ML060930589
| ML060930589 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 03/31/2006 |
| From: | Casto C Division Reactor Projects II |
| To: | Brandi Hamilton Duke Energy Corp |
| References | |
| EA-06-070 IR-06-012 | |
| Download: ML060930589 (6) | |
See also: IR 05000269/2006012
Text
DOCUMENT TRANSMITTED HEREWITH CONTAINS OFFICIAL USE ONLY - PROPRIETARY
INFORMATION. WHEN SEPARATED FROM THE ENCLOSURE, THIS DOCUMENT IS
DECONTROLLED.
OFFICIAL USE ONLY - PROPRIETARY INFORMATION
March 31, 2006
Duke Energy Corporation (DEC)
ATTN: Mr. B. Hamilton
Site Vice President
Oconee Nuclear Station
7800 Rochester Highway
Seneca, SC 29672
SUBJECT:
OCONEE NUCLEAR STATION - NRC INSPECTION REPORT NOS.
05000269/2006012, 05000270/2006012, AND 05000287/2006012;
PRELIMINARY GREATER THAN GREEN FINDING
Dear Mr. Hamilton:
This letter and the enclosed supporting documentation discuss a finding that appears to have
greater than very low safety significance. Initially identified as unresolved item (URI)
05000269,270,287/2005004-07 in Section 4OA2.4 of NRC Integrated Inspection Report No.
05000269,270,287/2005004, issued on October 28, 2005, this finding concerns the apparent
untimely corrective actions in resolving east penetration room blowout panel-related
deficiencies for all three Oconee Units.
Specifically, in the late 1980's or early 1990's the upper and lower east penetration room
blowout panels were improperly modified (i.e., epoxied and fastened in place). The
modification caused the pressure relief point of the panels to be considerably greater than the
63 pounds per square foot licensing basis, and resulted in the flood mitigation panels (lower)
not being assured of opening to prevent auxiliary building flooding. This was identified as non-
cited violation 05000269,270,287/2002004-02 in Section 4OA5 of NRC Integrated Inspection
Report No. 05000269,270,287/2002004, issued on October 28, 2002. During a subsequent
presentation to the NRC in 2004, DEC indicated that modifications were necessary to prevent
flooding of the auxiliary building because the east penetration room doors and block walls would
likely fail during a high energy line break (HELB) and the blowout panels were not assured of
opening. The proposed modifications included installation of flood impoundment features to
contain the break flow, and installation of new blowout panels/flood outlet devices. However, as
discussed under unresolved item (URI) 05000269,270,287/2005004-07, DEC had not
developed any modifications or a schedule as of September 2005 for bringing the three units
OFFICIAL USE ONLY - PROPRIETARY INFORMATION
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DOCUMENT TRANSMITTED HEREWITH CONTAINS OFFICIAL USE ONLY - PROPRIETARY
INFORMATION. WHEN SEPARATED FROM THE ENCLOSURE, THIS DOCUMENT IS
DECONTROLLED.
back into compliance with the licensing basis. Consequently, as a result of the inappropriate
panel modifications, in conjunction with the inappropriate addition of floor curbing and the
inadequate strength of internal doors and block walls (all identified in 2001 Problem
Investigation Process report (PIP) O-01-00815), Units 1, 2, and 3 continue to be operated
outside their licensing basis with respect to HELB-related flood mitigation in the auxiliary
building. Therefore, it has been concluded that adequate corrective actions have not been
taken to promptly resolve the aforementioned HELB-related concerns with the east penetration
room blowout panels for all three Oconee Units.
This finding was assessed based on the best available information, including influential
assumptions, using the applicable Significance Determination Process (SDP) and was
preliminarily determined to be a Greater Than Green Finding. Enclosed is a summary of the
SDP Phase 3 analysis. The finding has a potentially greater than very low safety significance
because, instead of directing potential HELB-related flood water out properly operating blowout
panels, the existing condition would allow flood waters to egress down into the auxiliary building
and significantly impact the high pressure injection (HPI) pumps.
Although feedwater line break frequency was quantitatively determined, the NRC staff
conducted a qualitative evaluation of the risk based on the assumed HELB-related flooding loss
of HPI and the potential unavailability of emergency feedwater (EFW) due to HELB-related
effects (e.g., flooding, impingement, steam environment, etc..). As such, the evaluation
considered the numerous ways EFW availability/recovery could be impacted, and concluded
that a one in ten chance of failure of EFW would result in a Greater Than Green finding.
The finding is also an apparent violation (AV) of 10 CFR Part 50, Appendix B, Criteria XVI,
Corrective Action, for failure to promptly identify and correct this significant condition adverse to
quality. Specifically, as a result of inappropriate east penetration room blowout panel
modifications (identified as a violation in 2002), in conjunction with the inappropriate addition of
floor curbing and the inadequate strength of internal doors and block walls (all identified in
DECs corrective action program in 2001), Units 1, 2, and 3 continue to be operated outside
their licensing basis with respect to HELB-related flood mitigation in the auxiliary building. This
apparent violation (identified as AV 05000269,270,287/2006012-01: Failure to Promptly Correct
Long-Standing East Penetration Room Blowout Panel-Related Deficiencies That Preclude
Flood Mitigation in the Auxiliary Building) is being considered for escalated enforcement action
in accordance with the NRC Enforcement Policy). Accordingly, for administrative purposes,
URI 05000269,270,287/2005004-07 is considered closed.
