Text

Proposed Findings of Fact & Conclusions of Law on Remedial Soils Issues.Certificate of Svc Encl
	ML20024E343
Person / Time
Site:	Midland
Issue date:	08/05/1983
From:	; CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.)
To:	;
Shared Package
ML20024E337	List: ML20024E336; ML20024E343;
References
	ISSUANCES-OL, ISSUANCES-OM, NUDOCS 8308100264
	Download: ML20024E343 (382)
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UNITED STATES OF AMERICA no Y

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BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of )

) Docket Nos. 50-329-OM CONSUMERS POWER COMPANY ) 50-330-OM

) 50-329-OL (Midland Plant, Units 1 ) 50 -330-OL and 2) )

! APPLICANT'S PROPOSED FINDINGS OF FACT AND CONCLUSIONS OF LAW ON-REMEDIAL SOILS ISSUES 4

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UNITED ~ STATES OF AMERICA NUCLEAR REGULATORY COM!iISSION m

BEFORE THE ATOMIC'SPEETY AND LICENSING BOARD In the Matter of ,

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.. ) Docket Nos. 50-329-OM CONSUMERS POWER. COMPANY ~). 50-330-OM

. (Midland Plant, Units 1

) 50-329-OL

' ) 50-330-OL and~!) )

~. a APPLICANT'S PROPOSED FINDINGS OF FACT AFD', CONCLUSIONS OF LAW

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ON REMEDIAL SOILS ISSUES p- x

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I TABLE OF CONTENTS (by Subject Matter)

Paragraphs

l. Introduction............................ I-X

2. Seismology and Seismic Models........... 1 - 78 A. Introduction ...................... 1-7 B. The Conformance of the Site Specific Response Approach with 10 C.F.R.

Part 100, Appendix A............... 8 - 16 C. The Selection of the Proper Tectonic Province and Appropriate Controllin Earthquake for Midland.............g 17 - 30 D. The Characterization of Ground Motion for Midland................. 31 '58 I. The Use of the Parkfield Records....................... 45 - 54 II. Selection of the 84th Percen-tile As the Representative Spectral Level................ 55 - 58 E. The Development of Dynamic Mathe-matical Models for the Auxiliary Building, SWPS and BWST............ 59 - 76 F. Applicant's Use of 1.5 x FSAR SSE Response Spectra as Substitute For SSRS............................... 77 - 78

3. Diesel Generator Building............... 79 - 209 A. Description of Diesel Generator Building........................... 79 - 85 B. Applicant's Remedial Measures...... 86 - 138 I. Release of Duct Banks......... 91 - 92 II. Surcharge Program............. 93 - 138 C. Evaluation of Seismic Shakedown. . . . . 139 - 142 D. Evaluation of Bearing Capacity o f DGB Footings . . . . . . . . . . . . . . . . . . . . 143 - 146

1 II E. Structural Reanalysis of DGB....... 147 - 180 F. Contentions........................ 180 - 209

4. Auxiliary Building...................... 210 - 244

5. Service Water Pump Structure............ 245 - 269

6. Borated Water Storage Tanks............. 270 - 299

7. Diesel Fuel Oil Tanks................... 300 - 313

8. Underground Piping...................... 314 - 398 A. Introduction....................... 314 - 316 B. Underground Piping Other Than Seismic Category I................. 317 - 323 C. Seismic Category I Underground Piping in General.................. 324 - 336 D. Assurance of Serviceability of -

Buried Seismic Category I Piping... 337 - 382 I. Stress Analysis and Design Criteria...................... 337 - 347

a. Strength Criteria........ 339 - 341

b. Buckling Criteria........ 342 - 344

c. Minimum Rattlespace Criteria................. 345 - 347 II. Service Water Piping.......... 348 - 364

a. Introduction............. 348 - 352

b. Scope of Reinstallation Program.................. 353 - 354

c. Materials Used in the Reinstallation Program... 355 - 357

d. Reinstallation Procedure................ 358 - 362

e. Applicant's ASME Analysis of the Reinstalled Pipe.. 363 - 364 III. Diesel Fuel Piping............ 365 - 367

IV TABLE OF CONTENTS (by Contention)

Paragraphs Stamiris Contention No. 4

4. Consumers Power Company performed and pro-posed remedial actions regarding soils settlement that are inadequate as presented because:

A. Preloading of the diesel generator build-ing

1) does not change the composition of the improper soils to meet the original PSAR specifications; ..... 181 - 184

2) does not preclude an unacceptable degree of further differential '

settlement of diesel generator building........................... 185

3) does not allow proper evaluation of compaction procedures because of unknown 1ccations of cohesion-less soil pockets.................. 186 - 187

4) may adversely affect underlying piping, conduits or nearby struc-tures; and ........................ 188 - 189 341 - 395

5) yields effects not scientifically isolated from the effects of a rise in cooling water and therefore not measured properly; ............ 190 - 191 B. Slope stability of cooling pond dikes is not assured because they were built with the same improper soils and proce-dures (NCR QF172); ..................... 463 - 488 l

i C. Remedial soil settlement actions are not based on adequate evaluation of dynamic responses regarding dewatering effects, differential soils settlement, and seis-mic effects for these structures:

l L

a. Aux. Bldg. Electrical Penetration Areas & Feedwater Isolation Valve l Pits............................... 225 - 234, l

242 l

1

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b. Service Water Intake Building &

Its Retaining Walls................ 259 - 267

c. Borated Water Storage Tanks........ 291 - 299

d. Diesel Fuel Oil Storage Tanks...... 307 - 313

e. DGB................................ 192 - 194

f. Related Underlying Piping &

Conduit............................ 314 - 396 399 - 420 D. Permanent dewatering

1) Would change the water table, soil and seismic characteristics of the dewater site from their originally approved PSAR characteristics -

characteristics on_which the safety and integrity of the plant were based, thereby necessitating a re-evaluation of these characteristics '

for affected Category I structures. 446 - 448 454

2) may cause an unacceptable degree of further settlement in safety related structures due to the anticipated drawdown effect.................... 449 - 451 454

3) to the extent subject to failure or degradation, would allow inade-quate time in which to initiate shutdown, thereby necessitating reassessment of these times........ 452 - 453 454 Therefore, unless all the issues set forth in this contention are adequately resolved, the licensee actions in ques-tion should not be considered an accept-able remediation of soil settlement problems.

o

VI Sinclair Contention No. 24

24. The present site for the Midland facility is not only inappropriate for the reasons set forth in Contention 9, but also affirma-tively unsafe. Serious questions have been raised concerning the ground stability of portions of the site. At least one of the essential buildings of the reactor complex is reported sinking, and construction has been halted on that building. As a result of the serious and unresolved questions con-cerning ground stability, the findings re-quired by 10 C.F.R. SS 50.57(a)(3) and 50.57(a)(6) can not be made.................. 196 - 199 Warren Contention No. 1

1. The composition of the fill soil used to pre-pare the site of the Midland Plant - Units 1 and 2 is not of sufficient quality to assure that preloading techniques have permanently corrected soil settlement problems. The NRC '

has indicated that randem fill dirt was used for backfill. The components of random fill can include loose rock, broken concrete, sand, silt, ashes, etc. all of which cannot be com-pacted through preloading procedures......... 204 - 207, 299 n. 526, 399 n. 671 Warren Contention No. 2

2. A. Because of the known seepage of water from the cooling pond into the fill soils in the power block area, permanent de-watering procedures being proposed by Consumers Power Company are inadequate, particularly in the event of increased water seepage, flooding, failure of pumping systems and power outages. Under these conditions, Consumers cannot pro-vide reasonable assurance that stated maximum levels can be maintained........ 454 n. 768 B. Given the facts alleged in Contention 2.A, and considering also that the Saginaw Valley is built upon centuries of silt deposits, these highly permeable soils which underlie, in part, the diesel generator building and other class I structures may be adversely affected by increased water levels producing lique-faction of these soils. The following will also be affected: ................. 454 n. 768

VII

1) borated water tanks................ 298 n. 535

2) diesel fuel oil tanks.............. 312 n. 556 Warren Contention No. 3

3. Pre-loading procedures undertaken by Consumars Power have induced stresses on the diesel generating building structure and have re-duced the ability of this structure to perform its essential functions under that stress.

Those remedial actions that have been taken have produced uneven settlement and caused inordinate stress on the structure and cir-culating water _ lines, fuel oil lines, and electrical conduit........................... 208 - 209 400 n. 681

-Marshall Contention No. 2

2. Geological conditions that [ sic] the Midland nuclear plant which is causing the plant to settle. [This contention, which presents the same issue as Sinclair Contention No. 24, was accepted by the Licensing Board as it relates to settling of the Midland diesel generator Special Prehearing Conference building only. ~

Order, dated February 23, 1979, at p. 21.]... 200 - 202 i

August 5, 1983 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of )

) Docket Nos. 50-329-OM CONSUMERS POWER COMPANY ) 50-330-OM

) 50-329-OL (Midland Plant, Units 1 )

and 2) 50-330-OL

)

APPLICANT'S PROPOSED FINDINGS OF FACT AND CONCLUSIONS OF LAW ON REMEDIAL SOILS ISSUES I.

This is one of two Partial Initial Decisions in this proceeding. In our Partial Initial Decision on Quality Assur-ance and Management Attitude Issues we describe the history of this hearing in detail.

For present purposes we need only outline the procedural framework.

II.

In July 1978 while monitoring the diesel generator building ("DGB"), which was then under construction, Applicant detected building settlement in excess of that originally anticipated.

This unusual settlement was subsequently attrib-uted to inadequate compaction of plant fill soils on which the DGB is founded. In 1979 Applicant undertook certain remedial measures including a surcharge i program at the DGB and proposed A surcharge or preload is a pressure that is applied to the ground surface for the purpose of stressing the subsoil to some desirable extent. In connection with the DGB the specific purpose of the surcharge was to substantially reduce had been putthat.might settlements take place otherwise after the building into service. Peck, Tr. 3212.

graphs93-138, below. See also para-

i other remedial actions for other safety-related structures and systems founded on and in plant fill. On December 6, 1979, after the DGB surcharge program was completed but before Appli-t cant had begun any further soils remedial work the Staff issued i its " Order Modifying Construction Permits" (" Modification Order").ii III. The Modification order would have suspended all soils-related and remedial work on the Midland Plant, Units 1 and 2 until an application for construction permit amendments authorizing such soils remedial work was submitted and approved by the Staff.

The three grounds enumerated by the Staff as the bases for the Modification Order were " quality assurance defI-ciencies involving the settlement of the diesel generator building and soil activities at the Midland site, the false statement in the FSAR, and the unresolved safety issue concern-ing the adequacy of the remedial action to correct the defi-ciencies in the soil under and around safety-related structures and systecs...." Modification Order at p. 4.

The Modification Order previded that the Applicant or any other person whose interest was affected could request a hearing with respect to all or any part of the Modification Order.

IV.

Applicant filed a timely request for hearing. Under the NRC's Rules of Practice, this stayed the effectiveness of the Modification Order.iIi On March 20, 1980 the NRC appointed the Atomic Safety and Licensing Board and instructed the Licens-1 1

11 as StamirisThe Ex. Modification Order 3, Attachment 15. has been admitted into evidence i' iii See 10 C.F.R. $ 2.204

1 l

ing Board to consider whether the facts set forth in Part II of the Modification Order are correct and whether the Modification Order should be custained. On October 24, 1980 the Licensing Board entered its "Prehearing Conference Order Ruling on Conten-tions and on Consolidation of Proceedings" in which the proceed-ing arising out of the Modification Order (the "OM" proceeding) was consolidated with the pending Operating License proceeding (the "OL" proceeding) . At the present time there are three intervenors in this consolidated OM/OL proceeding, Ms. Barbara Stamiris, Ms. Mary Sinclair, and Mr. Wendell Marshall.iV V. The Licensing Board has determined to address Inter-venors' contentions in two partial initial decisions. Our Partial Initial Decision on Quality Assurance and Management Attitude Issues deals with issues raised in Stamiris Conten-tions 1, 2, and 3.# This Partial Initial Decision on Remedial Soils Issues deals with Stamiris Contention 4 as well as Sin-clair Operating License Contention 24 and Marshall Operating IV A fourth person, Ms. Sharon Warren, was originally admitted as an intervenor in the OM proceeding on September 10, 1980, and on October 24, 1980 three of Ms. Warren's contentions were accepted as matters in controversy in the consolidated OM:OL proceeding. Ms. Warren withdrew as an intervenor effec-tive February 16, 1981.

v Stamiris Contention 1(d), which alleges that Appli-cant's " statements and responses to NRC questions regarding soils settlement issues reflect a less than complete and candid dedication to providing ... adequate acceptance criteria for remedial actions...." was originally not included in Applicant's Proposed Findings of Fact and Conclusions of Law on Quality Assurance and Management Attitude Issues dated October 28, 1981, because it involves technical issues. However, Applicant will address Stamiris Contention 1(d) in the supplemental findings on Quality Assurance and Management Attitude Issues which it expects to file in 1983.

p License Contention 2. We also address Warren Contentions 1, 2 and 3 even though legally Ms. Warren's contentions are no longer matters in controversy in this proceeding.Vi VI. Through a series of stipulations Applicant has agreed not to contest that, as of December 6,1979, the NRC Staff had insufficient information to evaluate the proposed remedial actions for various plant structures and that this constituted an adequate basis for issuance of the Modification Order.Vii Therefore, in determining whether and to what extent the Modifi-cation order should be sustained the parties and the Licensing Board have focused on the current adequacy of Applicant's soils remedial measures rather than on the historical situation as 'of December 6, 1979.

VII. Applicant's remedial actions for DGB had already been carried out pricr to issuance of the Modification Order.Viii l Even though by requesting a hearing Applicant stayed the effec-

! tiveness of the Modification Order, in February 1980 Applicant i

The Licensing Board has not exercised its sua sponte l authority to take up the Warren contentions and thereT6re they are no longer matters in controversy. Texas Utilities Generat-i ing Co. (Comanche Peak Steam Electric Station, Units 1 and 2)

! CLI-81-36, 14 N.R.C. 1111 (1981). However, the parties were l

permitted to file separate findings on the Warren contentions and requested at least to cross-reference findings applicable l

to the Warren contentions in preparing their findings of fact.

I Tr. 9891-9892.

V i

See Joint Exhibits 2 (auxiliary building), 3 (borated water storage tanks and underground piping), 4 (service water l pump structure) and 5 (diesel generator building). Applicant and l the NRC Staff have also entered into stipulations regarding the quality assurance and material false statement issues raised in the Modification Order. See Joint Exhibits 1 and 6, respectively.

viii See generally Keeley, prepared testimony on soils settlement following Tr. 1163.

vcluntarily agreed not to proceed with further soils remedial ac*; ions without NRC Staff review and concurrence. On April 30, 1982 we issued a Memorandum and Order (Imposing Certain Interim Conditions Pending Issuance of Partial Initial Decision),

LBP-82-35, 15 N.R.C. 1060, which required Applicant to obtain explicit prior approval from the NRC Staff (to the extent such approval had not already been obtained) before proceeding with further soils remedial actions. As explained at greater length in LBP-82-35, we found no indication in the record that Appli-cant had failed to honor its commitment; however, we were concerned that there might be certain activities, such as work associated with underground piping, outside the scope of Appli-cant's commitment but within the coverage of the prohibition in the Modification Order. In addition, the Licensing Board had some doubt whether, in the absence of Staff review and approval, Applicant would carry out certain remedial soils activities using appropriate QA procedures and principles. The effect of 1

issuing LBP-82-35 was to sustain, on an interim basis, all of the requirements of the Modification order except the require-ment for submission and approval of amendments to the applica-tions for construction permits, a procedural requirement which was not necessary to attain the safety goals which we believed should be achieved.i*

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LBP-82-35, 15 N.R.C. 1060, 1072. Subsequently in 1982, Ms. Stamiris took what purported to be an appeal of LBP-82-35.

The Appeal Board construed Ms. Stamiris' filing as a complaint against the NRC Staff's compliance with and implementation of the Licensing Board's order, rather than the order itself. The Appeal Board dismissed her purported appeal without prejudice l to her right to present the same arguments to us, in the first i

instance. See ALAB-684, 16 N.R.C. 162 (1982).

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VIII. Pursuant to its February 1980 commitment and subse-quently pursuant to the interim conditions set forth in this Licensing Board's Memorandum and Order, LBP-82-35, Applicant has with NRC Staff concurrence and approval carried out or begun to carry out various soils remedial measures. The work activities authorized since April 30, 1982 by the NRC Staff are catalogued and updated in monthly letters from Applicant's Executive Manager for the soils remedial work, Mr. J. A. Mooney, to Mr. J. J. Harrison, Director of the Midland Project Section, Office of Inspection and Enforcement Region III (USNRC). The most recent of these letters is included in Appendix B to this Partial Initial Decision. The most complex and significant of these actions is the underpinning of the auxiliary building and feedwater isolation valve pits. The NRC Staff concurred with the construction of access shafts and a freezewall in prepara-

tion for this underpinning on November 24, 1981. (Staff Ex. 5, Tr. 5467). More than a year later the NRC Staff began authoriz-ing on a step by step basis the actual underpinning work, starting on December 9, 1982 with the installation and loading of Piers 12E and 12W under the turbine building (Tr.11007).

During the pendency of these hearings the Licensing Board has heard testimony from various witnesses as to how the work is progressing and has from time to time been notified of construc-tion events, including potential items of noncompliance.

l IX. The Licensing Board has taken into account Appli-l cant's performance with respect to ongoing soils remedial work in reaching our Partial Initial Decision on Quality Assurance

and Management Attitude Issues. In addition, in that Partial Initial Decision the Licensing Board has examined the history of Applicant's remedial measures for the limited purpose of determining what light this history sheds on the " management attitude" issues raised by Ms. Stamiris.* However, in this Partial Initial Decision on Remedial Soils Issues we have not allowed the status of plant construction, including the partial completion of soils remedial work, to influence our decision as to whether Applicant's soils remedial measures are adequate to protect the public health and safety. Like other holders of NRC construction permits, the Applicant in this case has pro-ceeded with construction, including remedial soils work, at its own risk. See 10 C.F.R. 5 50.57; Power Reactor Development Corp.

v. International Union of Electrical Workers, 367 U.S. 396, 415 (1961).

X. In this Partial Initial Decision, the Licensing Board concludes that if Applicant's remedial measures can be carried out in accordance with design and quality assurance require-ments, there will be reasonable assurance that the public health and safety will be protected. We address the important question of whether Applicant can carry out the soils remedial i

measures in accordance with design and quality assurance re-quirements in our Partial Initial Decision on Quality Assurance and Management Attitude Issues.

See Applicant's " Proposed Findings of Fact and Conclu-slons of Law for Partial Initial Decision on Quality Assurance and Management Attitude Issues", dated October 28, 1981, at pars. 86-90, 103-106, 109-114, 124-135, 142-190, 201-205, and 217-221. Applicant expects to update these proposed findings in 1983.

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SEISMOLOGY AND SEISMIC MODELS A. INTRODUCTION

1.

i All nuclear power plants, even plants like Midland i

which are not located in seismically active regions, must be designed and built to protect the public from the hazards of radioactive releases should the plant be subjected to movements

_in the earth's crust.1 In 1972, when the construction permits for_ Midland were issued, the AEC approved two postulated earth-quakes for seismic design purposes: an " Operating Basis Earth-quake" with a ground acceleration of 0.06g, and a " Maximum ,

1 Earthquake" or " Design Basis Earthquake" with a ground accelera-tion of 0.12g, where "g" represents the acceleration at the earth's surface due to gravity.2 2.

1 In 1973, 10 C.F.R. Part 100, Appendix A, " Seismic and Geologic Siting Criteria for Nuclear Power Plants" was promul-gated.3 The express purpose of Appendix A is to set forth the 1

Pacific Gas & Electric Co. (Diablo Canyon Nuclear Power Plant, Units 1 & 2), ALAB-644, 13 N.R.C. 903, 909 (1981), quoting i ALAB-519, 9 N.R.C. 42, 45 (1979); Holt, prepared testimony on Mid-land Site. Specific Response Spectra (hereinafter " prepared testi-mony on Midland SSRS") at p. 14, following Tr. 4539; Holt Ex. 10,

p. 8; Kimball, prepared testimony on resolution of an open item i

involving characterization of the Safe Shutdown Earthquake vibra-t tory testimonyground on motion SSE open for item"), the Midland site (hereinafter " prepared at p. 18, following Tr. 4690.

2 See CPCo Application of Reactor Construction Permit and Operating License, Preliminary Safety Analysis Report

("PSAR") Section 2.7.5'(Amendment No. 5, 11/3

(

L Safety Evaluation p. 13 (11/12/70); consumers /69); PowerAEC Staff Company L

(Midland (DecemberPlant, Units 1 and 2) LBP 72-34, 5 A.E.C. 214, 219 14, 1972).

3 38 Fed. Reg. 31,281 (November 13, 1973), as amended at 38 (January 2052 Fed. Reg.10, 32,575 1977). (November 27, 1973 ) and at 42 Fed. Reg.

i

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i principal seismic and geologic considerations which guide the commission in its evaluation of proposed sites for nuclear power plants and the suitability of the plant design bases. Two basic

} decisions are involved in the Appendix A methodology: first, a i

Safe Shutdown Earthquake ("SSE") is selected based on evaluation i

of capable faults, tectonic structures, and tectonic provinces,4

.. and, second, response spectra 5 representing the vibratory ground ;

'l l motion produced by the postulated SSE are constructed.

4 A Safe Shutdown Earthquake or SSE "is the seismic l

event 'which produces the maximum vibratory ground motion for which certain structures, systems, and components are designed to remain functional.'" Pacific Gas & Electric Co., (Diablo Canyon Nuclear Power Plant, Units 1 & 2), ALAB-644, 13 N.R.C:

i 903, 910-911 (1981), quoting 10 C.F.R. Part 100, App. A, IIII

_(c). An Operating Basis Earthquake or OBE is also considered l in designing nuclear plants. 10 C.F.R. Part 100, App. A, 5III (d). An OBE "is the largest earthquake considered likely to i

' occur during a plant's operating lifetime. Nuclear facilities

' must be designed and built to function through the OBE without creating undue risk to the public health and safety." ALAB-644, j 13 N.R.C. at 911. For consideration of plant design "the dis-tinction between the OBE and the more severe SSE is in essence this: the SSE is the seismic design basis for safety-related or-i t

' Category l' structures and equipment and the OBE the benchmark for the balance of the plant." ALAB-644, 13 N.R.C. at 989.

5 10 C.F.R. Part 100, Appendix A, 5 v(a)(1)(iv). Response spectra relate the response of the foundation of the structures to the vibratory ground motion considering such foundations to be single degree of freedom damped oscillators and neglecting soil-structure interaction effects.

on Midland SSRS at p. 4, following Tr.Holt, prepared testimony 4539. The Atomic Safety Licensing Appeal Board has stated that:

. . . a response spectrum is the result of an analytical procedure whereby a number of one-degree-of-freedom harmonic oscilla-tors, each having the same degree of damp-ing but with different natural frequencies, are driven by the time-dependent motion characteristic of a real or postulated seismic event. For a particular event and degree of damping there will be a time-

! (Footnote 5 continued on page 10)

3. In 1978 in connection with the operating license review for Midland, the Applicant proposed an SSE, determined

in accordance with 10 C.F.: R. Part 100, Appendix A, which was consistent with the Design Basis Earthquake approved for Mid-land at the construction permit stage.6 The Applicant stated that the Midland site lies in the Michigan Basin tectonic pro-vince which is part of the Central Stable Region of North l~

(footnote 5 continued from page 9) i dependent response which varies for oscil-lators of the different frequencies. The maximum values of the response of the oscillators in terms of acceleration, velo-

! city and displacement, may be plotted as a -

function of the frequency of the oscil-lators being excited. Such a plot can be

, produced for any one of the three para-meters taken individually. Because of the relationship among acceleration, velocity and displacement under harmonic motion, a tripartite plot showing the maximum re-sponses in acceleration, velocity and '

displacement as a function of oscillator frequency may also be prepared.

4

' Response spectra tend to have jagged peaks and valleys. For engineering analy-sis and design purposes these can be evened i

out either (1) by drawing a smooth curve enveloping the peaks (or by averaging the peaks and valleys), or (2) by statistically combining-individual spectra derived from similar earthquakes. When so smoothed they i are sometimes called " design response

, spectra."

Pacific Gas & Electric Co. (Diablo Canyon Nuclear Power Plant, Units 1 & 2) ALAB-644, 13 N.R.C. 903, 924 n.40 (1981). See i also paragraphs 31-44 and 55-58, infra.

6 l Because this proposed earthquake was submitted to the

?

NRC Staff for their review in Applicant's Final Safety Analysis Report, it is hereinafter referred to as the "FSAR SSE."

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America. By using the Michigan Basin, instead of the entire Central Stable Region, to determine the historical seismicity the Applicant determined the SSE for Midland to be one with a Modified Mercalli Intensity ("MMI") of VI.7 The ground motion which would be produced by the occurrence of the FSAR SSE at the site was characterized by modified Hausner Response Spectra

anchored at 0.12g.8 4.

! During the course of its Operating License review the 4

NRC Staff initially found insufficient support that the Central i 7 intensity orAn earthquake's size is defined either in terms of magnitude. ' Intensity is based on the effects felt as reported by persons witnessing the ear thquake. Modified Mercalli intensity.

Intensity or MMI is the standard scale used to measure Holt Ex. 4.

mental Anrecordings.

earthquake's magnitude is defined on the basis of instru-Thus magnitude is a more accurate measure of earthquake size than intensity, but instrumental recordings are not available for many historical earthquakes. Holt, prepared i

j testimony on Midland SSRS at p. 4 n.1, following Tr. 4539. There

! are several accepted magnitude scales used in different areas of the world, and this caused some confusion in the record. See note 108, infra.

However, unless otherwise indicated in this Partial i

Initial Decision, " magnitude" refers to body wave magnitude, M 8 blg*

The Hausner Response Spectra were modified by increas-l

' ing the 0.2 to 0.6 seconds period response by fifty percent.

" Anchored" refers to the "g" value at the high frequency end of the spectrum:

In an earthquake, a hypothetical very rigid structure (i.e., one with very high natural

. frequencies) would shake in phase with the motion of the ground itself -- and the ground motion would not be amplified in the building. For this reason, the high fre-quency or "zero period" portion of the response spectrum provides a convenient point from which to scale the standard spectrum; hence the high~ frequency end of the spectrum is called the anchor point.

Pacific1 Gas Units & 2),&ALAB-644, Electric Co.

13(Diablo N.R.C. Canyon Nuclear Power Plant, 903, 925 n.43 (1981); see alsoTr.

ing Holt, prepared testimony on Midland SSRS at p. 5, follow-4539.

Stable Region could be subdivided into separate tectonic pro-vinces such as the Michigan Basin. The significance of this position was that it led to the conclusion that a larger earth-quake than.the 0.12g Design Basis Earthquake approved at the construction permit stage was required to represent the seismic hazard at Midland. The Staff's concerns were expressed in a letter dated October 14, 1980 from Robert L. Tedesco, Assistant Director for Licensing, Nuclear Regulatory Commission to J. W.

Cook, Vice President, Consumers Power Company entitled "Seis-mological Input for the Midland Site," along with two alterna-tive proposals for establishing an SSE acceptable to the NRC Staff, based on the assumption that the Central Stable Regiod was the appropriate tectonic province.9 Mr. Tedesco's letter l

informed the Applicant that it was the Staff's position that establishment of acceptable seismological input parameters would be-necessary not only for its Operating License review but also for the Staff's approval of the remedial actions associated with the soil settlement matters.

5.

The Applicant opted to use the second alternative approach of the Tedesco letter and to develop site Specific Response Spectra ("SSRS"). The SSRS submitted by the Applicant Holt Ex. 3. Both of the alternative approaches pro-posed in the Tedesca letter used as a controlling earthquake the 1937 wave magnitude Anna,of Ohio 5.3event M which, the Staff stated, had a body b and a MMI of VII-VIII . The first approachwastousetheggIofVII-VIIIandthestandardized response spectrum of Regulatory Guide 1.60 anchored at 0.19g.

The second approach was to develop Site Specific Response Spectra by collecting representative real time histories for magnitude 5.3 + 0.5 M than 25 kilometers atb b8il earthquakes, sites, represented epicentral distances less centile. at the 84th per-following Tr. Holt,4539. prepared testimony on Midland SSRS at pp. 5-7, '

See also Kennedy, Tr. 6036-6038.

142 Kennedy, prepared testimony on dynamic mathematical models at pp. 12-13, following Tr. 5995; Kennedy, Tr. 6038-6040, 6115-6119.

lumped at the major floor elevations. For the wing areas, the mass associated with each plate element has been lumped in accordance with plate thickness, and the remaining mass asso-ciated with each wing has been lumped at the floor elevations.

The stick (stiffness) elements have been located at the calcu-lated centers of rigidity and are thus horizontally offset from the mass points and each other to account for torsional vibra-tions. The proposed underpinning designs for beneath the control tower and for the wing area have been accounted for, and the mass includes both the concrete and the effective entrapped soil.143

72. For the SWPS the Applicant and its consultant have' submitted a three-dimensional lumped-mass stick model using beam elements. This model was developed in a manner similar to that used for the auxiliary building model. The foundation remedial work consists of placing an underpinning wall beneath

~

the northern portion of the building so as to bring its founda-

tion down to an elevation that is lower than the backfill. The overall dynamic response of the SWPS can be modeled using a single vertical stick. The mass of the structure is lumped at 143 Kennedy, prepared testimony on dynamic mathematical models at pp. 13-17, Figures 2-7, following Tr. 5995; Rinaldi and Matra, prepared testimony on Dynamic and Static Models at pp. 4-5, following Tr. 6129. For both the auxiliary building and the SWPS, the total weight of the entrapped soil is added to the horizontal inertial mass of the walls. Vertically, the walls are free to vibrate relative to the soil, and thus the l

l soil has not been added to the vertical inertial mass. This increase in total weight increases the total shears and moments in the walls, thus increasing the design forces on the walls.

This is based on the conservative assumption that the entrapped soil is moving with the walls. Kennedy, Tr. 6024-6036.

l t

l

[

the major floor elevations.

The water in the SWPS and the soil entrapped within the underpinning walls are accounted for.144 73.

The model which has been submitted for the BWST was developed by Dr. Kennedy and SMA, and it replaces a model which Bechtel had developed.145 The BWST is a vertical cylindrical tank which is supported by the soil beneath the tank and anchored to a ring foundation. The ring foundation must withstand the seismic-induced forces in the tank shell. These forces are nearly totally due to the water in the tank since the tank shell weight is negligible when compared to the weight of the borated water. Therefore, the primary seismic modeling concern is to model properly and conservatively the seismic forces '

induced by the water on the tank shell and thus also on the foundation. Dr. Kennedy testified that it is best to model the impulsive mode, the sloshing mode, and the vertical mode of fluid-structure interaction individually. The seismic forces imposed'upon the tank shell and ring foundation are added by the square-root-sum-of-squares method. The impulsive mode is 144 Kennedy, prepared testimony on dynamic mathematical models at pp. 17-18, Figures 8-12, following Tr. 5995; Rinaldi and Matra, prepared testimony on Dynamic and Static Models at pp. 3-4, following Tr. 6129. See also note 143, supra, in regard to entrapped soil.

145 The foundation of the BWST has been designed based upon the Bechtel dynamic model. The Bechtel model predicts higher loads on the foundation than the Kennedy model by about 20 percent or a factor of 1.2. Because BWST foundation design loads are based upon the higher Bechtel model extra conserva-tism is provided in the remedial work. Dr. Kennedy's model will be used in the Seismic Margin Review and in the checking of the forces on the tank for the SSRS. Kennedy, Tr. 5991-5994, 6006-6008; Rinaldi, Tr. 6279-6280.

---g- ,, p ,y_ y ,. ---. , _ . . - , , , , v ,-.7, ,. . . - - -

modeled by vertical stick elements between mass points distrib-uted up the tank shell. A dynamic model is not required to evaluate the forces in the sloshing and vertical modes. The forces in these two modes can be determined by mathematical equations.146 Dr. Kennedy testified that the foundation ring does not affect seismic modeling except that the rings act as an anchor for vertical movement. Thus, the facts that the old foundation ring is out of plane and is cracked, and that another foundation ring will be added to the BWST foundation as a remedial measure, are irrelevant in the determination of seis-mic response of the BWST.147

74. Dr. Kennedy concluded that the dynamic models for the auxiliary building, SWPS and BWST are adequate for establishing the conservative seismic forces to be used in the design of the remedial work and in the Seismic Margin Review.148

75. In addition to the review of soil spring constants and damping parameters by Dr. Hadala, the NRC Staff's struc-tural reviewer, Mr. Frank Rinaldi, and its consultant Mr. John Matra of the Naval Surface Weapons Laboratory reviewed the 146 Kennedy, prepared testimony on dynamic mathematical models at pp. 19-22, Figures 13-14, Attachment B, following Tr. 5995.

147 Unlike Dr. Kennedy's model, which considers the tank

-to be supported by the soil at the base point of the tank, Bechtel's dynamic model includes the foundation ring. Dr.

Kennedy explained that this is one of the reasons why his model is better and more accurate. Kennedy, Tr. 6044-6052, 6059-6063.

148 Kennedy, prepared testimony on dynamic mathematical models at p. 12, following Tr. 5995.

I i

l other aspects of Applicant's-dynamic models.149 The NRC Staff found that the methodologies used by the Applicant and its consultant to develop and to review the dynamic mathematical models are within the state-of-the<-art.150 The Staff found that the auxiliary building and SWPS models adequately repre-

- sented those structures within the state-of-the-art.151 At the time of the hearings on December 14-15, 1981 the Staff had not been able to review the dynamic model for the BWST.152 Subse-i quently, however, the NRC Staff did perform such a review and Mr. Rinaldi and Mr. Matra testified on February 17, 1982 that the Applicant's dynamic analysis of the BWST was satisfac-tory.153 -

149 Mr. Rinaldi's and Mr. Matra's prepared testimony, following Tr. 6129, swept more broadly than Applicant's in that it also addressed the static (finite element) models for the

auxiliary building, SWPS, and BWST. Because this portion of the Staff's testimony was preliminary in nature and was super-

~

ceded by subsequent NRC Staff' structural testimony with respect

. to the auxiliary building, the SWPS, and the BWST, it is not

discussed further in this Partial Initial Decision.

150 l '

Hadala, Tr. 6131; Rinaldi, Tr. 6131-6134, 6266; Matra, Tr. 6134.

151 i Rinaldi and Matra, prepared testimony on Dynamic and Static Models at pp. 9, 11-14, following Tr. 6129; Rinaldi, Tr.

6258.

152 When the Staff filed its prepared testimony it had not seen Dr. Kennedy's model for the BWST. At the time of the hearings on December 14-15, 1981 the Staff had seen Dr. Kennedy's model but had not reviewed it. Rinaldi, Tr. 6132-6133, 6254-6257, 6263. Cross examination of the Staff witnesses concern-ing the Kennedy BWST model was deferred. Tr. 6257.

153 Rinaldi and Matra, prepared testimony regarding the borated water storage tanks, the emergency diesel fuel oil storage tanks, and electrical duct banks (hereinafter " prepared testimony on BWSTs, etc."), following Tr. 7537.

76. The Licensing Board finds that the methodology used to develop the models for the auxiliary building, SWPS, and BWST was within the state-of-the-art. The Board concludes that these models are adequate for the purpose of defining seismic design forces to be used in the design of foundation remedial work, for conservatively estimating the seismic-induced forces in these structures, and for defining the seismic input to equipment, systems, and components mounted on these structures.

F. APPLICANT'S USE OF 1.5 X FSAR SSE RESPONSE SPECTRA AS SUBSTITUTE FOR SSRS

77. Because no agreement had been reached with the NRC, Staff with respect to the SSRS when the design of the remedial soils measures was begun, the Applicant incorporated what it believed to be a reasonable margin over FSAR seismic criteria into the design.154 Specifically, the Applicant directed Bechtel to use J.5 times the FSAR SSE response spectra in designing the remedial foundation measures for the auxiliary building, SWPS, and BWST.155 Subsequently, Applicant committed ;

that the agreed-upon SSRS would be the design basis for the remedial foundation measures, but it continued to use 1.5 times the FSAR SSE in the actual design work.156 Because the SSRS 154 Affidavit of Thiru Thiruvengadam, dated March 6, 1981, at pp. 6-7, attached to Applicant's Motion to Defer Consideration of Seismic Issues Until the Operating License Proceeding, dated March 18, 1981.

155 Kennedy, Tr. 5996-5997.

156 Kennedy, Tr. 5996-5997.

exceed 1.5 times the FSAR SSE response spectra for some fre-quencies, the Board heard testimony from a number of witnesses as to the adequacy of Applicant's design procedure for the remedial foundation measures.157

78. Applicant has run dynamic analyses of the auxiliary building, SWPS, and BWST using the dynamic mathematical mocels of these structures to confirm the adequacy and conservatism of using design spectra of 1.5 times the FSAR SSE response spec-tra.158 Dr. Kennedy testified that the SSRS responses for the BWST were 1.3 times the FSAR SSE spectra responses. For the SWPS, Bechtel's analyses showed that the SSRS responses were from 1.2 to 1.4 times the FSAR SSE spectra responses. The SSRS responses for the auxiliary building were generally from 1.2 to 1.4 times the FSAR SSE spectra responses.159 However, in the missile shield the SSRS responses were 1.7 times the FSAR SSE 157 i

l The greatest difference between the FSAR SSE response spectra and the SSRS occurs between about S hertz and 15 hertz.

In that range the FSAR SSE accelerations are about double the SSRS. Holt, Tr. 4639-4640.

158 Kennedy, Tr. 5996-6005, 6040-6041.

159 Kennedy, Tr. 6000-6005. For the BWST, this compara-tive analysis was done by SMA using the full range of soil properties described in paragraph 66, supra. Other witnesses, presented by the Applicant in this proceeding to describe the remedial foundation measures for the BWST, have confirmed that using 1.5 times the FSAR SSE is more conservative than using the SSRS. Hanson, Tr. 7278-7280; Boos, Tr. 7949-7951. For the SWPS and auxiliary building the comparative analysis was per-formed by Bechtel using only best estimate soil properties.

Kennedy, Tr. 6003-6004, 6026-6028. Nevertheless, Dr. Kennedy l believed that for these structures the conclusion that 1.5 times the FSAR spectrum leads to larger forces on the founda-tion than would result from the SSRS would still be valid when soil properties are varied. Kennedy, Tr. 6026-6027.

spectra responses. Dr. Kennedy testified that the missile shield has no influence on nor is it influenced by the founda-tion remedial work.160 For each of these structures, the NRC Staff also has subsequently concluded that the use of 1.5 times the FSAR response spectra in designing the remedial foundation measures appears to have been conservative. This will be confirmed by the Staff in the seismic Margin Review of the Midland Plant.101 Accordingly, the Board finds that Appli-cant's use of 1.5 times the FSAR SSE response spectra as a substitute for the SSRS in designing the remedial foundation work is reasonable and conservative.

I l

160 Kennedy, Tr. 6002-6003, 6029-6032.

161 SSER #2, 5 3.7 at p. 3-2. Rinaldi, prepared testi-many on Stamiris Contention 4C(a), (c), (d), (e), and (f) and Warren Contention 3 at pp. 6-8, following Tr. 12080; Rinaldi, Tr. 12130-12131 (auxiliary building). Rinaldi, Tr. 9694-9697, 9713-9718 (SWPS).

I

i DIESEL GENERATOR BUILDING A. DESCRIPTION OF DIESEL GENERATOR BUILDING

79. The DGB houses four diesel generators that provide power to attain a safe shutdown of the Midland plant after a design basis accident and to operate the plant during unfore-seen power outages. The diesel generators and the diesel generator building are classified as Seismic Category I items.

As such, the generators must remain functional and the building must maintain its integrity during certain design basis condi-tions, including postulated earthquakes.162

80. The diesel generator building is located directly '

south of the turbine building. It is a two story, reinforced concrete, box-like structure that is partitioned by reinforced concrete walls into four bays, one for each diesel generator.

The building is 155 feet long, 78 feet, 8 inches wide, and has an overall height of 53 feet, 6 inches. The exterior walls are 30 inches thick, and the interior walls are 18 inches thick.

The building foundations consist of continuous spread footings beneath the interior and exterior walls. These footings are 10 feet wide and 2 feet 6 inches thick. The diesel. generators themselves rest on 6 foot 6 inch thick concrete pedestals which are structurally independent from the rest of the DGB. 63 162 Testimony of Karl Wiedner for the Midland Plant Diesel Generator Building (hereinafter " prepared testimony on DGB") at

p. 1, following Tr. 10790.

163 Wiedner, prepared testimony on DGB at pp. 1, 13, A-1, and Figures DGB-1, DGB-2 and DGB-3, following Tr. 10790; Wiedner, Tr. 10953; SSER #2, 5 3.8.3.4. The thick exterior walls of the structure provide protection against tornado missiles. Wiedner, prepared testimony on DGB at Appendix A, following Tr. 10790.

81. A mud mat, which is a concrete surface from four to more than 12 inches thick, was cast over the entire area of the building before the foundations or pedestals were constructed.164 Beneath the mud mat is approximately 25 feet of plant fill.165 The purpose of the plant, fill was to raise plant grade eleva-

, tion to be above the flood plain of the Tittabawasee River.166

82. Plant fill placed beneath safety-related structures j and utilities at the Midland site consisted mainly of lacustrine and till clays that were excavated from the cooling pond area.

Clean sands (structural backfill) from an offsite source and lean concrete, used as an alternative to the structural back-fill, were also placed as part of the plant fill. The fill -

was placed and compacted above the natural ground surface after removal of organic and topsoil materials.167

83. The natural soils in the main plant area consist of highly variable soil materials and layering conditions that are typical of a glaciated plain. A loose to very dense, brown 164 The purpose of the mud mat was to provide a clean working surface on top of the soil on which forms would be constructed and reinforcement placed for the DGB foundations.

i The mud mat itself is not reinforced and is not a continuous slab. The mud mat has nothing to do with the structural be-havior of the finished structure. Peck, Tr. 3382-3385.

165 SSER #2, f 2.5.4.4.2, p. 2-24.

166 SSER #2, $ 2.5.4.1.1, p. 2-11. The average original ground surface that existed before placement of plant fill was slightly above elevation 600. The DGB foundation elevation is 628. Plant grade is elevation 634. Elevation numbers as used in this Partial Initial Decision refer to feet above mean sea level (National Geodetic Datum). SSER #2, 5 2.5.4.1.1, p. 2-11; Table 2.2, p. 2-12.

167 SSER #2, 9 2.5.4.1.1, p. 2-12; Kane, Tr. 4374.

fine sand is found in some areas of the plant site beneath the thin topsoil layer.168 Underlying the fine sandy soils is a preconsolidated, very stiff to hard, gray, silty clay that con-tains numerous discontinuous silt lenses. This natural founda-tion clay layer is a lacustrine deposit and extends as deep as elevation 545. Glacial till that consists of a very stiff to hard, brownish-gray, silty clay with sand and gravel is located beneath the lacustrine clay layer. The glacial till brownish-gray, silty clay layer is very thick and extends to bottom elevations ranging from 365 to 430 feet. Below the clay till and above the black shale bedrock of the Saginaw Formation lies glacial outwash consisting of predominantly very dense, fine, sand layers with silt, which are occasionally interlayered with very stiff clayey sands, very dense sand and gravels, and very dense silts with gravel. The top of bedrock is encountered at approximately elevation 250 in the main plant area.169 168 SSER #2, 5 2.5.4.1.1, pp. 2-11 to 2-12. See also Hendron, prepared testimony on cooling pond dikes, at pp . 13-14, following Tr. 3940. In Applicant's PSAR there was a commitment to remove naturally occurring loose sand (sand with less than 75% relative density), if any, from beneath the foundations of safety-related structures. On February 24, 1978 the NRC issued an FSAR question concerning this commitment. The documentation available at that time failed to show that all loose sands had been removed. However, based on boring explorations conducted in 1978 and 1979, Applicant and the Staff have concluded that there are no loose sands in the natural soil layers beneath safety related structures. Keeley, prepared testimony on soils settlement at the Midland Site (hereinafter " prepared testimony on soils settlement") at p. 16, following Tr. 1163; Woods, pre-pared testimony on Liquefaction of Saturated Sand During an Earthquake at the Midland Site (hereinafter " prepared. testimony on Liquefaction"), following Tr. 9745; Hood, Kane, Rinaldi and Gallagher, prepared testimony on Contention 2 at p. 22, following Tr. 2530; Kane, Tr. 4364-65, 4381-82. See also Applicant's Findings of Fact on Quality Assurance and Management Attitude Issues, dated October 28, 1981, at paragraphs 206-210.

169 SSER #2, 9 2.5.4.1.1, pp. 2-11 to 2-12.

1

84. Plant fill placement activities took place mainly from 1975 to 1977. The footings for the DGB were poured in October 1977. In July 1978, during routine monitoring of structures for settlement, it was found that settlement of the diesel generator building was in excess of that which would have been expected. Accordingly, on August 21, 1978, a Noncon-formance Report was issued; on August 22, 1978 the NRC Region III Resident Inspector was notified of this potentially report-able condition; and on August 23, 1978 construction on the building was stopped.170

85. As of August 23, 1978, 55 percent of the concrete for the diesel generator building had been placed, with the walls in place to an elevation of 30 feet above grade, the generator pedestals poured, the mud mat poured inside the building, the electrical duct banks placed under the building with horizontal and vertical runs completed, the underground piping in the area under and adjacent to the building installed, and all backfill placed to plant grade level.171 B. APPLICANT'S REMEDIAL MEASURES

86. Shortly after the settlement problem was discovered, Applicant formed a task force of Consumers Power Company and 170 SSER #2, 5 2.5.4.1.1, p. 2-11; 5 2.5.4.4.2, p. 2-24; Keeley, prepared testimony on soils settlement at p. 6, follow-ing Tr. 1163. Applicant filed its first 10 C.F.R. 5 50.55(e) report concerning the DGB on September 29, 1978. Keeley, pre-pared testimony on soils settlement at p. 6, following Tr.

1163.

11 Keeley, prepared testimony on soils settlement at p. 6, following Tr. 1163.

i

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Bechtel employees to resolve the technical issues relating to foundation soils. Expert consultants were retained, including Dr. Ralph B. Peck and Dr. A. J. Hendron Jr. 172 Because Dr.

Peck's and Dr. Hendron's advice played such an important role in Applicant's decisions concerning remedial actions for the DGB, and because these two men later became Applicant's key witnesses defending the adequacy of such remedial actions be-fore this Licensing Board, it is worthwhile at this juncture to describe their qualifications.

87. Dr. Peck graduated from Rensselear Polytechnic Institute in 1934 with the degree of Civil Engineer and in 1937 received the degree of Doctor of Civil Engineering with a major in Struc-tures. He attended the Graduate School of Engineering at Harvard, vigre he studied Soil Mechanics and Foundation Engineering with i

Professor Arthur Casagrande. He worked for over three years on the initial system of Chicago subways, in charge of soil testing and field observations, under the direction of Karl Terzaghi.

l From December 1942 until May 1974 he taught and conducted i

research at the University of Illinois, from which he retired as Professor of Foundation Engineering Emeritus. He is the l author or co-author of 171 technical publications including l

l two standard textbooks: " Soil Mechanics in Engineering Practice" i

and " Foundation Engineering." The.former has been translated t

into over 10 languages; the latter has been used as a text in

[

l over 100 universities in the United States. While a member of 172 Keeley, prepared testimony on soils settlement at pp. 7-8, following Tr. 1163.

the faculty at the University of Illinois, Dr. Peck engaged in consulting work on foundation and other geotechnical projects.

Since his retirement from the University of Illinois he has been engaged on a full-time basis as an individual consultant.

He has been awarded the Outstanding Civilian Service Medal by the Department of the Army.173 In 1974 the President of the United States awarded Dr. Peck the National Medal of Science:

"For his development of the science and art of subsurface engineering, combining the contributions of the sciences of geology andsoilmechanicswitg7ghepracticalart of foundation design."

88. Dr. Hendron is a Professor of Civil Engineering at the University of Illinois. Dr. Hendron holds B.S. and M.S 173 The commendation accompanying Dr. Peck's Outstanding Civilian Service Medal reads:

For noteworthy assistance to the Office, Chief of Engineers as a consultant from July 1954 to December 1972. As an engi-neer, consultant, professor, author, and authority in soil mechanics and foundation engineering, he contributed continuously and outstandingly to the advancement of knowledge and proficiency in the applica-tion of the principles of soil mechanics by the Corps. These efforts, and his sense of ,

public responsibility enabled the Corps of Engineers to design and construct earthworks and pavements with a high degree of safety, economy, and reliability, and to accomplish its Civil Works mission in a more efficient manner.

