Frequently Asked Questions about Dosimetry

Article 7.17 of the Decree on Basic Safety Standards for Radiation Protection states that the citizen service number must be submitted as part of the employee's identification. The dosimetry service only uses this number to perform its tasks and only makes it available to the NDRIS, the National Dose Registration and Information System. The privacy policy of the dosimetry service is laid down in the terms of delivery available on the website www.dosimetrie.nl.

If a dose result is higher than the set warning level, the client will be notified immediately by e-mail. If desired, this person can then start an investigation into the reason for this dose without first having to wait for the dose report. The height of the warning level is set to the value 1 mSv by default. When using the web application, it can be changed yourself.

In principle, this is a matter for the person responsible for radiation hygiene supervision at the customer (the responsible expert as mentioned in the application for the Nuclear Energy Act permit).

It depends on how high the dose is. A value of 0.01 – 0.05 mSv is so low that no immediate action is required. At this level it is not immediately clear whether the reported dose is the result of a variation due to measurement uncertainties in the readings, variation in the natural background signal or is actually caused by a radiation source at the employer. If the reported dose is higher than 0.05 mSv, then there has generally been exposure to a radiation source.

For the purpose of monitoring and supervision, a distinction is made between unexposed and exposed employees. Exposed employees are in turn divided into A and B employees. The classification is related to the radiation dose that said employees can receive in a calendar year. With regard to the effective dose, the following applies:

• Non-exposed worker: less than 1 mSv per calendar year
• Exposed worker: 1 – 20 mSv per calendar year
• B employee: 1 – 6 mSv per calendar year
• A-employee: 6 – 20 mSv per calendar year

For the dose limits of a number of organs per type of employee, reference is made to Articles 7.3 and 7.11 of the 'Decree on Basic Safety Standards for Radiation Protection'. In general, the entrepreneur's radiation expert is responsible for the classification of the employees.

The obligation to wear a dosimeter applies to exposed workers. These are workers who may receive an effective dose of 1 mSv or more per calendar year or who may exceed the dose limit for unexposed workers for the lens of the eye or the skin. The emphasis is on the words 'being able to receive'; Unusual situations must also be taken into account via an RI&E (Risk Inventory and Evaluation).

There is no legal obligation for other employees. However, the employer can use the results of the personal dosimeters to check and quantitatively substantiate the effectiveness of radiation hygiene measures. Wearing personal dosimeters therefore makes a positive contribution to awareness of radiation risks.

The Regulation 'Radiation Protection for Occupational Exposure 2018' stipulates that for exposed employees the maximum time between two readings of a personal dosimeter is five weeks. Exposed workers are workers who may receive an effective dose of 1 mSv or more per calendar year. The emphasis is on the words 'being able to receive'; Unusual situations must also be taken into account via an RI&E (Risk Inventory and Evaluation). If it follows from this RI&E that your employees no longer need to be classified as exposed employees, you can switch to quarterly dosimeters.

The reason given for this question is often that no significant doses have been received by employees in recent years. This is confirmation that the rules are being adhered to and that radiation hygiene is well under control, but in itself it does not constitute proof for switching to quarterly dosimeters.

Radiation hygiene care is the responsibility of the employer. The legal rules regarding pregnancy are laid down in Article 7.36 of the 'Decree on Basic Safety Standards for Radiation Protection'. The entrepreneur must ensure that the equivalent dose for the unborn child is as low as reasonably possible and that this dose will not exceed 1 dose from the moment the pregnancy is reported to the entrepreneur until the end of the pregnancy. mSv.

To check the 1 mSv limit, it is recommended to request an additional dosimeter in the name of the pregnant employee that he or she can wear on the waistband (if using a lead apron: under the lead apron). The dose on this dosimeter is reported in the employee's name but under a different serial number. The (cumulative) dose result from this subscription can be used as an (equivalent) dose for the unborn child. After the pregnancy, the employer must arrange for this extra dosimeter to be canceled again.

How long the entrepreneur must keep the dose data depends on the category classification of the employees concerned. Article 7.16 of the 'Decree on basic safety standards for radiation protection' states that a number of data must be kept separately for each exposed employee, including the dose results. These data must be kept until the employee concerned has reached or would have reached the age of 75, but at least 30 years after this person has ceased work. An exposed worker is a worker who may receive an effective dose of more than 1 mSv in a calendar year.

Local laws and regulations in the relevant country apply. The dosimeters from Mirion Dosimetry Services are recognized by the Dutch government, but not elsewhere. If one is not required to wear a dosimeter for the work in question, there is no objection to using the dosimeters from Mirion Dosimetry Services. In this way, the employer keeps track of the radiation hygiene situation within his company and is better prepared for any future claims.

