View source for B12089, Requests Temporary Waiver of Compliance from Tech Spec 3.3.D Limiting Condition for Operation for Tube 37-73 in Steam Generator 2.Justification Listed.Tube Will Be Plugged During Next Inservice Insp

{{Adams
| number = ML20197E546
| issue date = 05/07/1986
| title = Requests Temporary Waiver of Compliance from Tech Spec 3.3.D Limiting Condition for Operation for Tube 37-73 in Steam Generator 2.Justification Listed.Tube Will Be Plugged During Next Inservice Insp
| author name = Mroczka E, Opeka J
| author affiliation = CONNECTICUT YANKEE ATOMIC POWER CO.
| addressee name = Grimes C
| addressee affiliation = NRC OFFICE OF NUCLEAR REACTOR REGULATION (NRR)
| docket = 05000213
| license number = 
| contact person = 
| document report number = B12089, NUDOCS 8605150278
| document type = CORRESPONDENCE-LETTERS, INCOMING CORRESPONDENCE, UTILITY TO NRC
| page count = 2
}}

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or CONNECTICUT YANKEE ATOMIC POWER COMPANY BERLIN. CONNECTICUT P o BOX 270   HARTFoRo CONNECTICUT 06141-0270 TELEPHONE 203-665-5000 May 7,1986 Docket No. 50-213 B12039 Office of Nuclear Reactor Regulation Attn:       Mr. C. I. Grimes, Director Integrated Safety Assessment Project Directorate Division of PWR Licensing - B U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Gentlemen:
Haddam Neck Plant Temporary Waiver of Compliance From Technical Specification Limiting Condition for Operation (LCO)
On May 6,1986, during preparation of the Haddam Neck Steam Generator Tube Inservice Inspection Final Report, it was discovered that a tube at Row 37, Column 73 (Tube 37-73) of the #2 Steam Generator should have been plugged during the recently completed refueling outage. A transcription error during the evaluation of the eddy-current test data for this tube resulted in the tube at Row 37, Column 33 (Tube 37-33) being plugged by mistake. Tube 37-73 has a small diameter pit that is 55% of the nominal tube wall thickness. The plugging limit, as defined in Specification 4.10.I, is greater than or equal to 50% of the nominal tube wall thickness. Further data verification has shown this to be a unique error. A Licensee Event Report will be filed withia 30 days of this event describing corrective actions to the data verification procedures to prevent recurrence.
The Haddam Neck Plant was in Mode 2 upon discovery of this error on the af ternoon ef May 6. The #2 reactor coolant system (RCS) loop isolation valves
         . were closed later that day to isolate the inoperable #2 steam generator from the RCS and to bring the plant back into compliance with Technical Specification 3.3.0. This action will allow low power physics testing to continue with the turbine on-line scheduled for May 9,1986.
In accordance with recent discussions between CYAPCO and the NRC Staff, the Connecticut Yankee Atomic Power Company (CYAPCO) hereby requests a temporary waiver of compliance from Technical Specification 3.3.D for Tube 37-73 in the #2 Steam Generator. CYAPCO has determined that operating in excess of the technical specification LCO until an emergency amendment is processed will not place the plant in an unsafe condition. The basis for this determination is:
0

r s .s (1)   the pluggable flaw in tube 37-73 (55 % through-wall thickness) has been determined to be a small diameter pit (approximately 80 mils).
(2)   the progression rate of this type flaw at Haddam Neck is currently estimated to be less than 10% through wall per cycle.
(3)   the progression rate on this flaw during the last cycle was approximately 6 percent.
(4)   implemented, secondary water chemistry improvements should further reduce the estimated pitting progression rate.
(5)   the defect has been evaluated and found acceptable in accordance with Regulatory Guide 1.121 for this cycle.             The evaluation includes conservative estimates of flaw growth and tube strength.
,       Prompt relief is requested in order to minimize the duration of three-loop l       operation and the resulting impact on the power ascension program. CYAPCO will submit in the near future an emergency license amendment request regarding Technical Specification 4.10.1 to minimize the duration of time under
;       which CYAPCO will be operating under the provisions of the subject waiver.
CYAPCO has a high confidence that Tube 37-73 will not fait during the upcoming cycle of operation and that the reliable operation of all four steam generators has been adequately assured. Nevertheless, Tube 37-73 will be plugged during the next inservice inspection of the steam generators which will take place during the 1987 refueling outage. Accordingly, the forthcoming amendment request will be applicable only for the period of cycle 14 operation. Furthermore, additional man-rem exposure would be incurred to plug this tube at this time versus at the next scheduled inservice inspection. Such action would not be in keeping with the ALARA philosophy. CYAPCO will, of course, shutdown and repair the steam generators if at any time the allowable primary to secondary leakage exceeds existing Technical Specification limits.
This issue will be reviewed and concurred in by the PORC and the Haddam Neck Plant NRB prior to unisolatfng RCS toop 2.                                       ,
We will continue to keep you informed regarding our progress on submitting the formal amendment request.
Very truly yours, CONNECTICUT YANKEE ATOMIC POWER COMPANY i
l J K Opsxi9 J. F. Opeka Senior Vice President
                                                                /2/C   J l                                            By: E. J./jiroczlla   #
Vice PreMdent Attachment ~
cc:   Dr. T. E. Murley
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