ML19331A945
| ML19331A945 | |
| Person / Time | |
|---|---|
| Site: | Midland |
| Issue date: | 07/02/1979 |
| From: | Gibbs M ISHAM, LINCOLN & BEALE |
| To: | Cowan F, Kornblith L, Smith I Atomic Safety and Licensing Board Panel |
| References | |
| NUDOCS 8007240533 | |
| Download: ML19331A945 (1) | |
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% G Ivan W. Smith, Esq. Mr. Lester Kornblith, Jr.
Atomic Safety and Licensing Board Atomic Safety and Licensing Board U.S. Nuclear Regulatory Commission U.S. Nuclear Regulatory Commission Washington, D.C., 20555 Washington, D.C. 20555 Dr. Frederick P. Cowan THIS DOCUMENT CONTAINS 6152 N. Verde Trail Apt. B-125 POOR QUAUTY PAGES Boca Raton, Florida 3343a Re: Consumers Power Company (Midland Plant, Units 1 and 2) Docket Nos. 50-329, 50-330 Gentlemen: Enclosed are three interim reports submitted by Consumers Power Company to the Nuclear Regulatory Commission pursuant to 10 C.F.R. S50.55 (e) . The report concerning the settlement of the diesel 5 generator foundations and building includes an attachment which ref- - crences certain figures, drawings and charts; copies of these attach-ments will be provided to members of the Atomic Safety and Licensing _ Board and any party upon request. Very truly yours,
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Martha E. Gibbs h MEG bc cc: Service List Enclosures soovuo 533 G
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Ceneret offices: 1943 West Parnell Reed, Jackson, Michigan 49201 * (517) 788 4453 ,
. June 25, 1979 Hove-17h-79 Mr J G Ecppler, Regional Director Office of Inspection and Enforcement US Nuclear Regulatory Ccr'nission Region III 799 Roosevcit Rcad Glen Ellyn, IL 60137 MIDLA!'D !!UCLEAR PLA'IT U'i!T ::01, DCCKE"' NO 50-329 U'i!T : 0 2, DCCt. 30 50-330 SE?ILE!E'T OF DIESEL GE'iERATOR FOUNDATIONS A'iD BUILDING
References:
- 1. S H Hovell letters to J G Keppler; Midland Nuclear Plant; Unit No 1, Docket No 50-329; Unit No 2, Docket No 50-330:
Settlement of Diesel Generator Foundations and Building; (a) Serial Hove-183-78; dated Septe=ber 29, 1978 (b) Serial Heve-230-78; dated November 7,1973 ' (c) Serial Hove-267-78; dated Dece=ber 21, 1973 (d) Serial Hove-1-79; dated January 5, 1979 - (e) Serial Hove-58-79; dated February 23, 1979 (f) Serial Hove-132-79; dated April 30, 1979
- 2. G S Keeley letter to J G eppler; Midland Pro.'ect - _.
Docket No 50-329 and 50-330; ?esponse to 10 C R 50 5h . Request on Flant Fill; Serial 6925; dated April 2h, 1979 This letter, as vere references 1 (a) through (f), is an interi: 50 55(e) report on the settlement of the diesel renerator foundations and buildinc.
"'he enclosure ('! CAR 2h, Interim Report #6) provides detailed supplenental info =c.ticn to reference 2 in regard to ra.nedial actions planned for fill under c:tercry 1 structures where the soil intestigation has revealed that the fill has not been adequately conpacted. The preparation of the enciesed Interin Report (dated June 11, 1979) was ti~ed to allow NER reviev prior te the neeting scheduled for July 10, 1979 in Ecthesda. Sub.tequent to the preparation of the Interi: Report, the renedia' actiens contained therein have undergene continuint; design revievs, inclucing an evaluation by Doctors Peck, Hendron and Daviscon. A1:ematives to the remedial measures presented in the Interim Report are presently beinc considered including the use of a per=anen'. devatering systen in lieu of the chemical g-outing of sands to eliminate any potential for liquefaction.