174 Peck, prepared testimony on the DGB surcharge program (hereinafter " prepared testimony on DGB surcharge") at pp. 1-3 and Attachment 1 (Experience Record), following Tr. 10180. The NRC Staff geotechnical reviewer and the Staff's geotechnical consultant, who on certain issues in this case had differences of professional opinion with Dr. Peck, conceded that he is a "world-renowned expert". Kane, Tr. 4378, Singh, Tr. 11181.

.-. -- - ._. - - - - . - - . ~ - - - _ . . -. . -- -.

degrees in Civil Engineering from the University of Illinois.

In 1963 he received a PhD in Foundation Engineering from the same institution, after studying under Dr. Peck and Professor N. M. Newmark, among others. Dr. Hendron served for two years in the U.S. Army Corps of Engineers as a research engi-neer. Since 1965 he has been employed in teaching and research at the University of Illinois. In additicn he has been retained as a private consultant by various public agencies, consulting engineering firms, utility conpanies, and foreign governments with respect to the design and construction of nuclear power plants, dams, tunnels, and slope stability problems.175

89. To identify subsurface features and foundation condi-tions at the DGB and elsewhere at the Midland site, Applicant initiated a boring exploration and testing program in August 1978 which continued through December 1978. The explorations included 32 borings, 13 Dutch cone soundings, and one test pit in the DGB area. Soil borings were also taken in other plant fill areas.176 The results of these explorations revealed that 175 Hendron, prepared testimony on seismic shakedown settlement of the DGB (hereinafter " prepared testimony on seismic shakedown") at pp. 1-4, following Tr. 8675. Mr. Kane charac-terized Dr. Hendron as a " nationally known" consultant, Tr. 4422..

176 SSER #2, S 2.5.4.4.2, p. 2-24; 5 2.5.4.1.3, p. 2-14; Keeley, prepared testimony on soils settlement at p. 9, following Tr. 1163; Peck, prepared testimony on DGB surcharge at p. 6, fol-lowing Tr. 10180. In 1980, the NRC Staff requested additional explorations in the surcharged plant fill to recover undisturbed soil samples which could be laboratory tested for shear strength and compressibility characteristics. SSER #2, i 2.5.4.4.2, p.

2-24. Applicant, upon the advice of its consultants Dr. Peck and Dr. Hendron initially opposed this request on the grounds (Footnote continued on page 74)

l the fill did not meet specified compaction requirements at all points. The fill was shown to be highly variable and ranged in consistency from very soft to very stiff for the cohesive soils i and from very loose to dense for the granular soils.177

90. In 1978, the plant fill was settling under its own

weight from beneath portions of the DGB. The building also appeared to be tilting slightly to the south. By September 28, 1978 when Dr. Peck first visited the site, the largest measured settlement, located in the southeast corner of the building, had reached about 3 inches. This exceeded the initial 40-year settlement prediction of 2.8 inches.178 j (footnote 176 continued from page 173) l that the additional borings were unnecessary and likely to produce undependable results. See Peck, prepared testimony on DGB surcharge at p. 80, following Tr. 10180; Peck, Tr. 3362-64; Hendron, prepared testimony on bearing capacity of DGB footings '

(hereinafter " prepared testimony on bearing capacity") at pp.

6-8, following Tr. 8586. In 1981 the requested borings were performed and the results provided to the NRC Staff. The NRC Staff has now concluded that the site investigations completed by the Applicant are acceptable and adequate to identify the important subsurface features and foundation conditions at the DGB and elsewhere at the Midland site. SSER #2, 5 2.5.4.1.3,

p. 2-14; Kane, Tr. 8817-8818, 8837-8839.

177 SSER #2, 5 2.5.4.4.2, p. 2-24.

178 Peck, prepared testimony on DGB surcharge at p. 5, following Tr. 10180; Peck Tr. 3220, 10192; Hendron, Tr. 4016-17; SSER #2, 5 2.5.4.4.2, p. 2-24. Measured settlements at differ-ent settlement markers on the DGB for various times in the structure's lifetime are shown in the following Figures: Peck, prepared testimony on DGB surcharge at Text Figure 7, following Tr. 10180; and Wiedner, prepared testimony on DGB at Figure DGB-7, following Tr. 10790. The most up to date and complete information on DGB settlement is found in " Diesel Generator Building Dewatering Settlement Report" dated March 4, 1983, which is an affidavit from Dr. Peck, served on the Board and all parties on April 19, 1983.

a mr. - a~- w m nw <-,---,---------.----.-------,------e - , - - - - - , , - > , . . . - , - . - . - - - na -- a - -

Release of Duct Banks

91. Applicant's investigations showed that one of the reasons why the DGB appeared to be tilting to the south was that four electrical duct banks which penetrate the diesel generator building from below on the northern side of the structure were restraining uniform settlement. The electrical duct banks are rectangular in cross-section, constructed of concrete and a nominal amount of steel reinforcement, and within them are plastic or steel conduits, two to four inches in diameter. The function of the duct banks is to provide a space in the ground through which Seismic Category I cable may be pulled. The four duct banks in question run horizontally south from the auxiliary building beneath the turbine building at about elevation 593, just below the natural ground surface.

l The duct banks then turn upward and enter the DGB through gaps in the building footings. The clearances between the duct

! banks and the footings were not sufficient to allow the build-ing to settle uniformly without becoming " hung up" on the duct banks.179

92. It was determined that the restraint due to the duct 1

banks caused the formation of cracks in the concrete super-179 Wiedner, prepared testimony on DGB at p. 2 and Figures DGB-4 and DGB-5, following Tr. 10790; Shunmugavel, prepared testimony on Seismic Category I Duct Banks (herein-after " duct banks") at pp. 1-2, Figure 1, and Appendix A, l following Tr. 12016; Marguglio, prepared testimony on the

Midland Project Quality Assurance Program, Attachment No. 10, l at pp. 23-14 to 23-16, following Tr. 1501.

1 i

l l

structure of the DGB, most noticeably in the east wall and in the interior partition walls, and to a lesser extent in the north wall. The maximum crack width encountered at this time was .028 inch. These cracks were formed in addition to cracks caused by the normal shrinkage of concrete. In. November 1978, the NRC was notified that, to eliminate duct bank interference with building settlement and to provide positive clearance between the building foundation and the duct banks, the duct banks would be separated from the diesel generator building by increasing the clearances at the building interface. When the duct banks were released, the maximum gap (1-1/2 inches) which existed between certain areas of the building and the soil surfaces partially closed. In addition, a number of the exist-ing concrete cracks decreased in width after duct bank release.

Subsequent building settlement progressed fairly uniformly.180 180 Wiedner, prepared testimony on DGB at pp. 2-3, fol-lowing Tr. 10790. In our Partial Initial Decision on Quality Assurance and Management Attitude Issues, we have dealt with Ms. Stamiris' claim that it would have been better to grout existing gaps under the DGB footings prior to releasing the duct banks, and that failure to do so resulted in additional stresses to the DGB which could have been avoided. For pur-poses of this Partial Initial Decision on Remedial Soils Mea-sures, it is sufficient to note that there is uncertainty whether such grouting would have been beneficial. The decision not to grout likely allowed some immediate stress reduction when the duct banks were released. The NRC Staff was unable to conclude that grcuting would have been a better approach. Dr.

Peck characterized the decision as a " minor consideration" and "never thought it was a serious matter, one way or the other."

Peck, Tr. 3364-3366; Hendron, Tr. 4053-4055, 4103. See also Applicant's Proposed Findings of Fact and Conclusions of Law on Quality Assurance and Management Attitude Issues, dated October 28, 1981, at paragraphs 164-167, and citations contained there-in.

Surcharge Program

93. In December 1978, after careful consideration of alternatives, Applicant, upon the unanimous recommendation of its consultants, decided to " pre-load" or " surcharge" the DGB.

Dr. Peck testified that the purpose of surcharging the area of the diesel generator building was to cause its settlement to occur at an accelerated rate so that under the operating loads of the structure the future settlement would be small and within tolerable limits. Furthermore, the procedure would permit a conservative and reliable estimate of an amount of future settlement that would not be exceeded. Although settle-ment of the building and pedestals would occur during the surcharge period, any measures considered necessary to assure the integrity of the structure and appurtenant facilitics could then be taken with full confidence that future behavior would be acceptable and satisfactory.181

94. At this point it is necessary to discuss briefly some fundamentals of geotechnical science applicable to the surcharge program. Under an added load or stress, a clay deposit or a clay fill decreases in volume and its upper surface settles. A building resting on or in the clay settles accordingly. If the clay is saturated or nearly saturated, the applied stress does 101 Keeley, prepared testimony on soils settlement at p.

8, following Tr.. 1163; Peck, prepared testimony on DGB surcharge at p. 6, following Tr. 10180. See also Peck, Tr. 3212-3215; SSER #2, 5 2.5.4.4.2, p. 2-24; Applicant's Proposed Findings of Fact and Conclusions of Law on Quality Assurance and Management Attitude Issues, dated October 28, 1981, at paragraphs 175-190.

not immediately cause settlement because the water in the voids of the clay is less compressible than the clay structure itself and thus settlement can occur only as water is squeezed out of the pores and escapes from the clay mass. The pressure built up in the water by application of the stress, in excess of the ground-water pressure, is known as the excess pore pressure.

As the excess-pore pressure dissipates by drainage, the clay decreases in volume and its surface settles. Because at least some of the voids in a clay are very small, as are the passages between the voids, the settlement takes place not instantaneously but over the period of time required for dissipation of the ex-cess pore pressure. This phenomenon is known as cons 91idation.182

95. If the voids between the clay particles contain air, or if larger voids between chunks of clay contain air, applica-tion of stress causes an immediate decrease in volume because of the high compressibility of the air. If the air would be unable to escape from a void, the pressure in the air would l increase in accordance with the law of physics, known as Boyle's Law, that states that the pressure in a gas is inversely pro-portional to the volume occupied by the gas. However, clay is also-permeable to air, and consequently the air escapes from the voids when it is under an excess pressure. In a partly saturated soil the stress condition is somewhat complex, be-cause the pore pressure consists partly of pore-air pressure and partly of pore-water pressure, and these two pressures are 182 Peck, prepared testimony on DGB surcharge at pp. 8-9, following Tr. 10180.

not numerically equal. However, the net effect is the same as if the soil were saturated: both air and water escape, and the clay consolidates until there are no excess pressures in either the air or the water. Fundamentally, therefore, there is no difference between the consolidation of a saturated or a partly saturated clay. When an air content is present, part of the settlement will occur almost instantaneously as the air com-presses, and thereafter the settlement will occur mor. slowly.183

96. The mathematical theory of consolidation, also known as the classical theory or the Terzaghi theory, is based on the simplifying assumption that no air is present or that, if air is present, it occurs in the form of bubbles that may be dis-solved in the water. The classical theory of consolidation permits predicting the rate at which settlement of the surface of the clay will occur after application of a load. Specific-ally it predicts a relation between settlement and time that has a characteristic shape when time is plotted to a logarith-mic scale. As time increases the theoretical curves approach a l horizontal tangent, indicating that after a certain amount of time no further settlement will occur.184

97. When laboratory consolidation tests are made, in which samples are subjected to increments of an applied load and the settle.nents are measured, the observed settlement 183 Peck, prepared testimony on DGB surcharge at pp.

9-10, following Tr. 10180.

184 Peck, prepared testimony on DGB surcharge at p. 10 l and Text Figure 1, following Tr. 10180.

curves for all but the smallest load increments agree well with l

the predicted ones throughout most of the settlement range of l

the curves, but after about 70 percent of the consolidation has occurred, the laboratory curves begin to deviate appreciably from the theoretical ones. Whereas the theoretical curves approach a horizontal tangent indicating the completion of consolidation, the laboratory curves approach an inclined tangent indicating that settlement continues at a rate that is constant with the logarithm of time. That is, the settlement-log time curve becomes a straight line. For convenience, the portion of the observed settlement that agrees with the theory is called primary consolidation. The portion in excess of that predicted by theory, including the linear portion, is called secondary consolidation. Secondary consolidation is also regarded as the settlement that occurs after the excess pore pressures have dissipated. Field measurements indicate that stresses from structures or other loads resting above clays produce settlement curves similar to those obtained in the laboratory; that is, field curves also exhibit primary and secondary portions.185

98. In reality, the concept of two completely separable components, primary and secondary consolidation, is only an

. approximation, and the processes leading to both components of i

consolidation are active in different degrees throughout the

! entire time of application of the consolidation stress. Theo-i retical understanding of the relations between primary and i

185 Peck, prepared testimony on DGB surcharge at pp. 10-11, following Tr. 10180.

i yv, .-r,v,-,-. - -,---- - v4---i.v, -,,-*---,w---v -cv-v--.-,r-ve,- -,---,,.,,,r =-i-- - ev v- - - --w -- -'- rwe --+-----+--------=~'<e-7 *- -e-

secondary consolidation has only recently become clarified.

The more refined theory leads to the conclusion, in agreement with laboratory and field experience, that if the primary portion of the compression curve is clearly identifiable, and merges characteristically into the straight-line secondary portion, the straight line so defined will persist and will not, at any advanced time, increase in slope.186 -

99. Surcharging is a well established and widely accepted technique for reducing futt3re settlements of buildings.10 A number of precedents are described in Dr. Peck's testimony.188 Surcharging has been effective above miscellaneous fill, peat, loose sands and silts, organic materials, lake bed clays, clays, clayey silt, sand, compressible clays interspersed with silt lenses, and loose deposits of free-draining materials 186 Peck, prepared testimony on DGB surcharge at pp.

11-13, following Tr. 10180. The linearity of settlement when plotted as a function of the logarithm of time is an observed phenomenon which does not depend on any theory, nor does it depend on the condition that the soil being consolidated is saturated. Peck, prepared testimony on DGB surcharge at p. 11, following Tr. 10180; Peck, Tr. 10289, 10295, 10305.

187 Peck, prepared testimony on DGB surcharge at pp. 13, 16-17, following Tr. 10180.

188 The examples discussed by Dr. Peck are the Veterans Administration complex in Tampa, Florida; the Northwest Miramichi Bridge in New Brunswick, built in 1871-75; the Auditorium Building in Chicago, also built a century ago; and the Concen-trator Building for the Carr Fork Project of the Anaconda Copper Company in Tooele, Utah. Peck, prepared testimony on DGB surcharge at pp. 13-17, following Tr. 10180. The greatest number of surcharging projects have taken place before a build-ing has been started. But there have been a considerable number of precedents, including the Carr Fork Project, where the building has been started before surcharging was undertaken.

There is of course no precedent for the specific combination of circumstances at the Midland DGB. Peck, Tr. 10301-10302, 10441-10442. See also Hendron, Tr. 4105.

consisting of boulders, sand, and silt, with blocks of rock.

The success of the procedure derives fundamentally from the fact that the compressibility of all earth materials is much smaller during a second loading cycle than during the first.

The required duration of the loading is short if the materials to be loaded are free craining, and longer if time is required for pore pressures to dissipate.189 100. The DGB surcharge program as recommended by Dr. Peck and Dr. Hendron included three principal components:

A. To produce, under the weight of the surcharge and the completed portions of the building, stresses at all levels in the subsoil no less than those that will exist and might produce settlement duringfunctionallifetimeofthestructure$@0 B. To maintain these stresses until excess pore pressures had dissipated and thus until primary consolidat surchargehadbeencompleted.jggunderthe C. To maintain constant surcharge conditions thereafter until the linear relation between settlement and the loga-rithm of time was established reliably enough to permit an accurate forecast of future settleme i

were to remain.fh2if the surcharge load I

189 Peck, prepared testimony on DGB surcharge at p. 17, following Tr. 10180. See also the discussion of former Warren Contention 1 in paragraphs 204-207, infra.

190 Peck, prepared testimony on DGB surcharge at p. 6, following Tr. 10180. See paragraphs 102-104, infra.

191 Peck, prepared testimony on DGB surcharge at p. 7, following Tr. 10180. See paragraphs 105-114, 127-138, infra.

192 Peck, prepared testimony on DGB surcharge at p. 7, following Tr. 10180. See paragraphs 115-121, 137, infra.

101. The surcharge consisted of placing a layer of sand about 20 feet high inside and outside the DGB. The height of the surcharge was limited to 20 feet by the practical diffi-culties of filling sand bencath the DGB mezzanine floor. On the north side of the diesel generator building, the lateral extent of the surcharge was limited to approximately 19 feet by the presence of the turbine building. It was necessary to provide a retaining structure that would prevent adverse effects of any lateral loading from the surcharge sand on the turbine building walls. To the west, south and east, space was avail-able to extend the 20 foot high surcharge a minimum of 20 feet beyond the limits of the structure and from that point outward to provide a stable slope for the surcharge without the need for retaining structures. The dimensions of the surcharge were chosen primarily to assure that surcharge stresses beneath the building would not be less than the stresses that might produce settlement under operating conditions after removal of the surcharge. The dimensions of the surcharged area are shown in Dr. Peck's prepared testimony at Text Figure 2.193 102. Preliminary computations demonstrated that ade-( quate surcharge stresses could be obtained with the dimen-sions described above.194 More refined analysis comparing 193 Peck, prepared testimony on DGB surcharge at pp.

27-28 and Text Figure 2, following Tr. 10180; Wiedner, prepared testimony on DGB at Figure DGB-5, following Tr. 10790.

194 Peck, prepared testimony on DGB surcharge at p. 21, following Tr. 10180.

surcharge stresses with operating stresses confirmed this conclusion.195 103. In addition to the sand surcharge, the hold on DGB con-struction voluntarily implemented in August 1978 was lifted in December 1978 because the additional weight of the concrete which would be placed was desirable for surcharge purposes, and because from a structural engineering point of view completion of the structure would increase its rigidity and ability to distribute loads.196 By March 22, 1979, the concrete structure was essen-tially completed; 94 per cent of the structural dead load was in place. Surcharge placement was completed on April 6, 1979.197 104. Dissipation of the excess pore pressures during the surcharge (1) were monitored directly by piezometric observa-195 Peck, prepared testimony on DGB surcharge at pp.

73-77, following Tr. 10180. See also Hendron, Tr. 4106, 4108.

The operating stresses for which the DGB is designed include dead load, live load, and environmental loads such as wind and earthquake. However, consolidation of clay soils leading to settlement is produced only by loads acting over an appreciable period of time. That is, transitory loads such as those due to wind forces and earthquakes do not induce appreciable con-solidation. Some loads classified as live loads are of a long term or permanent nature, such as the weight of equipment in a building. Common engineering practice is to overestimate the live loads in designing structural members. Thus Dr. Peck requested Bechtel to make a careful evaluation to determine realistic long term live loads to be compared with the stresses produced by the surcharge. The realistic value for live loads expected to be present during plant operation turned out to be 25% of the value used in designing structural members. Peck, prepared testimony on DGB surcharge at pp. 74-75, following Tr.

10180; Peck, Tr. 10274-10277; Wiedner, prepared testimony on DGB at p. 19, following Tr. 10790; Hendron, Tr. 8587-8589.

196 Wiedner, prepared testimony on DGB at p. 4, following Tr. 10790; Keeley, prepared testimony on soils settlement at

p. 8, following Tr. 1163.

197 Peck prepared testimony on DGB surcharge at p. 75, following Tr. 10180.

tions in the consolidating subsoil, and indirectly by observing the shape of the curve of settlement plotted with respect to the logarithm of time. Reliability of the settlement pre-diction (2) was assured by waiting for the straight-line trend of the settlement curve to become well defined after due allow-ance for the inevitable scatter in the results of the settlement observations. These conditions, (1) and (2), constituted the acceptance criteria on which Dr. Peck judged the sufficiency of the duration of the surcharge.198 Thus the principal observa-tions to be made during the surcharge were of settlements under the surcharge loading and of excess pore pressures in the subsoil.199 '

105. Settlement observations had already been initiated by optical surveys measuring the elevations of scribe marks on the walls of the building and on the pedestals. In addition, before placement of surcharge, settlement plates were estab-lished on the mud slab or on the ground surface to serve as additional reference points. The movement of the plates were detected by observing the elevations of the tops of rods ex-tending from the settlement plates to elevations above the top 198 Peck, prepared testimony on DGB surcharge at p. 7, following Tr. 10180. Joint Ex. 5, in which Applicant agreed not to contest that as of December 6, 1979 (a date following the removal of the surcharge) the NRC Staff had insufficient information concerning acceptance criteria to be applied (by the NRC Staff) in judging the adequacy of the remedial measures for the DGB, does not constitute an admission by Applicant that the acceptance criteria Dr. Peck used to judge the sufficiency of the surcharge were inadequate. See Tr. 10614-10616. See also Tr. 10902-10904.

199 Peck, prepared testimony on DGB surcharge at p. 19, following Tr. 10180.

of the surcharge fill, where conventional optical surveys could be carried out.200 106. To investigate the variation of compressibility with depth beneath the building, subsurface reference points known as Borros Anchors were selected for installation beneath 12 different areas of the building. The anchors were generally installed in clusters of four, so that settlements within the subsoil would be measured at four different elevations. These installations allowed judging whether the progress of consoli-dation differed at different levels below the foundation.

These anchors were connected to reference rods that could be observed by optical leveling i,n the same manner as the other' settlement reference points. The accuracy of optical leveling, under the circumstances which prevailed in the field, was considered to be on the order of one-eighth inch. Variations of individual observations of this order of magnitude from the trend indicated by the settlement curve for a given reference point were expected, and it was anticipated that the surcharge would need to remain in place until the straight-line secondary portion of the settlement curves could be drawn reliably among the observed points.201 107. As the observations progressed, it was concluded that the precision of the data obtained from reference points on the building could be improved if the settlements were observed not l

200 Peck, prepared testimony on DGB surcharge at p. 20, following Tr. 10180.

201 Peck, prepared testimony on DGB surcharge at pp.

20-21, following Tr. 10180.

only by means of optical leveling, but also by direct measure-ment of the change in vertical distance between building refer-ence points and deep Borros anchors installed in the natural deposit underlying the fill, where settlement due to the sur-charge could be presumed to be negligible. Such improvement in precision permitted a more refined prediction of settlement by extrapolation of the logarithmic time curves. To this end, four additional Borros anchors were installed. The settlement of a reference point on the building was then measured directly with respect to the rod from the anchor by measuring the change in vertical distance with the aid of a dial gage.202 108. For a period of time during the DGB surcharge, settlement-measuring instruments called Sondex devices were also used for the same general purpose as the Borros anchors, that is, for attempting to measure the compression of different layers of the subsoil. The Sondex device consists of a plastic tube which extends down into the ground, around which is a series of metallic rings which are embedded in the soil. A probe is dropped down through the tube and as the probe ap-proaches one of these rings, one can measure an electrical interaction (inductance) between the ring outside the tube and the probe inside. Unfortunately the instrument does not pro-duce a definite indication at the point where the probe passes the ring; instead the electrical current increases as the probe j approaches the ring and decreases as the probe passes the ring 202 Peck, prepared testimony on DGB surcharge at p. 21, l

j following Tr. 10180.

i l

)

and one has to guess where the maximum point occurs. The use of Sondex devices in this application was supplementary to the Borros anchors and experimental in nature.203 Although the instruments were properly installed and read, Dr. Peck testi-fied that they failed to give satisfactory results. Their use was therefore discontinued, and no reliance was placed on them by Applicant or by the NRC Staff in determining the success of the surcharge.204 109. Various types of piezometers are available for measur-ing pore-water pressures. All such piezometers require flow of water into or out of the apparatus in order to permit a measure-ment. The flow requires time and disturbs the equilibrium of the pore pressures around the piezometer tips. The time required for restoration of the equilibrium, and hence for obtaining a correct reading, depends on the type of piezometer and the permeability of the soil in which it is installed. The time lag that may be tolerated depends on the purpose of the instal-lation. The simplest kinds of piezometers are standpipes in which water level is measured by direct sounding. The time lag of such devices may be excessive for some installations, but by appropriate choice of the dimensions of the piezometer tip itself, of the permeable cavity created around the tip during installation, and of the diameter of the riser pipe, the time lag may be reduced to a value small enough for many purposes.

When this can be done, the use of standpipe-type piezometers is 203 Peck, Tr. 3256-3259, 3261-3263; Stamiris Ex. 14.

204 Peck, Tr. 10205. See also Tr. 10209-10210.

L

preferable because the installations are simpler and more dependable.205 110. For the diesel generator building application, 48 piezometers of the standpipe-type were used. Sixteen of the piezometers consisted of porous cylindrical tips connected to plastic-tube standpipes. These piezometers were essentially of the type and dimensions developed by A. Casagrande in the 1940s, specifically to provide a reliable instrument with a time lag appropriate for observation of pore-pressure changes in clay soils under load applications occurring over periods of a few days in contrast to a few minutes or hours. The re-sponse time of the Casagrande-type piezometers at Midland was less than one day.206 111. The remaining piezometers were of the Geonor type.

These are also open standpipes. They differ from the casagrande type principally in that the porous element is a sintered metal cylinder instead of a ceramic tube. As installed at Midland, the reaction time for the Geonor type piezometers was somewhat quicker than for the Casagrande type.207 112. At the time the remedial measures were being consi-dered, the level of the cooling pond water was at about eleva-tion 622, about 5 feet below the maximum anticipated level.

Groundwater levels in the plant fill area were a few feet 205 Peck, prepared testimony on DGB surcharge at pp.

22-23, following Tr. 10180. See also Peck, Tr. 3227-3231.

206 Peck, prepared testimony on DGB surcharge at pp.

23-25, 32, following Tr. 10180.

207 Peck, prepared testimony on DGB surcharge at p. 25, following Tr. 10180.

lower. In order to avoid the complexities in measurement that would be introduced by pore-air pressures if the plant fill were to contain large amounts of air, Dr. Hendron and Dr. Peck concurred in the desirability of allowing the pond level to rise so that the tips of the piezometers and their surrounding capsules of sand would be below groundwater level. The effect of the presence of air would thus be minimized.208 113. If groundwater level beneath the diesel generator building could have been held at a constant high level through-out the surcharge process, constant base conditions for inter-pretation of excess pore pressures would have existed. This would have been an advantage in interpreting the observations of pore pressures. However, it was not possible to raise the pond quickly to a maximum elevation and maintain it at that maximum level, and there was no evidence that, even if this were done, the groundwater levels beneath the diesel generator building would necessarily reach a stable elevation.209 Dr.

Peck testified that not having the cooling pond at a constant maximum elevation during the surcharge did not make the inter-

! pretation of piezometer data impossible or impracticable.210 1

114. The primary objective of surcharging was reached when primary consolidation had been completed at all depths beneath l

208 Peck, prepared testimony on DGB surcharge at p. 26, following Tr. 10180. See also the discussion of Stamiris Contention 4.A.5 in paragraphs 190-191, infra.

209 i Peck, prepared testimony on DGB surcharge at p. 27, following Tr. 10180; prepared testimony on Intervenor's Conten-l tion 2 at pp. 3-4, following Tr. 3211; Peck, Tr. 3233-3234.

210 Peck, Tr. 10197, 3227-3231, 3251-3252. See also

, Kane, Tr. 4415.

l

the structure under the surcharge loading. According to the plots of settlement versus logarithm of time, this occurred at about Day 100 (100 days after the start of the surcharge; Day 1 = January 26, 1979), when the linear portion of the settlement curves was apparently reached for all settlement points. However, the conclusion that the linear portion had been reached could not be drawn until the curve extended as a straight-line far enough beyond Day 100 to assure that the trend was fully established. The trend was well defined by Day 200 by means of the observations on the building reference points, the settlement plates, and the Borros anchors. Further-more, the four deep Borros anchors, observable with a much higher precision, clearly indicated the linear trend by Day 200. In addition, the piezometer observations indicated rapid dissipation of pore pressure; indeed, the dissipation was so rapid that the pore-pressure rise was largely dissipated by drainage during and shortly after the period of surcharge addition. On the basis of these two independent types of evidence, it was clear by about Day 200 that primary consolida-tion had been fully achieved.211 115. A second consideration, however, required that the surcharge remain in place longer than the minimum time for reaching secondary consolidation. By determining reliably the trend of the linear relation between settlement and the logarithm of time, predictions could be made of the future settlement of 211 Peck, prepared testimony on DGB surcharge at pp.

29-30, 34, following Tr. 10180.

the structure at the location of each reference point merely by extrapolating the linear relation to the number of years of service life expected for the facility. This extrapolation would reliably permit prediction of the settlement if the surcharge were never to be removed and if no further loads were to be added to the building. In reality, the surcharge would be removed, resulting in substantial decrease in stresses at all levels, and the load on the building would be somewhat increased, but not to an extent that would compensate for removal of the surcharge. Hence, a prediction of future settle-ment based on the extrapolation procedure would necessarily lead to a conservative, and probably highly conservative, settlement forecast. Since the need to make such a forecast was recognized, the surcharge was left in place until a satis-factory extrapolation could be assured. Dr. Peck and Dr.

Hendron were satisfied that the surcharge removal could begin on August 15, 1979.212 This was approximately 250 days after the beginning of the surcharge on January 26, 1979.213 The NRC l Staff were informed of Applicant's intention to remove the surcharge and did not object.214 Surcharge removal was com-pleted by August 30, 1979.215 I

Peck, prepared testimony on DGB surcharge at pp.

l 30-31, following Tr. 10180.

213 Peck, prepared testimony on DGB surcharge at p. 78 and Appendix C, Figure C20, following Tr. 10180.

214 l Keel'ey, prepared testimony on soils settlement at p.

10, following Tr. 1163.

215 Keeley, prepared testimony on soils settlement at p.

9, following Tr. 1163.

l t

116. Removal of the surcharge was associated with a rise of the settlement reference points extending over a period of two to three weeks, corresponding closely to the period of surcharge removal. The amount of rebound was on the average of about 0.23 inches, and varied for the four deep Borros anchors from 0.19 to 0.26 inch.216 117. The average maximum settlement of the DGB perimeter reference points during the surcharge period was approximately 2.4 inches.217 In general the building tilted somewhat during the surcharge, remaining essentially in-plane, so that settle-ments on the south side of the DGB were greater than on the S

north side. Dr. Peck and Dr. Hendron attributed this to the presence of more sand fill on the north side of the structure than on the south side, rather than to the fact that to the north, the lateral extent of the surcharge was limited to protect the wall of the turbine building.218 The maximum settle-ment during the surcharge period occurred in the southeast corner of the DGB and was approximately 3.2 inches. This resulted in a total settlement of 7.45 inches for the southeast portion of the DGB. 9 216 Peck, prepared testimony on DGB surcharge at p. 43, following Tr. 10180.

217 Peck, prepared testimony on DGB surcharge at Appen-dix C, Figure C19, following Tr. 10180.

218 Peck, Tr. 3282-3283; Hendron, prepared testimony on seismic shakedown at p. 1, following Tr. 8675; Hendron, Tr.

8681. See also Kane, Tr. 8737-8738.

219 SSER #2, S 2.5.4.4.2, p. 2-31.

118. Dr. Peck testified that settlement due to the sand component of the plant fill occurred almost immediately on application of the DGB surcharge. Future settlement of the DGB will take place due to further consolidation of the clay compo-nent. Such settlement will arise from two causes: secondary settlement representing a continuation of the settlement under the dead load of the building and appropriate live loads; and settlement induced by lowering the groundwater level by the permanent dewatering system.220 119. As stated previously, each settlement observation point on the building, including each settlement plate, entered onto a mode of settlement that became linear as a function of the logarithm of time beginning about Day 100 and extending for about 150 additional days until removal of the surcharge. On the assumption that the surcharge was never removed, the trend of the settlement was extrapolated for each point. The date 31 December 1981 was taken as the effective initial date for predicting future significant settlements. By extrapolating on the observed straight-line for each settlement curve to the year 2025, the settlement during the life of the structure after December 31, 1981 was established for each reference point.221 120. The values of future settlement due to secondary consolidation predicted by this procedure at different points 220 Peck, prepared testimony on DGB surcharge at pp.

77-78, following Tr. 10180.

221 Peck, prepared testimony on DGB surcharge at p. 78, following Tr. 10180.

on the perimeter of the DGB range from 0.70 inches to 1.49 inches. Dr. Peck concluded that the upper bound of the static 40-year settlement due to secondary compression is about 1.5 inches for the building, and that an upper bound for the dif-ferential settlement will be about three-quarters of an inch.

The settlements of the pedestals fall within these limits.222 121. The extrapolation procedure described above is based on the assumption that the surcharge was never removed. In reality, of course, the surcharge was removed and some addi-tions were made to the building and pedestal loads. Throughout much of the subsoil, the reduction in stress due to surcharge removal substantially exceeds the stress due to the added loads. At all places there is at least some reduction. Hence, the prediction is conservative. Inasmuch as settlement observa-tions carried out on the structure since removal of the surcharge and addition of the large portion of the final loads indicate a negligible increase in settlement prior to dewatering, the degree of conservatism in the estimate is substantial.

122. The extrapolation procedure described above does not include the effect of dewatering at the Midland site. To eliminate the possibility of liquefaction of any loose sandy zones beneath the DGB, Applicant decided to install a permanent dewatering system to lower the water table to a level beneath 222 Peck, prepared testimony on DGB surcharge at p. 79, following Tr. 10180.

223 Peck prepared testimony on DGB surcharge at p. 79, following Tr. 10180; Peck, Tr. 3217; Hendron, Tr. 4088-4089, 4104.

elevation 610.224 In addition, Applicant has installed a tem-porary dewatering system to enable it to carry out proposed underpinning activities at the auxiliary building and service water pump structure.225 One effect of lowering the water table is to reduce the buoyancy in the upper layers of the soil.

This increases the effective stresses and corresponding strains throughout the mass of soil extending down to the bedrock.

These strains, although very small, when summed over the great thickness of the soil mass can produce a measurable settlement.

When the water table is allowed to rise the stresses in the soil mass decrease and rebound occurs. The response is essen-tially elastic.226 ,

123. Since the removal of the DGB surcharge, dewatering wells have been placed in operation and tested at the Midland site, producing variations in the water table. Starting in about March 1981 the water table was drawn down to approximately elevation 595, which is the elevation Applicant's permanent dewatering system is designed to maintain during plant opera-tion. On February 4, 1982 dewatering was then stopped for a recharge test in which the time for the groundwater levels to reach elevation 610 was measured. On May 6, 1982 dewatering

was restarted and groundwater levels were drawn down about 15 l

224 Peck, prepared testimony on DGB surcharge at p. 76, following Tr. 10180. SSER #2, S 2.4.6.2, p. 2-4. Applicant's liquefaction analyses and permanent dewatering system are discussed in detail in paragraphs 422 et seg, infra.

225 See SSER #2, Appendix I, 55 1.1, 2.2; Peck, Tr.

10466.

226 Peck, Tr. 10461-1063.

.- _. .-. - - _ _ = . .. .-

i-feet lower than any previous level, to approximately elevation i

i 580. This was done in connection with construction activities such as underpinning.227 124. The first drawdown in the water table produced an additional settlement in the DGB of approximately 1/2 inch.

The amount of differential settlement was very small. There was a small rise in the DGB (perhaps one to two tenths of an

{ inch) when the groundwater levels were allowed to rise during the recharge test. The second drawdown produced a total settle-

ment to an elevstion slightly below that which had been seen during the first drawdown, due to the fact that the water table 4

had been lowered further than during the first drawdown.

Future dewatering settlements are expected to be small.228 l 125. The settlements of the DGB due to operation of the perma-nent dewatering system during plant operation have been produced l in advance by the temporary lowering of the water table to eleva-

tion 595, as described in paragraph 123, above.229 These settle-i ments were added by Dr. Peck to the estimate for settlement due to secondary consolidation to arrive at a prediction for total settlement through the year 2025. The predicted total settlement i values are in the range of 1 to 2 inches with a differential of about 3/4 inch. Dr. Peck testified that use of these values in Peck, Tr. 10432-1034; Peck, prepared testimony on DGB surcharge at p. 80 and Text Figure 6, following Tr. 10180. See also " Diesel Generator Building Dewatering Settlement Report" dated March 4, 1983, Figure A. This Report was served by Applicant's counsel on the Licensing Board and all parties on April 19, 1983.

Peck, Tr. 10432-10434. Dr. Peck testified that the variation in groundwater levels due to underpinning activities makes it difficult to preduct exactly the amount of settlement that is likely to occur as a result of construction dewatering.

229 Peck, Tr. 10340, 10342.

structural calculations is conservative.230 These values were in fact used by Applicant in its structural analysis of the DGB, as described in paragraphs 148-152, below.231 126. During the course of their review the NRC Staff and its consultant, the Corps of Engineers, raised a number of questions concerning the effectiveness of the DGB surcharge.

These issues are discussed in paragraphs 127-138, below.

127. Because of several piezometer and settlement readings recorded in the field during the time of surcharging, the NRC Staff had doubts as to whether the surcharge load was main-tained long enough to cause the more compressible plant fill soils to complete primary consolidation and reach secondary '

consolidation. To resolve this concern, the Staff requested additional explorations in the surcharged plant fill to recover undisturbed soil samples of fill that could be laboratory tested for shear strength and compressibility characteristics.

This work was completed in the spring of 1981 and results furnished to the Staff in July 1981.232 The final conclusions reached by the Staff following its evaluation of the laboratory results were that secondary consolidation had not been reached j in all locations prior to surcharge removal.233 However, the l

230 Peck, prepared testimony on DGB surcharge at p. 80 and Text Figure 8, following Tr. 10180.

231 Compare Peck, prepared testimony on DGB surcharge at l Text Figure 8, following Tr. 10180 with Wiedner, prepared testi-

{

mony on DGB at Figure DGB-7 (Line D). There is controversy, how-ever, concerning the way in which these settlement predictions and measured settlement data were used by Applicant as input to its structural analysis. See paragraphs 162-180, infra.

SSER #2, 5 2.5.4.4.2, p. 2-31.

233 Kane, Tr. 10588-10590.

_99_

NRC Staff and its consultant also concluded that the future settlements (time frame of December 31, 1981 to December 31, 2025) estimated by Dr. Peck for use in Applicant's structural analysis of the DGB are sufficiently conservative. The future settlements estimated by Dr. Peck are greater than the settle-ments calculated for the more compressible zones of cohesive fill soils where the Staff believed attainment of 100% primary consolidation had not been achieved.234 Therefore the disagree-ment between the NRC Staff and Dr. Peck and Dr. Hendron whether primary consolidation has been completed at all points beneath the DGB became moot.

128. Mr. Singh testified that his opinion that secondary consolidation had not been reached in some locations was based entirely on the results of the laboratory tests on additional soil borings performed in 1981.235 When asked why secondary l

consolidation had not been reached in all locations beneath the DGB he stated that he did not know, but he offered two possible explanations. First, the heterogeneity of the fill and rigidity i

of the DGB may have resulted in the structure being supported on hard spots in the soil and bridging over soft spots, so that in places the soil may have experienced less than the average

! calculated stress during the surcharge.236 A second possible i

explanation is that there may be certain locations within the fill which have a very low permeability which might not have I

l

234 SSER #2, 5 2.5.4.4.2, Kane, Tr. 10590-19591, 10596-10597; Singh, Tr. 10625-10628, 10666-10667.

235 Singh, Tr. 10674.

1 236 Singh, Tr. 10667-10669.

l l

i

-100-drained out and consolidated during the surcharge period.237 Mr. Kane and Mr. Singh both believed that if the surcharge load had been left in place longer secondary consolidation would even-tually have been reached in all locations.238 Mr. Singh could not estimate the additional time which would have been needed to accomplish this result, since he did not know the thickness of the possible areas of low permeability in the fill.239 129. Dr. Peck disagreed with the NRC Staff that several piezo-meter and settlement readings cast doubt on the effectiveness of the surcharge. He testified that in all field-observation pro-grams, consideration must be given to redundancy of observations and ruggedness of equipment, and allowances must be made for the relatively primitive conditions on construction jobs as compared to scientific laboratories. Measurements must be evaluated cri-tically, and occasional anomalies must be expected, studied, and sometimes discounted in view of the weight of the evidence. Dr.

Peck's prepared testimony contains a thorough review of all the settlement and pore-pressure data. This testimony fully supports his conclusion that the data were adequate, consistent and suit-able on the weight of the evidence for drawing proper conclusions concerning the success of the surcharge programs. The discrepan-cies, errors, and need for adjustment were comparable to those on most well-organized field-observational programs.240 237 Singh, Tr. 10669-10670.

238 Kane, Tr. 10590; Singh, Tr. 10671.

I 239 Singh, Tr. 10671-10674.

240 Peck, prepared testimony on DGB surcharge at pp. 26, 31-68, and Appendices A, C and D, following Tr. 10180; Peck, Tr. 3243-45, 3253-3254.

l

~

-101-130. The data from all of the settlement instrumentation consistently and clearly show the linear relationship between settlement and the logarithm of time between Days 100 and 200.241 There is a need to correct come of the settlement data due to small systematic errors introduced during the transfer of reference points prior to and during the surcharge period.242 However these systematic errors have no influence on the straight line portion of the settlement versus logarithm of time plots on which Dr. PecR based his settlement prediction.243 131. Dr. Peck testified that piezometric observations are prone to anomalies arising from various causes, some of which 241 Peck, prepared testimony on DGB surcharge at pp. 34, 39-40, following Tr. 10180.

242 Peck, prepared testimony on DGB surcharge at pp.

34-38 and Appendix C, following Tr. 10180. The first transfer of reference points occurred about November 24, 1978, when the scriba marks originally installed were replaced by permanent settlement markers. The second change occurred about March 20, 1979, when the presence of the surcharge obstructed the perma-nent settlement points and temporary points had to be estab-lished at a higher elevation in the building. The third change occurred about September 14, 1979 when the surcharge was lower-ed and the permanent settlement markers could again be utilized, except for a few that had been damaged. The plotted settlement curves in some instances show breaks corresponding to September 20, 1979, from which it can be inferred that errors were intro-duced either at the time the higher reference points were established or when the observations were re-initiated on the permanent reference markers. Peck, prepared testimony on DGB surcharge at pp. 34-35, following Tr. 10180; Peck, Tr. 10224-10229.

243 This is because the transfers of reference points did not take place during the period of time during which the slope of the straight line relationship between settlement and the logarithm of time was established. Peck, prepared testimony on DGB surcharge at pp. 37, 41, 67, following Tr. 10180. The reduced accuracy of total measured settlements due to the need to transfer reference points was accounted for in Bechtel's finite element analysis of the DGB by adding a systematic error of .10 inch to the error band assigned to the measured settle-ment data. See paragraph 167 and n.342, infra.

-102-can be identified, whereas others often cannot. Hence, good practice in connection with piezometric observations requires redundancy and consideration of all records.244 Of the 48 piezometers installed in the vicinity of the DGB, eight failed to provide useable records.245 Dr. Peck analyzed the records of the remaining 40 piezometers for two periods, from March to June, 1979, and from June to September, 1979. In each time period, thirty-four readings were very similar, a remarkably high record of consistency.246 The typical piezometer record shows a water level which is rising in a general way from the 244 Peck, prepared testimony on DGB surcharge at p. 43',

following Tr. 10180.

245 Three installed piezometers malfunctioned or were inoperative because they remained dry; three more were damaged by construction activities; the remaining two piezometers had questionable seals and therefore their records were not used.

Peck, prepared testimony on DGB surcharge at p. 33, following Tr. 10180.

246 The period up to June 1979 includes the application of the surcharge load and subsequent settlement for about two months. The period following June includes additional settle-ments under surcharge, the effects of surcharge removal, and the subsequent rebound. The division is convenient because all the piezometric records show fairly stable conditions through-out May and June. Peck, prepared testimony on DGB surcharge at pp. 43-44, following Tr. 10180. During the first period, of the 40 operative piezometers, two gave high readings and four gave relatively low readings. There is no clear explanation for this anomalous behavior. The remaining 34 had quite simi-lar readings. Peck, prepared testimony on DGB surcharge at pp.

i 44-52, 67-68, and Appendix C, following Tr. 10180. During the post-June period only two piezometer records are significantly different from the majority. Two more are slightly different from the ones considered typical. Readings on two more piezo-meters were terminated before surcharge removal. Again, records from 34 piezometers (not the identical set of 34 piezometers I which showed consistent results prior to June, 1979) were remarkably consistent. Peck, prepared testimony on DGB sur-charge at pp. 52-58, 65-67, and Appendix C, following Tr.

10180.

-103-first of the year until about May, after which there is a gradual decrease. This general shape of the curve follows that of the elevation of the cooling pond, which also peaked about the end of May.247 Superimposed on this general shape one can see the effect of the surcharge. Pore pressures increased as the surcharge was added, but did not reach values corresponding to the applied stress because of relatively rapid dissipation.248 This was a result of the relatively high permeability of the clay fill with its sand inclusions. The excess pore pressures at Midland were fully dissipated long before the load was removed. They did not decrease to the original value of ground-water pore pressure, but to the value of pore pressure correk sponding to the groundwater levels that prevailed at the end of the surcharge due to seasonal moisture changes and the opera-tion of the reservoir. On removal of the surcharge, the pore pressures decreased below the groundwater pressures prevailing j at the time. The decrease was small because of the high rate

of dissipation of pore pressures. For the same reason, the f

l negative pore pressures disappeared rapidly, and the piezo-meters quickly began to reflect the groundwater pressures.

247 Peck, prepared testimony on DGB surcharge at p. 44, following Tr. 10180.

248 Dr. Peck found a general correspondence between the placement of surcharge, which was done in stages in various areas, and corresponding episodes of settlement and increased pore pressures. Dr. Peck viewed this result as interesting but not especially significant for purposes of assessing the success l of the surcharge programs. Peck, prepared testimony on DGB j surcharge at pp. 41-43, 44-45, 51-52, following Tr. 10180; l

Peck, Tr. 10230-10239.

l l

,_ . . _ _ __ __ _ ~. . . _ ._

-104-This typical behavior of the piezometers beneath the surcharge area at the DGB conformed completely with expectations based on theory and precedent.249 132. Dr. Peck's testimony also uses the data from the field observations to investigate the coefficient of permeabil-ity of the plant fill, as a means to judge the consistency of all the observations. Dr. Peck's calculations demonstrate that the settlement and pore-pressure data agree on an average coefficient of permeability on the order of 10 -6 cm/sec, a reasonable value for a fill consisting of clay of low plas-ticity with sandy inclusions.250 133. Dr. Peck testified that, in his judgment, the addi-tional borings performed at the request of the NRC Staff in 1981 were likely to produce undependable data.251 Dr. Peck did not place any reliance on the results of these borings.252 In his judgment, there was no data provided by these additional borings which indicated any lack of secondary consolidation, 249 Peck, prepared testimony on DGB surcharge at pp.

51-58, 65-68, following Tr. 10180.

250 Peck, prepared testimony on DGB surcharge at pp.

l

68-70, following Tr. 10180.

251 Peck, prepared testimony on DGB surcharge at p. 80, following Tr. 10180; Peck, Tr. 3362-3364. As originally served on November 15, 1982, Dr. Peck's prepared testimony contained a lengthy explanation of his reasons for believing that the

results of the additional boring and testing program performed l at the request of the NRC Staff in 1981 were undependable.

However, pursuant to an agreement between the NRC Staff and l Applicant, that portion of Dr. Peck's prepared testimony was l

l not offered into evidence and the Licensing Board places no reliance on it. Tr. 10173-10178; Peck, Tr. 10282; Tr. 10352-10357.

252 Peck, Tr. 10282-10284.

-105-notwithstanding the contrary opinion expressed by the Corps of Engineers.253 134. Dr. Peck also addressed Mr. Singh's suggestion that secondary consolidation may not have been achieved in all loca-tions due to pockets of less permeable soil which may have had insufficient time to drain during the surcharge period. Dr. Peck observed that all but one of the piezometers show the same re-sponse (i.e., rapid dissipation of excess pore pressures) during the application of the surcharge load and the ensuing two months.

This means that the pervious sections of these piezometers (which are generally two feet long and located at different elevations within the fill) must have intersected at least one of the more permeable areas (drainage zones) in the fill. This implies that the spacing of such drainage zones must generally be less than 2 feet.254 Dr. Peck showed that the time necessary for a lense of relatively impermeabile clay (coefficient of permeability =

-9 5 x 10 cm/sec) with a thickness of 2 feet to reach consolidation would be about 13 days. Therefore Dr. Peck testified there is no possibility that a time-lag associated with relatively impermeable clay lenses could have invalidated the conclusion he derived 253 Peck, Tr. 10472, 10513.

'254 Peck, prepared testimony on DGB surcharge at pp.

70-71, following Tr. 10180. Mr. Singh apparently would not agree that one can infer the spacing of lenses of relatively impermeable material beneath the DGB based on piezometer responses.

Moreover, although the borings performed in 1981 did provide some information concerning the thickness of the areas which Dr. Singh believed had not reached secondary consolidation, the borings did not provide him with the permeability of these areas. Therefore he was unwilling to accept the argument made by Dr. Peck and described in the text above. Singh, Tr. 10671-10674.

