Studies of Corrosion of Materials by Lead Alloys for Advanced Reactor and Nuclear Waste Amelioration Applications
EMSL Project ID
6498
Abstract
Lead alloys have application as non-moderating coolants for advanced reactors and as coolants/targets in spallation neutron sources. The resulting high energy neutron environment fissions minor actinides in nuclear reactor waste. The advantages of reduction of the actinide loading in these systems include a significant reduction in the radiotoxicity over time of the wastes, the utilization of energy normally wasted, and a drop in the proliferation risk.Lead Bismuth Eutectic (LBE) is used as coolant by the Russians in the Alpha class nuclear submarine and the BREST power plant. However, lead alloy coolants aggressively attack structural steels. Russian practice is to introduce oxygen into the LBE, forming protective oxide layers on the structural steels.
We, in collaboration with LANL, have characterized structural steels both before and after exposure to high temperature LBE at the CU-1M test loop at IPPE in Russia (DOE Advanced Fuel Cycle Program Grant No. DE-FG04-2001AL67358). We have presented our results at 4 conferences, one refereed conference proceeding accepted (attached), and one journal article (in preparation). We find that more resistant steels form a different protective oxide (primarily chromium oxide) than the less resistant steels (which formed a mixed iron/chromium oxide/spinel).
We wish to utilize EMSL facilities (small spot XPS and scanning Auger instrument) to continue these investigations along two fronts:
First we wish to pursue the suggestion that for 300 class stainless steels grain size and surface preparation effects1 create a laterally differentiated chromium distribution at the surface leading to a primarily chromium oxide layer for small grain (approximately 10 micron) steels and a mixed oxide for large grain (approximately 40 micron) steels. We request 2 days on the scanning Auger instrument where we will look at the surface of D9, annealed 316L, and cold rolled 316L to see if similar trends are observed on these 300 class steels. Further, as time allows, we shall look at martensitic (HT9) and specialty steels (EP328). We shall be able to suggest improved surface preparation of nuclear rated 316L steels (both before and after assembly) that will significantly improve the performance of advanced lead alloy cooled reactors and spallation neutron sources.
Second, in collaboration with Dr. Eric Loewen of INEEL, we wish to characterize the chemical species in the surface oxide of Fe/(Cr)Si alloys exposed to LBE at INEEL (LDRD funded). These alloys were suggested by the good corrosion resistance of EP328 (a Russian silicon/chromium steel). We request 2 days of time on the Quantum 2000 to look at the transverse sections of the oxidized (oxide layer thickness ~10-20 micron) samples. These results will be presented both as a talk at the spring ANS meeting and as a paper published in a refereed journal.
Due to the small size of the features of interest, the unique capabilities of the EMSL Quantum 2000 and scanning Auger instruments are required.
1. D. R BAER, "Protective and non-protective oxide formation on 304 stainless steel," ppl. Surf. Sci. 7, 69-82 (1981); D. R. BAER and M.D. MERZ, "Differences in oxides on large-and small-grained 304 stainless steel," Metall. Trans. A 11A (1980).
Project Details
Project type
Exploratory Research
Start Date
2004-01-02
End Date
2006-01-23
Status
Closed
Released Data Link
Team
Principal Investigator
Related Publications
Spectroscopic and microscopic study of the corrosion of iron–silicon steel by lead–bismuth eutectic (LBE) at elevated temperatures