Radiation protection

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Radiation protection at IBM and definitions

The purpose of the regulations is to ensure safe working conditions and prevent damage caused by radioactive radiation. The regulations apply to all staff members, PhDs, guests and students. The Head of the Department has the overall responsibility for the radioactive safety at the Department. The Department appoints radioactivity safety officers, one or more as needed, each having good knowledge of isotopes and radioactive hygiene. As well as detailed information regarding ongoing projects and are in a position to ensure that procedures in use abide to current requirements.

Group leaders have a supervising function in relation to work using radioactivity in the laboratory performed by technicians, PhDs, students and others.It is their duty to inform users on regulations and procedures related to the radioactive sources and doses that are being utilised.

Each individual is responsible for implementing the regulations and for using protective equipment.

Radioactivity safety officers at IBM:

5th floor: Endre Stigen

6th floor: Kirsten Marie Brønstad

7th floor: Tine Veronica Karlsen

Authorised users

A list showing authorised users shall be available in each isotope room and also in “Handbook for use of radioactive isotopes”, which shall be available in every isotope room.

All users of radioactive isotopes must have completed the course”Strålevern - ioniserende stråling” arranged by UiB, or to document a similar training. Those who for some reason have not been able to participate in this course or have no equivalent documentation must work under the supervision of an authorised person who is responsible for the work and that the waste is handled according to the guidelines.

Only certified users may obtain keys providing access to the isotope rooms, and these have to be procured from a radioactivity safety officer.

All exposure to radioactivity must be held as low as possible, and in any case not above 20 mSV per year for exposed workers.

In the case of pregnancy the fetus must not be exposed to a dose above 1 mSv. This means that pregnant women should avoid work with radioactive isotopes.

Definitions

Isotopes	Atoms of the same element can contain a different number of neutrons in the nucleus. These variants are called isotopes. Unstable isotopes are also defined as radioactive isotopes.
Ionising radiation	Radiation that has sufficient energy in the form of particles or electromagnetic waves to dislodge an electron from an atom and/or molecules and produce ions in biological material. It releases sufficient energy to break chemical bonds in DNA.
Particle radiation	α-, β-, neutron- and proton-radiation.
Electromagnetic radiation (photon-radiation)	X-ray and γ-radiation.
Radioactivity	A measure of the number of disintegrations (decay) per unit of time. The unit for radioactivity is becquerel (Bq). 1 Bq = 1 disintegration (breakdown of radioactivity, decay) per second.
Curie (Ci)	Earlier used unit of radioactivity. 1 Ci = 37 GBq (37 000 000 000 Bq = 3.7 x 10¹⁰ 1 GBq = 27 mCi).
Equivalent dose	Indicates the biological effect of ionising radiation. Depending on the type of ionising radiation the same dose can give different biological effects. The unit Sievert (Sv) is a rough estimate of how much ionising radiation will damage a living organism. The dose of radioactivity (the dose absorbed) is measured in Gray (Gy). 1 Gy = 1 joule absorbed energy per kg.
Exception limit	Borderline value measured in activity (Bq) and/or specific activity, for when a radioactive isotope can be omitted from the complete or parts of the radioactivity protection guidelines (strålevernforskriften).
Half-life	The half-life decay time is the time it takes for half of the material to be converted into its breakdown product (a measure of how quickly an isotope is broken down).
Short half-life	Shorter than 90 days.
Long half-life	Longer than 90 days.
Isotope death	An isotope dies after about 10x half-life decay time.
Geiger-Müller counter	Measures the activity of a radioactive substance.
Dosimeter	A device that measures exposure to ionizing radiation (value must be noted).
Plexiglass	See through plastic to screen β-emitters.
Perspex	Yellow plastic to screen β-emitters.

Weak/Strong emitters:

α-emitters	Radiation that is screened by paper/skin.
Weak β-emitters	Weak radiation that can be screened by clothing and gloves, however, direct exposure of large amounts should be screened using water, glass or plastic (perplex/plexiglass).
Strong β-emitters	Strong radiation that can be screened using water, glass or plastic (perplex/plexiglass).
Weak γ-emitters	Weak radiation that is screened by lead.
Strong γ-emitters	Strong radiation that is reduced/screened by lead.