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Hove-17h-79 With respect to the temporary air line in the tank farm area which was leaking, < 4 several actions have been taken or vill be taken. The temporary line has been abandoned in place with a new tedporary line installed in the stem tunnel. The top three to four feet of soil vill be removed prior to . resuming backfill, the tank farm area has been mapped to locate all seepage areas, and an engineering evaluation vill be made to deter =ine the condition of the fill material. An inspection pit vill be dug in the vicinity of the leak. "he above was in progress or planned and was discussed during the NRC inspection exit meeting of May 17, 1979 Another interim report vill be sent on or before September 5, 1979 [~ C ^m -
Enclosure:
MCAR 2h, Settle =ent of the Diesel Generator Foundations and Building, (Insufficient Compaction in Plant Area Fill Related to Seismic Category I Structures and Facilities), Interin Report #6, dated June 11, 1979 CC: Director, Office of Inspection & F.nforce=ent Att: Mr John G Davis, Acting Director, USiRC (15) Director, Office of Management Infor=ation and Progrs= Control, USNRC (1)
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3CC: JL3 acon, M-1085A WR31rd, JSC-2163 RLCastleberry, 3echtel AA TCCooke, Midland J1Corley, Midland LADreisbach, Bechtel-Midland - Dehorn, Midland CAHunt, Pik-2093 GSKeeley, P1h h083 MJFoschik, M-890A SW'!arguglio, JSC-22CA PE!artine:, Bechtel AA D3 Miller, Midland JF::evGen, 3echtel-Midland M bbs, IL&3 Doute: 3IC!/SHH/ File 0.h.9 20
n. Bechtel Associates ProfessionalCorporation d_
SUBJECT:
MCAR 24 (issued 9/7/78)_ Settlement of the Diesel Generator Foundations and Building (Insufficient Compaction in Plant Area Fill Related to Seismic Category I Structures and Facilities) INTERIM REPORT 6, . DATE: June 11, 1979 PROJECT: Consumers Power Company Midland Plant Units 1 & 2 Bechtel Job 7220 Introduction The soil investigation under Seismic Category I structures founded on plant area fr i has been completed. It has been identified that the fill under some of these structures has not been adequately compacted. This report sununarizes the soil investigation and describes the details of remedial actions planned for portions of the auxiliary building, the feedvater isolation valve pits, the part of the service water pump structure founded on insufficiently compacted backfill, the Seismic Category I storage tanks on fill, and the diesel generator building. - The current status of the diesel generator building sectiements is also included in this report. .- Anviliarv Building and Feedwater Isolation valve Pits - They Parts of the auxiliary building are founded on plant area fill. are the railroad bay on the north side, and electrical penetration The rest areas of for Units 1 and 2 and the control tower onThe the areas southfounded side. on, plant the building is founded on glacial till. The area fill and glacial till are identified in Figures 63 and 64. feedvater isolation valve pits for both Units 1 and 2 are founded on plant area fill. The feedwater isolation valve pit plans are shown in Figure 63 and a cross section is shown in Figure 70. A) Auxiliary Building Electrical Penetration Areas, Control Tower, and Feedwater Isolation Valve Pits
- 1) Sequence of backfill placement structures, Due to the variation of foundation levels of adjacent the fill in this area was placed in stages as the construction of the auxiliary building progressed. Temporary earthen ramps and concrete mudmats were placed at some elevations to facilitate construction. Due to the complexity of fill operations, The description the sequence of fill placement was investigated.
follows.
Bechtel Associates Professional Corporation MCAR 24 Interi:n Report 6 @ June n , 1979 Page 2 . The base excavation for the power block area is shown in Figures 65 and 66. Some local areas (outside the limits shown in the drawing) on the south side of the reactor building tendon galleries and on the south side of the anv414=ry building along H-line were excavated. The wedge-shaped excavation next to the anwf14mry building and tendon galleries was fined with 4 lean concrete, as were the areas excavated outside the limits shown in Figure 65 as mentioned above. The top elevation of lean concrete in these areas was approximately 583', with a sudmat placed between column lines H and K from approximately the 4.6 line to the 8.6 line (Figure 63). The backfill for the electrical penetration areas and the feedvater isolation valve pits was placec up to an approximate elevation of 592' during the sunmar and fall of 1974. The major difference between Unit 1 and 2 fill placement up to an approrimate elevation of 592' in the electrical penetration area and feedwater isolation valve pit area was that the Unit 2 area was used as an access ramp for cranes, concrete trucks, pumps, etc, whereas the access in the Unit 1 area was a one-time crane access for the Unit 1 liner plate erection. The control tower area was covered, heated, and backfilled in -" the winter of 1974-75 up to an elevation varying between 590' l and 592'. A lean concrete mudmat was then placed up to el 593'. All three areas were backfilled during the summer and fall of 1975 up to el 609' as fonows. The Unit 2 electrical penetration area was backfilled first and was used as a ramp for trucks _ and equipment for compacting sand in the control tower area. The sand placed under the control tower extented out into the Unit 1 electrical penetration area by a few. feet. The backfill on the Unit 1 side lagged behind the other two areas by a few weeks. The feedwater isolation valve pit area was backfilled with lean concrete to el 615'-6", but the backfill for Unit 2 was kept low for construction of the buttress access shaft and,was backfilled later.