-106-from the piezometers, or that residual excess pore pressures existed during the 100 or more days in which the settlement log-time curve was linear.255 135. Dr. Peck also addressed the question of whether softer and harder spots within the nonhomogenous plant fill could have had an influence on the effectiveness of the sur-charge. Among the hard inclusions are conduits, duct banks, backfill concrete, and possibly local zones of unusually stiff soil. Stiff or hard inclusions being less compressible than the surrounding materials attract stress and cause a reduction of stress due to surcharge in softer surrounding areas. However, because of the increase in attracted stress, the compression of the soils above and below the hard inclusion, or if the inclu-sion is soil, within the inclusion itself, is greater than average and the settlement of the overlying ground surface is only slightly affected by the presence of the hard spot.

Furthermore, after removal of the surcharge, the highly com-pressed zones remain stiffer than the surrounding areas and will continue to attract any increase in stresses due to in-creases in the loading from the structure. Because the at-tracted stresses act on the stiffened material, the increase in settlement is small. The softer zones that may exist nearby, which did not originally attract their share of consolidation l

stress, continue to remain softer and do not attract the addi-l tional stresses from applied loads to the same extent as the 55 Peck,. prepared testimony on DGB surcharge at pp. 70-71, following Tr. 10180.

-107-hard spots. Therefore the soft spots do not constitute sources of additional unusual settlement. Thus, the application of a surcharge on a heterogeneous fill containing soft and hard portions has a tendency to homogenize the stress-strain behavior of the entire mass. Remaining soft spots do not attract suffi-cient stress to be the seats of disproportionate settlement.256 136. Similarly, the rigidity of the walls and foundation of the diesel generator building itself, which alters the otherwise uniform loading that would be transmitted to the soil by the level portion of the surcharge, has a negligible effect on the uniformity of stress distribution within the subsurface materials. Where the settlement of the building exceeds that which would occur under a uniform load, stresses at shallow depth in the subsoil are increased and the compressibility of the materials is decreased. Conversely, where the rigidity of the structure reduces the contact pressure, the settlement is less than would be the case under a uniform load and the com-pressibility of the soil remains somewhat greater. When the surcharge has been removed and new loads are applied through the structure, the deformation characteristics of the structure still redistribute the load in the same fashion, the softer i

portions of the subsoil at shallow depth remain relatively less stressed, and therefore do not experience a disproportionate increase in settlement. Hence, surcharging the subsoil by i loading a structure of appreciable stiffness also homogenizes l the behavior of the subsoil with respect to settlement when the 6

Peck, prepared testimony on DGB surcharge at pp. 71-72, following Tr. 10180; Peck, Tr. 10272-10273.

-108-surcharge is removed and new loads are added to the struc-ture.257 137. During cross-examination of Dr. Peck on December 7, 1982 the NRC Staff asked him a question about the slope of the settlement versus time curve for one of the diesel generator building settlement markers. Although the curve was difficult to interpret, the slope of the curve for a period of time after about 1000 days after the beginning of the surcharge program appeared to exceed the average slope for the perimeter markers on the DGB between Days 100 and 200, when the surcharge was still active. This observation led to the further question whether settlement predictions based on linear extrapolation of the straight line portion during surcharging would be conserva-tive. Dr. Peck's tentative conclusion at that time, which was subsequently confirmed by a detailed analysis submitted in the form of an affidavit, was that the increased settlement was due to compression of the natural soil underlying the plant fill caused by plant area dewatering activities. Thus the apparent increase does not invalidate the extrapolation procedure for predicting future settlement in the plant fill. Moreover, future settlement of the underlying natural soil will be negli-gible because future groundwater lowerings will not be appre-ciably greater than those already achieved.258 257 Peck, prepared testimony on DGB surcharge at pp. 72-73, following Tr. 10180; Peck, Tr. 10272-10273.

258 Peck, Tr. 10404-10417, 10428-31044; Staff Ex. 16;

" Diesel Generator Building Dewatering Settlement Report" dated March 4, 1983 (which includes an affidavit from Dr. Peck dated March 4, 1983), served on the Licensing Board and all parties by Applicant's counsel on April 19, 1983. See also Kane, Tr. 10569.

-109-138. This Licensing Board agrees with Dr. Peck's and Dr.

Hendron's conclusion that secondary consolidation was reached in all locations beneath the DGB prior to surcharge removal.

This conclusion is not crucial to our decision, however, since even if we accepted the NRC Staff's view that there may be locations in which secondary consolidation was not reached, this would not lead to any increase in DGB settlement predic-tions for the 40-year life of the plant.259 The Licensing Board finds that the predicted settlement proposed by Dr. Peck and approved by the NRC Staff are conservative and appropriate values to use in assessing the structural adequacy of the 60 DGB. The Technical Specifications for the Midland Plant will include a long term settlement monitoring program which will ensure that these settlement values are not exceeded during the lifetime of the plant.261 C. EVALUATION OF SEISMIC SHAKEDOWN POTENTIAL 139. Dr. Peck's estimate of future settlement for the DGB is for static settlements. It is well recognized that consolida-tion of clay soils leading to settlement is produced only by loads acting over an appreciable period of time. That is, 1

259 Peck, prepared testimony on Stamiris Contention 2 at

p. 4, following Tr. 3211; Peck, Tr. 3237; Peck, prepared testi-mony on DGB surcharge at p. 81, following Tr. 10180; Hendron,

! Tr. 4105; SSER #2, 5 2.5.4.4.2, p. 2-31.

1 260 These predicted settlements are shown in Dr. Peck's prepared testimony on DGB surcharge at Text Figure 8, following Tr. 10180.

261 SSER #2, 6 2.5.4.6.3; Peck, prepared testimony on l DGB surcharge at p. 81, following Tr. 10180.

-110-transitory loads such as those produced by earthquakes do not induce appreciable consolidation of clay soils.262 However, during an earthquake sandy soils can undergo some permanent 4

vertical strain due to the cyclic shear strains produced by earthquake ground motion. The magnitude of this vertical

" shakedown" settlement is a function of the thickness of the sand layers, the relative density of the sands, and the magnitude of the cyclic shear strains produced by the earth-quake.263 140. Dr. Hendron evaluated the seismic shakedown settle-ment of the DGB for an intensity of motion which would corre-spond to an upper bound ground surface acceleration 0.19g.

Dr. Hendron concluded that the north side of the DGB will settle about .25 inch + .15 inch under an earthquake accelera-tion of 0.19g and the south side will settle about .05 inch +

.05 inch. The north side of the building will settle more during the earthquake because there is a larger thickness of sand under the north side of the DGB. The building will tend to rotate slightly toward the north during seismic shaking just as it has tended to rotate south during static settlement due to the higher percentage of clay under the south side of the 62 Peck, prepared testimony on DGB surcharge at pp. 74, 79, following Tr. 10180. Dr. Peck also testified that the occurrence of an earthquake will not produce a rejuvenation of clay settlement. Tr. 10332.

263 Hendron, prepared testimony on seismic shakedown at

p. 4, following Tr. 8675.

t l

-111-building.264 In Dr. Hendron's opinion this seismic shakedown settlement would not affect the safety of the DGB. This opinion was subsequently confirmed by Applicant's structural engineering witness, Mr. Wiedner.266 It should be noted that the surcharge did not have any effect on the magnitude of the expected seismic shakedown since it did not appreciably increase the density of the sand under the DGB. 67 141. When the diesel generators are placed in operation they will produce vibrations which may result in some shakedown settlement of sands beneath the DGB. Even though the shear stresses produced by the diesel generators will be more than an order of magnitude less than the earthquake shear stresses, -

there will be a larger number of cycles than during an earth-quake. Dr. Hendron did not have data available at low enough stress levels to estimate the magnitude of this potential shakedown effect. However, any shakedown caused by operation of the diesel generators would increase the relative density of 264 Hendron, prepared testimony on seismic shakedown at pp. 1, 8, following Tr. 8675. The procedure for calculating the magnitude of seismic shakedown is relatively new. It has been used to produce results in agreement with observed shake-down settlement in one instance, the Jensen Filtration Plant in California. The soil conditions at the Jensen Filtration Plant i were more susceptible to seismic shakedown than they are at the .

Midland DGB; that is, there is a greater depth of cohesionless material beneath the Jensen Filtration Plant. Hendron, Tr.

8693-8696, 8698-8699; Kane, Tr. 8840.

265 Hendron, Tr. 8696-8697.

266 Wiedner, prepared testimony on DGB at pp. 18-19, following Tr. 10790.

267 Hendron, Tr. 8699; Kane, Tr. 8799-8800.

-112-the sands and thus reduce potential seismic shakedown settle-ments.200 Applicant has agreed to monitor the settlement of the diesel generator pedestals before and after the first operation of the diesel generators.269 142. The NRC checked the seismically induced settlement values estimated by Applicant and concluded that these settle-ments are acceptable.270 Mr. Kane testified that another of Applicant's consultants, Dr. Richard Woods, had calculated that settlements due to vibration from operation of the diesel generators would be very small, much smaller than that due to seismic shakedown. Nevertheless Mr. Kane stated that he thought it would be advantageous to monitor settlement of the diesel-generator pedestals before and after the first operation of the diesel generators. The Staff intends to review Applicant's proposed monitoring plan.271 D. EVALUA1 ION OF BEARING CAPACITY OF DBG FOOTINGS 143. Dr. Hendron also testified on behalf of Applicant concerning the bearing capacity (ultimate load carrying capacity) of the footings of the diesel generator building. As stated previously, the DGB is founded on a 10 foot wide continuous 268 Hendron, Tr. 8685-8688. .

69

} Tr. 10002-10003.

270 SSER #2, S 2.5.4.5.6.

'. 271 Kane, Tr. 8739-8742.

4 s

0 0

1

-113-wall footing around the perimeter of the structure; in addition three north-south wall footings, also 10 feet wide, support the interior walls which separate the four bays of the DGB. If the supporting coil lacked adequate bearing capacity, the DGB footings could experience very large deformations as the ground would slide out from beneath them. The onset of bearing capa-city failure would be evidenced by the DGB footings beginning 3

to punch into the ground. Bearing capacity relates to factors of safety against the total failure of the footing; it does not relate to primary or secondary settlement of the structure.274 144. The factor of safety against bearing capacity failure 275 is defined as the ratio of the net ultimate bearing capacity over the net applied pressure at the base of the footing.276 Determination of the net applied pressure at the ba e of the footing requires consideration of loads from the str cture, 272 Hendron, prepared testimony on bearing capacity at p.

5 and Figures 2 and 3, following Tr. 8586.

273 Hendron, prepared testimony on bearing capacity at Figures 4 and 5, following Tr. 8586; Hendron, Tr. 8590-8591, 8608. The onset of bearing capacity failure would not neces-sarily mean structural failure for a very rigid structure such as the DGB. The building could rotate as a rigid body under such conditions. Hendron, Tr. 8608.

274 Hendron, Tr. 8590-8591.

275 The " net ultimate bearing capacity" is the pressure that can be supported at the base of the footing in excess of the pressure at the same level due to the weight of the soil above the footing. Hendron, prepared testimony on bearing capacity at p. 9, following Tr. 8586; Applicant's Ex. 26.

276 Hendron, prepared testimony on bearing capacity at

p. 10, following Tr. 8586.

-114-which are supplied by structural engineers.277 Standard prac-tice in foundation engineering for many years has been to require a factor of a safety of 3.0 when long term static loads are considered (i.e., the dead load of the structure plus ordinary live loads). It is also common engineering practice to design footings to have a factor of safety of 2.0 when considering the combined effects of dead load, live load, and loads with a low probability of occurrence such as earthquake loads.278 The NRC Staff consider these factors of safety to be adequate for nuclear power plant applications.279 145. Dr. Hendron's testimony includes calculated factors of safety for static loads and for combined static and earth-quake loads. Factors of safety were calculated for earth-quake loads resulting from the FSAR SSE and for earthquake loads equal to 1.5 times the FSAR SSE values. 80 Factors of safety were also calculated neglecting the effect of permanent dewatering, and also taking credit for permanent dewatering.281 The calculations were performed using a number of different 277 Hendron, prepared testimony on bearing capacity at

p. 14, following Tr. 8586, Hendron, Tr. 8587-8588, 8631-8633.

278 Hendron, prepared testimony on bearing capacity at pp. 23, 25, following Tr. 8586; Hendron, Tr. 8606-8608. A factor of safety of 1 means that bearing capacity failure is just beginning to occur.

279 Kane, Tr. 8726, 8731.

280 Hendron, prepared testimony on bearing capacity at pp. 22-27, following Tr. 8586; Hendron, Tr. 8602-8603.

281 The factor of safety increases when permanent dewater -

ing is taken into account. Hendrcn, prepared testimony on bearing capacity at pp. 23-27, following Tr. 8586; Hendron, Tr.

8603-8604.

-115-soils test results.282 All of the factors of safety for static loads were greater than 3.0.283 All of the factors of safety for combined static and earthquake loads were greater than 2.0.284 146. The NRC Staff has concluded that there have been sufficient borings to provide a valid basis for conclusions concerning the bearing capacity of the DGB footings. The Staff is in agreement with the methodology used by Dr. Hendron, which Mr. Kane testified is widely accepted in the engineering profession and is widely used for all nuclear power plants.286 Acting for the NRC Staff, the Corps of Engineers checked Dr.

Hendron's mathematics.287 The NRC Staff agrees that Dr. Hendron used the correct shear strengths as input to the calculations.288 Based on the foregoing, the NRC Staff has concluded that an 282 Hendron, prepared testimony on bearing capacity at pp. 6-8, 14-22, following Tr. 8586; Hendron, Tr. 8609-8615.

Soils tests taken after the surcharge showed a slight increase i in shear strength due to increases in density caused by the surcharge. Hendron, Tr. 8606, 283 Hendron, prepared testimony on bearing capacity at i

pp. 22-24, following Tr. 8586.

284 Hendron, prepared testimony on bearing capacity at pp.

24-26 and Table 5, follcwing Tr. 8586; Hendron, Tr. 8602-8206.

l 285 Kane, Tr. 8817-8818.

6 Kane, Tr. 8840.

287 Kane, Tr. 8800-8801, 8830.

Kane, Tr. 8797, 8800-8802. Shear strength values in the calculations were based on laboratory tests performed before and after the surcharge. Hendron, prepared testimony on bearing capacity at pp. 6-8, following Tr. 8586. Following the surcharge, the Corps of Engineers observed the taking of one set of borings from which samples were recovered for laboratory tests. In accordance with its standard practice, the NRC Staff reviewed the laboratory results and found them to be reasonable.

t Dr. Hendron performed one set of bearing capacity calculations I based exclusively on these results. Kane, Tr. 8802, 8843-8844.

-116-adequate margin of cafety against bearing capacity failure is available.289 E. STRUCTURAL REANALYSIS OF DGB 147. Dr. Peck and Dr. Hendron both testified that, in their opinion, the DGB is a safe structure which has not been damaged by the surcharge program.290 In addition, Applicant presented three expert structural engineers who provided de-tailed analyses showing that the DGB is structurally adequate to perform its intended function over the forty year operating life of the Midland Plant, taking into account the settlement which has occurred and is predicted to occur. Mr. Karl Wiedner, Chief Civil / Structural Engineer in Bechtel Power Management and former Chief Civil / Structural Engineer in Bechtel's Ann Arbor Area Office, presented testimony describing the structural reanalysis of the DGB performed by Bechtel using finite element analytical techniques.291 Dr. Mete Sozen, Professor of Civil 289 SSER #2, 9 2.5.4.5.1, pp. 2-39 to 2-40; Kane, Tr.

8797. The effect of the surcharge was to improve the shear strength of the cohesive soils beneath the DGB and thus improve the bearing capacity. However, this was not the major purpose of the surcharge since the problem at the Midland DGB is settle-ment, not bearing capacity. Kane, Tr. 8797-8800, 8803-8804, 8735-8736, 8738; Hendron, Tr. 8606, 8590-8591.

O Dr. Peck testified that in his view, the DGB "is as good a building today as it was [before the surcharge]." Tr.

3272-3273. See also Peck, Tr. 3475-3476, 10271; Hendron, Tr.

4104.

291 Mr. Wiedner's prepared testimony is bound into the record following Tr. 10790. Mr. Wiedner has over thirty years' experience as a civil / structural engineer, which has included work on reactor buildings and other structures for the Dresden, Hallam, Big Rock Point, Tarapur, Monticello, Trojan and Midland nuclear power plants.

-117-Engineering at the University of Illinois, sponsored testimony evaluating the effect on structural strength of cracks in the walls of the DGB. An independent evaluation of the cracking in the walls of the DGB was provided by Dr. W. Gene Corley of the Portland Cement Association.293 148. To account for the effect of the observed and pre-dicted settlement on the DGB, Bechtel performed a structural reanalysis. This followed the same two step approach described by Dr. Kennedy, supra paragraph 60, in that two mathematical models of the DGB were used. A dynamic lumped-mass model was used to generate seismic forces in the DGB, given as input ground motions the FSAR SSE and OBE.294 A more detailed, -

292 Dr. Sozen's prepared testimony on DGB is bound into the record following Tr. 10950 and was offered in his capacity as a private consultant to Bechtel Power Corporation and not on behalf of the University of Illinois. He is a member of the National Academy of Engineering, American Concrete Institute

. ("ACI") Committee 318, and the Veterans Administration Advisory l Committee on Structural Safety. His extensive research experience relating to the behavior of prestressed and reinforced concrete structures is summarized in the affidavit dated November 11, 1982 accompanying his DGB testimony, and in the resume attached to Applicant's auxiliary building testimony, following Tr. 5509.

293 I Dr. Corley's prepared testimony is Attachment 4 to l

Dr. Sozen's prepared testimony on DGB, following Tr. 10950.

l Dr. Corley has an M.S. and Ph.D in structural engineering from l the University of Illinois and over twenty years of experience as a structural engineer. He is a member of ACI Committee 318 and the ACI Technical Activities Committee, which has the i

responsibility for reviewing and approving all technical changes i in all ACI codes and specifications, including ACI 318 and ACI i 349. Dr. Corley's professional qualifications can be found in his affidavit and resume dated November 12, 1981 attached to Applicant's auxiliary building testimony, following Tr. 5509, 294 Wiedner, prepared testimony on DGB at p. 6 and Figure DGB-9, following Tr. 10790. Bechtel also performed an analysis using 1.5 times FSAR SSE values, which showed the DGB would remain within code allowable stresses. However, Bechtel has not analyzed the DGB for the SME earthquake. Wiedner, prepared testimony on DGB at p. 29, following Tr. 10790; Tr. 10787-1079; Tr. 10833-10837; Tr. 10944-10945.

l

-118-static, finite element model was then used to assess the effect of seismic and other appropriate loads and load combinations on individual elements of the DGB.

149. Applicant's dynamic analysis of the DGB was not controversial. The dynamic model used was a stick-type, lumped mass model using beam elements to represent the struc-tural stiffnesses and impedence functions to represent the foundation medium. The effect of soil-structure interaction was accounted for using impedence functions derived in accor-dance with standard Bechtel design procedures which have been reviewed and approved by the NRC Staff. A very wide range of soil properties was used in the seismic analyses to account for the effects of insufficient compaction and surcharging. In the initial DGB analysis, an upper bound shear wave velocity value of 1,359 ft/sec. was used, corresponding to the shear wave velocity in the underlying till. Subsequent seismic analyses were performed using shear wave velocity values of 796 l ft/sec. and 500 ft/sec. The highest seismic acceleration was produced by the analysis using a shear wave velocity of 796 ft/sec. This maximum structural acceleration was then con-servatively assumed to occur in each element in the static finite element model discussed below, in the north-south, east-west, and vertical directions. These directional responses were then combined using the square root of the l

l l

l 295 Weidner, prepared testimony on DGB at pp. 6-7 and l

Figure DGB-6, following Tr. 10790.

l l

-119-sum of the squares method recommended in Regulatory Guide 1.92.296 150. The second step of Bechtel's structural reanalysis employed a static, elastic, finite element model of the DGB.

This analysis method divides a structure's components into discrete elements of finite size, each having its own struc-tural properties such as thickness, material properties such as modulus of elasticity, and Poisson's ratio of lateral and vertical strains. The elements are connected at common points called nodal points.297 Boundary elements (" springs") are used at the soil structure interface.298 In general such a model serves as a construct which simulates the behavior of the '

building within a given set of assumptions. For example, the model can be used in one role where one feeds in an external load and gets out of the analysis an internal stress or a 296 Wiedner, prepared testimony on DGB at pp. 21-24, 32, 36, Table DGB-3, and Figure DGB-9, following Tr. 10790. In addition, conservative floor response spectra were generated for the DGB by combining in an enveloping fashion the floor response spectra developed using the wide range of soils prop-erties described above. Wiedner, prepared testimony on DGB at pp. 23, 32, following Tr. 10790. The NRC Staff approved Applicant's dynamic analysis of the DGB, including the range of soil properties. SSER #2, Staff Ex. 14, 5 3.8.3.4, p. 3-24; Rinaldi, Tr. 11156-11157.

297 Wiedner, prepared testimony on DGB at p. 25 and

Figure DGB-6, following Tr. 10790.

t 298

( Wiedner, prepared testimony on DGB at pp. 12, 16-17, j 18, following Tr. 10790. See also SSER #2, Staff Ex. 14, l 5 3.8.3.4; Burke, Corley, Gould, Johnson and Sozen, prepared

( testimony on auxiliary building, Volume 1, Appendix B, page B-1, following Tr. 5509. Actually, two sets of springs are normally calculated, one to simulate the response of the struc-l ture to short term loadings, such as earthquake or tornado, the l other set for long-term loads and settlement.

I

1

-120-l displacement.299 Alternatively, the model can be used by feeding in a displacement and calculating internal stresses, and sometimes if necessary corresponding external loads.300 It was the propos-ed use of the finite element model in this second mode, using measured and predicted settlements to estimate stresses in the DGB, which proved to be controversial in this proceeding.301 151. Bechtel accounted for settlement effects in the DGB l

l finite element model by using vertical springs at 84 locations along the building footings as boundary elements. Varying soil properties were represented by calculating an appropriate

spring constant for each spring in the following manner. At I

' 299 Sozen, Tr. 10953. In this mode, external loads are applied to the model as either surface loads on the elements or nodal loads at specific nodal points. Displacements of the nodal points are then calculated, from which element forces and stresses are determined. A computer program called "BSAP" is used to solve the very large set of linear, simultaneous force-displacement equations involved in this analysis technique.

Wiedner, prepared testimony on DGB at p. 25, following Tr. 10790; Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building, Volume 1, Appendix B, following Tr. 5509.

300 Sozen, Tr. 10953. The external loads required to make the model conform to the postulated displacements may in some cases be hypothetical (i.e. physically impossible) indicating errors in the model or in the input displacements. See Sozen, Tr. 10967-10969, and paragraph 166 infra.

301 Applicant's settlement analysis divided the life of the DGB into four periods, beginning with the availability of I the first survey data on March 28, 1978 and ending in December, 2025. Each period required the use of a distinct set of measured or predicted settlement values. For the first period of time, a longhand analysis was performed to account for loads due to settlement of the partially completed structure prior to the halt of construction on the DGB in August, 1978. Applicant used finite element modeling techniques described in the text above only for the subsequent three periods of time.The settle-ment loads calculated for each of these four periods of time were combined to form one settlement term, and then combined with other load cases (e.g. tornado, seismic, etc.) as described in paragraph 152 infra. See SSER #2, Staff Ex. 14, 9 3.8.3.4, pp. 3-25 to 3-26; Wiedner, prepared testimony on DGB at pp.

14-17, following Tr. 10790.

l .-

-121-each spring location, an initial value for the spring constant was chosen by dividing the long term structural load at that point by a measured or predicted settlement value.302 Use of these initial values for the spring constant in the finite element model caused the model to assume a certain deflected shape at the soil structure boundary. Through an iterative process, the spring values were recalculated until the shape of the model at the soil-structure interface fit within the error band of the measured or predicted settlement values. In this way the DGB finite element model was made to assume a shape consistent with, but not identical to, the measured or predicted settlement values.303 As discussed in more detail in paragraphs 162-180 below, this aspect of Bechtel's finite element analysis was the cause of disagreement among the NRC Staff witnesses.304 02 Wiedner, prepared testimony on DGB at pp. 16-17, and Figures DGB-7, DGB-8A, DGB-8B, DGB-8C, following Tr. 10790; Wiedner, Tr. 10807-10812. The settlement values used in the initial calculation of spring constants at the 84 spring loca-tions were taken from a straight line straddling the ten ob-servation points at which settlement had been measured and

! predicted. The straight line was produced on a mathematical l basis by linear regression. Wiedner, Tr. 10809, 10811. See also Kane, Tr. 11184-11185.

303 Wiedner, prepared testimony on DGB at p. 17, Figures l

DGB-8A, DGB-8B, DGB-8C; Wiedner, Tr. 10808-10810. Because of j the enormous stiffness of the DGB, as reflected in the finite

! element model, the final calculated shape has only slight curvature, but it is not a straight line Wiedner, Tr. 10811-10812; Tr. 10393-10399. The final calculated shape actually

( exceeds the error band in several cases, but only by a minis-

! cule amount (about .015 inch). Wiedner, Tr. 10909-10911, l 10930-10934; Peck, Tr. 10399-10400.

304 See Kane, Tr. 10521-10523; Kane and Singh, Tr. 11174-11193; Rinaldi, Matra and Harstead, prepared testimony on the

Structural Adequacy of the DGB at the Midland Site (hereinafter

" prepared testimony on the structural adequacy of the DGB") at pp. 6-7, following Tr. 11086, Tr. 11087-11169; Schauer, Tr.

11169-11172.

-122-152. In its structural reanalysis of the DGB, Bechtel considered dead loads, live loads, wind loads, tornado loads, thermal effects, earthquake loads (from both the FSAR OBE and FSAR SSE) as well as the effects of settlement. These loads were combined in accordance with two sets of load combinations.

The first set of load combinations, which Applicant referred to as the " Midland Acceptance Criteria", was derived from the ACI 318 code, with four additional load combinations which consi-dered the effects of settlement in conjunction with long-term operating conditions and with either wind load or OBE. A second, more stringent, set of load combinations was based on the ACI 349 code, as supplemented by Regulatory Guide 1.142.*

ACI 349, as supplemented, includes the effects of settlement in all load combinations, and therefore unlike the Midland Accep-tance Criteria settlement effects are added to extreme loads such as tornados and SSE. The allowable material limits under both ACI 318 and ACI 349, as supplemented, are the same: for the DGB reinforcing steel ("rebar"), 90% of the yield stress, I

or 54 ksi; for the DGB concrete, a maximum allowable strain level of .003 ksi.305 For both sets of load combinations 305 Wiedner, prepared testimony on DGB at pp. 7-12, 33-34, following Tr. 10790. ACI 318, " Building Code Requirements for Reinforced Concrete", was approved for use on the Midland pro-ject at the time the construction permits were issued and is incorporated by reference in Applicant's FSAR. The NRC Staff's current acceptance criteria are found in ACI 349, " Code Require-ments for Nuclear Safety Related Concrete Structures", as modi-fied by Regulatory Guide 1.142. SER $ 3.8.3, p. 3-21, Staff Ex. 14; Rinaldi, Matra and Harstead, prepared testimony on the structural adequacy of the DGB at p. 3, following Tr. 11086.

Applicant's commitment to check the structural adequacy of the

! DGB using ACI 349, as modified, was made in February 1980.

l Wiedner, prepared testimony on DGB at pp. 9-10, 34-35. See also Joint Exhibit 5 and Tr. 10902-10904.

i

-123-Bechtel's structural reanalysis of the DGB showed that tensile rebar stresses and concrete compressive stresses were less than the code allowable values.306 153. In addition to Bechtel's structural reanalysis of the DGB using finite element techniques, Applicant presented indepen-dent evaluations of the structural integrity by Dr. Sozen and Dr. Corley. These evaluations relied on the observed condition of the DGB rather than any modeling technique. Both experts concluded that the DGB as it presently stands is structurally sound and should be able to serve for 40 years without any problems.307 154. The concrete cracks which have been observed in the DGB are described in detail in Dr. Corley's testimony. 08 Dr.

06 Wiedner, prepared testimony on DGB at pp. 26-28 and Tables DGB-4 and DGB-5, following Tr. 10790. In addition Bechtel's analysis shows the DGB is capable of withstanding a

, seismic event 50% larger than the FSAR SSE and remaining within code allowable stresses. Wiedner, prepared testimony on DGB at

p. 29; Wiedner, Tr. 10941, 10944-10945.

307 Sozen, prepared testimony on DGB (including Dr.

Corley's testimony as Attachment 4), following Tr. 10950; Tr.

10957, 10960-10961.

308 The cracks in the DGB, some of which the Board itself has observed, are hairline cracks visible only cn close inspec-tion of the walls. Some of these cracks are believed to extend completely through the DGB walls. In 1978 when the DGB was hung up on the duct banks the maximum crack width was 0.028 inch. When the duct banks were separated from the DGB footings, a general reduction in width of the larger cracks near the duct banks was observed. Since that time several crack mappings of l the structure have disclosed no significant changes in the i crack patterns. This is true even though some new cracks may have been caused by the surcharge program, and some cracks may have extended in length and increased or decreased in width due to temperature, humidity variations and continued concrete shrinkage. Crack width measurements are subjective and difficult (Footnote 308 continued on page 124) 1 i

L

-124-Corley attributes these cracks to two causes: the restrained volume changes that normally occur during curing and drying of concrete; and reported differential settlement between the duct banks and the north and south portions of the DGB prior to the time that contact between the duct banks and the DGB footings were eliminated in November, 1978.309 Dr. Sozen and Mr.

Wiedner also agree with this conclusion.310 In fact, Dr.

Sozen's testimony shows through simple calculations that at an intermediate construction stage, with the footing resting on the duct bank, normal horizontal tensile stresses in the walls (Footnote 308 continued from page 123) -

to make and this also accounts for some of the differences in crack maps of the same walls performed at different times. In February 1982 the maximum measured crack width was 0.025 inch.

Dr. Sozen testified that in general, a crack width of about 0.060 inch could indicate yielding in the associated reinforce-ment. However, this is not equivalent to structural distress.

No particular crack width should be used as a criterion for structural distress. Wiedner, prepared testimony on DGB at pp.

30-31, following Tr. 10790; Wiedner, Tr. 10859-10865, 10875-10877; Sozen, prepared testimony on DGB at p. 6, following Tr.

10950; Tr. 11003-11006; Corley, prepared testimony on DGB (Attachment 4 to Sozen's prepared testimony) at pp. 4.14, 4.30, l following Tr. 10950; Corley, Tr. 10984-86.

09 Corley, prepared testimony on DGB (Attachment 4 to Dr. Sozen's prepared testimony), at pp. 4.34, 4.11, following Tr. 10950. The crack patterns attributed to differential settlement between the duct banks and the DGB are found in several north-south walls of the DGB, especially the center north-south wall. Corley, prepared testimony on DGB (Attach- ,

ment 4 to Sozen's prepared testimony), at 4.27 and Figure 4.21; Tr. 10980-10984. Although some of the cracks in the DGB are inclined, there is no evidence of any shear failure mechanism.

Tr. 11062-11063.

310 Sozen, prepared testimony on DGB at pp. 1, 5-6; following Tr. 10950; Tr. 10962-10970; 10989-10990; Wiedner, prepared testimony on DGB at pp. 28-29, 32, following Tr.

10790; Tr. 10875-10877.

-125-would have caused the observed cracks near the duct banks, if those cracks had not occurred earlier in fresh concrete.311 155. Dr. Sozen's testimony also contains an estimate of residual tensile stresses in the DGB wall reinforcement based on empirical relationships between crack widths and stresses.

Although he emphasized that any quantitative inference made on that basis must be treated as a very rough measure, Dr. Sozen estimated that the residual tensile stresses in the DGB rebar are likely to be less than 30 ksi and certainly are within the linearly elastic range of the DGB rebar.312 156. More importantly, Dr. Sozen explained that the exis-tence of cracks and the residual stresses they imply does not mean that the strength of the DGB is less than that assumed in the design. This is because reinforced concrete structures are designed and built with the explicit assumption that concrete will crack.313 Therefore the basic premise in the design of reinforced concrete is that all normal tensile forces are 311 Sozen, prepared testimony on DGB at pp. 1, 6-10, l following Tr. 10950.

312 Sozen, prepared testimony on DGB at pp. 2, 10-14, and 1

i Attachments 1 and 3, following Tr. 10950. See also Tr. 10986-10988, 11052-11054.

313 Sozen, prepared testimony on DGB at pp. 2, 14-16, and Attachment 1, p. 1.3, following Tr. 10950. Indeed, Dr. Sozen states that "it is a statistically established truth that hardened concrete is likely to contain cracks especially at planes not having sustained compressive stress. This mecha-nism . . . can occur without the necessity of stress generated by load or imposed deformation." Sozen, prepared testimony on

, DGB, Attachment 1 at p. 1.3, following Tr. 10950. This happens l because of shrinkage and temperature stresses. Sozen, prepared testimony on DGB, Attachment 1 at pp. 1.1 to 1.3, following Tr.

10950; Sozen, Tr. 10969-10970.

l l

-126-resisted entirely by the reinforcement and not by the concrete.

There is overwhelming evidence from the field and from the laboratory which indicates that reinforced concrete structures develop their design strength, even if they are cracked, pro-vided the structure has been proportioned and detailed to resist the design load combinations. Dr. Sozen's testimony explains why this is so.314 157. Finally, Dr. Sozen emphasized that because the exis-tence of discontinuities in the concrete is a condition antici-pated by the ordinary methods of design for reinforced concrete structures, a crack in a reinforced concrete wall or beam is not comparable to a discontinuity in, for example, a steel plate-girder. Continuity in tension of reinforced concrete structures is effected not by the concrete but by the reinforcing bars.

A necessary corollary of this observation is that there is no need to reanalyze the building using a model to reflect the effects of tensile discontinuities implied by the cracks.315 158. Applicant's witnesses did not go so far as to say that cracking is never important for any reinforced concrete structure. They did testify that in their expert judgment, the 314 Sozen, prepared testimony on DGB, especially Attach-ment 2 and pp. 2.3, 2.11, following Tr. 10950. Dr. Sozen's comments on the propensity of reinforced concrete to crack and the principles underlying reinforced concrete design are seconded by Mr. Wiedner in his prepared testimony at pp. 28-29, follow-ing Tr. 10790, and Tr. 10877-10879. In addition, Attachment A to Mr. Wiedner's testimony summarizes the evidence which shows that such cracks do not reduce the ability of the DGB to with-stand tornado missiles.

315 Sozen, prepared testimony on DGB at p.2, following Tr. 10950.

-127-cracks in the DGB are not of the type which indicate that structural distress is on the way or that the DGB's strength has decreased.316 159. The likelihood of future settlement induced cracking in the DGB has been reduced by releasing the duct banks from the structure which allowed unrestrained settlement, by apply-ing the surcharge which consolidated the plant fill, and by completing the structure which provided additional strength and stiffness.317 Initially, because of the difficulty of measur-ing crack widths accurately and the fact that crack widths will change due to seasonal variations in temperature and humidity and also because no underpining operations are planned for the DGB, no crack monitoring program was proposed for the DGB.

Instead, Applicant proposed to confirm continued structural integrity by relying on regular measurements of differential settlement over the 40 year life of the plant to ensure that actual differential settlement is within the predicted limits used in Bechtel's structural analysis.318 At the hearings, 316 In general, cracks in reinforced concrete structures could be important if they indicated general yielding of the rebar or if they were related to imminent failure in shear or bond. The DGB cracks are not of this type. Sozen, prepared l testimony on DGB at pp. 14-15, following Tr. 10950; Sozen, Tr.

10966-10967, Tr. 11003-11005; Wiedner, Tr. 10875. Mr. Wiedner testified that concern about concrete cracking diminishes after the cause of cracking has been established and remedial actions have been taken as described in the text above. Wiedner, prepared testimony on DGB at pp. 28, 32, following Tr. 10790.

See also Peck, Tr. 3475-3476.

317 Wiedner, prepared testimony on DGB at p. 32, follow-ing Tr. 10790. But see Lccley, Tr. 11212-11213.

318 Wiedner, prepared testimony on DGB at pp. 30-31, fol-lowing Tr. 10790; Corley, prepared testimony on DGB (Attachment 4 to Dr. Sozen's testimon**), at p. 4.33-4.34, following Tr. 10950.

-128-however, Applicant agreed at the Staff's request to monitor cracks in specified locations of the DGB on a yearly basis for five years and at five year intervals thereafter. Acceptance criteria were established with appropriate actions defined in the. event such limits are exceeded.319 Applicant has also com-mitted to a repair program for concrete cracks in the DGB and other Seismic Category I structures affected by soil fill which will ensure that the long time serviceability of these struc-tures is not impaired by the presence of such cracks.320 160. The NRC Staff's structural engineering witnesses were Mr. Frank Rinaldi of the NRC Staff, Mr. John Matra of the Naval Surface Weapons Laboratory, and Dr. Gunnar Harstead of Harst'ead Engineering Associates, Inc.321 (Hereinafter, these witnesses 319 Tr. 11068-11070; Applicant's Ex. 29R; Tr. 11222.

320 Corley, prepared testimony on the Midland Concrete Wall Crack Repair Program (hereinafter " prepared testimony on the crack repair program"), which should follow Tr. 11204 (In Applicant's copy of the transcript, this testimony is erroneously bound into the record following Tr. 11206). The NRC Staff has approved Applicant's crack repair program. SSER #2, Staff Ex.

14, 5 3.8.3.4, p. 3-29. The primary reason for repairing cracks is to prevent rebar corrosion, although no conclusive evidence indicates that any relationship exists between rebar widths and corrosion. The repair program exceeds the recom-mendations of Dr. Corley, who had not seen any cracks in the DGB which he felt presented a risk of corrosion. Corley, prepared testimony on the crack repair program, Attachment 1 at pp. 12, 16-17 and Attachment 2 following Tr.11206; Corley, Tr.

11216-112117, 11221-11222.

21 Rinaldi, Matra and Harstead, prepared testimony on structural adequacy of the DGB, following Tr. 11086. Mr.

Rinaldi is a senior structural engineer with the NRC. Mr.

Matra is also a structural engineer, acting in this case as a consultant to the NRC. Their professional qualifications are found following Tr. 5944 and 6124. Dr. Harstead's professional qualifications are attached to the Rinaldi, Matra and Harstead prepared testimony following Tr. 11086.

-129-are collectively referred to as "the NRC Staff structural reviewers"). They were joined on the witness stand by Dr.

Franz Schauer, Branch Chief of the Structural Engineering Branch, Division of Engineering, Office of Nuclear Reactor Regulation, USNRC. The Board also heard comments on the structural evaluation of the DGB from Mr. Joseph Kane, geo-technical reviewer for the office of Nuclear Reactor Regula-tion, Mr. Hari Singh of the Corps of Engineers, a geotechnical consultant to the Office of Nuclear Reactor Regulation, and Dr.

Ross Landsman, a soils specialist in the NRC's Office of Inspec-tion and Enforcement, Region III.323 (Hereinafter, Mr. Kane and Mr. Singh are referred to as "the NRC Staff geotechnical' reviewers").

161. The NRC Staff's position in this proceeding was that, taking into account its current condition, predicted future settlement, and the design loeds, the DGB is acceptable.324 322 See Tr. 11146-11173.

323 See Kane, Tr. 10521-10523; Kane and Singh, Tr. 11174-11193. Mr. Kane is not a structural engineer. Tr. 11187. Mr.

Singh, although he was retained by the NRC as a geotechnical consultant, is also a structural engineer. Tr. 11189-11190.

Mr. Kane's professional qualifications are described in attach-ment 1 to his prepared testimony on Stamiris Contention 4B, I following Tr. 3484. Mr. Singh's professional qualifications

! are attached to his prepared testimony on cooling pond dike stability, following Tr. 3488. Dr. Landsman's Statement of l Professional Qualifications has been admitted into evidence as Staff Ex. 20. Mr. Kane and Mr. Hood have testified that within the NRC Staff, Mr. Kane's views are shared by his supervisor in the Geotechnical Branch of the Office of Nuclear Reactor Regula-tion, Dr. Heller. Tr. 12096-12097.

324 Schauer, Tr. 11169-11170; SSER #2, Staff Ex. 14, 5 3.8.3.7., pp. 3-30 to 3-31, and S 1.7, p. 1-2; Hood, Tr.

11077-11078.

-130-The Staff's approval is subject to the results of the Seismic Margin Review.325 In addition, at the Staff's request, Appli-cant will carry out long term settlement monitoring and crack monitoring to confirm the safety of the structure during the operating life of the plant.326 162. Notwithstanding this official NRC Staff position, there was disagreement between the NRC Staff structural re-viewers and its geotechnical reviewers over one aspect of Applicant's finite element analysis. The varying opinions expressed by different Staff witnesses (except Dr. Landsman) are discussed in paragraphs 163-172 below. The official NRC Staff position on Applicant's finite element analysis of settle-ment and the way in which this position was reached are dis-cussed in paragraphs 173-175 below.

163. To account for the effects of settlement, Applicant through an iterative process calculated soil springs which made its finite element model of the DGB assume a shape at the soil structure interface consistent with, but not identical to, the measured or predicted settlement values. This shape was, with miniscule deviations, within the + 1/8" error band assigned by Applicant to the field measured settlement data. Imposing this deflected shape at the soil-structure boundary resulted in calculated stresses due to settlement in the model which, when 325 Schauer, Tr. 11172.

6 Rinaldi, Matra and Harstead, prepared testimony on the structural adequacy of the DGB, at p. 7, following Tr.

11086; Rinaldi, Tr. 11090-11091; SSER #2, Staff Ex. 14, Table 2.8, p. 2-53; Tr. 11068-11070; Applicant's Ex. 29R.

l

-131-combined with stresses produced by other loads, were compared with code allowable values.327 The NRC Staff's structural reviewers had no problems with Applicant's analysis and consi-dered this approach to be consistent with sound engineering practice.328 NRC Staff's geotechnical reviewers disagreed with this use of settlement data. In their opinion, the best avail-able data to use in a structural analysis of the DGB would be the actual measured settlement values and Dr. Peck's predicted settlement values, which had been reviewed and approved by them.329 164. Mr. Kane expressed skepticism about the error band of

+ 1/8" assigned by Applicant to the measured settlement data in the finite element modeling procedure.330 Moreover, Mr.

Kane viewed the modeling procedure used by Applicant to be an example of " good engineering judgment" inappropriately being relied upon to supersede measured settlement data. Although Mr. Kane admitted he was unsure of what happens in the finite element modeling procedure, in his opinion it went wrong at the l first step, in which a straight line produced by linear regres-sion analysis was used to calculate initial values for the soil spring constants. In his view, the subsequent iterations l

327 See paragraphs 151-152, supra.

328 Rinaldi, Matra and Harstead prepared testimony on the structural adequacy of the DGB, at p. 6, following Tr.

11086; Rinaldi, Tr. 11087, 11093, 11104-11105, 11108; Harstead, Tr. 11091-11092; Matra, 11096.

324 Kane, Tr. 10521; Schauer, Tr. 11171.

330 Kane, Tr. 11174-11177.

-132-

} represented an attempt to match the linear regression analysis line rather than the measured settlement values.331 He pointed out that if the final shape of the soil structure interface, so calculated, had actually turned out to be a straight line, I rather than the almost straight line which Applicant actually i

produced, that would be equivalent to assuming the DGB had only I

l undergone rigid body motion. This would eliminate any stresses due to settlement in the structure.332 Mr. Kane believed that he could see in the measured settlement data the effect of discontinuities (soft spots and hard spots) in the soil under the DGB, particularly the presence of the condensate lines, under Bays 1 and 2. He could not see this in the almost straight line which Applicant incorporated in its finite ele-ment models.333 Mr. Kane also testified that Applicant's assignment. of an error band of two tentl.s of an inch to Dr.

Peck's prediction of future settlement of the DGB from Decem-ber 31, 1981 to December 31, 2025 represented an " unnecessary refinement" on that prediction.334 165. Mr. Singh supported Mr. Kane's comments. In addition, he pointed out that even though the DGB is a rigid structure, 331 Kane, Tr. 11182-11186, 11199.

332 Kane, Tr. 10521-10523. In contrast, Applicant's wit-nesses Dr. Peck, Dr. Hendron and Mr. Wiedner all testified that following release of the duct banks and during the surcharge period the settlement of the DGB did in fact result in rigid body rotation. Peck, Tr. 3282; Hendron, Tr. 4064, 4099; Wiedner, Tr. 10863-10864.

333 Kane, Tr. 11177.

334 Kane, Tr. 11176.

-133-it may not be as rigid as Applicant assumed in its structural analysis. Mr. Singh observed that it is necessary to consider the length of the walls of the DGB (up to about 170 feet) which tend to make the structure more flexible than it would appear if only the cross-section height and thickness of the wall are considered. He suggested that if part of the soil support were to be removed from underneath such a wall, or the soil were to become very soft, for a distance of, for example, 50 feet, the long walls would deflect due to the lack of support. Second, Mr. Singh stated that the deflections which are reflected in the measured settlement data have occurred over a period of

, time as the building has been constructed. The rigidity of the structure would have been less when partially completed than when completed. Mr. Singh stated he did not know whether Applicant had properly analyzed the building to account for this effect. Finally, Mr. Singh stated that the presence of cracks in the DGB walls would tend to reduce the rigidity of this structure. He believed this effect should have been accounted for in the finite element analysis.335 166. Each of the concerns raised by Mr. Kane and Mr. Singh has been answered in the record. It is indeed possible to perform a finite element analysis of the DGB using as input the measured settlement data without regard to any error band, as suggested by Mr. Kane.336 Such analyses were independently done by Applicant and by the NRC Staff's structural engineering 335 Singh, Tr. 11177-11181.

336 Wiedner, Tr. 10812-10816.

l

-134-consultant, the Naval Surface Weapons Laboratory 337 In both cases the results were the same. Because of the rigidity of the structure, it required hypothetical, imaginary forces to deform the structure to match the nominal measured values.

Specifically, both Mr. Wiedner and Mr.Matra, who did the analy-ses, testified that in certain areas the soil would have to be pulling the structure down, which is a physical impossibility, to make the model fit exactly the nominal measured values.338 Moreover, the analyses predicted very high stresses in the building, several times greater than yield point stresses, which would cause easily visible structural distress. Observa-tion confirms that there are no signs of such structural distress in the DGB.339 Accordingly, Applicant concluded that use of measured settlement values without regard to measurement error 337 Wiedner, Tr. 10812-10816; Rinaldi, Matra and Harstead, prepared testimony on the structural adequacy of the DGB, at

p. 6, following Tr. 11086; Matra, Tr. 11098-11101, 11108-11111.

The Naval Surface Weapons Laboratories' draft report, "Struc-tural Reevaluation of the Diesel Generator Building Utilizing i

Actual Measured Deflections as Input", was introduced into evidence as Applicant's Ex. 30. (There are no page numbers on this draft report. Applicant has numbered the pages consecu-tively, including the nine page Figure 29, which was later l supplied by the staff. By our count, the summary appears on

p. 5, the conclusions on pp. 87-88, and the total exhibit amounts to 88 pages).

338 Wiedner, Tr. 10814; Matra, Tr. 11103, 11109. See l

also Rinaldi, Matra and Harstead prepared testimony on the structural adequacy of the DGB, at p. 6, following Tr. 11086; Harstead, Tr. 11169; Applicant's Ex. 30 at pp. 5, 19-20, and 87-88.

339 Wiedner, Tr. 10815; Matra, Tr. 11099, 11101-11103, 11108-11109; Applicant's Ex. 30 at pp. 5, 69, 83-85, 87-88.

l t

l l

-135-is totally inappropriate.340 The NRC Staff likewise concluded that the results of such analyses using measured settlement values without regard to measurement error can not reascnably requirements.341 167. In response to Mr. Kane's questions about the error band of i 1/8 inch assigned to the survey data, Mr. Wiedner explained how this value was chosen.342 In response to a 340 Wiedner, Tr. 10814-110816. See also Sozen, Tr.

10953-10956; Corley, Tr. 10956-10957. In fact, Dr. Sozen testified that he didn't need to do a finite element analysis to know that the purported measured settlement values for the DGB would correspond in a linearly contiguous model to very '

high stresses which would impute a problem in the structure which does not in fact exist. Tr. 10953-10955, 10959-10960.

341 Rinaldi, Tr. 11121-11123.

342 The settlement data used in Applicant's finite element analysis came from optical surveys. During early stages of con-struction until November 1978 these surveys were based on scribe marks, which are scratches in the concrete highlighted with paint.

The survey accuracy for this kind of measurement is i 1/8 inch.

The scribe marks were replaced with permanent settlement markers during the period from spring to November 1978. With permanent I settlement markers an accuracy of 1 1/16 inch can be achieved.

, Nevertheless for purposes of the structural analysis an error band of 1 1/8 inch had already been built into the cumulative settlement measurements due to the use of less accurate survey data at the outset. During the surcharge period the permanent settlement markers were covered up by the surcharge and the sur-veyors had to move to temporary markers on the mezzanine floor.