Isotopes at IBM

Isotopes	Radiation	Half-life	Decay
³H (Tritium)	β-emitter (weak)	12.3 years (long)	With ¹⁴C)
¹⁴C (Carbon)	β-emitter (weak)	5730 years (long)	With ³H)
³⁵S (Sulphur)	β-emitter (weak)	87.3 days (short)	Alone
³²P (Phosphate)	β-emitter (strong)	14.3 days (short)	With ³³P
³³P (Phosphate)	β-emitter (strong)	25.4 days (short)	With ³²P
¹²⁵I (Iodine)	γ-emitter (weak)	60.1 days (short)	With ¹³³I
¹³¹I (Iodine)	γ-emitter (weak)	8 days (short)	With ¹²⁵I
⁵¹Cr (Chromium)	γ-emitter (strong)	27.7 days (short)	With ¹²⁵I and ¹³³I
²³⁸U (Uranium)	α-emitter	4.468 billion years (long)	Alone

Ordering, registration and storage

Radioactive isotopes can only be ordered by an authorized person and has to be certified by the Department´s administration. A copy of the order should be sent to the radioactivity safety officer and a copy of the package note has to be placed into the folder in the isotope room.

A γ-emitter can neither be ordered nor used before a radioactivity safety officer has given approval for both use and plans for waste management. The frequency of use of γ-emitters determines which level of security the isotope room must have, see section regarding use of the isotope rooms.

The Norwegian Radiation Protection Authority (NRPA, Statens strålevern) requires that one keeps an up-to-date overview of each isotope ordered. When receiving a new isotope it must be registered in a form (see attachments) found in the folder. Each time an aliquot is taken from the stock solution this has to be recorded in the form and the remaining amount noted. A new form is filled out for each new isotope received. These form the basis for the annual, mandatory reporting to the HES-section. This material is then forwarded to Statens strålevern.

All isotopes have to be stored in a lead shield receptacle, fridge or freezer in an isotope room.

Use of the isotope rooms

Isotope rooms are classified according to certain demands and specifications into types A, B and C dependent on activity level (web page in Norwegian).

Laboratory classification	Total activity at any given time in the laboratory
Type C	Up to 10 times the exception limit for radioactivity
Type B	Up to 10⁴ times the exception limit for radioactivity
Type A	More than 10⁴ times the exception limit for radioactivity

There are no type A rooms at IBM, and only two type B rooms (complete list bellow) where stock solutions are prepared, in addition to work with higher doses of isotopes.

All experiments with more than 50 MBq (1.35 mCi) of ³H, ¹⁴C and ³⁵S o 5 MBq (135 μCi) of ³²P must be carried out in type B isotope rooms.

The remaining isotope rooms are type C, complete list bellow.

Isotope room Type B:

Room nr	Description (info)
5C126B	When working with ³²P one must hang up a notice on the door outside in order to warn that such work is in progress. Here is a CO₂ incubator that can be used when labelling cells with either weak or strong β-emitters. Users are advised to reserve the incubator in advance.

Isotope room Type C:

Room nr	Description (info)
5C123aB	Scintillation counting.
6B141bA	Passage into scintillation counting and isotope rooms.
6B143bA	This room is to be used for all work with weak β-emitters (³H, ¹⁴C and ³⁵S) and ³²P below levels of 5 MBq or 125 mCi. In general hybridization and phosphorylation experiments involve use of low levels of ³²P-labeled nucleotides.
6B141aA	This room is for scintillation counting. One must not work with radioactivity in this room because of danger related to contamination of the counters. Only the addition of counting fluid to samples is allowed. Radioactive waste has to be placed in the isotope room.
7B125cY	Scintillation counting, beta-counter.
7C135eY	Two hoods with lead shields are found here. All labelling with radioactivity must be performed in this laboratory. This laboratory is furnished as a type B isotope room, but should be used as a C isotope room. After use the working space must be thoroughly cleansed and controlled to be sure there is no contamination.
7C135dY	Passage into isotope room 7C135eY.
7C137dY	Isotope storage with a lead storage cupboard.
7B131aY	Scintillation counting, gamma-counter. Can be used for intermediate storage of samples prior to counting if needed.
7C137cY	Cold-room for waste. Intermediate storage of radioactive biological waste from grey zone.

If small doses of radioactivity are used in a place other than an isotope room, then the working area has to be labelled with yellow tape bearing radioactivity symbols. The rooms that are used for the everyday collection of radioactive waste, as well as all isotope rooms must be locked when not in use.

Experimental rooms in grey zone:

Rom nr	Description (info)
7B128Y	Experimental laboratory. A freezer for storing samples temporary.
7B134Y	Experimental laboratory.
7B140Y	Experimental laboratory.
7B146Y	Experimental laboratory.

Safety equipment

Perspex-/plexiglass- screens, monitors (Geiger-Müller counters), goggles, gloves, masks, lead blocks and lead coats are available in the isotope rooms.

All reusable safety equipment must be returned to their original position after use.

