ML19269C460
| ML19269C460 | |
| Person / Time | |
|---|---|
| Site: | 07001100 |
| Issue date: | 12/21/1978 |
| From: | Lichtenberger ABB COMBUSTION ENGINEERING NUCLEAR FUEL (FORMERLY |
| To: | Galen Smith NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| Shared Package | |
| ML19269C459 | List: |
| References | |
| NUDOCS 7902030004 | |
| Download: ML19269C460 (2) | |
Text
.;
.C-E Power Systems Tel. 203/638-1911 Combustion Engineenng. inc.
Telex: 9 9297 9
1000 Prospect Hill Road Windsor, Connecticut 06095 M SYSTEMS POWER December 21, 1978 SNM License 1067 Docket 70-1100 U. S. Nuclear Regulatory Commission Region I 631 Park Avenue King of Prussia, PA 19406 Attention:
Mr. George H. Smith, Chief Fuel Facility & Material Safety Branch
Reference:
Letter from G. H. Smith to H. V. Lichtenberger, dated 12/5/78 Inspection 70-1100/78-10 Gentlemen:
This is in response to the above referenced letter in which you reported an infraction that was determined during your inspector's visit to our facility on November 1-3, 1978.
Appendix A Paragraph 14.7 of the license application, incorporated as Condition 9 of License No. SNM-1067, requires, in part, that the adequacy of (ventilation) sampling techniques to obtain representative samples be verified.
Nine out of ten ventilation systems licensed under SNM-1067 are filtered by absolute filters which are 99.97% efficient at 0.3 micron particle size.
For greater than 0.3 micron particles, the filter efficiency approaches 100%.
Therefore, tlie discharge airstream from these vent systems (where the sample probes are located) is composed of a mixture of airborne UO2 particles of less than 1 micron (geometric diameter).
At a maximum density of 10.96 gm/cc for UO, the calculated maximum aerodynamic equivalent diameter is less than 3.5 2
microns.
Section 4.2.2.3 of ANSI N13.1-1969 states in part that "... distortion in particle size distributions (leading to nonrepresentative sampling) may occur when the velocity of the sampled air entering the sample probe is significantly different from the velocity of the air in the stream sampled... However, particles smaller than an aerodynamic diameter of about 5 microns are able to follow the streamlines of the air, and the fractionation error is not great".
This fact, when applied to the 9 filtered systems indicates that anisokinetic (nonrepresentative) sampling is not possible due to the inherent design of the system. The one ventilation system which is unfiltered presents the only risk of nonrepresentative sampling.
Flow measurement profiles across the discharge duct as well as flow measurements of the sampling air velocity will be made within 90 days of the date of this letter to confirm the fact that sampling is isckinetic for this system.
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