- 2) Soil Exploration Twelve soil borings were made in this area to evaluate the foundation backfill materials. The locations of these borings are shown in Figure 67. A cross section is shown in Figure
- 69. Based on the borings, the supporting soil conditions under the control tower, electrical penetration areas (Units 1 and 2), and feedvater isolation valve pits (Units 1 and 2) are summarized as fonows.
Bechtel Associates ProfessionalCorporation NCAR 24 % Interim Report 6 June 11, 1979 . Page 3 Structures Boring Suoporting Soil Conditions Auxiliary Building Control AI-6,9,18 Medium dense to very dense sand backfill over tower dense glacial till with the exception of a local void under the concrete mudmat at el 590' to 589' at boring AI-9. Unit 1 AI-7,15 Generally dense to very dense sand backfill electrical with occasional layers of loose sand and soft penetration clay. The backfill is underlain by dense area glacial till. Concrete was also used as backfill. A layer of concrete was encountered from el 583.5' to 580.1' at boring AI-7. Unit 2 AI-8,19 Medium dense to dense sand backfill with electrical occasional medium stiff clay layers over dense penetration glacial till, with the exception of a loose area to very loose sand pocket backfill encountered between el 596.5' to 600.5' at boring AI-19. ' Concreta was also used as backfill. Feeedwater Isolation Valve Pits Unit 1 AI-5,11 Loose to dense sand and medium stiff to very _ (adj acent) stiff clay backfill with occasional soft zones over dense glacial till. Concrete was also used as backfill.
- Unit 2 AI-4,3,12 Loose to dense sand and medium stiff to very (adj acent) stiff clay backfill with occasional soft zones over dense glacial till. Concrete was also used as backfill. A layer of concrete was encountered from el 585.2' to 575.5' at boring AI-4.
The boring logs for these areas (taken from FSAR Appendix 2A) are given in Appendix A of this report. I 1 r s-- ,_
m Bechtel Associates Professional Corporation 5 MCAR 24 Interim Report 6 ' June 11, 1979 Page 4
- 3) Description of Deficiency The fill material under the control tower is adequate except for the void under the concrete mudmat as mentioned in the description of soil exploration. Borings indicate that liquefac-tion will be of no concern in this srea.
From the boring logs, it has been concluded that approximately the top 15' of the backfill material under the electrical penetration areas and valve pits has not been sufficiently compacted. It is estimated that the extent of inadequate fill extends under the entire electrical penetration area for Unit 1 and only part of the area under Unit 2.
- 4) Corrective Action For the control tower, pressure grouting will be used as needed to fill the void under the mudmat.
The unsuitable backfill material beneath the auxiliary building electrical penetration areas and feedwater isolation valve , pits will be removed and replaced by lean concrete having a minimum compressive strength of 2,000 psi. Field tests of the , exposed fill material will be conducted to determine the actual extent of excavation and replacement of the fill material. The remedial action for the electrical penetration areas and I the feedwater isolation valve pits will be carried out in four - phases as follows. a) Preparatory Work Valve Pit Supoorts - A temporary support for the feedwater isolation valve pits (Units 1 and 2) will be provided. They will be supported externally from the turbine building and buttress access shaf t as shown in Figure 70. External Support for Electrical Penetration Area - As a result of dewatering, the electrical penetration area may experience loss of support due to lowering of the water l table and soil settlement. A static structural analysis ' has been performed assuming that the electrical penetration areas are supported from the control tower by cantilever action. Figures 71 and 72 show the finite element models used for the analysis. The results of the analysis are being evaluated. If it is determined that temporary
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- - Bechtel Associates Professional Corporation MCAR 24 Q Interim Report 6 June 11, 1979 Page 5 external support is required for the electrical penetration area for Unit 1, a steel girder resting on the containment ring girder and turbine building crane column (as shown in Figure 73) will be provided. However, the assumption of a fully cantilevered structure is very c.onservative because some support will be provided by the soil below.
The excavation will not extend under the entire penetration area before temporary supports are provided from below. Instrumentation and Monitoring - Instrumentation will be installed to monitor the movements of electrical penetration areas during dewatering and excavation operations. Horizontal and vertical movements will be measured at selected locations on the structures. Specific locations in the control tower and electrical penetration areas will be monitored for cracking of concrete. These locations will be selected based on the results from the static analysis described in the discussion of external support. b) Dewatering The present ground. vater table and the present water ' level in the cooling pond are at an approximate elevation of 627'. Prior to and during the removal and replacement of the backfill, the electrical penetration areas and feedwater isolation valve pits will be continuously dewatered to provide a dry condition. An area dewatering system capable of lowering the groundwater to el 580' will be installed (Figure 74) . The water will be diverted _ back to the cooling pond through the existing storm drainage system. Any ground water trapped in the excavated area vill be removed by local dewatering during the excavation. c) Additional Temporary Support If the instrumentation data indicate a differential building movement which approaches 1/2 inch, or if the crack monitoring indicates cracks which approach 0.04 inch in width, an engineering evaluation will be made to determine the necessity for additional temporary support I measures. l 1 l
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, ,. - I Bechtel Associates Professional Corporation MCAR 24 Interim Report 6 June 11, 1979 Page 6 d) Excavation and Concrete Backfilling A general plan and a schematic detail of excavation and concrete backfilling is shown in Figure 75.
