United States Nuclear Regulatory Commission - Protecting People and the Environment

EA-98-156 - U. S. Enrichment Corporation

April 22, 1998

EA 98-156

Mr. James H. Miller
Vice President, Production
U. S. Enrichment Corporation
2 Democracy Center
6903 Rockledge Drive
Bethesda, MD 20817

SUBJECT: CONFIRMATORY ORDER MODIFYING CERTIFICATE FOR THE PADUCAH GASEOUS DIFFUSION PLANT

Dear Mr. Miller:

Based on the Nuclear Regulatory Commission's (NRC) review of a certificate amendment request dated October 31, 1997, submitted by the Corporation, the NRC has concluded that a violation of NRC requirements occurred. The violation involved a failure to perform an analysis of potential accidents (10 CFR 76.85) and a failure to comply with the conditions of certification (10 CFR 76.51).

The enclosed Order is being issued to confirm your commitments to install seismic modifications in the C-310/310A and C-315 Buildings at the Paducah Gaseous Diffusion Plant (Paducah) by no later than September 30, 1998. That action is required to bring those facilities back into compliance with the Paducah Safety Analysis Report. The modifications will increase the seismic capacity of the equipment in the facilities to withstand an earthquake producing a peak ground acceleration of 0.165 g. until the modifications are completed, operations in the C-310/310A and C-315 Buildings will have restrictions imposed by Condition 13 of the Paducah Certificate of Compliance as modified by the enclosed Order. Your letter dated April 1, 1998, provided your signed agreement to incorporating these commitments into a Confirmatory Order Modifying Certificate, to be effective upon issuance.

Pursuant to section 223 of the Atomic Energy Act of 1954, as amended, any person who willfully violates, attempts to violate, or conspires to violate, any provision of this Order shall be subject to criminal prosecution as set forth in that section. Violation of this order may also subject the person to a civil monetary penalty.

Issuance of this Order does not preclude the NRC from issuing additional enforcement action.

Questions concerning this Order should be addressed to me and I can be reached at (301) 415-2741. In accordance with 10 CFR 2.790 of the NRC's "Rules of Practice," a copy of this letter and its enclosure will be placed in the NRC Public Document Room.

Sincerely,




James Lieberman, Director
Office of Enforcement

Docket No. 70-7001
Certificate No. GDP-1

Enclosure: As stated


UNITED STATES

NUCLEAR REGULATORY COMMISSION

In the Matter of

UNITED STATES ENRICHMENT
CORPORATION
Bethesda, Maryland
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Docket No. 70-7001
Certificate No. GDP-1
EA 98-156

CONFIRMATORY ORDER MODIFYING CERTIFICATE

(EFFECTIVE IMMEDIATELY)

I

United States Enrichment Corporation (Corporation) is the holder of Certificate No. GDP-1 issued by the Nuclear Regulatory Commission (NRC or Commission) pursuant to 10 CFR Part 76. The certificate authorizes the Corporation to operate the Paducah Gaseous Diffusion Plant (Paducah) for the purpose of enriching uranium up to 2.75 percent 235U by weight. The certificate, originally issued on November 26, 1996, is due to expire on December 31, 1998.

II

Since transition to NRC regulatory oversight on March 3, 1997, the Corporation has been operating its withdrawal facilities (Buildings C-310/310A and C-315) with liquid uranium hexafluoride (UF6) inventories in process piping, condensers, and accumulators. The certificate conditions placed no restrictions on those inventories, thereby allowing the accumulators to contain any amount up to their full capacity. A certificate amendment request dated October 31, 1997, submitted by the Corporation, requested an update to the Safety Analysis Report (SAR) to include a new Chapter 4, "Accident Analysis." An NRC request for additional information (RAI) dated February 5, 1998, identified questions about the conservative nature of assumptions for the seismic accident scenario in Chapter 4. In response to the RAI, the Corporation reviewed Paducah's liquid UF6 withdrawal facilities' records and determined that the seismic accident analysis assumption of no liquid UF6 in both facilities' accumulators underestimated the potential source term from the withdrawal facilities for the seismic accident scenario. In telephone discussions with the NRC on February 18, 1998, the NRC made it clear to the Corporation that a notification pursuant to 10 CFR 76.9(b) was warranted. Thereafter, the Corporation provided verbal notification to NRC Region III on February 19, 1998, and a follow-up written report on February 20, 1998, identifying the potential nonconservative assumption in the SAR updated accident analysis. Then, on February 24, 1998, in telephone discussions with NRC, the Corporation also provided information that the withdrawal facilities' current operations were outside the Certification SAR because the Chapter 4 seismic accident analysis assumed no liquid UF6 in Building C-315 withdrawal facility's process piping, condensers, and accumulators. In addition, the source term from Building C-310/310A was probably too low.

