# Development of PACTITER code and its application to safety analyses of ITER Primary Cooling Water System

Luigi Di Pace, Frédéric Dacquait, Frédéric Nguyen, Bertrand Larat

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Luigi Di Pace, Frédéric Dacquait, Frédéric Nguyen, Bertrand Larat. Development of PACTITER code and its application to safety analyses of ITER Primary Cooling Water System. EUROCORR 2005 - The European Corrosion Congress Book of Abstracts, Lisbonne, Portugal, 4-8 September 2005, Sep 2005, Lisbonne, Portugal. cea-04464346

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# Development of PACTITER code and its application to safety analyses of ITER Primary Cooling Water System

Luigi Di Pace, Frédéric Dacquait, Frédéric Nguyen, Bertrand Larat

► To cite this version:

Luigi Di Pace, Frédéric Dacquait, Frédéric Nguyen, Bertrand Larat. Development of PACTITER code and its application to safety analyses of ITER Primary Cooling Water System. EUROCORR 2005 - The European Corrosion Congress Book of Abstracts, Lisbonne, Portugal, 4-8 September 2005, Sep 2005, Lisbonne, Portugal. cea-04464346

HAL Id: cea-04464346

https://cea.hal.science/cea-04464346v1

Submitted on 18 Feb 2024

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
# Development of PACTITER code and its application to safety analyses of ITER Primary Cooling Water System

L. Di Pace<sup>a</sup>, F. Dacquait<sup>b</sup>, F. Nguyen<sup>b</sup>, B. Larat<sup>b</sup>

<sup>a</sup> Associazione Euratom-ENEA sulla Fusione, Via Enrico Fermi 45, 00044 Frascati, Italy,
<sub>di pace@frascati.enea.it</sub>

<sup>b</sup>CEA/DEN, Cadarache, 13108 St Paul lez Durance Cedex France, <sub>frederic.dacquait@cea.fr</sub>

## Abstract

The PACTITER code derives from the PACTOLE code, developed by the CEA for predicting Activated Corrosion Products (ACPs) in PWR primary circuits. The PACTOLE code was initially used (1994-1997) for predicting ACPs in the various stainless steel based Primary Heat Transfer System (PHTS) loop of the International Thermonuclear Experimental Reactor (ITER). The operating conditions, material compositions and water chemistry of ITER PHTS (no soluble Boron, lower temperature range (100-240°C), and mainly the presence of Cu-alloy in the divertor cooling loop) made mandatory the development of a dedicated code. Required chemical data were provided by “ad hoc” experimental tests, carried out at CEA Fontenay-aux-Rose (1997) and aimed to derive Cu solubility law in ITER relevant conditions. The application of such new code, named PACTITER, to divertor cooling loop was promising, as the predicted Cu-alloy release rates were in agreement with experimental data. The PACTITER code was then applied to predict the ACP source term for all ITER EDA (1998) PHTS cooling loops: first-wall/blanket (10 loops), limiter/baffle (4 loops), divertor (4 loops) and vacuum vessel (2 loops). The ACP inventory and its distribution on loop components, predicted by the code, were used as input for the accident analyses related to LOCA and to foresee the collective dose to the staff involved in scheduled and unscheduled maintenance. Related results were documented in the ITER NSSR-2 (Non-Site Specific Safety Report 2). Following the evolution of the ITER design (2001) to a reduced-cost machine, the PHTS was completely redesigned with a drastic reduction of number of loops: 3 for the primary first wall/blanket, 1 for the divertor/limiter and 2 for the vacuum vessel. The PACTITER code was again used in support of accident analysis and worker collective dose assessment, with results documented in the Generic Site Safety Report (GSSR) (2001). Pending the final decision for the ITER site, in order to improve the validation level of PACTITER, tests were performed by CEA in 2001 and 2004 in the CORELE test facility. The comparison between experimental results and PACTITER predictions has provided good results, revealing the influence of the Reynolds on the material release rate.

A new version of PACTOLE (version 3) has been designed to account for recent development relevant to the behaviour of corrosion products: improvement of the corrosion/release model, of the oxide and equilibrium concentration determination. Moreover, the data processing architecture and the numerical analysis for solving transient equations have been totally reviewed. It is foreseen that the PACTITER code will profit by these improvements.

**Keywords:** ITER, safety analysis, ACPs, PACTITER, PACTOLE

## 1 Introduction

The PACTITER (Prediction of ACTivation for ITER) code was originally developed with the name of PACTOLE [1] at the Commissariat à l'Energie Atomique (CEA) Centre de Cadarache, to predict the formation, activation, migration and deposition of corrosion products in the PWR primary cooling loop. The other main purpose of the code application is
# Development of PACTITER code and its application to safety analyses of ITER Primary Cooling Water System

L. Di Pace<sup>a</sup>, F. Dacquait<sup>b</sup>, F. Nguyen<sup>b</sup>, B. Larat<sup>b</sup>

<sup>a</sup> Associazione Euratom-ENEA sulla Fusione, Via Enrico Fermi 45, 00044 Frascati, Italy,
<sup>b</sup> CEA/DEN, Cadarache, 13108 St Paul lez Durance Cedex France, [frederic.dacquait@cea.fr](mailto:frederic.dacquait@cea.fr)

## Abstract

The PACTITER code derives from the PACTOLE code, developed by the CEA for predicting Activated Corrosion Products (ACPs) in PWR primary circuits. The PACTOLE code was initially used (1994-1997) for predicting ACPs in the various stainless steel based Primary Heat Transfer System (PHTS) loop of the International Thermonuclear Experimental Reactor (ITER). The operating conditions, material compositions and water chemistry of ITER PHTS (no soluble Boron, lower temperature range (100-240°C), and mainly the presence of Cu-alloy in the divertor cooling loop) made mandatory the development of a dedicated code. Required chemical data were provided by “ad hoc” experimental tests, carried out at CEA Fontenay-aux-Rose (1997) and aimed to derive Cu solubility law in ITER relevant conditions. The application of such new code, named PACTITER, to divertor cooling loop was promising, as the predicted Cu-alloy release rates were in agreement with experimental data. The PACTITER code was then applied to predict the ACP source term for all ITER EDA (1998) PHTS cooling loops: first-wall/blanket (10 loops), limiter/baffle (4 loops), divertor (4 loops) and vacuum vessel (2 loops). The ACP inventory and its distribution on loop components, predicted by the code, were used as input for the accident analyses related to LOCA and to foresee the collective dose to the staff involved in scheduled and unscheduled maintenance. Related results were documented in the ITER NSSR-2 (Non-Site Specific Safety Report 2). Following the evolution of the ITER design (2001) to a reduced-cost machine, the PHTS was completely redesigned with a drastic reduction of number of loops: 3 for the primary first wall/blanket, 1 for the divertor/limiter and 2 for the vacuum vessel. The PACTITER code was again used in support of accident analysis and worker collective dose assessment, with results documented in the Generic Site Safety Report (GSSR) (2001). Pending the final decision for the ITER site, in order to improve the validation level of PACTITER, tests were performed by CEA in 2001 and 2004 in the CORELE test facility. The comparison between experimental results and PACTITER predictions has provided good results, revealing the influence of the Reynolds on the material release rate.