When the general groundwater table has been lowered by dewatering to an approximate elevation of 600', an access shaft (approximately 20' x 20') wi n be dug from el 634' (grada elevation) to el 603' . A tunnel win be made underneath the feedwater isolation valve pits as a continua-tion of the access shaft. ._ The temporary support system will be provided under the ends of electrical penetration areas before undertaking mass removal of backfill material. The temporary support , system win consist of jacked piles, caissons, or concrete piers installed along the edges of the electrical penetration areas. Soldier piles, caissons, or concrete piers with a nondeteri- - orating type of lagging material win be used to secure
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the soil under the turbine building and control cover. This lateral suppert will prevent soil movement under the ~ adjacent turbine and control buildings during underpinning operations. The lateral support will be designed for a hydrostatic head from el 627' to the bottom of mass excavation tender the structures. The lateral support will also be designed for earth pressure loads from soil - beneath these buildings. The depth of the initial excavation where the earth is not supported will not exceed 4 feet if it is within 6 feet of the K line and 5.25 line for Unit 1 and 7.85 line for Unit 2 (Figure 75). Otherwise, a maximum depth of 6 feet will be used. After the initial excavation, lagging will be installed and back-packed. The lagging along the K line and 5.25 line for Unit 1 and 7.85 line for Unit 2, located below el 600', will be grouted. Excavation and removal of unsuitable material vill be done by manual or mechanical means. Conventional tools, such as rock splitters and demolition tools, will be used to dislocate and/or remove hardened material during excavation. Excavation will not proceed to a depth greater than 3 feet below the previously grouted lagging. Proper precautionary measures wi n be taken to prevent any movement of foundation material outside the excavation area.
" Bechtel Associates Professional Corporation MCAR 24 Interim Report 6 Juna n. 1979
- Page 7 Af ter removal of an inadequate fill material, the excavated area win be backfilled with lean concrete having a minimum strength of 2,000 pai. Concrete vin be poured in lift thicknesses of 5 feet ==r4==, with the exception of the first lift being not more than 2 feet thick.
Successive lifts will be doveJed into the preceding lift. The topmost lift win be within 6 inches of the bottom of the existing slab. The remaining void between the lean
- concrete backfin and the foundation slab win be either dry packed or pressure grouted. A two-inch gap will be provided between the lean concrete backfill and the adjacent structures (the containment Jailding and the turbine building) by using ethafoam or similar joint separation materials.
- 5) Other Activities Since Last Report a) Crack Monitoring Crack maps for these buildings are shown in Figures 76 through 79. .
b) Seismic Analysis The removal of the unsuitable fill and the replacement of lean concrete under a portion of the auxiliary building foundacian mac would increase the effective mass of the foundation. This increase in foundation mass may not significantly impact the overan seismic analysis results. _ However, because of minor changes in the mass value and soil-structure interaction parameters, a slight frequency shift may be expected. A seismic analysis will be performed to evaluate the degree of change of the system frequencies by modal analysis and deterrine if the variation is . significant.
- 3) Auxiliary Building Railroad Bay
- 1) soil Exploration Three borings (AX-1, 2, and 10) were made in this area. The locations are shown in Figure 67. The cross sections of borings are shown in Figure 68. Based on the borings, the the supporting soil conditions can be sununarized as medium to very dense sand backfill over dense glacial till. Concrete was also used as backfill. It has been determined that the fill can safely withstand the imposed loading. The liquefaction potential of sand in this area has been evaluated and is being reviewed by the soil consultants.
Bechtel Associates Professional Corporation MCAR 24 Interim Report 6 June 11, 1979 @ Page 8
- 2) Description of Deficiency The upper 18 feet of sand backfin may have liquefaction potential, based on the boring records.
- 3) Corrective Action If there is liquefaction potential, chemical grouting win be used to stabilize the sand.
