ML061800391
| ML061800391 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 06/29/2006 |
| From: | Casto C Division Reactor Projects II |
| To: | Brandi Hamilton Duke Energy Carolinas, Duke Power Co |
| Shared Package | |
| ML061800382 | List: |
| References | |
| EA-06-070, IR-06-014 | |
| Download: ML061800391 (10) | |
See also: IR 05000260/2006014
Text
June 29, 2006
Duke Power Company, LLC d/b/a
Duke Energy Carolinas, LLC (Duke)
ATTN: Mr. B. Hamilton
Vice President
Oconee Nuclear Station
7800 Rochester Highway
Seneca, SC 29672
SUBJECT:
OCONEE NUCLEAR STATION - NRC INSPECTION REPORT
05000269/2006014, 05000270/2006014, AND 05000287/2006014
Dear Mr. Hamilton:
The purpose of this letter is to provide you with the Nuclear Regulatory Commissions (NRCs)
final significance determination for a finding at Dukes Oconee Nuclear Station involving the
failure to implement timely corrective actions in resolving east penetration room blowout panel-
related deficiencies in all three Oconee Units. As documented in our letter dated March 31,
2006, this finding was assessed under the significance determination process as a preliminary
greater than Green issue (i.e., an issue of at least low to moderate safety significance), as well
as identified as an apparent violation (AV 05000269,270,287/2006012-01) of 10 CFR Part 50,
Appendix B, Criterion XVI, Corrective Action. Our letter offered you the opportunity (via
regulatory conference or in writing) to give us your assessment of the risk significance and the
associated apparent violation so that we would have a complete understanding of this issue
prior to determining the final significance.
At your request, an open regulatory conference was conducted with members of your staff on
May 17, 2006, to discuss Dukes position on this issue. The enclosures to this letter include the
list of attendees at the regulatory conference, and copies of the material presented by your staff
and the NRC at the regulatory conference. During the conference, Duke provided the results of
its risk analysis, concluding that the finding was of very low safety significance. In addition,
Duke agreed with NRCs characterization of the finding as a violation of regulatory
requirements, and advised of its plans to implement modifications to address the related
flooding concerns in all three Units by May 2007.
In addition to the uncertainties associated with not recovering secondary side heat removal,
below is a list of some of the key points raised by Duke during the regulatory conference that
were also considered [as indicated] during the NRCs post risk review:
The inclusion of welds other than girth welds was considered by Duke to be inconsistent
with the intended use of the EPRI TR-11880 pipe failure study; therefore, unlike the
NRCs phase 3 analysis, only girth welds were considered in Dukes pipe rupture
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frequency estimate. [Adjustments were made to the NRC analysis to reflect a
different weld count for the welds that could impact non-erosion/corrosion type of
failures for large break sizes (non-scalable, non-system level). Because the
proportion of scalable weld failures that result in small leaks is greater, the weld
count for these was left unchanged.]
Piping lengths used in the NRCs phase 3 analysis were different than that taken from
Dukes review of Oconee piping drawings and field walkdowns. [The Duke
measurements (adjusted up by 23 feet for Units 1 and 2 to account for auxiliary
building ventilation room piping that could flood the respective east penetration
room) were incorporated into the NRC analysis.]
Based on Dukes calculations, the automatic feedwater isolation system (AFIS) would
actuate for very large breaks; thereby, precluding flooding of the high pressure injection
(HPI) pumps. [Consideration for AFIS to isolate main feedwater from very large
breaks was incorporated into the NRC analysis.]
The scaling factor for proportional-type breaks used in the NRCs phase 3 analysis were
inappropriately based on flow rate. [The scaling factor for proportional-type breaks
was changed to more appropriately reflect a scaling factor for zero to full break
based on the pipe size.]
Duke confirmed the environmental qualification of emergency feedwater control valves
315 and 316. [The valves environmental qualification was acknowledged and
appropriately taken into account.]
Duke considered equipment less than 10 pipe diameters from main feedwater headers
to be vulnerable to jet impingement. [No credit was granted for the general
application of 10 effective pipe diameters as the zone of influence for jet
impingement, for it may not be large enough. It needs to be site specific, based
on the size of the leak and the potentially affected structures, systems, and
components.]
