ML19351G230
| ML19351G230 | |
| Person / Time | |
|---|---|
| Site: | Midland |
| Issue date: | 02/10/1981 |
| From: | Hood D Office of Nuclear Reactor Regulation |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19351G231 | List: |
| References | |
| ISSUANCES-OL, ISSUANCES-OM, NUDOCS 8102230319 | |
| Download: ML19351G230 (9) | |
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UNITED STATES
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WASHINGTON, D. C. 20555
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FEB 101981 Docket Nos.
Consumers Power Company FACILITY:
itidland Plant, Units 1 and 2
SUBJECT:
SUW1ARY OF APPEALS t1EETING OF AUGUST 29, 1980 REGARDING ADDITIONAL EXPLORATIONS AND TESTING 0F filDLAND PLANT FILL On August 29, 1980. NRC staff management met in Midland, Michigan with Consumers Power Company (the applicant) to hear a request for relief from an NRC staff position requiring additional borings and tests of the plant fill The meeting followed a site tour on Auqust 28, 1980 durino which staff management observed structures and features affected by inadequately compacted backfill used at the site. Attendees at the appeals meeting are listed in Enclosure 1.
Participants in the site tour are listed in Enclosure 2.
The issue of appeal to the Director of Engineering, Mr. R. Vollmer, and the Assistant Director for Components and Structures Engineering, Mr. J. Knight, is whether additional borings and testing of fill soils at the Midland Plant site requested by the NRC staff in a letter of June 30, 1980 are necessary. The staff, supported by its consultant, the U.S. Army Corps of Engineers, contends that the additional borings, testing and resultant geotechnical engineering studies are needed for findings regarding the extent of the soils deficiency and regarding technical adequacy and proper implementation of proposed or completed remedial actions directed to deficiencies in the plant fill.
The applicant, supported by l
several consultants, takes the position that additional borings to justify the adequacy of the remedial action program are unnecessary in that borings, laboratory tests, data collected in connection with the surcharge program for the Diesel Generator Building, and load testing for piles and caissons for other structures provide sufficient information. The applicant also believes that borings should not be taken in the cooling pond dike since this might lead to hydraulic fracturing and slope damage. The applicant also contends that the dike has performed satisfactorily since construction and the borings are unnecessary.
The appeal follows a meeting of July 31, 1980 between the applicant, the NRC Geotechnical Branch, and the U.S. Army Corps of Engineers. No resolution of the differences in view regarding the necd for the additional information resulted l
at this earlier meeting. A letter of August 4,1980 had ado been issued by the staff since the earlier meeting to further describe the staff request of June 30, 1980.
The agenda and sequence of the appeal meeting consisted of (1) introductions by the staff (10 min.), (2) presentations of the applicant's position (1 1/2 hours),
l (3) summary of the. staff position (10 min.), (4) questions by the Director and Assis-l tant Director (15 min.), and (5) the decision (5 min.).
8102230
-2 FEB 10 1981 Applicant's Position and Presentation Viewgraph slides used during the applicant's presentations are shown in Mr. G. Keeley reviewed a chronological sequence for supplying of soils information to the NRC.
Mr. Keeley stated that the response to requests 36 and 38 from the staff's letter of June 30, 1980 would be submitted September 15, 1980 and the response to request 37 during October 1980.
i Mr. J.D. Wanzeck of Bechtel Geotech reviewed the soil investigations performed to date and noted that 199 borings had been submitted to NRC. He also identified test pits, cross-hole shots a :d settlement information which have been described to NRC. Mr. Wanzeck stated that it would be futile to take additional borings in view of the large number cf borings already done. Mr. Wanzeck noted that 66 additional borings had heel taken in the power block area in the previous two months and would be suimitted to the staff in mid-September.
Bechtel consultant, Dr. Ralph Peck, reviewed the technical basis for the applicant's position that the preload program provides an acceptable solution to the unanticipated settlement recorded at the Diesel Generator Building.
He reviewed typical settlements observed during surcharging, piezometer measurements, and predicted settlements extrapolated from the surcharge settlement results which he finds to be reasonably acceptable.
