ML20028D244

Updated LER 80-009/01T-1:on 800414,primary to Secondary Leak of Approx 0.5 Gpm Detected in B Steam Generator,Exceeding Tech Spec Limit.Caused by Leaking Tubes.Leaks Repaired by Explosive Plugging

ML20028D244
Person / Time
Site:	Robinson
Issue date:	01/07/1983
From:	Cox H CAROLINA POWER & LIGHT CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20028D235	List: ML20028D234 ML20028D244
References
LER-80-009-01T, LER-80-9-1T, NUDOCS 8301170258
Download: ML20028D244 (2)

Text

NRC F ORM 366 UPDATE REPORT - PREVIOUS REPORT DATED U. S. NUCLEAR REGULATORY COMMISSION U7 APRIL 28, 1980

, LICENSEE EVENT REPORT (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION)

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/ H 60 61 DOCK ET NUVBE R 68 69 EVENT DATE 74 7S REPORT DATE EVENT DESCRIPTION AND PROBABLE CONSEQUENCES Oio y g ;7; {n April 14, 1980, while Unit #2 was in the process of cooling down to inspect the j "C" Reactor Coolant Pump, a primary to secondary leak of approximately 0.5

,g,,, {eals on l This exceeded the maximum allowable

,9,,, fPMwasdetectedin"B"SteamGenerator(S/G). l g,,j ; teak rate per S/G (0.35 GPM) permitted by Tech. Spec. 3.1.5.3. The Eddy Current y qq f nspection results placed all three S/Gs in the C3 category as defined by Tech. Spec. g Th ese circumstances constitute a reportable event in accordance with gg,,, f.2.5.1.2.b. l

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, 3 ;o; [ Tube sheet inspections revealed f our tubes with small but ident ifiab le leaks. The l g,yij gleaks were repaired by explosive plugging. The cause for tube failures was investi- l

, , , . , , ggated and reported in the Steam Generator Inspection and Safety Evaluation Report j g,;3j l dated April 29, 1980 as required by Technical Specification 4.2.5.3.3. l 11 141 l l 7 ft 9 80 ST vPOWER OTHER ST ATUS ISCO HY DISCOVERY DESCRIPTION i 5 W @ l0l0l0lgl N/A l l A gl Operator Observation l A IW TY CO%'T E N T HE LF ASE D OF Hf L F ASE AMOUNT OF ACTIVITY LOC ATION OF RELEASE N/A N/A l1 l6 l W @ ]Ql 1 H 9 10 11 44 l l 45 80 l

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SUPPLEMENTAL INFORMATION FOR LICENSEE EVENT UPDATE REPORT 80-009, REVISION 1 I. Cause Description and Analysis At 1156 hours0.0134 days <br />0.321 hours <br />0.00191 weeks <br />4.39858e-4 months <br /> on April 14, L980, while Unit #2 was in the process of slmtting down to inspect the seals on "C" Reactor Coolant Pump, a sample test of steam generator water revealed a primary to secondary leak of an undetermined size. Further extensive testing and evaluation revealed by 2130 hours0.0247 days <br />0.592 hours <br />0.00352 weeks <br />8.10465e-4 months <br /> on April 14, 1980, that a primary to secondary leak of approximately 0.5 GPM existed in "B" Steam Generator. Th is exceedel the maximum leakage per steam generator of 0.35 GPM allowed by Technical Specification, Se ct ion 3.1. 5. 3. Cooldown operations, which had been suspended in order to verify the steam generator leak rate, were therefore immediately recommenced at 2L30 hours on April 1.,

1980. The unit was in cold shutdown at 1245 hours0.0144 days <br />0.346 hours <br />0.00206 weeks <br />4.737225e-4 months <br /> on April 15, 1980.

As a result of visual and Eddy Current inspections, as required by Section 4.2.5 of the Technical Specifications, four defective steam generator tubes were id ent if ied . The cause for these failures was investiga ted and a followup report, as required by Section 4.2.5.3.3 of the Technical Specifications, was submitted detailing the results of the inve s t iga t ion . Also, the results of this inspection were combined with the results of a previous inspection, performed in March, 1980, to equal a 100% examination. The results of the combined inspe ct ions placed all three steam generators in the C-3 category as defined by Technical Specification 4.2.5.1.2.b. Specifically, the results indicated that 1.6% , 2. 5% , and 1. 4% of the tubes sampled (100%) we re defective for "A", "B", and "C" Steam Generators res pe ct ive ly.

Iloweve r , these results, although submitted in the above ref erenced followup report , we re not reported as a LER in accordance with Technical Specification Table 4.2-2. This report is, therefore, submitted to revise the original LER to include the inspection results.

II. Correct ive Action The primary system was drained to below the generator channel head, and j the secondary side was drained to the tube sheet. The defective tubes were plugged and verified as leak-tight by leak test.

III . Co rrect ive Ac tion to Prevent Recurrence The Eddy Current testing program, required by Technical Specifications, i

was pe rf ormed and the defect ive tubes were plugged in order to prevent l the development of leaks. Further corrective action will be taken if inve s t iga t ions and evaluations indicate its necessity.

l Regarding the failure to appropriately report, it is believed that l the unusual nature of this ins pe ct ion , two separate and distinct Eddy l Current tes ts being combined , resulted in the oversight with respect to the results' ca t ego ry . This aspect of the event is therefore considered an isola ted case involving circumstances of a one time na tu re and , a s su ch , requires no further corrective action.

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