Escalating Decontamination by Surface and State

Who this page is for, and what it answers

Decontamination begins with the easiest method and moves up to the more complex. Alongside that escalation, two things are looked at: the state of the contaminating material and the type of surface it has landed on. This is the substance of three clauses of article 1 of the instructions in decision 3 of 2007, in our words. The Arabic wording itself is carried verbatim in the section below; we do not reproduce the law's wording in English.

Five terms are needed on this page. The contaminating material is the radioactive material that has landed on the surface. Its chemical and physical state is the condition the material is in, which the text illustrates with greasy and oily material and with dust and liquid. A porous surface is one with fine openings that take up liquid. A decontaminating agent is whatever is used to remove the contamination, whether water, a detergent or a chemical. And the licence holder is the party holding the licence to deal with radioactive material.

The page is for the radiation protection officer in a laboratory. It is for whoever writes a written decontamination procedure. And it is for whoever reviews such a procedure and wants to know whether it orders the methods from the easiest upwards.

Where this sits in the text: clauses 2, 3 and 4 of article 1 of the instructions attached to the decision, not of its two enacting articles. Clause 1 of the same article sets numerical limits and has its own published page in this series.

The most important caution: the four methods named in clause 4 are examples and not a closed list, introduced as illustration and closed with a general catch-all. So whoever counts them as four and treats that as a ceiling has read something other than what is written.

The escalation itself is required by the wording, while the rungs are given as examples. So what is required is the order from the easiest, not the use of these four in particular. That is our reading of the form of the wording.

There is no measurement figure in these three clauses. They name no unit of radioactive activity and no area of surface over which a rate is worked out. The limits and their areas sit in clause 1 and in other articles, which have their own published pages. Numbers from one place are not imported into another.

The three clauses, in our rendering

Clause 2 requires that the material and the surface both be considered. It provides that, in order to reduce the level of radioactive contamination, the chemical and physical state of the contaminating material must be taken into account, as well as the nature and type of the contaminated surface, which may itself be affected by the decontaminating agents. So two things are considered: the state of the material, and the nature and type of the surface.

The states of the material are given as examples: greasy, oily, in the form of dust, or liquid. The types of surface are given as examples too: plastic, metal, or porous. In both places the introducing word marks illustration, not limitation.

Clause 2 also carries an express caution about the surface itself: the surface may be affected by the decontaminating agents. That the surface may be so affected is stated in the text and is not a reading of ours. That it may be damaged is our own technical explanation.

Clause 3 requires a suitable cleaning agent. It provides that suitable cleaning materials must be used for decontamination, and that conventional detergents available in the local markets may be drawn on. So the stated test is suitability, and the permission to use ordinary market detergents is stated as well.

Clause 4 requires escalation. It provides that decontamination must proceed by degrees, from the easier methods to the more complex ones, as by using ordinary water, pressurised water, water mixed with chemicals, or complex chemical agents, among others. So the rule is a progression from the easier methods to the more complex.

The four examples are named: ordinary water, pressurised water, water mixed with chemicals, and complex chemical agents. The list then closes with a general catch-all, so the door is open to methods besides these.

What falls outside these clauses

These clauses give no permitted limit. Anyone looking in them for an acceptance figure will not find one. The limits sit in clause 1 of the same article and in other tables, which have their own published pages.

These clauses do not deal in detail with tools and vessels, nor with surfaces and benches, nor with clothing. Those sit in other articles, whose pages are in this same batch.

They do not deal with what is done when an incident occurs, or with notifying it. That is another article of the instructions, with its own published page. These are clauses about removal and not about emergencies.

They do not deal with handling the waste that removal produces. That sits in another article, with its own page in this batch. The instructions on managing radioactive waste are a separate instrument; we name them as a reference and do not quote them here.

The places we have read in these instructions contain nothing on penalties and nothing on a transition period. What we have not read, we do not judge.

The four examples listed in the order of the text

The table below lists the four examples in the order they are mentioned. Skip it on a first reading; the explanation above carries the point.

