ML15244A800
| ML15244A800 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 02/22/1993 |
| From: | Merschoff E NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Jenkins G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| NUDOCS 9303090501 | |
| Download: ML15244A800 (3) | |
Text
FEB 22 1993 MEMORANDUM FOR:
George R. Jenkins, Director, EICS FROM:
Ellis W. Merschoff, Director, DRP
SUBJECT:
SIMILAR (REPEAT)
SL-IV VIOLATION; NO ESCALATED ENFORCEMENT PROPOSED FACILITY:
OCONEE 1, 2, 3 INSP: RPT. NO.:
050-269, 270, 287/93-03 The inspection referenced above identified a similar violation, as defined in the NRC Enforcement Policy.
I have evaluated the Branch Chief's recommendation and concluded that escalated enforcement is not warranted, based on the factors checked below:
Pervasiveness of the problem:
The problem, failure to follow procedures to ensure the proper movement of all fuel assemblies during a refueling outage, is not considered to be pervasive.
The frequency of such events is about once per year for the 3-Unit Oconee site over the past four years.
Considering the number of fuel movements per outage and the number of outages per year this equates to an error rate of the order of one per each thousand fuel assembly movements.
Similarities in the violation - The events in August 1991 and December 1992 are essentially identical.
Adequacy of the past corrective actions, including implementation.
Previous corrective actions have included additional spent fuel bridge indexing devices and procedural enhancements.
These actions by themselves apparently have not been adequate to overcome the most likely root cause of occasional inattention to detail in a task which is repetitive and demanding of precision and verification.
Extent of Prior Notice given -
other than the NRC violation issued no licensee audits or QC findings have focussed on similar prior events.
Significance of the violations.
These events did not have high safety significance.
These improper positioning of fuel assemblies was discouraged by the licensees refueling team during fuel movement activities in one instance and by a required video scan verification of the fully loaded core in the second instance.
It is also likely that the consequences of such misloading would have been clearly evident during startup zero power 9303090501 930222 PDR ADOCK 05000269 0
FEB 2 2 1993 George R. Jenkins 2
physics testing, whereupon remedial actions would have been taken.
Whether past violations were included in an escalated enforcement action - A violation over two years ago, in October 1990, was one of three examples of failure to follow procedures that, collectively were determined to be a Level IV Violation. A violation in August 1991 was considered to be a repeat of the October 1990 violation and was determined to be a Level IV violation.
Adequacy of the corrective actions after the repeat violation was identified.
The previous corrective actions have not been sufficient to reduce this type of error below a frequency of about once per year for the three unit site.
An enforcement letter and Notice of Violation has been prepared for my signature in accordance with Regional Office Instruction No.
- 0903, "Action Required for Similar (Repeat)
Severity Level IV or V violations."
E. W. Merschoff I
RI e
t 02////93 2/
93
February 11, 1993 Enclosure ELECTRICAL ENGINEERING BRANCH REVIEW COMMENTS ON PRELIMINARY ASP EVALUATION OF THE OCONEE 2 LOOP EVENT OF OCTOBER 19, 1992
- 1. In the first paragraph under "Summary," the second sentence states that an operator error at Keowee caused the loss of auxiliary power to both hydro units. While this is generally true, two additional random failures occurred which prevented the automatic transfer of the auxiliary power buses to the alternate source greatly compounding the operator's misjudgment.
- 2. In the fourth paragraph under "Event Description," it is stated that Oconee 1 and 3 would not have had a source of offsite power available if they had tripped. This is true from an "automatic" sense. As a last resort power was available (manually) within a few minutes from the beginning of this event from the 100 kV Central Switchyard and from the Lee gas turbine approximately 60 minutes into the event. This same comment applies to the last sentence in the ninth paragraph. Also the sentence in the fourth paragraph states PCBs-17 and 26 were open. This should probably be PCBs-17 and 30.
- 3. The eighth.paragraph under "Additional Event-Related Information" should be rewritten along the lines of first paragraph under "Event Description."
- 4. In the first paragraph under "ASP Modeling Assumptions and Approach," the term "failed emergency power" is used. Does this mean both Keowee units were assumed to be failed? If so, it should be noted that Keowee Unit 2 was only unavailable for about 31 seconds while Keowee Unit 1 was also unavailable. Also again as a last resort, power through CT5 was available throughout the event with manual action required.
- 5. In the third paragraph under "ASP Modeling Assumptions and Approach," the last sentence may also need to address power being available manually via CT5.
- 6. In the last sentence of the fifth'paragraph under "ASP Assumptions and.
Approach," the failure of Keowee to be non-recoverable may also need to be conditioned by the other sources of power such as CT5 or the Keowee units themselves not being available.