ML20147D364

Forwards Request for Addl Info for Rev of Subj Facil FSAR

ML20147D364
Person / Time
Site:	Salem
Issue date:	10/06/1978
From:	Parr O Office of Nuclear Reactor Regulation
To:	Mittl R Public Service Enterprise Group
References
NUDOCS 7810140040
Download: ML20147D364 (6)

Text

. _ _ _ _ _

, fA 4/ UNITED STATES

• O,w ./t NUCLEAR REGULATORY COMMISSION I. ), j WASHl. 3 TON. D. C. 20555 N.?:../ NRC PDit OCT 0 61978 Docket No. 50-311 Mr. R. L. Mittl General Manager - Projects Engineering and Construction Department Public Service Electric and Gas Company 80 Park Place Newark, New Jersey 07101

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION FOR THE REVIEW 0F THE SALEM UNITV25fdNAL SAFETY ANALYSIS REPORT (FSAR)

As a result of our continuing review of the Salem FSAR, we find that we need additional information to complete our evaluation.

The specific information required is listed in the Enclosure.

Our review schedule is based on the assumption that this additional information will be available for our review by October 20, 1978. If you cannot meet this date, please inform us so that we may revise our schedule accordingly.

Please contact us if you desire any discussion or clarification of the enclosed request.

Sincerely, 0 . arrDhief Light Water Reactors Branch No. 3 Division of Project Management

Enclosure:

Request for Additional Information cc: See next page 1 8 W M 96 A $

Mr. R. L. Mittl OCT 0 61978 cc w/ enclosure:

Richard Fryling, Jr. , Esq.

Assistant General Counsel Public Service Electric & Gas Company 80 Park Place Newark, New Jersey 07100 Mark Wetterhahn, Esq.

Conner, Moore & Cober 1747 Pennsylvania Avenue, N.W.

Suite 1050 Washington, D. C. 20006 Mr. Leif J. Norrholm U. S. Nuclear Regulatory Commission Region I Drawer I Hancocks Bridge, New Jersey 08038 l

l

REQUEST FOR ADDITIONAL INFORMATION SALEM NUCLEAR GENERATING STATION UNIT 2 DOCKET NO. 50-311 5.106 In our request for additional information 5.8B we raised a concern which is related to the postulated tornado phenomenon, '

focusing on the method used by you in combining the induced loads and how this resultant load is combined with other loads in the various load combinations considered for the design of Category I structures. Your response indicated that all three loads (wind pressure, pressure differential and postulated-tornado-missiles) were considered in the design of Category I structures and that the resultant load was used in conjunction with other loads in case D of the

• load combination. However, you did not state how these three load were combined to generate the resultant total tornado load. Having established the effective loads for each of the above three individual tornado-generated effects, the combination thereof should then be determined in a conservative manner for each particular Category I structure, as applicable. An acceptable method of combining these effects is the following:

(i)Wt+Ww b (ii) Wt"W p (iii) Wt"Nm (iv) Wt"N w +.5W p (v) Wt" w * "m ,

(vi) Wt " "w + . 5 W p +W m where: Wt . . . . . total tornado load, Wg. . . . . tornado wind load, W p . . . . . tornado differential pressure load, and Wm . . . . . tornado missile load.

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-2 For each particular structure or portion thereof, the most adverse of the above combinations should be used as appropriate, These combined effects constitute the total tornado load, which should then be combined with other pertinent loads as specified in applicable load combinations. You should state if the method used for combining the three tornado related loads meet the above criteria. In the event that your criteria differ ,.

from those identified above, you should discuss how your proposed criteria compare with the criteria acceptable to us by indicating the relative degree of conservatism.

5.107 In request for additional information 5.94 we asked you to provide a comparison of the response spectra and damping values utilized in your seismic analysis with those specified in Regulatory Guides 1.60 and 1.61. We also asked you to determine if the combined effect of the use of your spectra and damping values afforded the same degree of conservatism as that resulting from the combined use of R.G.1.60 and 1.61. -

You compared the damping values used in your design with those _

identified in R.G. 1.61, but did not evaluate the combined effects of tha use of your spectra and damping values with those resulting from the use of R.G.1.60 and 1.61. Provide the information requested above for our review.

5.108 In request for additional information 5.97 we requested that you state your criteria for floor response spectra broadening '

of the Category I structures located on the soil media. We pointed out that the effect of parameter variation on floor response spectrum for the soil sites are normally accounted 4 for by increasing the individual peak widths by i 15%. You stated that in a previous submittal, you proposed i 10% increase.

However, you did not attempt to justify the adequacy of the proposed criteria in relation with the regulatory staff position ,

i provided in reque t for additional information 5.97. We require that you address the discrepancy between the two criteria and justify the i 10% value proposed. ,

5.109 In request for additional information 5.96 we requested that you provide the criteria used for the selection of the number of the lumped masses for the seismic system analyses. You referred to an answer provided to a staff question raised during the earlier (1974) FSAR review. The answer is found to agree in general to our philosophy. However, it is not specific enough. You should state if you follow the following staff position in the execution of your general philosophy identified in the answer to request for additional information 5.25 or describe and justify any other proposed position. The staff position is:

1

. k .

The number is considered adequate when additional degrees of freedom do not result in more than a a 10% increase in responses. Alternately, the number of degrees of freedom may be taken equal to twice the number of modes with frequencies less than 33 cps.

5.110 In request for additional information 5.100 we asked that you state if the fundamental frequencies of the key subsystems are controlled to be either greater than twice or less than one-half the dominant frequencies of their supporting system. Your response stated that the funda-mental frequencies of the key subsystems were considered in relation to the dominant frequencies of their supporting systems. However, you did not state if the above criteria were used to accomplish the adequate design of the key subsystems or some other criteria that may be proven to be just as adequate. Provide a more detailed response to this concern.

5.111 In request for additional information 5.99 we requested that you identify the method and results of the analysis used in accounting for the torsional effects of Category I structures.

You identified how you have accounted for the torsional effects of Category I structures other than the containment building.

You considered the containment building to be axisynmetric and stated that consideration of a torsional mode is not pertinent. It is our position that a minimum of 5% accidental eccentricity should be considered due to the facts that both construction tolerances and the internal structures would introduce some degree of eccentricity effect. This can be accomplished by evaluating the structure considering a 5%

accidental eccentricity. That is the distance between the actual center of mass and the center of rigidity must be modified by the 5% eccentricity. This modification should consist of an addition of 5% and a subtraction of 5% from the center of mass as shown below, with the controlling case used for design. .

~6Yo +6%

Y fi >

IN O I

Center of Rigidity f - b-. Direction of Excitation p ,

Actual Computed Eccentricity %r

_ Center of Mass _

qAf Provide information to demonstrate the extent to which the containment structure and the components located within the structure are capabic of withstanding the largest load resulting from this criteria.

5.112 In request for additional infurmation 5.105 we requested that you state if you have considered additional load combinations for assessing sliding, overturning and flotation potential of all Category I structures, as recommended by SRP 3.8.5.3. You stated that you have considered these potential phenomena, but did not indicate if you utilized the safety factors indicated in SRP 3.8.5.3.

You should indicate if you use the same safety factors used in SRP 3.8.5.3 for sliding, overturning and flotation forces or justify the ones that you used in the event that they differ from those recommended in SRP 3.8.5.3