ML20117P222

Forwards Final Rept Thermal Properties of Concrete at High Temps, Dtd 940217

ML20117P222
Person / Time
Site:	05200004
Issue date:	01/27/1996
From:	Recasha Mitchell GENERAL ELECTRIC CO.
To:	Sheron B NRC (Affiliation Not Assigned)
Shared Package
ML20117P224	List: ML20117P222 ML20117P229
References
NUDOCS 9609200340
Download: ML20117P222 (4)

Text

( GPO*Y GENuclear Energy l Gener31Rectnc Company 175 Curtnct Annue. San Jose CA 95125 January 27,1995 l

Brian W. Sheron )

- Director Division of Engineering Nuclear Reactor Regulation Nuclear Regulatoly Commission Mail Stop 07E25 Washington, DC 20555

Subject:

Transmittal of Requested Documentation Reference. Kontani and Shah, Report of Thermal Properties of Concrete at High l Temperature, NSF Center for Advanced Cement Based Materials, Northwestern University, (Final Report) February 17,1994. ,

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Dear Dr. Sheron,

This letter transmits the reference report as you requested (telecon with Jim Quinn of January 17,1995). It should be clearly noted that the report does not form part of the i SBWR design basis documentation. Further GE does not endorse the report, but we are ,

providing it to the NRC at your request. We wish to provide you some background on this l report and some cautions related to its use.

This report was prepared by the NSF Center for Advanced Cement Based Materials, 1 Northwestern University, based on work performed between August 1992 and January j 1994. The contract for this work was administered and monitored by Burns and Roe. The i study was commissioned by GE Nuclear Energy to support conceptual studies of the i SBWR program.

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. - SBWR employs a passive system for containment heat removal. Using this passive s; . tem, the containment temperature may be as high as 170 c. Previous studies of concrete exposed to high temperature indicated that, over a period of days, this might lead to increased pressure behind the liner plate due to non-condensable gases and steam released from the concrete. This raised a concern that, after the containment was depressurized, the strains in the liner plate might exceed the ASME allowable limits. In contrast, earlier plant designs use containment sprays to keep the containment temperature low. Therefore, this concern does not relate to design basis conditions in earlier designs.

One of the possible design alternatives studied to prevent damage to the liner was the use of dry (Iow water cement ratio) concrete for the containment structure. To obtain insight

! into this idea, testing was performed using low water cement ratio concrete as l documented in the referenced report. Note that the test does not simulate the containment configuration or conditions, rather they duplicate a previous test program. It was observed g that the water cement ratio has little effect on pressurization. The conclusion of the study s Q g 9609200340 960127 PDR ADOCK 05200004 A PDR

was that there appears to be sufficient quantities of gel water, chemically bound water, and aggregate absorbed water that pressurizrtion may occur above 105 c. Note that low water cement ratio concrete is not being pursued funher for the SBWR.

It should be understood that, although the results of the test program were helpful to GE in deciding to pursue an alternate design strategy, GE does not endorse the report for design application. There are technical concerns with the report and it does not meet GE quality standards. The technical concerns include the following:

1. There is considerable discussion of the uncertainties related to instrumentation and calibration problems which were encountered during the study, but the main report does not clearly indicate whether these issues were resolved for the fmal testing, nor does it indicate any impact they may have had on the results.

2. The bulk of the report documents theoretical study of concrete pressurization under high temperature conditions. Although a number of hypotheses are made regarding the differences between the theoretical and experimental results, there is little efTort to determine if the hypotheses could explain the differences, nor is a path for the resolution of the issues discussed. It is simply stated that the problem is diflicult and the cause for the differences cannot be determined.

Since there is no suggested path to resolution of the differences between the theoretical and experimental results, and since the test conditions are not typical of conditions in either operating reactors or reactors now under design, GE does not feel that the report, in its current form, is useful for assessing design basis or severe accident conditions in a nuclear power plant. Although we would not normally release this report without resolving these technical concerns, it is being given to the NRC at their request and with these stated reservations.

Very Tnily Yours, m c.M Robert C. Mitchell Manager, Safety Evaluations cc: C. E. Buchholz R.11. Buchholz S. A. Delvin P.F.Gou M. IIerzog S. A. Ilucik l J. E. Leatherman l J. E. Quinn  !

l J. F. Quirk M. A. Smith 4

9 pq Burns and Roe Company MM 5: $?b? .N:N?.5:S:N$$ :.w e ev=u =.E ;u SBWR COMMUNICATION TRANSMITTAL Tvoe of Communication BRC

Reference:

BRG- 0336 X Courier or Mail Date: February 22,1994 Facsimile No.

Facsimile No. and Courier Mail Page 1 of _ Pages TO: Mr. R.H. Buchholz, M/C 781

SUBJECT:

GE Nuclear Energy W.O.6528 SBWR - US Programs SBWR 175 Curtner Avenue Contract SBWR 9004 San Jose, California 95125 Attention: ACBM -

CONCRETE TSTING FINAL REPORT PURPOSE / REQUESTED ACTION:

() Design input (x) Information

() Review / Comment () Concurrence TASK NUMBER:

() Reference

() Other WBS NUMBER: 3.6.1.2 RESPONSE DUE (DATE): MPL NUMBER:

Comments:

Response to comments made on previous drafts will be addressed in a separate letter.

DOCUMENTS ENCLOSED: DISTRIBUTION:

BR (Internall GE (External)

Title:

Document No: PM LAZuchowski PM RHBuchholz Rev. No: GS (N) CABillani WGM MAHerzoa (3)

Date: GS (C/S)RAPixlev (2) TPE ENa Other LE Pearson/ File PGou CC: Dr. Sushil Chandra ORIGINATOR: Bur s and Roe Company Bechtel Corporation adell, .

50 Beale Street C San Francisco, California 94119 Mr. Glenn Schaefer (Per telephone conversation Leon A. Zu wski, Jr.

W.R. Grace 8/23/93 with R. Pixley) ro' anager 62 Whittenmore Cambridge, Massachusetts 02140

k y Burns and Roe Company M eac sncemamac noac ocaw res wsev :. en w,::t 2e5 2002 nr :r: se3 ,a: re.e 2150ss cao.e BP.s niOc~

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Subject:

W.O.6528 l Simplified Passive Advanced Light Water Reactor Program (SBWR)

P.O. #190 SBWR-L9004 WBS 3.6.1.2 Thermal Properties of Concrete at High Temperature ACBM Test Report - Finalissue February 22,1994 BRG - 0336 Mr. R.H. Buchholz, M/C 781 GE Nuclear Energy SBWR - US Program 175 Curtner Avenue San Jose, California 95125 Attention: M. A. Herzog

Enclosure:

(A) Kontani and Shah, Report of Thermal Properties of Concrete at High Temperatures, NSF Center for Advanced Cement Based Materials, Northwestern University, (Final Report) February 17,1994

Dear Ms. Herzog:

Enclosure ( A) provides the Final Report from Northwestern's University's Center for Advanced Cement Based Materials performed for the SBWR project. ACBM has received and incorporated the comments made by the other SBWR Team Members directly in the report to the greatest extent possible. More Details on the specific responses to the various comments will be addressed by separate letter.

If you have any questions, please do not hesitate to call me.

Ve ' tru urs, r-

.A.ZUCHO Ki

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