ML20076D315

Forwards Rev 1 to Crbr Project Heat Transport Sys In-Containment Piping Reserve Seismic Margins & Rept Re Consequences of Leaks from Small Diameter Primary Heat Transport Sys Piping

ML20076D315
Person / Time
Site:	Clinch River
Issue date:	05/19/1983
From:	Longenecker J ENERGY, DEPT. OF, CLINCH RIVER BREEDER REACTOR PLANT
To:	Grace J Office of Nuclear Reactor Regulation
Shared Package
ML20076D316	List: ML20076D315 ML20076D320
References
HQ:S:83:252, NUDOCS 8305230285
Download: ML20076D315 (2)

Text

O Department of Energy Washington, D.C. 20545 Docket No. 50-537 HQ:S:83:252 MAY 191933 Dr. J. Nelson Grace, Director CRBR Program Office Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Dear Dr. Grace:

REVISED CLINCH RIVER BREEDER REACTOR PLANT (CRBRP) PIPING SEISMIC MARGIN REPORT

References:

(1) Letter, HQ:S:83:232, J. R. Longenecker to J. N. Grace, "CRBRP Piping Seismic Margin," dated March 4,1983 (2) Letter, J. C. Ebersole to N. J. Palladino, "ACRS Report on the Clinch River Breeder Reactor Plant," dated April 19, 1983 (3) Letter, HQ:S:83:247, J. R. Longenecker to J. N. Grace,

" Primary Heat Transport System Branch Line Evaluation,"

dated April 27, 1983 Reference (1) transmitted "CRBRP Heat Transport System Incontainment Piping Reserve Seismic Margins," providing evaluations of the ability of the large i

diameter heat transport piping to withstand seismic events more severe than those required in the Federal Regulations. The CRBRP piping has been previously shown to meet all regulatory requirements concerning earthquake events at I

the CRBRP site.

In reference (2), the Advisory Committee on Reactor Safeguards raised a l concern relative to the seismic margins available in small diameter Primary Heat Transport System (PHTS) piping. The letter stressed the importance l

of assuring the integrity of the small diameter piping due to the fact that a common mode loss of piping integrity in all three heat transport system loops could disable the entire heat removal system.

8305230285 830519

ee aoom 05eoo g fp[9

2 As promised in reference (3), enclosure 1 to this letter is a revision to the reference (1) report reflecting the. seismic margins that exist for the small diameter piping and instrument penetrations connected to the heat '

transport system. ' Appendix B of the report emphasizes that, in CRBRP, design, analysis, fabrication, and inspection requirements are comparable for the large and small diameter piping.

Enclosure 2.is a report that discusses the consequences of leaks from small diameter PHTS piping. The report shows that the guard vessel elevated piping approach used in CRBRP assures adequate primary coolant inventory for any postulated primary coolant boundary leak, including a leak from small diameter piping.

Any questions regarding the enclosed reports may be addressed to Mr. D. Hornstra (FTS 626-6110) or Mr. D. Robinson (FTS 626-6098) of the Oak Ridge Project Office staff.

Sincerely, Jdhn R. Longene r Acting Director, Office of Breeder Demonstration Projects Office of Nuclear Energy 2 Enclosures cc: Service List Standard Distribution Licensing Distribution l

i i