In addition to the apparent violation discussed above, a related apparent violation of 10 CFR 50.73, Part (v) was identified for the failure to report that east penetration room blowout panel-
related deficiencies would prevent the fulfillment of the HPI system safety function to mitigate
the consequences of a HELB (i.e., to shutdown the reactor and maintain it in a cold shutdown
condition). This issue was initially identified as URI 05000269,270,287/2005004-08 in Section
4OA2.5 of NRC Integrated Inspection Report No. 05000269,270,287/2005004. A failure to
OFFICIAL USE ONLY - PROPRIETARY INFORMATION
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DOCUMENT TRANSMITTED HEREWITH CONTAINS OFFICIAL USE ONLY - PROPRIETARY
INFORMATION. WHEN SEPARATED FROM THE ENCLOSURE, THIS DOCUMENT IS
DECONTROLLED.
report could impact the NRCs ability for oversight of licensed activities. As such, its
significance was not evaluated through the SDP, but rather was evaluated in accordance with
the guidance in Section IV.A.3 of the NRC Enforcement Policy. Because its safety significance
is low and the particular regulatory process was not significantly impeded, this apparent
violation (identified as AV 05000269,270,287/2006012-02: Failure to Report East Penetration
Room Blowout Panel-Related Deficiencies Would Prevent Fulfillment of the HPI System Safety
Function) is currently not being considered for escalated enforcement. Accordingly, for
administrative purposes, URI 05000269,270,287/2005004-08 is considered closed. The
current Enforcement Policy is included on the Nuclear Regulatory Commissions website at
http://www.nrc.gov/reading-rm/adams.html.
In accordance with Inspection Manual Chapter (IMC) 0609, we intend to complete our
evaluation using the best available information and issue our final determination of safety
significance within 90 days of this letter. The significance determination process encourages
an open dialog between the staff and the licensee; however, the dialogue should not impact the
timeliness of the staffs final determination. Before we make a final decision on this matter, we
are providing you an opportunity to: (1) present to the NRC your perspectives on the facts and
assumptions, used by the NRC to arrive at the finding and its significance, at a Regulatory
Conference or (2) submit your position on the finding to the NRC in writing. If you request a
Regulatory Conference, it should be held within 30 days of the receipt of this letter and we
encourage you to submit supporting documentation at least 1 week prior to the conference in
an effort to make the conference more efficient and effective. If a Regulatory Conference is
held, it will be open for public observation. The NRC will also issue a press release to
announce the conference. If you decide to submit only a written response, such a submittal
should be sent to the NRC within 30 days of the receipt of this letter.
Please contact Mr. D. Charles Payne at (404) 562-4540 within 10 business days of the date of
your receipt of this letter to notify the NRC of your intentions. If we have not heard from you
within 10 days, we will continue with our significance determination and enforcement decisions
and you will be advised by separate correspondence of the results of our deliberations on this
matter.
Since the NRC has not made a final determination in this matter, a Notice of Violation is not
being issued at this time. In addition, please be advised that the number and characterization
of the apparent violations may change as a result of further NRC review.
In accordance with 10 CFR 2.390 of the NRC's "Rules of Practice," a copy of this letter and
your response (if any) will be available electronically for public inspection in the
OFFICIAL USE ONLY - PROPRIETARY INFORMATION
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DOCUMENT TRANSMITTED HEREWITH CONTAINS OFFICIAL USE ONLY - PROPRIETARY
INFORMATION. WHEN SEPARATED FROM THE ENCLOSURE, THIS DOCUMENT IS
DECONTROLLED.
NRC Public Document Room or from the Publicly Available Records (PARS) component of
NRCs document system (ADAMS). ADAMS is accessible from the NRC web site at
http://www.nrc.gov/reading-rm/adams.html (the Public Electronic Reading Room).
Sincerely,
/RA/
Charles Casto, Director
Division of Reactor Projects
Docket Nos.: 50-269, 50-270, 50-287
License Nos.: DPR-38, DPR-47, DPR-55
Enclosure:
SDP Phase 3 Summary (OFFICIAL USE ONLY -
PROPRIETARY INFORMATION)
OFFICIAL USE ONLY - PROPRIETARY INFORMATION
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DOCUMENT TRANSMITTED HEREWITH CONTAINS OFFICIAL USE ONLY - PROPRIETARY
INFORMATION. WHEN SEPARATED FROM THE ENCLOSURE, THIS DOCUMENT IS
DECONTROLLED.
cc w/encl:
N. Clarkson
Compliance Manager (ONS)
Duke Energy Corporation
Electronic Mail Distribution
Lisa Vaughn
Associate General Counsel
Duke Energy Corporation
526 South Church Street
Mail Code EC 07H
Charlotte, NC 28202
Henry J. Porter, Assistant Director
Div. of Radioactive Waste Mgmt.
S. C. Department of Health and
Environmental Control
Electronic Mail Distribution
cc w/o encl:
Timika Shafeek-Horton
Assistant General Counsel
Duke Energy Corporation
526 South Church Street-EC07H
Charlotte, NC 28202
David A. Repka
Winston & Strawn LLP
Electronic Mail Distribution
Beverly Hall, Acting Director
Division of Radiation Protection
N. C. Department of Environmental
Health & Natural Resources
Electronic Mail Distribution
R. Mike Gandy
Division of Radioactive Waste Mgmt.
S. C. Department of Health and
Environmental Control
Electronic Mail Distribution
County Supervisor of
Oconee County
415 S. Pine Street
Walhalla, SC 29691-2145
Lyle Graber, LIS
NUS Corporation
Electronic Mail Distribution
R. L. Gill, Jr., Manager
Nuclear Regulatory Issues
and Industry Affairs
Duke Energy Corporation
526 S. Church Street
Charlotte, NC 28201-0006
Distribution w/encl: (See page 6)
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