A new version of PACTOLE (version 3) has been designed to account for recent development relevant to the behaviour of corrosion products: improvement of the corrosion/release model, of the oxide and equilibrium concentration determination. Moreover, the data processing architecture and the numerical analysis for solving transient equations have been totally reviewed. It is foreseen that the PACTITER code will profit by these improvements.

**Keywords:** ITER, safety analysis, ACPs, PACTITER, PACTOLE

## 1 Introduction

The PACTITER (Prediction of ACTivation for ITER) code was originally developed with the name of PACTOLE [1] at the Commissariat à l'Energie Atomique (CEA) Centre de Cadarache, to predict the formation, activation, migration and deposition of corrosion products in the PWR primary cooling loop. The other main purpose of the code application is
estimating the effects of changes in design and operating parameters. The PACTOLE code
has been validated by comparison between simulation and more than 20 years of
measurements on French PWRs.

## 2 PACTOLE/PACTITER phenomenological model description

According to the models used in version 2 of PACTOLE/PACTITER, the main driving force of base metal release, dissolution and precipitation is the concentration gradient between the surface and the bulk coolant. It is further assumed that the concentration for each element at the pipe wall is very close to its solubility in the same conditions. A deposited element can be dissolved if the element concentration in the bulk water is below the solubility value. When the coolant becomes supersaturated in corrosion products, ions can precipitate on the walls or in the bulk of the fluid to form particles. Equilibrium concentrations are derived from thermodynamic laws and depend on temperature and water chemistry (pH, hydrogen partial pressure). It should be kept in mind that chemical data for PACTOLE are fitted for a reducing environment, i.e. excess concentrations of H₂ are used to prevent radiolysis. This results in very low level of O₂ (< 20 ppb) in the cooling fluid. Precipitates agglomerate by collision to form particles and their size increases up to the limit dependent on degree of turbulence. The agglomerated particles are carried away by the coolant by convection and transported to the wall by mass diffusion. Deposits formed in this way are under the influence of shear stresses from flowing coolant and in some cases release by erosion can occur. Activation occurs when ions and deposits are subjected to neutron flux. On the other hand, the corrosion of structural materials under neutron flux is accompanied by a release of radioactive corrosion products. In addition, the active nuclides (ions and particles) after transportation by the coolant and deposition diffuse inside the oxide layers and contaminate them.

## 3 Application of PACTOLE to ITER: the development of the PACTITER code

The PACTOLE code is currently being used under the name of PACTITER for predicting the Activated Corrosion Product (ACP) inventory in the various ITER (International Thermonuclear Experimental Reactor) heat transfer system (HTS) circuits for accident analysis and personnel safety (ORE assessment).

At the beginning (1994-1996), the PACTOLE code was adapted as far as the input deck was concerned to the ITER case for predicting activated corrosion products inventory and distribution in the Primary Heat Transfer System (PHTS) of the ITER TCWS (Tokamak Cooling Water System) [2, 3]. The major modifications were aimed to simulate the particular ITER PHTS operating conditions, which are quite different from those of PWRs. In PWRs, the coordinated B-Li chemistry is used to control a constant pH₃₀₀ °C to a target value of 7.2 characterized by the use of boric acid (H₃BO₃) and Li hydroxide (LiOH) differently from ITER PHTS where only pH and H₂ content are defined. The other main difference is the temperature range, which is 100-240 °C for ITER operation.

The other peculiarity of the ITER PHTS is the presence of copper alloys cooled down by pressurized water in the divertor cooling loops. That required adapting the PACTOLE V2 code to consider the new element Cu. Since PACTOLE V2 deals with six chemical elements (Fe, Ni, Mn, Cr, Co and Zr) and ten corresponding isotopes, the introduction of copper into the code required the replacement of Zr by Cu and the addition of related chemical and radiochemical data. The PACTOLE V2 code, incorporating Cu by replacing Zr, was named after as PACTITER V1 and made available in early 1996. It adopted a Cu solubility curve assuming the Cu surface was Cu oxide. This proved to have been an optimistic assumption. These data were obtained by a survey work of the existing literature [4] and incorporated into the code by CEA Cadarache. The code was then used by ENEA Frascati for its work
estimating the effects of changes in design and operating parameters. The PACTOLE code
has been validated by comparison between simulation and more than 20 years of
measurements on French PWRs.

## 2 PACTOLE/PACTITER phenomenological model description

According to the models used in version 2 of PACTOLE/PACTITER, the main driving force of base metal release, dissolution and precipitation is the concentration gradient between the surface and the bulk coolant. It is further assumed that the concentration for each element at the pipe wall is very close to its solubility in the same conditions. A deposited element can be dissolved if the element concentration in the bulk water is below the solubility value. When the coolant becomes supersaturated in corrosion products, ions can precipitate on the walls or in the bulk of the fluid to form particles. Equilibrium concentrations are derived from thermodynamic laws and depend on temperature and water chemistry (pH, hydrogen partial pressure). It should be kept in mind that chemical data for PACTOLE are fitted for a reducing environment, i.e. excess concentrations of H₂ are used to prevent radiolysis. This results in very low level of O₂ (< 20 ppb) in the cooling fluid. Precipitates agglomerate by collision to form particles and their size increases up to the limit dependent on degree of turbulence. The agglomerated particles are carried away by the coolant by convection and transported to the wall by mass diffusion. Deposits formed in this way are under the influence of shear stresses from flowing coolant and in some cases release by erosion can occur. Activation occurs when ions and deposits are subjected to neutron flux. On the other hand, the corrosion of structural materials under neutron flux is accompanied by a release of radioactive corrosion products. In addition, the active nuclides (ions and particles) after transportation by the coolant and deposition diffuse inside the oxide layers and contaminate them.

## 3 Application of PACTOLE to ITER: the development of the PACTITER code

The PACTOLE code is currently being used under the name of PACTITER for predicting the Activated Corrosion Product (ACP) inventory in the various ITER (International Thermonuclear Experimental Reactor) heat transfer system (HTS) circuits for accident analysis and personnel safety (ORE assessment).

At the beginning (1994-1996), the PACTOLE code was adapted as far as the input deck was concerned to the ITER case for predicting activated corrosion products inventory and distribution in the Primary Heat Transfer System (PHTS) of the ITER TCWS (Tokamak Cooling Water System) [2, 3]. The major modifications were aimed to simulate the particular ITER PHTS operating conditions, which are quite different from those of PWRs. In PWRs, the coordinated B-Li chemistry is used to control a constant pH₃₀₀ °C to a target value of 7.2 characterized by the use of boric acid (H₃BO₃) and Li hydroxide (LiOH) differently from ITER PHTS where only pH and H₂ content are defined. The other main difference is the temperature range, which is 100-240 °C for ITER operation.

