ML20199J736
| ML20199J736 | |
| Person / Time | |
|---|---|
| Site: | Portsmouth Gaseous Diffusion Plant |
| Issue date: | 01/20/1999 |
| From: | Ting P NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | |
| Shared Package | |
| ML20199J726 | List: |
| References | |
| 70-7002-99-201, NUDOCS 9901260238 | |
| Download: ML20199J736 (6) | |
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U.S. NUCLEAR REGULATORY COMMISSION
. OFFICE OF NUCLEAR MATERIAL SAFETY AND SAFEGUARDS Docket No:
'70-7002 i
Certificate No:
GDP-2 l
Report No:
70-7002/99-201 i
Certificate Holder:
United States Enrichment Corporation Location:
Portsmouth Gaseous Diffusion Plant Piketon, Ohio Dates:
January 5-7,1999 Inspectors:
Garrett Smith, Inspector, NRC Headquarters David Hurley, Contractor, Battelle
.' Approved By:
Philip Ting, Chief, Operations Branch, Division of Fuel Cycle Safety and Safeguards, NMSS Enclosure 990126023e 990120?'
PDR ADOCK 0700
,.-,y 4
4 m.-
2 UNITED STATES ENRICHMENT CORPORATION PORTSMOUTH GASEOUS DIFFUSION PLANT NRC INSPECTION REPORT 70-7002/99-201 EXECUTIVE
SUMMARY
Areas inspected A Nuclear Regulatory Commission (NRC) Headquarters team conducted an announced Chemical Process Safety inspection of the Portsmouth Gaseous Diffusion Plant (PORTS) in Piketon, Ohio, on January 5-7,1999. The inspection was conducted using NRC Headquarters staff and a contractor. The inspection focused on PORTS high-risk chemical release possibilities that may occur as a result of a seismic initiating event.
Results e
Due to this facility's location in south central Ohio, the evaluation basis earthquake (EBE) was determined to be relatively low (0.05g). Based on the reviews and walk-downs performed during the inspection, the inspectors determined that the high-risk chemical facilities onsite (liquid uranium hexafluoride (UF ) and anhydrous hydrofluoric 6
acid (AHF)) would adequately withstand an EBE event.
REPORT DETAILS 1.0 Process Safety Information and Process Hazards Analysis - Seismic Initiatine Event a.
Scone of the Insnection The inspectors reviewed the use ud storage of high risk chemicals onsite (UF, and 6
AHF). Specifically, the systems were evaluated to determine the consequences of a 250 year return earthquake event. The inspectors reviewed the Process Safety Information and Process Hazard Analyses for these facilities and performed walk-downs of the areas to evaluate the likely effects of a seismic event.
b.
Obsen ations and Findines General Title 10 CFR 76.85, Assessment of Accidents, requires the certificate holder to perform an analysis of potential accidents and consequences to establish the basis for limiting conditions for operation of the plant with respect to the potential for plant releases of
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3 radioactive material. Additionally, the Statements of Consideration for Part 76 (59 FR 48944), published on September 23,1994, states that in assessing the adequacy of protection of the public health and safety from potential accidents, the NRC will consider whether the potential consequences of a accident exceed 25 rem, or a uranium intake of 30 milligrams, taking into account the uncertainties associated with the modeling. The Statements of Consideration for Part 76 also states that the NRC will evaluate the consequences of potential accidents resulting from natural phenomena (i.e., seismic event).
The EBE for the Portsmouth site was documented in the Beavers et al. study (1982) to have an estimated peak ground acceleration of 0.05g and a return period of 237 years.
This document summarized several seismic hazard studies that were perfomied for the Portsmouth facility. At the time, this evaluation determined that there was a 10-percent probability that the 0.05g value would be exceeded during the remaining life of the plant (25 years). As part of the Department of Energy Safety Analysis Report (SAR) upgrade program, this EBE has been revisited and based on this re-review has remained the same.