Based on the NRC's review of the certificate amendment request dated October 31, 1997, submitted by the Corporation and the current Certification SAR, the NRC has concluded that violations of NRC requirements occurred. The violations involve an inadequate accident analysis and a failure to comply with the conditions of certification. The Commission's regulations in 10 CFR 76.85 require the Corporation, as the certificate holder, to perform an analysis of potential accidents and consequences to establish the basis for limiting conditions for operations and to provide assurance that plant operation will be conducted in a manner to prevent or to mitigate the consequences from a reasonable spectrum of postulated accidents, including natural phenomena. Further, 10 CFR 76.85 requires that the assessment consider the full range of operations, including operations at the maximum capacity contemplated. The Commission's regulations in 10 CFR 76.51 require the Corporation, as the certificate holder, to comply with the conditions set forth in the Certificate of Compliance. Condition 8 of the Certificate of Compliance (GDP-1) for the Paducah Gaseous Diffusion Plant requires the Corporation to conduct its operations in accordance with the statements and representations contained in the certification application and subsequent amendments. The certification application includes Safety Analysis Report (SAR) Chapter 4, "Accident Analysis," Section 4.6, "Natural Phenomena," describing assumptions made on facility operations to determine the consequences of postulated seismically-induced failures. The Chapter 4 seismic accident analysis is based on an inappropriately low assumption of the amount of liquid UF6 in Buildings C-310/310A and C-315 withdrawal facilities' process piping, condensers, and accumulators in calculating the possible releases. Current facility configuration and operations are such that significantly higher volumes (on the order of several thousand pounds (lbs)) of liquid UF6 may be present. Therefore the accident analysis in the Certification SAR is not in compliance with 10 CFR 76.85 and operation of that facility is not in compliance with Condition 8. Furthermore, operation with the larger amount of liquid UF6 in the withdrawal facilities is safety significant because failure could result in potential on-site fatalities/injuries and off-site injuries. During a seismic event of 0.05 g peak ground acceleration, failure of equipment in both withdrawal facilities would likely occur with releases of liquid UF6. If the 0.05 g seismic event occurred with substantial amounts of liquid UF6 in those facilities, the on-site and off-site consequences would exceed any analyzed accident and be unacceptable.

III

By letter dated February 25, 1998, the Corporation committed to implement the administrative control as stated below:

1. Access to Buildings C-310/310A and C-315 will be limited to only those individuals essential to operations, inspections, or those personnel performing any modifications to fix the identified seismic failures.

By letter dated March 5, 1998, the Corporation committed to implement the following additional administrative controls in order to mitigate the consequences of a seismic event:

2. When flow of liquid UF6 has been diverted to the on-line accumulator in C-310A or C-315 for greater than one hour (nominal 2,000 and 5,000 lbs liquid UF6, respectively, at one hour), the Corporation will take the following immediate actions:

a. Notify the Plant Shift Superintendent (PSS) of accumulator usage.
b. Begin tracking of quantities by using calculated withdrawal rates.
c. The PSS will initiate high priority actions for timely resolution of unscheduled outages.
d. The Cascade Coordinator will take actions to reduce tails downflow and/or product or tails withdrawal rates to minimize accumulator use as appropriate.
e. Notify the NRC.

3. If the calculated accumulator inventory reaches 4,000 lbs liquid UF6 in C-310A or 10,000 lbs liquid UF6 in C-315, flow of liquid UF6 to the affected accumulator will be stopped immediately.

By letter dated March 11, 1998, the Corporation proposed to install seismic modifications to the equipment in Buildings C-310/310A and C-315 by September 30, 1998. Those seismic modifications will increase the seismic capacity of the equipment to withstand an earthquake producing a peak ground acceleration of 0.165 g.

