ML17187A487
| ML17187A487 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 06/14/1996 |
| From: | Miller H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Jamila Perry COMMONWEALTH EDISON CO. |
| Shared Package | |
| ML17187A488 | List: |
| References | |
| EA-96-207, NUDOCS 9606250244 | |
| Download: ML17187A487 (4) | |
See also: IR 05000249/1996008
Text
Mr. J. S. Perry
Site Vice President
Dresden Station
Convnonwealth Edison Company
6500 North Dresden Road
Morris, IL 60450
June 14, 1996
SUBJECT:
NRC REGION III AUGMENTED INSPECTION TEAM REVIEW OF THE
MAY 15, 1996, DRESDEN UNIT 3 FAILURE OF THE 3B FEEDWATER
REGULATING VALVE.
INSPECTION REPORT NO. 50-249/96008.
Dear Mr. Perry:
The enclosed report refers to a special review by an NRC Augmented Inspection
Team {AIT) from May 16 through 23, 1996, relative to the May 15, 1996, failure
of a feedwater regulating valve {FRV) and subsequent reactor trip and
emergency core coolant systems {ECCS) actuation at the Dresden Nuclear
Station, Unit 3.
The AIT was composed of Messrs. P. Hiland {Team Leader),
J. Hopkins, P. Louden, J. Guzman, D. Butler, and D. Roth of this office; and
J. Stang of the Office of Nuclear Reactor Regulation {NRR).
The report also
refers to the followup activities of your staff and to the discussion of our
findings with you and others of your staff during a public meeting at the
conclusion of the inspection on May 23, 1996.
The enclosed copy of our AIT report identifies areas examined during the
inspection. Within these areas, the inspection consisted of a selective
examination of procedures and representative records, observations, and
interviews with personnel.
The AIT was formed to assess information regarding the Hay 15 loss of
feedwater event. Specifically, the AIT examined the plant equipment and
personnel response to the event and root causes for equipment failures.
During the event, no operational safety limits were approached or exceeded.
Response to the event by operations, engineering, and plant support was good.
The AIT determined that the event's immediate safety consequence was minimal,
since the safety systems operated as designed to safely mitigate the
consequences of the total loss of feedwater transient.
However, the AIT also
concluded that the engineering and maintenance backlogs contributed to the
transient. Specifically, at the time of the transient, the plant was
operating with only a single feedwater regulating valve in service. The
redundant feedwater regulating valve was isolated due to a steam leak that was
known to be a problem since September 1995.
When the in-service valve failed,
the total loss of feedwater resulted in a reactor trip and emergency core
cooling system {ECCS) automatic injection. If the redundant valve had been in
service, ECCS injection would not be expected.
In addition, the failure
9606250244 960614
ADOCK 05000249
G
- J. S. Perry
- 2 -
mechanism for two primary containment isolation valves, which opened
unexpectedly, could have been corrected in 1994 and 1995 had a thorough review
of earlier problems been performed.
The decision to isolate the redundant FRY and operate Unit 3 for a prolonged
period with only a single FRY in service was primarily based on the existing
personnel safety hazard associated with the steam leak from the FRY in the
redundant train.
Past feedwater system performance and the risk contribution
described in the Dresden Station Individual Plant Evaluation were not
adequately considered.
In addition, the decision to inspect the 38 FRY valve
stem at a frequency of every two refueling outages had no technical or risk-
informed basis.
We conclude these narrowly focussed decisions are
inconsistent with the conservative operati~nal philosophy that has been
demonstrated over the past several months at the Dresden Station.
We recognize your efforts ov~r the past year to reduce the engineering and
maintenance backlogs.
However, the loss of feedwater transient emphasizes the
need for continued senior management attention to assure the station minimizes
the backlogs and their potential impact on the operation of the plant.
It is not the responsibility of an All to determine compliance with NRC rules
and regulations or to reconunend enforcement actions. These aspects will be
reviewed in a subsequent inspection ..
In accordance with 10 CFR 2.790 of the Conunission's regulations, a copy of
this letter and the enclosed inspection report will be placed iry the NRC
Public Document Room.
Docket No. 50-249
Enclosure:
Inspection Report
No. 50-249/96008
Sincerely,
Original Signed by A. B. Beach
Hubert J. Miller
Regional Administrator
J. S. Perry
-3-
cc w/encl:
J. C. Brons, Vice President,
Nuclear Support
H. W. Keiser, Chief Nuclear
Operating Officer
T. Nauman, Station Manager Unit 1
M. Heffley, Station Manager Units 2 and 3
F. Spangenberg, Regulatory Assurance
Manager
D. Farrar, Nuclear Regulatory
Services Manager
Richard Hubbard
Nathan Schloss, Economist
Office of the Attorney General
State Liaison Officer
Chairman, Illinois Commerce Commission
Document Control Desk-Licensing
Distribution:
Docket File w/encl
PUBLIC IE-01 w/encl
OC/LFDCB w/encl
Project Manager, NRR w/encl
DRP w/encl
SRI LaSalle, Dresden,
Quad Cities w/encl
C. D. Pederson, w/encl
RAC! (E-Mail)
Commissioner Rogers
D. C. Trimble, Jr., OCM
J. M. Taylor, EDO
W. T. Russell, NRR
J. A. Zwolinski, NRR
A. C. Thadani, NRR
A. E. Chaffee, NRR
E. L. Jordan, AEOD
A. F. Gibson, RII
S.
R~ Stein, SRS
J. R. Goldberg, OGC
Riii PRR w/encl
IPAS (E-Mail) w/encl
RMB/FEES w/o encl
A. B. Beach, w/encl
The Chairman
Commissioner Dicus
D. A. Ward, ACRS
J. L. Milhoan, DEDR
J. W. Roe, NRR
J. N. Hannon, NRR
C. E. Rossi, NRR
R.
P~ Zimmerman, NRR
M. W. Hodges, RI
T. P. Gwynn, RIV
J.
Lieberman, OE
DOCUMENT NAME:
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DATE
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OF ICIAL RECORD COPY
Distribution:
Docket* File w/encl
PUBLIC IE-01 w/encl
OC/LFDCB w/encl
SRI LaSalle, Dresden,
Quad Cities w/encl
C. D. Pederson, w/encl
RACl (E-Mail)
Commissioner Rogers
D. C. Trimble, Jr., OCM
J. M. Taylor, EDO
W. T. Russell, NRR
J. A. Zwolinski, NRR
A. C. Thadani, NRR
A. E. Chaffee, NRR
E. L. Jordan, AEOD
A. F. Gibson, RII
S. R. Stein, SRS
J. R. Goldberg, OGC
Project Manager, NRR w/encl
DRP w/encl
RII I PRR w/encl
!PAS (E-Mail) w/encl
RMB/FEES w/o encl
A. B. Beach, w/encl
The Chairman
Commissioner Dicus
D. A. Ward, ACRS
J. L. Milhoan, DEDR
J. W. Roe, NRR
J. N. Hannon, NRR
C. E. Rossi, NRR
R. P. Z i mmerma*n , NAA'
M. W. Hodges, RI
T. P. Gwynn, RIV
J.
Lieberman, OE
DOCUMENT NAME:
R:\\INSPRPTS\\POWERS\\DRES\\DRE96008.DRP
To receive a copy of this document, indicate In the boa *c* * Copy without attach/encl "E" * Copy with attach/encl
"N" *
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DATE
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OFFICIAL RECORD COPY