ML20195K127
| ML20195K127 | |
| Person / Time | |
|---|---|
| Site: | Paducah Gaseous Diffusion Plant |
| Issue date: | 11/20/1998 |
| From: | Pierson R NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Toelle S UNITED STATES ENRICHMENT CORP. (USEC) |
| References | |
| NUDOCS 9811250188 | |
| Download: ML20195K127 (2) | |
Text
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r November 20, 1998 Mr. Stevsn A. To lls, Manager Nuclear Regulatory Assurance and Policy U. S. Enrichment Corporation 2 Democracy Center 6903 Rockledge Drive Bethesda, MD 20817 i
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Dear Mr. Toelle:
5 This letter documents a discussion between Ms. Merri Horn and Mr. Andrew Persinko of my j
staff and Mr. Steve Routh and Mr. Ma:k Smith of your staff that was held on November 19, 1998. Your staff expressed concern that the seismic modifications underway at the Paducah Gaseous Diffusion Plant were introducing new uncertainties in the ability of the plant structures to withstand a 170 mile per hour (mph) wind and that this presented a potential unreviewed safety question. Your staff also indicated that the seismic modification project had been put on hold until this issue was resolved.
We do not believe that an unreviewed safety question has been introduced. The safety analysis report (SAR) does not state that the plant was designed to withstand a 170 mph wind.
Rather, the 170 mph wind, as included in the SAR, is an estimate of when structural steel failure begins to occur and is included for perspective. The stated return period of a 170 mph wind is 58,000 years. The evaluation basis wind is considered to be 70 mph with a return period of about 237 years. Information in the SAR upgrade further supports the use of 70 mph as the evaluation basis wind.
Based on the discussion, it is our understanding that the facility does meet, and will continue to meet throughout the modification work, the evaluation basis wind of 70 mph. Based on the discussion, your staff indicated they would inform the plant to continue work on the seismic modification project.
If you have any questions, please contact Ms. Merri Horn of my staff at (301) 415-8126.
Sincere!
Wne3 MgnedBY Robert C. Pierson, Chief Special Projects Branch Division of Fuel Cycle Safety and Safeguards, NMSS Docket Nos. 70-7001 Certificat' GDP-1 e
cc: Howard Pulley, PGDP Randall DeVault, DOE
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\\. * *. [t WASHINGTON. D.C. 20555-00C1 November 20, 1998 Mr. Steven A. Toelle, Manager Nuclear Regulatory Assurance and Policy U. S. Enrichment Corporation 2 Democracy Center 6903 Rockledge Drive Bethesda, MD 20817
Dear Mr. Toelle:
t This letter documents a discussion between Ms. Merri Horn and Mr. Andrew Persinko of my staff and Mr. Steve Routh and Mr. Mark Smith of your staff that was held on November 19, 1998. Your staff expressed concern that the seismic modifications underway at the Paducah l
Gaseous Diffusion Plant were introducing new uncertainties in the ability of the plant structures l
to withstand a 170 mile per hour (mph) wind and that this presented a potential unreviewed safety question. Your staff also indicated that the seismic modification project had been put on hold until this issue was resolved.
4 We do not believe that an unreviewed safety question has been introduced. The safety analysis report (SAR) does not state that the plant was designed to withstand a 170 mph wind.
Rather, the 170 mph wind, as included in the SAR, is an estimate of when structural steel failure begins to occur and is included for perspective. The stated return period of a 170 mph wind is 58,000 years. The evaluation basis wind is considered to be 70 mph with a return period of about 237 years. Information in the SAR upgrade further supports the use of 70 mph L
as the evaluation basis wind.
Based on the discussion, it is our understanding that the facility does meet, and will continue to i
meet throughout the modification work, the evaluation basis wind of 70 mph. Based on the discussion, your staff indicated they would inform the plant to continue work on the seismic modification project.
i If you have any questions, please contact Ms. Merri Horn of my staff at (301) 415-8126.
L Sincerely, ft. (&
Robert C. Pierson, Chief Special Projects Branch Division of Fuel Cycle Safety and Safeguards, NMSS Docket Nos. 70-7001 Certificate GDP-1 i
cc: Howard Puley, PGDP Randall DeVault, DOE l
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