ML19305C126
| ML19305C126 | |
| Person / Time | |
|---|---|
| Site: | Dresden, LaSalle  |
| Issue date: | 03/10/1980 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Reed C COMMONWEALTH EDISON CO. |
| References | |
| NUDOCS 8003260029 | |
| Download: ML19305C126 (1) | |
Text
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'o UNITED STATES 8
NUCLEAR REGULATORY COMMISSION
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799 ROOSEVELT ROAD oLEN ELLYN. ILLINOIS 60137
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5Ait io q Docket Nos. 50-10, 50-237, 50-249, 50-373, 50-374 Commonwealth Edison Company ATTN:
Mr. Cordell Reed Vice President Post Office Box 767 Chicago, IL 60690 Gentlemen:
This Information Notice is provided as a notification of a possibly significant matter.
It is expected that recipients will review the information for possible applicability to their facilities. No specific action or response is requested at this time.
If further NRC evaluations so indicate, an IE Circular or Bulletin will be issued to recommend or request specific licensee actions.
If you have questions regarding this matter, please contact the Director of the appropriate NRC Regional Office.
Sincerely, O'
n ames G. Keppler Director
Enclosure:
IE Information Notice No. 80-04 cc w/ enc 1:
Mr. D. L. Peoples, Director Central Files of Nuclear Licensing Director, NRR/DPM Mr. B. B. Stephenson, Director, NRR/ DOR Station Superintendent PDR Mr. N. Kalivianakis, Local PDR Station Superintendent NSIC Mr. L. J. Burke M
Project Superintendent Mr. Dean Hansell, Office of Mr. T. E. Quake, Quality Assistant Attorney General Assurance Supervisor Myron M. Cherry, Chicago Mr. R. H. Holyoak, Station Superintendent F5003ccoo p
UNITED STATES SSINS No.:
6870 NUCLEAR REGULATORY COMMISSION Accession No.:
OFFICE OF INSPECTION AND ENFORCEMENT 7912190655 WASHINGTON, D.C.
20555 y-q ep February 4, 1980 ng g
iso IE Information Notice No. 80-04 BWR FUEL EXPOSURE IN EXCESS OF LIMITS On November 1, 1979, and December 17, 1979, respectively, the licensees of the Quad Cities Unit No. 1 and Monticello Nuclear Power Plants informed the Nuclear Regulatory Commission that the actual peak average planar exposure of some fuel assemblies in the core was beyond the maximum average planar exposure value of the Maximum Average Planar Linear Heat Generation Rate (MAPLHGR) Limits specified in the plant Technical Specifications.
In the case of Quad Cities, the licensee was aware that some fuel assemblies would approach and exceed the exposures for which MAPLHGR limits had been analyzed.
In the interim, the station prosess computer was used to calculate higher exposure MAPLHGR limits via an extrapolation routine, while awaiting determination of the additional high exposure MAPLHGR limits using standard licensing analysis methods. When the actual limits were made available for comparison with the extrapolated values, it was determined that the process computer had extrapolated values non-conservatively.
Although the new MAPLHGR limits extensions were immediately entered into the computer, the new limits had not yet been submitted for review and approval by the NRC.
With regard to Monticello, 1 licensee became aware that the 30,000 MWD /T maximum exposure specified in the plant Technical Specifications were being exceeded after several months of operation had elapsed.
Although the high burnup fuel assemblies had at no time exceeded the MAPLHGR value corresponding to 30,000 MWD /T, MAPLHGR limits calculated by standard licensing analysis methods showed that lower MAPLHGR values should have been utilized at the higher Again although the new MAPLHGR limits were promptly substituted, exposures.
the new limits were not at the time formally approved by the NRC.
In both cases, it was subsequently determined by the licensees that the actual operating MAPLHGR values had at no time exceeded the revised MAPLHGR limits at the higher exposures.
The licensees subsequently requested amendments to their Technical Specifications, adding MAPLHGR limits for average planar exposures values beyond the actual peak average planar exposure proiected for the present cycles.
These changes have been reviewed and apprt,ed by l
the staff.
i Additionally, fuel rod thermal-mechanical design and safety analyses for the The l
subject fuel are dependent on local (peak pellet) exposure conditions.
peak pellet exposure basis for those analyses is 40,000 MWD /T.
Since toe peak pellet exposure exceeds the fu61 assembly maximum average planar exposure as L
fuel assembly average planar exposure increases, the concern is raised that the
c IE Information Notice No. 80-04 February 4, 1980 Page 2 of 2 40,000 MWD /T fuel thermal-mechanical analysis basis exposure could also be approached or exceeded.
Investigations conducted by the licensees showed that the peak pellet exposure had not nor would not exceed the fuel thermal-mechanical design maximum basis during the current operating cycles.
The potential for occurrence of the above events can be decreased by (a) surveillance procedures which require periodic comparison of actual peak average planar exposure and peak pellet exposure values to approved exposure limits, and (b) use of the computer to provide an alarm or flag as an aid to indicate when approved exposure limits are being approached.
This Information Notice is provided to inform licensees of a significant safety matter.
It is expected that recipients will review the information for possible applicability to their facilities.
No specific action or response is requested at this time.
If you have any questions regarding this matter, please contact the Director of the appropriate NRC Regional Office.
l I
r IE Information Notice No. 80-04 Enclosure February 4, 1980 RECENTLY ISSUED IE INFORMATION NOTICES Information Subject Date Issued To Notice No.
Issued 80-03 Main Turbine Electro-1/31/80 All holders of power Hydraulic Control System reactor OLs and cps 80-02 8X8R Water Rod Lower 1/25/80 All BWR Facilities End Plug Wear holder power reactor OLs or cps 80-01 Fuel Handling Events 1/4/80 All holders of power reactor OLs and cps 79-37 Cracking in Low Pressure 12/28/79 All power reactor OLs Turbine Discs and cps 79-36 Computer Code Defect in 12/31/79 All power reactor OLs Stress Analysis of Piping and cps Elbow 79-35 Control of Maintenance 12/31/79 All power reactor facilities and Essential Equipment with an OL or CP 79-34 Inadequate Design of 12/27/79 All holders of power reactor Safety-Related Heat OLs and cps Exchangers 79-33 Improper Closure of 12/21/79 All power reactor facilities Primary Containment holding OLs and cps Access Hatches 79-32 Separation of Electrical 12/21/79 All power reactor facilities Cables for HPCI and ADS holding OLs and cps 79-31 Use of Incorrect Amplified 12/13/79 All holders of power reactor Response Spectra (ARS)
OLs and cps 79-30 Reporting of Defects and 12/6/79 All power reactor facilities Noncompliance, 10 CFR Part 21.
holding OLs and cps and vendors inspected by LCVIP 79-29 Loss of NonSafety-Related 11/16/79 All power reactor facilities Reactor Coolant System holding OLs or cps Instrumentation During Operation I
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