The other peculiarity of the ITER PHTS is the presence of copper alloys cooled down by pressurized water in the divertor cooling loops. That required adapting the PACTOLE V2 code to consider the new element Cu. Since PACTOLE V2 deals with six chemical elements (Fe, Ni, Mn, Cr, Co and Zr) and ten corresponding isotopes, the introduction of copper into the code required the replacement of Zr by Cu and the addition of related chemical and radiochemical data. The PACTOLE V2 code, incorporating Cu by replacing Zr, was named after as PACTITER V1 and made available in early 1996. It adopted a Cu solubility curve assuming the Cu surface was Cu oxide. This proved to have been an optimistic assumption. These data were obtained by a survey work of the existing literature [4] and incorporated into the code by CEA Cadarache. The code was then used by ENEA Frascati for its work
supporting ITER NSSR-1 (Non-Site Specific Safety Report n.1) in late 1996. The results obtained were considered highly preliminary.

In parallel an experimental campaign, performed by CEA Fontenay-aux-Roses, was launched in early 1996 to get Cu solubility data in the ITER divertor PHTS conditions [5]. This experimental study was devoted to determine the valence states of the copper (Cu⁰, Cu⁺ or Cu⁺⁺) and to obtain solubility in steady state conditions. In order to check the stable phases of Cu in ITER divertor coolant conditions, autoclave tests were performed on copper and copper oxides. These included four tests at 100 and 250 °C on CuO and Cu₂O, pure copper and Cu-Cr-Zr (the reference Cu alloy for ITER divertor high heat flux components).

The major findings of this part of the study were:

* In reducing conditions, stable phase is Cu⁰, dissolution can occur according to the chemical reaction:

$$Cu^{0}_{(s)} + H^{+}_{(aq)} \rightleftharpoons Cu^{+}_{(aq)} + 1/2 H_{2(g)};$$

* Kinetics of reduction from Cu¹ and/or Cu¹¹ to Cu⁰ is very slow.

The other part of the experimental campaign was devoted to determine the total concentration of soluble copper in equilibrium with Cu-Cr-Zr alloy in chemical conditions close to those of the ITER divertor primary coolant. The solubility measurements were carried out in a flow device made of titanium. The measured pH during all the tests was in the range of 6.4 ±0.2.

The related values, illustrated in Figure 1 [6], are quite different from those adopted first in PACTITER V1 and coming from literature [4].

<figure><img src="image_2.png" /><figcaption>Figure 1- Cu concentration in steady state conditions, comparison of experiments data [5] and literature data [4]</figcaption></figure>

The copper concentrations determined by tests are four or five orders of magnitude larger than the copper solubility obtained by thermodynamic data.

Such difference could be explained by:

* the validity of thermodynamic data (See Appendix of [1]);

* the formation of copper colloids during tests;

* the presence of another Cu species, such as copper oxides previously formed during the exposure to vapours at room temperature or before establishing reducing conditions;

* the oxidation of Cu due to the existence of oxygen traces in water (copper is known as a very good getter of oxygen).

In conclusion, it is possible to state that solubility measured during the tests is questionable.
supporting ITER NSSR-1 (Non-Site Specific Safety Report n.1) in late 1996. The results obtained were considered highly preliminary.

In parallel an experimental campaign, performed by CEA Fontenay-aux-Roses, was launched in early 1996 to get Cu solubility data in the ITER divertor PHTS conditions [5]. This experimental study was devoted to determine the valence states of the copper (Cu⁰, Cu⁺ or Cu⁺⁺) and to obtain solubility in steady state conditions. In order to check the stable phases of Cu in ITER divertor coolant conditions, autoclave tests were performed on copper and copper oxides. These included four tests at 100 and 250 °C on CuO and Cu₂O, pure copper and Cu-Cr-Zr (the reference Cu alloy for ITER divertor high heat flux components).

The major findings of this part of the study were:

* In reducing conditions, stable phase is Cu⁰, dissolution can occur according to the chemical reaction:

$$Cu^{0}_{(s)} + H^{+}_{(aq)} \rightleftharpoons Cu^{+}_{(aq)} + 1/2 H_{2(g)};$$

* Kinetics of reduction from Cu¹ and/or Cu¹¹ to Cu⁰ is very slow.

The other part of the experimental campaign was devoted to determine the total concentration of soluble copper in equilibrium with Cu-Cr-Zr alloy in chemical conditions close to those of the ITER divertor primary coolant. The solubility measurements were carried out in a flow device made of titanium. The measured pH during all the tests was in the range of 6.4 ±0.2.

The related values, illustrated in Figure 1 [6], are quite different from those adopted first in PACTITER V1 and coming from literature [4].

<figure><img src="image_2.png" /><figcaption>Figure 1- Cu concentration in steady state conditions, comparison of experiments data [5] and literature data [4]</figcaption></figure>

The copper concentrations determined by tests are four or five orders of magnitude larger than the copper solubility obtained by thermodynamic data.

Such difference could be explained by:

* the validity of thermodynamic data (See Appendix of [1]);

* the formation of copper colloids during tests;

* the presence of another Cu species, such as copper oxides previously formed during the exposure to vapours at room temperature or before establishing reducing conditions;

* the oxidation of Cu due to the existence of oxygen traces in water (copper is known as a very good getter of oxygen).

In conclusion, it is possible to state that solubility measured during the tests is questionable.
The new release of the code PACTITER, known as PACTITER V2, incorporating the experimental Cu data was ready in late 1997. It was also updated from the radiochemical viewpoint, to take into account the major radionuclides produced by the copper activation. The three following nuclear reactions involving Cu, found to be the most important ones for safety analysis, were included in PACTITER V2:

- $^{63}\text{Cu}(n, \gamma)^{64}\text{Cu}$;

- $^{65}\text{Cu}(n, 2n)^{64}\text{Cu}$;

- $^{63}\text{Cu}(n, \alpha)^{60}\text{Co}$.

Using the new tool PACTITER V2, the ACP assessment for all ITER cooling loops were completed in early 1998 in support to NSSR-2, Volume III “Radiological and Energy Source Terms”. The ACP assessment was then repeated to take into account design modification in the PHTS design (e.g. the heat exchangers with primary coolant on the shell side) [7]. The comparison with experimental corrosion data related to ITER operating conditions and Cu-alloys provided a satisfactory result [6].

Further to the decision taken to update the ITER Final Design Report defined in 1998 (ITER FDR) to reduce size and cost of the machine still satisfying the overall programmatic objective of the ITER EDA Agreement, the machine design was reviewed including that of PHTS during the extension (1998-2001) of the EDA (Engineering Design Activity) phase. The number of cooling loops of the PHTS was reduced from a total of 20 to 6. Again, the code PACTITER V2 was again applied to estimate the ACP inventory of the ITER PHTS according to the new design in support of accident analysis and worker collective dose assessment, with results documented in the Generic Site Safety Report (GSSR) [8].

## 4 ITER PHTS design evolution

Since the first application of the PACTOLE code to assess the ACPs inventory in ITER, the design of the PHTS has evolved along with the other modifications. In Table 1, it is presented the major modifications to ITER PHTS design since 1995.

In Figure 2, the ITER PHTS is schematized according to the FDR 1998, together with the PACTITER geometric model of one of the ten loops of the FW/shield/Inboard baffle PHTS.