After considering the information developed during the inspection and the points addressed
above, the NRC has concluded that the inspection finding is appropriately characterized in the
mitigating systems cornerstone as having very low safety significance (Green). It should be
noted that the final risk determination supporting this conclusion did not take in to account
other HELB-related issues such as recovery via the standby shutdown facility with excessive
main steam safety valve cycling, HELB effects on adjacent piping systems, non-sealed
electrical penetrations and junction boxes, etc. These other HELB-related issues, along with
the blowout panel-related deficiencies, are being addressed collectively under the HELB
mitigation strategy reconstitution effort currently underway.
The subject finding was also determined to be a violation of NRC requirements, as delineated in
our March 31, 2006, letter and presented during the regulatory conference (see Enclosure 3).
However, because of its very low safety significance and because the issue was entered into
Dukes corrective action program, the NRC is treating the finding as a non-cited violation (NCV)
consistent with Section VI.A.1 of the NRC Enforcement Policy. For administrative purposes,
3
this violation will be identified as NCV 05000269,270,287/2006014-01, Failure to Promptly
Correct Long-Standing East Penetration Room Blowout Panel-Related Deficiencies That
Preclude Flood Mitigation in the Auxiliary Building. Accordingly, the associated apparent
violation AV 05000269,270,287/2006012-01 is closed.
In addition to the violation above, a related apparent violation of 10 CFR 50.73, Part (v) was
also discussed during the conference, which concerned 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). As described in our letter of March 31, 2006, this
apparent violation was not considered for escalated enforcement because its safety
significance was low and the particular regulatory process was not significantly impeded. Duke
acknowledged the violation and indicated that a licensee event report would be submitted.
As such, it has been determined that this Severity Level IV violation should be non-cited in
accordance with Section VI.A.1 of the NRCs Enforcement Policy. For administrative purposes,
this violation will be identified as NCV 05000269,270,287/2006014-02, Failure to Report East
Penetration Room Blowout Panel-Related Deficiencies Would Prevent Fulfillment of the HPI
System Safety Function. Accordingly, the associated apparent violation AV 05000269,270,287/
2006012-02 is closed.
In accordance with 10 CFR 2.390 of the NRC's "Rules of Practice," a copy of this letter
and its enclosures will be available electronically for public inspection in the NRC Public
Document Room or from the Publicly Available Records (PARS) component of NRC's
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).
Should you have any questions regarding this letter, please contact Michael E. Ernstes, Chief,
Reactor Projects Branch 1, at (404)-562-4540.
Sincerely,
//RA//
Charles Casto, Director
Division of Reactor Projects
Docket Nos.: 50-269, 50-270, 50-287, 72-04
License Nos.: DPR-38, DPR-47, DPR-55
Enclosures: 1. List of Attendees
2. Material presented by Duke
3. Material presented by NRC
cc w/encls: (see page 3)
_________________________
OFFICE
RII:EICS
RII:DRP
SIGNATURE
CFE //RA//
MEE //RA//
NAME
CEvans
MErnstes
DATE
06/29/06
06/20906
E-MAIL COPY?
YES
NO YES
NO YES
NO YES
NO YES
NO YES
NO YES
NO
Duke
4
cc w/encl:
B. G. Davenport
Compliance Manager (ONS)
Duke Power Company
Electronic Mail Distribution
Lisa Vaughn
Associate General Counsel
Duke Power Company
526 South Church Street
Mail Code EC 07H
Charlotte, NC 28202
Timika Shafeek-Horton
Assistant General Counsel
Duke Power Company
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
Henry J. Porter, Assistant Director
Div. of Radioactive Waste Mgmt.
S. C. Department of Health and
Environmental Control
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 Power Company
526 S. Church Street
Charlotte, NC 28201-0006
Charles Brinkman
Director, Washington Operations
Westinghouse Electric Company
12300 Twinbrook Parkway, Suite 330
Rockville, MD 20852
Distribution w/encl: (see page 5)
5
Letter to B. Hamilton from Charles Casto dated June 29, 2006.
