ML20135A099
| ML20135A099 | |
| Person / Time | |
|---|---|
| Site: | Portsmouth Gaseous Diffusion Plant |
| Issue date: | 02/24/1997 |
| From: | Woolley R UNITED STATES ENRICHMENT CORP. (USEC) |
| To: | Devault R ENERGY, DEPT. OF |
| References | |
| NUDOCS 9702260447 | |
| Download: ML20135A099 (4) | |
Text
United States Enrichment Corocrat:cn j
s 2 Democracy Center 6903 Rockledge Drive Bethesda, MD 20817 Tel (301)564-3200 Fax. (301) 564-3201 Unitenl ales Enrichment Corporation February 24,1997 Mr. Randall M. DeVault Regulatory Oversight Manager US Department of Energy 3 Main Street Oak Ridge, Tennessee 37830
Dear Mr. DeVault:
United States Enrichment Corporation (USEC) - Portsmouth Gaseous Diffusion Pant (PORTS) - Docket No. 70-7002 - Proposed Resolution to Cell Treatment Coolant System Pressure The purpose of this letter is to request DOE review of proposed changes to the FSAR to resolve the cell treatment coolant system pressure issue.
In accordance with your letter dated January 15,1997 (RG-70-7002/97-0017), we have discussed the planned changes to the SAR/FSAR for resolving the cell treatment issue with the i
NRC. The enclosure to this letter outlines the proposed changes to S AR Section 4.1.1.2.2 (Case C-
)
13), FSAR Section 5.1.1.2.2 (Case C-13), and the Basis Statements for TSR Sections 2.2.3.5 and 2.7.3.4. The proposed FSAR changes outlined in the enclosure supersede those provided to you in our November 1,1996 letter.
A copy of the classified Unreviewed Safety Question Determination supporting the proposed changes to the FSAR is available at the site for review.
If you have any questions or require additional information on this subject, please call Mr.
Ron Gaston (614) 897-2710.
Sincerely, bU Robert L. Woolley
}hgg Nuclear Regulatory Assurance and Policy Manager 9702260447 970224 s
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PDR ADOCK 07007002 I
C PDR 260056 geqmy;&n4FcSS Offices in Paducah, Kentucky Portsmouth, Ohio Washington. DC
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Mr. Randall M. DeVault l
February 24,1997 Page Two
Enclosure:
SAR, FSAR, and TSR Basis Changes to Resolve Cell Treatment Coolant System i
Pressure Issue, RAC 97X0076 (RO) (2 pages total)
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DOE Site Safety Representative, PORTS Mr. R. C. Pierson, NRC NRC Resident Inspector-PORTS 2
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Enclosure to 2/24/97 Letter Page1of2 SAR, FSAR, and TSR Basis Changes to Resolve Cell Treatment Coolant System Pressure Issue RAC 97X0076 (RO)
The following changes will be made to the SAR, FSAR, and TSR Basis Statements to resolve the cell treatment coolant system pressure issue:
1.
FSAR Section 5.1.1.2.2, Case C-13, items 2,3, and 5 will be revised to read as follows:
2.
Removing all liquid coolant and evacuating the coolant system to limit the amount of coolant available for a reaction if there were a coolant leak. The vacuum requirement for the X-27 and X-29 size equipment is between 18 and 30 inches of Hg. The larger equipment has no specific requirement other than taking the system below atmosphere so that any pools ofliquid will vaporize and be removed.
3.
Periodic monitoring of the cell with an infrared analyzer to detect any coolant or fluorocarbons which would indicate a coolant leak or oil in the cell.
5.
Sampling the cell to assure presence of free ClF and avoid the formation of the more 3
reactive Cl which will react with the aluminum in the cell (AlCl). (See Section 2
3 5.1.1.8.2 for the oxidizing effects of CIF.) The probability of an exothermic reaction 3
in a cell during ClF treatment has been reduced to low because of improved 3
procedures.
2.
SAR Section 4.1.1.2.2, Case C-13, item 2 will be revised to read as follows:
2.
Removing all liquid coolant and evacuating the coolant system to limit the amount of coolant available for a reaction if there were a coolant leak The vacuum requirement for the X-27 and X-29 size equipment is between 18 and 30 inches of Hg. The larger equipment has no specific requirement other than taking the system below atmosphere so that any pools ofliquid will vaporize and be removed.
3.
The Basis Statement for TSR Section 2.2.3.5 will be revised to read as follows:
j Basis:
In the event of a leak from the coolant system to the process gas, the failure to control the concentrations of coolant and CIF /F within the cell can form explosive 3 2 mixtures that in the presence of an ignition source could over pressure the cell and 4
s.
' Enclosure to 2/24/97 Letter Page 2 of 2 SAR, FSAR, and TSR Basis Changes to Resolve Cell Treatment Coolant System Pressure Issue
. RAC 97X0076 (RO) release toxic materials.' The draining of coolant includes the evacuating of the~
coolant system to between 18 and 30 inches of Hg for the X-27 and X-29 size -
equipment.
The other equipment sizes-have no specific coolant evacuation requirement other than for the system pressure to be below atmospheric pressure.
The indications of an exothermic reaction are usually rapid pressure spikes and/or a rapid increase in temperature. A leaking block valve between a F/S that has a leaking cooler and the host cell could allow coolant and treatment gases to mix and therefore potentially form a highly exothermic reaction mixture [SAR 4.1.1.2.2 Case I
C-13].
4.'
The Basis Statement for TSR Section 2.7.3.4 will be revised to read as follows:
)
Basis:
In the event of a leak from the coolant system to the process gas,'the failure to control the concentrations of coolant and CIF /F within the cell can form explosive 3 2 mixtures that in the presence of an ignition source could over pressure the cell and
-I release toxic materials: The draining of coolant includes evacuating of the coolant system to between 18 and 30 inches of Hg for the X-27 and X-29 size equipment.
The other equipment sizes have no specific coolant evacuation requirement other than for the system pressure to be below atmospheric pressure. The indications of an exothermic reaction are usually rapid pressure spikes and/or a rapid increase in temperature [SAR 4.1.1.2.2 Case C-13].
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