1、BRITISH STANDARD BS ISO 11599:1997 Determination of gas porosity and gas permeability of hydraulic binders containing embedded radioactive waste ICS 13.030.30; 13.030.40; 27.120.20BSISO 11599:1997 This British Standard, having been prepared under the directionof the Engineering SectorBoard, was publ
2、ished underthe authority of the Standards Board and comes intoeffect on 15 June 1998 BSI 04-1999 ISBN 0 580 29925 2 National foreword This British Standard reproduces verbatim ISO115991997 and implements it as the UK national standard. The UK participation in its preparation was entrusted to Technic
3、al Committee NCE/9, Nuclear fuel technology, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related internatio
4、nal and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in t
5、he BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are r
6、esponsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theISO title page, pages ii to iv, pages 1 to 15 and a back cover. Th
7、is standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No. Date CommentsBSISO 11599:1997 BSI 04-1999 i Contents Page National foreword Inside front c
8、over Foreword iii Text of ISO 11599 1ii blankBSISO 11599:1997 ii BSI 04-1999 Contents Page Foreword iii 1 Scope 1 2 Sample preparation 1 3 Measurement of open gas porosity 5 4 Measurement of gas permeability 8 Annex A (normative) Gas pycnometer 12 Annex B (informative) Bibliography 15 Figure 1 Level
9、ling of moulded sample 2 Figure 2 Sampling of homogeneous waste forms 3 Figure 3 Sampling of heterogeneous waste forms of block volume # 2m 3 4 Figure 4 Sampling of heterogeneous waste forms of block volume 2m 3 5 Figure 5 Gas pycnometer 7 Figure 6 Gas permeameter 10BSISO 11599:1997 BSI 04-1999 iii
10、Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a t
11、echnical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters
12、 of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard ISO 11599 wa
13、s prepared by Technical Committee ISO/TC85, Nuclear energy, Subcommittee SC5, Nuclear fuel technology. Annex A forms an integral part of this International Standard. Annex B is for information only.iv blankBSISO 11599:1997 BSI 04-1999 1 Introduction Hydraulic binder-based matrices can be hardened pu
14、re cement, mortar or concrete containing embedded wastes; these wastes can be radioactive or non-radioactive. It has been observed that the durability of these matrices, as well as the leaching rate of immobilized radionuclides in water are very largely dependent on gas open porosity and gas permeab
15、ility of the matrix. Also, permeability and open porosity can be related to the homogeneity of a hydraulic binder matrix. The objective of this International Standard is to offer a methodology that allows rapid estimation of the gas porosity and permeability of hydraulic binders. A direct comparison
16、 of the results obtained in different laboratories would thus be possible by checking the quality or ageing behaviour of a waste form. The International Standard, once implemented, would reduce discrepancies between laboratories. 1 Scope This International Standard describes the principles and metho
17、dologies of measuring both gas open porosity and permeability of hydraulic binder-based matrices used for immobilization of radioactive waste. The measurements can be carried out by using different apparatus designed and constructed on the basis of a few recommended characteristics. The measurements
18、 can be performed on samples prepared in a laboratory or taken from industrial production. Samples can be obtained by moulding or by coring a block. 2 Sample preparation The samples may be obtained either by moulding or by coring of a block. The choice shall be made according to the purpose of the s
19、tudy. 2.1 Moulded samples The samples are moulded when the hardened cement, mortar or concrete has been prepared either in the laboratory or taken from an industrial or pilot plant. 2.1.1 Sample size The sample shall be an orthogonal cylinder with square cross-section, or a rectangular parallelepipe
20、d. The acceptable sample length is in the range between (40 2) mm and (220 5) mm. The recommended length is (110 3) mm. The end orthogonalities in relation to the generating line direction shall be (90 1) . Straight section inherent flatness shall be 0,5mm. 2.1.2 Mould The sample is poured into moul
