Classification/separation

Radioactive waste can be divided into:

• Gaseous radionuclides
• Solid radioactive waste
• Liquid radioactive waste and scintillation liquids
• Radioactive substances in the form of sealed radiation sources
• Lead containers (not radioactive themself, but in which radiation sources have been stored)

As far as possible, radioactive substances must not be mixed with other kinds of waste.

Written procedures for the handling of radioactive waste, the estimation of the activity in the waste, the measurement of the surface dose rate and the estimation of the activity of the air emissions are set out in the University’s ”Radiation Safety Manual” (joint quality manual for radiation protection for the Royal Institute of Technology KTH and Stockholm University).

Handling/storage

Radioactive substances must be stored under lock and key so that they are not accessible to unauthorised persons. The storage must be satisfactory in terms of fire protection. The storage site must be screened off so that the dosage rate does not exceed 20 µSv/h in areas where people circulate or no more than 2 µSv/h in areas used by someone on a permanent basis. The storage site must be easy to clean. If volatile substances are held there, or if there is a risk that such substances may be formed, the storage site must be well ventilated. The storage site must be marked with a warning sign for ionising radiation, the text “Storage site for radioactive substances” and “Storage site for radioactive waste” respectively, and the name and phone number of the person who is responsible for the storage site. A container for radioactive waste must be of a suitable material and design in the light of the chemical and physical properties of the substance being stored. The container must be marked with the designation of the radionuclide and information about its activity on a given date. What is said above shall also apply to the storage of radioactive waste pending final disposal.

Gaseous radionuclides

In activities where gaseous radionuclides are produced or generated from systems with labelled radioactive substances, the contribution to the radiation dose from the emissions to a representative person is estimated and the information and the method used to calculate the correlation between the activity released and the effective dose must be documented. A party who conducts such activities shall make a report to the Radiation Protection Authority no later than 1 March each year of the activity released per radionuclide for the previous calendar year. The radiation protection expert must always be consulted before an activity that can give rise to air emissions is started.

Solid radioactive waste

All solid waste (paper balls, plastic, glass, etc) and solutions, precipitates, filtrates, etc. containing radioactive substances must be disposed of as radioactive waste. Work with radioactive substances must be planned so as to minimise the quantity of waste that must be disposed of as radioactive waste.

The radioactive waste must be packed in a waste container, a well-sealed internal plastic bag and, if the waste is or can become a liquid, absorbant corresponding to twice the quantity of waste in liquid form.

Maximum permitted activity level per waste package

The total quantity of radioactive substances per waste package must not exceed the quantity of activity specified in SSMFS 2010:2. The dosage rate on the surface of a waste package submitted to a combustion plant must not exceed 5µSv/h.

Summation rule

When several radioactive substances are placed in one and the same waste package the following restriction is applicable

Σ_k(A_k/L_k) ≤ 1

Where A_k is the activity of radionuclide k and L_k is the limit value for the same nuclide.

The total activity of the waste submitted to a combustion plant from a laboratory during a calendar month must not exceed ten times the activity stated in SSMFS 2010:2.

Example: Can 1 MBq P-32 and 5 MBq C-14 be placed in the same container and sent for waste combustion for final disposal as radioactive waste?

Reply: Divide each activity value by the corresponding limit value from SSMFS 2010:2 and add up the result: 1 MBq/0,1 MBq = 10 for P-32 and 5 MBq/10 MBq = 0.5 for C-14, the sum of 10 + 0.5 gives the value 10.5.

This value exceeds the summation rule value of no more than 1, so the container must not be sent for waste combustion, at least not yet.

Measure: In this specific case the container and its contents have to decay for 16 weeks. P-32 has a half-life of 14 days, which means that the summation rule value will fall under 1 after 8 half-lives and the container can be marked and sent for combustion.