Dr. Peck stated that he could find no reason to believe settlement of the structure in excess of this pessimis-tic prediction will occur.
He felt predictions derived by other means would be erroneous and too large since the state of the artcis limited.
Bechtel consultant, Dr. A.J. Hendron, Jr., discussed errors inherent in settlement predictions derived from consolidation tests from undisturbed samples obtained from borings. He concluded that the need for accuracy requires reliance upon the field approach proposed by the applicant.
Dr. Hendron also described his more recent calculations of bearing capacity which had been revised from earlier calculations.
The new results indicate a factor of safety from bearing capacity failure of about 6 for static loading which meets the normally accepted value of 3.
He concluded that additional borings were unnecessary l
to demonstrate adequate bearing capacity.
Bechtel consultant, Dr. M.T. Davisson, described the use of piles under the Service Water Structure and caissons under the Auxiliary Building.
He stated that piles and caissons eliminate reliance upon fill characteristics. He felt that in place tests under load to be conducted as the underpinnings are installed provides a better technique to establish adequacy of the remedial action.
These presentations by Mr. Wanzeck and by the Bechtel consultants are described in further detail by two documents forwarded by Amendment 81. These are entitled, " Discussion of the Applicant's Position on the Need for Additional Borings", and " Settlement Update".
The applicant's position is also described in Mr. J. Cook's letter of September 16, 1980 to Mr. R.H. Vollmer, i
FEB 101981 Staff Presentation Dr. L. Heller of the NRC Hydrologic and Geotechnical Engineering Branch explained that the purpose of the staff's request for additional borings was to supplement, rather than replace, the field data and prediction technique intended by the applicant. The borings and tests are necessary to better under-stand certain anomalies or questions associated with the applicant's data.
Mr Heller noted that 18 additional borings would seem to be a small addition to the 90u already taken.
He illustrated the staff's need for increased assurance by reference to North Anna settlement projections which were based upon use of field data and which were twice erroneous.
Mr. Joseph Kane, staff geotechnical engineer, described the basis for the request for borings in the cooling pond dike.
The. dike in the vicinity of the emergency pond excavated within the cooling pond must remain stable so as not to jeopardize the emergency water needed for safely shutting down the Midland plant.
The borings are needed to show that the soil materials actually placed in the cooling pond dikes are stable and contain adequate engineering properties It was noted that' the upper phreatic surface for the dike has likely not aad sufficient time to dev21op and further saturation of the dike materials can be anticipated.
The borings lear the Service Water Structure and Auxiliary Building are needed to p rmit testing of undisturbed samples in order to estimate pile and caisson capacity. The field load tests descrioed by Dr. Davisson will also be needed.
However, the staff noted that it is normal engineering practice to analyze pile and caisson capacities based on foundation material properties before installing the piles and caissons in the field.
The additional borings and testing are also needed to establish properties of the plant fill in order to estimate negative.
skin friction and this-additional drag loading on the piles during plant. life.
The borings near the Diesel Generator Building are needed to estimate bearing capa-city and to assure that future settlements will not overstress undergro~und piping. Mr. Kane explained that the pore pressure behavior recorded in piezometers after removal of the sand surcharge leaves some doubt whether secondary consolidation of the fill ha's been achieved. The data requested by the staff should help to eliminate this doubt. Mr. Kane also noted that the fill may have been placed dry of optimum and was not fully saturated under seepage developing from the raised pond before the surcharge load was removed. Mr. Kane-further noted that it is highly unusual to surcharge a completed structure similar to what was performed at Midland. The induced settlements and cracking caused by the surcharge load further complicate the staff's safety evaluation of the involved structure.
At the conclusion of Mr. Kane's presentation, Mr. Davisson noted that the caissons would be installed with friction breakers-(i.e., bentonite slurry) to facilitate penetration through the soil, and therefore, downdrag around the -
caissons should be minimal.
FEB 10.1981 Questions Messrs. Vollmer and Knight asked several questions.
