1. The role of ALARA in management decisions
Jan Kops
NV KEMA, Arnhem the Netherlands
Two cases from the history of KEMA
The remediation of a dump site of radioactive waste on the KEMA premises.
The decommisioning of a nuclear test reactor (KSTR)

2. Background
In the fifties at KEMA a nuclear research program was started
The research was focussed on the development of a test reactor with a suspension of small (5 μm) spheres of mixed oxide (UO2/ThO2) in light water.
At that time, there were no regulations nor there was an organisation for the collection of radioactive waste. It was decided to bury the waste on the KEMA premises (untill the early seventies). In 1982 the site has been remediated.
A suspension test reactor (KSTR) was built and operated. The reactor has been decommissioned in two phases:
- the reactor installation: 1981 – 1991
- the remaining structures and buildings:

3. Site map of Business Park Arnhem

4. Remediation of the dump site
In the late seventies the site got nation-wide a lot of attention
The government:
- no objection against the site because of radiation risks
BUT
- the governmental policy is to remove dump sites which do not fulfil the environmental standards of today
- uncertainty about future developments on the KEMA site
remediate the dump site
KEMA: O.K., if it is assured that the waste can be removed permanently from the KEMA premises (last dumping in the deap ocean).

5. Remediation of the disposal site
The waste:
- the actually buried waste: 1344 drums of 90 litre
- soil: > 0,22 γBq/g considered as being contaminated
1400 m3 removed
38 m3 contaminated (cemented and dumped in 200 l drums)
- trees and trunks: all checked, none contaminated

6. Remediation of the disposal site
Radiation protection:
Basic principles:
no dispersion of radioactivity in the environment
+ a closed installation below atmospheric pressure (filtered ventilation)
+ measurements on 7 locations; no elevated levels found
doses of the workers: ALARA (or ALATA)
+ external exposure: no special measures (area monitoring)
collective dose: 0,35 mSv
+ internal contamination

7. Remediation of the disposal site
Radiation protection:
Basic principles:
no dispersion of radioactivity in the environment
- doses of the workers: ALARA (or ALATA)
+ external exposure
+ internal contamination: To be avoided totally
protective clothing with breath protection
continuous controll of airborne radioactivity
total body counting; urine analysis

8. Remediation of disposal site
Information of the public
- three info magazines
- an ‘open day’for the neighbours
- a weekly bulletin
- an info telephone line
- an information stand at the waste site
- an information video of the total operation

9. Map of the dumpholes made by a radiation protection technician during the dumping period

10. Drawing of the installation

13. Remediation of the waste site
Discussion and conclusions:
Total costs 5 million Euro (price level 2003)
No dispersion of activity in the environment
Negligable radiation exposure of the workers
No problems with pressure groups nor the public during the project and later
The leading factor in the decisions of the governmental as well as the KEMA management wasn’t ‘radiation protection’ but ‘publicity’
To avoid any negative publicity (at that time or later), in fact ALATA in stead of ALARA was applied

14. The decommissioning of the KEMA Suspension Test Reactor (KSTR

15. The KEMA Suspension Test Reactor
Built and operated in the period ;
Power: 1MWth;
Fuel: an aqueous suspension of 5μm UO2 / ThO2 spheres;
Total energy production: 150 MWh during a critical period of about two years.
What initially was thought to become a simple system (“A pot, a pipe and a pump”) turned out to be a very complex system

16. Decommisioning of the KSTR
Two phases:
First phase: Dismantling of the reactor system (1981 – 1991)
A demonstration and learning project
Second phase: Demolition of the building to green meadow (1999 –
2003)
The KEMA premises were transformed to ‘Business Park Arnhem’. The further development could be hindered by the residual nuclear facillities.

17. Conditions
First phase: reactor installation
- 6 interconnected complex subsystems
- narrow pipes, strongly contaminated with fision products and residual fuel
dose rates up to several mSv/hour
Second phase: Remaining structures and building
- reactor compartments (1 to 1,5 m thick walls of high quality concrete with 9 mm steel lining)
- walls and floors were significantly contaminated
- contaminated pipes embedded in the walls over long distances
- low radiation levels

18. Gas purification system
Reactor installation
Gas purification system
Reactor system
Dimensions 4,3 x 7 x 4 m3
Dimensions 4,3 x 4,3 x 8 m3

19. Remaining structures

20. Dismantling philosophy
First Phase
- Supervision by both an internal and external committee (with governmental officials);
- No reuse or unrestricted release of material from nuclear systems;
- Target for maximum cumulative dose (200 mSv);
Second phase
- Only a small internal advisory committee;
- Strict cost benefit considerations;
- Reuse or unrestricted release of as much material as possible;
- No dose targets but ALARA was embedded in the working procedures.

21. - As in the first project;
Radiation protection
First phase
- Film badge and TLD’s;
- Protective clothing and breath protection;
- Working area below atmospheric pressure;
- Continuous survey by a radiation protection technician.
Second phase
- As in the first project;
- Because of the relatively low radiation levels, less severe measures were needed;
- At the end, much attention was given to the release of the remaining building for conventional demolition (9 manmonths).

22. First phase: Dismantling of the reactor installation
A variety of segmentation techniques were developed or modified for remote handling
manipulator squeezers squeezed pipe

23. Second phase: Demolition of the building to green meadow
- Only on the market available techniques were used;
- Much was done manually

24. Results
First phase: Dismantling of the reactor installation
- 100 manyear during a 13 year period;
- 100 tons waste of which 80% radioactive waste;
- Collective dose: 115 mSv, far below the target (200 mSv);
Costs: 10 million (2003) Euros
Second phase: Demolition to green meadow
- project time 4 years;
tons of material removed, 99 % for reuse
- collective dose: 2,5 mSv
Costs: 3 million (2003) Euros

25. Conclusions (1)
In management decisions (mostly) ALARA is not involved, because a lot of aspects have to be considered, such as:
- future developments in politics and economy
- public relations / publicity

26. Conclusions (2)
Execution of projects
- Strong management support
(e.g. demonstration projects)
- Strong public and/or political concern
- Strict financial constraints, force to the real application of
ALARA (balancing of dose reduction and costs)
ALARA
tends to
ALATA