ML081090558

Pilgrim April 2008 Evidentiary Hearing - Staff Exhibit 25, Corrosion Induced by Low-Energy Radionuclides (2004) Excerpt - Strategy for Controlling Corrosion

ML081090558
Person / Time
Site:	Pilgrim
Issue date:	12/31/2004
From:	Bellanger G Elsevier
To:	NRC/SECY
SECY RAS
References
50-293-LR, ASLBP 06-848-02-LR, Pilgrim-Staff-63, RAS J-93
Download: ML081090558 (2)

Text

/34S CORROSION INDUCED BY LOW-ENERGY RADIONUCLIDES I-Modeling of Tritium and Its Radiolytic and Decay Products Formed in Nuclear Installations DOCKETED U.S. NUCLEAR REGULATMR GOMtAS"e IntoieM~oft4yv Aoril 15. 2008 (10:00am) Dacwe N~.taiL-LOfca Exbtw No. tP OFFICE OF SECRETARY O~Dby: rMICentilloens Inevn___

RI 11FMAI<ON(,q ANFl Arl.ll IfI'fIATIfN. 5.qTAF:=

Acdon Talef: Q ýi) EJECTED WIT14DRA Gilbert Bellanger Selongey, France J9R~Y ~

2004 Amsterdam 9 Boston

• Heidelberg

• London o New York

• Oxford Paris 9 San Diego e San Francisco

• Singapore e Sidney a Tokyo

Chapter4 STRATEGY FOR CONTROLLING CORROSION 4I First of all, the following question can be asked: why carry out corrosion tests?

Before answering this question, we must recognize that there are very few laboratories in the world that use highly concentrated tritium and tritiated water. Our laboratory is the only one in France. It is not a question of tritiated water traces present in light water, but the reverse. We do not work with light water as is the case in PWR or other nuclear reactors. No steel or super stainless alloy has been previously tested in this highly concentrated tritiated aqueous medium by anyone in France. By its nature, this medium is very reactive and its properties are completely different from the light water in nuclear power stations, which although it can be activated, contains much lower concentrations of radiolytic hydrogen peroxide, among other species, than in our closed storage units. In addition, we are not confronted with microbial corrosion as in the secondary circuits of PWR power stations.

No living species could withstand the tritiated water concentrations we have. The behaviors and the types of corrosion of stainless steels or superalloys are thus completely different in our installations and no comparison is possible. After this digression, in answering the question, our corrosion tests, which are specific to tritium, must make it possible:

- to study the initiation and evolution of corrosion phenomena in the presence of tritium.,

concentrated tritiated water and radiolytic species,

- to select materials best adapted to the envisaged use in concentrated tritiated media, to know and understand their behavior in the various tritiated media,

• to monitor their corrosion resistance in a well-specified tritiated medium.

Finally, to reach the overall goal, the operator of a tritium gas and tritiated water nuclear pwprocessing installation, must, to ensure its correct operation and safety, apply a material and q1uipment maintenance and monitoring policy as well as an on-going survey of new ma-jc'4als for replacing corroded components. If he does not apply this policy and is satisfied

,ý,th a simple monitored storage system, his installation will soon become obsolete with Tespect to those of other potential competitors in the tritium market for nuclear fusion. To yo"0id this, he must implement resources for monitoring and follow-up of the most highly i 8ssed and defective components as well as for specialized examinations that can be di-yc.y applied to his installations. Various inspection methods have been extensively used i* meet these requirements. These make possible: (1) analysis of tritiated water and tritium nc radiolytic species and impurities. This knowledge makes it possible to determine 35

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