Mr. Vollmer stressed the need for independence and a priori aspects of the staff review, and of the need to avoid overreliance upon technical specifi-cations to monitor settlement in the future if this can be avoided.
He stressed the need for proper assurances to be provided at the front end of the review and construction process. He noted that the staff's requests were intended to provide for expedient resolution of the problems and noted that he was somewhat surprised at Consumer's attitude toward not supplying additional tech-nical information. He inquired of Mr. Cook whether his objection was based upon his perception of staff need or upon a concern that the results niight be misleading or unfavorable and lead to further questioning by the staff. Mr. Cook replied that he feels that the staff's request "would contribute more to confusion than anything else."
Mr. Knight inquired into the basis for the 66 additional borings yet to be furnished to the staff. Mr. Wanzeck replied that they result from studies of groundwater drawdown, seismic cross-hole shots and investigations of the tank farm area requested by the staff. Detailed laboratory tests were not conducted for the samples obtained.
Mr. Vollmer questioned the basis for the applicant's position on additional boriags in the cooling pond dike. Mr. Wanzeck replied that ilttle settlement had occurred to date, that the dike was placed by Canonie using large equipment, that Bechtel's consultants advise against borings with the pond filled, and that it was considered unnecessary because the dike is not needed for any safety purpose. Mr. Vollmer asked about possible obstruction of the emergency pond channel or loss of emergency pond usable volume due to cooling pond dike failure.
Mr. Knight noted the potential significance of the dike to the concrete service water discharge pipes between the dike and the emergency cooling pond. Mr.
Davisson noted that seepage, rather than stability, is the element of interest to dam ailures in general. Mr. Kane commented that borings could be conducted d
in a manner where hydraulic fracturing would not be a concern.
Proper backfilling of the drilled holes would eliminate futuce concerns for uncontrolled seepage through the holes which remained at the completion of the borings.
Decision Following a brief caucus, Mr. Vollmer noted that new information hud been presented during the meeting which would require consideration before a decision is reached. The new information included (1) 66 additional borings which the applicant intended to submit for review, (2) a plot of load versus elevation beneath the Diesel Generator Building, and (3) use of a friction breaker for th e caissones. He also stated that if a der.ision were to be made immediately, he would have to agrea with the NRC staff's aosition that the additional information in the staff's letter of August 4,1980 is needed. Mr._Vollmer stated that the applicant's position regarding the need for borings in the cooling pond dike appear to warrant further thought on his part.
He requested that a
FEB 101981
-5_
summary of the applicant's positions be submitted along with the additional 66 borings by September 15, 1980 and that his decision would be deferred pending review of that further information.
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2' Licensing Branch #3 Division of Licensing
Enclosures:
- 1) Attendees List - 8/29/80
- 2) Tour Participants - 8/28/80
- 3) Viewgraph slides l
l 1
1 1
I l
FEB 10 1981 Mr. J. W. Cook Vice President Consumers Power Company 1945 West Parnall Road Jackson, Michigan 49201 cc: Michael I. Miller, Esq.
Mr. Don van Farowe, Chief Ronald G. Zamarin, Esq.
Division of Radiological Health Alan S. Farnell, Esq.
Department of Public Health Isham, Lincoln & Beale P.O. Box 33035 Suite 4200 Lansing, Michigan 48909 1 First National Plaza Chicago, Illinois 60603 William J. Scanlon, Esq.
James E. Brunner, Esq.
2034 Pauline Boulevard Consumers Power Company Ann Arbor, Michigan 48103 212 West Michigan Avenue Jackson, Michigan 49201 U. S. Nuclear Regulatory Commission Resident Inspectors Office i
Myron M. Cherry, Esq.
Route 7 1 IBM Plaza Midland, Michigan 48640 Chicago, Illinois 60611 4
Ms. Mary Sinclair Ms. Barbara Stamiris 5711 Summerset Drive 5795 N. River Midland, Michigan 48640 Freeland, Michigan 48623 i
i Frank J. Kelley, Esq.
