ML11255A192
| ML11255A192 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 09/07/2011 |
| From: | O'Grady B Nebraska Public Power District (NPPD) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| EA-11-176, NLS2011091 IR-11-006 | |
| Download: ML11255A192 (6) | |
See also: IR 05000298/2011006
Text
N Nebraska Public Power District Always there when you need us NLS2011091
2.201 September
7, 2011 U.S. Nuclear Regulatory
Commission
Attention:
Document Control Desk Washington, D.C. 20555-0001
Subject: Reply to Notice of Violation 05000298/2011006-05;
EA-2011-176
Cooper Nuclear Station, Docket No. 50-298, DPR-46 References:
1. Letter to Brian J. O'Grady (Nebraska
Public Power District)
from Dr. Dale A.Powers (U.S. Nuclear Regulatory
Commission)
dated August 8, 2011,"Cooper Nuclear Station -NRC Problem Identification
and Resolution
Inspection
Report 05000298/2011006
and Notice of Violation" 2. Letter to Brian J. O'Grady (Nebraska
Public Power District)
from Thomas R.Farnholtz (U.S. Nuclear Regulatory
Commission)
dated December 3, 2010,"Cooper Nuclear Station -NRC Component
Design Bases Inspection
Report 05000298/2010007" Dear Sir or Madam: The purpose of this correspondence
is to provide Nebraska Public Power District's (NPPD) reply to a Notice of Violation
in accordance
with 10 CFR 2.201. By letter dated August 8, 2011 (Reference
1), the Nuclear Regulatory
Commission
cited NPPD for being in violation
of 10 CFR Part 50, Appendix B, Criterion
III, Design Control.The violation
is concerned
with Cooper Nuclear Station failing to assure that applicable
regulatory
requirements
and the design basis were correctly
translated
into specifications, drawings, procedures
and instructions
within a reasonable
amount of time after a previous noncited violation (Reference
2) documented
the same issue.NPPD accepts the violation
and recognizes
the importance
of its responsibilities
with respect to design basis control. As discussed
in the attachment
to this letter, NPPD has taken prompt action to return to compliance
with 10 CFR Part 50, Appendix B, Criterion
III, and to prevent recurrence
of this violation.
COOPER NUCLEAR STATION \P.O. Box 98 / Brownville, NE 68321-0098
Telephone:
(402) 825-3811 / Fax: (402) 825-5211 www.nppd.com
NLS2011091
Page 2 of 2 If you have any questions
concerning
this matter, please contact David Van Der Kamp, Licensing Manager, at (402) 825-2904.Sinc rely, Brian J.O'Gra y Vice President
-Nuclear and Chief Nuclear Officer/bk Attachment
cc: Regional Administrator
w/ attachment
USNRC -Region IV Cooper Project Manager w/ attachment
USNRC -NRR Project Directorate
IV-1 Senior Resident Inspector
w/ attachment
USNRC -CNS NPG Distribution
w/ attachment
CNS Records w/ attachment
NLS2011091
Attachment
Page 1 of3 REPLY TO NOTICE OF VIOLATION 05000298/2011006-05;
EA-2011-176
COOPER NUCLEAR STATION, DOCKET NO. 50-298, DPR-46 During Nuclear Regulatory
Commission (NRC) inspection
activities
conducted
June 6 through June 24, 2011, a violation
of NRC requirements
was identified.
The violation
and Nebraska Public Power District's (NPPD) reply are set forth below: Restatement
of the Violation"Title 10 CFR 50, Appendix B, Criterion
III, "Design Control, "requires, in part, measures shall be established
to assure that applicable
regulatory
requirements
and the design basis, as defined in 10 CFR 50.2 and as specified
in the license application,.for
those components
to which this appendix applies, are correctly
translated
into specifications, drawings, procedures, and instructions.
Contrary to the above, since December 3, 2010, the licensee failed to assure that applicable
regulatory
requirements
and the design basis were correctly
translated
into specifications, drawings, procedures, and instructions.
Specificallv, the licensee failed to correctly
translate regulatory
and design basis requirements, associated
with tornado and high wind generated missiles, into design information
necessary
to protect the emergency
diesel generator
fuel oil day tank vent line components.
This violation
is associated
with a Green Significance
Determination
Process finding." Background
During the 2010 Component
Design Bases (CDB) Inspection, conducted
July 21, 2010, to October 20, 2010, at Cooper Nuclear Station (CNS), NRC personnel
questioned
whether analysis existed for a postulated
tornado-induced
missile strike on the number one emergency
diesel generator's (EDG) fuel oil day tank vent line. The EDG fuel oil day tank vent lines at CNS are made of six-inch diameter, schedule 40 thick steel pipe. The vent lines run from each EDG's fuel oil day tank to outside of the EDG rooms, and extend upward along the exterior wall of the turbine building and terminate
at a vent cap. CNS determined
the current configuration
of the EDG fuel oil day tank lines acceptable
based on an original Bums and Roe civil design specification
which documented
the worst case for the tornado-induced
missile scenario;
i.e., impact of a wooden utility pole traveling
at 200 miles per hour. CNS did not have a formal design basis calculation
on record to support this conclusion
and initiated
a corrective
action to develop one.In the CDB Inspection
Report dated December 3, 2010 (Reference
2), the NRC documented
seven examples as a green noncited violation (NCV) of 10 CFR Part 50, Appendix B, Criterion III, "Design Control," for failure to establish
measures to ensure that applicable
regulatory
requirements
and the design bases were correctly
translated
into specifications, drawings, procedures, and instructions.