This created added difficulties for the surveyors which reduced the survey accuracy to i 1/8 inch or less. In addition, the transfer of settlement markers was subsequently determined to have resulted in a systematic error of .22 inch, of which approxi-cately half, or 0.10 inch, was added by Applicant to its error band for that period of time. Wiedner, prepared testimony on DGB at Figures DGB-8A and DGB-8B, following Tr. 10790; Wiedner, Tr. 10791-10800. See also Peck prepared testimony on DGB sur-charge at Appendix A (Lenzini), pp. A-20 to A-23, following Tr.

10180. An error band of 0.20 inch was used for Dr. Peck's prediction of future settlement through the year 2025 based on the differences in the projections of the DGB settlement vs.

log-time relationship made by several different people. Wiedner, Tr. 10801-10802. See also paragraph 130, supra.

1

-136-question from the Board, Mr. Wiedner stated that in his judg-ment, this survey accuracy is acceptable for a structural analysis of the DGB provided the user of the data exercises good judgment in how to apply and utilize the data.343 Dr.

Sozen and Dr. Corley supported Mr. Wiedner in this conclusion.

Dr. Sozen testified that based on his experience with finite element analyses and his assessment of the rigidity of the DGB, it would be necessary to have a survey accuracy of one ten-thousandths of an inch before one could apply the nominal measured values directly to the model.344 Dr. Corley agreed, stating that to take numbers that are measured in the field and apply them without recognizing that there is measurement error in them can and does lead to answers that do not make sense in relation to the physical condition of the structure.345 168. Applicant's finite element analysis did not take into account the possible existence of local soft spots or hard spots in the soil beneath the DGB. Dr. Sozen stated that he could believe that there are discontinuities in the stiffness I

of the soil beneath the DGB. However, he and Dr. Corley testi-fied that, apart from the crack patterns resulting from the l temporary duct bank support condition, there is no evidence in j

343 Wiedner, Tr. 10817-10818.

! 344 Sozen, Tr. 10956, 10994-10995.

345 Corley, Tr. 10956-10957.

346 Wiedner, Tr. 10892.

I -. _

-137-the structure of any other hard spots in the soil below.347 In fact Dr. Sozen stated that the DGB is so stiff that it would re-quire competent rock beneath the center of the building and no support at the edges to produce perceptible curvature in the struc-ture.348 Similarly, Dr. Sozen saw no evidence of structural dis-tress attributable to soft spots in the soil beneath the DGB.349 In addition, Applicant tested the ability of the structure to bridge over a local soft spot through the following analysis. In the finite element model the soil-support was assumed to be zero at one point on the south wall of the structure, with spring constants linearly increasing to normal values over 15 foot intervals along the walls in each direction (north, east and west) from that' point.

This resulted in an increased stress of only 5 ksi.350 Mr. Wiedner concluded that soft spots in the underlying soil are not of great importance to the DGB structural strength. 51 The NRC Staff structural reviewers agreed with this conclusion.352 347 Sozen, Tr. 10997, 11058; Corley, Tr. 11058. See also Wiedner, Tr. 10920. In particular, on Dr. Hendron's recommenda-tion prior to the surcharge, the two condensate lines beneath the DGB were cut on the north side of the structure to allow uniform settlement. Hendron, Tr. 4058-4059, 4083-4084; Hood, Tr. 4181. Moreover, Dr. Peck is confident that in the future the DGB will not become hung up on any underground piping. Tr.

10313-10314.

348 Sozen, Tr. 10997.

349 Sozen, Tr. 10970-10972; 11055-11058.

350 Wiedner, prepared testimony on DGB at pp. 29-30, following Tr. 10790; Wiedner, Tr. 10916-10917, 10943.

51 Wiedner, Tr. 10916 352 Rinaldi, Matra, and Harstead prepared testimony on the structural adequacy of the DGB, at p. 6, following Tr. 11086.

The NRC structural reviewers' opinion on this subject was endorsed as the official Staff position. SSER #2, 9 3.8.3.4, p. 3-26.

4

-138-169. With respect to Mr. Singh's concern that the reduced rigidity of the structure during construction be taken into account, Bechtel did in fact analyze the DGB for four different settlement periods, including several construction stages.353 The NRC Staff structural reviewers testified that had the Applicant considered a finer breakdown of construction stages, lower stresses would have been calculated.354 Dr. Sozen ex-plained that if a structure is cast in a deflected shape, there are no stresses.355 170. With respect to Mr. Singh's concern that observed cracks should be incorporated into the finite element model, the NRC Staff concluded that such an analysis where multiple' cracks must be considered is beyond the state of the art.356 However, the NRC Staff conservatively accounted for the presence of the cracks in their structural analysis by adding the residual l stresses calculated from crack widths to the stresses calculated in Applicant's finite element analysis. The results were still within code allowirle limits and therefcre acceptable.357 353 See Footnote 301, supra. See also Applicant's Ex. 30 j at pp. 19-20.

354 Rinaldi, Matra, and Harstead, prepared testiony on the structural adequacy of the DGB, at p. 7, following Tr.

11086.

355 Sozen, Tr. 10969.

356 SSER #2, f 3.8.3.5, p. 3-27.

57 Rinaldi, Matra and Harstead, prepared testimony on the structural adequacy of the DGB, at pp. 2-5, following Tr.

11086. The NRC Staff considered this structural analysis to be conservative because the stresses indicated by the cracks were assumed to result only from settlement. This ignores the fact (Footnote 357 continued on page 139)

-139-171. This failed to satisy the NRC Staff geotechnical reviewers. Although Mr. Kane acknowledged that it was not his responsibility to evaluate the structural adequacy of the DGB and although he admitted that he was not an expert in that area, he questioned the NRC Staff's structural analysis. He observed that evaluating structural adequacy based on crack analysis is not normal engineering practice. He stated that he did not know whether it was a proper analysis. Mr. Kane could not recommend another analysis because in his opinion the state of the art is such that there is no capability to analyze cracked structures 58 other than what has been done for the DGB. Mr. Singh testi-fied that he disagreed with the NRC Staff's structural analysis.

His experience has included maintaining 5000 structures (bridges),

of which at least half were reinforced concrete. Mr. Singh has never relied on stress analysis based on crack width and he be-lieves it is not a recognized practice. In his view there is no formula to calculate stresses in rebar accurately from crack widths, especially in a complex stress system.359 172. In contrast, Applicant's position was that the NRC structural witnesses' approach of adding residual stresses (Footnote 357 continued from page 138) that cracks in the DGB may be caused not only by settlement but by shrinkage, temperature change, creep, etc. In addition, the effects of dead load and settlement were double-counted in the Staff's calculations: once in Applicant's finite element analy-sis and again in the determination of stresses based on crack mapping. Rinaldi, Matra and Harstead, prepared testimony on the structural adequacy of the DGB, at pp. 4-5, following Tr. 11086.

358 Kane, Tr. 11187-11188, 11196-11199.

359 Singh, Tr. 11189-11190, 11202-11203.

-140-calculated from crack widths to the finite element analysis results was too conservative. As deccribed in paragraphs 155-157 above, Applicant's witness Dr. Sozen testified that there is no need to reanalyze the DGB using a model to reflect the effects of tensile discontinuitics implied by the cracks. This is because there is overwhelming evidence from the field and from the laboratory that such cracks do not affect the strength of a reinforced concrete structure.360 Dr. Corley also testi-fied that it is not necessary to take the cracks into account in a finite element analysis which is used to evaluate the condition of the building. The effect of not taking into account such cracking is to give a highly conservative estimate of stresses.200 173. In accordance with the tenets of full disclosure the NRC Staff presented to the Board the full range of opinions among the Staff reviewers and their consultants. However, they also presented the official NRC Staff position, which was as follows:

(a) The NRC Staff believes the actual measured settlement values are the best characterizagggn of settlement at the Midland site 360 Sozen, prepared testimony on DGB at p. 2 and Attach-ment 2, following Tr. 10950.

361 Cor. lay, Tr. 11224-11226. Dr. Corley testified that the effect or cracking is to reduce the stiffness of the struc-ture. Not taking this effect into account results in a model which predicts higher stresses than are present in the real structure. Tr. 11226-11227. See also Applicant's Ex. 30 at pp. 19-20, 87.

362 Schauer, Tr. 11169.

i i

-141-(b) The NRC Staff has not fully relied on these settlement values in any analyses to ascertain the acceptability of the DGB to withstand its design load over the lifetime of the plant. Instead, the Staff has looked at the current condition of the structure to estimate stresses due to settlement. To these it added stresses due to other design loads which are not presently on the structure but which have to be consi-dered. The Staff relied on Applicant's finite element agg}ysis only for the latter stresses (c) The NRC Staff finds the Dgb5to be structurally acceptable (d) The NRC Staff is requiring a program of surveillance of the structure and for its foundation to ensure the continued safety of the structure.365 (e) The NRC Staff takes no position with respect to the acceptability of Appli-can 356 finite element analysis of the DGB (f) The NRC Staff's acceptance of the DGB is subject to Margin Review.gg9 outcome of Seismic 174. It appears that in reaching this official position, the NRC Staff resolved the dispute between its structural and geotechnical reviewers along jurisdictional lines. As explained by counsel for the NRC Staff, the Staff's theory was that the l settlement data, which is the input which the structural engi-t neer uses to do his analysis, is within the expertise of the l

l 363 Schauer, Tr. 11170.

364 Schauer, Tr. 11170, 11171.

365 Schauer, Tr. 11170.

366 Schauer Tr. 11149, 11171.

367 Schauer, Tr. 11172.

-142-geotechnical engineer and not the structural engineer.368 Therefore the NRC Staff geotechnical reviewers were allowed to veto approval by the NRC Staff of Applicant's finite element analysis even though the NRC structural reviewers had no problem with it.369 Similarly, the NRC Staff structural reviewers were allowed to veto direct use of " actual measured settlement values" in the DGB finite element analysis as recommended by the geotechnical reviewers since that approach does not produce reasonable results and can not reasonably be relied upon in determining whether the DGB meets regulatory requirements.

The final official Staff position on the DGB structural analysis is a compromise solution in which the stresses due to settle-ment are inferred from crack widths rather than from Applicant's finite element analysis. Reliance on Applicant's analysis is limited to the stresses calculated for other loads and load combinations. Of course, to the extent Applicant's finite element analysis appropriately reflects settlement, the Staff has' double-counted the effects of settlement.371 175. Like most compromises, the Staff's position failed to satisfy everyone. The basic premise, as stated by Staff counsel, l

368 Tr. 10393-10394. See also Kane, Tr. 10545.

369 Rinaldi, Tr. 11087, 11093, 11104-11105.

370 Rinaldi, Matra, and Harstead, prepared testimony on the structural adequacy of the DGB, at p. 6, following Tr.

11086; Harstead, Tr. 11096-11097; Matra, Tr. 11098-11100, Tr.

11103, Rinaldi, Tr. 11121-11123.

371 Rinaldi, Matra and Harstead, prepared testimony on the structural adequacy of the DGB, at pp. 4-5, following Tr.

11086; Harstead, Tr. 11136.

-143-that it is within the expertise of the geotechnical engineer to dictate how input is used in a structural analysis found at best lukewarm support from the NRC Staff's structural engineer-ing witnesses.372 Applicant flatly disagreed with this pre-mise.373 Moreover, as described above, the compromise failed to satisfy the NRC Staff's geotechnical reviewers, who ques-tioned the Staff's reliance on residual stresses inferred from crack widths, even though the NRC Staff structural witnesses testified that this is an acceptable engineering practice.374 176. This Licensing Board, of course, is not bound by the position taken by the NRC Staff in this proceeding, nor are we concerned with the jurisdictional boundaries between different NRC Staff departments. We agree with Dr. Peck and Mr. Kane that good engineers should cross the rather ill-defined boun-daries between disciplines and follow through in their work.375 In assessing the record the Board has considered what all the witnesses have had to say, keeping in mind each witness's special qualifications, and the conclusions expressed below are based on our assessment of the record as a whole.

177. In our judgment, it is unreasonable to use settlement data in finite element analyses or indeed in any other applica-372 See Rinaldi, Tr. 11095; Matra, Tr. 11096, 11109-11111.

373 Tr. 10394, 10396; Peck, Tr. 10453-10455.

374 Rinaldi, Matra and Harstead, prepared testimony on the structural adequacy of the DGB, at p. 5, following Tr.

11086.

375 Peck, Tr. 10453-10455; Kane, Tr. 11182.

-144-tion without taking into account the measurement error associat- j 1

ed with such data. This is particularly true in an application 1 such as this where it is shown that use of the data without consideration of error bands requires one to postulate ficti-tious forces and leads to physically unreasonable results. We j think it is even less reasonable that settlement predictions through the year 2025 should be treated as if there is no error band at all associated with the predictions. The assignment of error bands to measured and predicted data is not an "unneces-sary refinement" on such data; instead it is an essential element of the scientific method. If we ignore the uncertainty in such data we are pretending to know more than we actually-do, and this does not lead to correct, or even conservative decisions.376 .

178. The question remains whether the accuracy of the survey data or the settlement predictions is sufficient to allow use of the finite element analysis method for a very rigid structure such as the DGB. Mr. Wiedner, Dr. Sozen and the NRC Staff structural witnesses all affirmed that the ac-curacy of the data is adequate as long as it is used in the manner Applicant used it.377 In addition, Dr. Sozen made the 376 As Dr. Harstead emphasized, the error band in the deflection points is broad enough so that if these points were actually used in the analysis as the NRC geotechnical reviewers suggested, the calculated stresses would be off by a very wide margin. Even if the stresses came out low, he would not trust them. Harstead, Tr. 11097, 11102.

377 Wiedner, Tr. 10817-10818; Sozen, Tr. 10994-10995; 10998-11000.

-145-important point that the purpose of the finite element analysis is not to predict exactly what the stresses in the structure are going to be. Instead, the purpose of the analysis is to shcw that given the differential settlement, the DGB would be acceptable according to the code of practice for designing safety-related nuclear power plant structures. The exercise essentially produces a comparison of the DGB to the ordinary norms of engineering practice for nuclear power plants, rather than the kind of exact prediction one would attempt to achieve in the laboratory.378 Despite the limited accuracy of the analysis, the safety factors built into the entire chain of calculations, for example in Dr. Peck's prediction of future

settlement, in the postulated load combinations, and in the code allowable stress value of 54 ksi, means that the analysis gives a very conservative description of the strength of the structure.

t 179. The Board also concludes on the basis of Dr. Sozen's and Dr. Corley's testimony that the observed cracks in the DGB l have not reduced its strength. That being the case, we find that the NRC Staff's addition of residual stresses calculated I

378 Sozen, Tr. 10998-11000, 11003. See also Rinaldi, Matra and Harstead, prepared testimony on the structural ade-quacy of the DGB, at p. 6, following Tr. 11085; Applicant's Ex. 30 at p. 20.

1 379 Sozen, Tr. 11000-11003. In addition the NRC Staff points out that tornado wind loading is the most significant loading for the DGB. Applicant's analysis conservatively i

ignores the fact that such loads would be reduced by the vent-ing which has been provided in the DGB. Rinaldi, Matra and Harstead, prepared testimony on the structural adequacy of the i DGB, at p. 5, following Tr. 11085; Rinaldi, Tr. 11097-11098.

l

-146-from crack widths to the stresses predicted by Applicant's finite element analysis gives an unnecessarily pessimistic measure of the structural condition of the DGB. While we agree that the cracks provide valuable information on the condition of the structure, we believe that the assessment of their significance presented by Dr. Sozen and Dr. Corley is a more reasonable evaluation than the si:nplistic addition of inferred stresses proposed by the NRC Staff.

180. The Board finds that Applicant's finite element analysis is consistent with sound engineering practice and gives results which can be relied upon to the extent indicated by Dr. Sozen (See paragraphs 150, 178 supra). However, the' Board also notes that Applicant's finite element analysis is only one piece of the evidence before us which shows the struc-tural integrity of the DGB. We also have the testimony of Dr.

Sozen and Dr. Corley who have examined the building and indepen-dently of Applicant's finite element analysis results have concluded that the buildinc is cound. Indeed every structural engineer who testified before us on the subject came to the same conclusion. The Board itself has viewed the structure, and while we are not experts in structural engineering, we can not see any structural distress in what Dr. Sozen aptly referred 0

The Staff admits its results are too pessimistic (conservative) for two additional reasons. First, all stresses inferred from cracks are assumed to be due to settlement, which is not true. Second, the Staff's results include the effects of dead load and settlement twice. Rinaldi, Matra, and Harstead, prepared testimony on the structural adequacy of the DGB, at

p. 4, following Tr. 11086.

-147-to as this " big brute of a structure." The Board finds that this is reasonable assurance that the DGB is structurally adequate to perform its intended safety function over the lifetime of the plant.381 181. Stamiris Contention 4.A.1 states:

4. Consumers Power Company performed and proposed remedial actions regarding soils settlement that are inadequate as presented because:

A. Preloading of the diesel generator building

1. does not change the composi-tion of the improper soils to meet the original PSAR specifications; 182. Dr. Peck testified that the acceptance criteria by which he judged the success of the surcharge -- i.e., the dissipation of excess pore pressures and the establishment of the straight line trend in the plots of settlement versus the logarithm of time -- are technically more conservative than the PSAR commitments regarding composition and degree of compaction of the plant fill beneath the diesel generator building.

Specifying the properties and degree of compaction is an ac-I cepted but indirect method to assure that the settlement of a structure placed on the fill will be within tolerable limits; the justification for the method in engineering practice lies 361 Sozen, Tr. 10967. Even though the Board has found that the NRC Staff's addition of stresses calculated from crack widths to Applicant's finite element analysis results results in an overly conservative evaluation of the DGB's strength, we see no need to set aside the agreement between Applicant and the NRC Staff regarding future crack monitoring. See Tr.

11068-11070, Applicant's Ex. 29R.

l

-148-in correlations between the specified properties and the ob-served settlements of buildings where the specifications have been applied. In the case of the diesel generator building the specified composition and degree of compaction become irrele-vant because the actual behavior of the soil as it exists beneath the structure has been proof tested under conditions of static loading at least as severe as those to be experienced in the future. The settlement predictions are based on actual performance of the actual subsoil, without the necessity for reliance on correlations or any other indirect means for judg-ing the behavior of the subsoil in the future.382 183. Mr. Kane's testimony is similar, except that he -

places reliance on the results of laboratory tests rather than on a characterization of the surcharge as a proof test. The NRC Staff is not requiring a demonstration that the surcharged plant fill beneath the DGB meets the original PSAR compaction specifications. However, the NRC Staff is requiring the equiva-lent. The NRC Staff believes the results of laboratory testing demonstrate that the engineering properties of the surcharged fill material (i.e., shear strength and compressibility) are l the same as what the PSAR specifications were intended to accomplish.383 Moreover, the NRC Staff believes that the l surcharge did accelerate the consolidation of the cohesive fill l

382 Peck, prepared testimony on DGB surcharge at pp. 7-8, l

following Tr. 10180.

Kane, Tr. 8796-8799. Mr. Kane estimated that the density of the cohesive soils beneath the DGB now either equals or exceeds PSAR specifications. Kane, Tr. 8799.

l l

[ - - - -

-149-materials and therefore improved the shear strength and bearing capacity of the fill. Surcharging is not effective in increas-ing the density of cohesionless soils, but the potential for liquefaction of the cohesionless soils has been adequately addressed by the installation of the permanent dewatering system, and the potential effect of seismic shakedown on the DGB has been evaluated and found acceptable.384 184. The Licensing Board concludes that demonstrating that the DGB fill materials comply with original PSAR specifications is not necessary. The surcharge did improve the engineering properties of the fill material. Moreover, the results of the surcharge program demonstrate that the fill provides an accept-able foundation for the DGB. This conclusion will be confirmed by a monitoring program throughout the operating life of the Midland Plant.

185. Stamiris Contention 4.A.2. states:

4. Consumers Power Ccmpany performed and proposed remedial actions regarding soils settlement that are inadequate '

as presented because:

A. Preloading of the diesel generator building

2. does not preclude an unaccept-able degree of further differential settlement of diesel generator building; For the reasons stated in paragraphs93-138, supra, the Licensing Board has concluded that Dr. Peck's estimate of 384 Kane, Tr. 8799-8800; Hendron, prepared testimony on bearing capacity at p. 16, following Tr. 8586; Hendron, Tr.

8699. SSER #2, SS 2.4.6, 2.5.4.5.5, 2.5.4.5.6. See paragraphs 140-142 supra.

-150-future differential settlement of the DGB represents a reason-able and conservative prediction. For the reasons stated in paragraphs 147-180, supra, the Licensing Board has concluded that the DGB is structurally adequate to accommodate such further differential settlement. In fact we are persuaded that the DGB has so much reserve strength that even if Dr. Peck's estimate of differential settlement were exceeded, there would likely be no impact on the public health and safety.385 Never-theless, a long term settlement and crack monitoring program over the life of the structure will be included in the Techni-cal Specifications to provide additional assurance that an un-acceptable degree of further differential settlement will not occur.386 186. Stamiris Contention 4.A.3. states:

4. Consumers Power Company performed and proposed remedial actions regarding soils settlement that are inadequate as presented because:

A. Preloading the diesel generator building

3. does not allow proper evalua-tion of compaction procedures because of unknown locations of cohesionless soil pockets;

! 187. To begin with, this subcontention contains a mistake.

If soil really is cohesionless, it will not support a void at depth.387 Moreover, there is no evidence that any voids exist 385 See Peck, Tr. 10281.

386 SSER #2, 6 2.5.4.7.

387 Hendron, Tr. 8656-8657.

-151-in the fill beneath the DGB. Dr. Hendron and Mr. Kane both testified that they are unaware of any such voids disclosed by the numerous borings in the DGB area. In addition, Dr.

Hendron testified that the continuous strip footings of the DGB distribute the structural Icad over a large area and have a capacity to bridge a void. To negatively affect the DGB would require'a big continuous void over a large area.389 Both Dr.

Hendron and Mr. Kane testified that the number of borings which have been taken is adequate to find such a large void if it existed.390 The Licensing Board concludes that there is reason-able assurance that the safety of the DGB is not jeopardized by the postulated existence of "cohesionless soil pockets" in the underlying fill material.

188. Stamiris Contention 4.A.4 states:

4. Consumers Power Company performed and proposed remedial actions regarding soils settlement that are inadequate as presented because:

A. Preloading of the diesel generator building i 4. may adversely affect under-l lying piping, conduits or

! nearby structures.

l 388 i Hendron, Tr. 8658, 8654-8656; Kane, Tr. 8814-8815, l 8817-8818. Ms. Stamiris asked both Dr. Hendron and Mr. Kane

! about an incident on May 19, 1982 in which a void was observed l

during drilling between the DGB and the turbine building. Both witnesses testified that the void was produced by subsidence caused by the drilling procedure and was not pre-existing in the fill. Hendron, Tr. 8646-8649, 8657, 8660; Kane, Tr. 8820-8822.

89 Hendron, Tr. 8658, 8661. See also Kane, Tr. 8816.

390 Hendron, Tr. 8658; see also Kane, Tr. 8816; Wiedner, prepared testimony on DGB at pp. 29-30, following Tr. 10790.

-152-189. The only nearby structure which could have been affected by the DGB surcharge is the turbine building, which is not safety-related. Damage to the turbine building was pre-vented by construction of a retaining wall.391 The effect of the DGB surcharge on underlying piping and conduits is dis-cussed infra, at paragraphs 317-321, 350-351, 365-367 and 417-421.

190. Stamiris Contention 4.A.S. states:

4. Consumers Power Company performed and proposed remedial actions regarding soils settlement that are inadequate as presented because:

A. Preloading of the diesel generator building '

5. yields effects not scientifically isolated from the effects of a rise in cooling water and there-fore not measured properly; 191. The Licensing Board concludes that this contention is not correct for the reasons stated in paragraphs 112-113, supra. The rise in the cooling pond and associated increase in plant area ground water levels during the surcharge period did not make interpretation of piezometer measurements impossible or impracticable or disguise the effects of the surcharge as revealed by these instruments.392 Moreover, the efficacy of SSER #2, $ 2.5.4.4.2; Peck, prepared testimony on DGB surcharge at pp. 27-28, following Tr. 10180; Kane, Tr. 10342-10343.

392 See Peck, prepared testimony on DGB surcharge at pp.

49, 57-58, following Tr. 10180; Peck, Tr. 10197-10199, 3252, 3464-3465. See also Applicant's Proposed Findings of Fact and Conclusions of Law on Quality Assurance and Management Attitude l Issues, dated October 28, 1981, at paragraphs 149-156.

1 I

-153-the surcharge has also been judged by settlement readings.

When interpreting the settlement data it is possible to isolate the effects of dewatering from those of the surcharge.393 192. Stamiris Contention 4.C.(e), as amended by Ms.

Stamiris in her Answer to Applicant's Interrogatories, dated April 20, 1981, states:

4.C. Remedial soil settlement actions are not based on adequate evaluation of dynamic responses regarding dewatering effects, differential soil settlement, and seismic effects for these struc-tures:

e. DGB 193. While this contention is not entirely clear, we interpret it as expressing a number of distinct concerns. The Licensing Board concludes, based on paragraphs93-138, supra, that Dr. Peck's predictions of future differential soil settle-ment for the DGB are reasonable and conservative. As explained in paragraphs 122-125 and 137, supra, Dr. Peck's settlement predictions adequately take into account the effects of dewate-ring. For the reasons given in paragraphs 151-152 and 162-180, l

supra, the Licensing Board also concludes that the way in which

Applicant has used measured and predicted differential settle-l l ment data in its structural evaluation of the DGB is appro-priate.

393 See " Diesel Generator Building Dewatering Settlement Report", dated March 4, 1983, served by Applicant's counsel on April 19, 1983.

l

-154-194. The Licensing Board also concludes that the Applicant has appropriately taken into account the effects of dewatering in its evaluations of seismic shakedown and bearing capacity.394 195. Finally, subject to the outcome of the Seismic Margin Review, the Licensing Board finds that Applicant's seismic analysis of the DGB is adequate. 95 196. Sinclair Operating License Contention 24 states:

The present site for the Midland facility is not only inappropriate for the reasons set forth in Contention 9, but also affirma-tively unsafe. Serious questions have been raised concerning the ground stability of portions of the site. At least one of the essential buildings of the reactor complex is reported sinking, and construction has been halted on that building. As a result '

of the serious and unresolved questions concerning ground stability, the findings required by 10 C.F.R. SS 50.57(a)(3) and 50.57(a)(6) can not be made.

197. In accepting this contention, the Licensing Board stated:

This contention, not objected to by any party, is accepted except to the extent that the first sentence refers to previously rejected Contention 9. This acceptance, l however, is further conditioned by our i agreement with the Staff's comment (Novem-ber 28, 1978 Response, page 6) that the question appears not to be one of site i suitability, but rather of the type of material used by the Applicant under the 394 See paragraphs 139-146, supra.

395 See paragraphs 147-180, especially 148 n.294 and 149, supra. To the extent Stamiris Contentions 4.D.1, 4.D.2 and 4.D.3 raise concerns applicable to the DGB similar to those described in Stamiris Contention 4.C.(e), our ruling is that those concerns have been adequately addressed. See also para-graphs 422 et seq., infra.

-155-building in question. A suitable restate-ment of the. contention shall be provided by the Intervenor at the time required by the schedule below for sugggssion of other restated contentions 198. Contrary to the Licensing Board's direction, Ms.

Sinclair never provided a restatement with greater specificity for her Operating License Contention 24.397 A recent Appeal Board decision calls into question whether in 1979 the Licens-ing Board should have accepted this contention, subject to restatement. See Duke Power Co. (Catawba Nuclear Station, Units 1 and 2) ALAB-687, 16 NRC (1982). However, neither Applicant nor the Staff objected in 1979 to the admis-sion of this contention. Under the circumstances, it seems appropriate to construe this contention as we construed it in 1979, as referring to the sinking of the diesel generator building, rather than referring to all of the soils-related issues which have since been litigated in this proceeding.398 1

199. Based on the findings in paragraphs93-138, supra, the Licensing Board concludes that Dr. Peck's predictions of 396 Special Prehearing Conference Order, dated February 26, 1978 at p. 8.

397 '

Ms. Sinclair did not provide any additional explana-tion of her contention 24 during discovery. See " Mary Sinclair's Replies to First Set of Interrogatories from Consumers Power Co." (undated, approximately August 3, 1982), at p. 2.

398 Special Preliminary Conference Order, dated February 26, l

1978, at pp. 8, 21. In adopting this narrow but consistent construction of rinclair Operating License Contention 24, we hasten to add tha*. we are unaware of any " ground stability" problems which have not been satisfactorily resolved at the Midland site by Applicant and by the NRC Staff in the course of its independent safety review, and which might escape review unless a broader interpretation of Sinclair Operating License Contention 24 were adopted.

-156-future settlement for the DGB are reasonable and conservative.

We also conclude based on paragraphs 147-180, supra, that the DGB is structurally adequate to perform its intended safety functions over the 40-year life of the plant notwithstanding the settlement which has occurred and is predicted to occur.

For the reasons stated in paragraphs 139-146 supra and para-graphs 422 et seq. infra, we find that the DGB is not threat-ened by lack of adequate bearing capacity, seismic shakedown, or liquefaction. Accordingly the Licensing Board concludes, subject to the outcome of the Seismic Margin Review, that the concerns in Sinclair Operating License Contention 24 have been adequately resolved.

200. Marshall Operating License Contention 2 states:

Geological conditions that the Midland Nuclear Plant which is causing the plant to settle (sic).

201 In accepting this contention, the Licensing Board commented:

This is the same issue as Sinclair conten-tion 24. It is accepted as it relates to settlingg(gthe Midland diesel generator building.

202. The Licensing Board concludes that the concerns stated in Marshall Operating License Contention 2 have been adequately resolved for the same reasons recited in paragraph 399 Special Prehearing Conference Order, dated February 26, 1979 at p. 21 (emphasis in original). See also Special Prehear-ing Conference Order at p. 16.

{

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-157-199, supra with respect to Sinclair Operating License Conten-tion 24.400 203. Before her withdrawal from this proceeding, Intervenor Sharon Warren proposed three contentions which were admitted for litigation in this proceeding by the Licensing Board in its October 20, 1980 Order. Because Ms. Warren has withdrawn, her contentions are no longer matters in controversy in this proceed-ing.401 Nevertheless, the Licensing Board will comment on Ms.

Warren's contentions in this Partial Initial Decision.

204. Warren Contention 1 states:

The composition of the fill soil used to prepare the site of the Midland Plant -

Units 1 and 2 is not of sufficient quality to assure that preloading techniques have permanently corrected soil settlement problems. The NRC has indicated that random fill dirt was used for backfill.

The components of random fill can include loose rock, broken concrete, sand, silt, ashes, etc. all of which cannot be com-pacted through pre-loading procedures.

205. Both the NRC Staff's and Applicant's expert witnesses testified that it is not appropriate to refer to the Midland fill materials as " random." Mr. Kane testified that loose rock, broken concrete, or ashes have not been discovered at Midland in the foundations of Seismic Category I structures.

400 Notwithstanding the fact that in 1979 the Licensing Board limited Ms. Sinclair's and Mr. Marshall's contentions to soils rather than geological issues, the NRC Staff addressed concerns raised by Mr. Marshall and by other interested members of the public in limited appearance statements, that there might be subsidence at the plant site as a result of solution mi ling of salt beds by Dow Chemical. See Tr. 1026-1034; Kimball, Tr. 1561-1603, 1610-1612, 4702-4703; Holt, Tr. 4660-4668.

401 See Conclusions of Law, infra.

-158-The concrete which has been identified by borings and excava-tions in the plant fill was intentionally placed during con-struction instead of compacted fill, but this concrete is not in a condition of broken pieces in the large voids that may typically be found in a random or waste fill.402 206. In addition, Dr. Peck testified that surcharging for reducing future settlements of buildings is a widely accepted procedure that has been used under a variety of circumstances.

It has been effective above miscellaneous fill, peat, loose sands and silts, organic materials, lake bed clays, clays, clayey silt, sand, compressible clays interspersed with silt lenses, and loose deposits of free-draining materials consist-ing of boulders, sand, and silt, with blocks of rock. The success of the procedure derives fundamentally from the fact that the compressibility of all earth materials is much smaller during a second loading cycle than during the first.403 Dr.

Hendron and the NRC Staff are in agreement with Dr. Peck that the DGB surcharge improved the engineering properties of the i foundation soils beneath the DGB.404 l

207. Accordingly, if Warren Contention 1 were still a matter in controversy in this case, the Licensing Board would l

402 See Hood, Singh, and Kane, prepared testimony on BWSTs, etc. at p. 17, following Tr. 7444; Kane, Tr. 12076; Peck, Tr. 3223-3224.

403 Peck, prepared testimony on DGB surcharge at p.17, following Tr. 10180.

404 See Hendron, Tr. 4104-4106, 8606; Kane, Tr. 8797-8800.

-159-conclude that Applicant and the NRC Staff have shown that it is not accurate and does not call into question the safety of the DGB.

208. Warren Contention 3 states:

3. Pre-loading procedures undertaken by Consumers Power have induced stresses on the diesel generating building structure and have reduced the ability of this struc-ture to perform its essential functions under that stress. Those remedial actions that have been taken have produced uneven settlement and caused inordinate stress on the structure and circulating water lines, fuel oil lines, and electrical conduit.

209. Insofar as this former contention raises concerns about the structural integrity of the DGE, those concerns have been adequately resolved in preceding paragraphs of this Partial Initial Decision, in particular paragraphs 147-180. The effect of the surcharge on piping and electrical conduit beneath the l DGB is addressed in paragraphs 317-321, 350-351, 365-367, and 1

417-421, infra.

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-160-AUXILIARY BUILDING 210. The auxiliary building is a large structure con-structed mainly of reinforced concrete. It is located north of the turbine building, between the two containment buildings.405 The auxiliary building houses safety-related facilities and equipment and is therefore designed as a Seismic Category I structure capable of maintaining its integrity during and after a design basis accident, including a postulated safe shutdown earthquake.406 211. The main part of the auxiliary building is 155 feet ,

long in a north-south direction. A railroad bay / liquid radwaste area extends 28 feet northward from the main part of the struc-ture. The south end of the auxiliary building consists of a control tower, in line with the main building, and two electri-cal penetration areas extending 90 feet to the east and the west from the control tower.407 405 Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building at p. 7, and Figure Aux-1, following Tr. 5509; Hood, Kane and Singh, prepared testimony on Remedial Underpinning of the Auxiliary Building Area (herein-after " prepared testimony on auxiliary building") at pp. 4-6, following Tr. 5839.

406 Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building at p. 7, following Tr. 5509.

407 Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxil ary building at p. 7 and Fig. Aux-2, follow-ing Tr. 5509; Shunmugavel, prepared testimony on Structural Evaluation of Auxiliary Building for Seismic Shakedown Settle-ment at the Midland Site (hereinafter " prepared testimony on auxiliary building seismic shakedown"), at pp. 2-3 and Figures 1 and 2, following Tr. 11997.

-161-212. A feedwater isolation valve pit ("FIVP") is located at the outer end of each of the two electrical penetration areas. Adjacent to each pit are a containment building, an auxiliary building electrical penetration area, the turbine building and a buttress access shaft. The FIVPs are struc-turally isolated from the surrounding structures. They are C-shaped, with the open end against a containment building, and are constructed of reinforced concrete. The function of the FIVPs is to enclose Seismic Category I feedwater pipe isolation valves.408 213. The main part of the auxiliary building is supported by a reinforced conrete mat foundation, with the base of the-lowest mat resting on undisturbed glacial till at elevation 562. The railroad bay is supported by soil backfill at eleva-tion 630.5. The control tower and electrical penetration areas

' are supported by soil backfill at elevation 609. The FIVPs are supported by soil backfill at elevation 615.409 214. In August 1978, after excessive settlement of the I diesel generator building was detected, Applicant undertook subsurface soil investigations, including soil borings in the vicinity of the auxiliary building.410 A 10 C.F.R. $ 50.55(e) 408 Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building at pp. 8-9 and Figure Aux-2, i following Tr. 5509, 409 Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building at pp. 7-9 and Figure Aux-3, following Tr. 5509; SSER #2, pp. 2-12, 2-13, Tables 2.2 and 2.3.

410 Sec Keeley, prepared testimony on soils settlement, following Tr. 1163.

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-162-interim report disclosing that these soil borings had been made in plant fill areas was submitted to the NRC by the Applicant on November 7, 1978.411 215. To evaluate the backfill under the north and south ends of the auxiliary building three borings were taken in the vici-nity of the railroad bay,412 and twelve borings were taken in the vicinity of the control tower, the electrical penetration areas and the FIVPs.413 On the basis of these borings Applicant deter-mined that the soil under the control tower and railroad bay was sufficiently compacted to support those portions of the auxiliary building. However, some compressible or inadequately compacted layers were found to be present in the soil backfill supporting the electrical penetration areas and the FIVPs. The NRC Staff's own review of the borings led them to conclude that the plant fill was inadequately compacted not only beneath the FIVPs and t

the electrical penetration areas, but also beneath the control tower. In particular, a 1-foot-deep void was discovered in one of the borings beneath the mud mat under the control tower.414 411 Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building at pp. 9-10, following Tr. 5509.

412 Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building at p. 10 and Figures Aux-6 to Aux-8, borings AX-1, AX-2 and AX-10, following Tr. 5509.

413 Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building at Figures Aux-6 to Aux-8, borings AX-3 to AX-9, AX-ll to AX-12, AX-15, AX-18 and AX-19, following Tr. 5509.

414 Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building at p. 10, following Tr. 5509; J. Cook, Tr. 18483; Kane, Tr. 5856; SSER #2, 5 2.5.4.4.1,

p. 2-17.

-163-216. It should be emphasized that the inadequate founda-tion conditions revealed by the 1978 borings have not to date resulted in unacceptable differential settlement or structural distress in the auxiliary building or FIVPs. A Foundation Data Survey Program was established in May 1977 to monitor settle-ment of Seismic Category I structures at the site pursuant to a commitment in the FSAR. The settlement which has occurred at the auxiliary building has not been excessive or unusual. Mea-surements taken pursuant to this program show that the auxiliary building has undergone a small rotation with the south end having settled slightly more than the north end. Sona very small struc-tural deformation may have been associated with this rotation.416 217. In December 1978, a crack mapping program was insti-tuted for all Seismic Category I buildings founded on plant fill. Several crack mappings of the parts of the auxiliary building founded on plant fill and of the FIVPs have neen per-formed pursuant to this program. The cracks which have been observed in the auxiliary building can all be attributed to normal volume change in the concrete. The observed conditions do not suggest any deterioration or distress which would indi-cate any deviation from design conditions.416 415 Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building at pp. 10-11, A-3, and Figure Aux-8A, following Tr. 5509; J. Cook, Tr. 18483; SSER #2, 5 2.5.4.4.1, p. 2-17.

i 416 Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building at pp. 11-12, Figures Aux-9 to Aux-21 and Appendix A, following Tr. 5509; Corley, Burke and Sozen, Tr. 5573-5596, 5729-5749. The NRC Staff was concerned about these cracks but ultimately concurred in the Applicant's

, evaluation of the observed cracks. SSER #2, S 2.5.4.4.1, p.

2-17; $ 3.8.3.5, p. 3-28.

t-

-164-218. Nevertheless, the unsatisfactory plant fill condi-tions revealed by the 1978 subsurface investigations caused concern about future differential settlements. Because the control tower and electrical penetration areas were not de-

, signed to cantilever from the main auxiliary building, such differential settlements could cause unacceptable stresses.417 Applicant chose to undertake remedial structural measures to eliminate the possibility of unsatisfactory foundation condi-tions for the control tower and to correct such conditions beneath the electrical penetration areas and the FIVPs. Under-pinning of the control tower and electrical penetration areas and replacement of the plant fill beneath the FIVPs were select-ed as the best remedial measures for assuring proper foundation conditions for this structure.418 219. The i!nderpinning wall for each electrical penetration area will extend down to undisturbed glacial till at about 417 SSER #2, $ 2.5.4.4.1, p. 2-17; Kane, Tr. 5856-5857.

During hearings on quality assurance and management attitude

! issues, Dr. Ross Landsman, a soils specialist employed by the l Office of Inspection and Enforcement, Region III, volunteered that in his opinion the original design of the auxiliary build-ing, with the control tower and electrical penetration areas resting on plant fill and the main auxiliary building resting at a lower elevation on glacial till, was a " design deficiency".

Because the proposed remedial measures completely correct this alleged deficiency, the issue is not relevant for purposes of this Partial Initial Decision. See Landsman, Tr. 15060, 16305-16320, 16505-16508, 16589-16591.

418 Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building at p. 12, following Tr. 5509; SSER #2, 5 2.5.4.4.1, p. 2-17. The Applicant initially con-sidered a pile and corbel foundation system and then considered a partial underpinning; however, when the need to design for a larger earthquake arose, the present design was arrived at.

Johnson, Tr. 5647-5668, 5729-5733. See also paragraph 232, infra.

-165-elevation 571. Each wall will have a minimum thickness of six feet with an increased thickness at the base to provide greater soil bearing area. The thickness of the base will vary as the north face of each wall curves about the containment leaving a four foot gap for compacted sand fill.419 220. The underpinning wall for the control tower extends down to undisturbed glacial till at elevation 562 and consists of six foot wide by three foot long piers (which provide sup-port during construction operations) and closure portions which interconnect the individual piers to provide a continuous perma-nent underpinning wall. The piers and wall sections are belled out to fourteen feet wide at the base to provide greater soil bearing area. The underpinning walls will form a box in con-junction with the existing south foundation Wall of the main portion of the auxiliary building te which they are attachad.

The control tower underpinning walls will also be attached to the underpinning walls of the electrical penetration areas.420 221. The FIVPs will be supported in a different manner than the control tower and electrical penetration areas. The existing backfill under the FIVPs will be removed and replaced with well compacted granular material to a suitable height l below the existing valve pit mat. A reinforced concrete slab l

419 Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building at p. 12 and Figures Aux-22 to l Aux-25, following Tr. 5509.

420 Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building at pp. 12-13 and Figures Aux-22 to Aux-25, following Tr. 5509.

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-166-will be cast on top of the new fill and jacks will be placed between the slab and the original mat to precompress the new fill. After precompression is complete, the space between the slab and the original mat will be filled with grout and con-crete.421 222. In order to accomplish the underpinning of the con-trol tower and electrical penetration areas and the removal and replacement of the soil backfill under the FIVPs, access shafts must be dug on the west and east ends of the affected area.422 These shafts are located immediately to the north of the tur-bine building and immediately to the west and east of the re-spective west ano east FIVPs. From these access shafts tunnels will be excavated which will allow workers to drift under the turbine building and, as the work progresses, under the elec-trical penetration areas, FIVPs and control tower. The work will progress in a step-wise fashion, tunneling far enough to 421 Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building at pp. 13-14 and Figure Aux-26, following Tr. 5509.

422 The construction of the remedial soils measures has been divided into several phases. As part of Phase I, the Applicant obtained the NRC Staff's concurrence to excavate the access shafts to elevation 609 on November 24, 1981. See SSER

2, Appendix I at I-2. Phase II began on December 9, 1982 when

the NRC Staff, pursuant to the authority granted in this Licens-ing Board's April 30, 1982, Memorandum and Order, LBP-82-35, 15 N.R.C. 1060, authorized the installation and loading of Piers 12E and 12W, the first piers beneath the turbine building. Tr.

11007. Since that time the NRC Staff has been approving further underpinning work on a step by step basis. For a detailed progress report on this work, see Stone & Webster's "Indepen-dent Assessment of Underpinning: 90-Day Report," received into evidence as Applicant's Ex. 33.

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-167-construct the first temporary supports,423 constructing those supports, tunneling far enough to accomplish the next part of the construction, constructing it and so on.424 223. Because excavation under and alongside existing struc-tures is necessary to accomplish underpinning efforts, the construction procedures used include steps to support the soil adjacent to all excavations and to provide temporary support for the affected structures during the construction process.425 224. Also as the excavations necessary for construction of the underpinning extend below the level of the ground water table,426 temporary dewatering procedures are being used to 423 The Applicant obtained the NRC Staff's approval to excavate, pour and load the first east and west temporary supporte under the turbine building on December 9, 1982. See Tr. 11007.

424 For a detailed description of the construction proce-

'dures, the seguencing of the work and the conceptual basis for these procedures, see Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building at pp. 14-28 and Figures Aux-22 to Aux-26 and Aux-30, following Tr. 5509; SSER #2, at pp. 2-17 to 2-23, I-l to I-3 and Figures 2-5, 2-6, 2-7, I-1 and I-2; see also Burke, Tr. 5532-5572.

l 425 In addition to the piers which will be constructed to i provide temporary support for affected structures, a beam and tie system which provides temporary support for the FIVPs is already in place. Also post-tensioning ties have been install-ed on the electrical penetration areas. For a detailed descrip-tion of these two support systems, see Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building, at pp. 16, 26 and Figures Aux-27 and Aux-31, following Tr. 5509; SSER #2, 6 3.8.3.1, at pp. 3-7 to 3-8; Burke, Tr. 5510-5511.

For a detailed desciption of the grillage system which will be used for temporary support for the electrical penetration area, see Burke, Corley, Gould, Johnson and Sozen, prepared testimony l on auxiliary building, at pp. 21-22 and Figure Aux-30, following i Tr. 5509; Burke, Tr. 5542-5545.

426 The ground water table is being maintained at approxi-mately elevation 545 by a permanent dewatering program. For a l detailed description of the permanent dewatering program, see l SER, 9 2.4.6.2.; SSER #2, 9 2.4.6.2, at pp. 2-1 through 2-10, 2-35 and Figures 2-1 through 2-4. See also Rinaldi and Kane, Tr. 12101-12103, 12122.

._ _ _ _ _ _ _ ~. _ . . _ . _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _

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-168-draw down the ground water level in the affected area below the level to which the excavations will extend. A "freezewall" has been constructed by drilling a line of bore holes and circulat-ing a coolant at low temperatures through pipes in the bore holes. The coolant freezes the soil in a narrow strip along the line from elevation 610 down to the undisturbed glacial till. The frozen soil acts as a dam which minimizes seepage of ground water into the excavations from surrounding areas.427 225. Intervenor Barbara Stamiris has expressed certain safety related concerns with respect to the remedial measures the Applicant has proposed,for insuring adequate foundation conditions for the control tower, electrical penetration areas and the FIVPs in her contention 4(c) which states, as amended:

Remedial soil settlement actions are not based on adequate evaluation of dynamic responses regarding dewatering effects, differential soil settlement and seismic effects for these structures: a. Aux.

Bldg. Electrical Penetration Areas agg8 Feedwater Isolation Valve Pits . . .

226. The Applicant has taken into account the leads result-ing from the ground water elevations maintained by permanent dewatering and by temporary dewatering in its design of the remedial soils measures for the control tower, electrical pene-427 For a detailed description of the temporary dewater-ing program, including the freezewall, see Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building at pp. 16-18 and Figure Aux.-28, following Tr. 5509; SSER #2, Appen-dix I, at I-l through I-2; Burke, Tr. 5512-5518.

428 Intervenor Barbara Stamiris' Answers to Applicant's Interrogatories and Amendment to Contentions, filed April 20, 1981, at p. 12.

-,.- - - - . --~

-169-tration areas and FIVPs. The NRC Staff verified that these loads were considered in the design of the remedial soils mea-sures and that the requirements of Standard Review Plan ("SRP"),

section 3.4.2 were complied with during audits conducted at Bechtel Corporation in Ann Arbor, Michigan.429 227. General groundwater drawdown to elevation 595, the level associated with permanent dewatering, resulted in settle-ment of the main portion of the auxiliary building of approxi-mately 0.2 inches. Temporary dewatering for construction pur-poses will result in a further drawdown of about 30 feet, caus-ing from 0.1 to 0.2 inches of additional settlement for the main portion of the auxiliary building, which is founded on '

glacial till. However, after construction of the underpinning is completed the ground water level will be allowed to return to elevation 595, the level which will be permanently maintained, resulting in a heave of approximately 0.2 inches. Both the settlement and heave associated with dewatering will be wide-spread, uniform movements which will have an insignificant l

effect on differential settlement between the main portion and the underpinned portions of the auxiliary building.430 228. Hydraulic jacks will be used to impose loads on the l

underpinning before the control tower and electrical penetra-l

! 429 Rinaldi, prepared testimony on Intervenors' Conten-l tions at pp. 2-3, following Tr. 12080; Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building at

p. 45, following Tr. 5509.

430 Burke, Corley, Gould, Johnson and Sozen, prepared l

testimony on auxiliary building at pp. 55-56, following Tr.

l 5509; see also Peck, Tr. 10461-10463.

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-170-tion areas are finally fixed to the underpinning.431 The jack-ing procedure vill continue until all primary settlement has occurred and only long-term secondary settlement or consolida-tion remains to take place.432 229. Estimated secondary settlement of the main portion of the auxiliary building and the control tower has been calcu-lated. Based on these estimated settlement values, differen-tial settlement between the control tower and main portion of the auxiliary building should not be more than 0.25 inches.