<table><caption>Table 1 – ITER PHTS design evolution</caption><thead><tr><th>Year</th><th>ITER Design Evolution</th><th>ITER Thermal Power removed by PHTS [MW]</th><th>Total number of loops</th><th>divided in</th></tr></thead><tbody><tr><td>1995</td><td>Draft IDR</td><td>2325</td><td>10</td><td>4 for DIV, 4 for FW/SB, 2 for VV</td></tr><tr><td>1996</td><td>IDR</td><td>2413</td><td>20</td><td>4 for DIV, 10 for FW/shield/IBB, 4 for Lim/OBB, 2 for VV</td></tr><tr><td>1998</td><td>FDR</td><td colspan="3">Same as IDR but using the HX tube side for secondary side</td></tr><tr><td>2001</td><td>FDR</td><td>932</td><td>6</td><td>3 for FW/Sh, 1 for DIV, 2 for VV</td></tr></tbody></table>

Note: IDR = Interim Design Report; FDR = Final Design Report; DIV = Divertor; FW/SB = First Wall/Shielding Blanket; VV = Vacuum Vessel; FW/shield/IBB = First Wall/Shield/InBoard Blanket; Lim/OBB = Limiter/OutBoard Baffle; FW/Sh = First Wall/Shield
The new release of the code PACTITER, known as PACTITER V2, incorporating the experimental Cu data was ready in late 1997. It was also updated from the radiochemical viewpoint, to take into account the major radionuclides produced by the copper activation. The three following nuclear reactions involving Cu, found to be the most important ones for safety analysis, were included in PACTITER V2:

- $^{63}\text{Cu}(n, \gamma)^{64}\text{Cu}$;

- $^{65}\text{Cu}(n, 2n)^{64}\text{Cu}$;

- $^{63}\text{Cu}(n, \alpha)^{60}\text{Co}$.

Using the new tool PACTITER V2, the ACP assessment for all ITER cooling loops were completed in early 1998 in support to NSSR-2, Volume III “Radiological and Energy Source Terms”. The ACP assessment was then repeated to take into account design modification in the PHTS design (e.g. the heat exchangers with primary coolant on the shell side) [7]. The comparison with experimental corrosion data related to ITER operating conditions and Cu-alloys provided a satisfactory result [6].

Further to the decision taken to update the ITER Final Design Report defined in 1998 (ITER FDR) to reduce size and cost of the machine still satisfying the overall programmatic objective of the ITER EDA Agreement, the machine design was reviewed including that of PHTS during the extension (1998-2001) of the EDA (Engineering Design Activity) phase. The number of cooling loops of the PHTS was reduced from a total of 20 to 6. Again, the code PACTITER V2 was again applied to estimate the ACP inventory of the ITER PHTS according to the new design in support of accident analysis and worker collective dose assessment, with results documented in the Generic Site Safety Report (GSSR) [8].

## 4 ITER PHTS design evolution

Since the first application of the PACTOLE code to assess the ACPs inventory in ITER, the design of the PHTS has evolved along with the other modifications. In Table 1, it is presented the major modifications to ITER PHTS design since 1995.

In Figure 2, the ITER PHTS is schematized according to the FDR 1998, together with the PACTITER geometric model of one of the ten loops of the FW/shield/Inboard baffle PHTS.

<table><caption>Table 1 – ITER PHTS design evolution</caption><thead><tr><th>Year</th><th>ITER Design Evolution</th><th>ITER Thermal Power removed by PHTS [MW]</th><th>Total number of loops</th><th>divided in</th></tr></thead><tbody><tr><td>1995</td><td>Draft IDR</td><td>2325</td><td>10</td><td>4 for DIV, 4 for FW/SB, 2 for VV</td></tr><tr><td>1996</td><td>IDR</td><td>2413</td><td>20</td><td>4 for DIV, 10 for FW/shield/IBB, 4 for Lim/OBB, 2 for VV</td></tr><tr><td>1998</td><td>FDR</td><td colspan="3">Same as IDR but using the HX tube side for secondary side</td></tr><tr><td>2001</td><td>FDR</td><td>932</td><td>6</td><td>3 for FW/Sh, 1 for DIV, 2 for VV</td></tr></tbody></table>

Note: IDR = Interim Design Report; FDR = Final Design Report; DIV = Divertor; FW/SB = First Wall/Shielding Blanket; VV = Vacuum Vessel; FW/shield/IBB = First Wall/Shield/InBoard Blanket; Lim/OBB = Limiter/OutBoard Baffle; FW/Sh = First Wall/Shield
<figure><img src="image_3.png" /><figcaption>Figure 2 - ITER Primary Heat Transfer System (FDR 1998) and PACTITER geometric model of one PHTS loop of the FW/shield/Inboard baffle</figcaption></figure>

## 5 ITER safety requirements for ACPs

ACPs will be present in ITER in the various in-vessel and vacuum vessel coolant loops as well as in any coolant loops related to test modules, auxiliary heating or diagnostics equipment. These products impact occupational exposure, routine effluents to the environment, and potential releases during accidents. That has made the ACP inventory evaluation an important task for ITER public and occupational safety. ACPs present in fission reactors cooling loops do not pose a significant public hazard in these installations, while they are a significant hazard to site personnel. In fact, in case of severe accidents in LWRs, ACPs are negligible in terms of radioactive inventory (RI), mobilisable inventory (MI) and environmental source term (EST), compared to the analogous inventories from the reactor core (gas and fission products). On the contrary for fusion devices such as ITER, ACPs could be not negligible in terms of the whole mobilisable inventory (MI) in case of accidents compared to other major source terms, tritium and dust.

The enveloping ACPs inventory adopted for ITER accident analyses [9] was assumed to be 10 kg/loop as deposit and 0.6% of deposit mass in the suspended forms (soluble ions or crud particulates), irrespective of the cooling loop type, FW/shield, divertor or vacuum vessel.
<figure><img src="image_3.png" /><figcaption>Figure 2 - ITER Primary Heat Transfer System (FDR 1998) and PACTITER geometric model of one PHTS loop of the FW/shield/Inboard baffle</figcaption></figure>

## 5 ITER safety requirements for ACPs

ACPs will be present in ITER in the various in-vessel and vacuum vessel coolant loops as well as in any coolant loops related to test modules, auxiliary heating or diagnostics equipment. These products impact occupational exposure, routine effluents to the environment, and potential releases during accidents. That has made the ACP inventory evaluation an important task for ITER public and occupational safety. ACPs present in fission reactors cooling loops do not pose a significant public hazard in these installations, while they are a significant hazard to site personnel. In fact, in case of severe accidents in LWRs, ACPs are negligible in terms of radioactive inventory (RI), mobilisable inventory (MI) and environmental source term (EST), compared to the analogous inventories from the reactor core (gas and fission products). On the contrary for fusion devices such as ITER, ACPs could be not negligible in terms of the whole mobilisable inventory (MI) in case of accidents compared to other major source terms, tritium and dust.

The enveloping ACPs inventory adopted for ITER accident analyses [9] was assumed to be 10 kg/loop as deposit and 0.6% of deposit mass in the suspended forms (soluble ions or crud particulates), irrespective of the cooling loop type, FW/shield, divertor or vacuum vessel.
The other important safety requirements are the project release guidelines for the ACPs, tritium and dusts as shown in Table 2.

