding the NRC recommendations of the guide will be identified (par staff's plans for using this regulatory guide.

ticularly for plants designed before Regulatory Guide This guide reflects current NRC staff practice in 8.8 was issued). However, no substantive design license application reviews. Therefore, except in changes will be required at the operating license stage those cases in which the applicant proposes an ac unless the design change can prevent substantial ceptable alternative method for complying with speci man-rem exposures that cannot be prevented by pro fied portions of the Commission's regulations, the cedural measures and the design change is consistent methods described herein are being and will continue with the cost-effectiveness principle of maintaining to be used in the evaluation of submittals for con occupational radiation exposures ALARA.

struction permits and operating license applications Methods other than those set forth in this guide until this guide is revised as a result of suggestions may be substituted for those stated herein, provided from the public or additional staff review.

they satisfy the criterion "as low as is reasonably At the operating license review stage, the radiation achievable" of paragraph 20. 1(c) of 10 CFR Part 20.

REFERENCES

1. Ad Hoc Committee of the National Council on 9. ANSI N101.2, "Protective Coatings (Paints) for Radiation Protection and Measurements, "Somatic Light Water Nuclear Reactor Containment Radiation Dose for the General Population," Science Facilities." Copies may be obtained from the Ameri

131, 482 (1960). can National Standards Institute, 1430 Broadway, New York, N.Y. 10018.

2. "The Effects on Populations of Exposure to 10. ANS/HPS 56.8, "Location and Design Criteria Low Levels of Ionizing Radiation,'" National for Area Radiation Monitoring Systems for LWRs,"

Academy of Sciences/National Research Council, (draft).

DHEW Contract PH-43-64-44, November 1972. 11. ANS N197, "Design and Performance of BWR

3. International Commission on Radiological Pro Liquid Radioactive Waste Processing Systems tection (ICRP), "Implications of Commission Rec (N 18)." Copies may be obtained from the American ommendations That Doses Be Kept As Low As Read Nuclear Society, 555 North Kensington Avenue, La ily Achievable," ICRP Publication 22, Pergamon Grange Park, Illinois 60525.

Press, 1973. Copies may be obtained from Pergamon 12. ANS 55.1, "Design Criteria for the Solid Press, Maxwell House, Fairview Park, Elmsford, Radwaste Processing System of BWR, PWR, and New York 10523. HTGR." Copies may be obtained from the American Nuclear Society, 555 North Kensington Avenue, La

4. C. A. Pelletier et al., "Compilation and Analy Grange Park, Illinois 60525.

sis of Data on Occupational Radiation Exposure Ex 13. ANS N199, "PWR Liquid Waste System De perienced at Operating Nuclear Power Plants," sign (N18)." Copies may be obtained from the Atomic Industrial Forum, 1974. American Nuclear Society, 555 North Kensington

5. T. D. Murphy, N. J. Dayem, J. Stewart Bland, Avenue, La Grange Park, Illinois 60525.

and W. J. Pasciak, "Occupational Radiation Expo 14.Section XI, ASME Boiler and Pressure Vessel sure at Light-Water-Cooled Power Reactors, 1969 Code and Addenda. Copies may be obtained from the

1975," NUREG-0109, U.S. Nuclear Regulatory American Society of Mechanical Engineers, United Commission, August 1976. Copies may be obtained Engineering Center, 345 East 47th Street, New York, from the National Technical Information Service, N.Y. 10017.

Springfield, Va. 22161. 15. ANSI Z-88.2, "Practices for Respiratory Pro tection." Copies may be obtained from the American

6. NUREG-0322, "Ninth Annual Occupational National Standards Institute, 1430 Broadway, New Radiation Exposure Report, 1976." Copies may be York, N.Y. 10018.

obtained from the National Technical Information

16. NIOSH, "Certified Personal Protective Service, Springfield, Va. 22161.

Equipment List," July 1974, and supplements by

7. ANSI N237, "Source Term Specification." DHEW/PHS. Published by U.S. Department of Copies may be obtained from the American Nuclear Health, Education, and Welfare, Public Health Serv Society, 555 North Kensington Avenue, La Grange ice, Center of Disease Control, National Institute of Park, Illinois 60525. Occupational Safety and Healt

h. Copies are available

8. Copies of NUREG-0041 may be obtained from from the Office of Technical Publications, National the National Technical Information Service, Institute of Occupational Safety and Health, Post Of Springfield, Va. 22161. fice Building, Cincinnati, Ohio 45202.

9 R_16