NB! The hoods only contain lead (2/10 mm) in the walls and in the moveable shield in the front. When working with ³²P plexiglass shielding must be used in addition between the radioactive source and the lead shielding in order to prevent secondary radiation.

For general information regarding safety equipment please refer to the chapter on Personal protection and safety measures.

Log books

Each isotope room shall contain a log book.

Every time a radioactive source is used (opened) it shall be noted in the log (see registration form and attachments).

In the log book is shall be noted how much of the isotope is used, how much liquid and solid waste is placed in the waste container (bq), date of the experiment, full name of user and a signature for the contamination control.

Contamination control

All laboratories shall be controlled for radioactive contamination every month, or more often if necessary (wipetest). This is performed by rotation between the users and a control form is filled out. If there are few users for an extended period of time the room must be controlled and radioactive waste removed after each experiment.

Wipetest:Wipe over the area with 3x1 cm strips of filter paper or Q-tips moistened with Deconex (or some other recommended detergent), and number them according to the area controlled. Allow the strips to dry and place them in scintillation vials with counting fluid. Repeat the test until no contamination is detectable.

Control sheets (see attachment) are archived in a separate logbook kept in each isotope room.

General security procedures

Routine procedures:

Work has to be planned in detail
Always use a lab coat and gloves
Spread a plastic-based cover over the working surface. If there is production of vapors, gas or particles, then the work must be carried out in a hood. All tubes/glass receptacles have to be marked clearly.
All samples/glasses must be properly labelled
Use as limited working space as possible when working with isotopes and only use low levels of radioactivity
Keep a distance to the radioactive source and work for as short a time as possible with an open source
Shield the source and use personal protective equipment. Remember that a shield that is too thin can result in unwanted secondary radiation
Avoid spill of radioactive material, tidy up and clean the working area after use
Radioactive waste shall be removed as previously indicated
Check the area where work was performed and your clothing with a Geiger-Müller counter
Use a dosimeter/fingerdosimeter to measure the total level of radioactivity you have been subjected to during your work (only applicable when strong β-emitters or γ-emitters have been used)

NB! In the case of an accident or a substantial spill then one must immediately contact a radioactivity safety officer

Special routines for work with β-radiation

³H and ¹⁴C are nuclides with relatively low energy. There is little radiation involved but they should be treated as poisonous chemicals. The greatest danger relates to intake into the body.

Remember:

32P + lead should not be used together - 32P + Plexiglass is acceptable.

32P + Plexiglass + lead is acceptable, but lead is usually not necessary.

Special routines for work with γ-radiation

Gamma waves have an effect over a long distance. The intensity is reduced proportionally with the square of the distance. One must make sure that one follows the defined security regulations; lead, lead coat and distance, as preventive measures both for yourself and others.

Treatment of waste

The handling of radioactive waste is described under waste management.

But remember:

UiB has zero tolerance for spills of all kinds of chemicals into the sink/sewer system.
The different nuclides must as far as possible be collected and packed separately.
In addition to the type of isotope(s), activity quantities (Bq), name and date for each box, the weight of the box must also be indicated.
Fill out the form for hazardous waste also for radioactive waste, the waste-coordinator will then be notified automatically.

Treatment of Uranyl acetate in the EM-lab

Uranyl acetate is an α-emitter. Radiation is hindered by a few cm of air, but the compound is extremely harmful on contact with skin (hands) or if it is taken up by the lungs or the gastrointestinal system. Always use appropriate gloves when handling uranyl acetate.

All uranyl acetate must be stored in a locked, ventilated metal storage cupboard. When weighing out the compound do this in a fume cupboard, use a type-3 mask (supplier: Victoria) and gloves. Use a 1-2% aqueous solution.

Waste is poured into collection bottles that are stored in a locked metal cupboard. When the bottle is full (500ml), the waste is treated as radioactive waste with a long half-life storage time. Used filter paper, gloves, cleaning tissues and parafilm etc. (dry waste) are taken to the receptacle for waste collection in the isotope room.

Additional information

For more information see:

Regulations on radiation protection and use of radiation (Norwegian only)
Use of open radioactive sources in laboratories (Norwegian only)
Guidelines for radiation protection and use of radioactivity at UoB (Norwegian only)
Guidelines for disposal of hazardous and problematic waste, radioactive sources and explosive waste (Norwegian only)

Attachment

Vedlegg finnes i denne pdf-filen

Attachment contains:

I	Registration, description of the research project
II	Ordering sheet/Sheet for registration and storage of radioactive isotopes
III	Sheet for registration of waste
IV	Wipe-test control form, map of the isotope rooms in 5th, 6th and 7th floor
V	Map of the waste rooms in the 1st floor