Service Water Pump Structure
- 1) Sequence of Backfill Placement Excavation to an approximate elevation of 586' for the service water pump structure was made in late summer 1976. A few pockets of loose sand encountered in the bottom of the excava-tion were removed. The excavation was devatared. The lower portion of the structure on the original ground was built during the fa n and winter of 1976-77. Backfin from al 590't to el 616' on the north side and under the cantilever section (Figure 81) was placed between January and April of 1977 under heated enclosures. The slab and walls for the cantilever portion were placed in the spring and summer of 1977. Back-fill from al 616' to 634' in the area of the service veter pump structure was completed in late summer and fan of 1977 escept for one small area adjacent to the northwest side of the building (approximately 10 to 12 feet deep). This area, expanding from approximately the center of the building to the northwest corner, and then along the north side for a few feet, was left open during the winter and was backfilled to _
l el 634'-0" in the fan of 1978. l
- 2) Soil Exploration l
Except for a portion of the structure to the north, the major part of the service water pump structure is founded on natural i soil material as shown in Figure 80. The northern section of I the structure is* located on backfill material, as shown in Figure 81. Eleven borings were made in the service water pump l structure area. The boring logs for these borings are given in Appendix A. The locations of these borings are shown in l Figure 67. A cross section has been established as shown in l Figure 82. Based on the boring records, the supporting soil l condition for backfill can be summarized as soft to very stiff l clay and loose to very dense sand backfill over medium dense to very dense sand over glacial till, vich the exception of 2.5 feet of loose sand encountered between el 601.5' and 599.0' in boring SW-6.
q _ Bechtel Associates Professional Corporation MCAR 24 Interia Report 6 June 11, 1979 Q Page 9
- 3) Description of Deficiency Some areas of the fin material under the northern part of the structure have not been sufficiently compacted.
The reason for no significant settlement is that the existing dead loads from the portion of the structure over the fill material are being supported by the rest of the structura founded on natural material through cantilever action. A static analysis of the structure indicated that the total design loads cannot be supported by the main structura through cant 11 aver action.
- 4) Corrective Action The option of piling under the north wall of the service water pump structure was chosen over the option of removal and replacement of ursuitable material for the fo nowing reason.
Any excavation and replacement of fin win requira devataring. It would be difficult to attain a dry condition benaath the service water pump structure by dewatering to permit excavation and backfilling operation because of the proximity of the structure to the cooling pond. Predrilled bearing piles will be placed under the north wall of the structure to carry the vertical load as shown in Figure 83. These piles win be concreta filled staal pipe pilas which will penetrate into the bearing stratum which occurs at an approximate elevation of 587 feet. The design capacity of the piles win be 100 tons. _ Borizontal loads will be carried by the deeper part of the structura founded on natural material. The. details of the connections of piles to the structure are shown in Figura 83. A test pils will be load tested in accordanca with ASDf D 1143 to determine its capacity. The vertical stiffness (dynamic) will be determined analytically. All piles will be designed and installed in accordance with ACI 543.
Bechtel Associates Professional Corporation MCAR 24 $ Interim Report 6 June 11, 1979 . Page 10
- 5) Other Activities Since Last Report a) Building Settlement Based on the foundation data survey program, no increase in the settlement of the building has been observed from the settlement values reported in Figure 2 of Interim Report 5 of MCAR 24.
b) Seismic Analysis Results of a preliminary seismic analysis indicated that the use of piles under the north wall of the structure is feasible. Because of the change in the foundation design concept, a new' seismic analysis will be performed to evaluate the change in the seismic design forces and the floor response spectra. The new seismic model incorporates the modified design concept as follows. The soil-structure interaction - accounts only for the lower level foundation which is foundG on natural soil. In addition, a spring simulating - dynamic vertical pile stiffness is attached to the east side wall in the mathematical model. The upper level foundation, which is founded on the fill, is assumed free of contact with the foundation medium. The modified mathematical model consists of an assemblage of beam and _ i finite element plate members with masses lumped at floors and location of significant mass concentration. The seismic analysis technique and criteria used follow those specified in the FSAR Section 3.7, except that the composite modal damping values will be computed based on the stiffness weighting function technique. This method also provides an acceptable basis for seismic analysis per the NRC Standard Review Plan Section 3.7.2. The Bechtel Structural Analysis Program (BSAP) will be utill:ed to perform the analysis.
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. Bechtel Associates Professional Corporation MCAR 24 Interim Report 6 e June 11, 1979 m Page 11 Seismic Category I Tanks on Fill A) Borated Water Storage Tanks The tanks, when constructed, will be filled with water and monitored for settlement.
An inspection pit will be dug in the tank farm area and further soil investigation will be made in the area of the air-line leak. B) Baergency Diesel Fuel Oil Storage Tanks The tanks have been filled with water and the settlement monitoring of these tanks is being continued. To date, these tanks have not undergone settlement. Diesel Generator Building and Foundations
- 1) Description of Deficiency This has been described in detail in previous Interim Reports 1, 2, 3, 4, and 5 of MCAR 24.