Secondary settlement of the electrical penetration areas should be dominated by the adjacent reactor buildings which could result in 0.2 inches of differential settlement between the south corners of the control tower and the south wall of the electrical penetration areas at a point on the centerline of the adjacent reactor projected south.433 230. The Applicant has taken into account the effects of differential settlement in evaluating the remedial soils mea-sures for the control tower, electrical penetration areas and FIVPs. The NRC Staff reviewed the Applicant's calculations and 431 For a detailed description of placement of jacks, loading of piers and final lock off of jacking loads, see Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxil-iary building, at pp. 20-28, 31, 36-37, following Tr. 5509; Burke, Tr. 5536-5566; see also SSER #2, 5 3.8.3.1, pp. 3-8 through 3-10.

432 Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building at pp. 53-55, following Tr.

5509.

433 Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building at pp. 55-77, following Tr.

5509.

-171-i I

I l found that the Applicant's evaluations are acceptable and that all the requirements of SRP section 3.8.4 have been met.434 231. The Applicant has taken into account loads which would be imposed by postulated seismic events in developing and j evaluating the design of the remedial soils measures for the 4 control tower, electrical penetration areas and FIVPs and, in so doing, has complied with the requirements of SRP sections 3.7.2, 3.8.3 and 3.8.5.435 In fact, several earlier designs were abandoned in favor of the underpinning the Applicant now l proposes, in large part because of the need to design for a larger earthquake than the FSAR SSE.436 ,

232. Because the SSRS was not yet agreed upon when the

design of the remedial soils measures was developed, the Appli-i cant used loads equal to 1.5 times the loads which would result from the SSE in evaluating the design of the remedial soils measures for the control tower, electrical penetration areas and the FIVPs. Subsequent analysis by a consultant hired by the Applicant and an audit of the Applicant's design calcula-i 434 Rinaldi, prepared testimony on Intervenors' Conten-

]

tions at p. 4, following Tr. 12080; ,see also Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary build-ing'at p. 47, following Tr. 5509; SSER #2, 5 3.8.3.1, at pp.

2-17, 2-23, 2-40 through 2-41; Johnson, Tr. 5682-5687; Kane, Tr. 12069-12070.

Rinaldi, prepared testimony on Intervenors' Conten-tions at pp. 6-8, following Tr. 12080; SSER #2, 6 3.8.3.1, at pp. 3-10 through 3-11; Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building at p. 46 and Appendix 13, following Tr. 5509.

436 Hood, Tr. 2744, 5467-5468; J. Cook, Tr. 18483-18484.

-172-tions by the NRC Staff have determined that loads equal to 1.5 times SSE loads are conservative in relation to loads which would result from the now agreed upon SSRS.437 233. The Applicant has analyzed the potential of seismic shakedown affecting the performance of Category I structures.

However, because the replacement fill under the FIVPs will be compacted to a 95% relative density and all of the underpinning will be founded on glacial till, as is the main portion of the auxiliary building, seismic shakedown is a factor only with respect to the railroad bay and liquid radwaste areas of the auxiliary building. The Applicant has evaluated the seismic shakedown effects for the railroad bay and liquid radwaste areas and determined that even in the event of an earthquake with peak ground acceleration of 0.199, settlement of no more than approximately 0.25 inches would occur. This amount of settlement would not affect the integrity of the auxiliary building.438 234. Applicant and the Corps of Engineers, for the NRC Staff, have conducted independent liquefaction analyses for the Midland site. Insofar as they apply to the auxiliary building and the FIVPs, these studies indicate that there is a poten-437 Kennedy, Tr. 6004-6028, 6038-6041 and Rinaldi, Tr.

12130-12131; Rinaldi, prepared testimony on Intervenors' Conten-tions at p. 7, following Tr. 12080. The Seismic Margin Review will analyze the entire auxiliary building using the SSRS. See SSER #2, 6 3.7.2.2, at pp. 3-2 through 3-4.

438 Shunmugavel, prepared testimony on auxiliary building seismic shakedown, following Tr. 11997 and Tr. 12004-12011; Woods, prepared testimony on Seismic Shakedown settlement at the Midland Site, Except DGB (hereinafter " prepared testimony on seismic shakedown"), at p.6, following Tr. 11547.

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-173-tial for liquefaction in the plant fill soils beneath the rail-road bay area of the auxiliary building. By lowering the ground-water elevation in this area below elevation 610, Applicant's permanent dewatering system will eliminate the potential for liquefaction. The natural soils beneath the auxiliary building are not liquefiable. Therefore the underpinning and excavation and backfill measures for the control tower, electrical pene-tration areas and FIVPs will elininate the potential for lique-faction in these areas. In carrying cut its liquefaction analy-sis the Corps of Engineers postulated a seismic event with peak ground acceleration of 0.199, unich is more severe than the earthquakes used to establish the SSRS.4 9 The Licensing Board concludes there is an acceptable margin cf safety against lique-faction, provided the groundwater in the railroad bay area is maintained below elevation 610.

235. During the course of the evidentiary hearings, Judge Harbcur expressed the following concerns with respect to the remedial soils measures:

1) that the system for detecting structure movement be reliable as well as accurate so that large data gaps do not occur or instru-ments get covered up with sand; 2) that the plan for arresting structural movement, if it should occur, is adequate; and 3) that there is sufficient clearance between the turbine building and the auxiliary building, after taking into account any settlement of the buildings, so that the two building 540 would not collide during an earthquake 439 SSER #2, S 2.5.4.5.5 at pp. 2-42 through 2-44; see also Woods, prepared testimony on liquefaction, following Tr.

9745.

440 Tr. 7122-7128.

-174-236. Because of the possibility of structural movement as a result of the excavations alongside and under existing struc-tures necessary for construction of the remedial soils measures for the control tower, electrical penetration area and FIVPs, the Applicant has installed extensive instrumentation to monitor any absolute or relative movement which does occur.441 237. The primary monitoring system consists of a network of state of the art electronic measuring devices which will be read by computer every hour and which will be attended by a technician 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> a day.442 At every point where an 4. loc-tronic device is installed there is also installed a mechanical gauge which does not depend on electricity to operate. The '

mechanical gauges will be used to cross-check the electronic readings and will serve as a backup system in the event of a power outage.443 All the instrumentation is installed away from the immediate area of any construction activities and all the measuring devices are in metal cases so they should not become covered with sand or suffer degradation due to environ-mental conditions.444 Together the mechanical and electronic l 441 For a detailed description of the instrumentation, places of installation and movements measured, see Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary build-ing, at pp. 29-34 and Figure Aux-36, following Tr. 5509; SSER l #2, S 2.5.4.6.1, at pp. 2-44 through 2-49; Krause, Tr. 9400-9405.

442 l Krause, Tr. 9400-9402.

443 Krause, Tr. 9404-9405.

444 Krause, Tr. 9405.

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-175-devices provide a reliable and accurate400 monitoring system for detecting any structural movement and provide reasonable assurance that no significant data gaps will occur.446 238. The Applicant and the NRC Staff have agreed on alert and actioa levels for structural movement447 which, if reached, require that appropriate procedures 448 be followed. The action i levels for the auxiliary building were arrived at by analyzing the structure to determine what would constitute tolerable deflections. Once these were calculated and the action levels 445 The instrumentation for monitoring movement of exist-ing structures is already fully in place and has been tested by the NRC etaff. The tests show that the instruments accurately ,

measure deflections within tolerable limits. R. . Cook, Landsman, Gardner and Shafer, prepared testimcny on Quality Assurance, at -

pp. 3-4 and Attachment No. 5 (inspection report) at p. 4, follow-ing Tr. 11391. .

446 Krause, Tr. 9404-9405; R. Cook, Landsman, Gardner and Shafer, prepared testimony on Quality Assurance at pp. 3-4, following Tr. 11391; Landsman and Kane, Tr. 11397-11402. Also, it should be noted that there are several other backup monitor-ing systems. Extensometers have been installed to monitor any strains certain walls might have imposed on them and a crack monitoring program has been implemented which will monitor the t

development of any new cracks or any change in the width of existing ones. Burke, Tr. 5521-5526; Shunmugavel, Tr. 9413-9414 and Boos, Burke and Shunmugavel, Tr. 9549-9550.

447 The alert and action levels for displacement of the auxiliary building during the different phases of construction of the underpinning are set out in SSER #2, Staff Ex. 14, at p.

2-49, Table 2.7. The only alert and action levels set for the auxiliary building are for displacement and crack monitoring, though strain monitoring instrumentation will be used as a l

back-up system. Shunmugavel, Tr. 9416.

458 The precedures to be followed are set out in Bechtel Specification C-7 00. See Boos, Tr. 9408-9412. See also Landsman, .

Tr. 11392-11396. Bechtel Specification C-200 was entered into 4

evidence as Attachment No. 2 to the prepared testimony of R.

i Cook, Landsman, Gardner and Shafer on Quality Assurance, follow -

ing Tr. 11391.

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-176-were set, with the concurrence of the NRC Staff, half the action level would generally be used as the alert level. The action levels for deflection of the auxiliary building are based on a very conservative analysis of what that structure could tolerate.449 239. The computer which takes hourly readings of all the instruments monitoring structural movement is set to sound an alarm and immediately print out the data it has collected if an alert or action level is reached.450 In the event an action level is reached the NRC Staff will be notified.451 240. Any movement the monitoring system detects will be analyzed and appropriate steps will be uncertaken in response to that movement.452 The primary method which would be used to arrest structural movement would be to jr.ck additional loeds into the existing piers and underpinning.453 However, there are contingency plans for installing additional tea.porary supports 449 Shunmugavel, Tr. 9413-9414.

450 Krause, Tr. 9400-9404. An NRC Staff test verified

! that the computer did in fact sound an alarm and print out data when displacement exceeding the alert level was recorded by one of the instruments. R. Cook, Landsman, Gardner and Shafer, prepared testimony on Quality Assurance at pp. 3-4, following Tr. 11391; Landsman, Tr. 11397.

451 Boos, Tr. 9412.

452 In response to any movement trends which suggest that an alert or action level might be reached, steps will be taken to arrest the movement before an alert or action level is reached.

Kane and Poulas, Tr. 9634-9641. For a discussion of procedures, see Krause, Burke and Boos, Tr. 9402-9412 and Landsman, Tr.

11392-11399.

453 Analysis has determined that the jacks and the piers have the capacity to take additional loads. Burke, Tr. 9406.

-177-in those instances when the jacking could not be relied upon.455 If appropriate, all work would be stopped in the area of the movement.455 241. The Applicant has performed an analysis of how much space is needed between the turbine building and the auxiliary building at various elevations in order to insure that these buildings do not come in contact with each other during an earthquake. Calculations of the maximum amount of deflection of each of these buildings during an earthquake determined that at all elevaticns there is significantly more space available between the buildings than the combined amount of deflection of both buildings.456 For ex ample, adding the maximum daflections during an earthquake equal to the FSAR SSE of the turbine build-ing and the auxiliary building at elevation 695, the total movement is 2.84 inches conpared to an existing 8-inch space.457 At elevation 659 the total deflection is .9 inches compared to 454 The temporary supports will be on-site and can be

installed in a short amount of time if that becomes necessary.

l Burke, Tr. 9407-9408.

l 455 For general discussion of steps that might be taken l

in response to structural movement, see Burke and Boos, Tr.

9406-9412, 9484-9492 and Poulas, Tr. 9635-9636.

456 This analysis was performed using the FSAR SSE; how-ever, calculations show that the structures' response would be virtually the same for the SSRS and so the conclusion is valid even when the larger earthquake is taken into account. Shunmugavel, Tr. 9416-9420 and Rinaldi, Tr. 9626-9629.

l 457 The eight-inch figure includes space occupied by a flexible grille which extends out from the turbine building but which would collapse upon contact with the auxiliary building.

Shunmugavel, Tr. 9417-9418 and Rinaldi, Tr. 9608-9623; see also Applicant's Ex. 27.

-178-an existing 2-inch space.458 There is reasonable assurance, therefore, that the turbine building and the auxiliary building will not interact during a seismic event.459 242. The Licensing Board concludes that, contrary to Inter-venor Stamiris's Amended Contention 4(c)(a), the Applicant has adequately and conservatively taken into account the dynamic responses of the control tower, electrical penetration areas and FIVPs with regard to dewatering effects, differential soil settlement and seismic effects in the design and evaluation of those remedial soils measures.

243. The Licensing Scard concludee that the Applicant has .

complied with all applicable requirements in designing the

remedial soils measures for the control tower, electrical pene-tration areas and FIVPs. The design is conservative with re-apact to the loads it is cypected to encounter or withstand.

The design provides reasonable assurenec that when completed the remedial soils measures will provide an adequate and stable 458 For a general discussion of the calculations and description of the structures' responses and available space, see Shunmugavel, Tr. 9416-9428 and Rinaldi, Tr. 9626-9630, and Applicant's Ex. 27; see also SSER #2, 6 3.7.2.4, at p. 3-5. In addition it would be possible to gain additional space at eleva-tion 659 by chipping away a protruding floor slab, though there is little likelihood this ever need be done. Shunmugavel, Tr.

9420-9421 and Rinaldi, Tr. 9627-9630.

459 Shunmugavel, Tr. 9416-9428 and Rinaldi, Tr. 9626-9630; SSER #2, 6 3.7.2.4, at pp. 3-4 through 3-5. As a safeguard to insure that any settlement of the auxiliary building or the turbine building during underpinning activities does not reduce the existing spaces between the buildings to a point where two buildings might interact, the Applicant has installed instru-mentation to monitor any horizontal displacement of these build-ings at elevation 695. Shunmugavel, Tr. 9421-9422.

-179-foundation for the control tower, electrical penetration areas and FIVPs.460 244. Our conclusions are necessarily subject to satisfac-tory completion of the proposed remedial measures for the auxil-iary building and FIVPs. In our Partial Initial Decision on Quality Assurance and Management Attitude Issues we address whether Applicant's construction and quality assurance practices, including the independent overview being performed by Stone &

Webster, and the NRC Staff's oversight, are adequate to ensure that the remedial work can be successfully carried out.

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460 Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building at pp. 57-59, following Tr.

5509; SSER #2, 5 2.5.4.4.1, at p. 2-23.

-180-SERVICE WATER PUMP STRUCTURE 245. The service water pump structure (SWPS) is a Seismic Category I structure, located at the northwest bank of the return leg of the cooling pond, adjacent to the circulating water intake structure (CWIS) and the Seismic Category I retain-ing wall of the cooling pond. The SWPS houses the five pumps and support equipment for the service water system.461 246. The SWPS is a rectangular, reinforced concrete build-ing with upper and lower sections of different dimensions. The lower section is approximately 72 feet long and 85 feet wide.

Its base slab is supported on undicturbed glacial till at eleva-tion 597. The upper section is 106 feet long and 86 feet wide.

This size difference results in an overhang at the north end of the upper section. The base slab of this overhang portion of the SWPS is supported by a triangular wedge of soil backfill at elevation 617.462 247. To evaluate the backfill under the overhang portion of the SWPS, eleven soil borings were taken in the vicinity of the SWPS. Two borings were taken inside the building and nine in the surrounding area. These borings indicated that some 461 Testimony of Alan Boos, Edmund M. Burke, James P.

Gould and Palanichamy Shunmugavel concerning Midland Plant Service Water Structure (hereinafter " Boos, Burkey, Gould and Shunmugavel, prepared testimony on SWPS"), at pp. 1-3 and Figures SWP-1, SWP-2, SWP-3 and SWP-4, following Tr. 9490; Hood, Tr. 9728-9729; SER, 51.12.7, p. 1-23.

462 Boos, Burke, Gould and Shunmugavel, prepared testimony on SWPS at pp. 1-3, following Tr. 9490. For a description and discussion of the triangular wedge of backfill see Boos, Tr.

9536-9541 and Applicant's Ex. 28.

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-181-localized areas of the soil backfill underneath and adjacent to the overhang portion of the SWPS had not been sufficiently compacted.463 248. As in the case of the auxiliary building, the inade-quately compacted fill revealed by borings has not caused the SWPS to undergo any unusual settlement, or to experience any significant structural distress. A Foundation Data Survey Program was established by the Applicant in May, 1977 to monitor settlement of Seismic Category I buildings. Pursuant to this program settlement markers were attached to the four corners of the SWPS by the summer of 3 973. In addi?. ion, six construction survey control points were installed a short time after concrete placement. Monitoring of the settlement markers and the survey control points has shown that the SWPS has been very stable with a maximum north-south differential settlement of 0.25 inches.464 249. In December, 1978 a crack mapping program was insti-l tuted for all Seismic Category I buildings founded on plant fi31.465 Several crack mappings of the SWPS have been conducted ,

pursuant to this program. An analysis of the cracks observed in the SWPS was undertaken by Applicant's expert, Dr. Corley, who determined that the primary reason for the cracking was 1

463 Boos, Burke, Gould and Shunmugavel, prepared testimony on SWPS at pp. 3-5, following Tr. 9490.

464 Boos, Burke Gould and Shunmugavel, prepared testimony on SWPS at pp. 3-5, following Tr. 9490; Boos, Tr. 9517-9518; l

j SSER #2, 52.5.4.5.2, p. 2-41.

465 Burke, Corley, Gould, Johnson and Sozen, prepared testimony on auxiliary building at p. 11, following Tr. 5509.

-182-restrained volume changes that occur during curing and drying of concrete. Although the possibility can not be completely ruled out that stresses due to differential settlement contrib-uted to some degree to the observed cracking, the observed crack patterns do not support the conclusion that stress due to differential settlement was a primary cause of cracking. No evidence of structural distress was observed.466 250. While the observed settlement of the SWPS and an analysis of the observed cracks in the SWPS indicate that the SWPS has not suffered significant structural distress to date,467 the Applic4nt has chosen to underpin the overhang portion of the SWPS ir order to ensure long-term foundation stability and to allay concerns about future dif ferential settlement due to the pockets of compressible backfill dis-covered under tha ovarhang portion of the SWPS.4 251. The underpinning for the SWPS will consist of a con-tinuous perimeter underpinning wall beneath the north end of the SWPS. The reinforced concrete wall will form a box struc-ture beneath the overhang, connected to the sides of the lower portion of the existing structure, and extending from the upper 466 Testimony of Dr. W. Gene Corley Concerning Cracking in the Service Water Pump Structure, following Tr. 11206; SSER

2, 52.5.4.4.1, p. 2-23.

467 Rinaldi, Tr. 9721.

468 Boos, Burke, Gould and Shunmugavel, prepared testimony on SWPS at p. 6, following Tr. 9490; SSER #2, 52.5.4.4.1 at p.

2-23. Applicant initially considered a system of piles and cor-bels as the remedial m6asure for the SWPS, but abandoned this approach when the NRC Staff recommended increased seismic review criteria for the Midland site. See J. Cook, Tr. 18483-18484; Hood, Tr. 2743-2746; Holt Ex. 3.

-183-foundation slab to undisturbed glacial till at approximately elevation 587. The completed underpinning wall will thus provide a structural foundation resting on undisturbed glacial till.469 252. In order to construct the underpinning for the SWPS an access cofferdam will be constructed to provide access for workers and equipment. The access cofferdam will be excavated in two stages. Initially, it will be excavated, adjacent to the SWPS, to elevation 618 to permit installation through approach pits of the initial underpinning piers at the northwest and north-east corners of the SWPS. When this initial underpinning is com-pleted the access cofferdam will be lowered locally at the north-west corner to elevation 609 to provide access for escavation of a tunnel beneath the west wall of the SWPS. A tunnel munt be used to provide access for constructing the west underpinning wall be-cause of the location of the CWIS. All of the underpinning under the north and east walls of the SWPS will be constructed from ele-vation 618 by means of approach pits from the access cofferdam.470 253. The access cofferdam will be constructed using soldier piles, tubular steel lagging and wales in order to ensure proper support for the adjacent soil.471 254. In order to construct the underpinning it will be necessary to temporarily lower the groundwater table in the 469 Boos, Burke, Gould and Shunmugavel, prepared testimony on SWPS at pp. 6-7, following Tr. 9490; SSER #2, $3.8.3.2 at

p. 3-15.

470 Boos, Burke, Gould and Shumugavel, prepared testimony on SWPS at pp. 8-9, following Tr. 9490.

471 For an explanation of the terms " soldier piles,"

" lagging," and " wales," see Burke, Tr. 5534-5536 (auxiliary building testimony).

-184-area of the SWPS. Construction dewatering wells will be installed in the vicinity of the SWPS for this purpose. Operation of the construction dewatering wells will maintain the groundwater level two feet below the lowest point of any existing excavation during the construction of the underpinn'ng for the SWPS.472 255. To offset any loss of buoyancy force during the con-struction due to temporary dewatering, post-tensioning ties were inatalled along the tops of the east and west exterior walls of the SWPS in November, 1981, 'inese ties, which consist of two tendon groups on each side of the building, apply a compressiva force af apprcximately 500 kips to the upper por-tion of the east and west exterior wall =;.473

256. The construction of the underpirining will progress an stages. The principal consideration in the first stage of construction is to provide initial support for the north end of the SWPS In order to compensate for the possible loss of sup-port under the base slab caused by the underpinning operations and to further counteract any loss of buoyancy force. After the first stage is completed the rest of the piers will be constructed in a designated sequence.474 472 Boos, Burke, Gould and Shumugavel, prepared testimony on SWPS at pp. 8, 10, following Tr. 9490; SSER #2, 52.5.4.6.1.2 at p. 2-51.

473 Boos, Burke, Gould and Shumugavel, prepared testimony on SWPS at p. 8, following Tr. 9490. See also Shunmugavel, Tr.

9515-9517. -

474 For a detailed description of the construction proce-dures and the sequence which will be employed in constructing the underpinning, see Boos, Burke, Gould and Shunmugavel, pre-pared testimony on SWPS at pp. 9-15 and Figs. SWP-11 through SWP-13, following Tr. 9490; SSER #2, Fig. 2.9, pp. 2-27 to 2-30.

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-185-257. A typical pier is 5 feet long, 4 feet wide and 30 feet deep. The piers along the north wall will be belled to 6 feet wide at the bottom.475 Shear keys and reinforcement will be used so that the individual piers, though cast separately, will form one continuous wall upon completion.476 258. Each pier will be founded on undisturbed natural soil which will have been inspected and accepted as adequate by a geotechnical engineer before the pier is cast. A lean concrete werking mat will be east on top of the inspected and acctmced soil to ensure it ren ains undisturbed throughout the casting of the pier.477 259. Intervenor Barbara Stamiric han crpressed ce?tain safety-related concerns with respect to the remedial :casures the Applicant has proposed for insuring adequate foundation conditions for the SWPS in her centention 4(C) which states, as amended:

475 Boos, Burke, Gould and Shunmugavel, prepared testimony on SWPS at p. 10, following Tr. 9490.

476 Boos, Burke, Gould and Shunmugavel, prepared testimony on SWPS at p. 15, following Tr. 9490.

477 It is expected that all the piers will be founded on undisturbed glacial till; however, it is possible that some pockets of alluvial sand may be encountered at the 587' eleva-tion. If alluvial sand is encountered at the base of any of the piers, it will be removed if the pocket is shallow (less than 18 inches deep); however, if it is deep, it shall be ac-cepted as an adequate foundation material if it is undisturbed.

The alluvial sand found so far has exhibited higher blow counts than the undisturbed glacial till and therefore would provide an adequate foundation. Boos, Burke, Gould and Shunmugavel, prepared testimony on SWPS at pp. 11, 29-32, following Tr. 9490. If any excavation of shallow pockets of alluvial sand takes place next to an existing pier and extends more than 6 inches below that pier, sheeting will be placed to support the soil underneath the pier. Burke, Tr. 9545-9547.

-186-Remedial soil settlement actions are not based on adequate evaluation of dynamic responses regarding dewatering effects, differential soil settlement and seismic effects for these structures:

(b) Service Water Intakg7guilding (sic]

and its Retaining Walls 260. The seismic Category I retaining wall in the vicinity of the SWPS is structurally isolated from the SWPS &nd is there-fore not affected by the underpinning of the overhang portion of the SWPS. The retaining wall was constructed in two sections i which are structurally isolated from one another (thaugh the sections perform as a unit) . One section is totalJy founded en

undisturbed glacial till and the other is totally founded on plant fill. The retaining wall has exhibited only very small settlement to date and no compressible layers of soil were found in the plant fill supporting the one sectier: of the re-taining wall. Therefore, it was determined that no remedial soils measures needed to be undertaken with respect to the retaining wall. Moreover, because the two sections are struc-turally isolated from one another, even if the two sections l

settled different amounts no structural distress would result in either section.479 478 Intervenor Barbara Stamiris's Answers to Applicant's Interrogatories and Amendment to Contentions, filed April 20, 1981, at p. 12. It is apparent that Mrs. Stamiris's contention j'

refers to the service water pump structure, rather than to the adjacent circulating water intake structure, which is not safety related. See Tr. 9500, 9517-9521.

Kane, Tr. 9692, 9723-9727.

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-187-261. The Applicant has taken into account the load result-ing from the lowest groundwater level possible as a result of the temporary dewatering necessary for the construction of the underpinning for the SWPS in evaluating the design of that underpinning. In addition, the Applicant has taken into account the highest possible water elevation (the highest water eleva-tion in the cooling pond) in evaluating the design for the underpinning of the SWPS. The NRC Staff reviewed the calcula-tions the Applicant used to analyze the design in light of the loads which would result from the lowest and highest possible groundwater levels and found that the design v.is acceptable and met all applicable requirements with regard to its capacity to withstand those loads.480 262. The Applicant has predicted that after completion of the underpinning there should be no more than 0.1 to 0.2 inches of differential settlement between the overhang portion of the SWPS and the portion currently founded on glacial till.401 The NRC Staff considers this estimate of differential settlement to be reasonable and acceptable. Moreover, the NRC Staff has 480 Rinaldi, Tr. 9697-9699; Boos, Burke, Gould and

[ Shunmugavel, prepared testimony on SWPS at pp. 24-25, following Tr. 9490; Gould, Tr. 9532-9534.

481 Boos, Burke, Gould and Shunmugavel, prepared testimony l on SWPS at pp. 36-37, following Tr. 9490; Kane, Tr. 9690-9691; l SSER #2, $2.5.4.5.2 at p. 2-41. Predicted differential settle-

! ment is small because, before final lockoff, loads will be jacked into the underpinning until only secondary settlement remains to occur. In addition, the Applicant considered any additional differential settlement which might result during construction as a result of temporary dewatering by assuming an additional l 0.1 inches of differential settlement. Boos, Burke, Gould and Shunmugavel, prepared testimony on SWPS at pp. 24, 26, 34-36, 39, following Tr. 9490; SSER #2, s3.8.3.2 at p. 3-15.

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determined that the Applicant considered loads associated with both the predicted differential settlement and the predicted :

total settlement in analyzing the design of the underpinning for the SWPS. The Applicant assigned a load factor of 1.4 (equivalent to the load factor for dead weight loads) to differ-ential settlement loads in accordance with the requirements of the SRP. The NRC Staff has reviewed the Applicant's calculations and fcund them to be acceptsble and that the Applicant's design for the SWPS' underpinning to be conservative with respect to its capacity to withstand any loads which would be imposed as a result of predicted differential settlement.482 263. In addition, the App 12 cent has installed instrumenta--

tion in the underpinning itself and in the SWPS in order to monitor any building movement which might occur prior to or during construction in order to determine if the SWPS is suffer-ing any structural distress as a reralt of the underpinning operation. A crack monitoring program has also been established toward the same purpose.483 482 SSER #2, 52.5.4.5.2 at p. 2-41; Kane, Tr. 9690-9691; Rinaldi, Tr. 9697-9698.

483 For a detailed discussion of the instrumentation and l acceptance criteria for structural movement and cracking during I

construction, see Boos, Burke, Gould and Shunmugavel, prepared testimony on SWPS at pp. 15-20, following Tr. 9490; Shunmugavel, Burke and Boos, Tr. 9491-9492, 9547-9550, 9570-9574, 9582-9583; SSER #2, 52.5.4.6.1.2 at pp. 2-50 and 2-51; Poulos, Tr. 9597-9599, 9630-9634, 9637-9638. These acceptance criteria have been incorporated into Applicant's construction specifications as

" alert" and " action" limits, each with specified consequences.

Efforts have been made to anticipate and plan for contingencies which might cause structural movement or cracking. The intent is to detect such situations and take corrective actions before the action limits are exceeded. See Boos and Burke, Tr. 9550-9555; Boos, Tr. 9583-9593; Poulos, Tr. 9634-9637, 9641.

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-189-264. The Applicant has taken into account seismic effects in evaluating its design of the underpinning for the SWPS. The underpinning for the SWPS is required to be designed to meet loads associated with the SSRS; however, because the SSRS had not been agreed upon when the design was developed, the Appli-cant used loads equal to 1.5 times SSE loads in developing and evaluating the design. Subsequent analysis has determined that loads eq;al to 1.5 times SSE loads exceed those which would result frem the now agreed upon SSRS. The NRC Staff has re-viewed the Applicant's design calculations and is satisfied that the underpinning for SWPS will be adequate to meet design conditians, incJuding an earthquake equal to the SSR3.404 .

255. Because once the underpinning for the overhang portion of the SWPS is complete the entire SWPS will be founded on undisturbed glacial till, liquefaction and seismic shakedown are not factors which will effect the performance of the SWPS during a seismic event.485 266. The Applicant has also analyzed the possibility of an interaction between the SWPS and the nearby CWIS during postu-lated seismic events. The results of this analysis show that 484 SSER #2, 63.8.3.2 at pp. 3-14 to 3-15; Rinaldi, Tr.

9694-9697, 9713-9718; Boos, Burke, Gould and Shunmugavel, pre-pared testimony on SWPS at pp. 20-21, 25, following Tr. 9490.

The entire SWPS, existing portion plus underpinning, will be evaluated to determine whether the integrity of the structure will be affected by an earthquake equal to the SSRS as part of the Seismic Margin Review. Preliminary indications are that the entire SWPS could withstand an SSRS earthquake without im-pairing safety-related functions. Rinaldi, Tr. 9713-9719; SSER #2, 53.7.2, at pp. 3-2 to 3-4.

485 Kane, Tr. 9730-9734; SSER #2, $2.5.4.5.5 at pp. 2-42 to 2-44. See generally paragraphs 422 et seq., infra. ,

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-190-there is sufficient space between the two buildings to ensure they will not collide duridg an earthquake equal to the SSRS.

The space available between the SWPS and the CWIS is 1 inch, while the sum of the maximum displacements of the two buildings during a postulated FSAR SSE is 0.3 inches and during a postu-lated SME is 0.5 inches.486 267. The Licensing Board concludes that contary to Inter-venor Stamiris' Amended Contention 4(C)(b), the Applicant has adequately taken into account the dynamic responses of the remedial soils measures for the SWPS with regard to dewatering effects, differential soil settlement and seismic effects in the design and evaluation of those remedial soils measures. -

Further, the Board concludes that the Seismic Category I re-taining wall, to which Contention 4(C)(b) apparently also refers, is not affected by remedial soils measures taken with respect to the SWPS, nor are any remedial soils measures necessary with respect to it.

268. The Licensing Board concludes that the Applicant has complied with all applicable requirements in designing the underpinning for the SWPS. The design is conservative with respect to the loads it is expected to encounter and withstand and provides reasonable assurance that when completed as designed the underpinning will provide an adequate and stable foundation for the overhang portion of the SWPS.

486 SSER #2, 53.7.2.4 at pp. 3-4 to 3-5; Shunmugavel, Tr.

9575-9579; Rinaldi, Tr. 9606-9608. See also Gould, Tr. 9532-9534.

The NRC Staff intends to confirm these conclusions as part of the Seismic Margin Review. Rinaldi, Tr. 9626-9630.

-191-269. The Licensing Board's conclusions are subject to the satisfactory completion of the remedial measures for the SWPS.

In our Partial Initial Decision on Quality Assurance and Manage-ment Attitude Issues we address the issue of whether Applicant's construction and quality assurance practices, including the independent everview being performed by Stone and Webster, and the NRC Staff's oversight, are sufficient to ensure that this remedial work will be successfully carried out.

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-192-BORATED WATER STORAGE TANKS 270. Each unit of the Midland Nuclear Power Plant complex has a 500,000 gallon, stainless steel borated water storage tank ("BWST"). The two tanks are located in the tank farm area on the north side of the containment and auxiliary buildings.

The tanks are 32 feet high and 52 feet in diameter. Valve pit structures are connected to the southeast side of each BWST to provide access to the piping connection to the tank and house the fill and drainline valves.487 271. The function of the BWSTs is to supply borated water to the reactor building spray system and emergency core cooling system during the injection phase following a loss-of-coolant accident. As such they are essential to the safe emergency shutdown of the plant. Therefore, they are designated as Seismic Category 1 structures.488 272. Each BWST is a cylindrical structure with a flexible, flat bottom. The tank shell, roof, and part of the water in the tank are supported by a reinforced concrete ring wall.

487 Hendron, prepared testimony on BWST foundations at p.

5 and Figure 1, following Tr. 7186; Testimony of Alan J. Boos and Dr. Robert D. Hanson on behalf of the Applicant Regarding Remedial Measures for the Midland Plant Borated Water Storage Tank (hereinafter " Boos and Hanson") at pp. 1-2 and Figures BWST-1 and BWST-2, following Tr. 7173. See also Testimony of Darl Hood, Hari Narain Singh, and Joseph Kane concerning the Remedial Measures for the Borated Water Storage Tanks (herein-after " Hood, Singh and Kane") at p. 6, following Tr. 7444; SSER #2, 6 3.8.3.3 at p. 3-16,.

488 Boos and Hanson, prepared testimony at p. 10, follow-ing Tr. 7173; see also Hood, Singh and Kane, prepared testimony at p. 4, following Tr. 7444.

-193-Compacted granular fill lies inside the ring wall with a 6 inch layer of oiled sand separating the tank bottom from the granular fill. There is a 1/2 inch thick asphalt impregnated fiberboard (Celotex) between the tank bottom and the ring wall. The material is compressible and tends to distribute the tank wall loading to the ring wall in a more uniform manner than if there were no compressible material at the interface. Approximately 25 feet of compacted fill lies under the foundation structure.

The flexible tank bottom enables the vertical pressure created by the weight of the water to transfer directly to the soil within the ring wall. This vertical pressure also causes a lateral pressure in the sand which is resisted by the ring wall. Anchorage for resisting overturning loads caused by externally applied lateral forces is provided by forty 1-1/2 inch diameter anchor bolts which attach the tank to the ring foundation.489 273. Exploratory programs were conducted on the natural soilsHat the Midland site in 1968, 1969 and 1970. Additional borings, test pits and plate load tests were performed in the area of the BWSTs during 1978 and 1979 after compacted fill materials had been placed. Plant grade around the BWST is l approximately at elevation 634. From that elevation down to between 595 and 605 the foundation material is compacted back l

489 Boos and Hanson, prepared testimony at pp. 1-2, following Tr. 7173; Testimony of Robert P. Kennedy,and Robert D.

Campbell (hereinafter, " Kennedy and Campbell") at p. 2 and Attachment B, p. 1-3, following Tr. 7345; Kennedy, Tr. 7382-7384; l Boos, Tr. 7954-7956; SSER #2, 9 3.8.3.3 at p. 3-16.

(

I i

-194-fill. Below elevation 595 to 605 the natural materials are reported as either glacial or overconsolidated lacustrine clay.

In some locations natural sands are found with blow counts ranging between 50 to 100 blows per foot.490 There appears to have been an area of less stiff backfill material in the south-west side of the Unit 1 BWST.491 274. The foundations for the two BWSTs were constructed between July, 1978, and January, 1979. Erection of the tanks was completed by December, 1979. In October, 1980, Applicant filled both tanks with water and by means of surveys compiled since September, 1978, proceeded to monitor the behavior of the foundations and fill materials.492 ,

275. On January 29, 1981, pursuant to 10 CFR 50.55(e),

Applicant reported a deficiency of the tank foundation to the NRC 493 upon discovery of differential settlement between the valve pit and the ring wall foundation.494 Discovery occurred when structural analysis indicated that the allowable moment capacity for the dead load and the differential settlement 490 Hendron, prepared testimony on BWST foundations at pp. 6-7 and Figure 3, following Tr. 7186.

491 Boos, Tr. 7939-7947, Applicant's Ex. 25.

492 Booz and Hanson, prepared testimony at p. 1, follow-ing Tr. 7173; Hendron, prepared testimony on ewsT foundations at

p. 6, following Tr. 7186. Compare Hood, Tr. 1130-1131, 1147-1148, 1152-1153 with Hood, Singh and Kane, prepared testimony at p. 9, following Tr. 7444.

493 Boos and Hanson, prepared testimony at p. 1, follow-ing Tr. 7186.

494 Hendron, prepared testimony on BWST foundations at

p. 6, following Tr. 7186.

i

-195-condition was exceeded in several locations in the foundation structure.495 Examination at the locations where overstresses were calculated revealed visible cracking in both the Unit 1 and Unit 2 foundations at the juncture of the tanks and the valve pit structures.496 276. The witnesses which appeared before the Board varied slightly in their interpretations of what caused the BWST problem. Mr. Boos and Dr. Hanson testified that originally the reinforced concrete BWST foundations were designed to include the load of two small tanks to be located on the top slab of each valve pit. Later, when these small tanks were relocated to another area of the plant, the original design of the BWST foundations was not modified. When each BWST was loaded with water, the weight of the water acted directly on the soil through the tank bottom, causing greater settlement beneath the tank bottom and ring foundations than beneath the valve pit.

Because of this uneven settlement, the valve pit rotated rela-tive to the ring walls and induced bending moments which had not been considered'in the original design.497 Mr. Boos believed that even if the tanks had been left on the valve pits, differ-ential settlement of reduced magnitude would have occurred, due 495 Boos and Hanson, prepared testimony at p. 3, follow-ing Tr. 7173.

496 The largest crack in the Unit 1 tank foundation was

.063" in width, and the largest crack in the Unit 2 tank founda-tion was .035." Hood, Singh, and Kane, prepared testimony at pp. 6-9, Figure 1 and Attachment 8, following Tr. 7444.

497 Boos and Hanson, prepared testimony at p. 3, follow-ing Tr. 7186.

i

-196-to the larger bearing area of the valve pits compared to the rest of the BWST foundation. Thus Mr. Boos and Dr. Hanson attributed the differential settlement at the BWSTs to errors in designing the foundations, rather than to soils properties in the vicinity.498 277. Dr. Hendron similarly was of the opinion that the primary settlements observed for the BWST (about 1.3 inches at the edge of the foundations) were not excessive, and that the structural cracks at the boundary between the valve pit and the ring wall indicated that the foundations were not really designed to take the distortions that they would get due to the fact that the valve pits were very lightly loaded and the ring walls were more heavily loaded.499 278. In Dr. Kennedy's judgment, there were three causes of the cracking of the ring wall. First, from the settlement patterns, he believed the soils under the west end of the Unit 1 BWST had a pocket of somewhat softer material than under the east side of the tank or under the Unit 2 BWST. The second cause was the valve pit, which had low bearing pressures and therefore to some extent acted like a snowshoe on snow. The valve pits did not push down as much as the rest of the founda-tions and this resulted in the largest stresses and the largest i

498 Boos, Tr. 7260-63. In response to a question from Judge Harbour, Mr. Boos subsequently conceded that there was an area of less stiff soil in the vicinity of the Unit 1 BWST.

However, he did not believe that there had been any uneven settlement or " rocking" of the Unit 1 BWST attributable to this less stiff area. Boos, Tr. 7939-43; Applicant's Ex. 25.

499 Hendron, Tr. 7215. Mr. Boos agreed with this evalua-l tion. Tr. 7216.

-197-cracking in the vicinity of the valve pit. The third and in Dr. Kennedy's view the major cause was the under-reinforcing of the ring wall. Had there been sufficient reinforcing steel in the ring wall, the load would have been spread to stiffer soil and the differential settlement would not have occurred.500 279. The NRC Staff witness, Mr. Kane, believed that the settlement that was experienced at the Unit 1 BWST was greater than he would have anticipated if the soil had been properly compacted, and therefore in his opinion inadequately compacted fill did contribute to the problem for the Unit 1 BWST.

The witness from the Corps of Engineers, Mr. Singh, while not disagreeing with Mr. Kane, also testified that the unsymmetrical foundation design was a factor in creating the observed differen-tial settlement.502 More than a year after the evidentiary hearing on the BWST were concluded, Dr. Ross Landsman, a soils specialist employed by the NRC's office of Inspection and Enforcement, Region III, volunteered his personal opinion that the unsymmetrical BWST foundation design was a design deficiency.

Dr. Landsman was under the mistaken impressicn that this issue had not previously been addressed in the hearings.503 280. Applicant and the NRC Staff agree on the remedy for the BWST foundation problcm. Applicant has proposed a three-500 Kennedy, Tr. 7367.

501 Kane, Tr. 7451; 7494-7515, 7516-17. See also SSER

2, $ 2.5.4.4.3 at p. 2-34; Hood, Tr. 1135-1136, 1149-1151.

02 Singh, Tr. 7481-7482.

503 Landsman, Tr. 16581-16591.

-198-phase corrective action consisting of (a) surcharging the valve pit and its surrounding area to reduce the residual differen-tial settlement on the foundation; (b) constructing a rein-forced ring beam around the periphery of the existing cracked beam; and (c) establishing a program for releveling the Unit 1 BWST.504 281. Applicant has already taken steps in furtherance of these remedial measures. The BWST valve pit surcharge opera-tion was performed and successfully completed by February, 1982. The process served to consolidate the fill beneath the valve pit, thereby reducing the residual differential settle-ment over the 40 year life of the plant. Further, it had the additional effect of reducing ring wall distortion. A monitor-ing program was in place to monitor foundation settlement, concrete cracks and strain in the tanks during surcharge place-ment and removal. This monitoring did not reveal any unexpected changes or abnormal results.505 504 Boos and Hanson, prepared testimony at pp. 4-10 following Tr. 7173; Hood, Singh and Kane, prepared testimony at pp. 13-18, following Tr. 7444, Tr. 7447-7449; Rinaldi and Matra, prepared testimony on BWSTs, etc., at p. 9, following Tr. 7537; Rinaldi, Tr. 7538-7545. Mr. Rinaldi's approval of the proposed remedial measures was made subject to a number of confirmatory items, as discussed in paragraph 285, infra. See also Landsman, Tr. 16590-16591.

505 Boos and Hanson, prepared testimony at pp. 4-7, Figure BWST-2 and Table 1; following Tr. 7173; Boos, Tr. 7223; SSER #2, f 2.5.4.4.3, at p. 2-34. But see Boos, Tr. pp. 7189-7190, 7271. After application of the surcharge, Applicant noted a 5-mil crack in the valve pit wall which extended to the bottom of the roof slab of the valve pit. At the point where (Footnote 505 continued on page 199)

1

-199-282. A new ring beam, constructed of reinforced concrete with a minimum compressing strength of 4,000 psi, is to be added to each BWST foundation. The modified beams are designed to resist all imposed loading from the tank including future bending induced by the predicted residual differential settle-ment between the ring wall and the valve pit described in para-graph 283, below. Shear connectors will transfer the shear force from the existing ring wall to the newly constructed ring beam.506 Although the stiffness of the existing ring wall has been taken into account in the design of the remedial measures, no credit has been taken for any strength in the existing wall.507 Never-theless, all cracks found in the existing ring exceeding 10 mils will be repaired with compressive grout to avoid potential cor-rosion damage to the reinforcing steel in the existing ring.508 (Footnote 505 continued from page 198) the crack touched the slab it was only one or two mils. Appli-cant was unable to determine whether the crack occurred prior to, or as a result of the surcharge. Boos, Tr. 7284-7286.

However, since the crack underwent no change subsequent to its discovery, and due to its small magnitude it was deemed by Applicant to be of no concern. Boos, Tr. 7286-7290. NRC Staff witness, Darl Hood, felt there was a "very high probability" that the Staff would have concurred with that finding. However, given the fact that a commitment had been made by Applicant to inform the Staff of relating to the propagation of cracks related to surcharging, he felt the crack should have been reported to the Staff. Hood, Tr. 7463-6746; and Hood, Singh and Kane, prepared testimony at Attachment 10, following Tr. 7444.

506 Boos and Hanson, prepared testimony at pp. 7-8, 12 and Figures BWST-4 and BWST-5, following Tr. 7173.

507 Boos and Hanson, prepared testimony at pp. 7, 14, following Tr. 7173; Hanson, Tr. 7253-54.

508 Boos and Hanson, prepared testimony at pp. 7-8, following Tr. 7173; Rinaldi, Tr. 7548.

r-.-p 7 ,g,y v-, - - - -m,. y - - - - -- - - - - -

-200- l l

283. Future settlement predictions used in designing the '

new ring beams were based on the data obtained from the full- i scale load test of the existing foundation and soil, by extra-polating the settlement versus log-time curve for each settle-ment marker. Basing settlement predictions on the full-scale I load test of the existing foundation is conservative because the modified BWST foundations will be stiffer and thus reduce future differential settlement.509 Moreover, the design proce-dure is conservative because no credit was taken for the sub-stantial reduction in future differential settlement which will be caused by the surcharge of the valve pits.510 Finally, the possible existence of an area of less stiff soil to the south-west of the Unit 1 BWST has no effect on the validity of this design approach. This is because that area has been stabilized by the water load test and subsequent surcharge of the valve pit, and also because the extrapolation of settlement patterns used in designing the new ring beam implicitly takes this area into account.511 284. The settlement values used by Bechtel in designing the new ring beams were independently confirmed by Dr. Hendron.

Dr. Hendron also confirmed that the factor of safety against bearing capacity failure of the modified ring walls will be 509 i

Boos and Hanson, prepared testimony at p. 15, follow-ing Tr. 7173.

510 Boos and Hanson, prepared testimony at pp. 4, 7, following Tr. 7173; Boos, Tr. 7212-7213; Hood, Singh and Kane, prepared testimony at p. 17, following Tr. 7444.

511 Boos, Tr. 7943-7945.

-201-adequate and in excess of accepted normal practice for both long term static and for static plus earthquake loadings. Dr.

Hendron also derived the appropriate long term soil stiffness values used in the static analyses of BWSTs.512 Although it was outside the scope of his prepared testimony, Dr. Hendron agreed with the range of short term moduli used in the seismic analy-ses of the BWST foundations.513 285. The NRC Staff and their consultant, the Corps of Engineers, reviewed and approved the settlement values and other soil parameters used in the design of the ring beam.514 The NRC Staff's structual engineering witness, Mr. Rinaldi, stated that the Applicant's proposal to add a new ring beam to the existing foundation was "in concept... structurally ade-quate", subject to a number of stated concerns, all of which have subsequently been satisfied.515 512 Hendron, prepared testimony on BWST foundations follow-ing Tr. 7186. In computing the factor of safety against bearing capacity failure due to static plus earthquake landings, Dr.

Hendron used a 0.19g earthquake. See Hendron, prepared testimony on BWST foundations at pp. 14 and 24 and Figure 19, following Tr. 7186.

13 Hendron, Tr. 7207-7208; Boos, Tr. 7214.

514 Hood, Singh and Kane, prepared testimony at pp.

14-16, following Tr. 7444.

15 Rinaldi and Matra, prepared testimony on BWSTs, etc.

at p. 9 following Tr. 7537; Tr. 7538-7545. At the end of the evidentiary session, Mr. Rinaldi's concerns were reduced to ,

three in number: (1) whether Bechtel had used earthquake loads equal to 1.5 times the FSAR SSE along with ACI-349 as supple- i mented by Regulatory Guide 1.142 in evaluating the structural i adequacy of the modified BWST foundations; (2) whether Bechtel had in fact checked all regions of the new ring beams for all the load combinations in ACI-349 as modified by Regulatory (Footnote 515 continued on page 202) l 1

a

-202-286. Upon completion of the reinforced ring beam, the Unit l'BWST will be releveled. Releve~tng of the empty tank will include draining and venting t: e tank, mounting strain gauges, raising the tank, leveling the existing ring wall, releveling the oil-sand layer below the bottom plate, install-ing Celotex underneath the tanks and reattaching the tank to the foundation by anchor bolts.516 Analyses show that the Unit 2 BWST, which-has not undergone significant differential settle-ment, can withstand future predicted settlement and the SSRS l earthquake without being releveled.517 (Footnote 515 continued from page 201)

I Guide 1.142; and (3) whether using 1.5 times FSAR SSE loads for the BWST gives greater loads than the SSRS. Each of these 4

concerns was answered affirmatively by Applicant's witnesses

under oath. See Boos, Tr. 7949-7951; Hanson, Tr. 7278-7280; Kennedy, Tr. 7388-7389, 7395-7398. The NRC Staff ultimately l resolved the first two concerns in a structural audit of Bechtel, I as documented in SSER #2, 6 3.8.3.3. Final resolution of the third concern, as far as the Staff is concerned, awaits comple-tion of the Seismic Margin Review. However, the Staff finds

" strong evidence" that the ring beam design based on 1.5 times FSAR SSE loads will be acceptable to them. See Rinaldi, pre-pared testimony on intervenors' contentions at p. 8, follow-ing Tr. 12080.

516

. Boos and Hanson, prepared testimony at pp. 8-9, following Tr. 7173; Tr. 7175-7176; SSER #2, 5 3.8.3.3 at pp.

