ISO 12807:2018 放射性物質の安全な輸送—パッケージの漏れテスト | ページ 6

3.18.1

漏洩検知器の感度

トレーサー流体の漏れに対する検出器の使用可能な最小応答、つまり検出器の読み取り値に再現性のある変化をもたらす漏れ率

3.18.2

漏れ検査手順の感度

試験手順で検出できる最小検出可能漏れ率

3.19

標準化された漏れ率

一眼レフカメラ

既知の条件下で評価した漏れ率。上流圧力 1.013 × 10 ⁵ Pa, 下流圧力 0.0 Pa, 温度 298 K (25 °C) の基準条件における乾燥空気の流れに対して正規化

注記 1:標準化された漏れ率の単位は、Pa m ³ s ⁻¹ SLR と表記されます。

3.20

標準化されたヘリウム漏れ率

シェルR

ヘリウム漏洩率、既知の条件下で評価、上流圧力 1.013 × 10 ⁵ Pa, 下流圧力 0.0 Pa, 温度 298 K (25 °C) の基準条件における乾燥ヘリウムの流量に正規化

注記 1:標準化されたヘリウム漏洩速度の単位は、Pa m ³ s ^-1 (SHeLR) と表記されます。

3.21

テストガスまたはトレーサーガス

漏れの検出または漏れ率の測定に使用されるガス

3.22

粘性流

リークの横断面の最小寸法と比較して平均自由行程が非常に小さいような条件下でのリークを通るガスの連続的な流れ。

注記 1:この流れは層流または乱流のいずれかである可能性があります。粘性流は全圧勾配に依存します。

3.1

activity release rate

loss of radioactive contents per unit time through leaks or permeable walls of a containment system

3.2

blockage mechanism

mechanism by which radioactive material might be retained within a containment system due to blockage of potential leakage paths by solid or liquid material

3.3

competent authority

any national or international authority designated or recognized as such for any purpose in connection with the International Atomic Energy Agency (IAEA) Regulations for the Safe Transport of Radioactive Material and other applicable regulations

3.4

containment system

assembly of components of the packaging intended to retain the radioactive material during transport

3.5

gas leakage test methodology

method of specifying a gas leakage test which relates permissible activity release rates of the radioactive contents carried within a containment system to equivalent gas leakage rates under specified test conditions

3.6

leak

any unwanted opening or openings through a containment system that could permit the escape of the contents

3.7

leakage

transfer of a material from the containment system to the environment through a leak or leaks

Note 1 to entry: See also permeation (3.14) .

3.8

leakage rate

quantity of solid particles, liquids or gases passing through leaks per unit time

Note 1 to entry: The term leakage rate can refer to the radioactive material (gas, liquid, solid or any mixture of these) or to the test fluid.

Note 2 to entry: The dimensions of the rate of solid leakage are mass divided by time. The dimensions of the rate of liquid leakage can be mass divided by time or volume divided by time. The dimensions of the rate of gas leakage are the product of pressure and volume (this is a mass-like unit) divided by time at a known temperature.

3.9

leaktight

general term indicating that a containment system meets the required level of containment for particular contents

Note 1 to entry: See Clause 8 in Annex E.

3.10

medium

any fluid, which might or might not be radioactive itself, which could carry radioactive material through a leak or leaks

3.11

molecular flow

flow of gas through a leak under conditions such that the mean free path is greater that the largest dimension of a transverse section of the leak

Note 1 to entry: The rate of molecular flow depends on the partial pressure gradient.

3.12

package

packaging together with its radioactive contents as presented for transport

3.13

packaging

assembly of components necessary to enclose the radioactive contents completely

3.14

permeation

passage of a fluid through a solid permeable barrier (even if there are no leaks) by adsorption-diffusion-desorption mechanisms

Note 1 to entry: Permeation should not be considered as a release of activity unless the fluid itself is radioactive. In this document, permeation is applied only to gases.

3.15

permeation rate

quantity of gases passing through permeable walls per unit time

Note 1 to entry: The permeation rate depends on the partial pressure gradient.

3.16

qualitative

refers to leakage test procedures which detect the presence of a leak but do not measure leakage rate or total leakage

3.17

quantitative

leakage test procedures which measure total leakage rate(s) from a containment system or from parts of it