ISO 18213-4-2008 PDF

Full title and description

St ISO 18213-4-2008 — Nuclear fuel technology — Tank calibration and volume determination for nuclear materials accountancy — Part 4: Accurate determination of liquid height in accountancy tanks equipped with dip tubes, slow bubbling rate. This part of ISO 18213 specifies procedures and measurement practices for accurately determining liquid height in accountancy tanks using pneumatic dip‑tube systems operated at very slow bubbling rates.

Abstract

ISO 18213-4:2008 specifies a procedure for making accurate determinations of the liquid height in nuclear‑materials‑accountancy tanks that are equipped with pneumatic dip‑tube systems. The procedure covers measurement principles when gas is forced through a submerged probe and the pressure required to induce bubbling is measured; it is written specifically for the slow bubbling‑rate condition and includes guidance to reduce bias and uncertainty in height determination.

General information

• Status: Published (International Standard).
• Publication date: March 2008.
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 27.120.30 (Nuclear materials and fuel technology).
• Edition / version: Edition 1 (2008-03).
• Number of pages: 21.

Scope

This part of ISO 18213 applies to accountancy tanks used in nuclear fuel technology that are fitted with dip tubes and pneumatic bubbling systems. It defines a measurement procedure and related conditions for determining liquid height when a very slow bubbling rate is used, and it addresses measurement set‑up, instrument location, corrections and uncertainty considerations relevant to accountancy‑grade volume determinations.

Key topics and requirements

• Measurement principle for dip‑tube (bubble) methods at slow bubbling rates.
• Recommended set‑up: probe/dip‑tube configuration, manometer placement and plumbing considerations to minimise systematic error.
• Procedure for recording the pressure at the onset of bubbling and converting that to liquid height.
• Corrections for gas column, temperature and vapor pressure effects where relevant.
• Uncertainty evaluation and guidance to achieve accountancy‑level accuracy for volume/height determinations.

Typical use and users

Primary users are nuclear materials accountancy and safeguards personnel, metrology and calibration laboratories supporting nuclear facilities, nuclear fuel manufacturers and plant operators, and regulators who require documented, reproducible procedures for tank height and volume measurements used in material balance and safeguards. Practitioners use this standard when implementing or auditing dip‑tube liquid height measurement systems under slow bubbling conditions.

Related standards

ISO 18213 is a multipart series addressing tank calibration and volume determination for nuclear materials accountancy. Related parts include ISO 18213-1 (procedural overview) and other parts covering alternative bubbling rates and in‑tank density determinations (for example Parts 3, 5 and 6 in the 2008 series). National adoptions and identical publications of other parts are available through national standards bodies.

Keywords

nuclear fuel technology, tank calibration, volume determination, accountancy tanks, dip tube, dip‑tube bubbling, liquid height measurement, slow bubbling rate, metrology, safeguards

FAQ

Q: What is this standard?

A: ISO 18213-4:2008 is an International Standard that specifies a procedure for accurately determining liquid height in accountancy tanks equipped with dip tubes when using very slow bubbling rates.

Q: What does it cover?

A: It covers the measurement principle, recommended instrumentation and set‑up, pressure measurement for bubbling onset, conversions to liquid height, necessary corrections and how to evaluate measurement uncertainty for accountancy‑grade determinations under slow bubbling conditions.

Q: Who typically uses it?

A: Nuclear materials accountancy officers, safeguards inspectors, calibration and metrology labs supporting nuclear facilities, plant operators and regulators use the standard to ensure reproducible and auditable tank height/volume measurements.

Q: Is it current or superseded?

A: The document was published in March 2008 as Edition 1. Sources consulted list it as the published part of the ISO 18213 series; users should consult ISO or their national standards body for the absolute current status or any later amendments or confirmations.

Q: Is it part of a series?

A: Yes — ISO 18213 is a multipart series on tank calibration and volume determination for nuclear materials accountancy; Part 4 addresses slow bubbling‑rate liquid height determination while other parts handle overview, alternative bubbling rates and related measurements.

Q: What are the key keywords?

A: Nuclear fuel technology, tank calibration, volume determination, accountancy, dip tube, bubbling rate, liquid height, metrology, safeguards.