<table><caption>Table 2 - Project Release Guidelines [10]</caption><thead><tr><th>Events or Conditions</th><th>Project Release Guideline(*)</th></tr></thead><tbody><tr><td><strong>Normal Operation</strong><br>event sequences and plant conditions planned and required for ITER normal operation, including some faults, events or conditions which can occur as a result of the ITER experimental nature</td><td>&lt; 1 g-T as HT and 0.1g-T as HTO and 1 g-metal as AP and <strong>5 g-metal as ACP per year</strong>.</td></tr><tr><td><strong>Incidents</strong><br>deviations from normal operation, event sequences or plant conditions not planned but likely to occur due to failures one or more times during the life of the plant but not including Normal Operation</td><td>&lt; 1 g-T as HT or 0.1 g-T as HTO or 1 g-metal as AP or <strong>1 g-metal as ACP</strong> or equivalent combination of these per event</td></tr><tr><td><strong>Accidents</strong><br>postulated event sequences or conditions not likely to occur during the life of the plant.</td><td>&lt; 50 g-T as HT or 5 g-T as HTO or 50 g-metal as AP or <strong>50 g-metal as ACP</strong> or equivalent combination of these per event.</td></tr></tbody></table>

Note: (*) HT: elemental tritium (including DT); HTO: tritium oxide (includingDTO); AP: divertor or first-wall activation products; ACP: activated corrosion products.

For the occupational radiation exposure (ORE) doses, the following limits and project guidelines have been adopted [10] as shown in Table 3.

<table><caption>Table 3 – ITER limits and project guidelines for ORE doses</caption><thead><tr><th colspan="2">Dose Limits</th></tr></thead><tbody><tr><td>ICRP recommended limit for annual<br>individual worker doses</td><td>20 mSv averaged over 5 years not to exceed<br>50 mSv in any year</td></tr><tr><th colspan="2">Project Guidelines</th></tr><tr><td>Annual individual worker doses</td><td>5 mSv/year</td></tr><tr><td>Individual worker dose for any given shift</td><td>0.5 mSv/shift</td></tr></tbody></table>

## 6 Results of ITER ACP assessment by PACTITER

As written in section 3, many calculations were carried out with the PACTOLE code first and then with the PACTITER code to assess ACP in the PHTS of ITER TCWS, following the several evolutions of the design. In this section the results presented are referred to the latest evolution of the design as and they are fully documented in the related official technical document [8]. The ACP assessment carried out for a single First Wall/Shield cooling loop provided a value of 1.8 g of suspended cruds and 10.9 g of dissolved ions. The total ACP deposit mass was 1.4 kg/loop. The hazard of the ACP is typically dominated by Mn-56 that arises from Mn and Fe in the base alloy steel, by Co-57, Co-58, that arise from Ni in the base steel and by Co-60 that arises from both Ni and Co in the base steel. The ACP deposit inventory is more than seven times lower than the limit of 10 kg/loop while the ACP inventory in the suspended forms is about 5 times lower than the limit. The ACP assessment for the divertor cooling loop provided values close to the limits, 8.9 kg for the deposit mass and 42 g in the suspended forms. The ACP inventory for VV loops was estimated to be 6
The other important safety requirements are the project release guidelines for the ACPs, tritium and dusts as shown in Table 2.

<table><caption>Table 2 - Project Release Guidelines [10]</caption><thead><tr><th>Events or Conditions</th><th>Project Release Guideline(*)</th></tr></thead><tbody><tr><td><strong>Normal Operation</strong><br>event sequences and plant conditions planned and required for ITER normal operation, including some faults, events or conditions which can occur as a result of the ITER experimental nature</td><td>&lt; 1 g-T as HT and 0.1g-T as HTO and 1 g-metal as AP and <strong>5 g-metal as ACP per year</strong>.</td></tr><tr><td><strong>Incidents</strong><br>deviations from normal operation, event sequences or plant conditions not planned but likely to occur due to failures one or more times during the life of the plant but not including Normal Operation</td><td>&lt; 1 g-T as HT or 0.1 g-T as HTO or 1 g-metal as AP or <strong>1 g-metal as ACP</strong> or equivalent combination of these per event</td></tr><tr><td><strong>Accidents</strong><br>postulated event sequences or conditions not likely to occur during the life of the plant.</td><td>&lt; 50 g-T as HT or 5 g-T as HTO or 50 g-metal as AP or <strong>50 g-metal as ACP</strong> or equivalent combination of these per event.</td></tr></tbody></table>

Note: (*) HT: elemental tritium (including DT); HTO: tritium oxide (includingDTO); AP: divertor or first-wall activation products; ACP: activated corrosion products.

For the occupational radiation exposure (ORE) doses, the following limits and project guidelines have been adopted [10] as shown in Table 3.

<table><caption>Table 3 – ITER limits and project guidelines for ORE doses</caption><thead><tr><th colspan="2">Dose Limits</th></tr></thead><tbody><tr><td>ICRP recommended limit for annual<br>individual worker doses</td><td>20 mSv averaged over 5 years not to exceed<br>50 mSv in any year</td></tr><tr><th colspan="2">Project Guidelines</th></tr><tr><td>Annual individual worker doses</td><td>5 mSv/year</td></tr><tr><td>Individual worker dose for any given shift</td><td>0.5 mSv/shift</td></tr></tbody></table>

## 6 Results of ITER ACP assessment by PACTITER

As written in section 3, many calculations were carried out with the PACTOLE code first and then with the PACTITER code to assess ACP in the PHTS of ITER TCWS, following the several evolutions of the design. In this section the results presented are referred to the latest evolution of the design as and they are fully documented in the related official technical document [8]. The ACP assessment carried out for a single First Wall/Shield cooling loop provided a value of 1.8 g of suspended cruds and 10.9 g of dissolved ions. The total ACP deposit mass was 1.4 kg/loop. The hazard of the ACP is typically dominated by Mn-56 that arises from Mn and Fe in the base alloy steel, by Co-57, Co-58, that arise from Ni in the base steel and by Co-60 that arises from both Ni and Co in the base steel. The ACP deposit inventory is more than seven times lower than the limit of 10 kg/loop while the ACP inventory in the suspended forms is about 5 times lower than the limit. The ACP assessment for the divertor cooling loop provided values close to the limits, 8.9 kg for the deposit mass and 42 g in the suspended forms. The ACP inventory for VV loops was estimated to be 6
kg/loop for mass deposit and 25.6 g/loop in the suspended forms. It was conservatively assumed that the radiological hazard of VV ACP is 100 times lower compared to the FW/shield ACP. The estimated base metal release rates for the different cooling loops of the ITER TCWS are shown in Table 4.

