ML100150327
| ML100150327 | |
| Person / Time | |
|---|---|
| Site: | Byron  |
| Issue date: | 01/14/2010 |
| From: | Stephanie West Division of Nuclear Materials Safety III |
| To: | Pardee C Exelon Generation Co, Exelon Nuclear |
| References | |
| EA-09-247 | |
| Download: ML100150327 (5) | |
See also: IR 05000455/2009003
Text
UNITED STATES
NUCLEAR REGULATORY COMMISSION
REGION III
2443 WARRENVILLE ROAD, SUITE 210
LISLE, IL 60532-4352
January 14, 2010
Mr. Charles G. Pardee
Senior Vice President, Exelon Generation Company, LLC
President and Chief Nuclear Officer (CNO), Exelon Nuclear
4300 Winfield Road
Warrenville IL 60555
SUBJECT:
RESPONSE TO DISAGREEMENT REGARDING CROSS-CUTTING ASPECT
ASSOCIATED WITH NON-CITED VIOLATION, BYRON STATION, UNIT 2,
INSPECTION REPORT 05000455/2009003
Dear Mr. Pardee:
On December 18, 2009, Mr. Daniel J. Enright, Exelon Generation Company, LLC (Exelon),
Byron Station, Unit 2, provided a response to an NRC Inspection Report issued on August 7,
2009, concerning activities conducted at your facility. Specifically, the Exelon letter disagreed
with the cross-cutting aspect associated with a non-cited violation (NCV) contained in the
inspection report, namely NCV 05000455/2009003-01, regarding the Failure to comply with
Technical Specification (TS) 3.4.13.B reactor coolant system (RCS) pressure boundary
leakage." In our inspection report, we determined that the primary cause for this finding was
related to the cross-cutting area of Human Performance and its associated component for
Decision Making (H.1(b)), because licensee management personnel concluded that the leak did
not represent reactor coolant pressure boundary leakage due to the closure of an isolation
valve. The Exelon letter indicated that the cross-cutting aspect for the NCV was more closely
associated with a Human Performance component of Resources (H.2(c)).
The Exelon letter indicated that the decision on leak classification was based on available
resources including the site procedures, processes, and training with respect to isolating the line
to eliminate the pressure boundary leakage condition. Exelons position is that the plant was
placed in a safe and conservative configuration as a result of actions to verify that a valve
(2PS9350B) upstream from the leak was closed. Although the valve was closed, valve seat
leakage allowed reactor coolant to continue leaking, albeit at a small rate, through the piping
fault. The licensee indicated that the violation was attributed to the TS not being clear with
regard to the definition of pressure boundary leakage associated with a non-isolable reactor
coolant system leakage through a fault. Exelon contends that the TS was applied as
understood at the time by isolating the fault condition without making an assumption in its
decision making. Therefore, Exelon disagreed with the characterization of the cross-cutting
aspect being classified as Human Performance with an associated component of Decision
Making (H.1(b)). Furthermore, Exelon contends that a more accurate classification and
characterization of the cause for the violation would be the cross-cutting area of Human
Performance with an associated component of Resources (H.2(c)).
C. Pardee
-2-
The NRC staff, independent of the original inspectors and approvers, reviewed Exelons basis
for disagreeing with the characterization of the cross-cutting aspect associated with the
violation. From the description of the violation in the associated inspection report, it appears
that:
1.
The licensee identified pressure boundary leakage on June 24, 2009, as a pinhole
leak (one drop every 5 minutes) on a welded connection inside the Unit 2
containment. The welded connection is on line 2PS01BB and the line is 3/8 inch in
diameter. This line is a pressurizer liquid sample line and is a non-safety related
non-American Society of Mechanical Engineer code, Class D pipe.
2.
The licensee verified that valve 2PS9350B upstream of the leak was closed and that
both containment isolation valves downstream of the leak were closed.
3.
Despite the fact that the upstream valve was closed, the leak continued.
4.
The Shift Manager made a decision that the leak did not constitute reactor pressure
boundary leakage.
5.
Based on that decision, the licensee failed to take the required TS action (be in
Mode 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />), resulting in the violation.
Based on this description, it appears that a non-conservative decision was made that had a
direct bearing on the violation. In Appendix A, Components within the Cross-Cutting Areas, to
NRC Inspection Manual Chapter 0305, Operating Reactor Assessment Process, the description
of H.1(b) is as follows:
The licensee uses conservative assumptions in decision making and adopts a
requirement to demonstrate that the proposed action is safe in order to proceed rather
than a requirement to demonstrate that it is unsafe in order to disapprove the action.
The licensee conducts effectiveness reviews of safety-significant decisions to verify the
validity of the underlying assumptions, identify possible unintended consequences, and
determine how to improve future decisions.
Regardless of the perceived adequacy or inadequacy of licensee available resources, including
site procedures, processes, and training with respect to isolating the line to eliminate the
pressure boundary leakage, and in the face of uncertainty (continued leakage), site
management had the option of making a more conservative decision, including affecting repairs
within the TS action time to eliminate the pressure boundary leakage or complying with the
action requirement to be in Mode 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
Therefore, after careful consideration of the information you provided, we have concluded that
the characterization of the cross-cutting aspect associated with the violation is as stated in the
inspection report. We consider this matter closed.
C. Pardee
-3-
In accordance with 10 CFR 2.390 of the NRC's "Rules of Practice," a copy of this letter and your
December 18, 2009, response will be available electronically for public inspection in the NRC
Public Document Room or from the NRC's document system (ADAMS), accessible from the
NRC Web site at http://www.nrc.gov/reading-rm/adams.html.
Sincerely,
/RA/
Steven West, Director
Division of Reactor Projects
Docket No. 50-455
License No. NPF-66
cc: Distribution via ListServ
C. Pardee
-3-
In accordance with 10 CFR 2.390 of the NRC's "Rules of Practice," a copy of this letter and your
December 18, 2009, response will be available electronically for public inspection in the NRC
Public Document Room or from the NRC's document system (ADAMS), accessible from the
NRC Web site at http://www.nrc.gov/reading-rm/adams.html.
Sincerely,
/RA/
Steven West, Director
Division of Reactor Projects
Docket No. 50-455
License No. NPF-66
cc: Distribution via ListServ
DOCUMENT NAME: G:\\Byron\\Byron CCA Disagreement.doc
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OFFICE
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NAME
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SWest
DATE
1/13/10
1/14/10
OFFICIAL RECORD COPY
Letter to C. Pardee from S. West dated January 14, 2010.
SUBJECT:
RESPONSE TO DISAGREEMENT REGARDING CROSS-CUTTING ASPECT
ASSOCIATED WITH NON-CITED VIOLATION, BYRON STATION, UNIT 2,
INSPECTION REPORT 05000455/2009003
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