ML20212N600
| ML20212N600 | |
| Person / Time | |
|---|---|
| Issue date: | 08/15/1986 |
| From: | Heltemes C NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | Harold Denton, Ross D, Taylor J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE), Office of Nuclear Reactor Regulation, NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES) |
| Shared Package | |
| ML20212N602 | List: |
| References | |
| NUDOCS 8608280301 | |
| Download: ML20212N600 (3) | |
Text
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UNITED STATES g
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August 15, 1986 AE0D/P602
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i MEMORANDUM FOR: Harold R. Denton, Director, NRR James M. Taylor, Director, IE Denwood F. Ross, Jr., Acting Director, RES Ronald M. Scroggins, Director, RM Thomas E. Murley, Regional Administrator, Region I J. Nelson Grace, Regional Administrator, Region II James G. Keppler, Regional Administrator. Region III Robert D. Martin, Regional Administrator, Region IV i
John B. Martin, Regional Administrator, Region V FROM:
C. J. Heltemes, Jr., Director i
Office for Analysis and Evaluation of Operational Data
SUBJECT:
TRENDS AND PATTERNS REPORT OF UNFLANNED REACTOR TRIPS AT U.S. LIGHT WATER REACTORS,IN 1985 i
i l
Enclosed is a final report of a trends and patterns analysis of unplanned reactor trips (i.e~., reactor scrams) that occurred in 1985 at U.S. nuclear J
power plants.
In this report we define a reactor trip (i.e., scram) as eny actuation of the Reactor Protection System (RPS) whether automatic or manual 1
which results in control rod motion. Plants were included in the trip l
statistics contained in this report if they: (1) held a full power operating license and (2) accumulated critical hours for some portion of the calendar year 1985.
s Based upon the evaluations and analyses described in this report, we have arrived at the following general observations with regard to reactor trips:
(a) in terms of the overall performance of the industry we observed only a slight change in the total trip rate from 1984 to 1985; i.e., 5.9 and 6.0 i
trips per reactor year, respectively; (b) hardware failure in Power Conversion Systems (Feedwater, Condensate, Main Steam Turbine, Main Generator) dominated i
in 1985, and a reduction in such hardware failures would significantly reduce l
the number of reactor trips; (c) at power levels above 15 percent, approximately
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10 percent of all reactor trips were caused by unlicensed personnel; and (d) i there are a number of post trip recovery complications due to equhment failures and personnel errors unrelated to the original trip cause that have the potential for having significant safety implications.
In addition to these general observations, the report contains a number of i
specific conclusions based upon the analysis of the 552 reactor trips which I
were identified in 1985.
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, Multiple Addressees We are placing a copy of this final report in the Public Document Room.
If you have any questions regarding.this matter, please feel free to contact me or Lawrence Bell of my staff. Mr. Bell can be reached on 492-4492.
Onube saw by C. J. Hemaman, Jr.
C. J. Heltemes, Jr., Director Office for Analysis and Evaluation of Operational Data
Enclosure:
As Stated cc w/ enclosure:
See Attached Distribution:
PTB SF PTB CF AE0D SF AE0D CF LBell RDennig FHebdon CHeltemes PDR OFC :PTB
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DATE:8/*f/86
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0FFICIAL RECORD COPY
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Cistribution:
V. Stello, EDO J. Roe, DEDO.
T. Rehm, A0/ED0 J. Sniezek, DEDR0GR W. Brach, DEDROGR H. Thompson, NRR R. Bernero, NRR T. Speis, NRR W. Russell, NRR G. Holahan, NRR G. Arlotto, RES F. Gillespie, RES E. Jordan, IE S. Schwartz, IE J. Partlow, IE J. Shea IP H. Faulkner, IP D. Humenansky, OCM K. Raglin, RTC K. Murphy, RI E. Schweibinz, RIII SRI, Byron 1, RIII SRI, Callaway 1, RIII SRI, Diablo Canyon 2 RV SRI, Waterford 3, RIV SRI, Palo Verde 1, RV SRI, Grand Gulf 1, RII SRI, Catawba, RII SRI, Wolf Creek, RIV i
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