ML19256D386
| ML19256D386 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 02/22/1972 |
| From: | Maccary R US ATOMIC ENERGY COMMISSION (AEC) |
| To: | Deyoung R US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 7910180730 | |
| Download: ML19256D386 (4) | |
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~1 BHMAL iud FEB 2 21972 R. C. DeToung Assistant Director for PWR's Division of Reactor Licensing METROPOLITAN EDISON COMPANT THREE MILE ISLAND UNIT 1, DOCIET NO. 50-289 - RING CIRDER REPORT The information submitted by the subject applicant with respect to the cont =f =nt done ring girder in report on, " Containment 3milding Ring Girder, Construction and Repair," dated December 1, 1971, and in the addendum to this report dated January 21, 1972, has been reviewed and evaluated by the DRS Structural Engineering Branch. An evaluation of the information submittad to date is attached hereto.
R. R. Maccary Assistant Director for Engineering Division of Reactor Standards
Enclosure:
Evaluation for Three Mile Island Unit No. I cc w/ encl-E. Bloch, DR S. Hanauer, DR E. C. Case, DRS K. Kniel, DRL L. Shao, DRS H. Schierling, DEL Distribution:
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DRS RF R. Smith, DRS SEB RF W. Mcdonald, DEL
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THREE MILE ISLAND UNIT NO. 1 Docket No. 50-289 STRUCTURAL EVALUATION REPORT ON CONTAINMENT BUILDING RING CIRDER CONSTRUCTION AND REPAIR Reference 1. Applicant's report on "Contain=ent Building Ring Girder Construction and Repair," (Docket No. 50-289), dated December 1,1971. 2. Addendum to the above report dated January 21, 1972. Centent of Reports The above cited reports give a general descriptica of concrete voids that resulted during construccica of the Contain=ent Building Ring Girder for Unit No.1 of the Three Mile Island Nuclear Station. They also present in detail the corrective actions which the applicant intends to i=plement. Conclusion Based on the infor=ation contained in the above referenced documents, we have concluded that the repaired ring girder should be capable to withstand the design loads which may be applied to the structure during its life time provided special attention is given to the items listed in the Appendix. It is suggested that this listing be forwarded to the applicant for consideration with respect to the repair plans proposed; it should be fully imple=ented by the applicant. 1453 274
APPENDIX 1. Special attention shoc.'d be given to quality assurance and quality control. [ 2. Six samples of concrete-epoxy-concrete jointo should be prepared and stored in envircnment similar to the one obtaining in the ring girder. Three of these samples should be tested for tensile and shear strength af ter one year and three samples af ter three years af ter initial start-up. The tests should show that the i epoxy joints have a strength better than or at least equivalent to the concrete strength. The results of these tests should be referred to the Cocsission within 10 days. 3. Install pernanent structural provisions to facilitate access to the ring girder and dome area for the purpose of inservice inspe ctions. 4. Conduct gage readings and visual. inspection during the prestressing operations, during the acceptance and leak tests and 6,12, 24 and 36 months after the acceptance test. These examinations should be perfor=ed by cocpetent inspectors and with the aim of uncovering evidence of structural distress. Crack patterns should be recorded during each inspection. During the acceptance test the procedure indicated in the AEC Safety Guide #18 should be followed and in addition strain gage readings and visual inspection shculd be =ade as suggested by the applicant in the referenced reports. 1453 275
_2 5. Submit to the Commission detailed reports of the results of the surveillance program within 10 days af ter the completion of those aspects of the program scheduled to be ccaducted at prestressing, at acceptance test, and at 6,12, 24 and 36 months af ter the initial containment Icak rate test. These reports will be used for the purpose of review and possible revision of the inservice surveillance program. 6. If a final vaather-proofing treatment of the top surface of the ring girder and of the done is used, the insulating characteristics of the weather-proofing caterial (to reduce the thermal gradients) as well as its ability to acce=modate development and movement of cracks in the cencrete surface of the do=e should be carefully developed and specified. This weather-prooff ag should be such as to permit the visual inspection of concrete crack patterns. r 1453 276 .}}