Whether the employee needs a dosimeter depends on the radiation levels at which the work is performed and the locally applicable rules. In any case, taking a dosimeter with you cannot hurt and, as the person responsible for the well-being of your employees, it gives you information about the risks run by the employee. If the employee in question already has his/her own personal dosimeter, Article 7.19 of the 'Decree on Basic Safety Standards for Radiation Protection' stipulates that he/she must also use this dosimeter abroad in that case.

Because luggage is now extensively scanned (airports, hotels) using X-ray equipment, it is recommended to take two dosimeters per employee, the personal dosimeter and a transit dosimeter. During the journey, both dosimeters are located close to each other in the luggage; After arrival, the personalized personal dosimeter is worn, while the transit dosimeter remains in the luggage. On the return trip, the dosimeters are put back together in the luggage. The difference in the result between the two dosimeters indicates the dose received by the employee when performing the radiological procedures. Transit dosimeters can be requested by email from the dosimetry service.

The dose results from the personal dosimeter and the transit dosimeter are reported separately in the usual manner. A correction for the transit dose can be made at the entrepreneur's request. The procedure regarding the correction for transit doses is available on request via [email protected].

Mirion Dosimetry Services has now been recognized by the Nuclear Safety and Radiation Protection Authority (ANVS) to use Instadose as a dose control agent. Work is currently underway to implement the Instadose in dose administration and further logistics.

No, unfortunately that is not possible. Our system provides one email address per employer and one email address per subscription group. The solution for this is to use our web application 'Dosimetry online'. You can then set that others are also given permission to view the dose data.

A returned dosimeter is always read and the results reported. However, experience has shown that the longer it takes for a dosimeter to be read (>6 months), the greater the uncertainty of the dose result will be.

You will receive a notification if we have not received the dosimeter back at the time of reporting. After three notifications, the dosimeter in question will be considered lost and replacement costs will be charged. Returning the relevant dosimeter does not entitle you to a refund of the amount charged.

Do you want a different dosimeter for the remaining time of the period? This can be sent within three working days. You have the option to open a new subscription via the website (for one period). If you do not want another dosimeter, please wait for your dosimeter for the new period.

In both cases, with or without a replacement dosimeter, a DNO message will be given on the dose report for the lost dosimeter. After three notifications, this message will disappear and you will receive an invoice for the replacement of the dosimeter.

Do you want a different dosimeter for the remaining time of the period? This can be sent within three working days. You have the option to open a new subscription yourself via the website. If you do not want another dosimeter, please wait for your dosimeter for the new period.

Put the broken dosimeter and any loose parts in a plastic bag with a note in the bag explaining what happened to the dosimeter.

If possible, the dosimeter will be read and the results reported to you in the usual manner. If the detectors in the dosimeter are too damaged or completely absent, this will unfortunately not work. We will then report this in the dose report via the message DNO (Dosimeter not received).

At this distance it is not possible to judge whether the dosimeter is still in order. Would you like a different dosimeter for the remaining time of the period? This can be sent within three working days. You have the option to open a new subscription yourself via the website. If you do not want another dosimeter, please wait for your dosimeter for the new period.

Return the “clean” dosimeter in a plastic bag with a note in the bag explaining what happened to the dosimeter.

If possible, the dosimeter will be read and the results reported to you in the usual manner. If the detectors in the dosimeter are too damaged, this will unfortunately not work. We will then report this in the dose report via the message DNO (Dosimeter not received).

You will receive a DNO message if there are no measurement data available from the relevant dosimeter at the time the dose report is created. If the dosimeter has now been sent, these results will be reported in the next dose report with the abbreviation NAG (subsequent report) in the details column. To prevent this situation in the future, it is recommended to return the used dosimeters soon after the arrival of the new dosimeters.

The abbreviations are stated on the dose report, to the right of the address. If the report relates to a different period than stated in the heading of the dose report, this is indicated in the details heading.

All depth doses, the personal dose equivalent at 10 mm depth, H_p(10), which are determined with personalized body dosimeters, are passed on to the NDRIS, the National Dose Registration and Information System. The doses determined with eyepiece dosimeters, ring dosimeters, space dosimeters and additional dosimeters are not included in the NDRIS.

On the NDIS site (www.NDRIS.nl) an application form 'Change dose data in the NDRIS' is included that specifies the describes the route taken. The procedure involves submitting a request for amendment addressed to the SZW Inspectorate, the former Labor Inspectorate.

On the NDRIS site (www.NDRIS.nl) an application form 'Report follow-up dose to NDRIS' has been included that describes the route to be taken. route describes.

The NDRIS website (www.NDRIS.nl) indicates how a request for a dose overview should be structured.

The NDRIS manager can issue a radiation passport at the request of an entrepreneur. A radiation passport can be requested via a form on the site www.NDRIS.nl, which can be found under the heading 'Request a radiation passport'. Under Dutch law, a radiation passport is not mandatory when carrying out actions at home or abroad.