<table><caption>Table 4 – ITER TCWS cooling loop material average release rate</caption><thead><tr><th>Cooling loop type</th><th>Scenario duration [days]</th><th>SS316L release rate [µm/year]</th><th>SS304L (°) release rate [µm/year]</th><th>Cu-alloy release rate [µm/year]</th></tr></thead><tbody><tr><td>FW/shield</td><td>3681</td><td>0.16</td><td>0.07</td><td>(*)</td></tr><tr><td>Divertor</td><td>3681</td><td>0.16</td><td>0.11</td><td>2.18</td></tr><tr><td>VV</td><td>3681</td><td>0.008</td><td>0.047</td><td>(*)</td></tr></tbody></table>

(°) material in the non-irradiated zones (*) no Cu-alloy in this cooling loop

Mass release rates of the VV loop stainless steels are lower due to the lower coolant operating temperature (100 – 103 °C) and to the lower coolant velocity < 0.5 m/s in most of the loop. ACP mass and activity inventory were used in accident analyses involving LOCA with consequent releases to the environment. Among several accident sequences analysed [11], a large DV ex-vessel coolant pipe break provided the largest ACP environmental release, equal to 1.2 % of the project release guidelines (see Table 2).

The ACP radioactive inventory distribution, assessed by the PACTITER code for ITER TCWS, was used to determine the dose rates around its system components (e.g.; piping, main pumps, valves, heat exchangers) during scheduled and unscheduled maintenance. Starting from the radiation field and taking into account the anticipated work effort, the related annual collective ORE was estimated to be 65 pers-mSv [12] for the first wall/shield loops (30) and divertor loop (35). The contribution from VV loops was not estimated being the related ACP radiation hazard negligible as written before.

# 7 PACTITER V3.1: A new version

## 7.1 Modelling

The PACTOLE V2 code has shown some lacks of modelling [13]. Therefore, a new code version, namely PACTOLE V3.0, has been designed to account for recent developments relevant to the behaviour of corrosion products in PWR and to help in understanding and modelling the physical-chemical processes [14].

The PACTOLE V3.0 code is still based on a control volume approach, the primary circuit is represented by an arrangement of several volumes in which transient mass balance equations are solved :

$$ \frac{\partial \dot{m}_i}{\partial t} + (\dot{m}_s - \dot{m}_e) = \sum_{\text{Source}} J_m - \sum_{\text{Sink}} J_m \quad (3) $$

Where $\dot{m}_i$ is the mass of the i$^{th}$ isotope in a considered medium defined as a form for the corrosion products, t is the time, $\dot{m}_s - \dot{m}_e$ is the convective term (balance between input and output) and except for nuclear reactions, which are mass production/loss within the considered medium, $J_m$ is an exchange mass rate between two different media.

Seven different media are taken into account in a control volume and depicted in Figure 3 below.
kg/loop for mass deposit and 25.6 g/loop in the suspended forms. It was conservatively assumed that the radiological hazard of VV ACP is 100 times lower compared to the FW/shield ACP. The estimated base metal release rates for the different cooling loops of the ITER TCWS are shown in Table 4.

<table><caption>Table 4 – ITER TCWS cooling loop material average release rate</caption><thead><tr><th>Cooling loop type</th><th>Scenario duration [days]</th><th>SS316L release rate [µm/year]</th><th>SS304L (°) release rate [µm/year]</th><th>Cu-alloy release rate [µm/year]</th></tr></thead><tbody><tr><td>FW/shield</td><td>3681</td><td>0.16</td><td>0.07</td><td>(*)</td></tr><tr><td>Divertor</td><td>3681</td><td>0.16</td><td>0.11</td><td>2.18</td></tr><tr><td>VV</td><td>3681</td><td>0.008</td><td>0.047</td><td>(*)</td></tr></tbody></table>

(°) material in the non-irradiated zones (*) no Cu-alloy in this cooling loop

Mass release rates of the VV loop stainless steels are lower due to the lower coolant operating temperature (100 – 103 °C) and to the lower coolant velocity < 0.5 m/s in most of the loop. ACP mass and activity inventory were used in accident analyses involving LOCA with consequent releases to the environment. Among several accident sequences analysed [11], a large DV ex-vessel coolant pipe break provided the largest ACP environmental release, equal to 1.2 % of the project release guidelines (see Table 2).

The ACP radioactive inventory distribution, assessed by the PACTITER code for ITER TCWS, was used to determine the dose rates around its system components (e.g.; piping, main pumps, valves, heat exchangers) during scheduled and unscheduled maintenance. Starting from the radiation field and taking into account the anticipated work effort, the related annual collective ORE was estimated to be 65 pers-mSv [12] for the first wall/shield loops (30) and divertor loop (35). The contribution from VV loops was not estimated being the related ACP radiation hazard negligible as written before.

# 7 PACTITER V3.1: A new version

## 7.1 Modelling

The PACTOLE V2 code has shown some lacks of modelling [13]. Therefore, a new code version, namely PACTOLE V3.0, has been designed to account for recent developments relevant to the behaviour of corrosion products in PWR and to help in understanding and modelling the physical-chemical processes [14].

The PACTOLE V3.0 code is still based on a control volume approach, the primary circuit is represented by an arrangement of several volumes in which transient mass balance equations are solved :

$$ \frac{\partial \dot{m}_i}{\partial t} + (\dot{m}_s - \dot{m}_e) = \sum_{\text{Source}} J_m - \sum_{\text{Sink}} J_m \quad (3) $$

Where $\dot{m}_i$ is the mass of the i$^{th}$ isotope in a considered medium defined as a form for the corrosion products, t is the time, $\dot{m}_s - \dot{m}_e$ is the convective term (balance between input and output) and except for nuclear reactions, which are mass production/loss within the considered medium, $J_m$ is an exchange mass rate between two different media. Seven different media are taken into account in a control volume and depicted in Figure 3 below.
<figure><img src="image_4.png" /><figcaption>Figure 3 - Media in a Control Volume for a PACTOLE representation</figcaption></figure>

The transfer mechanisms, which are modelled in the mass balance equations, between all the considered media, are summarised in Figure 4.

<figure><img src="image_5.png" /><figcaption>Figure 4 - Transfer processes between media in a control volume</figcaption></figure>

The corrosion and release processes are formulated in the mass balance equations as functions of their time production rates that now enable to describe the consequences of material surface treatments on the corrosion and release processes and, so that, on the primary circuit contamination [15]. The corrosion kinetics and the release kinetics can be measured for different alloys with different fabrication processes using, for instance, the CORELE loop [16].

## 7.2 Computer Aspects

Combined with a fully object oriented programming language (C++), the PACTOLE V3 code has been written and designed using the Unified Method Language (UML). Thanks to its code architecture, the latest PACTOLE version is an easy evolving computer tool in which new media can be added or removed and in which new models can be tested. Moreover, the class management process, introduced in the PACTOLE code, allows a non-limited number of control volumes, chemical elements, isotopes. The only restriction comes from the memory of the computer on which the code runs and the longer run duration.
<figure><img src="image_4.png" /><figcaption>Figure 3 - Media in a Control Volume for a PACTOLE representation</figcaption></figure>

The transfer mechanisms, which are modelled in the mass balance equations, between all the considered media, are summarised in Figure 4.

<figure><img src="image_5.png" /><figcaption>Figure 4 - Transfer processes between media in a control volume</figcaption></figure>

The corrosion and release processes are formulated in the mass balance equations as functions of their time production rates that now enable to describe the consequences of material surface treatments on the corrosion and release processes and, so that, on the primary circuit contamination [15]. The corrosion kinetics and the release kinetics can be measured for different alloys with different fabrication processes using, for instance, the CORELE loop [16].

