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WASHINGTON, D. C. 20555 Q*eiK*f SEP 0 7 1984 MEMORANDUM FOR:
Robert Bosnak, Chief, Mechanical Engineering Branch, DE George Lear, Chief, Structural and Geotechnical Engineering Branch, DE Vincent Noonan, Chief, Equipment Qualifications Branch, DE Boen-Dar Liaw, Chief, Materials Engineering Branch, DE Faust Rosa, Chief, Instrumentation & Control Systems Branch, DSI Walter Butler, Chief, Containment Systems Branch, DSI M. Srinivasan, Chief, Power Systems Branch, DSI Dennis Ziemann, Chief, Procedures & Systems Review Branch, DHFS FROM:
Brian W. Sheron, Chief, Reactor Systems Branch, DSI
SUBJECT:
V0GTLE UNITS 1 & 2 REVIEW OF REACTOR COOLANT SYSTEM HIGH POINT VENTS (TMI ACTION PLAN ITEM II.B.1)
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The applicant in FSAR Section 5.4.15 and in response to Q440.47, has documented the design implementation of the reactor coolant system high point vents.
As-indicated in the Standard Review Plan (SRP) Section 5.4.12, an office-wide review is required of this issue in order to assure acceptability of this design.
NRR branches with review responsibility n e listed in the SRP. Therefore, we request that you review the high point vent system for Vogtle in your branch's area of responsibility as outlined in SRP 5.4.12 and provide the Reactor Systems Branch with the results of your evaluation, if this has not already been done.
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reactor systems aspects of the design have been reviewed and found acceptable.
In order to meet the SER input date to DL, we request you provide your input no later than September 30, 1984.
fth Brian W. Sheron, Chief Reactor Systems Branch Division of Systems Integration cc:
R. Bernero R. W. Houston L. S. Rubenstein J. P. Knight W. V. Johnston M. Miller l
CONTACT:
M. Wigdor, x27592 i
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UNITED STATES k
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,[ '.j WASHINGTON, D.C. 20555 MAY I I M i
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Docket Nos.:
50-424 and 50-425 MEMORANDUM FOR:
Elinor G. Adensam, Chief Licensing Branch No. 4 Division of Licensing FROM:
George Lear, Chief Structural and Geotechnical Engineering Branch Division of Engineering
SUBJECT:
MARCH 1984 SITE VISIT - GE0 TECHNICAL ENGINEERING REVIEW Plant Name: Vogtle Electric Generating Plant, Units 1 and 2 Licensing State: 0L Docket Numbers:
50-424/425 Responsible Branch: LB-4; M. Miller, LPM We are providing Enclosure 1 in order to document the discussions at the March 6 and 7, 1984, site visit and the agreements reached on our request for additional information. provides a list of the attendees at the March site visit.
During the site visit, the geotechnical engineering staff reviewer iden-tified a problem in the Applicant's field procedures for demonstrating fulfillment of a FSAR commitment to control the placement moisture content of Category 1 backfill within specified limits. This problem I
is discussed in greater detail in paragraph 3.d of Enclosure 1.
Until the compaction control test records are provided by the Applicant in response to Q241.4, the extent of the problem caused by using the rapid drying test to establish moisture content of Category 1 backfill material before compaction is not known.
It is our understanding that this infonnation is to be provided to the staff by May 9, 1984.
In the interim, we have recommended that the moisture content of the remaining Category I backfill be controlled as indicated in the following paragraphs.
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J E. Adensam 1.
For Clean Sand Backfill (Soils with less than 5 percent fines of }ow plasticity and/or soils with pemeability higher than 10~ cm/secaftercompaction) j a.
Thoroughly wet (approaching saturation) the clean sand fill -
after it has been spread to the proper lift thickness and'
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immediately follow (within 50 feet) the wetting operation with the compactor. The wetting and compaction operations are to be conducted in such a manner that ponding of free water on the surface of the compacted fill will not be pemitted. This restriction can be met by requiring drainage through proper grading of fill surfaces or the planned placement of fill in recognition of their pemeability characteristics.- Clean sands that have been thoroughly wetted and compacted in this manner will-not be required to meet a specified moisture content range.
In situ density and laboratory
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compaction tests are still required in order to demonstrate the required -level of compaction has been achieved.
2.
For Backfill Other Than Clean Sands (Soils with pemeability l'ess
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than 10 " cm/sec after compaction) a.