3-21 to 3-22. Dr. Robert P. Kennedy recommended, and Applicant has committed itself to reinstalling a layer of Celotex, asphalt inpregnated fiberboard, under Tank T1. With the Celotex applied, l the tank can withstand the foundation being at least a quarter inch out of a rigid plane and be in compliance with code allow-able stresses. Kennedy, Tr. p. 7347, 7382. The celotex serves to aid the transmittal of loads to the foundation. While there is no regulatory requirement specifically addressing this problem, the Staff acknowledged the use of Celotex as an accept-able method of meeting NRC requirements. Rinaldi, Tr. pp.

7550-7553.

517 Kennedy, Tr. 7349; Campbell, Tr. 7349; Rinaldi, Tr.

7544-7545; SSER #2, 5 3.8.3.3 at pp. 3-21 to 3-22.

-203-287. The BWST tanks (as distinguished from the BWST founda-tions) were evaluated by Dr. Kennedy and Mr. Campbell of Struc-tural Mechanics Associates for stresses incurred due to uneven support conditions resulting from differential settlement of the foundations. Examination of field measurement data estab-lished that the Unit 1 BWST tank had been exposed to more severe conditions and that verification of the integrity of that tank would unquestionably verify the integrity of the Unit 2 BWST. From the anchor bolt loading (determined by strain gaging the bolts) and the known weights of tank components, all loading conditions were known. The nonuniform support reactions and resulting tank wall stresses were computed utilizing a ,

finite element model and incorporating laboratory determined properties of the Celotex on which the tank rests.518 The governing design codes is the ASME Boiler and Pressure Vessel Code, Section III, Nuclear Power Plant Components, Subsection NC , 1974, supplemented by ASME Code Case 1607-1 to establish allowable stresses for conditions other than normal cperation (infrequent events).519 The results showed that normal operat-518 Kennedy and Campbell, prepared testimony at p. 2, following Tr. 7345.

519 Kennedy and Campbell, prepared testimony at p. 3, following Tr. 7345. The ASME Code design rules do not specifi-cally cover settlement induced stresses. Therefore Dr. Kennedy and Mr. Campbell followed what they considered to be the intent of the Code in using the second level of stress in the Code

(" service level C") applicable to plant emergency conditions or infrequent loading conditions, to assess the effect of settle-ment. At this level the Code recognizes that some permanent deformation is possible but that the equipment will remain serviceable. Id. See also Tr. 7350-7351; 7433-7434.

. .- . - . -= - - _ . -- - . - -

, -204-i.

! ing stress limits of the governing design code were met, with two exceptions. One exception was that the most highly loaded i

bolt chair top plate did not meet normal operating stress

( limits, but the emergency event loading criteria for an ASME Code Class 1 plate-and shell type component support were met.

A subsequent dye penetrant examination of the top plate welds verified that no cracking was present. Careful visual inspec-tions by Dr. Kennedy and Mr. Campbell did not indicate any visible deformation to any bolt chairs.520 The other exception i

was local tank wall compressive stresses, which did not meet normal. operating stress limits. Again, the emergency event buckling criterion was used to verify freedom from buckling.' A buckling factor of safety of 2.46 was also calculated to demon-

! strate that a large margin existed for tank buckling.521 3

! visual examination of the tanks performed by Mr. Campbell while e ,

, they were under their most highly stressed conditions also f verified that no buckling was present. Thus, Dr. Kennedy and l Mr. Campbell concluded that the uneven support which resulted l

520-l' Kennedy and Campbell, prepared testimony at p. 3, following Tr. 7345. If there nad been significant buckling, it could easily have been observed visually. Kennedy, Tr. 7429-7430. Ultrasonic and X-ray inspection methods are not applic-able to this type of weld. Campbell, Tr. 7430-7431.

521 Kennedy and Campbell, prepared testimony at pp. 3-4, following Tr. 7345. The 2.46 buckling factor of safety was i calculated by using a NASA developed formula documented in NASA publication 8007, as opposed to the more conservative methods recommended by ASME Code. Using Code recommended calculations, t the BWST is nine percent under Service Level C allowable stresses.

However, Dr. Kennedy testified that the NASA formula is more appropriate for the nonuniform axial loading of the BWST than the method recommended by the Code, which assumes uniform axial compression. Tr.7370-7381.

..--.,,-w, ,,.,,-,4.r.v.,,- ,.v._ .-,..-,.,..-<-,,,.-,,r.--.--c.----.-..,,------,---, ,,.-------w-.---,,,------- .--.--...+.,-.w--rv- ~ . .

-205-from soil settlement has not resulted in any damage to the tanks.522 288. Dr. Kennedy and Mr. Campbell also testified that the Unit 1 tank after releveling and the Unit 2 tank without re-leveling could withstand the future differential settlement predicted by Applicant together with the SSRS earthquake with-out exceeding the Code allowable stress level. Therefore, the safe operating life of the tanks has not been reduced.523 289. The NRC Staff has reviewed Applicant's evaluation of the current condition of the tanks and has also concluded that the nonuniform support condition did not impose any unacceptable stresses on the tank components.524 ,

290. Subsequent to the construction of the new ring beam, two observation pits will be provided for each BWST foundation at the high stress locations. The new ring beams will undergo monitoring for a period of at least six months after the tanks are initially filled with water. Upon completion of a six-month monitoring period, a report evaluating the effect of any existing cracks will be submitted to the NRC. However, if dur-ing the monitoring period any crack reaches 0.03 in, or larger, the tanks will be emptied and the condition evaluated.525 22 l Kennedy and Campbell, prepared testimony at p. 4, following Tr. 7345; Kennedy, Tr. 7433-7434.

523 Kennedy and Campbell, prepared testimony at p. 4, following Tr. 7345; Kennedy, Tr. 7348, 7351, 7431-7433.

524 Rinaldi and Matra, prepared testimony on BWSTS, etc.

at p. 5, following Tr. 7537, Tr. 7565-7569.

525 Boos and Hanson, prepared testimony, pp. 20-21, and Figure BWST-2, following Tr. 7173; Rinaldi, Tr. 7562; SSER #2, 5 3.8.3.3, at p. 3-22.

4

-206-The BWST foundation settlement will also be monitored on a long-term basis as part of the foundation survey. During the operating life of the plant, Applicant will utilize strain gauge monitoring in the area of interest, the transition zone where the high stresses occur, to demonstrate that the ring beam foundation is performing adequately.526 291. Stamiris contention 4C(c), as amended, states as follows:

4. Consumers Power Company performed and proposed remedial actions regarding soils settlement that are inadequate as presented because:

C. Remedial soil settlement actions '

are not based on adequate evalua-tion of dynamic responses regard-ing dewatering effects, differen-tial soil settlement, and seismic effects for these structures:

(c) Borated water storage tanks.

292. Contrary to Ms. Stamiris' Contention 4C(c), Applicant has adequately evaluated and analyzed the dewatering, differen-tial soil settlement and seismic effects for the remedial surcharging of valve pits, construction of a new ring beam and l releveling BWST-1 measures which have been proposed and adopted.

293. As stated in paragraphs 283 through 285, Applicant's proposed addition of a new ring beam to the BWST foundation is 526 Boos, Tr. 7176-7178, 7320-7321; Hanson, Tr. 7178-7179. Mr. Boos testified that in terms of developing a tech-l nique for future monitoring of the concrete foundation, the area of interest was small enough that traditional optical survey methods for determining displacements in the ring founda-tion would not suffice to detect the rotation of the concrete member, which is a reflection of the induced bending moments and stresses. Tr. p. 7176.

1

-207-based on a conservative prediction of future settlement which ,

1 has been independently confirmed by Dr. Hendron and reviewed l and approved by the NRC Staff and the Corps of Engineers. The prediction is conservative because it ignores the effect of the water load test and surcharging the valve pits, which will reduce future differential settlements. It is also conser-vative because the BWST foundations, as modified by the new ring beam, will be stiffer than the old foundation and thus undergo less differential settlement than extrapolations of past settlement would indicate. The BWST tanks themselves have been shown to be unharmed by past differential settlement and able to withstand predicted future differential settlements without exceeding normal operating service level stresses, see paragraphs 287-289, supra.

294. In its prediction of future differential settlement for the BWSTs, Applicant took into account possible dewatering effects.527 295. Applicant has also adequately analyzed the effect of potential seismic activity in developing its remedial soil measures for the BWSTs. The new ring beam interface shear connectors and new ring foundation are designed to resist re-sulting stress requirements without exceeding the allowable 528 stress values and load combinations identified in ACI 318 527 Rinaldi and Matra, prepared testimony on BWSTs, etc.

at p. 12, following Tr. 7537. Boos and Hanson, prepared testi-mony at Figure BWST-8; Rinaldi, prepared testimony on intervenors' contentions at p. 3, following Tr. 12080.

528 Boos and Hanson, prepared testimony at pp. 11-12.

l 1

-208-and ACI 349-76, as supplemented by Reg. Guide 1.142. These criteria meet with Staff approval since they conform with re-quirements set forth in SRP Section 3.8.4.529 296. At the time the remedial steps for the BWSTs were being initiated the site-specific response spectra (SSRS), had not yet been developed. Applicant, in order to proceed with the design of its proposed new foundation ring beam adopted the conservative load formula of 1.5 multiplied by the FSAR SSE.530 Dr. Kennedy testified that this procedure would result in higher stresses than the SSRS, which is equivalent to about 1.3 times the FSAR.531 In paragraphs 73-76 of this Partial Initial Decision, the Board notes its approval of the seismic model of the BWST developed by Dr. Kennedy and accepted by the NRC Staff.

297. Although in its May 5, 1981 Prehearing Conference Order the Licensing Board deferred until subsequent stages of the operating license proceeding the question of whether the structures as built conform to newly determined seismic criteria, preliminary evidence indicates that the BWST, as modified, does in fact meet such criteria. Dr. Kennedy testified that there is a substantial margin for the design of the tank and the foundation, taking into account both the predicted future 529 SSER # 2, 5 3.8.3.3 at p. 3-18 through 3-21.

530 SSER # 2, 9 3.7.2 at pp. 3-2 to 3-3. Rinaldi, pre-pared testimony on intervenors' contentions at p. 8, following Tr. 12080.

531 Kennedy, Tr. 7389.

-209-differential settlement of the foundation and the SSRS.

Although it has not yet formally reviewed the results of the seismic Margin Review, based on preliminary information provided by the Applicant, the Staff also reports " strong evidence" that the BWSTs comply with design and acceptance criteria acceptable to the Staff.533 298. Applicant's witness, Dr. Richard Woods, a consultant for Bechtel, evaluated the potential for seismic shakedown settlement at the Midland site. Although pockets of sand which have a potential for shakedown settlement exist at several site locations, Dr. Woods testified that the soil under the BWSTs exhibited no potential for such settlement because clay is -

present below the tanks. Moreover, the sand within the ring foundation has been compacted to a relative density greater than 80% for which no significant seismic shakedown settlement will occur.534 Applicant has shown and Staff agrees that the materials underneath the BWSTs are not subject to liquefac-tion.

299. The Board concludes that the concerns set forth by Ms. Stamiris in Contention 4C have been adequately addressed in

! Kennedy, Tr. 7395-7399.

l

' 533 Rinaldi, prepared testimony on intervenors' conten-tions at p. 8, following Tr. 12080.

534 Woods, prepared testimony on seismic shakedown at pp. 3-6, following Tr. 11549.

535 Woods, prepared testimony on liquefaction, following Tr. 9745; SSER #2, at pp. 2-43 and 2-44. Intervenor Sharon Warren's Contention 2.B. expressed concern for liquefaction adversely affecting the BWSTs. Mr. Kane testified that the Staff is satisfied that liquefaction is not a problem for the BWST structures. Tr. 9817.

-210-the remedial soil measures being taken for the BWSTs. Applicant has shown and Staff verified that the remedial measures, assum-ing they are successfully completed, will provide reasonable assurance that the BWSTs will perform their intended safety functions throughout the 40 year operating life of the plant.

Moreover, Staff approved methods of monitoring the BWSTs for settlement, concrete cracking and strain provide additional assurance that any unanticipated future differential settlement would be detected and corrected before presenting any risk to the public health and safety.536 536 The above conclusions are also dispositive of Warren Contention 1, insofar as it relates to the BWSTs. Warren Contention 1 states:

The composition of the fill soil used to prepare the site of the Midland Plant --

, Units 1 and 2 is not of sufficient quality to assure that pre-loading techniques have permanently corrected soil settlement problems. The NRC has indicated that random fill dirt was used for backfill.

The components of random fill can include loose rock, broken concrete, sand, silt, ashes, etc. all of which cannot be com-I pacted through pre-loading procedures.

1 NRC Staff members, Mr. Hood, Mr. Singh and Mr. Kane testified that they did not agree with Ms. Warren's Contention 1, insofar as it argues that pre-loading procedures and construction of the new ring beam has not corrected the soils settlement problems for the BWSTs. To begin with, Staff criticized Ms. Warren's definition of " backfill". The concrete identified by borings and excavation in the plant fill was intentionally placed during construction and is not considered to be in broken pieces with large voids. Also, there is no evidence of loose rock or ashes being discovered in the foundation of any Seismic Category 1 structure. Further, the Staff witnesses stated that preloading measures performed have improved the density and engineering properties of the foundation soils, and remedial measures presently being carried out by Applicant serve to eliminate concerns for unacceptable future differential settle-ment. Hood, Singh, Kane prepared testimony at pp. 16-18, following Tr. 7444.

-211-DIESEL FUEL OIL TANKS 300. There are four Seismic Category I steel diesel fuel oil storage tanks at the Midland Nuclear Power Plant site.

They are located to the southeast of the diesel generator build-ing and are buried approximately six feet underground.537 The tanks' three feet thick concrete foundations rest predominately on a supporting base of medium stiff to medium dense sandy clay compacted backfill material.538 301. The function of the emergency diesel fuel system is to supply fuel to the onsite diesel generators in case of loss of offsite power.539 Eight diesel fuel oil lines provide fuel oil supply and return between the diesel generators and the four buried diesel fuel oil storage tanks.540 302. The diesel fuel oil storage tanks were designed and fabricated to the requirements of ASME Code, Section III, Class l

3 (1974). Their concrete foundations were designed and fabri-cated to the requirements of ASME Code, Section III, Class 3 (1974) and also, ACI 318-71. The tiedown is designed to the 537 l

Rinaldi and Matra, prepared testimony on BWSTs, etc.

at p. 10 and Attachment 4, following Tr. 7537.

538 Kane, Tr. 12072; Testimony of Donald F. Landers, Donale F. Lewis, and James Meisenheimer on behalf of Applicant Regarding Piping and Tanks at the Midland Plan (hereinafter,

" Landers, Lewis, and Meisenheimer") at pp. 7-8, following Tr.

7619.

539 Testimony of W.P. Chen and Darl Hood for the NRC Staff Regarding Underground Seismic Category I Piping (herein-after, "Chen and Hood") at p. 4, following Tr. 7762.

540 SER, 6 1.12.10, at p. 1-25.

1 I

-212-AISC-1971. The Staff has determined that the load combinations and acceptance criteria utilized by Applicant in designing the )

four storage tanks, meet its applicable design requirements.541 -

l l

303. Applicant has undertaken a program of measurement, analysis and monitoring to assure that the diesel fuel oil storage tanks can perform their intended functions throughout the operating life of the plant.542 The diesel fuel oil storage tanks had been installed approximately two years after the fill was placed, and therefore, were isolated from the effects of the fill's initial settlement. Applicant filled the four tanks with water and monitored settlement for about an eight month period.

Settlement of the tanks during this period was minimal.543 ,

304. NRC Staff witness Mr. Joseph Kane, testified that the Staff is not concerned about the foundation stability of the four diesel fuel oil storage tanks.544 Mr. Kane stated that a total maximum settlement of a half-an-inch was the largest settlement recorded for the diesel fuel oil storage tanks.

Following surcharging in 1979, the tanks experienced a maximum 541 Rinaldi and Matra, prepared testimony on BWSTs, etc.

at p. 10, following Tr. 7537.

542 Rinaldi and Matra, prepared testimony on BWSTs, etc.

at p. 10, following Tr. 7537; Rinaldi, prepared testimony on intervenors' contentions at pp. 5-6, following Tr. 12080. The buried utilities add little weight to the fill and therefore have very little impact on present and future settlement below their invert elevations. Id. at 9.

543 Landers, Lewis and Meisenheimer, prepared testimony at p. 11, following Tr. 7619. ,

544 Kane, prepared testimony regarding the Effects of the Plant Fill Problem on Foundation Support for the Seismic Cate-gory I Underground Piping, p. 12, following Tr. 7444.

l

-213-settlement of a quarter of an inch, an additional quarter inch settlement occurred as a result of temporary dewatering condi-tions, however, when the groundwater table was allowed the rebound, settlement rebounded to four-tenths of an inch. Dur-ing the operating life of the plant, additional settlement of approximately a half-an-inch has been estimated.545 305. Applicants' witnesses Mssrs. Landers, Lewis and Meisenheimer testified that the Diesel Fuel Oil Storage Tanks will settle with the surrounding soil, as will the connecting pipes. Thus, the differential settlement between the pipes and the tanks will be small, and the nozzle loads due to settlement, insignificant.546 ,

306. The NRC Staff, in recognizing and accepting the settle-ment values relating to the storage tanks,547 concluded that the results of the analysis and monitoring program performed by the Applicant indicated that they do not anticipate any significant problem for these tanks or their pedestals resulting from dif-ferential settlement;548 and there is no reason for any struc-tural concerns relating to the effects of differential soil settlement on the diesel fuel oil storage tanks.549 545 Kane, Tr. pp. 12071-12073, 12090-12091.

546 Landers, Lewis and Meisenheimer. prepared testimony at p. 11, following Tr. 7619.

547 Kane, Tr. 12073. See also Hood, Tr. 2759-2760.

548 Landers, Lewis and Meisenheimer, prepared testimony at p. 11, following Tr. 7619.

549 Rinaldi, prepared testimony on intervenors' contentions at pp. 5-6, following Tr. 12080; Rinaldi and Matra, prepared testimony on BWSTS, etc. at p . 12, following Tr. 7537.

i

-214-307. Stamiris contention 4C(d), as amended, states as follows:

4. Consumers Power Company performed and l proposed remedial actions regarding soils settlement that are inadequate as presented because:

C. Remedial soil settlement actions are not based on adequate evalua-tion of dynamic responses regard-ing dewatering effects, differen-tial soil settlcment, and seismic effects for these structures:

(d) Diesel Fuel Oil Storage Tanks.

308. Contrary to the allegation of Ms. Stamiris' Conten-tion regarding the diesel fuel oil storage tanks, Applicant has adequately analyzed and evaluated the effects of dewatering, seismic events, and differential soil settlement on these tanks.

As stated above, Applicant has analyzed and monitored the tanks for the effects caused by the soil supporting them. Applicant found the tanks to be in an acceptable and functionally capable O

condition, leading the Staff to express its belief that any structural concerns regarding the fuel tanks which are repre-sented in contention 4C(d) are without merit.551 309. The effects of dewatering on settlement of the diesel fuel oil storage tanks has been taken into account. As stated in paragraph 6, following dewatering the tanks reached a maxi-mum settlement of half-an-inch. When the groundwater table was 550 Landers, Lewis and Meisenheimer, prepared testimony at pp. 11 and 35, following Tr. 7619.

51 Rinaldi, prepared testimony on intervenors' contentions at p. 6, following Tr. 12080, Rinaldi and Matra, prepared testi-mony on BWSTS, etc. at p. 12, following Tr. 7537.

l \

-215-allowed to rebound to the full scale recharge test, rebound l i

settlement of one-tenth of an inch occurred. The Staff has l found these settlement values acceptable.552 l 310. Applicant has also analyzed the fuel storage tanks for seismic induced loads in conjunction with normal, thermal and differential settlement loads. In addition, they have provided a reinforced concrete cover to resist the impact of postulated tornado missiles. As noted in paragraph 3, the Staff has determined that the load combinations and acceptance criteria used by Applicant to design and fabricate the tanks -

meet the Staff's design criteria.553 311. Dr. Richard Woods, a professor of civil engineering, and consultant for Bechtel Power Company, evaluated and testi-fied to the potential for seismic shakedown settlement of loose sands at the Midland Plant. His analysis revealed that sands for which there is a potential of shakedown settlement exist in a number of site locations. One boring performed in the diesel fuel oil storage tank area revealed the existence of loose sand. Dr. Woods testified that the maximum shakedown settle-ment which would occur based on this condition amounts to about 552 Kane, Tr. pp. 12072-12073.

553 Rinaldi, prepared testimony on intervenors' contentions at p. 6, following Tr. 12080; Rinaldi and Matra, prepared testi-mony on BWSTS, etc. at p. 10, following Tr. 7537. The tanks have been designed for the original seismic loads of the FSAR.

In the Seismic Margin Review, the tanks will be reevaluated using the site specific response spectra. Rinaldi, prepared testimony on intervenors' contentions at p. 8, following Tr.

12080.

i

-216-0.10 inch. These settlements do not present any hazard to the diesel fuel oil storage tanks.554 312. Dr. Woods also presented testimony regarding the potential for liquefaction at the buried diesel fuel oil stor-age tanks. Dr. Woods explained that during the initial lique-faction boring study, a loose sand pocket was discovered in one of the borings close to the storage tanks. Using a very con-servative approach to analyze the liquefaction potential,555 an earthquake producing a peak ground acceleration of .19g was postulated and the effect on the surrounding soils was analyzed.

Dr. Woods concluded, and the Staff is satisfied that no danger of liquefaction exists for the tanks.556 ,

313. The Board concludes that the concerns set forth by Ms. Stamiris in Contention 4C(d) regarding the diesel fuel oil storage tanks have been adequately addressed. There is reason-able assurance that the diesel fuel oil storage tanks will -

perform their intended functions throughout the life of the plant under both normal and accident conditions without pre-senting any risk to the public health and safety.

554 Woods, prepared testimony on seismic shakedown at

p. 7 and Figure 3, following Tr. 11549. See also Kane, Tr.

11558.

555 Woods, Tr. 9747-9748. Although the boring showed this not to be the case, it was assumed for purposes of demon-strating the behavior under liquefaction that the sand pocket might exist under the entire tank area.

56 Woods, Tr. 9776-9777 and Figure L-3 following Tr.

9745; Kane, Tr. 12072-12073. SER, 5 1.12.4 at p. 1-22, and 5 2.4.6.1 at pp. 2-24 to 2-25. This evidence adequately re-solves the concerns expressed in Warren Contention 2.B.2.

-217-UNDERGROUND PIPING A. INTRODUCTION 314. Ms. Barbara Stamiris submitted two Contentions relat-ing to underground piping at the Midland plant.557 Stamiris Contention Nos. 4(A)(4) and 4(C)(f) allege:

4. Consumers Power Company performed and proposed remedial actions regarding soils settlement that are inadequate as presented because:

(A) Preloading of the diesel genera-tor building (4) may adversely affect under-

lyingpiping,congggtsor nearby structures 557 Ms. Sharon Warren also submitted a contention relat-ing to underground piping at the Midland plant. This conten-tion (Warren Contention No. 3) alleges:

1 Pre-loading procedures undertaken by Con-sumers Power have induced stresses on the diesel generating building structure and have reduced the ability of this structure l to perform its essential functions under that stress. Those remedial actions that have been taken have produced uneven settle-ment and caused inordinate stress on the structure and circulating water lines, fuel oil lines, and electrical conduit.

Ms. Warren is no longer an intervenor, and her Contention is therefore not at issue. Nevertheless, the Licensing Board has addressed her concerns below.

558 For a discussion of the effect of the preloading on electrical conduits, see paragraphs 417-421, infra. For a discussion of the effect of the preloading on nearby struc-

! tures, see paragraph 189, supra.

)

-218-(C) Remedial soil settlement actions are not based on adequate evalua-tion of dynamic responses regard-ing dewatering effects, differen-tial soil settlement, and seismic effects for these structures:

(f) RelatedgggerlyingPiping&

Conduit.

315. A concern for foundation stability of underground piping at the Midland plant arises because the plant fill supporting the piping was found to be inadequately compacted and settling under its own weight. Consequently, piping buried in the plant fill has settled with the fill. In addition, observed settlements have not been uniform because of the highly variable soil fill conditions and the settlement of '

structures connected with underground piping.560 316. The Applicant and the NRC Staff have identified those underground piping systems and components which are important to safety and which are designed to withstand the effects of the earthquake forces applicable for the Midland site. These systems and components are designated as Seismic Category I items.561 Applicant and the NRC Staff seek to ensure through analysis, remedial measures and monitoring that the Midland underground Seismic Category I piping will perform its intended 559 Stamiris Contention No. 4(C)(f), as amended by Ms.

Stamiris' Answer to Applicant's Interrogatories, dated April 20, 1981.

560 SER, 5 1.12.10, p. 1-25.

561 SER, 5 1.12.10 at pp. 1-25 to 1-26, 5 3.9.3.1 at pp.

3-28 to 3-30; SSER #2, Table 3.1, p. 3-33. For a discussion of the earthquake forces applicable to Seismic Category 1 items, see paragraphs 1-58, supra.

-219-safety function over the 40 year service life of the plant. In addition, at Midland there are certain underground piping l systems not designated as Seismic Category I. These non-Seismic Category I systems have been reviewed to ensure that postulated failures could not have an adverse impact on nearby Seismic Category I structures or piping.562 B. UNDERGROUND PIPING OTHER THAN SEISMIC CATEOGRY I 317. As is described in the chapter of this Partial Initial

, ecision which deals with liquefaction and dewataring,563 it has been determined that, if the Midland site permanent dewatering l

system lowers and maintains groundwater levels below elevation l

610 in the vicinity of the DGB and the railroad bay area of the L

auxiliary building, there will be no danger due to liquefaction at the site. At the request of the NRC Staff, the Applicant analyzed breaks in non-Seismic Category I underground piping and the effects such breaks would have on the ability of the permanent dewatering system to maintain water levels below j elevation 610 in these areas.564 562 SSER #2,~l 3.9.3.1.2 at p. 3-34; SER $ 2.4.6.3 at pp.

2-28 to 2-29; SSER #2, 5 2.4.6.3 at pp. 2-5 to 2.6. Cf. Kane, l l Tr. 3646-3647. Mr. Kane indicates that the label " Category I" l l

applied to an item is not dispositive; rather, the safety considerations in the event of of a failure of such an item are i the principle controlling factor.

563 See paragraphs 422 et seq. below.

64 SER, 5 2.4.6.3, p. 2-28. The potential for liquefac-ticli af soils to the north and west of the SWPS will be elimi-i nates by replacement of the loose sands in that area. For a l

detailed discussion of the Midland site dewatering system and j liquefaction potential see paragraphs 422 et seq., infra.

-220-318. Several non-Seismic Category I lines, called circulat-ing water discharge lines ("CWDL's"), are located to the east and west of the DGB, about 18 feet below the DGB's base mat.565 In this area, the dewatering system will normally control the groundwater level to elevation 595. The Applicant performed an analysis of a postulated failure of the Unit 2 CWDL.566 This analysis established that the groundwater level would rise to elevation 607 over a period of approximately 3.3 days before the closest area dewatering well would automatically activate.

Thereafter, operation of only one well would be sufficient to prevent groundwater from rising significantly above elevation 610. However, should all the area dewatering wells be inoper-able at the time of the pipe break, the rising groundwater would trigger the permanent dewatering monitoring system, resulting in appropriate actions under the proposed Technical Specifications . Moreover, the top of the Unit 2 CWDL is at elevation 610; thus, groundwater levels are not expected to rise significantly above this elevation as a result of a CWDL break.567 565 See SSER #2, 5 2.5.4.4.5, Figure 2.11, for the loca-tion of this piping.

l 566 This line was analyzed because it is the largest non-Seismic Category I underground pipe near a critical struc-ture. See Testimony of William C. Paris, Jr. Regarding Perma-nent Dewatering System for the Midland Site (hereinafter " Paris, prepared testimony") at p. 34, following Tr. 9900; Paris, Tr.

9938-9943; SER, 5 2.4.6.3, p. 2-28.

567 See SER, 5 2.4.6.3, pp. 2-28 to 2-29; Paris, Tr.

9938-9943. See also discussion at paragraphs 443 and 444, nfra.

N

-221-319. The Applicant also analyzed the non-Seismic Cate-gory I condensate storage lines ("CLS's") for a postulated failure. These lines consist of the two 20-inch diameter supply lines and two 6-inch diameter return lines that run from the condensate storage tanks (" CST's") located near the south-east corner of the DGB, underneath the DGB to condensers located in the turbine building.568 320. Prior to the placement of the DGB surcharge, the l

Applicant committed to monitoring the CSL's Eo as to evaluate

.i pressures imposed on the line by the surcharge.569 In addi-l tion, both CSL's were severed on the north side of the DGB at a i

point between the DGB and the turbine building so as to relieve stresses on the line and to the DGB due to settlement.570 321. As a result of its analysis, the Applicant has con-cluded that, if any of the CSL's were to break so that the entire liquid inventory of the affected CST were to drain out through the break and. remain in the area directly beneath the DGB, the groundwater would not exceed elevation 610 even if the area dewatering wells were not cperational. The Staff has reviewed and concurred with the Applicant's analysis.571 i

68 SER, i 2.4.6.3, p. 2-29. See SSER #2, Figure 2.11 for the location of the CSL, designated 20"-IHDC-169, and the two CST's. Figure 2.11, however, is incorrect in that it indicates only one out of the four CSL's. Tr. 9123.

I 69 Kane, Tr. 4404-4406; Gallagher, Tr. 2455-2456.

O See, e.g., Hood, Tr. 4199-4200.

See SER, 5 2.4.6.3, p. 2-29; SSER #2, 5 2.4.6.3,

p. 2-5. See also discussion at paragraphs 443 and 444, infra.

l 4

.-. _ . , . , n..,- . , , . - . . . - - , . . . _ - , _ . - - , _ , _ _ . - , - - _ , _ . , -. . . . - _ _ _ . - , _ , , . . - _ . - - _ . . . . _ - - . - . - - .

-222-322. The Applicant has also evaluated a postulated break in a dewatering system header line. In this event, inflow of water could exceed the capacity of the affected dewatering pumps, producing a rise in groundwater in the immediate vicinity of the affected wells. The installation of flexible header diversion hoses and backup interceptor wells provides reason-able assurance that groundwater levels will not rise above elevation 610.512 323. A break in the 66-inch concrete cooling pond blowdown line would have minimal impact on groundwater levels because of the low pressure delivery of this line. The dewatering system has sufficient capacity to remove the volume that would be '

introduced into the groundwater due to a rupture in this line.573 C. SEISMIC CATEGORY I UNDERGROUND PIPING -- IN GENERAL 324. Five types of buried Seismic Category I piping, ranging in size from 1 to 36 inches in diameter, serve safety functions at the Midland plant.574 The first type includes the 572 See SSER #2, 9 2.4.6.3, pp. 2-5 to 2-6. See also paragraphs 443 and 444, infra.

573 SSER #2, $ 2.4.6.3, p. 2-7; Paris, prepared testimony at p. 33, following Tr. 9900.

574 The Seismic Category I piping in the Midland plant fill is identified as follows:

Diesel Fuel Oil Lines 1-1/2"-lHBC-3 2"-lHBC-497 1-1/2"-lHBC-4 2"-lHBC-498 l-1/2"-2HBC-3 2"-2HBC-497 1-1/2"-2HBC-4 2"-2HBC-498 (Footnote 574 continued on page 223)

-223-diesel fuel oil lines serving the emergency diesel generators.

Four 1-1/2-inch diameter and four 2-inch diameter ASME Code 575 Class 3 carbon steel pipes provide fuel oil supply and return (Footnote 574 continued from page 222)

Borated Water Lines 18"-lHCB-1 18"-lHCB-2 18"-2HCB-1 18"-2HCB-2 Service Water Lines 8"-lHBC-310 26"-OHBC-54 8"-2HBC-81 26"-OHBC-55 8"-lHBC-81 26"-OHBC-56 8"-2HBC-310 26"-OHBC-15

8"-lHBC-311 26"-OHBC-16 8"-2HBC-82 26"-OHBC-19 8"-lHBC-82 26"-OHBC-20 8"-2HBC-311 36"-OHBC-15 10"-OHBC-27 36"-OHBC-16 10"-OHBC-28 36"-OHBC-19 26"-OHBC-53 36"-OHBC-20 Control Room Pressurization Lines 4"-ODBC-1 1"-OCCC-1 Penetration Pressurization Lines 1"-lCCB-45 1"-2CCB-46 SSER #2, Table 3.1.

Applicant's letter of March 16, 1982 (Serial 16269) identified a 10 foot length of 48-inch diameter line (48"-OHBC-2/48"-OJYY-1) extending from the service water pump structure which, at the time, was classified by the Applicant as Seismic Category I.

Applicant has now reclassified this portion of the 48-inch diameter line as non-Seismic Category I. The NRC Staff agrees that failure of this 48-inch diameter line would not cause a loss of essential Service Water System cooling. SSER #2, 5 9.2.1, p. 9-1; See also SSER #2, S 3.9.3.1., pp. 3-32 and 3-33.

ASME Boiler and Pressure Vessel Code, Section III (1980 Edition, with Addenda through Winter, 1981).

-224-between the emergency diesel generators and four buried diesel fuel oil storage tanks located east of the condensate storage tanks.576 325. The second type of piping consists of borated water lines, which provide water from the borated water storage tanks for normal functions, emergency volume and reactivity control and for such postulated accidents as a pipe break in the reactor coolant system. Four 18-inch pipes constructed of ASME SA-358, Grade 304 stainless steel are included in this category. The piping was installed in accordance with ASME Code Class 2.577 326. The third type includes the service water system

("SWS") piping, which supplies water to various systems as -

needed under normal and accident conditions. Twenty-two lines ranging from 8 to 36 inches in diameter are in this category.

These lines are constructed of ASME Code Class 3 SA-106 and SA-155 carbon steel piping.578 l 327. The fourth type consists of piping in the control room pressurization system. This system supplies overpres-surization air to the main control room from two tanks buried to the east of the Auxiliary Building, during postulated acci-576 SSER #2, 5 3.9.3.1.1, p. 3-34; Landers, Lewis and Meisenheimer, prepared testimony at pp. 5, 7, following Tr.

7619. See also SSER #2, i 2.5.4.4.5, Figure 2.11.

577 SSER #2, 6 3.9.3.1.1, p. 3-34; Landers, Lewis and Meisenheimer, prepared testimony at pp. 5-6, 7, following Tr.

7619. See also SSER #2, i 2.5.4.4.5, Figure 2.11.

578 SSER #2, 9 3.9.3.1.1, p. 3-33; Landers, Lewis and l Meisenheimer, prepared testimony at pp. 6, 7, following Tr.

7619. See also SSER #2, 5 2.5.4.4.5, Figure 2.11.

-225-dents, such as releases of hazardous gases from offsite storage areas. One 4-inch ASME Code Class 3 carbon steel pipe and one 1-inch ASME stainless steel pipe are included in this category.579 328. The last category includes two 1-inch diameter ASME Code Class 2 carbon steel penetration pressurization lines.

These lines had not been installed as of November, 1982, (the month during which the latest hearings on buried piping were held).580 329. The smaller underground pipelines are seamless, while the 18-inch and larger diameter pipes are seam welded. These larger diameter pipes are fabricated in nominal lengths ranging approximately from 4 to 40 feet, which are fitted together and welded. The welds are inspected and hydrostatically tested to assure integrity.581 330. All of the underground Seismic Category I pipe at the Midland site rests on compacted backfill material. Insuffi-ciently compacted fill material was detected at a number of locations at the site. For this reason, the Applicant initiat-ed an investigation to evaluate fill material conditions.582 As part of the investigation, extensive soil borings were taken. These borings indicate that the consistency of the fill 579 SSER #2, 5 3.9.3.1.1, p. 3-34; Landers, Lewis and Meisenheimer, prepared testimony at pp. 6, 7, following Tr.

7619. See also SSER #2, 5 2.6.4.4.C, Figure 2.11.

580 See SSER #2, 6 3.9.3.1.1, p. 3-34.

581 Landers, Lewis and Meisenheimer, prepared testimony at p. 7, following Tr. 7619.

582 Landers, Lewis and Meisenheimer, prepared testimony at p. 7, following Tr. 7619.

-226-at the location of buried piping can vary considerably in a vertical direction within a boring, and also laterally as evidenced by closely spaced borings.583 331. Settlements that have been observed in buried piping are primarily a result of the fill settling under its own weight. The buried piping adds little, if any, weight to the fill and therefore has very little impact on present and future settlement below its invert elevations.584 332. Depth profiles along pipelines were compared with subsurface conditions projected from adjacent exploration borings. No correlation could be established between lower profile areas and softer underlying fill soils or between "

higher profiles and stiffer underlying fill soils. In areas where closely spaced borings indicate stiffer soils and softer soils adjacent to one another, no abrupt differential varia-tions were observed in the pipeline profiles.585 333. To permit an assessment of the condition of the underground piping because of the plant fill problem, internal profiling of some of the buried pipes was accomplished to establish pipe deflection (settlement) profiles.586 The results of the profiling indicate that the present pipe invert eleva-583 SSER #2, 5 2.5.4.4.5, p. 2-35; Landers, Lewis and Meisenheimer, prepared testimony at p. 8, following Tr. 7619.

584 Landers, Lewis and Meisenheimer, prepared testimony at p. 9, following Tr. 7619.

585 Landers, Lewis and Meisenheimer, prepared testimony at p. 9, following Tr. 7619.

586 See Landers, Lewis and Meisenheimer, prepared testi-mony at pp. 13-14, and attachments cited therein, following l Tr. 7619, for a discussion of the profiling techniques used.

l l

-227-tions have maximum deviations from 6 to 21 inches below the originally intended design invert elevations. The majority of these deviations are in the range of 9 to 11 inches. Field installation procedures for the installation of the piping allowed for a placement tolerance of plus-or-minus two inches from the design elevation. Even after accounting for installa-tion tolerances, it appears that pipe settlements of at least 4 to 19 inches may have occurred.587 334. Records of the monitored settlement within the fill have been utilized to predict future settlement for buried pipes. A series of markers (Borros anchors) have been install-ed at nine locations in the vicinity of buried piping not -

influenced by surcharge loadings. Settlement readings for anchors that have been established at depths of 7 to 12 feet below the surface were used in the analysis, because this depth is representative of the depth of most buried pipes or utili-ties. Soil conditions at these locations are representative of the variable soil conditions encountered throughout the fill.588 87 SSER #2, 9 2.5.4.4.5, p. 2-35; SER, S 1.12.10, p.

1-25. The allowable placement tolerance for installing the pipe in the field during constructon was plus or minus 2 inches from the established design invert elevation. Inspection records indicate that the pipes were installed within this tolerance, and no construction nonconformances related to this requirement were reported. However, as there are no profiles to verify post installation locations, it is not known how much of the deviation in invert elevations is due to soil settlement alone. Therefore, the Applicant and the NRC Staff have pro-ceeded on the assumption that all variations in design eleva-tion are due to settlement. See Chen & Hood, prepared testi-mony at p. 6 following Tr. 7762; Lewis, Tr. 7693-7695.

588 SSER #2, p. 2-36; Landers, Lewis and Meisenheimer, prepared testimony at p. 9, following Tr. 7619.

I l

l

-228-335. Borros anchors BA 13, BA 14, and BA 34 were installed in December 1978. Settlement data have been taken on these anchors for over four and one-half years. Borros anchors BA 100 through BA 106 were installed in September 1979, and over three and one-half years of settlement data exist for these anchors. The plots of settlement verus log-time for each of these anchors form straight lines which extrapolate to 2.0 to 2.5 inches of additional settlement occurring over the next 40 years. 89 The Applicant and the NRC Staff have determined that, based on these projections, a conservative estimate of future maximum settlement of buried piping or utilities is for not more than 3 inches of additional settlement to occur at any pipe location, provided only limited loads are placed over the piping. This estimate includes allowances for settlement due to both seismic shakedown and dewatering. Applicant has com-mitted to providing a Technical Specification that will include control measures restricting placement of heavy loads over buried piping and conduits.590 336. The maximum differential settlement along the longi-tudinal axis of buried piping is anticipated to occur at anchor points. The maximum critical differential settlement expected I along buried piping will be the difference between the future 589 Landers, Lewis and Meisenheimer, prepared testimony at p. 10, following Tr. 7619.

590 SSER #2, 5 2.5.4.4.5, p. 2-36; SER, $ 1.12.10, p.

1-25; Kane, prepared testimony at p. 6, following Tr. 7752; Landers, Lewis and Meisenheimer, prepared testimony at p. 10, following Tr. 7619; Shunmugavel, prepared testimony on duct banks at p. 6, following Tr. 12016.

-229-projected settlement of the building ent.ered at the anchor locations and the maximum estimated settlement of the fill in which the pipeline is buried.591 D. ASSURANCE OF SERVICEABILITY OF BURIED SEISMIC CATEGORY I PIPING I. STRESS ANALYSES AND DESIGN CRITERIA 337. Section 3.9.3 of the Standard Review Plan ("SRP")

defines the design criteria and load combinations to be employed However, in the design of ASME Code Class 1, 2 and 3 items.

stresses in piping resulting from differential soil settlement are not addressed in either SRP Section 3.9.3 or the ASME Code.592 338. To augment the SRP and the ASME Code, the Applicant 9

which would initially proposed a design criterion of 3S c have provided an acceptable conservative limit for its evalua-tion of the buried pipe.594 Stress analyses based on the 591 Landers, Lewis and Meisenheimer, prepared testimony at p. 10, following Tr. 7619.

592 SSER #2, S 3.9.3.1.3, p. 3-35. The 1971 Edition of the ASME Code, with Addenda through Summer, 1973 (which is generally applicable to the design of the Midland plan (see The 1977 Kane, Tr. 7815)), does not address settlement at all.

Edition of the ASME Code does, however, addressLewis See Landers, singleand point differential settlement stresses. following Tr. 7619.

Meisenheimer, prepared testimony at p. 23, 593 = three times the allowable basic#2,material stress 3S at minimum (8old) temperature, in psi SSER 5 3.9.3.1.3, note, p. 3-35.

594 SSER #2, 9 3. 9. 3.1. 3, p . 3 -3 5.

-230-assumption that existing deviations from design configurations are due solely to differential settlement yielded stresses which in some cases exceded the 3S c criterion.595 Subsequently, to provide a greater margin of safety, the Applicant proposed a combination of the 3S c criterion, additional design criteria, remedial action and monitoring to assure the safety and ser-viceability of the Seismic Category I underground piping.596 The remedial actions to be taken with respect to each type of buried pipe will be discussed in paragraphs 348-371, infra.

The proposed buried pipe monitoring program will be discussed in paragraphs 372-381, infra. The additional design criteria proposed by the Applicant are set forth in the following para-graphs.

(a) STRENGTH CRITERIA 339. These criteria are intended to provide assurance that the overall cross-sections of piping are capable of resisting the forces and movement due to all loads imposed upon the piping over the life of the plant. These loads include pres-sure, thermal expansion, overburden and traffic, soils settle-ment and seismic loads.597 595 SSER #2, 5 3.9.3.1.3, p. 3-35; Landers, Lewis and Meisenheimer, prepared testimony at pp. 23-24, following Tr.

7619; Chen and Hood, prepared testimony at p. 8, following Tr.

7762.

596 SSER #2, 5 3.9.3.1.3, p. 3-35; Chen and Hood, pre-pared testimony at pp. 8-9, following Tr. 7762.

597 SSER #2, 5 3.9.3.1.3, pp. 3-35 to 3-36; Chen and Hood, prepared testimony at p. 7, following Tr. 7762.

-231-340. For settlement stresses only, the 3S c criterion is an acceptable strength criterion.598 However, in cases where the 3S c criterion could not be satisfied, the Applicant and the NRC Staff considered the effects of load combinations that could lead to catastrophic effects in a short amount of time in comparison to the proposed monitoring frequency. In particu-lar, the Staff and the Applicant considered and made provisions for adequate margins of safety for the effects of settlement in conjunction with 1.5 x FSAR SSE ground motion forces.599 In addition, overburden and vehicular load effects were assessed relative to the margins of safety for existing Code criteria.600 341. The following strength criteria have been found .

acceptable by the NRC Staff:601 Criterion 1: 3S Sss c where S ss = stresses due to differen-tial soil settlement only.

In cases where Criterion 1 cannot be satisfied, the following three criteria must be met:

598 SSER #2, 9 3.9.3.1.3, p. 3-36.

599 All buried piping at the Midland plant has or will be analyzed using approved BC-TOP-4A techniques with the 1.5 X FSAR SSE earthquake as input. Lewis, Tr. 8941-8944; Affidavit of Dr. Thiru Thiruvengadam dated January 21, 1983, at p. 1.

See also Hendron, Tr. 3984-3986, for a discussion of under-ground pipe movement resulting from earthquake forces.

600 SSER #2, f 3.9.3.1.3, p. 3-36.

601 SSER #2, 5 3.9.3.1.3, pp. 3-36 to 3-37.

i

-232-Criterion 2: The total ovality due to a 1.5 x FSAR SSE plus soils settlement must be less than the maximum allowable ovality permitted for the diameter to-wall thickness ratio of the pipe. 692 Criterion 3: Sgg + Sg73 $ 1.5 S h where S 8b = stress due to sustained loads, as defined in the ASME Code; S gjg = stress loads; due to overburden S

h = basic material stress allowable at operating temperature, in psi.

Criterion 4: S 1.8 S OL h where S = stress due to occasional OL loads, as defined in the ASME Code, but also in-cluding bending or other stresses due to traffic loads.

(b) BUCKLING CRITERIA 342. " Buckling" is a deformation of a portion of the wall of a pipe. The buckling criteria discussed herein are intended to provide assurance that local buckling (which could lead to cracking in the pipe) and gross collapse (which could lead to loss of function of the pipe) will not occur, thus allowing the l pipe to perform its intended function throughout the life of the plant.603 343. Buckling data were obtained from theoretical and experimental sources available in the current technical litera-602 See paragraph 343, infra, for a discussion of ovality.

603 SSER #2, 5 39. 3.1.3, pp. 3-36 and 3-37; Chen & Hood, prepared testimony following Tr. 7762, at pp. 7, 10-12.

-233-ture. These data were reviewed in depth by the Staff and adapted for specifying buckling criteria for underground pip-ing. For this type of piping, the criteria are expressed specifically in terms of ovality and strain criteria. Ovality of a pipe is defined as:

Ovality =Dmax Dmin D

where D = outside diameter of unovalized pipe D

max = maximum outside diameter of ovalized pipe D

min = minimum outside diameter of ovalized pipe Based on these data, the allowable ovality adopted for the underground piping over the life of the plant is 4 percent for pipe with a diameter-to-wall thickness ratio of 69 and a factor of safety of 1.5.604 344. Where monitoring of pipe ovality is to be specified, the ovality will be determined by measuring pipe strains. A specific strain-to-ovality relationship has been developed by the Applicant and submitted to the Staff. This relationship is

! set forth in Figure 1 to the testimony of Donald F. Lewis.605 l

! For pipes with a diameter-to-thickness ratio of less than 69, the permissible maximum ovality under this relationship is j 604 See also Landers, SSER #2, 9 3.9.3.1.3, p. 3-37.

Lewis and Meisenheimer, prepared testimony at pp. 16, 21-25, following Tr. 7619.

605 l Lewis, prepared testimony at p. 3 and Figure 1, following Tr. 8868. See also SSER #2, 5 3.9.3.1.3, p. 3-37; l Landers, Lewis ad Meisenheimer, prepared testimony at pp.

j 24-26, following Tr. 7619.

l

-234-actually greater than 4 percent, but the Applicant has agreed to the 4 percent limit.606 (c) MINIMUM RATTLESPACE CRITERIA 345. A "rattlespace" is the space between the exterior of a pipe and the wall of a building or other structure which the pipe penetrates. The minimum rattlespace criteria discussed herein are intended to provide assurance that both local and gross overstressing of the piping and gross overstressing or distortion of piping components or attached equipment does not occur due to loads which may be imposed or are postulated to occur during the life of the plant.607 .

346. The clearance conditions of the piping at building or other structural penetrations are in part dependent on the proposed remedial actions for the associated piping in the plant fill and on the configuration of the piping at the pene-trations. These conditions are therefore quite variable and have required case-by-case study for their resolution.608 347. In general, assurance that minimum rattlespace will be adequate over the life of the plant has been provided by the analytical method set forth in section 3.9.3.1.3 of SSER #2 with respect to the 36-inch SWPS pipe penetrations. This 606 SSER #2, 6 3.9.3.1.3 p. 3-37.

607 SSER #2, S 3.9.3.1.3.

608 SSER #2, 6 3.9.3.1.3, pp. 3-37 and 3-38. See para-graphs 348-371, infra, for a discussion of the proposed reme-dial actions.

