ML19242D656

Describes Status,Per Util 790206 Ltr,Expressing Intention to Provide NRC W/Util Positions Which Are Not in Compliance W/Reg Guides.Units Are in Compliance W/Reg Guide 1.138, W/Some Exceptions

ML19242D656
Person / Time
Site:	North Anna
Issue date:	08/13/1979
From:	Brown S VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	Harold Denton, Parr O Office of Nuclear Reactor Regulation
References
RTR-REGGD-01.138, RTR-REGGD-1.138 NUDOCS 7908150673
Download: ML19242D656 (3)

Text

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%'2[DCD .- u >iecrm n.oro.uaa.~.v. m,- ,.o m,,.,i . u August 13, 1979 Pr. Har01d R. Den ton , Director Serial No. 569 Office of Nuclear Reactor Regulation PSE &C /DLP : ma c:wan g Attn: P- O. D. Parr , Ch ie f Light Water Reactors Branch No. 3 Dock et fios . 50-404 Div is ion of Project Managemen t 50-405 U. S. Nuclear Pegulatory Commission Wash in g ton , D. C. 20555

Dear ft Den ton :

Our letter , Serial No. 030 of February 6,1979, ad"ised you of our inten tions to inform you continually of Company pasitions which are not in accordance with individual Regulatory Guidas. This letter adv ises you of the Company position on Regulatory Guide 1.138, Laboratory Investigation of Soils for engineering Analysis and Design of Nuclear Power Plants, Revision 0, dated April 1978, for the North Anna 3 and 4 Units.

Company Fosition fbrth Anna Units 3 and 1 are in compliance with Regulatory Guide 1.128 with the folloaing exceptions and clarifications:

P ar agr aph C. l .c: " Standards traceable of the National Bureau of Standards should be used for recalibration and should be at least four times as accurate as those reouired of the working instrument." Standards that are being used to c alibra te labora tory test equipmen t are more accurate, rather than at least four tires more accurate, than the working ins trument . 'O feel that ce'tain physical prope' ties of soils and rocks are af fected by sampling and by preparation for testing in the l ab oca tory. Therefore, calibrat ing geotechnical laboratory tes t equipmen t to higher standards thaq currently in use would not significantly improve the accuracy of the resul ts.

Paragraph C. l .d: "In general, all soils and rocks sampled at the site should be first idertified and classified using appropriate index and classification tests." Our Engineers' procedug,e is to perform index and classification tests on represenhtive samples to con firm their visual-manual classification. We feel that having to perform index and classification tests on all soil and rock samples would be an unnecessary requiremen t in that both procedures would yield the same conclusion.

Paragraph C.2 : " Moisture seals should be periodically checked and renewed as nended." 'cl hen tube samples are received in the la5, they are inspected for any obv ious leakage. When a tube sample has been selected for testing, the misture seals are inspected in greater detail and the sample b vvp; 1 t$%.4 d'

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w e.ie,t n :e,o a..mcov e m Mr. Harold R. Denton, Director m r r e. 2 is examined for any evidence of drying in the tube. Any evidence of drying is noted on the sample description log and sarples that anpear to have dried are not tested. A periodic inspection and replacement of moisture seals would be time consuming and in our opinion would not provide any better protection than we currently have for testing semples those water content have changed.

Paragraph C.?: "The duration of storage before testing should be recorded for each sample test." The duration of storage is not specifically reported for each test, but can be calculated from the brring logs where the sampling date is given, and the laboratory test data sheets where the date of testing is reported.

Paragraph C.3.a. " Test specimens should be representative of each discrete s3il or rock unit to be tested and should be accurately described on the basis of classification tests to permit establishment of the soil and geologic profiles." Visual-manual techniques are the primary means used by our Engineers in classifying soil and rock samples. Index and classification tests are performed on representative samples to confirm their visual-manual classification. Therefore, we do not feel that it is necessary to perform classification tests on all undisturbed samples of soil or rock.

Paragraph C.3.a.3: "The net length and weight of the sample and the results of other control tests should not have changcd during shipment, storage, and handling of the sample." Our Engineers' procel 'e is to visually inspect undisturbed samples as they are opened and e. truded to determine whether there has been any change in sample length withio the tube or if there are any signs of sample disturbance. The results of these inspections are reported on the sample description log. Also, the laboratory test results are examined for oossible indications of sa' role disturbance. We believe that these two procedares are sufficient to determine hether sample disturbance has o:cu-red.

Paragraph C.3.b: " Scalping nrocedures should be explained together with reasons for expecting results to be valid." A discussion of the validity of test results on scalped materials is not presented ;s part of our Engineers' laboratory test data. However, the laboratory test results indicate which portion of the sample has been scalped. A trained reviewer of the test results would understand the effect of scalping on the results of specific tests.

Paragraph C.4.a.2: "The minimum acceptable B value is considered to be 0.95." Our Engineers have found that for very stiff or hard clays, it may not be possible to achieve a B value of 0.95. However, if the results of such a test were used, the B value would be reported and the probable effect on results of the test could be evaluated by a trained reviewer.

Paragraph C.5.a: "All laboratory test results and soil and rock identifications and descriptions should be documented in detail in a manner that permits independent verification and analysis of data. All test data including seemingly annmalous test results should be included."

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v.o ci .re, m c r e u.a oc .m c c. .- m Mr. Harold R. Denton, Director s" r " w- 3

!!e believe the only way to provide for an independent reviest of all soil and rock .tould be to provide the samples to a reviewer, without testing them. lle feel that the current practice of recording sample descriptions and determining ind3x properties of representative samples is consistent with goo'l engineering practice. Anomalous test data caused by sample disturbance or equipment malfunction are not reported by our Engineers because the data do not reflect the true properties of tha material in the field. Hotever, the records of such tests are maintained as part of their laboratory records.

Appendix 3, Relative Density: "In vibration table testing, both amplitude and frequency should be adjusted to values that yield greatest density."

The frequency of our Engineers' vibratory table cannot be adjusted. We are in com?liance with The Standard Test iiethod for Relative Density of Cohesionless Soils (ASTM D2049) which refers only to an amplitude variable with a fixed frequency of 3600 vibrations per minute.

This position will be placed on file and will be included in the final safety an31ysis report for these units.

We would be pleased to discuss this position with you at your convenience. Should you wish to meet with us to discuss this position, or if you have any questions, please contact us.

-myeh truly yours, ,

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' S n C. Brown, Jr.'

Senior Vice President - Power Station Engin uring a Construction LS1033