ML18100A538
| ML18100A538 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 08/11/1993 |
| From: | Hodges M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Miltenberger S Public Service Enterprise Group |
| Shared Package | |
| ML18100A539 | List: |
| References | |
| GL-93-04, GL-93-4, NUDOCS 9308170035 | |
| Download: ML18100A538 (5) | |
See also: IR 05000272/1993081
Text
~, ..
Docket Nos. 50-272
50-311
Mr. Steven E. Miltenberger
Vice President and Chief Nuclear Officer
Pu~lic Service Electric and Gas Company
P. 0. Box 236
Hancocks Bridge, New Jersey 08038
Dear Mr. Miltenberger:
AUG 11 1993
SUBJECT:
NRC AUGMENTED INSPECTION TEAM (AIT) REPORT NOS.
50-272/93-81 AND 50-311193-81
The enclosed report refers to a special onsite review by. an NRC Augmented Inspection Team
(AIT) from June 5 through June 28, 1993. The team reviewed the circumstances
surrounding several rod control system failures at Salem Unit 2 during May and June 1993.
The report discusses areas examined during the inspection. The scope of the inspection
included detailed fact-finding, determination of root causes, and evaluation of operational and
managerial performance. The inspection consisted of selective examination of procedures
and representative records, observations, and interviews with personnel.
The AIT determined that the predominant cause of the rod control system component failures
was the combined effect of the replacement of group step counters, which generate a higher
reverse electromotive force (EMF) than the original counters, coupled with the loss of the
coil surge suppression circuit. The loss of surge suppression resulted in the solid state
electronic components being subjected to, and damaged by, voltage spikes which were
significantly higher than their design rating. Other failures and their causes were reviewed
and are discussed in the attached report.
The team concluded that there were no clear station policy and procedures relative to the
determination of root cause of component failures. As a result, postulated causes for the
failures were not adequately tested to ensure there was a sound engineering basis to support
root cause conclusions. The team also found that station policies and procedures do not
delineate what types of problems warrant a detailed root cause investigation, nor do they
specify the relationship between root cause determination and system operability.
9308170035 930811
ADOCK 05000272
G
OFFICIAL RECORD COPY
A:SA9381.INS
. *
Mr. Steven E. Miltenberger
2
AUG 11 1993
A related observation was that the initial troubleshooting efforts lacked clear leadership and
delegation of responsibilities. This resulted in the efforts narrowly focusing on the most
recent system malfunction without adequate attention to the repetitive nature of the failures
and the need to determine and correct the root cause. The failure of PSE&G to determine
the root cause of the failures resulted in numerous aborted startup attempts. The team did
observe significant improvements in the control of troubleshooting and root cause
determination during the inspection.
The inspection also revealed that the rod control system is vulnerable to a single component
failure which could result in unintended outward control rod motion. Although the reactor
protection system is independent of the rod control system logic and, therefore, the scram
function is not compromised, there remains a concern that a previously unanticipated single-
failure mechanism may exist in the control system that can initiate or aggravate reactivity
excursions and result in fuel failure. On June 21, 1993, the NRC issued Generic Letter 93-
04, "Rod Control System Failure and Withdrawal of Rod Control Cluster Assemblies," to
notify all licensees of the problem and to request information describing their plant specific
findings and actions taken related to this issue.
The AIT found the licensed operator response to the rod control system failures and
malfunctions was excellent. The malfunctions were promptly recognized and the appropriate
actions taken in accordance with station procedures.
It is not the responsibility of an AIT to determine compliance with NRC rules and
regulations or to recommend enforcement actions. These aspects will be developed following
management review of this report.
In accordance with 10 CFR 2.790 of the Commission's *regulations, a copy of this letter and
the enclosed inspection report will be placed in the NRC Public Document Room.
We will gladly discuss any questions you have concerning this inspection.
Sincerely,
Oiiginal Signed By:
Marvin W. Hodges
Marvin W. Hodges, Director
Division of Reactor Safety
OFFICIAL RECORD COPY
A:SA9381.INS
Mr. Steven E. Miltenberger
3
AUG 11 1993
Enclosure:
Inspection Report Nos. 50-272/93-81 and 50-311/93-81
cc w/encl:
J. J. Hagan, Vice President, Nuclear Operations
C. Schaefer, External Operations - Nuclear, Delmarva Power & Light Co.
C. Vondra, General Manager - Salem Operations _
R. Hovey, General Manager - Hope Creek Operations
F. Thomson, Manager, Licensing and Regulation
R. Swanson, General Manager - QA and Nuclear Safety Review
J. Robb, Director, Joint Owner Affairs
A. Tapert, Program Administrator
R. Fryling, Jr., Esquire
M. Wetterhahn, Esquire
J. Isabella, Director, Generation Projects Department,
Atlantic Electric Company
Consumer Advocate, Office of Consumer Advocate
William Conklin, Public Safety Consultant, Lower Alloways Creek Township
K. Abraham, PAO (2)
Public Document Room (PDR)
Local Public Document Room (LPDR)
Nuclear Safety Information Center (NSIC)
NRC Resident Inspector
State of New Jersey
OFFICIAL RECORD COPY
A:SA9381.INS
-*
Mr. Steven E. Miltenberger
bee w/encl: (Via E-Mail)
J. Stone, NRR
S. Dembek, NRR
V. McCree, OEDO
M. Boyle, Acting, PDI-2, NRR
M. Wermiel, NRR
A. Thadani, NRR
J. Calvo, NRR
R." Jones, NRR
R. Cooper, DRP
D. Holody, BO
M. Hodges, DRS
C. Miller, DRS
J. Durr, DRS
W. Ruland, DRS
H. Garg, NRR
S. Barr, DRP
L. Scholl, DRP
M. Lazarowitz, DRS
DRS/EB Salp Coordinator
E. Wenzinger, DRP
J. White, DRP
T. Johnson, DRP, Salem
J. Joyner, DRSS
4
OFFICIAL RECORD COPY
A:SA9381.INS
Mr. Steven E. Miltenberger
bee w/encl: (AIT Reports Only)
Region I Docket Room (with concurrences)
The Chairman
Commissioner Rogers
Commissioner Remick
Commissioner de Planque
J. Taylor, EDO
T. Murley, NRR
W. Russell, NRR
T. Martin, RA
W. Kane, DRA
Paul Boehnert, Chairman, ACRS
Ken Raglin, Technical Training Center
DCD (OWFN Pl-37) (Dist. Code #lElO)
A. Chaffee, NRR/DORS/EAB
E. Jordan, AEOD
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OFFICIAL RECORD COPY
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