Currently, to support the SAR upgrade program, additional seismic analyses have been completed and submitted to the NRC. These analyses are currently being reviewed by the NRC. To support this inspection activity, the inspectors reviewed all of the available seismic information, but evaluated the seismic risk at the site against the requirements used as the safety basis for the existing NRC-approved SAR. These inspection activities were not in support of the SAR upgrade review.
Seismic Event Conseauences Once the EBE was determined for PORTS, the certificate holder next performed an evaluation on risk significant facilities, vessels, and piping to ensure that the EBE would not cause unacceptable releases of highly hazardous chemicals (defined by the regulations as an uranium intake of 30 milligrams). Although is was determined that a EBE of 0.05g was a relativity small event that would do very little damage to the facility, the certificate holder, as part of the SAR upgrade effort, had engineers evaluate the liquid UF systems 6
(highest UF. risk) to determine if any seismic vulnerabilities existed. This review indicated that portions of the piping, due to support conditions, had insufficient structural capacity to completely withstand the EBE. Since this preliminary review was based on design drawings and not an actual field inspection, further field inspection work was l
completed. After removing heated housings or using a boroscope to verify the actual conditions, the engineers added supports, as needed, to strengthen all of the equipment.
The inspectors walked down these systems and reviewed the documented results to verify the work was completed and the system upgrades were adequate.
s Additionally, the inspectors performed a walk-down of the highest pure chemical hazards (that could, if released during a seismic event, affect the safe handling of the special i
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nuclear material) to determine if the EBE would cause catastrophic damage and/or releases. Specitically, the inspectors toured the AliF facility where the licensee stores and handles 800-pound cylinders ofliquid AHF. The AHF is vaporized and converted to fluorine gas for storage and use onsite. These 3.5-fhot diameter cylinders are stored on sturdy, low-profile dol'ies and are chained to the wall. Based on the review of these cylinders and all of the AHF and fluorine systems, the inspectors determined that the risk associated with the dBE would be low.
i c.
Conclusions Due to this facility's location in south central Ohio, the EBE was determined to be relatively low (0.05g). Based on the reviews and walk-downs performed during the i
inspection, the inspectors determined that the high-risk chemical facilities onsite (liquid
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UF. and AHF) would adequately withstand EBE event.
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l 2.0 Management Meetings The inspectors met with USEC management periodically during the inspection. The inspectors presented the inspection scope and findings to members of USEC's staff at the conclusion of the inspection on January 7,1999. USEC acknowledged the findings presented at the meeting.
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5 ITEMS OPENED. CLOSED. OR DISCUSSED None.
4 PARTIAL LIST OF PERSONS CONTACTED 1
i Lockheed-Martin Utility Services J. M. Brown Ed Wagner J. B. Morgan
' Sandy Fout.
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Ron Smith M. B. Wayland Charly Blackston Peter Miner Pete Hopkins l
l HRC Comtney Blanchard, Resident Inspector Garrett Smith, Chemical Safety inspector David Hurley, PhWL l
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j ACRONYMS USED l
AHF Anhydrous Hydrofluoric Acid l
EBE Evaluation Basis Earthquake NRC Nuclear Regulatory Commission PSI Process Safety Analysis l
SAR Safety Analysis Report UF.
Uranium liexafluoride DOCUMENTS REVIEWED l
K/BD-1025," Recommended Seismic Ilazard Levels for the Oak Ridge, Tennessee; l
Paducah, Kentucky; Fernald, Ohio; and Portsmouth, Ohio, Department of Energy Reservations," April 1982 POEF-830-97-003, " Preplanning for Seismic Modifications to Selected Cascade Piping Systems," February 14,1997 POEF-814-98-079,"ESO E1625 RESOLUTION - Withdrawal tation Inspections For Seismic Outliers," July 7,1998 DOE-STD-1020-94," Natural Phenomena IIazards Design and Evaluation Criteria for Department of Energy Facilities," Change Notice #1, January 1996 l
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