ML20211D235
| ML20211D235 | |
| Person / Time | |
|---|---|
| Site: | Portsmouth Gaseous Diffusion Plant |
| Issue date: | 08/16/1999 |
| 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-99-0151, NUDOCS 9908260206 | |
| Download: ML20211D235 (3) | |
Text
i USEC A ci.6.i innsy comp.ny August 16,1999 GDP 99-0151 Dr. Carl J. Paperiello 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 Followup to Submittal Regarding Holdup of Uranium Enriched Greater Than or Equal to 10 Weight Percent "U in Process Equipment 2
INFORMATION TRANSMITTED HEREWITH IS PROTECTED FROM PUBLIC DISCLOSURE AS CONFIDENTIAL COMMERCIAL OR FINANCIAL INFORMATION AND/OR TRADE SECRETS PURSUANT TO 10 CFR 2.790 AND 9.17(A)(4)
Dear Dr. Paperiello:
This letter replaces letter number GDP 99-0133, which was issued on August 13,1999 with the wrong date, In a letter dated August 13,1998 (Reference 1), the United States Enrichment Corporation (USEC) submitted to the Nuclear Regulatory Commission (NRC), and by copy to the Department of Energy (DOE), information regarding the holdup of material enriched greater than or equal to 10 weight
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2 percent "U in process equipment. The NRC has requested additional information regarding this submittal, specifically updated holdup data for the X-326 cascade and the process that would be followed once a deposit is identified that could cause USEC to exceed its NRC possession limit.
USEC is performing a Caretaker Project for the Department of Energy (DOE) in X-326. The i
purpose of the Caretaker Project is to periodically monitor the shutdown cells in the X-326 cascade to assure material is not being diverted. The Caretaker measurements are performed every two years (plus DOE allowable interval extension). USEC recently completed a comparison of data from the l
DOE Highly Enriched Uranium (HEU) Suspension Project to data gathered for the Caretaker Project Q/
and the security sweeps that were done for the X-326 facility in 1998. This information is provided in Enclosure 1.
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Dr. Carl J. Paperiello August 16,1999 GDP 99-0151, Page 2 Both sets of data in Enclosure I were obtained using slab neutron nondestructive assay (NDA) detectors. The percentage bias given for each cell represents the difference between the Caretaker / security sweep value (denoted as " Sweep") and the HEU Suspension Project value (denoted as "HEU") divided by the HEU Suspension Project value times 100. Analysis of the data indicates that a slight overall bias, calculated as an average of individual cell bias, exists (-7.9%).
This bias is within the accuracy of the NDA instrumentation, as it is not credible that the deposits in shutdown cells have actually either increased or decreased over time as the values in Enclosure 1 may be interpreted to indicate. This determination is based upon the fact there is no process gas flow in the shutdown cells, nor have there been any indications or reports of diversion of material from these cells. The assay of deposits in the X-326 shutdown cells has not changed since the HEU Suspension Project measurements were completed.
l USEC has not provided updated data for the operating cells in X-326. Due to the dynamic 8
environment in operating cells, the size of deposits may increase or decrease due to changes in the cascade taper, amount of wet air inleakage, plant power level, cell pressure, etc. However, it is not I
credible that the assay of deposits could increase over those provided to the NRC in Reference 1.
The flow of UF. through the cascade can only contain up to 10 weight percent "U, therefore the 2
cascade flow could not cause the assay of any deposit to grow beyond 10 weight percent "U even 2
with wet air inleakage. Any material greater than or equal to 10 weight percent "U in existing 2
deposits that transferred from the solid to the gaseous phase would be diluted essentially immediately by the process gas flow and, therefore, could not increase the assay of other existing deposits beyond 10 weight percent "U. Therefore, the operating cell information provided to the 2
NRC in Reference I should be adequate for the purposes of resolving the holdup issue and does not require updating.
1 i
USEC is providing in Enclosure 2 a revised sequence of the activities undertaken once it is determined that a component at PORTS contains deposits that could cause USEC to exceed its i
NRC possession limits (as defined in Table 1-3 of the Safety Analysis Report) and is identified for removal. This sequence was avised from that provided in Enclosure 6 to Reference 1, and completely replaces the sequence provided in Enclosure 6 to Reference 1. Once NRC and DOE approval of the approach outlined in Enclosure 2 is obtained, USEC will incorporate the process described in Enclosure 2 into plant procedures.
As stated in Reference 1, USEC understands that, even though data has been provided to the NRC for cells that are controlled by the DOE, the NRC will not assume regulatoryjurisdiction over any material that is located in areas that are controlled by the DOE (e.g., DMSA-12). It is USEC's understanding that the NRC would have regulatory jurisdiction to ensure that all diffuse and inaccessible uranium enriched greater than or equal to 10 weight percent "U remains in installed 2
equipment in USEC-leased and NRC-certified areas and remains inaccessible. USEC further understands that DOE would have regulatory jurisdiction for all material enriched greater than or i
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Dr. Carl J. Paperiello August,16,1999 i
GDP 99-0151, Page 3 235 equal to 10 weight percent U which is accessible or contained in uninstalled equipment, and also l
over the removal ofinstalled equipment containing such material. The DOE cegulatoryjurisdiction of these activities in USEC-leased space will be in accordance with the DOE /USEC Regulatory l
Oversight Agreement (ROA).
USEC requests that the NRC provide confirmation to USEC that the approach described in this letter is acceptable to NRC.
Enclosures 1,2, and 3 of this submittal contain confidential commercial or financial information or i
trade secrets that are exempt from public disclosure pursuant to Section 1314 of the Atomic Energy Act of 1954, as amended, and 10 CFR 2.790 and 9.17(a)(4). USEC requests that Enclosures 1,2, and 3 of this submittal be withheld from public disclosure. The affidavit provided in Reference I contains the information required by 10 CFR 2.790(b)(4) with respect to this request.
Commitments made in this submittal are contained in Enclosure 3. These commitments completely replace the commitments provided in Enclosure 10 to Reference 1. Any questions related to this subject should be directed to Mark Lombard at (301) 564-3248.
- Sincerely,
$.ks h 0
Steven A. Toelle Nuclear Regulatory Assurance and Policy Manager
References:
- 1. Letter from Steven A. Toelle (USEC) to Carl J. Paperiello (NRC), " Holdup of 235 Uranium Enriched to Greater Than 10 Weight Percent U in Process Equipment,"
GDP 98-0177, August 13,1998.
Enclosures:
- 2. Sequence of Activities Undertaken Once a Component is Identified for Removal That Contains Deposits That Could Cause USEC to Exceed NRC Possession Limits
- 3. Commitments Contained in This Submittal cc: Robert C. Pierson, NRC HQ Patrick L. Hiland, NRC Region III David Hartland, NRC PORTS Kenneth O'Brien, NRC PGDP