- 2) Corrective Action Details of corrective action also were described in the previous ,
reports of MCAR 24. For portions of the fill under the diesel generator building having liquefaction potential, chemical grouting will be used - to stabilize the sand. I A procedure for chemical grouting of liquefiable sand is being developed. A sand test pit measuring approximately 20' ft 2 and 15' deep will be grouted. The sand will be dumped and leveled. No attempt at compaction will be made. Upon completion of test pic grouting, the pit will be avamined for the effectiveness of the grouting. The test pit will te er= mined using standard penetration tests (ASTM 15861 and visual inspections. Based upon the results of the test pit, a procedure vill be established so that grout will penetrate and cement the sands. The procedure developed from this test program will provide the pumping rate, pressure, etc, at which the grout will be applied.
m _' . . l Bechtel Associates Professional Corporation l 4 i MCAR 24 $ Interim Report 6 l June 11, 1979 , i Page 12 l l
- 3) Other Activities Since Last Report i a) Building Settlement and Preload Operation Figures 13, 14-1, 43, and 44 have been updated to show
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the settlement data for the diesel building and foundation as of June 1, 1979. The readings taken from the settlement markers indicated that settlement measurements were essentially stable during the last several weeks. No additional preloading is planned; however, the present level of preload will be continued for 6 weeks to better define a future dat-c for preload removal. Five rebound measuring instruments are being installed. Four of these instruments will be near
- each corner outside the building and one will be installed at the northeast corner of pedestal 4. Four additional borros anchors will be installed deep in the till (el 535')
for use as local benchmarks, which may also be used for rebound measurements. These borros anchors are to improve the existing survey accuracy to +0,01 inch. _ Effect on Project Schedule ,
- 1) Auxiliary Building Electrical Penetration Areas and Feedwater Isolation Valvs Pits Field activities for these corrective actions are scheduled to -
begin in July 1979. All activities are anticipated to be completed by July 1980. These corrective actions are not delaying the project system completion and testing schedule and therefore are not expected to impact the project schedule.
- 2) Service Water Pump Structure Field activity for this corrective action is scheduled to begin in August 1979. Completion of corrective actions is anticipated by January 1980. Current project schedule requirements for completion and testing of the service water supply system will not be delayed by this corrective action and therefore are not expected to impact the project schedule.
m _ Bechtel Associates Professional Corporation NCAR 24 @ Interim Report 6 June 11, 1979 ' Page 13
- 3) Seismic Category I Tanks l
a) Borated Water Storage Tanks The schedule impact for the filling and monitoring of the tank H has been analyzed based on sequential filling of completed ! tanks. This will allow the current project schedule system testing requirements to be met without impact to the project schedule. - b) Diesel Generator Fuel Oil Storage Tanks No delay in the completion requirements of this system is anticipated. The possible corrective actions for these tanks have sufficient schedule float to allow further investigation and analysis.
- 4) Diesel Generator Building and Foundations Based on our initial schedule analysis, the potential for a 2-month '
delay in the diesel ~ generator system completion was identified. ~ Our current analysis of refined construction and testing schedules -" indicates that the corrective action by soil preload will have no project schedule impact if the surcharge material is removed begin- _ ning August 15, 1979, as currently scheduled. Submitted by: ., - -3 '~ -_ - - - TY Reviewed by a Approved by: [ / Concurrence by t4 AG/js ! 6/6/6
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Generet Offices: 1948 West Parnell Road, Jeckson, Michigan 40201. (517h 7884453 June 20, 1979
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Mr J G Keppler, Regional Director Office of Inspection and Enforce =ent ,
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US Nuclear Regulatory Co==ission x ^- MW Region III 799 Roosevelt Road NN'%-{ u r f Glen Ellyn, IL 60137 MIDLAND NUCLEAR PLAl?f - Un1T HO 1, IECE2 no 50-329 UNIT NO 2, DOC 722 no 50-330 MAIN CO!; TROL PAEL, STATUS DISPLAY pat EL MODULES In accordance with the require =ents of 10 CFR 50 55(e), this letter conctitutes an inter 1= report on the status of discrepancies found in soldered co=ponents of the J201 Main Control Panel supplied by Magnetics. The attach =ents to this letter provide a description of the discrepancy, -, potential safety i=plications, investigation and planned corrective actions. Another report, either interim or final, will be sent on or before July 20, 1979
