ML19291C273

Comments on Lll Rept, Seismic Analysis of Acid Liquid Waste Tanks at Western Ny State Nuclear Svc Ctr,West Valley,Ny. Analysis Provides Only Estimate of Strength Available to Resist Specified Loadings

ML19291C273
Person / Time
Site:	West Valley Demonstration Project
Issue date:	05/25/1979
From:	Hall W NATHAN M. NEWMARK CONSULTING ENGINEERING SERVICES
To:	Clark A NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS)
Shared Package
ML19291C263	List: ML19291C265 ML19291C273 ML19291C279 ML19291C281
References
CON-NRC-03-78-150, CON-NRC-3-78-150 NUDOCS 8001230257
Download: ML19291C273 (3)

Text

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NATHAN M.

NEWMARK CoNSUI. TING ENGINEERING SERVICES 1211 CIVIL ENGINEERING BUILolNG URBANA. lLLJNolS 618o1 25 May 1979 Dr. A. T. Clark Fuel Reprocessing and Recycle Branch Division of Fuel Cycling and Material Safety U.S. Nuclear Regulatory Commission Washington, DC 20555 Re: Contract NRC-03-78-150, NMSS Report " Seismic Analysis of the Acid Liquid Waste Tanks at the Western New York State Nuclear Service Center, West Valley, New York" by C. Y. Liaw, A. M. Davi to and R. C. Murray, Lawrence Livermore Lab. Report UCRL-52600, March 1979

Dear Dr. Clark:

As part of our work assignment with your branch we have been asked to provide review comments concerning the results of the detailed seismic and wind evaluation studies of the nuclear fuel reprocessing plant operated by Nuclear Fuel Services, Inc. at West Valley, N.Y.

This report provides summary review comments on the study pertaining to the NF5 plant acid liquid waste tanks, as referenced above.

I had occasion to observe the facility generally during a site visit on 20 March 1978 in the company of NRC and LLL staff, and have participated in a number of meetings, as well as telephone conversations, during 1977 and 1978 with NRC and LLL personnel where various aspects of the analyses being carried out were discussed.

At this point it should be noted that it is extrecely di fficul t to analyze in detail complicated and interconnected structures of tne type being studied in the referenced report. At best, analyses of any type, including sophisticated analyses such as those summarized in the noted repo'et, can a

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2 provide only an estimate of the strength available to resist the specified loadings. My review comments are directed toward attempting to place in perspective the significance of the findings, based on the information contained in the report, as well as my experience in dealing with the seismic and wind resistance of similarly constructed facilities.

My comments on the referenced analysis report follow.

The noted report contains a study of the seismic adequacy of two acid waste tanks (80-3 and 8D-4) located in a rectangular reinforced concrete vault. Each tank is 12 f t in diameter, 15.75 ft in height, made of 304 L stainless steel, and has a nominal capaci ty of 15,000 gal. The. tanks are supported on legs of 8 in. extra strong pipe fastened to the bottom of the vault.

The reinforced concrete vaul ts are 32 f t by 19 f t by 25,25 f t high, with the floor slab extending out beyond the walls. A stainless steel liner covers the floor and extends up the wall 1.5 f t, creating a pan under the tanks.

The analysis of the tanks and vault was made with a finite element program (SAP 4) and included consideration of dead loads, hydrostatic loads (one tank is nearly full), thermal loads and seismic loads (0.20 g zero period ground acceleration and NRC Reg. Guide 1.60).

In the.ase of the & xs the analysis was made to ascertain there was no difficul ty for yielding or buckline of the shell wall, yielding of the bottom plate, or yielding or buckling of the supoort legs and stiffeners.

Several analyses incorporating different loading situations v are made. Even for the low damping value employed (one percent of cri tical) the maximum stress in the tank wall occurred near the legs and was found to be about 40 percent.

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3 of yield. The highest stress (in excess of yield) was found to occur in the base plate connecting the legs to the support assembly and suggests that yielding may occur but yet not impair the support function.

Interaction effects are probably low in view of the fact that the tank legs are tied directly to the foundation slab.

In the case of the vault the analysis necessarily included equivalent static analysis of the soil pressures along with finite element analysis of the vaul: itself. The principal ccmpiication in carrying out the vaul t analysis centered around treatment of the thermal loadings. The analyses made suggest that some cracking of the vault may occur if the thermal gradient is very great. An elastic analysis, as undertaken here, is unable to offer more than an approximate insight into the nonlinear effects associated with the residual thermal loading, in view of the probability of at least some thermal gradient existing, it is qui te likely that at a cero period acceleration of 0.20 g cracking of the reinforced concrete vaul t can be expected at the roof wall junction; cracking in this cone would not be expected to lead :o leakage of any fluids.

Respectfully submi:ted, l)

-l A U W. J. Hall p9 Distribution:

Addressee - 2 Winston Burkhardt - 1 N. M. Newma rk - 2 W. J. Hall - 2 1792 237'

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