Shielding Design

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systems, and provide adequate space for health physics activities. Primary

radiation protection should be provided through the use of engineered controls

(e.g., confinement, ventilation, remote handling, equipment layout, and

shielding). Additional protection for workers should be provided through an

effective radiation protection program that includes implementation of ALARA

concepts.

Additional considerations for specific facility types are included in this handbook;

see Section 2, Special Facilities and Activities.

Shielding Design . The shielding design basis should minimize exposure of an

1.3.2

individual worker to ALARA levels. 10 CFR 835.1002 provides requirements in

this area. In addition, appropriate shielding should be installed, if necessary, to

minimize nonpenetrating external radiation exposures to the skin and lens of the

eye of the worker. In most cases, the confinement barrier or process equipment

provides this shielding. Shielding and other radiation protection measures

should be provided for areas requiring intermittent access (e.g., to perform

preventive maintenance, change components, and adjust systems and

equipment). Straight-line penetration of shield walls should be avoided to

prevent radiation streaming. American National Standard (ANS) 6.4, Guidelines

on the Nuclear Analysis and Design of Concrete Radiation Shielding for Nuclear

Power Plants, provides guidance regarding the design of concrete radiation

shielding. ANS 6.4.2, Specification for Radiation Shielding Materials, provides

guidance regarding material specifications, where it provides a critical

confinement or structural function. American Concrete Institute (ACI) 318M,

Building Code Requirements for Reinforced Concrete, provides general

guidance for the structural design of concrete shielding. Straight-line

penetration of shield walls should be avoided to prevent radiation streaming.

Use of remote, shielded operations (i.e., through the use of handling equipment

such as remote manipulators and lead glass windows) should be considered

when exposures to extremities are anticipated to approach dose limits or where

contaminated puncture wounds could occur.

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