ML20237B516
| ML20237B516 | |
| Person / Time | |
|---|---|
| Site: | Paducah Gaseous Diffusion Plant |
| Issue date: | 08/12/1998 |
| From: | Toelle S UNITED STATES ENRICHMENT CORP. (USEC) |
| To: | Paperiello C NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| GDP-98-0174, GDP-98-174, TAC-L32082, NUDOCS 9808180356 | |
| Download: ML20237B516 (3) | |
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.j USEC A Global Energy Company August 12,1998 I
GDP 98-0174
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Dr. Carl J. Paperiello I
Director, Office of Nuclear Material Safety and Safeguards j
Attention: Document Control Desk l
U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Paducah Gascous Diffusion Plant (PGDP)
Docket No. 70-7001 Response to Request for Additional Information - Certificate Amendment Request - TSR 2.2.4.13, Autoclave Manual Isolation System (TAC No. L32082)
Dear Dr. Paperiello:
The purpose of this letter is to provide a response to the NRC's request (TAC No. L32082) for additional information on the Certificate Amendment Request (CAR) dealing with revision of Technical Safety Requirement (TSR) 2.2.4.13, Autoclave Manual Isolation System. The request for additional information was provided to USEC in Reference 1 and identified additional information required by NRC to allow final action to be taken on the subject Certificate Amendment Request. to this letter provides USEC's response to the request for additional information.
Should you have any questions related to this subject, please contact Mark Smith at (301) 564-3244.
There are no new commitments contained in this submittal.
Sincerely,
(
S. A.
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Steven A. Toelle Nuclear Regulatory Assurance and Policy. Manager
Enclosures:
- 1. Response to Request for Additional Information, Autoclave Manual Isolation System, TSR 2.2.4.13 cc: Mr. Robert C. Pierson, NRC NRC Region III Office NRC Resident Inspector - PGDP NRC Resident Inspector-PORTS Mr. Randall M. DeVault, DOE 9808180356 900812
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s Telephone 301564 3200 Fax 301564-3201 httpd/www.usec.com
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Offices in Livermore, CA Paducah. KY Portsmouth, OH Washinpon. DC o-i
Dr., Carl L., Paperiello August 12',1998 GDP 98-0174, Page 2 References
- 1.
Letter from Merri llorn (NRC) to James II. Miller (USEC), Paducah Certificate Amendment Request - TSR 2.2.4.13 (TAC No. L32082), dated July 9,1998.
2.
Letter from James H. Miller (USEC) to Dr. Carl Paperiello (NRC), Certificate Amendment Request - Autoclave Manual isolation System - TSR 2.2.4.13, USEC Letter GDP 98-0092, May 29,1998.
3.
Letter from James II. Miller (USEC) to Dr. Carl Paperiello (NRC), Response To Request for Additional Information, Certificate Amendment Request - Autoclave Manual Isolation System, USEC Letter GDP 97-0016, February 14,1997.
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GDP 98-0174 Page1of1 l Response to Request for AdditionalInformation (TAC No. L32082)
Autoclave Manual Isolation System TSR 2.2.4.13 Ouestion 1 q
The Required Actions under new Condition E would allow operation of the feed facilities with only 1 of the actuation devices being operable for a period of up to 30 days. Please provide additional justification for why this time period is appropriate.
Resoonse TSR Required Action Completion Times were selected commensurate with importance to safety.
The Autoclave Manual isolation System (AMIS) has less safety significance than other TSR systems associated with the autoclaves. This is due to the fact that the purpose of the AMIS is to limit a potential gaseous UF release due to a line break outside the autoclave, while the other systems 6
prevent, or mitigate the consequences of, the rupture of a liquid cylinder inside an autoclave. Unlike the other systems, limiting the gaseous release due to a piping failure outside an autoclave is not required in order to validate the accident analysis assumptions or requirements. The accident analysis considers the gaseous release scenario due to a line break outside an autoclave but the offsite consequences of such an event are not significant.
The required actions were selected such that, in the event of inoperability of either one or two actuation devices, the capability to immediately actuate at least one pull button is assured. The most important actuation devices are those located at the feed facility. As noted in the basis statement of the TSR, the system is designed to provide for a means to isolate the autoclaves (and thereby isolate the source of the release) by the feed facility operators as they exit the feed facility in accordance with the "see and flee" policy. The ACR button is provided as a backup in the event that both feed facility buttons are inoperable. The use of the ACR button is of primary importance when implementing Required Action D.3.1. In the event that one of the local buttons is inoperable, the safety function is assured by implementation of Required Action A.1 or B.1, regardless of the status of the ACR button.
Since the safety function is assured, and the safety function is not required to prevent or mitigate the consequences of a significant offsite release, the selection of 30 days is considered appropriate and commensurate with safety significance.
Ouestion 2 The Basis should also be revised to make clear that the functional test includes testing of all three actuation devices.
Resoonse The basis statement and the surveillance requirement were previously revised to require that the functional test include all three actuation devices in USEC's response to TAC L32003, Ca;stion 2 (see Reference 3.)
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