21、ds made of steel, plastic or cardboard with an inner sulfurized paper lining. Mould design shall allow withdrawal of the pattern from the mould without knocking flakes off the solid angle of intersection of the two surfaces. During mould filling, the mixture is stirred with a straight rod to elimina
22、te possible air bubbles. If drum vibration is arranged for an industrial process, the sample is compressed with a vibrating microtable. Levelling of the upper surface of the sample is carried out with a steel strip. The cross-section of the strip shall be trapezoidal with a 45 angle. The dimensions
23、of the strip shall be as follows: length: 450mm; width of the major base: 60mm; thickness: 15mm. In a first step, levelling enables a raw surface of a sample to be obtained using the strips chamfered edge (seeoperation A in Figure 1). In a second step, use the strips shorter base to obtain the final
24、 surface of the sample to be used (seeoperation B in Figure 1).BSISO 11599:1997 2 BSI 04-1999 Raw and final levellings are made with a sawing movement (an alternating movement). For each levelling, two passes are made with a change in direction of 90 . During levelling, cavities are filled with the
25、same mixture. All details of this operation shall be noted in the test report. 2.2 Core samples 2.2.1 General Core drilling is carried out with a tool adapted to the desired final diameter of the sample. During coring, over-heating of the tool can be damaging for the material; air or gas cooling sha
26、ll then be performed. A gas or air cooling filtration system shall be installed to avoid excessive radioactive contamination for tests with actual embedded radioactive or hazardous waste. The coring material, a cylindrical and tubular muff, is fitted with a diamond abrasive ring. The tools rotationa
27、l speed is defined for each manufacturers specifications. In the absence of specification, a rotational speed of 600min 1to 800min 1is recommended. In general, the core is cut into sections with a carborundum plate to obtain samples of a length suitable for tests. When a matrix with embedded waste i
28、s cored, the sample shall be chosen to differentiate homogeneous and heterogeneous parts. 2.2.2 Samples from homogeneous waste forms Figure 2 shows the procedure used. The cores are obtained in a direction parallel to the container axis, halfway between the centre and the lateral surface of the wast
29、e package. The core is then cut as shown in the diagram to obtain five samples. 2.2.3 Samples from heterogeneous waste forms Figure 3 shows the procedures used for samples from cylindrical or parallelepipedic blocks having a volume 2m 3 . Two vertical cores and three cross-cores can be obtained. In
30、this case, the number of samples is seven. If the integrity of the package is not guaranteed during these two procedures, it is possible to sample only on the top of the container. In this case, the statistic sampling representative will not be as accurate as in the procedure recommended above. Figu
31、re 1 Levelling of moulded sampleBSISO 11599:1997 BSI 04-1999 3 Figure 2 Sampling of homogeneous waste formsBSISO 11599:1997 4 BSI 04-1999 Figure 3 Sampling of heterogeneous waste forms of block volume # 2m 3BSISO 11599:1997 BSI 04-1999 5 3 Measurement of open gas porosity 3.1 Definition The sample o
32、pen gas porosity (P), expressed as a percentage, is the ratio of the open pore volume (V o ) of a sample to the geometrical volume (V g ) (also called the apparent volume). The open pore volume of a sample is also equal to the geometrical volume minus the real volume (V s ) of the sample. Thus, Figu
33、re 4 Sampling of heterogeneous waste forms of block volume 2m 3 .(1) V o= V gp V s .(2) .(3) P V o V g - = 100 P V g V s V g - = 100 BSISO 11599:1997 6 BSI 04-1999 3.2 Principle The determination of gas porosity is based on the measurement of the real volume of a sample, including the closed pores,
34、by the use of a helium pycnometer. NOTEThe theory of the gas pycnometer is given in Annex A. The following steps are carried out: drying the sample at 60 C until a constant mass is reached; measurement of the geometrical volume of the sample; measurement of the real volume of the sample. 3.3 Apparat
35、us The apparatus necessary for open gas porosity measurement comprises the following. 3.3.1 Oven, for drying the sample at a temperature of (60 2) C. 3.3.2 Desiccator, for cooling the sample before measuring its mass. 3.3.3 Scale, of capacity 0 to 5kg and an accuracy of 0,01 %. 3.3.4 Square caliper,