The middle column renders the names of the four methods, in the order the text gives them. The last column is our reading of what the text does not state, and is not drawn from it. The numbers in the first column are ours, and the order they mark is the text's. The table carries no measurement figure and no limit, because these clauses contain none.

A case of an oily spill on a porous surface, and four steps

Suppose an oily radioactive solution spills on a rough, porous floor. The state of the material is oily and the surface is porous. Clause 2 requires that both be considered before an agent is chosen. Clause 4 requires starting with the easiest method. Had the worker begun with a complex chemical solvent, he would have departed from the escalation the text sets. Had he raised the pressure on a porous surface, he would have driven the contaminant into it. That is our technical explanation and not a provision in the clause.

Step one: consider the state of the material and the type of surface before you choose an agent; clause 2 requires that much. Writing down what you considered is a recommendation of ours for review, not a provision of the clause.

Step two: order your written procedure in degrees from the easiest to the most complex. The order of the text's examples is ordinary water, then pressurised water, then water mixed with chemicals, then complex chemical agents. These are the names the text gives as examples, and they are not a closed list. Our reading: pressurised water raises a spray and carries contamination beyond its place, and whether it suits a surface is for the protection officer to judge.

Step three: tie each degree in your procedure to what the surface can bear. Clause 2 states that the surface may be affected by the decontaminating agent. Where the limit of what a surface can bear lies is our reading, and the text does not state it.

Step four: record what you used at each degree and what you read afterwards. A procedure without a record cannot be reviewed. The protection officer removes, records and reports to the licence holder: this is what we train for, not what we do for you.

Questions people ask

Notes on transcription and reading

What we work from is a written transcript, not a scanned image. These three clauses are sound in transcription: they contain no symbol and no figure whose reading is in doubt. So we have withheld nothing from this page. Another article of the instructions has a place we withheld, and it is declared on its own page.

The three clauses are alike in carrying an obligation, and we do not level what differs in them. Clause 3 adds a permission, and that permission concerns conventional detergents and not the duty itself.

A point on which the text is silent: the clauses do not say who decides that the easier degree has not sufficed. Whether the protection officer decides by measurement or by eye, they do not say. We have not asked the competent authority, so we report no view of theirs.

What the institute offers, its limits, and the reference

This page is about the escalation of removal methods and the effect of the material's state and the surface type. The institute trains radiation protection officers to write a procedure ordered from the easiest method upwards and to document it.

ALDuha Institute for Training and Environmental Consulting works in training and consulting. Its training is licensed. It does not run a laboratory analysis service for smears. It does not calibrate radiation survey instruments. It does not test equipment or certify it as safe. It does not carry out decontamination in a laboratory or on a site.

The institute does not provide first aid, treatment or medical assessment. We train people to read the text and to write down what happened.

Decontamination is the work of the licence holder and his radiation protection officer. Where outside expertise is needed, it is arranged through specialist partners. We train people to read, measure and document. We do not do the work in place of the licence holder.

Neither our training nor our consulting gives any undertaking that a licence will be issued. There is no undertaking about how long an approval will take. That decision belongs to the competent authority alone.

Reference: decision 3 of 2007 of the chairman of the Supreme Council for the Environment and Natural Reserves, on radioactive decontamination instructions. Location: clauses 2, 3 and 4 of article 1 of the attached instructions. The decision rests on decree law 31 of 2002, and on the executive regulation issued by decision 4 of 2003. The decision's own preamble points in particular to article 17 of the first and article 97 of the second. We name the two enabling instruments and carry the preamble's reference to them, and we do not quote their text.

A note on the names of authorities: the decision was issued by the Supreme Council for the Environment and Natural Reserves. The authority addressed today is the Ministry of Environment and Climate Change, which houses the Radiation Protection Department. The name has changed; the duty remains.

This page is an introductory explanation of a published text, and is not a legal opinion. It does not replace reading the decision itself. It does not replace checking with the competent authority.