. . . . - . _ -_. .. , , . = _ - _ . . _ _ . ._.

l

-235-criterion requires that the minimum rattlespace shall be greater than or equal to 0.5 inch at all locations after taking into account variations in calculated pipe displacement due to future settlement or the effects of a 1.5 X FSAR SSE.609 II. SERVICE WATER PIPING (a) INTRODUCTION 348. To avoid confusion, the Licensing Board accepts the following definitions for terms used in these findings:

Replace - removal of existing buried pipe and the installation of new pipe.

Rebed - exposure of the existing buried pipe, removal of underlying fill, placement of new underlying fly ash concrete fill, realignment of the existing pipe, repairs to the pipe coating, and backfill around and over the pipe.

Reinstall - The ggglacing and/or rebedding of pip-Ing.

349. All of the 26 and 36 inch diameter SWS piping at the Midland plant was subjected to extensive profile and pipe ovalization measurement programs in November 1981. Profile data were obtained at 5 foot intervals along the pipe lengths and at welds, and are accurate to 1/16 inch. These 1981 data supersede the previously obtained 1979 data, which were accur-ate only to 1/4 inch. The 1981 data show that the piping is, 609 SSER #2, 9 3.9.3.1.3, p. 3-38.

610 See Lewis, prepared testimony at p. 9, following Tr.

8868.

-236-on the average, approximately 5 inches below its design eleva-tion, with deviations of up to 8 to 12 inches. The 1981 data also show that, in general, pipe ovalizations were between 1 and 1.5 percent, with a maximum of 3 percent.611 350. All the 8 and 10 inch SWS piping is located in the vicinity of the DGB.612 These lines were installed before the soils settlement problem was recognized, and they were in place during the DGB surcharge program. The lines were profiled in 1979, and the data indicated that they were, on the average, 6 to 8 inches below their design elevation, with a maximum devia-tion of up to 21 inches.613 351. The two longest SWS lines that exhibited the great'est deviations are located north of the DGB between the DGB and the Turbine Building. These lines were rebedded after the removal of the DGB surcharge. In addition, pipe diameter verification has been conducted on four 30-foot lines. The verification indicates that these lines are acceptable in accordance with American Waterworks Association (AWWA) requirements (i.e., less than 5 percent ovality), thus establishing that the DGB surcharge did not place excessive stress on the pipes. These rebedded 611 SSER #2, 6 3.9.3.1.1, p. 3-33. See also Landers, Lewis and Meisenheimer, prepared testimony at pp. 13-14, follow-ing Tr. 7619, for a description of the 1982 profiling. See SSER #2, $ 2.5.4.4.5, Figure 2.11, for a diagram of these pipes.

612 See SSER #2, $ 2.5.4.4.5, Figure 2.11, for a diagram of these pipes.

613 SSER #2, 9 3.9.3.1.1, pp. 3-33 to 3-34.

l

-237-and diameter-verified lines are presently disconnected at the bolted connections at or near their DGB penetrations.614 352. As will be discussed more fully below, the Applicant has committed to replace the 36-inch diameter SWS piping as a result of its inability to reach a resolution with the NRC Staff with respect to its adequacy.615 Following hearings in April, 1982, it was determined that it was also necessary to rebed a portion of the buried 26-inch diameter SWS piping as part of a fill replacement program to resolve potential lique-O faction concerns in the area north and west of the SWPS.

Because all the 36-inch diameter SWS pipe is located in this 1

area of potential liquefaction, it too will be rebedded during replacement.617 The following subsections of these findings will discuss the extent of the rebedding of the 26-inch diameter piping and the program for the reinstallation of the 36-inch diameter buried service water pipes.

(b) SCOPE OF THE REINSTALLATION PROGRAM 353. The reinstallation program proposed by Applicant and accepted by the NRC Staff includes the reinstallation of the buried 36-inch diameter service water system piping in the 614 SSER #2, 5 3.9.3.1.1, p. 3-34.

615 Lewis, prepared testimony at p. 8, following Tr. 8868.

See also Enclosure 2 to Applicant's letter dated March 16, 1982, Serial 16269, attached as Reference 2 to the Lewis testimony.

616 Lewis prepared testimony at p. 8, following Tr. 8868.

See also paragraphs 422 et seq., infra, for a discussion of liquefaction.

617 See SSER #2, 5 2.5.4.4.5, Figure 2.11, for a diagram of tluse pipes.

-238-vicinity of the service water pump structure and the rebedding of the two buried 26-inch diameter service water lines imme-diately north of the circulating water intake structure. The lines to be replaced are identified as:

36"-OHBC-15 36"-OHBC-16 36"-OHBC-19 36"-OHBC-20 These are the service water supply and return lines at the point of entry to and from the SWPS.618 354. The pipes to be rebedded are portions of lines 26"-OHBC-53 and 26"-OHBC-54. These are service water supply and return lines to and from the DGB and Turbine Building. The lines to be rebedded extend from the 36" lir.es to a point even with the southwest edge of the CWIS.019 (c) MATERIALS USED IN THE REINSTALLA-TION PROGRAM 355. The new fill material used to replace the potentially liquifiable fill in the area north of the SWPS and CWIS will be a type of low-strength fly ash concrete similar to the material known by the brand name "K-KRETE." The properties of this new l fill material will be similar to those set forth in Table 3 to the testimony of Applicant's witness Donald F. Lewis.620 These i

618 Lewis, prepared testimony at p. 10, following Tr.

j 8868.

l 619 Lewis, prepared testimony at p. 11, following Tr.

8868. See also SSER #2, l 2.5.4.4.5, Figure 2.11.

620 Lewis, prepared testimony following Tr. 8868, Table 3.

-239-properties will be verified by testing.621 This material will be placed to a level of 1 foot above the top of the pipe.622 356. The existing 36-inch diameter buried pipe will be replaced with 36-inch diameter welded ASME SA-672, Grade B-70, Class 20 pipe. The 0.625 inch nominal wall thickness will result in a diameter to thickness ratio of 57.6, considerably and acceptably reducing the potential for local buckling.623 357. The pipe is to be locally isolated from differential settlement caused by the transition from the old fill to the new low-strength fly ash concrete fill by encasing it in a 6 inch thick layer of a compressible polyethylene material known as "Ethafoam". The purpose of this material is to ensure that the pipe is effectively suspended at the transition from the old fill to the new fill, thus minimizing the effects of dif-ferential settlement.624 (d) REINSTALLATION PROCEDURE 358. The reinstallation of the designated SWS lines will be coordinated with the SWPS underpinning. The excavation 621 Lewis, prepared testimony at p. 11, following Tr.

8868.

622 SSER #2, 5 2.5.4.4.5, p. 2-36.

623 SSER #2, 6 3.9.3.1.3, p. 3-38; Lewis, prepared testi-mony at p. 11, following Tr. 8868.

624 SSER #2, $$ 2.5.4.4.5, 3.9.3.1.3, pp. 2-36 to 2-37, 3-39; Lewis, prepared testimony at p. 12 and Figure 4, follow-ing Tr. 8868. See also Affidavit of Dr. Palanichamy Shunmugavel on Ethafoam, dated August 2, 1983.

-240-required to expose these lines and replace unsuitable fill will be contiguous with the excavation for the SWPS underpinning.625 359. Underground pipelines that will be exposed during excavation work will be left in place, and temporarily support-ed and protected to preclude damage.626 Precautions will include, as necessary, such measures as:

a) shoring and bracing supporting fill; b) complete temporary support; c) staking utility locations prior to excavation; and d) hand excavation near utilities.627 .

A list of structures, facilities, and utilities that may be encountered or affected by the excavation is included in Table 5 to the testimony of Applicant's witness Donald F. Lewis.628 360. Fill material within limits agreed to between Appli-cant and the NRC Staff 629 will be excavated down to elevation 610 and replaced with a suitable material to minimize settlement l

and prevent liquefaction. Predicted future settlement, consider-625 Lewis, prepared testimony at p. 14, following Tr.

8868. See paragraphs 245 et seq., supra, for a discussion of the SWPS underpinning.

626 Lewis, prepared testimony at p. 14, following Tr.

8868.

627 l Lewis, prepared testimony at p. 14, following Tr.

l 8868.

628 Lewis, prepared testimony following Tr. 8868, Table 5.

629 Lewis, prepared testimony following Tr. 8868, Figure 4.

-241-ing replacement of loose or soft fill material, is not expected to exceed 1.5 inches, a figure less than the 3.0 inches of settlement estimated for the existing fill. This fill replace-ment therefore reduces the adverse affects of differential soils settlement.630 361. The 26-inch pipe to be rebedded will, at a minimum, be exposed from the point where it connects to the 36-inch line to a point approximately even with the southwest edge of the CWIS. The existing 36-inch pipe to be replaced will be cut from the point where it connects to the 26-inch pipe and at a point inside the SWPS near the penetration.631 Any 36-inch pipe which has already been replaced and temporarily covered-will again be exposed.632 The soil beneath all the pipes, within the limits referenced in paragraph 360, supra, will be removed and replaced with the fly ash concrete discussed in paragraph 355, supra.633 Before being rebedded, the pipe will be inspected to verify the integrity of the pipe and the exter-630 SSER #2, pp. 2-36, 3-39; Lewis, prepared testimony at p.11, following Tr. 8868.

631 Lewis, prepared testimony at p. 15, following Tr.

8868. See SSER #2, 9 2.5.4.4.5, Figure 2.11, for a diagram of these pipes.

632 Because of Applicant's need for the 36-inch pipe in meeting its startup test schedules, portions of this pipe may l

be replaced, and then temporarily backfilled for frost protec-tion. See Lewis, prepared testimony at p. 15, following Tr.

8868.

633 Lewis, prepared testimony at p. 15, following Tr.

8868.

l

2 -242-4 nal corrosion coating,634 and then encased in compressible ;

material where applicable.635 362. All pipe will be fabricated and installed in accor-dance with design drawings and specifications and in accordance with the Work Authorization Procedure established by this Board in our April 30, 1982 Order.636 All material used to replace

unsuitable fill and to backfill the excavation will be placed i

in accordance with design drawings and specifications.637 I (e) APPLICANT'S ASME ANALYSIS OF THE I REINSTALLED PIPE l 363. The Applicant has performed dynamic seismic analyses of the buried SWS piping which has been or will be reinstalled.638

. These analyses, performed using Bechtel Associates' ME-101 computer code,639 analyzed the piping for appropriate ASME load 634 Lewis, prepared testimony at p. 15, following Tr.

i 8868. The anti-corrosion coating is discussed at paragraphs 384-385, infra.

635 Lewis, prepared testimony at p. 15, following Tr. 8868.

636 Memorandum and Order (Imposing Certain Interim Condi-tions Pending Issuance of Partial Initial Decision), LBP-82-35, l 15 N.R.C. 1060. See also Bird and Wheeler, prepared testimony on NRC #Mol-4-2-008 (Rev. 1), NRC #Mol-9-2-038, NRC #Mol-9-2-51, Bechtel NRC #4199 (including stop-work order FSW-22), and Bechtel NRC #4245 (hereinafter " prepared testimony on nonconformance re-ports concerning drilling incidents") at p. 9, following Tr. 11408.

637 l Lewis, prepared testimony at pp. 15-16, following Tr.

! 8868.

638 See Lewis, prepared testimony at pp. 12-14 and Table 4, following Tr. 8868; Affidavit of Thiru R. Thiruvengadam dated January 21, 1963.

i 639 Lewis, prepared testimony at p. 12, following Tr.

8868; Affidavit of Thiru R. Thiruvengadam dated January 21, 1983. Bechtel computer program ME-101 is described in FSAR Section 3.9.1.2.

-243-combinations and certain single point settlement stresses.

ASME Code Equations 8, 9, and 10 and Code Case 1606-1, which were utilized by Applicant in the analyses, address stresses due to design and peak pressure, weight and sustained loads '

(including overburden), seismic inertial loads, thermal expan-sion and seismic anchor movements. The ME-101 analysis incor-porated the FSAR SSE as input.640 364. The Applicant is also in the process of performing a check analysis on the buried SWS piping which has been or will be installed, using approved BC-TOP-4A techniques. This check analysis uses the 1.5 X FSAR SSE as input. For purposes of the BC-TOP-4A analysis, the 1.5 X FSAR SSE response spectra enve-lopes the SSRS, because it results in greater seismic forces.041 In addition, Applicant's Seismic Margin Review will include Seismic Category I underground piping.642 III. DIESEL FUEL PIPING 365. The diesel fuel oil lines were installed in June of l 1980 after completion of the Diesel Generator Building sur-charge program. They are attached to unistrut support frames l

640 Lewis, prepared testimony at p. 12, following Tr.

8868; Lewis, Tr. 8941-8943. Even though the FSAR SSE (0.129) earthquake was used in this analysis, the input spectra actually was more conservative than the SSRS. See Affidavit of Thiru R.

Thiruvengadam dated January 21, 1983.

641 Lewis, prepared testimony, Sheet 2 of Enclosure 2 of Table 4, following Tr. 8868; Lewis, Tr. 8941-8944; Affidavit of Thiru R. Thiruvengadam dated January 21, 1983.

See Philip P. Steptoe letter to Administrative Judges dated February 3, 1983, Enclosure A.

-244-embedded in concrete piers, which are located at approximately 20-foot intervals. Both piping and supports are covered with approximately 2 feet of compacted fill and are to be provided with tornado-missile protection.643 366. The maximum settlement stress of the diesel fuel piping has been calculated assuming that the maximum value of three inches of predicted settlement was apportioned over a span of pipe corresponding to the maximum spacing between pipe footings. The highest calculated stress value is 18 ksi. This value is well within the allowable stress of 45 ksi for these lines under the 1977 ASME Code.644 Further, the pipes will settle with the diesel oil storage tanks, and thus the dif ferential settlement between the pipes and tanks will be small.656 367. The Licensing Board finds that this flexible small diameter pipe in the diesel fuel lines can safely accomodate future plant fill settlement.

IV. BORATED WATER PIPING 368. Profile data obtained in 1979 and 1981 show that these lines are below their design elevation by up to 2 inches, the maximum deviation allowed for under the construction toler-ances. However, with the exception of the portions of the 643 SSER #2, 9 3.9.3.1.1, p. 3-34.

644 Landers, Lewis and Meicenheimer, prepared testimony at p. 11, following Tr. 7619.

645 Landers, Lewis and Meisenheimer, prepared testimony at p. 11, following Tr. 7619.

-245-lines discussed below, the differential settlement effects for these lines have been evaluated, and the NRC Staff has found the effects of past and future settlement to be acceptable.646 369. The portions of the four 18-inch diameter borated water lines from the Borated Water Storage Tank valve pits to the dike wall around the outdoor tanks will be rebedded. These lines have been cut loose from the valve pits to isolate them from settlement caused by the surcharge of the valve pits, and have been refitted and recentered in the valve pit penetrations.

This partial rebedding and recentering in conjunction with the existing program to monitor future settlement of the Borated i Water Storage Tanks and the Auxiliary Building will provide '

sufficient assurance of the continued serviceability of this piping.647 V. CONTROL ROOM PRESSURIZATION LINES 370. These lines were installed in 1981, after major fill settlements had occurred and in a manner equivalent to that utilized for the rebedding of other piping. The future dif-646 SSER #2, S 3.9.3.1.1, p. 3-34.

647 SSER #2, S 3.9.3.1.4, p. 3-40; Landers, Lewis and Meisenheimer, prepared testimony at p. 12, following Tr. 7619.

Stress analyses based on the profile data for these lines satisfy the criterion accepted by the Staff. However, monitor-ing programs are to be implemented at the ends of the piping to address rattlespace concerns. Pipe strain only will be moni-tored at the valve pit penetrations. Pipe strain and minimum rattlespace dimension will be monitored at the auxiliary build-ing penetrations. The maximum additional ovality and minimum rattlespace dimension will be limited to four percent and 0.5 inch, respectively, throughout the life of the plant. The current minimum rattlespace dimension at any penetration is 1-7/8 inches. SSER #2, S 3.9.3.1.4, p. 3-40.

-246-ferential settlement effects are expected to be negligible.

Therefore, the Licensing Board finds that there is reasonable assurance of continued serviceability of the pipes in this system.648 VI. PENETRATION PRESSURIZATION LINES 1

371. These lines had not been installed as of November, 1982 (the month during which the latest hearing on buried piping was held.) Because the majority of fill settlement will already have occured before these pipes are installed, the Licensing Board finds that the effects of differential settle-ment will be negligible, and that there is reasonable assurance of continued serviceability of the pipes in this system.649 VII. THE MONITORING PROGRAM (a) STRAIN GAUGE MONITORING 372. The effect of future soil settlement on the SWS piping will be monitored using externally mounted strain gauge instruments located at various points along the piping system.650 s-648 #2, 5 3.9.3.1.1, p. 3-24; Landers, Lewis and 93k MeiserJu *er prepared testimony at p. 12, following Tr. 7619.

64p See GSER #2, S 3.9.3.1.1, p. 3-34.

650 SSER #2, $ 3.9.3.1.3, p. 3-39; Landers, Lewis and Meisenheimer, prepared testimony at p. 33, following Tr. 7619.

The SWS piping is to be monitored by strain guages because it is the most critical piping in terms of its response to soil settlement, and because of tts necessity of the strain mea-surements in computing ovality. See Lewis, Tr. 7673; paragraph 344, supra.

-247-373. A curved erived theoretically is used to determine the equivalent strains for the allowable ovality and the actual ovality data measured on the Midland 26-inch diameter SWS piping.651 Allowable ovality for the pipe is 4 percent, which is equivalent to 0.0048 inch / inch strain and which includes an appropriate safety factor, as discussed in paragraphs 342-344, supra. Using the curve, the ovalization data measured in the 26-inch diameter pipe is transformed to an equivalent strain.

This equivalent strain value is subtracted from the allowable strain to determine the future maxima for the strain monitoring stations.

374. Table 1 to the Lewis testimony shows the measured '

ovality, corresponding meridional strain, and future allowable strain for all strain monitoring stations on the buried Midland Seismic Category I piping. The method used to calculate the future allowable strain allows the pipe strain resulting from soil settlement occurring before the 1981. data to be accounted for at each station. Table 1 to the Lewis testimony also specifies the number of strain gauges for each monitoring station. The number of gauges were determined by reviewing the pipe elevation profiles for abrupt inflection points and criti-cal buckling zones. Each such station includes at least two gauges, thus providing redundancy. The strain gauges are to be mounted one pipe diameter apart along the top line of each 651 Lewis, prepared testimony at p. 4 and Figure 1, following Tr. 8868; Lewis, Tr. 7697.

-248-pipe.652 The strain guages are of a type that is known to be These gauges will be trouble-free for twenty years or more. 653 monitored to insure that they are functioning correctly.

(b) VERTICAL SETTLEMENT MARKERS 375. Vertical settlement markers have been added to various monitoring stations to supplement the pipe strain gauge These markers have been installed where loosely measurements.

based on borings taken throughout the compacted anil may exist, plant site fill material, and where high future differential settlement could potentially occur due to underlying utilities.

Figure 2 to the testimony of Mr. Lewis is a monitoring station location diagram for both strain gauge monitors and settlement markers. Figure 3 to the Lewis testimony shows a typical pipe settlement marter which will be attached directly to the pipe.654 376. The vertical settlement measurements are to be based This upon the initial installation survey of the markers.

Subsequent surveys survey will establish an elevation datum.

will be compared against this datum to calculate the pipe move-ments.

The differential vertical displacement from the initial 652 Lewis, prepared testimony at p. 4, Figure 1 and Table 1, following Tr. 8868; Chen, Tr. 9023-9024; Kane, Tr.

9023.

653 Lewis, Tr. 7704; Kane, Tr. 7794; Kane, Tr. 7763-7764.

654 Lewis, prepared testimony at p. 5, Figure 2 and Figure 3, following Tr. 8868.

1 I

l

-249-datum to the current survey measurement will be used for compari-son to the acceptance criterion discussed in paragraph 379, infra. This acceptance criterion is based on the prediction of three inches of predicted maximum future settlement.655 377. The vertical settlement markers measure the absolute pipe settlement at each monitoring station, rather than the differential settlement between stations. If any one station reaches or exceeds the acceptance criterion discussed in para-graph 379, infra, an investigation will be called for under the proposed Technical Specifications. The combination of strain gauges and settlement markers at each monitoring station will ensure that differential settlement will be detected and proper actions taken before stresses exceed the allowable limits.656 (c) STRAIN AND SETTLEMENT MONITOR-ING FREQUENCY 378. The measuring frequency for the monitoring stations will be the same for both strain gauges and vertical settlement markers. Monitoring will commence after the gauges and markers are installed and operational. The monitoring schedule that has been submitted is as follows:

1. At least once each 30 days during the first 6 months of unit operation. The frequency will continue until observed settlement has stabilized at less than or equal to 0.10 inches from the pre- -

vious reading.

655 Lewis, prepared testimony at p. 5, following Tr.

8868.

656 See Lewis, Tr. 8869-8872.

. - - - - =. - , -

-250-

2. When observed settlement stabilizes as discussed in (1), above, the monitoring frequency will decrease to at least once each 90 days during the first 5 years of plant operation for all stations. After the fifth year, Applicant will file a report with the NRC on the need to continue monitoring of the field stations. This report will be based upon the evaluation of time history plots of the collected data.

3. After the fifth year of plant opera-tion, anchor stations will be monitor-ed on a yearly basis for the remaining plant operating life.

4. In the event of an unusual event, the Applicant will immediately monitor all stations.

5. In the event of a reportable occurrence, -

the Applicant will increase monitoring frequency as is determined ne by the Applicant and the NRC.gg9sary (d) PROPOSED TECHNICAL SPECIFICATION ACCEPTANCE CRITERIA AND ACTIONS 379. Under Applicant's proposed Technical Specifications, if either the future allowable strain specified in Table 1 to the Lewis testimony or 75 percent of the three inch vertical settlement criteria is reached, this will constitute a report-l able occurence. Increased monitoring frequency will thereafter be required, the NRC will be notified of the occurrence and an engineering evaluation of the situation will be initiated.

Supplemental reports to the NRC will follow the initial notifi-cation to describe the final resolution and actions. Such l

657 Lewis, prepared testimony at pp. 7-8, following Tr.

8868. See also Lewis, Tr. 8873-8875.

l

-251-actions may include excavation of piping in the affected zone for visual examination and possible replacement or sleeving.

Strain gauges which are determined to be providing faulty data will be recalibrated or replaced within ninety days during the first five years of monitoring.658 (e) RATTLESPACE MONITORING 380. The clearances of piping penetrations into buildings where the pipes involved have not been rebedded and re-analyzed will be monitored to assure continuing adequate rattlespace clearance. As required by the minimum rattlespace criteria discussed in paragraphs 345-347, supra, the soil settlement,-

seismic, and thermal displacements will be combined and com-pared to the available annular space to insure at least a 0.5 inch safety margin. The rattlespaces will be monitored on a yearly basis for the first five years of plant operation. A determination will then be made as to the necessity of con-tinued monitoring.659 (f) LAYDOWN LOADS AND SAFETY GRADE UTILITIES 381. Load limits have been specified to prevent a surcharg-

! ing effect resulting from laydown loads of long term storage over buried safety grade piping and conduits. Exclusion zones 658 Lewis, prepared testimony at p. 5, following Tr.

8868.

659 Lewis, prepared testimony at p. 7, following Tr.

8868.

l l

-252-l will be used to designate the affected safety grade utility and the maximum allowable loads and time limits. Applicant's witness Lewis sponsored Table 2, attached to his prepared testimony, which proposes Technical Specification limits to be submitted in the FSAR. The basis for the specified limits is an allowable surcharge settlement of 0.5 inches at a depth of 7 feet below the ground surface -- the average buried pipe depth.

The control procedure to administer this program will be handled in conjunction with the plant operating procedures for control-ling heavy loads inside the plant.660 VIII. FREEZEWALL CONCERNS 382. The Applicant has committed to providing a plan for addressing a Staff conce'.n about differential settlement that arises from a modification to Applicant's originally proposed freezewall crossing design. The freezewall is a temporary underground barrier of frozen earth created for construction purposes to minimize groundwater flowing into the areas where underpinning excavations for the control tower, electrical penetration areas, and the feedwater isolation valve pit are taking place. There is a potential for differential settle-ments where piping or conduit crosses the freezewall. Applicant will submit information that describes the crossing modifica-tion, details on surcharging the piping and conduit foundations during ground freezing, and the monitoring records on heave 660 Lewis, prepared testimony at pp. 7-8, following Tr.

8868.

-253-and/or settlement. Details on backfilling the excavations at the freezewall crossings will also be provided by the Applicant.661 E. CORROSION I. INTRODUCTION 383. At the OM-OL hearings held before this Board on February 18, 1982, intervenor Stamiris introduced Stamiris Exhibit 35. This exhibit indicates that pitting corrosion had been discovered with respect to a portion of the non-safety related stainless steel condensate storage tank piping.662 While the Board has not been presented with any specific conten-tion relating to corrosion of underground piping, we directed the NRC Staff to provide a witness on the issue.663 In response to our request, the Staff submitted the testimony of Dr. John R.

Weeks, a Senior Metallurgist at Brookhaven National Laboratory.664 II. PROTECTION OF UNDERGROUND PIPING FROM EXTERNAL CORROSION 384. All carbon steel piping used in the service water and diesel fuel lines is protected from corrosion by a combination 661 SSER #2, 9 2.5.4.4.5, p. 2-36.

662 See Stamiris Ex. 35; Hood, Tr. 7827-7828. Exhibit 35 was admitted subject to the qualification that certain hand-written notes on the face of the document had not been authenti-cated and were not to be regarded as evidence. Tr. 7836-7837.

663 Tr. 7835-7836, 8980.

664 Mr. Weeks prepared and sponsored SSER #2, 5 3.12.

Weeks, Tr. 9148. See also Lewis, prepared testimony, section 5.0, following Tr. 8868.

-254-of a primer paint and a protective wrapping to provide elec-trical insulation as well as a physical barrier between the piping and the corrosive environment. There are procedures for both shop coating of piping and field coating of field welds to ensure that this piping will be protected from external corro-sion. In addition, the piping has been 100 percent inspected by Bechtel for defects in the coating. Bechtel inspectors have determined that the coatings are acceptable.665 385. The buried pipe wrapping material consists of rein-forced fiberglass followed by a layer of coal tar saturated felt paper wrap for the shop coated material, and by a field installed tape coat for the field coated material. Both tech-niques are standard commercial practices for protecting carbon steel piping from groundwater attack. Field installation and backfill techniques were carefully specified to minimize damage to the coatings. These procedures were also monitored by the Bechtel quality assurance department. An independent check of the condition of the pipe wrappings will be performed when the 36-inch pipes are excavated and replaced before startup of the plant.666 l 386. The entire Midland site is protected by a galvanic protection system designed to maintain all buried piping to a potential of 0.85 V negative to the copper / copper sulfate j reference electrode. This is a standard industry practice 665 SSER #2, S 3.12.1, p. 3-42; Lewis, Tr. 8877, 8882-84.

Enclosures:

(1) QA Topical Report (Cha r*:)

(2) QA Topical Report (Char:)

(3) QA Department Procedure (4) QA Chart dated 1/22/82 i

CPCo 22 12/14/81 Audit CPCo Bechtel QC inspector train- 6937 6940 2/ 2/82 Report ing program 11/2-6/81 Attachments:

a (1) Audit observations (2) Audit checklists

1 i.

i l

Midland OM/OL Hearings

)

Exhibits 1

2 IDENTI- IN EVI- DATE

! DATE OF FIED AT DENCE IN i DOCUMENT DOCUMENT PROM TO SUBJECT TR. AT TR. EVIDENCE

} EXHIBIT i

! CPCo 23 7/24/81 Audit CPCo Bechtel OC inspector train- 6937 6940 2/ 2/82 t Report ing 7

6/2-7/3/81 i Attachments:

) (1) Audit Finding Reports (2) 10/29/81 Letter Turnbull to Bechtel re: U.are-solved Items i

' (3) 10/15/81 Letter Turn-

bull to Dechtel re:

I unresolved Item 03 (4) 10/9/81 Letter Bechtel to Turnbull re: URI's.

. CPCo 24 2/ 1/82 Lette r Miller Board Hold point testimony of BWM 7120 7122 2/ 2/82 subject to misinterpretation

}

CPCo 25 Group of Response to Harbour question 7939 7946 2/19/82 1 Dorinq Loqs re: what the rotation or tor-and Charts sion of DWST valve pit would be if racking occurred.

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J Midland OM/OL Hearings Exhibits I

IDENTI- IN EVI- DATE DATE OF FIED AT DENCE IN EXHIBIT DOCUMENT DOCUMENT FROM TO SUBJECT TR. AT TR. EVIDENCE CPCo 26 Hendron 9627 8628 11/15/82 drawing

?

CPCo 27 Drawing Aux. Bldg. deflection 9428 9428 11/18/82 CPCo 28 Drawing SWPS 9541 9541 11/19/82 CPCo 29 (R) Drawing DGB Crack 11070 11073 12/10/83 monitoring '

1 CPCo 30 Report Matra (NRC) DGB Structural Reanalysis 11126 11128 12/10/82 CPCo 31 Calculation BPCo OBS-4 11752 11752 2/16/83 sheet

) CPCo 32 3/28/83 Savage Dep Savage Steam Generator 14111 Relevant por-4 tions desig-i nated in Appli- #

cant's letter to

! the Licensing 1

Board, dated 4/12/83, and in the NRC Staff's

, letter to the Licensing Board, ,

dated 5/13/83 !

! CPCo 33 Report S&W Independent Assessment of 15581 17344 6/17/83 4

Underpinning: 90 day re-port (green binder) t

Midland OM/OL Hearings Exhibits IDENTI- IN EVI- DATE DATE OF FIED AT DENCE IN EXHIBIT DOCUMENT DOCUMENT FROM TO SUBJECT TR. AT TR. EVIDENCE CPCo 34 9/9/82 Resume Meisenheimer J. Meisenheimer qualifi- 15589 Not in cations evidence CPCo 35 4/13/83 Bargraph Sucharski Noncompliances for Reg. III 16231 16285 5/ 6/83 f R. III Plants under construction CPCo 36 11/19/82 Memo Smith CQCE QC position or inspections 16267 Withdrawn:

(Bechtel QC) and documentation of defi- 16288 ciencies: recommend use of IPINs and/or NCRS.

CPCo 37 12/ 2/82 Letter Curland Smith See Ex. 36. Use of IPINs to 16275 Withdrawn:

(Dechtel AC) be eliminated. 16288 CPCo 38 1/26/83 Letter Wells Rutgers Elimination of use of IPINS 16280 withdrawn:

16288 CPCo 39 FSAR Palo Verde Drawing from Palo Verde 16392 Not in Drawing PSAR Fig. 2.5-76 Amend 7 evidence CPCo 40 FSAR Byron Byron and Raidwood FSAR 16400 Not in Drawing Draidwood Fig. 3.8-45 evidence J

_ m , _ . _ . ~ . . . . _ . . . . .

_ _ . . _ . . _ . . _..-m_ .. . . . _ . . _ - _ _ . . . .. . . - .- ._ . . . . .

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3, l Midland OM/0L Hearings Exhibits 2

IDENTI- IN EVI- DATE DATE OF FIED AT DENCE IN EXHIBIT DOCUMENT DOCUMENT PROM TO SUBJECT TR. AT TR. EVIDENCE 1

CPCo 41 Figure, 4 pp. South Texas South Texas Project -- 16401 Not in Fig. 1.3-1 evidence

, o j CPCo 42 50.54(f) CPCo Q1 and 023 (portions) 16415 Not in Response evidence *

(portion)

CPCo 4 3 Figure -Monticello Monticello FSAR fig., 16435 Not in j describes a structure evidence

, using spread footing foundation on compacted fill.

CPCo 44 6/ 4/83 5/ 6/83 Letter D.B. Miller NRC/ Revision 6 to MPQP-1 16978 17013

! Itarrison CPCo 45 4/ 6/82 Notes Weil April 6 Interview with 17716 17959 6/10/83

} Landsman; includes j Landsman's notes from i either 4/6 or 3/10.

CPCo 46 Organizatien Wells MPQAD 18015 18024 6/27/83 j Chart 1

CPCo 47 Memo Iferzer Rutgers Clarify MPQAD's assump- 18020 18024 6/27/83 (Bechtel's tion of QC tasks.

4 Midland Site Ma r. )

i 1

a b , -,

. . . ~ . . - . . .- -

Midland OM/OL Hearings Exhibits IDENTI- IN EVI- DATE DATE OF FIED AT DENCE IN DOCUMENT DOCUMENT FROM TO SUBJECT TR. AT TR. EVIDENCE EXHIBIT CPCo 48 6/10/83 Letter CPCo NRC Describes current status 18021 18024 6/27/83 of documentation re: CCP CPCo 49 6/24/83 Letter Cook NRC Additional info requested 18922 18926 6/30/83 on response to N.O.V.

J I

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I 4 Midland OM/OL Hearings Exhibits

)

< DATE OF IDENTIFIED IN EVIDENCE DATE IN EXHIBIT DOCUMENT DOCUMENT FROM TO SUBJECT AT TR. AT TR. EVIDENCE !

Holt 1 -

SSRS Proposed Midland SSRS 4540 4540 10/13/81 .

(CPCo Witness) rigure 1.2 for original ground surface (modified at

longer periods), 5%

] critically damped Holt 2 -

SSRC 84th percentile SSPS 4540 4540 1C/13/81 (CPCo Witness) Figure 7 for top of fill material and design spectrum for Midland, 54 critically damped

. Holt 3 10/14/80 Letter Tedesco J. Cook Seismological input for 4540 4540 10/13/81 (CPCo Witness) Midland i Holt 4 1931 Article in Wood & Modified Mercalli 4540 4540 10/13/81 (CPCo Witness) Bulletin of Neumann Intensity Scale

! Seisnological i Soc. of America Holt 5 2/81 Report Weston CPCo Midland SSRS, Part I: 4540 4540 10/13/81 i

(CPCo Witness)

Geo- Response Spectra-SSE physical Original Ground Surface Holt 6 6/81 Report Weston CPCo Midland SSRS, Addendum 4540 4540 10/13/81 1 (CPCo Witness) Geo- to Part I physical 4 ,

i !

1

Midland OM/OL IIcarings Exhibits DATE OF EXHIDIT DOCUMENT DOCUMENT FROM TO SUDJECT IDENTIFIED Ifi EVIDENCE DATE IN AT TR. AT TR. EVIDENCE Holt 7 7/81 Report Weston CPCo Dasis for Rejection of (CPCo Witness) Geo- ,4540 4540 10/13/81 physical 1966 Parkfield Earthquake Accelirograms for use in Midland SSRS .

Ilolt 8 4/81 Report Weston CPCo (CPCo Witness) Midland SSRS, Part II: 4540 Geo- 4540 10/13/81 physical Response Spectra Appli-cable for the Top of Plant Fill Material Holt 9 2/81 Report Weston CPCo (CPCo Witness) Midlano SSRS, Part III: 4540 Geo- 4540 10/13/81 physical Seismic liarard Analysis flol t 10 -

Typed (CPCo Witness) Summary of Applicant's 4551 4551 S umma r)

Position with respect to 10/13/81 w/ attached Figs. 1-5 Midland SSRS (summary of the fo mal probabalistic analysis in Ifolt Ex. 9)

Ifolt 11 -

SSRS (CPCo Witness) 84th percentile SSRS for 5117 Figure 7 top of fill material and 5118 10/15/81 (modified) design spectrum for Midland.

5% critically damped.

(Identical to Ifolt Ex. 2, expect response spectra modified in low frequency and to coincide wi*h Mid-land design spectrum, i.e.,

FSAft spectrum)

4 i

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Midland OM/OL Hearings Exhibits 1

l DATE OF IDENTIFIED IN EVIDENCE DATE IN t EXHIBIT DOCUMENT DOCUMENT FROM TO SUBJECT AT TR. AT TR. EVIDENCE i

i Stamiris 1 12/4/78 Memo Keeley/ File DGB settlement meeting 1516 1518 7/10/81

T.C.Cooke i

A Stamiris 2 7/9/80 Audit Finding Horn 1461 1463 7/9/81 Report 3177 8/5/81 m (Entered Twice) i j Stamiris 3 7/11/81 NRC Staff OA Program Implementation 1770 2479 7/15/81 l Testimony Prior to 12/6/79

(Gallagher) i 4 Stamiris 3 9/29/78 Initial CPCo Keppler DGB settlement i Attachment 50.50(e) 1 Report j Stamiris 3 11/17/78 I&E 78-12 NRC DGB settlement, etc.

Attachment j 2 i

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l Midland OM/OL Hearings Exhibits DATE OF IDENTIFIED IN EVIDENCE DATE IN EXHIBIT DOCUMENT DOCUMENT FROM TO SUBJECT AT TR. AT TR. EVIDENCE Stamiris 3 1/12/79 Summary of Hood Structural settlements Attachment 3 12/4/78 ,

Stamiris 3 2/23/79 NRC Presenta- DGB Settlement and Plant Attachment 4 tion of Prelim. Area Fill Investigation Findings of DGB Settlement Stamiris 3 3/9/79 CPCo Discussion Attachment 5 of NRC Inspect-ion Facts re-sulting from DGB Investigation Stamiris 3 3/21/79 50.54(f) Denton Howell Plant Fill Inquiry Attachment 6 Request Stamiris 3 3/22/79 I6E 78-20 DGB settlement and adequacy Attachment 7 of plant area fill Stamiris 3 4/9/79 IEE 79-06 Soil boring program and Attachment 8 plant area fill settlement monitoring Stmairis 3 4/24/79 CPCo Response CPCo NRC OA Attachment 9 to 50.54(f)

Question 1

. .~ ._ -- _ - - - - - . . ..

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i Midland OM/OL Hearings Exhibits l

Il DATE OF IDENTIFIED IN EVIDENCE DATE IN l

EXHIBIT DOCUMENT DOCUMENT FROM TO SUBJECT AT TR. AT TR. EVIDNECE i

j Stamiris 3 6/6/79 I6E 79-10 Failure to properly trans-Attachment 10 late PSAR design requirements into specs and procedures Stamiris 3 8/10/79 Bechtel Review Attachment 11 of US Testing Field & Lab Tests on Soils i

! Stamiris 3 10/1/79 I6E 79-19 Inadequate design control j Attachment 12 inadequate OA personnel qualifications Stmairis 3 10/16/79 Summary of Hood Soil deficiencies j Attachment 13 7/18/79 Meeting i Stamiris 3 11/13/79 CPCo Response CPCo NRC Supplement request for Attachment 14 to 50.54(f) additional soils i Ouestion 23 settlement information

! Stamiris 3 12/6/79 Order NRC CPCo Modifies Construction Attachment 15 Permits 1

Stamiris 3 4/16/80 CPCo Answer j Attachment 16 to Notice of j Hearing 4

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. . _ - . . _ . . .- . . - . - - -. . . . - - . -_. - - . . .- . ~ . . - - _ .

i l

Midland OM/OL Hearings Exhibits l DATE OF IDENTIFIED IN EVIDENCE DATE IN EXHIBIT DOCUMENT DOCUMENT FROM TO SUBJECT AT TR. AT TR. EVIDENCE l

1 l Stamiris 3 Professional Attachment 17 Qualifications j of Gallagher i !

Stamiris 4 5/26/81 Letter Stamiris Keppler Attachments: (1) 11/26/73 "OA 2192 Wdwn:

Deficiencies"; (2) 4/6/81 2196 a 1 Intervenor's Answer Opposing j CPCo Motion; (3) 7/9/80 " Plan-4 ning Peports"; (4) 8/8/80 l "Mgmt. Corrective Action Request."

Stemiris 5 8/13/69; PSAR CPCo; NRC; Dames & Moore Report Amendment: 2486 To remain 3/15/69 Amendment Dames & Bechtel pp. 1, 9, 10, 11, and page in ID form No. 3 Moore entitled, "NRC Prelim. 2524 i (Dames & Moore Finding 4."

Report)

Stamiris 6 9/28/78 Meeting notes Afifi Settlements or structures south 2532 2538 7/16/81 of the lurbine building which are founded on fill i Stamiris 7 12/4/78 Bechtel D. Dhar CPCo-NRC-Dechtel meeting re 2829 2831 8/4/81 Meeting Notes DGB and other settlements.

?

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1 4 Midland OM/OL Hearings l Exhibits

,)

DATE OF IDENTIFIED IN EVIDENCE DATE IN EXHIBIT DOCUMENT DOCUMENT FROM TO SUBJECT AT TR. AT TR. EVIDENCE Stamiris 8 11/1/78 Notes of Dunnicliff File Status - DGB 2874 Not in

, 10/18/78 (Soil & Instrumentation Evidence

meeting Rock Instr.)

l_

Stamiris 8A Map of DGB Attached to Stamiris 8 3436 Wdwn:

1 soil instr. 3923 1 locations

, Stamiris 9 10/18/78 10/18/78 Marshall File Site visit by John Dunnicliff 2876 Not in l

Meeting Notes (Bechtel) Evidence

i 11/6/78 10/18/78 meeting and planned 2885 Stamiris 10 Memo Marshall Afifi Not in (Bechtel) DGB surcharge instrumentation Evidence

Stamiris 11 11/7/78 Letter Howell Keppler Transmits interim 50.55(e) 2891 2892 8/4/81 report on DGB settlement Stamiris 12 8/11/80 MCARR CPCo Report No. HPL-1 2918 2924 8/4/81 8/11/80 (Mgmt. re: Part 21 report on Corrective pipe whip restraints Action Dequest/

Repor t)

Still open as of end of 8/4/81.

1 4

4

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Midland OM/OL Hearings Exhibits 4

i DATE OF IDENTIFIED IN EVIDENCE DATE IN EXHIBIT DOCUMENT DOCUMENT FROM TO SUBJECT AT TR. AT TR. EVIDENCE

{

! Stamiris 13 11/1/78 Letter Martinez Keeley Confirming 10/25/78 meeting 3254 3372 8/6/81 (Dechtel) re: continuation of work on 1 DGB pending final decision on remedial measures Stamiris 14 12/20/79 Memo Beloff Afifi Validity of Sondex readings 3255 3266 3/6/81

(Soil &

Rock Instru-mentation)

Stamiris 15 10/18/78 Letter Peck Afifi confirming 11/6/78 arrival 3286 3372 8/6/81 I j

in Urbana, and question re:

reliability of brine-field

. subsidence data in FSAR j Stamiris 16 11/6/78 Handwritten Meeting in Champaign 3356 Not in

Meeting Notes Evidence

! Stamiris 17 Response to CPCo NRC DGB Prelead 3405 3405 8/7/81 i 50.54(f)

Question 21 l

I Stamiris 18 12/15/78 Memo Peck File 12/8/78 consultant meeting 3406 3429 8/7/81 re: DGB surcharge program

}

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Midland OM/OL Hearings Exhibits DATE OF IDENTIFIED IN EVIDENCE DATE IN EXHIBIT DOCUMENT DOCUMENT PROM TO SUBJECT AT TR. AT TR. EVIDENCE I Stamiris 19 9/29-30/77 Boring Log Hole No. D at DGB 3437 4339 S/13/81 Stamiris 20 10/8/78 Meeting Notes Afifi File 10/8/78 Meeting with 4008 4041 8/11/81

+ (Early draf t) Hendron re: DGB

]

Stamiris 21 10/8/78 Meeting Notes Afifi Filt 10/8/78 Meeting with 4008 Wown: 4030

(Final draft) Hendron re: DGB Stamiris 22 11/17/78 Letter Hendron Afifi Summary of 11/7/78 4039 4057 8/11/81 Champaign meeting Stamiris 23 11/16/78 Meeting Notes Swanberg File Bechtel/CPCo/Hendron 4039 4068 8/11/81 d

(Dechtcl) meeting re instru-mentation and pre-loading

]

Stamiris 24 11/21/78 Memo Peck File DGB settlement concerns 4039 4035 8/11/01 i

10/25/79 10/25/79 Ann Arbor Stamiris 25 Meeting Notes 4039 4094 8/11/81 meeting w/Bechtel, CPCo Hendron, Gould J

Stamiris 26 12/20/78 Memo Peck File 12/14/78 Meeting w/ 4061 Not in

t. Bechtel re: DGB Evider.ce*

settlement j

i

Still open as of end of 9/11/81 l

_ _ __- _ _ - - . ._. _. . _ _ _ ._ _ _ , . . - .m. _ .. _ _ . .

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b l Midland OM/OL Ilearings Exhibits 1

DATE OF IDENTIFIED IN EVIDENCE DATE IN EXHIBIT DOCUttENT DOCUf1ENT FROM TO SUBJECT AT TR. AT TR. EVIDENCE 2

1 Staniris 27 9/29/77 Boring Log I!old No. E at Evap- 4290 4339 8/13/81 orator and Aux.

I Boiler 9uilding i Stamiris 28 1/8/81 Letter ("SALP Keppler Cook 11/24/80, 12/2 and 5352 5352 10/16/81

, Report") 12/17/80 mgmt. meet-ingst I&E 80-36/

j 80-37 re: OA, control -

of Bechtel, timeli-

ness of documentation Stamiris 29 9/1/81 Internal Rutgers Cook f1 CAR 24 - Final Report 5353 5353 10/16/81 j Rechtel (Bechtel- (DGB Settlement)

Report Proi . Mar. )

i Stanirls 30 4/24/79 Graphs: (1) Attachments DEE to 5896 5397** 12/1/81 i Option 1 -- Stamiris's 11/16/81 Preloadina Request.

j of DGB soils; I (2) dates of l DGB surcharge

]

application i

i Stamiris 31 1/8/82 Letter J. G. Bloom Board CPCo 1/7/82 News 7133 7135 2/2/82 l Release re: construc-i tion cost increases

)

I i ** Clarification at Tr. 5977 (12/3/81)

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. Midland OM/OL Hearings Exhibits DATE OF IDENTIFIED IN EVIDENCE DATE IN EXHIBIT DOCUMENT DOCUMENT FROM TO SUBJECT AT TR. AT TR. EVIDENCE Stamiris 32 2/5/82 Memo Hood Summary of 1/26/82 7466 7485 2/17/82 TC re: surcharge

results for DWST

. foundations Stamiris 33 1/15/82 Letter NRC Cook Transmitting 1/8/82 7477 Not in geotechnical con- Evidence sultant's comments

, (HNS) on BWST foundation i

Stamiris 34 10/20/80 Letter Tedesco Cook Report for details of 7809 7822 2/18/82 stress analyses for s underground piping Stamiris 35 10/16/80 Memo Hood Summary of 7/18/79- 7827 7838 2/18/82 meeting on soil deficiencies Stamiris 36 11/22/79 Report nechtel Pipe Corrosion 9390 9392 11/18/82 Stamiris 37 1/26/81 Report nechtel Pipe Corrosion 9390 9392 11/18/82 Stamiris 38 7/27/82 Trip Report Bechtel Pipe Corrosion 9390 9392 11/18/82

. Stamiris 39 4/28/82 Letter D. Miller Davis Confirm Stop Work 11592 11600 2/15/83 i Stamiris 40 5/19/82 FSW-22 nird Stop Mergentime 11647 11649 2/15/83 1

j Stamiris 41 5/19/82 Oral Com Sevo Stop Kelly 11715 11715 2/16/83 i

l

_ .m . _ .

l Midland OM/OL Hearings Exhibits 4

DATE OF IDENTIFIED IN EVIDENCE DATE IN 4 EXHIBIT DOCUMENT DOCUMENT FROM TO SUBJECT AT TR. AT TR. EVIDENCE I Stamiris 42 5/26/82 Letter and Bird Hughes Drilling void 11741 11741 2/16/83 i SCRE 51 i

S2amiris 43 5/19/82 Activity Hold Bechtel Hold on OBS-4 and 11742 11743 2/16/83 OBS-1A Stamiris 44 2/3/83 List CPCo Pipes hit by drilling 11758 11759 2/16/83 Stamiris 45 12/23/80 Le tter Staff Marshall Dewatering Wells 13626 Not in evidence j Stamiris 46 12/10/82 Draft Status Burgess Shafer Monthly Status Report 14492 14492 4/27/83 Report (NRC) through Construction Status

] Stamiris 47 9/2/82 Letter Warnick CPCo Noncompliance item 14547 14547 4/28/83 82-05-02 (a&b) still valid i Stamiris 48 12/15/82 Oral Commun- Wells wells and Shafer dis- 14547 14547 4/28/83 ication cussion of OA/OC organization plan

Stamiris 49 10/29/82 Memo Warnick Novak Reg Guide 1.29 Excep- 14587 14587 4/28/83 l tions Stamiris 50 3/4/83 IR 83-01 NRC Inspection of 1/11- 14645 14646 4/28/83 i 14/R3; Notice of Violation re: no l dacumentation in weld j fabrication problem 1

J

l Midland OM/OL Hearings Exhibits i DATE OF IDENTIFIED IN EVIDENCE DATE IN EXHIBIT DOCUMENT DOCUMENT FROM TO SUBJECT AT TR. AT TR. EVIDENCE 1 Stamiris 51 2/83 Report Corley CPCo Site visit to evaluate 14643 Withdrawn:

crack reported 2/18/83 14749 in roof of feedw.1ter I isolation valve pit f Stamiris 52 2/3/83 Letter S. Poulous Fane Electrical Penetration 14671 14749 4/28/83 l (Geotech- Area; plotting of data i nical Engi-neerina) 2 Stamiris 53 12/9/82 CPCo mano J. Cook Regulatorv Interface - 14709 14749 4/I8/83 CCP 1

l Stamiris 54 2/14/83 NRC Bechtel Drilling into SWP Duct 14724 14749 4/28/83

Rev. Bank 1

3/24/83 i

Stamiris 55 5/4/82 SALP Rpt. NRC Period 7/1/80-6/30/81 14764 14806 4/29/83 Stamiris 56 5/17/82 CPCo Response CPCo NRC SALP response 14781 14806 4/29/83 to SALP i

Stamiris 57 Handwritten Shafer Comments on CPCo SALP 14781 14806 4/29/83 notes resnonse Stamiris 58 Typed copy of R. Cook Comments on CPCo SALP 14808 15983 5/5/83 comments on response SALP response Stamiris 59 Itandstritten (Landsman?] 6/21/83 SALP meetino 14834 14916 4/29/83 notes

I e

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< Midland OM/OL Hearinas Exhibits l

l DATE OF IDENTIFIED IN EVIDENCE DATE IN EXHIBIT DOCUMENT DOCUMENT PROM TO SUBJECT AT TR. AT TR. EVIDENCE i

j I

Stamiris 60 10/1/81 Memo (includes Pirtle Boyd Supplemental SALP 14840 14916 4/29/83

,! 9/22/81 memo) input from DETI.

u

Stamiris. 61 8/6/82 Memo R. Cook Spessard Extend SALP III 14897 14916 4/29/83 1 period i

i Stamiris 62 4/1/83 Memo Keppler DeYounq SALP: Zimmer and 14906 14916 4/29/83 (IE) Midland 4

Stamiris 63 4/18/83 Memo Keppler Hind and SALPr Zimmer and 14910 14916 4/29/83

] Warnick Midland j

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'I a Midland OM/OL Hearings

} Exhibits I

i '

DATE OF IDENTIFIED IN EVIDENCE DATE IN EXHIBIT DOCUMENT DOCUMENT FROM TO SUBJECT AT TR. AT TR. EVIDENCE Stamiris 64 9/22/82 Memo (with Hood Summary of 9/8/82 meet- 14964 Not in

l 9/7/82 draf t ing (Staff & Mooney) on evidence letter) soils related QA improve-ments I Stamiris 65 9/24/82 Memo Warnick Keppler Review of CPCo commit- 14990 15093 4/30/83 ments by Midland Section Stamiris 66 11/24/82 CPCo meeting B. Peck 11/23/82 Meeting with 15092 15092 4/30/83 notes NRC Stamiris 67 7/82 to Activity Log Shafer Chronology of Midland 15092 15092 4/30/83 3/83 Section Activities, 7/82 to 3/83 Stamiris 68 Log (pp. 1-50) Adensam Handwritten notes re: 15720 Not in 5/4/83

, CAP discovery request evidence for BS but will

" travel with the

, record."

