Radiation embrittlement vessel

Popp, K., Brauer, G., and Leonhardt, W.-D. et al., (1989) in Radiation Embrittlement of Nuclear Reactor Pressure Vessel Steels An International Review, ASTMSTP1011, ed. By L.E. Steele (American Society fro Testing and Materials, Philadelphia)... 

Low pressure in the primary circuit enables to reduce the thickness of reactor vessel walls and to use for its fabricating less strong austenite steel being resistant to radiation embrittlement under operation conditions and eliminate the possibility of vessel brittle damage. This enhances safety and eliminates the restrictions on temperature change rate on conditions of thermocycling strength and radiation life time of reactor vessel. 

AR378 1.99 Radiation embrittlement of reactor vessel materials (Draft ME 305-4, Proposed revision 2,... 

Adequate operational procedures may also contribute to reducing the probability of generating a PIE. Examples include the prevention of excessive thermal stresses in metal pressure vessels and the monitoring of vessel material for radiation embrittlement the limitation of plant transients by the use of pressure relief valves and safety features activated by the protection system prohibitions or restrictions during the conduct of dangerous operations the use of seismic instruments to provide data for the assessment of the condition of the plant for continued operation following an earthquake and the control of... 

Key words pressurized water reactor (PWR), reactor pressure vessel (RPV), surveillance database, radiation embrittlement. 

NRC 19 ), Regulatory Guide 1.99 Revision 2, Radiation Embrittlement of Reactor Vessel Materials, May, Office of Nuclear Regulatory Research, U.S. Nuclear Regulatory Commission, Washington, DC. 

Randall P (1986), Basis for Revision 2 of the US Nuclear Regulatory Commission s Regulatory Guide 1.99, Radiation Embrittlement in Nuclear Pressure Vessel Steels An International Review (2nd Volume),STP 909, Steele LE (ed.), American Society for Testing and Materials, Philadelphia, PA, pp. 149-162. 

Abstract This chapter describes the embrittlement processes in WWER reactor pressure vessel (RPV) materials during operation - radiation embrittlement and thermal ageing. Current trend curves for both types of WWER RPV materials are given and explained. Surveillance specimen programmes are shown, as their results are used for RPV integrity and lifetime evaluation. Finally, anneahng of the RPV is proposed as the most efficient mitigation measure. 

Key words WWER reactor pressure vessel, radiation embrittlement,... 

The beltUne regions of the WWER-440A -213 (i.e. second generation) pressure vessels were also manufactured from 15Kh2MFAA steel, but most of the V-213 pressure vessels have low phosphorus and copper contents and are similar in impurity content to the WWER-1000 pressure vessels with strict requirements on the residual element (copper, phosphorus, arsenic, tin and antimony) content, i.e. their steel and welds are of 15Kh2NMFAA quality. Thus, radiation embrittlement does not seem to be a limiting factor... 

The approach for German vessels is again essentially the same as the US method using initial RT m and ARTndt = AT4U for radiation embrittlement. German standards are used as defined in the recently revised KTA 3203 (KTA, 2001). The ISO tup is used for Charpy tests, like the French method. The use of RTt as defined in the ASME Code Cases is allowed in KTA 3203. 

R B Jones and C J Bolton, Neutron radiation embrittlement studies in support of continued operation and validation by sampling of Magnox reactor steel pressure vessels and components, Proc. 24 Water Reactor Safety Information Meeting, NUREG/CP-0157, US Nuclear Regulatory Commission, Washington, DC, 1997, 2,25-48. 

It is widely known that radiation embrittlement behaviour of reactor pressure vessel (RPV) steels depends on various parameters such as material composition, neutron flux and irradiation temperature. Sound understanding and modelling of embrittlement mechanisms require systematic knowledge of effects of individual parameters and their synthesis on microstructural development and then mechanical properties. Most such knowledge has been obtained from single-parameter experiments using test reactor irradiation. This is because test reactor irradiation allows researchers to obtain mechanical property data together with microstructural data on materials with well-controlled chemical compositions under well-controlled irradiation conditions such as flux and temperature. Surveillance data in commercial power reactors are non-systematic in this context and relevant microstructural data are very scarce. 

H.S. Palme, Radiation Embrittlement Sensitivity of Reactor Pressure Vessel Steels, BAW-10056 Topical Report, Babcock and Wilcox, Lynchburg, VA, March 1973. 

N. Soneda, C. English and W. Server, Use of an offset in assessing radiation embrittlement data and predictive models , Proc. ASME 2006 Pressure Vessels and Piping Division Conference, American Society of Mechanical Engineers, New York, PVP2006-ICPVT-11-93369. 

PN. Randall, Basis for Revision 2 of the US. Nuclear Regulatory Commission s Regulatory Guide 1.99, Radiation Embrittlement of Nuclear Pressure Vessel... 

C. Gnionnet,Y. Robin, C. Flavier, A. Lefort, D. Gros and R. Perdrean, Radiation embrittlement of a PWR vessel steel effects of impnrities and nickel content . Effects of Radiation on Materials Tenth International Symposium, ASTM STP725, D. Kramer, H.R. Brager and J.S. Perrin (eds), American Society for Testing and Materials, Philadelphia, PA, 1981, pp. 20-37. 

KTA, Monitoring the Radiation Embrittlement of Materials of the Reactors Pressure Vessel of Light Water Reactors, KTA 3203 (3/84), Nnclear Standards... 

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