After the backfill has been properly placed and spread in a lift, the moisture will be unifomly brought to a condition throughout the entire lift thickness within the required limits of i 2 parcent of optimum moisture content as detemined in ASTM D 1557. As a construction expediency, the rapid drying test (Frying of soil sample on gas burner) would be acceptable as an initial indicator of the moisture condition before compaction, but the final decision on meeting the FSAR moisture content range will be made on fill material tested after compaction in accordance with
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the accepted published procedures of ASTM D 2216 (See Reg. Guide 1.138) and ASlM D 1557.
b.
Any request for deviations by the Applicant from the above specified moisture content controls will require written justification and supporting test data and be subject to the approval of the NRR staff.
The staff's recommendations are prompted by our concern for unanticipated settlements of the fill that could potentially occur if proper moisture controls were not enforced and the fill soils become saturated. We consider the above recommendations to reflect current, good engineering practice in the capaction control of fills and referred the Applicant to the Corps of Engineers Guide Specification for Embankments, CE-1306, for additional infomation and to understand the basis of our recommen-dations.
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E. Adensam The staff's recommendations on moisture control were discussed in telephone conference calls between the Applicant and J. Kane, SGEB and M. Miller, LB-4 on May 2,1984, and on flay 7,1984. The Applicant indicated in these calls that the compaction control test records being forwarded to the NRC will demonstrate their current control procedures are acceptable in obtaining the required degree of compaction.
A tentative date of May 16, 1984, was proposed for a meeting in Bethesda, MD.
to pennit discussions and clarification of any questions that may develop in the staff's review of the submitted data and prior to the staff taking a final position on the moisture content control procedures to be required.
.h AW George L r, Chief Structural and Geotechnical Engineering Branch Division of Engineering Attachments:
As stated cc: w/ attachments R. Vollmer J. Knight T. Novak G. Lear L. Heller M. Miller S. Chan J. Hopkins J. Kane 4
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Vogtle Electric Generating Plant, Units 1 and 2 Docket Nos. 50-424/425 4
Subject:
Summary of Discussions During March 6 and 7, 1984 Site. Visit Prepared by J. Kane, DE, SGEB, GES 1.
The list of attendees who participated in the March 6-7, 1984 visit at the Vogtle site are provided in Enclosure 2.
2.
The site visit afforded the opportunity to the NRC Staff's geotechnical engineering reviewer to view plant construction progress and also permitted the Applicant to discuss the staff's FSAR review questions and request for infonnation which had been forwarded to Georgia Power Company in E.
i Adensam's letter of February 21,1984 to D. Foster.
3.
Each of the 24 questions in the geotechnical engineering area (identified
,as 241.1 through 241.24) were discussed during the site visit with general understandings and agreements being reached on the infonnation and data ---'
that was required to be submit In discussing the review questions,certainclarifyini,tedtotheNRC.
information was obtained for several of the questions. The questions affected by these discussions are addressed in the following paragraphs.
a.
Q241.1 and Q241.20. Because the Radwaste Solidification Building was stated not to be a seismic Category 1 structure, staff questions directed at the drilled caisson foundation design for this structure were withdrawn.
f b.
Q241.2.. Clearly marked half-sized drawings that highlight the _
requested foundation information on seismic Category 1 structures, --
t conduits and piping will be provided by the Applicant in response to this question.
c.
Q241.3. Recoveries of cores from drilling of the clay marl i
foundation materials in the vicinity of important seismic Category 1 I
structures were not available for visual inspection as had been
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requested in the February 21, 1984 letter. The staff's concern for the foundation competency of this lightly cemented rock persists.
The Applicant did agree to search out and and provide the actual field logs of the CS series borings, where poor recovery in 9 out of 36 borings was indicated, in the hope of being able to provide an explanation for the poor recovery (e.g. drilling record indicating).
time consuming grinding of the rock rather than soft or open zones The Applicant was al o requested to provide a list of borings in the J
innediate vicinity of. important seismic Category 1 structures that demonstrate the foundation competency of the clay marl layer with depth.
Field logs will a so be reviewed by the Applicant to establish, l
the extent of slickensides n rock jointing. Available photos--reflecting l
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the condition and competency of the clay marl material are also to be provided. The explanation provided at the site visit as to how e
important soil and foundation parameters were selected in design is to be'ufocumented.
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Q241.4. A few of the voluminous records that summarize the results of compaction control testing of Category 1 backfill-were reviewed by the staff during the site visit. An agreement was reached that in response to Q241.4, only the compaction testing records for the.first six months of 1963 would be required to be tablesandalsothesupportingdatat.h(atincludesgradationand submitted. This information will inc de the control test summary laboratory com action curves. AcopYofBechtel'searchwork specification C2.2, Rev.11, dated February:17,1984) was provided in response to the staff's questions or testing frequency and actions required for test results not meeting specified limits, etc. This specification.needs to be reviewed by the staff when evaluating the compactioncontr4recordstobeprovidedbytheApplicant.