Reference
2 specified
that this finding applied to the tornado and high wind impact on the EDG fuel oil storage facilities.
NLS2011091
Attachment
Page 2 of 3 On December 14, 2010, CNS design engineering
completed
a calculation, and associated
engineering
evaluation, to evaluate a postulated
tornado-induced
missile impact on the EDG fuel oil day tank vent lines. The evaluation
concluded
that the existing EDG day tank vent lines were adequate after a postulated
tornado strike and able to provide venting.From June 6, 2011, to June 24, 2011, the NRC conducted
a Problem Identification
and Resolution
inspection
at CNS. During this inspection, the NRC noted that the design basis calculation
performed
in December 2010, and subsequent
revisions, contained
non-conservative
assumptions
related to net positive suction head and head loss, that could affect the outcome of the calculation.
CNS reviewed the calculation
and determined
additional
clarifying
engineering
analysis would be required to resolve the NRC's concern.In Reference
1 the NRC discussed
its review of the December 2010 calculation
and corrective
actions taken in response to the CDB Inspection
NCV, and concluded
that CNS had failed to restore compliance
within a reasonable
time after the NCV was identified
on December 3, 2010.Specifically, CNS failed to correctly
translate
regulatory
and design basis requirements, associated
with tornado and high wind generated
missiles, into design information
necessary
to protect the EDG fuel oil day tank vent line components.
Reason for Violation NPPD accepts the cited violation.
CNS performed
an evaluation
utilizing
root cause analysis.
The root cause team reviewed the December 2010 calculation, associated
engineering
evaluation, and subsequent
revisions.
The team identified
that the calculation
was inadequate.
When the December 2010 calculation
was being prepared, a decision was made by CNS engineering
supervision
to pursue the worst case approach;
i.e., assuming the EDG fuel oil day tank steel vent line would be flattened
and pinched off. The engineer assigned to prepare the calculation
was provided with this presumed result and was not tasked with determining
the result of the impact based upon the original design basis scenario.
Rather, the evaluation
attempted
to demonstrate
no adverse effect to EDG operation.
The root cause for the condition, cited in Reference
1, is underestimation
of the scope and task to address an NCV. In summary, CNS failed to resolve a design basis issue in a timely manner because an initial decision had been made by CNS engineering
supervision
to develop an operability
type evaluation.
This decision resulted in a calculation
that focused on addressing
the operability
of the vent pipe after impact, rather than generation
of the missing design basis analysis of the impact.Corrective
Steps Taken and Results Achieved CNS has performed
a new calculation
to evaluate the design basis tornado-induced
missile impact on the EDG fuel oil day tank vent lines. This calculation
is approved and implemented, and supersedes
the December 2010 calculation
and associated
engineering
evaluation.
NLS2011091
Attaclunent
Page 3 of 3 Corrective
Steps That Will Be Taken to Avoid Further Violations
The action described
above will prevent further violations
related to translating
regulatory
and design basis requirements
for tornado and high wind generated
missiles into design information
necessary
to protect the EDG fuel oil day tank vent line components.
Additional
Corrective
Actions CNS will deliver a case study of the decision making aspects of this issue to design engineering
supervisors.
CNS will also review calculation
assignments
in the civil engineering
department
made in the past 18 months to determine
if any were directed towards establishing
operability
rather than addressing
design basis.Date When Full Compliance
Will Be Achieved NPPD has restored compliance
with 10 CFR Part 50, Appendix B, Criterion
III.References
1. Letter to Brian J. O'Grady (Nebraska
Public Power District)
from Dr. Dale A. Powers (U.S.Nuclear Regulatory
Commission)
dated August 8, 2011, "Cooper Nuclear Station -NRC Problem Identification
and Resolution
Inspection
Report 05000298/2011006
and Notice of Violation" 2. Letter to Brian J. O'Grady (Nebraska
Public Power District)
from Thomas R. Farnholtz (U.S.Nuclear Regulatory
Commission)
dated December 3, 2010, "Cooper Nuclear Station -NRC Component
Design Bases Inspection
Report 05000298/2010007"
ATTACHMENT
3 LIST OF REGULATORY
COMMITMENTSC
4 ATTACHMENT3
LIST OF REGULATORY
COMMITMENTSN4
Correspondence
Number: NLS2011091
The following
table identifies
those actions committed
to by Nebraska Public Power District (NPPD) in this document.
Any other actions discussed
in the submittal
represent
intended or planned actions by NPPD. They are described
for information
only and are not regulatory
commitments.
Please notify the Licensing
Manager at Cooper Nuclear Station of any questions
regarding
this document or any associated
regulatory
commitments.
COMMITMENT
NUMBER OR OUTAGE None-4- 4 PROCEDURE
0.42 REVISION 27 PAGE 18 OF 25