SUBJECT: OCONEE NUCLEAR STATION - NRC INSPECTION REPORT 05000269/2006014,
05000270/2006014, AND 05000287/2006014
Distribution w/encl:
L. Olshan, NRR
C. Evans (Part 72 Only)
L. Slack, RII EICS
L. Trocine, OE
OEMAIL
RIDSNRRDIRS
PUBLIC
Enclosure 1
LIST OF ATTENDEES
Duke Power Company
T. Brown, Senior Civil Engineer, Oconee Nuclear Station (ONS)
G. Davenport, Regulatory Compliance Manager, ONS
R. Freudenberger, Engineering Supervisor, ONS
M. Glover, Engineering Manager, ONS
B. Hamilton, Site Vice President, ONS
L. Kanipe, Probabilistic Risk Assessment (PRA) Engineer, ONS
A. Park, Senior Civil Engineer, ONS
Nuclear Regulatory Commission
R. Bernhard, Senior Reactor Analyst, Division of Reactor Safety, Region II (RII)
R. Carroll, Senior Project Engineer, Division of Reactor Projects (DRP), RII
C. Casto, Director,DRP, RII
C. Evans, Legal Counsel/Enforcement Officer, RII
- J. Fair, Engineering & Safety Systems (ESS), Nuclear Reactor Regulation (NRR)
- P. Loeser, ESS, NRR
- G. Morris, ESS, NRR
- L. Olshan, Oconee Project Manager, NRR
D. Payne, Acting Chief, DRP Branch 1, RII
M. Shannon, Oconee Senior Resident Inspector
S. Sparks, Senior Enforcement Specialist, RII
- J. Tatum, ESS, NRR
L. Trocine, Office of Enforcement
- Participated by telephone
Enclosure 3
AGENDA
OCONEE NUCLEAR STATION
May 17, 2006
NRC REGION II OFFICE, ATLANTA, GA.
I.
OPENING REMARKS, INTRODUCTIONS AND MEETING
INTENT
Mr. C. Casto, Director, Division of Reactor Projects (DRP)
II.
NRC REGULATORY CONFERENCE POLICY
Mr. D. C. Payne, Acting Chief, Branch 1, DRP
III.
STATEMENT OF THE ISSUE WITH RISK PERSPECTIVES
Mr. D. C. Payne, Acting Chief, Branch 1, DRP
IV.
SUMMARY OF APPARENT VIOLATION
Mr. D. C. Payne, Acting Chief, Branch 1, DRP
V.
LICENSEE RISK PERSPECTIVE PRESENTATION
VI.
LICENSEE RESPONSE TO APPARENT VIOLATION
VII.
BREAK/NRC CAUCUS
Mr. C. Casto, Director, DRP
VIII.
CLOSING REMARKS
Mr. C. Casto, Director, DRP
2
Enclosure 3
Draft Apparent Violations
(1)
Considered for Escalated Enforcement:
10 CFR 50, Appendix B, Criterion XVI, Corrective Actions, requires in part
that measures be established to assure that conditions adverse to quality,
such as deficiencies, deviations, and non-conformances are promptly
identified and corrected.
Contrary to the above, a condition adverse to quality concerning east
penetration room blowout panel-related deficiencies, identified in all three
Oconee Units, was not promptly corrected. The deficiencies involved
inappropriate blowout panel modifications (identified as a violation in
2002), as well as inappropriate floor curbing and inadequate internal door
and block wall strength (all identified in DECs corrective action program in
2001). As a result of these deficiencies, the blowout panels would not be
assured of opening in the event of certain high energy line break (HELB)
scenarios, and the HELB-related flood waters would egress down into the
auxiliary building; thereby, significantly impacting the safety-related high
pressure injection pumps. Consequently, Units 1, 2, and 3 continue to be
operated outside their licensing basis with respect to HELB-related flood
mitigation in the auxiliary building.
Note: The apparent violations discussed at this Regulatory Conference are
subject to further review and subject to change prior to any resulting
enforcement action.
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Enclosure 3
Draft Apparent Violations (contd)
(2)
Not Considered for Escalated Enforcement:
10 CFR 50.73, Part (v), requires the reporting of any event or condition
that could have prevented the fulfillment of the safety function of structures
or systems that are needed to (A) shutdown the reactor and maintain it in
a safe shutdown condition (licensing basis is cold shutdown) and (D)
mitigate the consequences of an accident.
Contrary to the above, the licensee failed to report that improper
modifications to the east penetration room blowout panels would prevent
the fulfillment of the safety function of the HPI system to mitigate the
consequences of a HELB accident (i.e., to shutdown the reactor and
maintain it in a cold shutdown condition).
Note: The apparent violations discussed at this Regulatory Conference are
subject to further review and subject to change prior to any resulting
enforcement action.