The 13th International Conference on Environmental ... - Events

Abstracts
Onsite activities took place in up to 5 separate working areas including areas for post segmentation and packaging to
perform optimized parallel activities. All together about 85 tons of core internals where successfully dismantled at Stade
NPP until September ´09. To accomplish the best possible on-site performance and to achieve a minimization of the
applied collective dose rate, each onsite activity was previously planned in detail and personnel exercised each task at
original size mockups under most realistic onsite conditions. Planning was especially focused on an optimized size
minimization and packaging concept to reduce the number of filled waste packages. <strong>The</strong> segmentation of components
strictly followed a sophisticated cutting and packaging concept developed under consideration of possible cutting
techniques, the resulting geometry and logistical conditions. <strong>The</strong>refore segments were post processed by hydraulical
press and band saw in order to minimize their volume, were applicable.
2) 40102 – Study on evaluation models of management data for decommissioning of Fugen
Yuji Shibahara, Masanori Izumi, Takashi Nanko, Mitsuo Tachibana, Tsutomu Ishigami, JAEA (Japan)
In the Fugen nuclear power plant (FUGEN), the dismantling of equipments in the turbine building has started in
2008, and the dismantling of equipments around the reactor is scheduled around in 2015. To evaluate the management
data on this dismantling of equipments around reactor appropriately, it is very important to study whether the
conventional evaluation models have the applicability for FUGEN or not. Thus, the management data on the dismantling
of equipments in 3rd/4th feedwater heater room conducted in 2008 was calculated with the conventional evaluation
models. <strong>The</strong> conventional evaluation models were made by data obtained from Japan Power Demonstration Reactor
(JPDR) decommissioning program. It was found that there were large differences between the calculated values and the
actual data. For finding the cause in the difference between them, the dismantling of equipments in 3rd/4th feedwater
heater room was divided into three processes: i) the preparation process, ii) the dismantling process, and iii) the clean-up
process. In the both process of preparation and clean-up, the calculated values were smaller than the actual data. <strong>The</strong>se
were mostly caused by the plant scale difference between JPDR and FUGEN, because the conventional evaluation
models were built by analyzing the actual data on the decommissioning of JPDR which is smaller than FUGEN. <strong>The</strong>
primary expression depending on the area of working space was built as new evaluation models for the preparation and
clean-up processes. In the dismantling process, on the other hand, it was found that there were characteristic differences
in the dismantling of feedwater heater as follows: 1) the calculated values were significantly larger than the actual data,
2) the actual data for the dismantling of 3rd feedwater heater was larger than that of 4th one, though these equipments
were almost same weight. It was found that these were brought by the difference in the descriptions of dismantling of
feedwater heaters, and the new evaluation models reflecting the descriptions of dismantling were built for the appropriate
evaluation of the management data. <strong>The</strong> calculated values with the new evaluation models for each process showed the
good agreement with the actual data. In this report, study on evaluation models of management data for dismantling of
equipments in the feedwater heater room will be described.
3) 40083 – CORD Decontamination Technologies for Decommissioning - A Comprehensive Approach Based on
Over 30 Years Experience
Christoph Stiepani, AREVA NP GmbH (Germany)
Decontamination prior to Decommissioning and Dismantlement is imperative. Not only does it provide for
minimization of personnel dose exposure but also maximization of the material volume available for free release. Since
easier dismantling techniques in lower dose areas can be applied, the licensing process is facilitated and the scheduling
and budgeting effort is more reliable. <strong>The</strong> most internationally accepted approach for Decontamination prior to
Decommissioning projects is the Full System Decontamination (FSD). FSD is defined as the chemical decontamination
of the primary cooling circuit, in conjunction with the main auxiliary systems.
AREVA NP has long-term experience with Full System Decontamination for return to service of operating nuclear
power plants as well as for decommissioning after shutdown. Since 1976, AREVA NP has performed over 500
decontamination applications and, from 1986, AREVA NP has performed Decontaminations prior to Decommissioning
projects which comprise virtually all NPP designs and plant conditions:
- NPP designs: HPWR, PWR, and BWR by AREVA, Westinghouse, ABB and GE
- Decontaminations performed shortly after final shutdown or several years later, and even after re-opening Safe
Enclosure
- Gamma / Alpha inventory
- Main Coolant chemistry (e.g., with and without Zn injection during operation)
Fifteen Decontamination prior to Decommissioning Projects have been performed successfully to date. <strong>The</strong>
sixteenth FSD for Decommissioning at the French NPP Chooz A is now in the detailed engineering phase with onsite
application scheduled for Fall 2010.
This paper will describe the AREVA NP Decontamination Concept for Decommissioning (DCD) and present
highlights of previous FSDs performed prior to decommissioning using the CORD / AMDA technology.
4) 40007 – Chemical Decontamination for Decommissioning (DFD) and DFDX
Ronald Morris, Westinghouse Electric Company (USA)
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