DHS 157.03(120)(120) “Emergency” means an event requiring prompt action to mitigate a threat to the health and safety of workers and the public or a threat of damage to the environment.

DHS 157.03(121)(121) “Energy compensation source” or “ECS” means a small sealed source, with an activity not exceeding 3.7 MBq (100 microcuries), used within a well logging tool, or other tool components, to provide a reference standard to maintain the well logging tool’s calibration when in use.

DHS 157.03(122)(122) “Enriched uranium” means uranium containing more uranium-235 than the naturally occurring distribution of uranium isotopes.

DHS 157.03(123)(123) “Entrance air kerma rate” means the air kerma free in air per unit time at the point where the center of the useful beam enters the patient.

DHS 157.03(124)(124) “Entrance or access point” means any location through which an individual could gain access to radiation areas or to licensed or registered radioactive materials. This includes entry or exit portals of sufficient size to permit human entry, irrespective of their intended use.

DHS 157.03(124g)(124g) “Escorted access” means the continuous direct visual surveillance by an approved individual over an individual in the security zone who is not approved for unescorted access.

DHS 157.03(124m)(124m) “Exclusive use” means the sole use by a single consignor of a conveyance for which all initial, intermediate, and final loading and unloading are carried out in accordance with the direction of the consignor or consignee. The consignor and the carrier must ensure that any loading or unloading is performed by personnel having radiological training and resources appropriate for the safe handling of the consignment. The consignor shall issue specific instructions, in writing, for maintenance of exclusive use shipment controls, and include them with the shipping paper information provided to the carrier by the consignor.

DHS 157.03(125)(125) “Explosive material” means any chemical compound, mixture or device that produces a substantial instantaneous release of gas and heat spontaneously or by contact with sparks or flame.

DHS 157.03(126)(126) “Exposure” means the quotient of dQ divided by dm where “dQ” is the absolute value of the total charge of the ions of one sign produced in air when all the electrons liberated by photons in a volume element of air having mass “dm” are completely stopped in air. The SI unit of exposure is the coulomb per kilogram. The standard unit of exposure is the roentgen.

DHS 157.03(127)(127) “Exposure head” means a device that locates the gamma radiography sealed source in the selected working position.

DHS 157.03(128)(128) “Exposure rate” means the exposure per unit of time, such as roentgen per minute and milliroentgen per hour.

DHS 157.03(129)(129) “External beam radiation therapy” means therapeutic irradiation in which the source of radiation is at a distance from the body.

DHS 157.03(130)(130) “External dose” means that portion of the dose equivalent received from any source of radiation outside the body.

DHS 157.03(131)(131) “External sinking fund” means an account, segregated from licensee assets and outside the licensee’s administrative control, into which monies are periodically deposited that are sufficient to pay decommissioning costs expected at the time licensee operations are terminated.

DHS 157.03(132)(132) “Extremity” means hand, elbow, arm below the elbow, foot, knee and leg below the knee.

DHS 157.03(133)(133) “Extremity bone densitometer” means a device that tests the mineral content of the bone of the fore arm, hand or foot.

DHS 157.03(134)(134) “FDA” means the U.S. food and drug administration.

DHS 157.03(135)(135) “Field emission equipment” means equipment that uses an x-ray tube in which electron emission from the cathode is due solely to the action of an electric field.

DHS 157.03(136)(136) “Field station” means a facility where radioactive sources may be stored or used and from which equipment is dispatched to temporary job sites.

DHS 157.03(137)(137) “Film badge” means a dosimeter containing radiation sensitive photographic film for measuring radiation dose plus various filters that characterize the type of radiation encountered. When developed, the darkness of the film is directly proportional to the amount of radiation received.

DHS 157.03(138)(138) “Filter” means material placed in the useful beam to preferentially absorb selected radiation energies.

DHS 157.03(139)(139) “Filtering facepiece” means a negative pressure respirator with a filter as an integral part of the facepiece or with the entire facepiece composed of the filtering medium, not equipped with elastomeric sealing surfaces and adjustable straps.

DHS 157.03(139m)(139m) “Fingerprint order” means an order issued by the NRC, a license condition by the department, or a legally binding requirement issued by another agreement state that requires a fingerprints and criminal history records check for individuals who have unescorted access to category 1 and category 2 quantities of radioactive material or safeguards information-modified handling.

DHS 157.03(140)(140) “Fissile material” means the radionuclides uranium-233, uranium-235, plutonium-239 and plutonium-241, or any combination of these radionuclides. Fissile material means the fissile nuclides themselves, not material containing fissile nuclides. Unirradiated natural uranium and depleted uranium, and natural uranium or depleted uranium that has been irradiated in thermal reactors only are not included in this definition.

DHS 157.03(141)(141) “Fissile material package” or Type AF package, Type BF package, Type B(U)F package, or Type B(M)F package means a fissile material packaging together with its fissile material contents.

DHS 157.03(142)(142) “Fit factor” means a quantitative estimate of the fit of a particular respirator to a specific individual, and estimates the ratio of the concentration of a substance in ambient air to its concentration inside the respirator when worn.