## 7.2 Computer Aspects

Combined with a fully object oriented programming language (C++), the PACTOLE V3 code has been written and designed using the Unified Method Language (UML). Thanks to its code architecture, the latest PACTOLE version is an easy evolving computer tool in which new media can be added or removed and in which new models can be tested. Moreover, the class management process, introduced in the PACTOLE code, allows a non-limited number of control volumes, chemical elements, isotopes. The only restriction comes from the memory of the computer on which the code runs and the longer run duration.
The PACTOLE V3 code version is available on UNIX or LINUX workstation and on personal computers using Windows operating system. The first simulations with PACTOLE V3.0 have shown a reasonable agreement with the on-site measurements [17].

## 7.3 Further developments in the PACTOLE/PACTITER code

Major improvements have been achieved in the V3.0 PACTOLE code version for the data processing architecture and numerical analysis for solving transient equations [18]. This new architecture will allow the PACTOLE code of being an integration tool for the complex physics involved in contamination transfer studies. Some physical models have been already modified (among them corrosion and release rates), but there are still both existing models to improve and new models to implement. The making of a wilful work program for improving the physical models and the data is under way.

The chemistry module is being improved for the PACTOLE V3.1 code. A new approach for oxide determination and equilibrium concentration calculation has been developed by CEA. This model, based on a survey of oxides thermodynamic behaviour, is aimed at predicting in a more accurate way the equilibrium concentration values.

Other important steps in the PACTOLE code development for version 3.1 are scheduled within short term:

* Improvement of the corrosion/release mechanism. Based on the present empirical mathematical expression, the impact of macroscopic parameters such as solubility or temperature will be accounted for.

* Addition of a specific module for shutdown. In the present code modelling, only reducing conditions can be treated: a real simulation of oxygenation phase is therefore impossible. Due, for a large part, to the lack of available data, an important effort is devoted to the data collection of oxide characteristics in oxidizing conditions.

It is foreseen that the PACTITER v3.1 code development will profit by these improvements. The major needs related to the adaptation of PACTOLE V3.1 to the fusion case in general and to ITER in particular, with the aim to get PACTITER V3.1 are related to:

* the addition of Cu to the other five elements (Fe, Ni, Co, Cr and Mn);

* the consideration of the variable neutron flux distribution on the diverse FW/shield wet surfaces under neutron bombardment (two orders of magnitude between the maximum and minimum neutron flux value);

* the simulation of pulsed operation characterised by different coolant temperatures and flow rates (five main operating conditions are envisaged for ITER: burn, dwell, cold stand-by, hot stand-by and baking).

# 8 Conclusions

The development and validation work has been scheduled with the aim to have PACTITER V3.1 released within the end of 2006. The application of PACTOLE/PACTITER to the prediction of ACP for fusion reactors has been lasting for more than 10 years. The extensive work of development, qualification and validation through dedicated experiments, and application of PACTITER to ACP assessment, mainly for ITER safety analyses (release in accident conditions and occupational dose to the staff), has produced valuable results. The ultimate aim is to further reduce the uncertainties in the source terms considering the specific material and operating scenarios of ITER machine. This effort will also fulfill some of the requirements for ITER licensing in Europe.

## Acknowledgements

This work, supported by the European Communities under the Contract of Association between EURATOM on one side and CEA / ENEA on the other side, was carried out within the framework of the European Fusion
The PACTOLE V3 code version is available on UNIX or LINUX workstation and on personal computers using Windows operating system. The first simulations with PACTOLE V3.0 have shown a reasonable agreement with the on-site measurements [17].

## 7.3 Further developments in the PACTOLE/PACTITER code

Major improvements have been achieved in the V3.0 PACTOLE code version for the data processing architecture and numerical analysis for solving transient equations [18]. This new architecture will allow the PACTOLE code of being an integration tool for the complex physics involved in contamination transfer studies. Some physical models have been already modified (among them corrosion and release rates), but there are still both existing models to improve and new models to implement. The making of a wilful work program for improving the physical models and the data is under way.

The chemistry module is being improved for the PACTOLE V3.1 code. A new approach for oxide determination and equilibrium concentration calculation has been developed by CEA. This model, based on a survey of oxides thermodynamic behaviour, is aimed at predicting in a more accurate way the equilibrium concentration values.

Other important steps in the PACTOLE code development for version 3.1 are scheduled within short term:

* Improvement of the corrosion/release mechanism. Based on the present empirical mathematical expression, the impact of macroscopic parameters such as solubility or temperature will be accounted for.

* Addition of a specific module for shutdown. In the present code modelling, only reducing conditions can be treated: a real simulation of oxygenation phase is therefore impossible. Due, for a large part, to the lack of available data, an important effort is devoted to the data collection of oxide characteristics in oxidizing conditions.

It is foreseen that the PACTITER v3.1 code development will profit by these improvements. The major needs related to the adaptation of PACTOLE V3.1 to the fusion case in general and to ITER in particular, with the aim to get PACTITER V3.1 are related to:

* the addition of Cu to the other five elements (Fe, Ni, Co, Cr and Mn);

* the consideration of the variable neutron flux distribution on the diverse FW/shield wet surfaces under neutron bombardment (two orders of magnitude between the maximum and minimum neutron flux value);

* the simulation of pulsed operation characterised by different coolant temperatures and flow rates (five main operating conditions are envisaged for ITER: burn, dwell, cold stand-by, hot stand-by and baking).

# 8 Conclusions

The development and validation work has been scheduled with the aim to have PACTITER V3.1 released within the end of 2006. The application of PACTOLE/PACTITER to the prediction of ACP for fusion reactors has been lasting for more than 10 years. The extensive work of development, qualification and validation through dedicated experiments, and application of PACTITER to ACP assessment, mainly for ITER safety analyses (release in accident conditions and occupational dose to the staff), has produced valuable results. The ultimate aim is to further reduce the uncertainties in the source terms considering the specific material and operating scenarios of ITER machine. This effort will also fulfill some of the requirements for ITER licensing in Europe.

## Acknowledgements

This work, supported by the European Communities under the Contract of Association between EURATOM on one side and CEA / ENEA on the other side, was carried out within the framework of the European Fusion
Development Agreement. The views and opinions expressed herein do not necessarily reflect those of the European Commission. The authors would thank V. Blet and P. Schindler for useful discussions during the preparation of the present paper.

