View source for LIC-90-0741, Submits Plan for Replacement of Remaining Two Control Element Assemblies Which Contain All B4C Pellets

{{Adams
| number = ML20059G051
| issue date = 09/07/1990
| title = Submits Plan for Replacement of Remaining Two Control Element Assemblies Which Contain All B4C Pellets
| author name = Gates W
| author affiliation = OMAHA PUBLIC POWER DISTRICT
| addressee name = 
| addressee affiliation = NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
| docket = 05000285
| license number = 
| contact person = 
| document report number = LIC-90-0741, LIC-90-741, NUDOCS 9009120106
| document type = CORRESPONDENCE-LETTERS, INCOMING CORRESPONDENCE, UTILITY TO NRC
| page count = 2
}}

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Omaha PubBc Power District P.O. Box 399 Hwy. 75. North of Pt. Calhoun Fort Calhoun, NE 680234399
       .                                                            402/636-2000 1
September 7,.1990-l             LIC-90-0741 U. S. Nuclear Regulatory Commission Attn: Document' Control Desk M:il Station P1-137 Washington, DC.20555 1                                                                                                                                                                       .

==References:==
-                 1. Docket 50-285
: 2. Lettei'fromNRC-(R.F.Dudley)toOPPD(W.G. Gates) dated, July 12, 1990 Gentlemen:

==SUBJECT:==
Fort Calhoun Station Unit No. 1 CEA Replacement Plan l             InReference2,OmahaPublicPowerDistrict(OPPD)wasrequestedtosubmit within 60 days a response regarding the plan for replacement of the' remaining                                                                                                ;
twoControlElementAssemblies(CEAs)oftheoriginaldesignwhi.:hcontain                                                                                                             i all-B 4C pellets in each CEA finger.                                                                                                                                          .
1 The two CEAs in question (i.e. Numbers 47 and'48), which were inserted into the 1
core effectiveat the fullbeg,nn4.pg pevcc days of Cy(EFPD) through August 5, 1990.cle:10, have each accu Based on extensiva measurements and test data taken at Fort Calhoun Station-(FCS) for CEA strain and integrity at the end of Cycle 9 (2889 EFPD), the Maine                                                                                               i Yankee CEA failure data, and discussions with ABB Combustion Engineering,_OPPD                                                                                                ;
plans on replacing CEA. Numbers 47 and 48 before reaching 2500 EFPD.                                                                                        Present           ,
estimate for replacement of the CEAs is the end of Cycle 15, assuming there are no changes to the_ planned fuel cycle lengths or outage durations. If there is                                                                                                 l any change to the planned fuel cycle lengths or outage durations, OPPD will                                                                                                   '
adjust tae replacement dates a :ordingly to stay within 2500 EFPD.. The basis for the proposed-2500 EFPD lim.t is that forty-t.ive FCS full length CEAs of the original design were c)erated up to 2889 EFPD with no loss of integrity and no                                                                                                 i signs of cladding cracting. As indicated in Reference 2, early signs _of degradation (e.g. cracking)wereobservedatMaineYankeeforanexposureas                                                                                                            .
low as 2732 EFPD. The proposed 2500 EFPD limit for FCS is considerably less                                                                                                   1
()tji@'px'posure values to which FCS CEAs (of identical design) have been oper ited with no degradation, and it allows significant margin to the minimum exposure                                                                                                 ;
where CEA degradation at Maine Yankee has been observed.                                                                                                                      (
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3 U. S. Nacleae Regulatory _Cammission 11C-90-0741 l
Page 2 If you have .any questions or concerns regarding this response do not hesitate to contact us.                                                                                                        '   >
i Sincerely,.
1 see-ab${-sbbept3V W. G. Gates-
* Division Manager                                                                                                        I*
Nuclear Operations.
WGG/sel.
l .
c:     LeBoeuf, Lamb, Leiby & MacRae         -
A. Bournia .NRC Project Manager-                                                                                   >
R. D. Martin,'NRC Regional Administrator, Region IV                                                               i R. P. Mullikin, NRC Senior' Resident Inspector-                                                                   i 1
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