I find that the Corporation's commitments to install the seismic modification within the proposed time frame and these administrative controls acceptable and necessary and conclude that with these commitments the public health and safety are reasonably assured. In view of the foregoing, I have determined that the public health and safety require that the Corporation's commitments be confirmed by this Order. By letter dated, April 1, 1998, the Corporation consented to the issuance of this Order confirming its commitments, as described in Section IV below. The Corporation further agreed in that letter that this Order is to be effective upon issuance. Implementation of these commitments will minimize the available liquid UF6 inventories that could be released in a seismic event and reduce the on-site and off-site consequences. Based upon the above and the Corporation's consent, this Order is immediately effective upon issuance.

IV

Accordingly, pursuant to sections 161b, 161i, 161o, and 1701 of the Atomic Energy Act of 1954, as amended, and the Commission's regulations in 10 CFR Part 76, including specifically 10 CFR 76.70, IT IS HEREBY ORDERED, EFFECTIVE IMMEDIATELY, THAT CERTIFICATE NO. GDP-1 IS MODIFIED AS FOLLOWS:

Condition 13 is added to the Certificate of Compliance GDP-1 to require that:

1. The Corporation will by no later than September 30, 1998, complete seismic modifications to the equipment containing liquid UF6 in Buildings C-310/310A and C-315. Those seismic modifications will increase the seismic capacity of the equipment to withstand an earthquake producing a peak ground acceleration of 0.165 g.

2. Until such time as the above seismic modifications are completed, the following additional administrative controls shall be followed:

a. When flow of liquid UF6 has been diverted to the on-line accumulator in C-310A or C-315 for greater than one hour (nominal 2,000 and 5,000 pounds (lbs) liquid UF6 respectively at one hour), the Corporation will immediately:

I. Notify the Plant Shift Superintendent (PSS) of accumulator usage.

ii. Begin tracking of quantities by using calculated withdrawal rates.

iii. Ensure that the PSS will initiate high priority actions for timely resolution of unscheduled outages.

iv. Ensure that the Cascade Coordinator will take actions to reduce tails downflow and/or product or tails withdrawal rates to minimize accumulator use as appropriate.

v. Notify the NRC.

b. If the calculated accumulator inventory reaches 4,000 lbs liquid UF6 in C-310A or 10,000 lbs liquid UF6 in C-315, flow of liquid UF6 to the affected accumulator will be stopped immediately.

c. Access to Buildings C-310/310A and C-315 will be limited to only those individuals essential to operations, inspections, or those personnel performing any modifications to fix the identified seismic failures.

The Director, Office of Enforcement, may, in writing, relax or rescind this Order upon demonstration by the Corporation of good cause.

V

Any person adversely affected by this Confirmatory Order, other than the Corporation, may submit a written response within 20 days of its issuance. Where good cause is shown, consideration will be given to extending the time to respond. A request for extension of time must be made in writing to the Director, Office of Nuclear Material Safety and Safeguards, U.S. Nuclear Regulatory Commission, Washington, D.C. 20555, and include a statement of good cause for the extension. Any response shall be submitted to the Secretary, U.S. Nuclear Regulatory Commission, ATTN: Chief, Rulemaking and Adjudications Staff, Washington, D.C. 20555. Copies of the response shall also be sent to the Director, Office of Enforcement, U.S. Nuclear Regulatory Commission, Washington, D.C. 20555, to the Deputy Assistant General Counsel for Enforcement at the same address, to the Regional Administrator, NRC Region III, 801 Warrenville Road, Lisle, Illinois 60532-4351, and to the Corporation.

In the absence of any response, or written approval of an extension of time in which to respond, the provisions specified in Section IV above shall be final 20 days from the date of this Order without further order or proceedings. If an extension of time for submitting a response has been approved, the provisions specified in Section IV shall be final when the extension expires if a response is not received. If a written response is received, the Commission may make a final decision or may adopt by order further procedures for consideration of the issues before making a final enforcement decision. WRITTEN RESPONSES SHALL NOT STAY THE IMMEDIATE EFFECTIVENESS OF THIS ORDER.

FOR THE NUCLEAR REGULATORY COMMISSION




James Lieberman, Director
Office of Enforcement

Dated at Rockville, Maryland
this 22nd day of April 1998

 

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