ML20199B003
| ML20199B003 | |
| Person / Time | |
|---|---|
| Issue date: | 01/22/1998 |
| From: | Rossi C NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | Lochbaum D UNION OF CONCERNED SCIENTISTS |
| Shared Package | |
| ML20199B007 | List: |
| References | |
| NUDOCS 9801280155 | |
| Download: ML20199B003 (2) | |
Text
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4 UNITED STATES
- j NUCLEAR REGULATORY COMMISSION WAsHfMOToN D.C. 30ess-4001 k...../ January 22,'1998 Mr. David A. Lochbaum Union of Concerned Scientists 1616 P Street, NW, Suite 310 Washington, DC 20035-1495
Dear Mr. Lochbaum:
SUBJECT:
LOSS OF OFFSITE POWER FREQUENCY UPDATE Enclosed is a copy of a draft report
- Evaluation of Offsite Power Events at Nuclear Power Plants: 1980-1996,* INEEL/ EXT-97-00887, for your information and comments, if desired. This
' ifraft report is currently being " peer" reviewed within the NRC and by a number of extemal organizations. The objective of this study was to update the loss of offsite power (LOSP) estimates (frequency and duration) found in NUREG-1032, " Evaluation of Station Blackout Accidents at Nuclear Power Plants." This study used the same data classification scheme as in NUREG-1032, i.e., plant-centered, grid, and severe weather-related events. in addition to l estimating LOSP frequency and duration during power operation, the study also estimated the LOSF frequency and duration during shutdown.
Major findings of the study include the following:
e The i,equency of LOSP events at power is 0.04 per plant critical year for plant centered I events, 0.009 per plant critical year for severe weather events, and 0.002 per plant critical year for grid-related events, e The LOSP frequency from grid-related events is a very small contributor to LOSP events, o Plant-centered LOSP events at power do not show plant-to-plant variability while plant-centered events during shutdown do show significant statistical plant-to-plant variability, e Severe weather LOSP events showed site-to-site variability for both power and shutdown modes.
- . LOSP events and durations are ponerally better than those calculated in NUREG-1032
!n support of the station blackout rulemaking.
Should you desire to provide any comments, we would appreciate receiving them within 45 days from receipt of this latter. -
98-b As you may know, the Office for Analysis and Evaluation of Operational Data studies do not represent an official U.S. Nuclear Regulatory Commission position or the position of the , l
' responsible NRC program office. Our reports are one input to an ongoing review and [
evaluation process. J
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l-o o e Mr. David A. Lochbaum '
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A copy of this draft report and letter are being placed in the Public Document Room at 2120 L Street NW, Washington, DC 20555.
If you have any questions related to this report, please feel free to contact Dr. Dale Rasmuson (301-415 7571) (e-mail: dmr@nrc. gov) of my staff.
Sincerely, Original signed by:
Charles E. Rossi, Director Safety Programs Division Office for Analysis and Evaluation of Operational Data
Enclosure:
As stated Distribution w/ encl:
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Public -
Distribution w/o encl.:
AThadani, DEDE TTMartin DHickman PBaranowsky SMays DRasmuson JRosenthal JMitchell, OEDO SPD R/F RRAB R/F
. H:\SPD\ROSSl\LOCHBAUM.REV To receeve e copy o' tNo document. indicnes in the box: "C" = Copy wo/attachtencle "E" = Copy wlattacNoncle "N" = No copy OFFICE SPD c NAME CERos(A DATE 01/,;t2/98
- OFFICIAL RECORD COPY j