ML20132E150
| ML20132E150 | |
| Person / Time | |
|---|---|
| Site: | Portsmouth Gaseous Diffusion Plant |
| Issue date: | 12/13/1996 |
| From: | John Miller UNITED STATES ENRICHMENT CORP. (USEC) |
| To: | Paperiello C NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| GDP-96-0198, GDP-96-198, TAC-L32006, NUDOCS 9612230071 | |
| Download: ML20132E150 (3) | |
Text
United St:t;s Enrichm;ntCorpor tion 2 Democracy Center
.T 6903 nockiedoe Drive Bethesda, MD 20817 Tel: (301)564-3200 Fax:(301) 564-3201 JAMES H. MILLER Dir: (301) 564-3309 VICE PRESIDENT, PRODUCTION tix: (301) 571-8279 December 13,1996 Dr. Carl J. Paperiello SERIAL: GDP 96-0198 Director, Office of Nuclear Material Safety and Safeguards Attention: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Portsmouth Gaseous Diffusion Plant (PORTS)
Docket No. 70-7002 Response To Request for AdditionalInformation Certificate Amendment Request-Withdrawal Stations Standby Operational Mode
Dear Dr. Paperiello:
The purpose of this letter is to provide a response to your request (TAC. No. L32006) for additional information on the Certificate Amendment Request (CAR) dealing with the Withdrawal Stations Standby Operational Mode. This additional information request was provided to USEC in Reference I and states that information was not provided in the CAR to address criticality safety, without which the NRC staffis unable to conclude that there would be no reduction in safety for the facility in granting the requested change.
Although the addtional infonnation request did not identify a specific question related to criticality safety, based on a telephone conversation between USEC and Mr. Yawar Faraz of your staff on November 25,1996, it is USEC's understanding that the concern related to the potential for wet air inleakage into the cascade.
/
It is imponant to note that the venting of UF. from a withdrawal loop to the Cascade is a normal O
pan of the overall process to drain liquid UF into cylinders and to perform cylinder p
/
6 and purging necessary for the routine connection and disconnection as described in SAR Section 3.2.2.6 and analyzed as part of the withdrawal process in SAR Sections 4.2.2.2 and 4.2.3 (Table 4.2-5). The Certificate Amendment Request oes not involve a change to this analyzed operation but is I
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i i-Dr. Carl J. Paperiello December 13,1996 GDP 96-0198 Page 2 clarifying that valves interior to the withdrawal station piping boundary must be opened in order to I-connect the enrichment cascade to the compressor portion of the withdrawal loop during the period of time necessary to evacuate the UF from the compressors and their associated discharge and recycle 6
- piping prior to isolating the compressors and allowing them to operate on " recycle".
Allowing these interior valves to be opened does not increase the risk of wet air inleakage into
~
the withdrawal station or the enrichment cascade. The placing of the compression loop in " recycle" a
i does not involve the operation of any boundary valves that separate the Cascade or the condensing portion of the withdrawalloop from atmosphere and therefore does not increase the potential for any wet air inleakage. SAR Section 4.2.2.2, Criticality in Tails, ERP or Product Withdrawal Facilities l
addresses the overall concern of criticality at the withdrawal stations:
"The Product Withdrawals are designed with nuclearly safe geometries, so that accumulations of unsafe quantities of product-assay material are not credible during either normal operation or accident conditions...."
Any wet air inleakage via the withdrawal station would not be a criticality concern at the station l
due to system geometry and assay controls (TSRs 2.5.3.5,2.5.3.6 and 2.5.3.7). The formation of any l-UO F deposits would at most only cause operational problems due to flow restrictions.
2 2 Although not affected by the proposed CAR, the potential for any uncontrolled wet air inleakage j
via the pigtail / boundary valves, which was also a concern noted by your staff during the November 25,1996 telephone conversation, is extremely low. There are at least four boundary valves in series that would have to fail or not be operated in accordance with existing procedures in order to provide i
a path for wet air inleakage. In addition, should an unexpected and uncontrolled inleakage of wet air occur, a high pressure vent alarm is provided to indicate process perturbations and to notify _ the l
operator of the need for operator action.
1
. Any questions related to this subject should be directed to Mr. Robert L. Woolley at (301) 564-3413 or Mr. Mark Smith at (301) 564-3244.
Sincerely, aeets.1 ?/. M L *, [
James H. Miller Vice President, Production cc:
NRC Region III Office I
NRC Resident Inspector - PGDP NRC Resident Inspector - PORTS Mr. J. Dale Jackson (DOE) 4 d
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Dr. Carl J. Paperiello December 13,1996 GDP 96-0198 Page 3
' Reference
- 1) NRC Letter from Mr. Robert C. Pierson to Mr. James H. Miller, " Certificate Amendment Request-Portsmouth Gaseous Diffusion Plant Withdrawal Stations Standby Operational Mode (TAC No.
L32006)," dated November 29,1996.
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