ML20206B481
| ML20206B481 | |
| Person / Time | |
|---|---|
| Issue date: | 08/19/1988 |
| From: | Sheron B NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| To: | Stolmar A AFFILIATION NOT ASSIGNED |
| Shared Package | |
| ML20206B404 | List: |
| References | |
| NUDOCS 8811150460 | |
| Download: ML20206B481 (1) | |
Text
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9
. uq[g UNITED STATES 4
NUCLEAR REGULATORY COMMISSION y
p, WAsm NoToN. O. C. 20555 ol AUG 19 1988 Mr. Aladar Stolmar 1819 Atkinson Place Pittsburgh, PA 15235
Dear Mr. Stoimar:
We thank you for your letter of August 1,1988 and the enclosed copy of NS-RAT-SAA-88-006. Several of our staff, who have been involved with analytical and experimental studies of high temperature oxidation of zirconium, have read both your letter and the enclosure. You should be aware that our present understanding of zirconium oxidation rests in part on some of the studies performed for the NRC and for its predecessor agency, the AEC, in which Knudsen Effusion cells coupled with time-of-flight mass spectrometers were used to vaporize zirconium and uranium and the binary and ternary oxides, to verify the evolving species, and to confirm the effective vapor pressures as a function of effusion cell temp 3ratures. Earlier studies had shown that compound materials such as oxides may evaporate congruently as the compounds, or may "break down" and evaporate as the elements or as other compounds. The time-of-flight mass spectrometer was particularly useful in identifying each of these evolving species.
In other NRC-funded tests, samples of zirconium were laser heated in vacuum and in inert and reducing atmospheres to a wide range of temperatures, including melting temperatures and above, and then oxygen and/or steam jets were impacted on the high temperature samples to establish the reaction rates at each temperature.
As you can see, we, too, have been concerned that we model oxidation reactions correctly. Our modeling work is continuing and we have forwarded copies of your letter and enclosure to scientists at the three laboratories which have the current lead in helping us develop models of severe accident fuel damage progression for their consideration.
1 Sincerely, j
dA VA N Brian W. Shercn, Director Division of Systems Research Office of Nuclear Regulatory Research cc:
L. Hochreiter, W
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W. Johnson, W 89111504AO 801108 PDR TOPkP ENVWEST C
PNU l
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