Abstract
The processes of metal embrittlement induced by neutron irradiation embrittlement (NIE) and neutron re-irradiation embrittlement (NRE) of the rector pressure vessel (RPV) are investigated. Radiation lifetime is calculated using two approaches for re-embrittlement: a conservative law and a lateral shift of the critical transition temperature curve after neutron irradiation. In order to prevent NIE the following measures have been taken at the Kozloduy NPP: loading of dummy elements into core periphery; heating the water for emergency core cooling to 55{sup o} C; fast acting valves in the main steam piping, etc. The critical embrittlement temperature, the residual part of temperature shift and the radiation lifetime have been calculated for units 1 - 4 using the two approaches and updated information on P and Cu impurities content. It is concluded that if the lateral re-embrittlement law is adopted and the P content does not exceed 0.05%, all RPV should reach their design lifetime. The NIE in WWER-440/230 is related to C and P content in the weld 4 and is negligible for the Unit 4 in particular, which has low impurities content. In order to reach the design lifetime of the Units 1 - 3 it is necessary to install MSIV.
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Vodenicharov, S;
[1]
Kamenova, Tz;
[1]
Tzokov, P;
Videnov, A;
[2]
Pekov, B
[3]
- Bylgarska Akademiya na Naukite, Sofia (Bulgaria). Inst. po Metaloznanie i Tekhnologiya na Metalite
- Kombinat Atomna Energetika, Kozloduj (Bulgaria)
- Committee on the Use of Atomic Energy for Peaceful Purposes, Sofia (Bulgaria)
Citation Formats
Vodenicharov, S, Kamenova, Tz, Tzokov, P, Videnov, A, and Pekov, B.
Kozloduy NPP WWER-440/230 reactor pressure vessel radiation lifetime.
Bulgaria: N. p.,
1995.
Web.
Vodenicharov, S, Kamenova, Tz, Tzokov, P, Videnov, A, & Pekov, B.
Kozloduy NPP WWER-440/230 reactor pressure vessel radiation lifetime.
Bulgaria.
Vodenicharov, S, Kamenova, Tz, Tzokov, P, Videnov, A, and Pekov, B.
1995.
"Kozloduy NPP WWER-440/230 reactor pressure vessel radiation lifetime."
Bulgaria.
@misc{etde_462935,
title = {Kozloduy NPP WWER-440/230 reactor pressure vessel radiation lifetime}
author = {Vodenicharov, S, Kamenova, Tz, Tzokov, P, Videnov, A, and Pekov, B}
abstractNote = {The processes of metal embrittlement induced by neutron irradiation embrittlement (NIE) and neutron re-irradiation embrittlement (NRE) of the rector pressure vessel (RPV) are investigated. Radiation lifetime is calculated using two approaches for re-embrittlement: a conservative law and a lateral shift of the critical transition temperature curve after neutron irradiation. In order to prevent NIE the following measures have been taken at the Kozloduy NPP: loading of dummy elements into core periphery; heating the water for emergency core cooling to 55{sup o} C; fast acting valves in the main steam piping, etc. The critical embrittlement temperature, the residual part of temperature shift and the radiation lifetime have been calculated for units 1 - 4 using the two approaches and updated information on P and Cu impurities content. It is concluded that if the lateral re-embrittlement law is adopted and the P content does not exceed 0.05%, all RPV should reach their design lifetime. The NIE in WWER-440/230 is related to C and P content in the weld 4 and is negligible for the Unit 4 in particular, which has low impurities content. In order to reach the design lifetime of the Units 1 - 3 it is necessary to install MSIV. A verification of chemical composition of the Unit 1 RPV weld 4 metal is recommended. 7 refs., 3 figs., 6 tabs.}
place = {Bulgaria}
year = {1995}
month = {Dec}
}
title = {Kozloduy NPP WWER-440/230 reactor pressure vessel radiation lifetime}
author = {Vodenicharov, S, Kamenova, Tz, Tzokov, P, Videnov, A, and Pekov, B}
abstractNote = {The processes of metal embrittlement induced by neutron irradiation embrittlement (NIE) and neutron re-irradiation embrittlement (NRE) of the rector pressure vessel (RPV) are investigated. Radiation lifetime is calculated using two approaches for re-embrittlement: a conservative law and a lateral shift of the critical transition temperature curve after neutron irradiation. In order to prevent NIE the following measures have been taken at the Kozloduy NPP: loading of dummy elements into core periphery; heating the water for emergency core cooling to 55{sup o} C; fast acting valves in the main steam piping, etc. The critical embrittlement temperature, the residual part of temperature shift and the radiation lifetime have been calculated for units 1 - 4 using the two approaches and updated information on P and Cu impurities content. It is concluded that if the lateral re-embrittlement law is adopted and the P content does not exceed 0.05%, all RPV should reach their design lifetime. The NIE in WWER-440/230 is related to C and P content in the weld 4 and is negligible for the Unit 4 in particular, which has low impurities content. In order to reach the design lifetime of the Units 1 - 3 it is necessary to install MSIV. A verification of chemical composition of the Unit 1 RPV weld 4 metal is recommended. 7 refs., 3 figs., 6 tabs.}
place = {Bulgaria}
year = {1995}
month = {Dec}
}