Ms. Sharon K. Warren Attorney General 636 Hillcrest State of Michigan Environmental Midland, Michigan 48640 l
Protection Division 720 Law Building Lansing, Michigan 48913
((
Mr. Wendell Marshall l
Route 10 Midland, Michigan 48640 Mr. Steve Gadler 2120 Carter Avenue St. Paul, Minnesota' 55108 gl
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- Ccmpander, Naval Surf ace Weapons Center cc:
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P. C. Huang G 402 White Oak Silver Scring, Faryland 20910 Mr. L. J. Auge, Manager Facility Design Engineering Energy Technology Engineering Center P. G. Ecx 1449 Canega Park, Califernia 91304 Mr. Villiam Lawhead t!. S. Corps of Engineers i;CEED - T 7tF Flocr a77 t'ichican Avenue Detroit, Michigan 4E22E C'.arles Ec.chhoefer, Esc.
r Atemic Safety & Licensing Scarc U. S. Muclear Regulatory Comrissier Washington, D. C.
20555 Fr. Gustave A. Linenberger I.tcric Safety & Licensing Ecard U. S. Nuclear f.egulatery Cor.cissier Pastington, D. C.
20555 Dr. Frecerick P. Ccuar.
Act. E-125 E'125 N. Verde Trail Pcca Paten, Florida 33433
FEB 10 1981 Attendees Name Organization D. Hood LB3, DL/NRR/NRC A. Schwencer Acting Chief, LB3, DL/NRR/NRC G. Lear Chief, HGEB/DE/NRC R. Vollmer Director, DE, NRC J. Knight A/D, CS-D/NRC J. Cook CPCo, VP-Midland Project G. Keeley CPCo, Proj. Manager-Midland M. Davisson Consultant to Bechtel A. Hendron, Jr.
Consultant to Bechtel J. Wanzeck Geotech R. Peck Consultant to Dechtel S. Afifi Bechtel J. Rutgers Bechtel, Proj. Manager-Midland K. Wiedner Bechtel, Engineer Manager W. Ferris Bechtel, Chief, Soil Engineer T. Thiruvengadam CPCo, Section Head-Civil Engineering J. Brunner CPCo Attorney
- h. Miller Isham, Lincoln & Beale N. Saari CPCo, Public Affairs Director T. Cooke CPCo-Project Superintendent A. Marshall Bechtel, Geotech D. Sibbald CPCo, Sr. Const. Adv.
J. Kates The Saginaw News A. Brodde Mapleton Intervenors R. Landsman NRC, Reg. III, IE G. Gallagher NRC, Reg. III, IE J. Linsley Bay City Times B. Jones NRC/ ELD J. Burroughs Dow Chemical D. Sanks Midland Daily News S. Warren Lone Tree Council & Intervenor-B. Timmons Observer J. Timmons Observer B. Stamiris Intervenor N. Gehrig U.S.-Army Corps of Engineers B. Malamud U.S. Army Corps of Engineers H. Narain Singh U.S. Army Corps of Engineers R. Erickson U.S. Army Corps of Engineers T. Smith
'U.S. Army Corps of Engineers R. Gonzales HGEB/NRR/NRC J. Kane HGEB/NRR/NRC D. Hebert Resident of Midland C. Handler Resident of Midland A.-Wilson Resident of Midland E. Vollmer
.0bserver L. Heller HGEB/NRR/NAL
FEB 10 1581 NRC Tour Participants 8-28-80 Nan:e Organization R. Vollmer DE/NRC A. Schwencer DL/NRC G. Lear HGEB/DE/NRC J. Knight DE/NRC D. Sibbald CPCo Midland T. Cooke CPCo Midland K. Wiedner Bechtel L. Heller HGEB/NRC T. Thiruvengadam CPCo R. Gonzales HGEB/NRC R. Erickson Corps of Engineers J. Wanzeck Bechtel-Geotech T. Smith Corps of Engineers H. Narain Singh Corps of Engineers J. Kane HGEB/NRC D. Budzik CPCo G. Keeley CPCo i
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