See Tr.

l T5732 4 Stamiris 69 9/10/82 Draft Letter CPCo NRC Summarizing review dis- 15739 15741 5/4/83 cussions on soils .

remedial construction l

t 4

}

)

Midland OM/OL Hearings l Exhibits DATE OF IDENTIFIED IN EVIDENCE DATE IN

EXHIBIT DOCUMENT DOCUMENT FROM TO SUBJECT AT TR. AT TR. EVIDENCE Stamiris 70 9/10/82 Draft Letter CPCo NRC Material in addition to that 15739 15741 5/4/83

, in Stamiris Exh. 69, re:

Total OA implementation Stamiris 71 Undated Draf t Letter NRC CPCo Responding to two Sept. 17 15741 15742 5/4/83 (Keppler) lettets from JWC (drafts of which are Stam. Exh.

69-70) '

Stamiris 72 Notes NRR Comments on Proposed letter 15741 16333 5/6/83 (Comments) from Keppler (Stam. Exh. 71).

, Stamiris 73 Testimony Last page of draf t of JGK's 15753 15755 5/4/83 Draft 10/29/82 testimony t

! Stamiris 74 12/21/82 Memo Hernan Novak 12/7/82 meeting on Midland 15756 15756 5/4/83

(NRC) OA Implementation I

Stamiris 75 9/7/82 Memo (w/o Hood Summary of 8/17/62 meeting 15756 15756 5/4/83 j enclosures) on soils-related construction release.

Stamiris 76 7/21/82 QAR F-189 IPINs indentifying deficien- 15757 15757 5/4/83 1 cies reinstallation of under-j pinning instrumentation; con-2 cern about repetitiveness of

, deficiencies.

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Midland OM/OL Hearings Exhibits 1

4

DATE OF IDENTIFIED IN EVIDENCE DATE IN EXHIBIT DOCUMENT DOCUMENT FROM TO SUBJECT AT TR. AT TR. EVIDENCE i

Stamiris 77 G. Klinger Midland Enforcement Package: 15757 15758 5/4/83

! (IE) general comments l l Stamiris 78 8/18/82 QAR F-197 Quality indicator Graph for 15950 Not in l

! period 6/16-7/15/82 indica- evidence

! til.'q potential adverse trend. l l Stamiris 79 Handwritten No.es from 12/7/82 meeting 16006 Not in notes evidence d Stamiris 80 Notes / Slide Goals of QC integration into 16608 Not in presentation MPOAD (from Brugess' files - evidence perhaps generated by Wells)

J l Stamiris 81 12/3/82 Letter Cook Denton Qualification of inspection, 16620 16694 6/2/83 1 examination, and testing -

i audit personnel at Midland, r i

Stamiris 82 2/24/83 Oral Commun- Ewert Performance demonstrations 16641 16655 6/2/83 unication for inspector qualifications

Pecord -- schedule changes.

- Stamiris 83 8/19/82 Letter w/POCI Bechtel Turnbull Soil Stabilization 16645 Not in 7220 cvidence 4

5 t'

l

)

4

1 1

Midland OM/OL !! earings Exhibits i

4

{ DATE OF IDENTIFIED IN EVIDENCE DATE IN EXHIBIT DOCUMENT DOCUMENT FROM TO SUBJECT AT TR. AT TR. EVIDENCE 4

Sta,miris 84 10/25/82 MPQAD Davia- MPQAD Procedures re QC certifica- 16648 16659 6/2/83 tion Request tion No. 21 Stamiris 85 No Date CPCo Handout Indep. 3rd Party Reviews -- 16659 16679 6/2/83 Indep. Design Verification --

r otstruction Implementation

. n r'riew -- Soils Remedial

! activities. (Gardner's copy, with his notes).

Stamiris 86 No Date CPCo handout CCP Quality Activities, 16665 16679 6/2/83 to Caseload Reinspection Scope &

forecast panel Assumptions q Stamiris 87 12/82- Phone Log B. David 16716 Not in 12/83 Reg. III evidence Stamiris 88 10/2/81 Policy otmt. Selby, CPCo & Midland Quality Policy 16728 16730 6/2/83 Wahl Bechtel Presentation by Selby &

Employees Wahl Stamiris 89 5/24/83 Board Notif- Novak ASLD llold Tag Violation during 17040 17050 6/4/83 ication remedial underpinning con-struction Stamiris 90 3/12/82 letter flood Simmary of 3/10/82 meeting on 17187 17188 6/6/83 '

OA in remedial foundation work 4.

1 I

l 1

Midland OM/OL Hearings Exhibits DATE OF IDENTIFIED IN EVIDENCE DATE IN EXHIBIT DOCUMENT DOCUMENT FROM TO SUBJECT AT TR. AT TR. EVIDENCE i

Sttmiris 91 10/4/82 Transmittal Bechtel CPCo Note: Portion same as 17188 17189 6/6/83 QAR F-197 (w/ Stamiris 78 Trend Graph)

Stsmiris 92 2/12/82- IPIN log Shows IPINs upgraded to NCRs 17202 17202 6/7/83

10/4/82 (Spring-Summer 1982, 19pp.)

I Stamiris 93 11/22/82 Letter Hood Sammary of 11/5/82 meeting on 17225 17293 6/7/83

, Independent Assessment of Underpinning at Aux. B]dg.

j Stamiris 94 IR for IR and NOV 17642 Not in q Nine Mile evidence ,

1 Point ,

t i Stamiris 95 1/18/83 3 drafts and Reg. III CPCo Weil investigation into 17528 17529 6/8/83 final cover whether CPCo made misleading letter statementu to NRC inspectors i on 3/10 & 3/12.

. Stamiris 96 5/82- Handwritten Weil Information from interviews 17921 17921 6/10/83 6/82 notes with R. Black Stamiris 97 11/19/82 Report to Novak Shewman 18157 18452 6/28/83 ACRS Stamiris 98 1/12/83 Dechtel Engineering mark-up of CCP 18306 Withdrawn:

18455

Midland OM/OL Hearings Exhibits DATE OF IDENTIFIED IN EVIDENCE DATE IN EXHIBIT DOCUMENT DOCUMENT ' ROM TO SUBJECT AT TR. AT TR. T/IDENCE Stamiris 99 Handwritten B. Tre D. Miller 18323 18457 6/28/83 notes Stamiris 100 7/29/82 Memo Keeley Bechtel Design Review. Note 18356 18512 6/29/83 55 thru 4.4, plus conclusion (Portions) is i, evidence Stamiris 100A 5/28/82 Memo BPCo Keeley Midland IDV (proposed) 18604 6/29/83 Stamiris 101 5/27/83 Report TERA AFW System 18359 18461 6/28/83 (cover date)

Stamiris 102 9/20- Audit Report Hydrostatic testing 18402 18461 6/28/83 9/29/82 Stamiris 103 OAR F-120 18866 Stamiris 104 11/16/82 NCR NCR IM01-5-22-166 18966 18967 7/1/83 Stamiris 105 BPCo Procurement doc.; Certificate 18991 of Conformance 6

-- w - , , ,

Midland OM/OL Hearings Exhibits DATE OF IDENTIFIED IN EVIDENCE DATE IN EXHIBIT DOCUMENT DOCUMENT FROM TO SUBJECT AT TR . AT TR. EVIDENCE Sinclair 1 11/16/81 Report: Draft Singh NPC DGB & SWPS 10621 10625 12/8/82 Sinclair 2 4/5/83 Letter Keppler GAP Stone & Webster, CCP 15529 15529 5/3/83 Sinclair 3 2/18/83 Memo Shafer Warnick Stone & liebster 16116 16363 5/6/83 Portions that are admitted:

See Tr. 15705-W Sinciair 4 Page 6-1 of CPCo 8 33, 16956 Not in evi-S & W 90-day Report dence: See Tr. 18596 !98.

Sinclair 5 1/19/83 Summary flood 18488 18599 6/29/83 Sinclair 6 Handwritten Wells 11/27/82 meeting: 18567 Not in evi-notes 4 pp. donce as of 7/1/83

Appendix B J A Meeney

Emeanier Maanger "d!=2 hojees Offier Gomosel Offtmas 1ses west Perrell Fleet. Junkenst, tal 4e301

ts17) 7sN1774 ,

r July 28, 1983 ,

~

Mr J J Harrison Midland Project Section U S Nuclear Regulatory Commission Region III 799 Roosevelt Road Glen Ellyn, IL 60137 MIDLAND ENERGY CENTER GWO 7020 REMEDIAL SOILS WORK AUTHORIZATION -

File: 0485.16 UTI: 42*05*22*04 Serial: CSC-6798 12*32 We are enclosing the proposed list of work accordance with the "NRC cud CPCo Work Authorization Procedure" for the period between August 1,1983, and August 31, 1983. Please review this work list and authorize the specific work items as established in the procedure.

Also. enclosed is a Supplemental Work Activity List for September, 1983. Your review, comments and authorization of the specific work items as in accordance with the procedure are similarly requested.

c0 i

i JAM /AEB/klm .

Attachment O

OC0783-0005B-CN01 .

1 wa .. rs Pcwar Comp =y Attcchment to Serial CSC-6798 ,

kdl.oii Plant Units 1 & 2 -

WORK ACTIVITY LIST FOR THE PERIOD BETWEEN AUGUST 1, 1983 and AUGUST 31, 1983 :

6 DEVEthPED IN COMPLIANCE WITN ASLB ORDER OF APRIL 30, 1982 UC'.! Olt ACTIVITY PREVIOUS REGION III

[VI::Fl> ITEMS IDENTIFIER PROGRAM, WORK AREA & ACTIVITY DESIGNATION GENERAL QUALITY PROGRAM 102351100 Approval of HPQP-2, Rev 1 -

A(10/22/82) 102351120 Approval of MPQP-1, Rev 6 , , , A(6/20/83) r AUXILIARY BUILDING'& FIVP UNDERPINNING PROGRAM WEST FIVP 102150010 Install Anchor Bolts & Rods 1 (8/12/82) A (8/13/82)

(includes hardness test on rods, drill concrete & steel and tensioning)

EAST FIVP

~

112150010' Install Anchor Bolts & Rods 1 (8/12/82) A (8/1'3/82)

(includes hardness tests on rods, drill concrete & steel, and tension) . ,

l 162550010 WEST TURBINE / AUX BUILDING PIPE TUNNEL HODIFICATION

! Install Platform at El 600' 1 (4/5/83) A (4/20/83) i (includes installation of Pipe Tunnel Reinforcement, j cutting of opening, Hodification of Handrails and Ladder and Protection of Existing Piping) ,

162550100 Exploratory. probe for UAT (West) 162550012 Pregrout from IJAT. (West) e o em e [

2 n:. n Powar Comp::y ,

Attachment to Snrial CSC-6798

$na... Plant Units 1 & 2' e

WORK ACTIVITY LIST FOR TNE PE'RIOD BETWEEN AUGUST 1, 1983 and AUGUST 31, 1983 i DEVELOPED IN COMPLIANCE WITH ASLB ORDER OF APRIL 30, 1982

~

.:J

, OR ACTIVITY PREVIOUS REGION III p;il:p, ITEMS IDENTIFIER PROGRAN, WORK AREA & ACTIVITY DESIGNATION 152550010 EAST TURBINE / AUX BUILDING PIPE TUNNEL HODIFICATION Install Platform at El 600' . 1 (4/5/83) A (4/20/83)

(includes installation of Pipe Tunnel Reinforcement, cutting of opening, Hodification of Handrails and Ladder and Protection of Existing Piping) 152550100 Exploratory probing for UAT (Eas,t) ,,

152550012 Pregrout from UAT (East)

BUILDING MONITORING 136050043 Maintain Instrument System 3 (8/12/82) A (8/12/82) 132550027 Install strain gauges and terminate cables A(07/28/83)

(includes testing and calibration) 132550050 Install, wire conduit and raceway from pier 2(12/13/82) A(12/13/82) to data room for Pier Instrumentation , ,

165052021 Terminate Cables in Data Roon & Terminal Boxes A (3/10/83)

& Pier Instrumentation GENERAL TEMPORARY DEWATERING 125150050 Continue Monitoring Utility Protection Pits (4) 3 (8/12/82) A (8/12/82) 115150020 Continue Operation of Freeze System & Wells 3 (8/12/82) A (8/12/82) 522550025 Excavate, Repair and h ckfill Piezometer HP-2 1 (4/5/83) -

522550020 Repair Six (6) Existing Observation Wells (WB-1, WP-2, COE-10 PD-18, W-2, PD-38) 1 (4/5/83)

~

125150051 Install Clay to Below Duct Bank (pit 4) 1 (8/12/82) io:: a-2439d173-12 JEKostielney 01/20/E3

3

j. . .s Powar Coopery ,_

Attachme=t to Sarial CSC-6798 '

ill..... Plant Unita 1 & 2 WORK ACTIVITY LIST FOR THE PERIOD BETWEEN AUGUST 1, 1983 and AUGUST 31, 1983 i

DEVELOPED IN COMPLIANCE WITH ASLB ORDER OF APRIL 30, 1982 -

I

. OR ACTIVITY PREVIOUS REGION III L.'j : Tis,,,lTEMS IDENTIFIER PROGRAN, WORK AREA & ACTIVITY DESIGNATION 125150052 Repair Ductbank (Pit 4) 1 (8/25/82)

(includes excavate, drift, repair and backfill) 115150026 Remove 36" Casing and Backfill 42" Hole 1 (9/17/82) 115150025 Clean out and backfill abandoned,ej,ector holes (NE26A, HE28A and HE54) -

R 102550135 Install piezometers BB1 & BB2 in Auxiliary Building A(07/28/83)

Control Tower CRACK NAPPING (includes scaffoldin8 platforms, ladders and extra-ordinary clean up) 102250200 EPA (East & West) 3 (8/12/82) A (8/12/82)

~

102250105 FIVP (East & West) 3 (8/12/82) A (8/12/82) 102250100 Control Tower & Remainder of Aux Bldg . 3 (8/12/82) A (8/12/82)

PIER 12W 165054010 Install & Load Pier 12Wa 1 (8/12/82) A (12/9/82)

PIER 11W 165054015 Install & Load Pier 11Ws 1 (8/25/82) A (2/22/83)'

(includes install bituminous plywood forms)

PIER 9W 165054005 Install & Load Pier 9W8 1 (9/17/82) A (2/24/83)

PIER 12E

.0!:ra-2439dl,73-12 JEKostielney 07/20/83

~

u

.:. Power Comp y Attacharat to Serial CSC-6798 (1e-ii i . . viant Unita 1 & 2 ,

WORK ACTIVITY LIST FOR THE PERIOD BETWEEN AUGUST 1, 1983 and AUGUST 31, 1983 DEVELOPED IN COMPLIANCE WITH ASLB ORDER OF APRIL 30, 1982

.. 01: ACTIVITY

PREVIOUS REGION III WIF.i (TEMS IDENTIFIER PROGRAM, WORK AREA & ACTIVITY DESIGNATION 155054010 Install & Load Pier 12E8 1 (8/12/82) A (12/9/82)

PIER 11E 155054015 Install & Load Pier 11Es 1 (8/25/82) A (2/22/83)

PIER 9E 155054005 Install & Load Pier 9E8 1 (9/17/82) A (2/24/83)

PIER SE 155054020 Install & Load Pier sea 1 (9/17/82) A (5/3/83)

GRILLAGE STRUCTURE AT PIER 8E 155053025 Excavate for Support Columns next to containment 2 1 (9/17/82) A (6/20/83) 155055003 Install Steel Support Columns next to Containment 1 (9/17/82) A (6/20/83) 155055010 Install & Load Grilla8e Structure at Pier 8E 1 (9/17/82) A (6/20/83)

PIER 8W -

165054020 Install & Load Pier 8W8 1 (9/17/82) A (5/3/83)

GRILLAGE STRUCTURE AT PIER 8W Excavate for Support Columns next to containment 2 165053025 1 (9/17/82) A (6/20/83) 165055003 Install Steel Support Columns next to Containment 1 (9/17/82) A (6/20/83) 165055010 Install & Load Grillage Structure at Pier 8W 1 (9/17/82) A (6/20/83) 10.i... -2439d173-12

- JEXostielney 07/20/83

L .

< x 5 1

j. . fower Compn:::y .

Attochae:t to Strict CSC-6793 11 I'lant Units 1 & 2

[ WORK ACTIVITY LIST FOR THE' PERIOD BE1VEEN AUGUST 1, 1983 and AUGUST 31, 1983 j, 8 DEVELOPED IN COMPLIANCE VITR ASLB ORDER OF APRIL 30, 1982

J. Oil 1 - ACTIVITY . .

PREVIOUS REGION III N : 0,,,1TEMS . IDENTIFIER FROGRAM, WORK AREA & ACTIVITY DESIGNATION EXCAVATION ZONES, +

15505202.9 Excavate / Lag Zone 71- 1 (4/5/83) A (6/20/83)

.s , . h. ~ .

g ,

'165052020 c Excaste/ Lag Zone 21 ~ ,

1 (4/5/83) A (6/20/83) 1

_ 5/

165'050375 Excavate / Lag Zone 22 , , A (5/27/83) '

'l N', . 155056375 Necavate/LagZoneY2 s A (5/27/83)

, j 1 l.-; '

PIER W10

^

j 165054030 Install & Load Pier 10W8 1 (4/5/83) A (5/3/83)

.s PIER E10 5 155054030 Install & Load Pier ~10Ea 1 (4/5/83) A (5/3/83)

SLAB Modificati40 at El 659'.0A 102250206 Survey / Layout for Engineering Review in Preparation for 1

Slab'Fix @ El 659 . 3 (4/5/83) A (4/5/83)

PIER KC2

,'s 165054315 Install & Load Pier KC28 -

1 (9/17/82) A (4/22/83)

PIER KC11 155054315 Install & Load Pier KC118 1 (9/17/82) A (4/22/83)

PIER XC3 165052310 Drift'to KC3 from W81 ,

A (07/28/83) 165053310 Excavate Pier KC32 A (07/28/83)

, 165054305 Install & Load KC38 . A (07/28/83)

On::2-2439d173-12 JEKostielney 07/20/W1

6 on.: ... Pewsr Compry

Attechnent to Sarial CSC-6798

ielf . Pl. int Units I & 2 ~

WORK ACTIVITY LIST FOR THE PERIOD BETWEEN AUGUST 1, 1983 and AUGUST 31, 1983 DEVELOPEDINCOMPLIANCEW[THASLBORDEROFAPRIL 30, 1982 i: : Ult ACTIVITY PREVIOUS REGION III EV y ..'i. J TEMS IDENTIFIER PROGRAM, WORK AREA & ACTIVITY DESIGNATION 4 PIER KC10 155052310 Drift to EC10 from E81 A (07/28/83) 155053310 Excavate Pier KC102 A (07/28/83b 155054305 Install & Load EC108 .

, A (07/28/83) l j PIER W14 4

165052057 Drift From West Access Shaft to Pier U141

, (includes Access Pit) A (5/27/ti)) ,

165053055 Excavate Pier W142 A (5/27/n:s) 165054050 Install Pier W14 A (5/27/113)

PIER E14 155052057 Drift from East Access Shaft to Pier E141 A (5/27/83)

(includes Access Pit) 155053055 Excavate Pier E142 A (5/27/83) 155054050 Install Pier E14 A (5/27/83) io..'t-1439d173-12 JEKostielney 07/20/lis!

7

c. l'owar Comp;ny Attachment to Serial CSC-6798 ,

{m: .li... L' tant Units 1 & 2 .

WORK ACTIVITY LIST FOR THE PERIOD BETWEEN AUGUST 1, 1983 and AUGUST 31, 1983 i DEVELOPED IN COMPLIANCE WITN ASLB ORDER OF APRIL 30, 1982 I

3 T OR ACTIVITY PREVIOUS REGION III (Vlff; ITEMS IDENTIFIER PROGRAM, WORK AREA & ACTIVITY DESIGNATION SERVICE WATER PUMP STRUCTURE UNDERPINNING PROGRAN POST TENSIONING SYSTEM 202555170 Post Tensioning Tendon inspection & maintenance 3(12/7/82) A (12/7/82)

DEWATERING 207050605 Install Remaining Ejector Wells , ,, A (6/23/83) 207050385 Core Drill SWPS Slab for Ejector Wellu A (3/17/81) 207050386 Core Drill CWIS Slab for Ejector Well:. 1(11/1/82) A (3/17/i.1)

, 207050748 Probe for Deep Utilities Outside El 610 Excavation Limits -

l (Ref Dwg C-2031) 1 (4/5/83) A (5/27/In) i 20705038d Core drill SWPS and CWIS slabs for Piezometers A (4/13/113) i l 207050600 Install Piezometers A (6/23/83) 207050635 Install Dewatering Discharge System 2 (9/17/82) A (6/23/83)

(including headers, tank, pumps and electrical) .

l 207050387 Convert 7 Wells used on 72" pipe repair to support SWPS 1(11/1/82) A (2/11/83) j dewatering. (Includes install new ejectors, temporary

headers, operate, & maintain)

)

! Fill SWPS Chambers (Bays) ~

], 203150165 Fill SWPS Chambers with Water to El 622 (15')

t Hodify Pipe Supports

! 202550164 SWPS - Modify pipe supports to allow for design load A (5/27/83)

. (30" ONBC 34, 20 & 16) ,

i i tr D.2 -2439dl 73-12 JEKostielney 07/20/83

. g m.- . Powar Comps:y Attechnent to Serial CSC-6798 il l . Plant Units 1 & 2 W ACTIVITY LIST FOR Tite PE'RIOD BE1 WEEN AUGUST 1, 1983 and AUGUST 31, 1983 i i

DEVELOPED JH COMPLIANCE WITH ASLB ORDER OF APRIL 30, 1982

. t .' OR ACTIVITY PREVIOUS REGION III

[yl . :.'t. ITEMS IDENTIFIER PROGRAM, WORK AREA & ACTIVITY DESIGNATION

ACCESS SHAFT & EXCAVATION 207050335 Install Soldier Piles 1 (8/12/82) A (5/27/83)

BUILDING MONITORING 202550100 Install Deep Seated Beach Marks 1 (8/12/82) A (4/4/83) 206050105 Crack Nap SWPS , ,,

I (9/17/82) A (3/10/83) 202550130 Inst 411ation of Extensometer Anchors 1 (4/5/83) A (4/13/83) 202550120 Installation of Extensometer Covers 3 (4/5/83) A (4/5/83) 206050100 Install Extensoneters 1 (9/17/82) A (5/27/83) :

l 206050106 Install Instruments and Terminate Instrument Cables 1 (9/17/82) A (5/27/H3) !

(Includes testing & calibration) 206050102 Install Brackets 1 (9/17/82) A (4/20/83) 207550103 Install Conduit & Raceway 1 (9/17/82) A (2/22/83) 202550104 Install cable and terminate at Data Acquisition Room 1 (9/17/82) A (5/27/83) 206050101 Install Permanent Benchmark Covers 1 (9/17/82) A (4/20/83) 206050104 Baseline, Operate, and Haintain Instrument System R

~

DUCTBANK PENETRATION 852450105 SWPS - Provide Ducktbank Penetration in SWPS Wall and install pull box.

JEKostielney 07/20/83 a un . .'.- 24 39 .d 173- 12 g

9 po cs Power C:mpary I Attechment to Snrini CSC-6798 io. Plant Units 1 & 2 '

(~ .i .

WORK ACTIVITY LIST FOR'THE PERIOD BETWEEN AUGUST 1, 1983 and AUGUST 31, 1983 i

DEVEI4PEDINCOMPLIANCE}ITHASLBORDEROFAPRIL 30, 1982

.... OR ACTIVITY PREVIOUS REGION 111 fi' . q ITEMS IDENTIFIER PROGRAM, WORK AREA & ACTIVITY DESIGNATION BORATED WATER STORAGE TANK FOUNDATION & TANK REPAIR PROGRAM UNIT 1 TANK 312150005 Drill and Grout Shear Connectors 2(12/13/82) A (4/20/83) 312150007 Prepare concrete surfaces, drill holes & remove A (4/20/83) concrete for rebar. . . .

312150011 Construct New Ring Beam 1 (8/12/82) A (7/8/83)

(set forms.& place rebar, pour concrete) 312550019 Reinstall Electrical Ductbank 2 (9/17/82) A (4/6/83) 312550018 Reinstall Piping, Pipe Hangers and Electrical Facilities A (3/17/83)

UNIT 2 TANK 322150005 Drill and Grout Shear Connectors 2(12/13/82) A (4/20/83) 322150007 Prepare concrete surfaces, drill holes & remove concrete A (4/20/83) for rebar 322150011 Construct New Ring Bean 1 (8/12/82) A (7/8/83)

(set forms & place rebar, pour concrete) 322550019 Reinstall Electrical Duct Bank 2 (9/17/82) A (4/6/83) 322550018 Reinstall Piping, Pipe Hangers and Electrical Facilities A (3/17/831 322150212 Repair Tank Weld Defect R e

io.;Uj.'439d173-12 JEKostielney 07/20/WI

10 a s. . . . Power Company Attechment to Serial CSC-6798 ht .. i>1 ant Units 1.& 2' (

g WORK ACTIVITY LIST FOR THE PERIOD BETWEEN AUGUST 1, 1983 and AUGUST 31, 1983 DEVELOPEDINCOMPLIANCEW[THASLBORDEROFAPRIL 30, 1982

. OH ACTIVITY PREVIOUS REGION III PROGRAM, WORK AREA & ACTIVITY DESIGNATION k11. . . . ITEMS IDENTIFIER UNDERGROUND PIPE REPLACEMENT, REBEDDING, AND HONITORING PROGRAH SHALLOW PROBING FOR PHASE II 407050400 Shallow probing for Phase II (Ref DWG C-2031) A (5/27/83) 4 TRAIN A 0F SERVICE WATER PIPE RFELACEllENT .

402550500 Excavate Existing Pipe 1 (8/12/82) A (5 /27/ri) 402550510 Remove Existing Pipe 1 (8/25/82) A (5/27/H:1) 402550520 Install new pipe & expansion coupling 1 (8/25/82) A (5/27/8*1) 402550515 Hydro Test new pipe A (5/27/83) 402550507 Perform Profiling & Ovality Check on New Piping A (5/27/83) 402550525 Temporary Backfill New Pipe 1 (4/5/83)

CONSTRUCTION WORK IN SOIL MATERIAL PROGRAHS PERMANENT INTRUSION DETECTION SYSTEH 732050002 Install Wire (inc1 conduit) 3 (8/25/82) A (8/25/82) 732050003 Install Fence .

(inc1 fence posts & :oncrete strip) 3 (8/25/82) A (8/25/82) 732050004 Install Grounding 3 (9/17/82) A (9/17/82)

JEKosticluey 07/20/83 f 0"I" 243M173-12

11

.. . s Power Comp =y !

Attr, chm nt to Serial CSC-6798

.l. 1lant Units l'& J' ~i i

' WORE ACTIVITY LIST FOR THE PERIOD BETWEEN AUGUST 1, 1983 and AUGUST 31, 1983

. DEVELOPED IN COMPLIANCE WITH ASLB ORDER OF APRIL 30, 1982 i . i l I ou ACTIVITY PREVIOUS REGION III j'li. ITEMS IDENTIFIER PROGRAN, WORK AREA & ACTIVITY DESIGNATION I OBS-4 Repair 522550018 Dutch Cone Soil Testing in Vicinity A (07/28/83) of OBS-4 for exploratory purposes j Acid-Caustic Unloadina Station Excavate, install and backfill d'raiuline and 822550001 -

1 (11/1/82) A (4/20/83) slab for Acid-caustic unloading station at East end of Turbine Building J

EMERGENCY PERSONNEL LOCKS - UNIT 2 j 792550005 . Excavate, rebar, pour concrete and backfill Airlock Structure 1 (9/17/82)

SIT /ILRT TEST FACILITIES 862450105 Exploratory Excavation at SIT /ILRT Duct Bank , A(5/27/83) i j PERMANENT DEWATERING PROGRAM 522150005- Instal 1' Remaining Wells 1 (9/17/82) 522550016 Install electrical equipment & conduit 1 (9/17/82) f ':

522550020 Excavate, install and backfill header piping, electrical 1 (9/17/82)

, conduit, and pumps (including equipment slabs and '

metering pits) ,

] 522550025 Assemble and wire pump control panels I

6 0: .. '. .8439d173-12 JEKostielney 07/20/83

12 on Powar C mpany , * , Attachment to Seriel CSC-6798 i.l . 1lant Units I & 2

WORK ACTIVITY. LIST FOR THE PERIOD BETWEEN AUGUST 1, 1983 and AUGUST 31, 1983 DEVELOPED IN COMPLIANCE WITH ASLB ORDER OF APRIL 30, 1982

, 1 Olt ACTIVITY PREVIOUS REGION III EV.:'. ITEHS IDENTIFIER PROGRAM. WORK AREA & ACTIVITY DESIGNATION DIESEL FUEL SUPPLY LINES 722050001 Install misgle shielding 1 (8/25/82) 722050002 Excavate, remove, reinstall and backfill 1 (11/1/82)

DF0 supply lines 802450005 Exporatory excavation for examin$ation of diesel A (4/13/83) fuel oil lines DIKE MAINTENANCE 812550010 Normal dike maintenance in Q areas A (5/27/83)

CONTROL ROOM PRESSURIZATION TANK SE'lTI.EtlENT HARKERS 932450100 Excavate for, install and backfill Control Room pressurization tank settlement markers MISCELLANEOUS 942450200 Remove (excavation) temporary uncontrolled fill located 1 (7/5/83) in Q areas (DWG C-45Q) as identified on NCRs and the OGSE action item logs, and backfill per Spec C-211Q 942450300 ' Excavate and backfill trench for around cable east 3 (7/15/83) A (7/15/83) of Tech Support Center.

CATHODIC PROTECTION 752050001 Drill and replace annodes (as necessary) 1 (8/25/82) 752050002 Drill and install new annodes 1 (11/1/82)

0.: *;-: 439d173-12 JEKostielney 07/20/83 i

1 en . Pow 2r Comp:ny

Attachment to Serial CSC-6798 i .l . i'lant Units 1 & 2 '

SUPPLEMENTAL WORK ACTIVITY LIST TOR THE PERIOD BETWEEN SEPTEMBER 1, 1983 AND SEPTEMBER 30, 1983 5

DEVELOPED IN COMPLIANCE WITH ASLB ORDER OF APRIL 30, 1982 I

i 'L. Ol! ACTIVITY PREVIOUS REGION III

$V U _ ITEMS IDENTIFIER PROGRAM, WORK AREA & ACTIVITY DESIGNATION AUXILIARY BUILDING & FIVP UNDERPINNING PROGRAM i SUPPORT BRACKET 4

152555010 Install Temporary Support Bracket at El 162555010 Install Temporary Support Brackep af W1 I

PIER E13 l 155053040 Excavate Pier E132 A (5/27/H3) 155054035 Install Pier E13 A (5/27/h3)

} PIER W13 l

165053040 Excavate Pier W132 A (5/27/83) lI l 165054035 Install Pier W13 A (5/27/83) l 1 DOWELS AT FIVP .

l

, 155050325 Install dowels at east FIVP j 165050325 Install dowels at west FIVP t

! MHL C WAMS .

165055305 ' Install Level C Wales, West Side A (5/27/83) l 155055305 Install Level C Wales, East Side A (5/27/83) iii : 9'-2439fl?3-12

, JEKostielney 07/20/81 i

== ,

eso.. . Pow 2r Comp *.e.y i.o Attachment to Serial CSC-6798 i>1 ant Units I &'{- +

SUPPLEMENTAL WORK ACTIVITY LIST FOR TH1 PERIOD BETWEEN SEPTEMBER 1, 1983 AND SEPTEMBER 30, 1983 DEVELOPED IN COMPLIANCE WITH ASLB ORDER OF APRIL 30, 1982 h

I

...: O!! ACTIVITY p'.1: !: 1TEHS IDENTIFIER PROGRAM, WORK AREA & ACTIVITY

~

PREVIOUS REGION III DESIGNATION PIER CT12 155052035 Drift to CT12 from llATI 155053050 Excavate Pier CT122 155054045 Install & Load' Pier CT12s , ,,

PIER CT1 165Q52035 Drift to CT1 from UATI

- 165053050 Excavate Pier CT12 * '

165054045 Install & Load Pier CT18 PIER KC4 155052032 Finger Drift to XC43 155053315 Excavate Pier KC42 155054310 Install & Load Pier XC43 PIER IC9 165052032 Finger Drift to XC91 165053315 Excavate Pier KC9a 165054310 .

Install & Load Pier KC9a LONG DRIFTS ur '439 f173-12 JEKostielney 07/20

3 i - . Powsr Corpm:y 9 j Attachment to Serial CSC-6798 ali . Plant Units I & 2 r,

, fl.

SUPPLEMEFTAL WORK ACTIVITY LIST FOR THE PERIOD BETWEEN SEPTEMBER 1, 1983 AND SEPTEMBER 30, 1983 DEVELOPED IN COMPLIANCE WITN ASLB ORDER OF APRIL 30, 1982 l

.! . Oil ACTIVITY PREVIOUS REGION III Y l . .@, ITEMS IDENTIFIER PROGRAM, WORK AREA & ACTIVITY DESIGNATION 155052320 Drift to EC4 from KC31 165052320 Drift to KC9 from KC101 A (07/28/83) 155052030 Drift to KC3 from KC21 A (07/28/83) 165052030 Drift to KC10 from KC111 155054515 Construct concrete invert and la'yb'a'ck soil KC2 to KC3 -

1 (7/5/83)

'l*

165054515 Construct concrete invert and layback soil KC11 to KC10 1 (7/5/83)

UNDERGROUND PIPE REPLACEMENT, REBEDDING, AND HONITORING PROGRAM TRAIN B 0F. SERVICE WATER PIPE REPLACEllENT4 402550446.. Excavate Existing Pipe 1 (8/12/82) 402550550' Remove Existing Pipe ,

R 402550560 Install new pipe & expansion coupling R 402550561 Hydro Test new pipe R 402550508 Perform Profiling & Ovality Check on New Piping R 402550562 Temporary Backfill New Pipe 1 (4/5/83)

)

e e

)or ..:-2439f173-12 JEKostielney 07/20/83

4 Attache:ct to Serial CSC-6798 m . Power Company,.i , ,, '

.o. Plant Units.1.E 2.

j< *

n : .

SUPPLEMENTAL WORK ACTIVITY LIST FOR TNE PERIOD BETWEEN SEPTEMBER 1, 1983 AND SEPTEMBER 30, 1983 DEVELOPEDINCOMPLIANCEW[THASLBORDEROFAPRIL 30, 1982

. i ' ' Ol! ACTIVITY ' PREVIOUS REGION III gl . :J lTEMS IDENTIFIER PROGRAM, WORK AREA & ACTIVITY DESIGNATION

'~' SERVICE WATER PUMP STRUCTURE UNDERPINNING PROGRAM EXCAVATION I

207050781 Excavate, lag, brace and install wales and struts in upper east section of SWPS access shaft (soldier piles 14 thru 30 - maximum excavation to EL 618'-3" -

excluding localized excavation a't pipe supports).s 207050782 Excavate, lag, brace and install wales and struts in upper west section of SWPS access shaft (soldier Piles 1 thru 14 - maximum excavation to EL 624'-9"

excluding localized excavation at pipe supports.)6 207050783 Excavate lag, brace and install wales and struts, pour 1 (7/5/83) and cure concrete mudsat in lower east section of SWPS access shaft (soldier piles 15 thru 30 - maximum excavation to EL 618'16" excluding localized . .

excavation.)8 207050784 Excavate, leg, brace and install vales and struts, I (7/5/83) pour and cure concrete mudmat in lower west section l' of SWPS access shaft (soldier piles 1 thru 14 -

saximum excavation to EL 618'16" excluding localized c.acavation.)s 1 (11/1/82) A (5/27/83).

202550163 Remove abandoned fire protection pipeline DEWATERING SYSTEM l 207050620 -

. Activate, Operate and Maintain Dewatering System 1 (9/17/82) A (5/27/83)

BORATED WATER STORAGE TANK FOUNDATION AND TANK REPAIR PROGRAM ,

,io ' 4 - ::1. M 173-12 JEKostielacy 07/20/10

~

5

. i

>s . . c:: Power Comp:ny'.. . Attacharat to Sarial CSC-6798 a- i'lant Unita 1 & '2' '

f

- i. l

' i),. .

f : ,

SUPPLEtGtNTAL WORK ACTIVITY LIST FOR THE PERIOD BE'lWEEN SEPTEMBER 1, 1983 AND SEPTEMBER 30, 1983

. , DEVELOPED.IN COMPLIANCE WITH ASLB ORDER OF APRIL 30, 1982

'l l OR ACTIVITY ! . PREVIOUS REGION III TI.<::i 1TEMS IDENTIFIER PROGRAM, WORK AREA & ACTIVITY DESIGNATION 312150015 Relevel Tank-Unit 1' .

1 (9/17/82) 312550100 ,

Install Instruments (inclu' des testing and calibration) 1 (11/1/82) 322550100 Install Instruments (includes testing and calibration) 1 (11/1/82)

CONSTRUCTION WORK IN SOIL HATERIAL ERbtilAHS -

PERMANENT DEWATERING 522550014 Excavate Headers & Metering Pits, Install Header and Level Monitoring System, Install himps, -

-Timers and Backfill

.., CONTAINHENT TENDON ACCESS VENT HVAC 802550010 Excavate for, Install and Backfill Electrical Duct '

1 (9/17/82)

Bank and Equipment Pad for the Unit 1 HVAC Fan 802550020 Excavate for, Install and Backfill Electrical Duct . 1 (9/17/82)

Bank and Equipment Pad for the Unit 2 HVAC Fan NITROGEN TANE INSTALLATION 782550005 Excavate for, install and backfill electrical duct bank 1 (9/17/82) 782550010 Excavate for, install and backfill piping 1 (9/17/82) 1 (9/17/82) 782550015 Excavate for, install and backfill concrete pad 1 (9/17/82) 782550020 Excavate for, install and backfill nitrogen tanks and associated concrete structures 5u. .-2439f173-12 JEKostielney 07/20/t11

' ir References to SER/ Supplements in Hearing Transcripts DATE WITNESS TR. (S)SER Section HEARING MATTER 11/15/82 Hood 08703-08713 SSER #2, Seismic Shakedown Table 2.4 (corrections of SSER #2)

S3.12.2 Figure 2.8 S2.5.4.6.1.1.

S3.8.3.2 Figure 3.1 S3.8.3.5.

59.2.1.

1.3 Appendix I Sl.7

p. 2-50 Hendron 08590 SSER #2, Clarification of what p.

p. 2-39 referred to Kane 08739 SSER #2, Seismic Shakedown S2.5.4.5.6 (identification of S's) 11/17/82 Chen 08996 SER, Underground Piping S1.12.10.

S3.9.3.1.

SSER #2, S3.9.3 @f R

v Kane 08998 SSER #2, S:

S2.5.4.4.5. X S2.5.4.5.6.2. n S2.5.4.7.

S2.5.4.8.

Table 2.8 Figure 2.1

p. 2-39 A

DATE WITNESS TR. (S)SER Section HEARING MATTER 11/17/82 Dr. Weeks 09148 SSER #2, S3.12.

11/19/82 Matra/ 09596 SSER #2, Service Water Pump Rinaldi S3.7 Structure S3.8.3 S3.8.3.2.

S3.8.3.5.

S3.8.3.6.

S3.8.3.7.

S3.8.4.

53.8.5.

Poulos 09596 SSER #2, S2.5.4.4.1 S2.5.4.5.2 S2.5.4.5.3.

S2.5.4.6.1.1.

S2.5.4.6.1.2.

Figure 2.8 Figure 2.9 Figure 2.12 Figure 2.13 Kane 09596 SSER #2, S2.5.4.6.3.

S2.5.4.7.

S2.5.4.8.

Singh 09596 SSER #2, S2.5.4.1.3.

S2.5.4.2.

52.5.4.3.

DATE WITNESS TR. (S)SER Section HEARING MATTER Rinaldi 09599-09604 SSER #2, Corrections of SSER #2

p. 3-8

p. 3-9

p. 3-12

p. 3-13 Figure 3.1

p. 3-21 Rinaldi 09605 SER, S3.7.2.4.

Kane 09605 SSER #2, S2.5.4.4.1.

52.5.4.5.2.

S2.5.4.5.3.

S2.5.4.6.1.1.

S2.5.4.6.1.2.

Hood 09626 SER, 51.12.7 11/22/82 Kane 09783 SSER #2, S2.5.4.4.4.

S2.5.4.5.5.

Kane 09850 SER, S2.5.6.6.

(redirect) S2.5.6.7.

DATE WITNESS TR. (S)SER Section HEARING MATTER 11/23/82 Gonzales 10012 SER, Underground Piping /

Sl.9. (l) Permanent Dewatering Sl.12.4.

S2.4.6.1.

52.4.6.2.

S2.4.6.3.

SSER #2, S2.4.6.2.

S2.4.6.3.

S2.4.6.4.

S1.7. (as it pertains to 2.4.6) 12/7/82 Hood 10519-10520 SER, Diesel Generator Building Sl.12 Sl.12.5.

Kane 10520 SER, Diesel Generator Building I

S2.5.4.

SSER #2, S2.5.4.1.2.

S2.5.4.4.2.

S2.5.4.5.1.

S2.5.4.5.2.

52.5.4.5.4.

S2.5.4.5.6.

S2.5.4.6.3.

S2.5.4.7.

, S2.5.4.8.

.I I

I A

DATE WITNESS TR. (S)SER Section HEARING MATTER 12/8/82 Hood 10604-10612 SSER #2, Corrections of SSER #2

p. 2-23, drawing C-1493

p. 2-41

p. 2-45

p. 2-48

p. 3-42

p. 2-34

p. 3-26 Singh 10618-10619 SSER #2, S2.5.4.1.3.

52.5.4.2.

S2.5.4.3.

12/10/82 Rinaldi 11075 SER, Diesel Generator Building /

S3.8.3. Bearing Capacity S3.8.4.

SSER #2, S3.8.3.4.

S3.8.3.5.

S3.8.3.7.

Hood 11077-11079 SSER #2, Stability of subsurface S1.7 materials and slopes

$16, Item 22 Long-term monitoring of structure; cracks 2/17/83 Kane SSER #2, 12066 pp. 2-24 thru 2-34 Stamiris Contention 4A3 12070 pp. 2-17 and 2-23 Stamiris Contention 4C(a) 12070 pp. 2-23 and 2-40 Stamiris Contention 4C(a) 12071 pp. 2-34 and 2-35 Stamiris Contention 4C(c) e J

DATE WITNESS TR. (S)SER Section HEARING MATTER Rinadli Prepared SSER #2, Stamiris Contention testimony S3.7 4C(a), (c), (d) and (e)

-at p. 6, S3.8 following Tr. 12080 Hood Prepared SSER #2, Loose sands beneath testimony S2.5.4.5.5 service water piping at p. 4, following

.T r . 12144 t- _ _-- - _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _ . _)

N

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C y $S! c.:;s 8

g awn ' [:ly

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UNITED STATES OF AMERICA b~

AUC O NUCLEAR REGULATORY COMMISSION pocurrs a -

y staucE Bit.oca ,

bgcY.NLC Cv BEFORE THE ATOMIC SAFETY AND LICENSING BOARD

)

In the Matter of )

) Docket Nos. 50-329-OM CONSUMERS POWER COMPANY ) 50-330-OM

) 50-329-OL (Midland Plant, Units 1 and 2)) 50-330-OL

, CERTIFICATE OF SERVICE I, Lawrence P. Hampton, hereby certify that a copy of " Applicant's Proposed Findings of Fact and Conclusions of Law on Remedial Soils Issues" was served upon all persons shown in the attached service list by deposit in the United ,

States mail, first class, this 5th day of August, 1983.

M < / t Lawrence P. 1%mpton SUBSCRIBED AND SWORN g fore me this g Y day of h # ,

1983. /

g

} w m-

. NOTARY PUBLIC f!y Commission Expires July 8,1985

r- y .

w SERVICE LIST Frank J. Kelley, Esq. Atomic Safety & Licensing Attorney General of the Appeal Panel State of Michigan U.S. Nuclear Regulatory Comm.

Carole Steinberg, Esq. Washington, D.C. 20555 Assistant Attorney General Environmental Protection Div. Mr. Scott W. Stucky

,,_ 720 Law Building Chief, Docketing & Services Lansing, Michigan 48913 U.S. Nuclear Regulatory Comm.

Office of the Secretary Myron M. Cherry, Esq. Washington, D.C. 20555 Cherry & Flynn Suite 3700 Ms. Mary Sinclair 3 First National Plaza 5711 Summerset Street Chicago, Illinois 60602 Midland, Michigan 48640 Mr. Wendell H. Marshall William D. Paton, Esq.

p 4625 S. Saginaw Rd. Counsel for the NRC Staff Midland, Michigan 48640 U.S. Nuclear Regulatory Comm.

Washington, D.C. 20555 Charles Bechhoefer, Esq.

Atomic Safety & Licensing Atomic Safety & Licensing Board Panel Board Panel U.S. Nuclear Regulatory Comm. U.S. Nuclear Regulatory Comm. ,

Washington, D.C. 20555 Washington, D.C. 20555 Dr. Frederick P. Cowan Barbara Stamiris 6152 N. Verde Trail 5795 North River Road Apt. B-125 Route 3 Boca Raton, Florida 33433 Freeland, Michigan 48623 Mr. D. F. Judd Jerry Harbour Babcock & Wilcox Atomic Safety & Licensing P.O. Box 1260 Board Panel Lynchburg, Virginia 24505 U.S. Nuclear Regulatory Comm.

Washington, D.C. 20555 James E. Brunner, Esq.

Consumers Power Company Lynne Bernabei 212 West Michigan Avenue Thomas Devine Jackson, Michigan 49201 Louis Clark Government Accountability Project Steve Gadler, At The Institute For Policy Studies 2120 Carter Avenue 1901 Q Street N.W.

St. Paul, Minnesota 55108 Washington D.C. 20009

ML20024E343

Text

Enclosures:

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