36、 of accuracy 0,1mm, for determining the geometrical volume of the sample. 3.3.5 Gas pycnometer, for measurement of the real sample volume, with a pressure accuracy of not less than10Pa. 3.4 Sample preparation The samples shall be obtained either by moulding or by coring and cutting. Several examples
37、 of sample preparation are given in clause2. Samples shall have a parallelepipedic or cylindrical configuration. 3.5 Procedure 3.5.1 Sample drying and weighing Dry the samples at (60 2) C in the oven (3.3.1) until constant mass is achieved. Constant mass is considered achieved when the difference be
38、tween two mass values measured using the scale (3.3.3) at a24h interval is lower than 0,1 % of the value in the previous measurement. Before any measurement of mass, cool the samples to ambient temperature in the desiccator (3.3.2). 3.5.2 Determination of geometrical volume Determine the geometrical
39、 volume (V g ) immediately after the mass measurement. 3.5.2.1 Cylinder diameter measurement Use the square caliper (3.3.4) for the diameter measurement. Make four measurements at each end and in the middle for the sample, turning the sample 45 after each measurement. The average diameter is the ari
40、thmetical mean of the twelve measured values. 3.5.2.2 Linear measurements For linear measurements, measure the cylinder height (H) or the sides of the parallelepiped (H 1 , H 2 , H 3 ). Make four measurements with the square caliper for each side of the parallelepiped and for the cylinder height, tu
41、rning the sample 45 after each measurement. The average height is the arithmetic mean of the four measured values. 3.5.2.3 Geometrical volume, V g Determine the geometrical volume of the sample from the following mathematical expressions: 3.5.2.4 Determination of real volume Determine the real volum
42、e (V s ) using a gas pycnometer immediately after determining the geometrical volume. Cylinder volume: .(4) Rectangular parallelepiped volume: .(5) D () H () V g ; D 2 H 4 - = V g H 1 H 2 H 3 =BSISO 11599:1997 BSI 04-1999 7 The gas pycnometer is shown in Figure 5; the theoretical basis for its use a
43、nd calibration procedures are explained in Annex A. Select the sample cell volume of the pycnometer so that the geometrical sample volume represents about75% of the total volume of the sample cell. Select the volume of the pycnometer reference cell so that the residual volume of the sample cell repr
44、esent about 15 % to 30 % of the total volume. The reference cells are generally filled with helium at normal pressure. If this is not the case, flush with helium, using an amount not less than twice the volume of the reference cell selected. Carry out helium flushing of the sample positioned in the
45、sample cell at low gas flow for 15min. Regulate the gas flow such that slow-rising single bubbles are observed in a beaker filled with water. Then stop the gas flow and isolate the sample cell from the atmosphere. Set the pressure pick-up at zero level. Now introduce helium gas into the reference ce
46、ll and pressurize at 100kPa to 120kPa. Wait 20s for pressure stabilization. Record this pressure as P 1 . Do not wait any longer for pressure stabilization because every 30s a pressure change of about 7Pa occurs due to temperature influence. Slowly turn the selector valve to connect the reference ce
47、ll with the sample cell. Wait 20s for pressure stabilization and record this pressure as P 2 . Record the volumes of the sample cell V cand reference cell V ron a data card. Figure 5 Gas pycnometerBSISO 11599:1997 8 BSI 04-1999 Calculate the real volume of the sample V susing the working equation (s
48、ee Annex A): Carefully open the toggle valve “gas out” to release the pressure from the cells and repeat the measurement process a second and third time to confirm the test reproducibility. 4 Measurement of gas permeability 4.1 Principle The following steps are carried out: placing the sample holder
49、 with a sealing gasket, placing the sample holder onto the apparatus and pressurizing the permeameter, measuring and recording the time-dependent pressure; measurements may be duplicated, data calculation and permeability determination. The value of the gas permeability can be found by studying the fluid flow through a sample. If a quasi-continuous and isothermal flow is assumed, and if the gas used is a perfect gas, the gas flow is
