Decommissioning of Research Nuclear Reactor VVR-S Magurele –Bucharest
Analyzing, Justification and Selection of Decommissioning Strategy
M. Dragusin, V. Popa, A. Boicu, C. Tuca, I. Iorga, C. Mustata
National Institute of Physics and Nuclear Engineering-Magurele
The decommissioning of Research Nuclear Reactor VVR-S Magurele –Bucharest involves the removal of the
radioactive and hazardous materials to permit the facility to be released without representing a further risk to human
health and the environment. A very important aspect of decommissioning is analyzing, justification and selection of
decommissioning strategy. There are in study two strategies: DECON (Immediate Dismantling) and SAFSTOR (Safe
Enclosure).
Decommissioning project of VVR-S Research Reactor has been developed in accordance with IAEA
documents in three stages:
Decommissioning of VVR-S nuclear reactor, will be realised by a process which containes three succesive
stages. This process coresponds to the method described by NRC as DECON immediat decommissioning after the end
of authorised preservation period.
We notice that:
 The shut-down moment of WWR-S Nuclear Reactor was in 1997,
 Time of decommissioning for completing 1 and 2 stages is estimated at 5 years,
 The beginning of the stage 3 decommissioning activities will take place after minimum 12 years period since the
shut-down of the reactor, a similar effect with the maintaining period
DECON Stage 1 (2004- half 2006)
Stage 1 will preserve the operationally of all reactor buildings and systems, are focusing on the evacuation
from the site of the materials, equipment and non-nuclear structures having a foreseen minor effect on the subsequent
decom stages.
DECON Stage 2 (half 2006-2008)
Stage 2 includes the bulk of the substantive decommissioning operations - decontamination, dismantling,
demolition, treatment, conditioning, off-site evacuation and disposal of radioactive waste – and the erection of the
Secured Containment Volume for the coming hold-up period. A basic prerequisite for the initiation of Stage 2 is that
all nuclear fuel is completely evacuated from the reactor house. Requisite conditions regard the full operability of
the decom-related working facilities, especially the Radioactive Waste Treatment Station, Spent Fuel Storage Facility,
and Hot Cells for possible recanting of spent fuel.
DECON Stage 3 (2009 - 2019)
At the end of the hold-up time, Stage 3 DECON may be initiated based on a specific authorization by the
Regulatory Authority. The basic prerequisite for proceeding to Decommissioning Stage 3 is that a full radiological
characterization of the site ascertains that the procedure is safe, and feasible in conformity with the norms in effect
at that time.
The Final Picture.
On completion of the ecological reconstruction, what may eventually remain from the current reactor
compound is the laboratory building that may be retrofit into a “clean” research facility. In consideration of the
demolition work-taking place in the area as described (v. the reactor house), an appropriate architectural and structural
engineering solution should be identified and implemented.
References:
1.Decommissioning Handbook, DOE/EM-383, 2000, SUA
2.Decommissioning Handbook, DOE/EM-0142P, 1994, SUA
3. Legea nr. 111/96/rep98, legea 193/2003, Norme CNCAN in domeniul nuclear
4. Decommissioning Plan of VVR-S Reactor, 2002-2003
Comparation between option 1 and option 2:
Option1: Defueling, draining and maintenance
Option 2: Immediate dismantling
Factor
Option 1
Option 2
Geographical
Location
The site is placed in “Campia Romana” between rivers Sabar and Dambovita at about 3 km South – West from built limit of city Bucharest and 8 km right
line from town center, at distances 0.8 km, 1.2 km, and 5 km from rivers Ciorogarla, Sabar and Arges respectively in direction South-South-West. Group
I, part of the National Institute for Physic and Nuclear Engineering, where the “VVR-S Nuclear Reactor” is located at about 1km from village Magurele;
Infrastructure
of the specific
site and
facilities
Future use of
site and
facilities
Waste routes
The Group I precincts are connected to highway Bucharest – Magurele by a lateral asphalt road of 1 km length and a joint of 0.8 km of belt railway.
Around Group I precincts on radius of about 800 m there is an affronted zone and constitutes an exclusion and sanitary protection zone. The site is
provided with facilities and installations,and they include service ducts (2.20m X 1.80m) which in their turn, contain the cool water piping, service
cooling water piping, thermal piping, compressed air piping and the power cable routes.
Building and site environmental restoration
Building and site Ecological restoration and their reutilization in short time
Available
Generally available but additional facilities would be needed for size reduction
and for packaging of large individual component
Waste
quantities
Plant
knowledge and
exposure
Minimum decommisioning waste
Large quantities of decom. waste
Maintenance team needed and relevant knowledge experience
should be retained, relating to the wide range of remaining systems
for future decommissioning planning and implementation.
Use personnel with experience from Reactor, we expect high exposure (collective
dose) which implies an appropriate radioprotection system
Technology
Part of necessary tasks can be performed with existing staff,
working under existing operational methods and procedures.
Decontamination and dismantling technologies must be applied. More waste
packaging and transport techno-logies are needed, composed with normal
operations. Robotics and new storage technologies are needed, too.
Training
No additional training required, but after a long period we need a
personnel which have to be trained (cost of money)
Least possible initial founding requirement. Substantial maintenance
and surveillance founds needed through the deferral period
Appropriate decommissioning training required.
No additional regulatory framework required
Appropriate regulatory framework needed, but is not yet in plane.
The reactor building should not withstand a sessions plane crash,
explosion or fire. Major damage from earthquakes can not be
excluded. The reactor building can not be considered as an effective
long term secondary containment. Consequently the speed of
significant quantities of radioactivity must be regard as possible
hazard.
Subject to confirmation by structural specialists the reactor block is likely to be
adequately resistant to external events. Since all significant radioactivity is safely
enclosed inside the reactor block, a possible collapse of the reactor building would
not lead to a spent of radioactivity. Hazards can happen from accidental mistakes
of the workers, a very good training will minimize them. Possible accidents or
incidents will be analyzed and required measures will be taken, as well as other
protection measures for preventing possible hazards.
Founds
Regulatory
Aspects
Hazards
Substantial founds needed for the decommissioning tasks. For a low maintenance
and surveillance, for new technologies and instruments, for safety work needed
are founds necessary.