Liquid radioactive waste and scintillation liquids

Scintillation liquids are still often classified as hazardous chemical products. These must not be poured out in the slop sink for liquid radioactive waste and must be packed in plastic or glass bottles placed in a container for hazardous waste together with a sufficient quantity of absorbent to prevent leakage during transport.

Most scintillation liquids contain NPE (nonyl phenol ethoxylate). This substance is listed in Council Directive 2003/53/EC and must not be discharged into any water system within the European Community and must always be sent for final disposal by combustion.

The total activity of the waste washed out in drains from a laboratory during a calendar month must not exceed ten times the activity stated in SSMFS 2010:2. The waste washed out at one and the same time must not exceed the activity stated in SSM FS 2010:2. The same summation rule as for waste for combustion applies to releases to drains. Each discharge must be washed down with plenty of water. At every discharge point there must be a clearly visible sign saying that liquid radioactive waste may be washed down the drain.

Flammable scintillation solutions must always be packed in small plastic and glass bottles with an aggregate volume of no more than 1 litre per waste container. Absorbent must be added to the vessel; the quantity must correspond to a capacity to absorb at least double the quantity (2 litres) of liquid.

for non-flammable liquid scintillation solutions, no more than 5 litres may be packed in a waste container with a sufficient quantity of absorbent.

Radioactive substances in the form of sealed radiation sources

Under the regulations (SSM FS 2010:2) sealed radiation sources with an activity quantity of no more than 50 kBq may be sent for waste combustion. If there is the slightest uncertainty about the activity of the sealed radiation source to be disposed of, contact the University's radiation protection expert Mats Jonsson (08-790 9123, matsj@kth.se) or Mats Hansson at the Section for safety and security (08-16 2251, mats.hansson@su.se).

Lead container

The lead containers used for delivery of isotopic solutions or other radioactive materials can, free of charge, be deposited on Wednesdays and Fridays at 10.30–11.00 in room M212 at KÖL (Chemical Education Laboratories), Svante Arrhenius väg 16F. The waste contractor checks the containers regarding radiation before they are transported for recycling.

Documentation

There must be documentation of:

• stored waste of radionuclides with a half-life of >10 h, stating the nuclide, activity and surface dose ratio on a particular date, origin and identity with traceability to a waste container.
• annual activity of radionuclides with a half-life of >10 h that have been sent to a combustion plant or have been washed down a drain.
• annual activity that has been released to the air.
• activity of waste that has been sent to an approved waste plant.

The documentation must be retained for at least five years after the final disposal of the waste.

Marking/labelling

Stockholm University waste label filled in with:

• Radioactive: (x)
• Type of waste, specification: Radionuclide, activity and surface dose rate at the specified date
• Submitting department, department number and reference
• Submitter’s name, phone no and date

The warning symbol for ionising radiation must also be stuck on the waste container.

The quantity of activity in each individual waste package must not, on deposit for transportation to the waste contractor, exceed the limit value given in SSM FS 2010:2.

Hand-over/transport

Radioactive waste in accordance with these restrictions can be deposited on Wednesdays at 09:45–10:15 in room A205 (opposite the SU Shop). The waste contractor then transports the waste for destruction.

Radioactive waste that does not meet the restrictions according to these instructions and SSMFS 2010:2 must be taken charge of by Studsvik Nuclear AB. In such cases the University’s radiation protection expert and SEKAs safety adviser must always be contacted since other requirements under the ARD-S transport regulations and requirements concerning reporting to the permit authority must also be complied with.

Final disposal

Combustion arranged by the waste contractor.

Specific legislation

SFS 1988:220      Radiation Protection Act

SFS 1988:293      Radiation Protection Ordinance

SFS 2007:193     Ordinance on Producer Liability for Certain Radioactive Products and Orphan Radioactive Sources

SSMFS 2009:1    Control of Cross border Transports of Radioactive Waste and Spent Nuclear Fuel

SSMFS 2010:2    Handling of Radioactive Waste and Discharges from Activities with Open Radiation Sources