ML19224C454
| ML19224C454 | |
| Person / Time | |
|---|---|
| Issue date: | 06/20/1979 |
| From: | James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | Wright G ILLINOIS, STATE OF |
| References | |
| NUDOCS 7907020406 | |
| Download: ML19224C454 (1) | |
Text
[o Ma,
n u
'o, UNITED STATES 8 ' ' 3.,,
j NUCLEAR REGULATORY COMMISSION g
3-
~y..
s REGION 111 4
o, 8
799 ROOSEVELT ROAD
\\.'.\\#
GLEN ELLYN ILLINOIS 60137 y
JUN 211979
~
State of Illinois Department of Public Health ATTN:
Mr. Gary N. Wright, Chief Division of Nuclear Safety 535 West Jefferson Street Springfield, IL 62761 Gentlemen:
The enclosed IE Information Notice No. 79-17 titled " Source Holder Assembly Damage from Misfit Between Assembly and Reactor Upper Grid Plate" was sent to the following licensees on May 29, 1979, for information:
American Electric Power Service Corporation Indiana and Michigan Power Company D. C. Cook 1, 2 (50-315, 50-316)
Cincinnati Gas & Electric Company Zimmer (50-358)
Cleveland Electric Illuminating Company Perry 1, 2 (50-440, 50-441)
Commonwealth Edison Company Braidwood 1, 2 (50-456, 50-457)
Byron 1, 2 (50-454, 50-455)
Dresden 1, 2, 3 (50-10, 50-237, 50-249)
La Salle 1, 2 (50-373, 50-374)
Quad-Cities 1, 2 (50-254, 50-265)
Zion 1, 2 (50-295, 50-304)
Consumers Power Company Big Rock Point (50-155)
Midland 1, 2 (50-329, 50-330)
Palisades (50-255)
Dairyland Power Cooperative LACBWR (50-409)
Detroit Edison Company Fermi 2 (50-341)
Illinois Power Company Clinton 1, 2 (50-461, 50-462)
[} hb q 90'g 020906 qKjQRIM M
JUN 211979 State of 111inois.
Iowa Electric Light & Power Company Duane Arnold (50-331)
Northern Indiana Public Service Company Bailly (50-367)
Northern States Power Compa,y Monticello (50-263)
Prairie Island 1, 2 (Ra-282 50-306)
Tyrone Energy Park 1 (50,;4)
Public Service of Ini tana Marble Hill 1, 2.a0-546, 50-547)
Toledo Edison Com any Davis-Besse 1 (>0-346)
Union Electric C mpenv Callaway 1, 2 (50-3, 50-486)
Wisconsin Elec ric Power Company Point Beach, 2 (50-266, 50-301)
Wiscon.in Pub ic Service Corporation Kewaunee (' J-305)
Sincerely, k kn]
/ p' M &
Helen Pappas, Chief Administrative Branch
Enclosures:
IE Information Notice No. 79-17 cc w/encls:
Mr. D. W. Kane, Sargent & Lundy Central Files Reproduction Unit NRC 2Gb Local PDR NS1C TIC 271 287
U.S. NUCLEAR REGULATORY COMMISSION OFFICE CF INSPECTION AND ENFORCEMENT REGION III June 20, 1979 IE Infomation Notice No. 79-17 SOURCE HOLDER ASSEMBLY DAMAGE FROM MISFIT BETWEEN ASSEMBLY AND REACTOR UPPER GRID PLATE Description of Circumstances:
Recently, the NRC was infomed of a problem at two Westinghouse PWR facilities resulting from an apparent misfit between secondary source holder assecblies and the reactor upper grid plate.
The nisfit problem was first identified by Carolina Power & Light, licensea for H. B. Robinson Unit 2, who infomed the NRC on day 6,1979, of the circum-stances. During the current refueling outage at H. B. Robinson 2, CP&L deter-n ned that two secondary source holder assemblies had been damaged during the previous refueling in February 1978, by a mistit between the assembly and the reactor upper grid plate. The misfit resulted from insufficient clearance (i.e. 1/2 to 3/4 inch) between the source holder assembly hub and the grid plate at the core locations containing thermocouple mixing vanes. This lack of sufficient clearance caused minor defomation of the upper grid plate com-ponents at the core location and of the source holder essemblies. The deforma-tion also resulted in same bending of the fuel rods in the assembly, however, in no case did this bending result in fuel cladding perforation.
On May 16, 1979, the licensee M D. C. Cook Unit 1 informed the NRC that the present refueling outaga woula oe extended 15 to 20 days to remove the reactor head, which had already been reinstalled following completion of refueling, to correct this misfit problem. They learned of.the problem from Westinghouse.
Subsequently, the licensee's inspection revealed that the source holder assembly hubs were in contact with the vanes. The source holder was removed from one assembly readily with no apparenc damage while in the other the source holder was found stuck in the assembly. The problem was corrected prior to return to operations.
The secondary source ascembly rods are normally inserted into rod cluster control assemblies and ple:ed at symma.trical locations in the core. Each such assembly contains a symmetrical grouping of four secondary source rods and between zero and twenty burnab h poison rods. Locations in the assembly not filled with a source or burnable. poisqiim d =May,AMir @w.
Thg_ lack r
ofsufficientcleeranceforthesesoud DUPLICATE DOCUMENT onlyatthecorelocationswhichcot.q1 271 288 i
- 2ntire document previously entered into system under
40GMOMO ANO No. of pages:
h
~