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l A problem was identified by the staff's brief review of.the j
compaction control testing records relative to the Appincant fulfilling a commitment (FSAR, Section 2.5.4.5.2.7) in controllinghhe placement moisture content of Category 1 backfill within + 2 percent of optimum--
mo.isture content. Certain test results in the summary tables provided by the Applicant indicated moisture contents well outside the required
+ 2 9ercent range-(e.g. test no. 8909 for the testing period from T/1/83to4/14/83). When questioned on this matter on March 6, 1984, the Applicant's consultant was unable to provide an explanation on i
the basi.s of information available in the sumary table.
Subsequently on March ~ 7,1984 an explanation wa's given that a rapid drying moisture content test was run in the field when the fill was being placed prior to compaction by rollers and it was the rapid moisture test which was used to decide whether the placement moisture content Ms proper and met specified limits. The staff reviewer indicated that neither the rapid drying moisture test nor the Applicant's practice of using itEto decida on the final correct moisture content range were acceptable for the followhg reasons:
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(1) The rapid drying test is acknokledged to giveiesults that are variable and often questionable and are admittedly'only rough appro5mations.
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(2)'Themoisturecontenttesttobeusedtodecideonmoisture acceptability should be perfonned in the lab.using ASTM D2216.
Normal and good engineering' practice would require the moisture
" test to be performed on the same material removed in the in situ-1 density test because it is the molding moisture condition which exists dyir.s actual compaction that has the most significant influence on resulting soil paraneters (e.g. shear strength and compressibility).
(3) Theoretically, if the moisture content test re$ ult from the rapi'! drying method was correct, there sho61d be little 4
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difference in the test results between the rapid test and the moisture obtained in the in situ density test because specifications on moisture control require the moisture content to be uniformly mixed throughout the entire fill layer within the specified limits.
If differences are shown to exist between the two types of moisture tests, it would be more reasonable to place greater emphasis on the standardized lab test.' The statements made by the Applicant's consultants with-respect to not relying on the moisture content results from the in situ density tests because of potential large changes in in situ moi ture due to rising groundwater levels or to the effects of surfaca precipitation or surface evaporation are not considered realistic in recognition of the procedures, timing and speed in which the field and laboratory tests are normally perfonned.
These factors would be unique site conditions that would have effects at highly infrequent intervals and should actually be y
documented, if in fact they were affecting the test results.
The extent of the problem caused by the practice of using the rapid drying test to check for proper placement moisture contents t
is not known at this time but can be assessed in the future following the submittal of the requested compaction control test records. During the site visit discussions, the Applicant would----
i not agree to the staff's recomendation to control future fill moistture placement using the. lab determined moisture content l
from the in situ density test. The 91scussions ended with the i
staff indicating this issue would, therefore, have to be pursued with higher NRC management.
e.
Q241.5. The Applicant's consultant acknowledged that Table 3
2.5.4-12 ist ht Wror and correctiv.s will be made.
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- f. :Q241.17. Up-to-date plots of settiunent versus time were not available. Several plots with settlement readings up to the fall of 1983 were reviewed and it was indicated that a portion of the Auxiliary Building had experienced a settlement of approximately 3 inches. This amount of settlement is the maximum predicted settlement for the Auxiliary Building which would include the
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years of plant cperation.
In response to Q241.17, the Applicant has agreed to provide tables which sumarize the up-to-date measured settlements fo'r all seismic Category 1 structures but i
only graphical settlement time-history plots for the containment b'ildings, auxiliary building and nuclear service cooling water u
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towers are required to be submitted.
Significant construction activities affecting settlements are to be identified and provided with the submittal of the settlement data, g.
Q241.22.
In response to this question a copy of " Final Report on Dewatering and Repair of Erosion in Category 1 Backfill in Power Block Area, August 15, 1980" was provided for Staff review.
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~,i List of Attendees March 6 and 7, 1984 Site Visit at Vogtle Electric Generating Plant Name Affiliation James Bailey SCS-NSLD Ken Kopecky SCS-NLLD Mehdi Sheibani Georgia Power Co.
Roy Kiser Bechtel Mike Perovich Bechtel Z. Yazdani Bechtel A. Wehrenberg-Bechtel John Hopkins NRC, NRR, DL Joseph Kane NRC, NRR, DE Y