ML19260C848
| ML19260C848 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 01/25/1980 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Dewitt R CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| References | |
| NUDOCS 8002060245 | |
| Download: ML19260C848 (1) | |
Text
pa arag#'o UNITED STATES
' 'j'p
' / '4
/,7, NUCLEAR REGULATORY COMMISSION i
k3,,( I 3
- k'-'-((*E REGION lli n
o, 799 ROOSEVELT ROAD O
- U GLEN ELLYN, ILLINOIS 60137 g
Docket No. 50-155 Consumers Power Company ATTN:
Mr. R. B. DeWitt Vice President Nuclear Operations 212 West Michigan Avenue Jackson, MI 49201 Gentlemen:
This Information Notice is provided as an early notification of a possibly significant matter.
It is expected that recipients will review the infor-mation for possible applicability to their facilities.
No specific action or response is requested at this time.
If further hPC evaluations so in-dicate, 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, L
a py h$p w a
mesG.KeppIer Director
Enclosure:
IE Information Notice No. 80-02 cc w/ encl:
Mr. D. P. Hoffman, Nuclear Licensing Administrator Mr. C. J. Hartman, Plant Superintendent Central Files Director, NRR/DPM Director, NRR/ DOR PDR Local PDR NSIC TIC Ronald Callen, Michigan Public Service Commission Myron M. Cherry, Chicago s002060Q W 9
SSINS:
6870 Accession No:
UNITED STATES 7912190654 NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT
[f[lG rjrg WASHINGTON, D.C.
20555 "lil'fllllfh !llY; ! }['
9!g January 25, 1980 IE Information Notice No. 80-02 8X8R WATER ROD LOWER END PLUG WEAR On October 3, 1979, Vermont Yankee Nuclear Power Corporation (VY or Licensee) reported (LER-79-25/IP) observance of lower end plug wear on the water rods of 8X8R demonstration fuel assemblies.
These observations were obtained during refueling outage inspections.
Subsequent to the initial LER, the Licensee issued LER 79-25/IT on October 17, 1979, which provided more detailed descrip-tions of the probable cause and corrective action associated with this event.
The lower end plug wear was isolated to the water rods of the 8X8R fuel assemblies.
The cause of the wear was attributed to flow excitation of the water rods by coolant cross flow within the lower tie plate flow volume.
The repetitive contact of the Zircaloy lower end plug with the stainless steel lower tie plate resulted in preferential wear of the softer Zircaloy end plug.
No significant wear was observed in the lower tie plate.
To provide in reactor experience on the modification proposed to mitigate lower end plug wear, the Licensee will include four modified 8X8R fuel bundles in their upcoming cycle of operations.
The primary modification consists of using two capture water rods with shorter lower end plugs to eliminate the flow-induced excitation.
Two of these fuel assemblies were previously irradiated.
The staff was informed that VY plans to perform surveillance on these four modified bundles at the next refueling outage.
The surveillance will confirm the efficacy of the modifications and the currently estimated rate of wear.
Based on evaluation of the lower end plug wear rates, and the absence of any indicated rotational movement of the water rods with worn lower end plugs, General Electric Company (GE) and the Licensee have concluded that no addi-tional corrective action is warranted at this time.
To support this conclusion, on December 11, 1979, VY and GE presented detailed status of their evaluations and analyses of this condition to the NRC staff.
As a result of the information provided in the December 11, 1979 meeting, the staff agreed with the conclusion that no additional corrective action is warranted at this time.
The staff requested that GE document and formally submit proprietary, and nonproprietary versions of their evaluations and analysis.
In addition, the staff requested the Licensee to submit a supplement to the earlier LER's considering the potential for loose parts.
gC
IE Information Notice No. 80-02 January 25, 1980 Page 2 of 2 To provide additional confirmatory evidence supporting the findings by GE and the Licensee, GE will develop a surveillance program specifically addressed at inspections for wear of the lower end plugs.
When this program is developed, GE will propose the program to the NRC staff.
BWR Licensees are encouraged to participate in a surveillance program on this matter.
This Information Notice is provided as an early notification of a possibly significant matter that is still under review by the NRC staff.
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.
Attachment:
List of Recently Issued IE Information Notices
\\}
IE Information Notice No. 80-02 Enclosure January 25, 1980 RECENTLY ISSUED IE INFORMATION NOTICES Information Subject Date Issued To Notice No.
Issued 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 79-28 Overloading of Structural 11/16/79 All power reactor facilities Elements Due to Pipe Support with an OL or CP Loads 79-27 Steam Generator Tube 11/16/79 All power reactor facilities Ruptures At Two PWR holding OLs and cps Facilities
\\ Qh