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Q pw& _ Attachments: 1. Quality Assurance Progrs=, Manage =eht Cerrective Action Report, MCAR-1, Report 28, Revision 2, dated June k,1979
- 2. MCAR-28, Interi= Report yl, dated June 7,1979 CC: Director of Office of Inspection and Enforce =ent Att: Mr John G Davis, Acting Director, USIEC (15)
Director of Office of Management Infor=ation and Progrs= Control US:RC (1)
.I a 6e 79 eG 22pS5'S
m ,. e BCC: JLBacon, M-1085A BWMarguglio, JSC-220A WRBird, JSC-2163 PAMartinez, Bechtel AA RLCastleberry, Bechtel AA DEtiller, Midland TCCooke, Midland WGMorin6, Bechtel AA JNewgen, Bechtel-Midland 3 J!.corley, Midland LADreisbacn, Bechtel-Midland MJSchaeffer, Midland File: 0.h.9.26 MEGibbs, IL&B GSKeeley, P-1k-h08B M' 9
, Attachm:nt 1 CwALITY ASSURANCE PROGRAM Hows-173-79
- MANAGEMENT CORRECTIVE ACTION REPORT MCAR1 REPORT NO.28 Rev. 2 6/04/79 Rev. 1 5/22/79 JOB NO. 7220 Q NO. 5.031 DATE Rev. 0 5/11/79 1 ' DESCRIPTION (including references):
NCR 2176 was written 5/11/79 to identify a problem with the Main Control Panel, Control Penal Section 1C14 furnished by Magnetics on P. O. 7220-J-201 Revision 6.* Five (5) wire t:rminations (on the Status Display Panel Module) were found to be loose from their c 1dsred connection to the individual switches as follows: See Sheet 2
' RECOMMENDED ACTION (Optional) ,
- 1. Determine what effect the loose wires could have on Plant safety if uncorrected. b
- 2. Inspect all other components by Magnetics for this chkracteristic (100"). d
- 3. Decemine why tae Magnetics Quality Assurance Program and Bechtel Procurement Supplier Quality Program did not detect this discrepant material.
Continued on Sheet 2 REFERRED TO El ENGINEERING O CONSTRUCTION COA MANAGEMENT O El PROCUREMENT 6/4/79 ISSUED BY M.I1Lh neer A w utR uJc!CA En ya Date ll REPORTABLE DEFICIENCY I Client reported this item NOTIFIED CUENT 5/11/79 c
!ot the NRC 5/29/79.
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AUTHORIZED BY ! oate l STANDARO OtSmtBUTION ADDITIONAL. DISTRIBUTICN AS APPROPRIAE
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G ' ' Attachmtnt 2 Hov2-173-79 - a ' Bechtel Associates Professional Corporation g
Subject:
MCAR #28 Interim Report 1 Date: June 7, 1979 Project: Consumers Power Company Midland Plant Units 1 & 2 Bechtel Job 7220 Introduction This report is submitted to advise regarding the interim status and course of action required pursuant to MCAR #28 and Bechtel NCR #2176. Description of Discrepancy Bechtel field inspection of the installed ESFAS status display light
- modules on panel 1C14 revealed discrepancies regarding the soldered wire connections as follows:
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Switch Terminal Problem Description ISV-0127 G Not soldered G Loose solder joint [ 19V-0127A Cold solder joint _. ISV-0127A C IMO-1257 G Not soldered , Not soldered IMO-5336A A IMO-0912 G W1.re touching movable member the wire connactions on the status display panel modules for panels IC14 and 2C14 were inspected by the QA manager of the vendor (Magnetics, a - division of Spang industries) and Bechtel engineering on May 22, .1979. This inspection has revealed the need for more thorough inspection for all status display modules on panels IC14, 2C14 and OC10. Following is the preliminary response to the recommended actions: ,
- 1. Determine what effect the discrepant material could have on plant safety if uncorrected.
From the electrical schemes and wiring diagrams we have determined that if these problems are uncorrected they could cause: a) loss of safety display indication b) false indication c) overheating and possible burn out of the voltage dropping resistor d) preliminary findings show there is no likelihood of blowing a fuse in the control circuit because the dropping resistors are connected in such a way that any grounding or touching of the moveable parts will cause the voltage dropping resistors to overload and overheat and possibly burn out.
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,- Juna 7, 1979 l ,, MCAR 28 INTERIM REPORT 1 None of the above conditions is likely to disable the' control 33 circuit.
- 2. Examine other soldered components by Magnetics. Other components by Magnetics include the following:
a) light display units for panels IC14, 2C14 ar.d OC10. b) amphenol connectors for IC14 and 2C14 light display units. There are no amphenol connectors for panei OCIO. c) Resistor banks for OC10, IC14 and 2C14 light display units. d) Nonsafety related digital indicators. Light display units for panel IC14 and 2C14 are detachable and have been shipped back to Magnetics, the panel vendor, for necessary inspection and corrections. - The other components listed above will be checked in the field per the schedule which is presently being established between Bechtel and Magnetics.