## References

1. P. Beslu, "PACTOLE: a calculation code for predicting corrosion products behavior and activation in PWR primary coolant systems", Tech. Note SCOS/LCC 90-096 (1990)

2. L. Di Pace, G. Cambi, D. G. Cepraga, E. Sobrero, M. Costa, "Activated corrosion products in ITER first wall and shielding blanket heat transfer system", Proceedings of 16th Symposium on Fusion Engineering, Urbana, Illinois, USA (1995)

3. S. Nisan, L. Di Pace, J-C. Robin, "Evaluation of the Activated Corrosion Product Source Term for ITER Heat Transfer System", *Fusion Technology 1996, Proceedings of 19th Symposium on Fusion Technology*, Elsevier, (1996) p.1871-1874

4. S. Eriksson, L. Permer, Aqueous Corrosion of Copper Alloys - Literature Survey, ITER task CTA-EU-T10, Studsvik, (1995)

5. D. You, S. Lefévre, P. Gerlinger, A. Chéniere, "Thermodynamic stability and solubility of copper and copper oxides", CEA Tech. Report SCECF 420, (1997)

6. L. Di Pace, D. Tarabelli, D. You, "Development of the PACTITER code and its application to the assessment of the ITER Divertor cooling loop corrosion products", *Fusion Technology 34*, No. 3 part 2, (1998) p. 733-737

7. L. Di Pace, D.G. Cepraga, "Final report on Activated Corrosion Products Evaluation for the ITER-FDR PHTS", ERG-FUS TN SIC 12/99, (1999)

8. ITER Generic Site Safety Report, Volume III, IDoMS G 84 RI 3 01-07-13 R1.0, (2001)

9. ITER Safety Analysis Data List, Vers. 4.0.1, IDoMS G 81 RI 10 03-08-08 W 0.1 (2003)

10. ITER Generic Site Safety Report, Volume I, IDoMS G 84 RI 1 01-07-09 R 1.0, (2001)

11. ITER Generic Site Safety Report, Volume VII, IDoMS G 84 RI 6 01-07-10 R 1.0, (2001)

12. ITER Generic Site Safety Report, Volume VI, IDoMS G 84 RI 6 01-07-10 R 1.0, (2001)

13. D. Tarabelli, S. Anthoni, D. Féron, P. Ridoux, L. Guinard, C. Brun, A. Long, "Status and Future Plans of the PACTOLE Code Predicting the Activation and Transport of Corrosion Products in PWR", Proceedings of the Japan Atomic Industrial Forum International Conference on Water Chemistry in Nuclear Power Plants, Kashiwasaki, October 13-16, *Water Chemistry'98*, JAIF, Tokyo (1998) p. 301-305

14. C. Marchetto, D. Tarabelli, D. You, C. Andrieu, A. Long, D. Zeitoun, "PACTOLE V3 : a new code version to predict corrosion product contamination", Proceedings of the International conference of water chemistry of nuclear reactor systems, Bournemouth, UK, 22-26 October 2000, BNES, London (2000) p. 224-229

15. F. Coulet, "Etude et modélisation de l'influence des matériaux sur la contamination du circuit primaire des réacteurs à eau pressurisée par les produits de corrosion", PhD thesis, INPG, (Grenoble), (1996)

16. Schindler P., V. Blet, L. Di Pace, "Stainless steel release rate evaluation in ITER operating conditions", this conference

17. F. Nguyen, H. Marteau, F. Dacquait, N. Perot, G. Ranchoux, L. Guinard, A. Long, "First numerical simulations of contamination of the PWR primary circuit by activated corrosion products with the PACTOLE V3.0 code", Proceedings of the International conference on Water chemistry in nuclear reactors systems, October 11th – 14th, San Francisco USA, (2004)

18. C. Marchetto, "Modélisation et Simulation Numérique du Transport des Produits de Corrosion dans le Circuit Primaire des Réacteurs à Eau Pressurisée", PhD thesis, Université de Provence (Aix-Marseille I) (2002)
Development Agreement. The views and opinions expressed herein do not necessarily reflect those of the European Commission. The authors would thank V. Blet and P. Schindler for useful discussions during the preparation of the present paper.

## References

1. P. Beslu, "PACTOLE: a calculation code for predicting corrosion products behavior and activation in PWR primary coolant systems", Tech. Note SCOS/LCC 90-096 (1990)

2. L. Di Pace, G. Cambi, D. G. Cepraga, E. Sobrero, M. Costa, "Activated corrosion products in ITER first wall and shielding blanket heat transfer system", Proceedings of 16th Symposium on Fusion Engineering, Urbana, Illinois, USA (1995)

3. S. Nisan, L. Di Pace, J-C. Robin, "Evaluation of the Activated Corrosion Product Source Term for ITER Heat Transfer System", *Fusion Technology 1996, Proceedings of 19th Symposium on Fusion Technology*, Elsevier, (1996) p.1871-1874

4. S. Eriksson, L. Permer, Aqueous Corrosion of Copper Alloys - Literature Survey, ITER task CTA-EU-T10, Studsvik, (1995)

5. D. You, S. Lefévre, P. Gerlinger, A. Chéniere, "Thermodynamic stability and solubility of copper and copper oxides", CEA Tech. Report SCECF 420, (1997)

6. L. Di Pace, D. Tarabelli, D. You, "Development of the PACTITER code and its application to the assessment of the ITER Divertor cooling loop corrosion products", *Fusion Technology 34*, No. 3 part 2, (1998) p. 733-737

7. L. Di Pace, D.G. Cepraga, "Final report on Activated Corrosion Products Evaluation for the ITER-FDR PHTS", ERG-FUS TN SIC 12/99, (1999)

8. ITER Generic Site Safety Report, Volume III, IDoMS G 84 RI 3 01-07-13 R1.0, (2001)

9. ITER Safety Analysis Data List, Vers. 4.0.1, IDoMS G 81 RI 10 03-08-08 W 0.1 (2003)

10. ITER Generic Site Safety Report, Volume I, IDoMS G 84 RI 1 01-07-09 R 1.0, (2001)

11. ITER Generic Site Safety Report, Volume VII, IDoMS G 84 RI 6 01-07-10 R 1.0, (2001)

12. ITER Generic Site Safety Report, Volume VI, IDoMS G 84 RI 6 01-07-10 R 1.0, (2001)

13. D. Tarabelli, S. Anthoni, D. Féron, P. Ridoux, L. Guinard, C. Brun, A. Long, "Status and Future Plans of the PACTOLE Code Predicting the Activation and Transport of Corrosion Products in PWR", Proceedings of the Japan Atomic Industrial Forum International Conference on Water Chemistry in Nuclear Power Plants, Kashiwasaki, October 13-16, *Water Chemistry'98*, JAIF, Tokyo (1998) p. 301-305

14. C. Marchetto, D. Tarabelli, D. You, C. Andrieu, A. Long, D. Zeitoun, "PACTOLE V3 : a new code version to predict corrosion product contamination", Proceedings of the International conference of water chemistry of nuclear reactor systems, Bournemouth, UK, 22-26 October 2000, BNES, London (2000) p. 224-229

15. F. Coulet, "Etude et modélisation de l'influence des matériaux sur la contamination du circuit primaire des réacteurs à eau pressurisée par les produits de corrosion", PhD thesis, INPG, (Grenoble), (1996)

16. Schindler P., V. Blet, L. Di Pace, "Stainless steel release rate evaluation in ITER operating conditions", this conference

17. F. Nguyen, H. Marteau, F. Dacquait, N. Perot, G. Ranchoux, L. Guinard, A. Long, "First numerical simulations of contamination of the PWR primary circuit by activated corrosion products with the PACTOLE V3.0 code", Proceedings of the International conference on Water chemistry in nuclear reactors systems, October 11th – 14th, San Francisco USA, (2004)

18. C. Marchetto, "Modélisation et Simulation Numérique du Transport des Produits de Corrosion dans le Circuit Primaire des Réacteurs à Eau Pressurisée", PhD thesis, Université de Provence (Aix-Marseille I) (2002)