- 3. Determine why Magnetics Quality Assurance Program and Bechtel Procurement Supplier Quality Program did not detect this discrepant material.
a) Magnetics Quality Assurance Program: A specific, detailed inspection plan for soldered connections was not a part of QA program, which resulted in an inadequate inspection of sol- __ dered connections. b) Bechtel Procurement Supplier Quality Program: Bechtel Procure-ment Supplier Quality Program calls for random surveillance r inspection only. Further, supplier quality representative l inspection might not have been adequate because of lack of ~ detailed inspection criteria. .
- 4. Determine if a functional check would have revealed the above discrepant conditions. -
A functional test of the status display lamp assemblies was per-
. formed and was co-witnessed by Bechtel SQR and Bechtel engineering.
This test indicated that all functions were performed satisfac-torily. It is, therefore, concluded that a functional test of these assemblies or other components would not necessarily detect soldering deficiencies.
- 5. Based on the above 4 items determine reportability under 10 CFR 50.55e by May 25, 1979.
Because of the indeterminate nature of the possible failure modes and therefore the possibility that safety related circuits may have been rendered inoperable, it is suggested that this problem should be considered reportable under 10 CFR 50.55e.
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Pcr,s 3 of 3 - ( , MCAR 28 INTERIM REPORT o ' e
; '6. Probable Cause(s)
Present investigation indicates that lack of specific detailed manufacturing and inspection procedures for soldering operations was the probabic cause of the discrepant material. The supplier used general type procedures which lacked the required amount of 3 - detail to assure the level of quality required. Although a functional test of the status display light assemblies was performed and indicated satisfactory results, the nature of the problem appears to be undetected by functional test.
- 7. Corrective Actions The following corrective actions will be taken to prevent recur-rence of the discrepant material.
a) Require Magnetics to submit a comprehensive, detailed manu-facturing and inspection program for soldering practices. b) Magnetics to perform 100% reinspection of all soldered wire terminations and connections for the status display light assemblics and associated components and devices. c) Bechtel field quality control (QC) to perform inspection at completion of Item 2. Bechtel supplier quality representative (SQR) to perform 100% inspection of modules at the supplier's plant prior to shipment to jobsite. d) Bechtel procurement supplier quality department (San Francisco) has issued a supplier quality action request to all offices j and supplier quality representatives requesting investigation of their suppliers for similar problems. Upon receipt and < review of the responses, procedures will be developed to provide a comprehensive supplier surveillance program. l Forecast Date on Corrective Actions _ A schedule for the corrective actions will be proNded in interim report no. 2. , , Submitte y M N-/- -
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- Approved by: M .,
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l June 20, 1979 Hove-175-79 Mr J G Keppler, Regional Director Office of Inspection and Enforcement Region III US Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137 MIDLAND NUCLEAR PLANT UNIT NO 1, DOC E NO 50-329 UNIT NO 2, EcCKET NO 50-330
. I4PACI' TZ:;ireu - M GRINNELL SUPPLIED MAIN FEED PIPE In accordance with the requirements of 10 CFR 50 55(e), this letter constitutes an interim report on the status of the main feedline pipe spools supplied by ITI' Grinnell and which have some impact values not '
acceptable to the ASSE Boiler and Pressure Vessel Ccde. . The attachments to this letter provide a description of the discrepancy, , potential safety implications, investigation and planned corrective actions. - The main steam and main feed piping =aterial test results were reviewed on June 14, 1979 at m Grinnell in Kernersville, NC. The following was determined: _
- l. As reported by M Grinnell, Heat N32762 did not meet Charpy impact test requirements at 30 F. ,
- 2. Heat L20h79 vas accepted by IIT Grinnell on the basis of a subsequent heat treatment and a third test. The subsequent heat treat of the test samples was in a laboratory furnace.
3 One spool from Heat N32762 required bending, using Grinnell procedures which require elevated temperatures in the bend area. Sa=ples cut fro = the spool ig the heat affected area did not =eet Charpy test require-ments at 30 F. This spool is on" hold" at Grinnall. It is our interpretation that pipe can be impact tested a third time according to SA-106/SA-530 if a thermal treatment is utill::ed to i= prove the fracture properties of the as-rolled material. Tube 7qe z2G3h i
e _ 1 2 , Bowe-175-79 Fellow up actions include obtaining: 3
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- 1. A disposition of,the one heat (N32762) which had unacceptable fracture properties at 30 F. ,
- 2. A rationale for the retesting and acceptance of heat L2CA79 which had ASME Section III Code acceptable fracture properties after stress relief heat treatment.
3 A disposition of three spools subjected to the bending process. Further status of these actions will be provided in the next interim (or final) report which vill be submitted by August 1, 1/T9
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Enclosures:
(1) Management Corrective Action Report NCAA-1, Report No 29, Revision 1, dated May 25, 1979 (2) MCAR-29, Interim Report No 1, dated June 13, 1979 CC: Director of Office of Insnection & Enforcement Att: Mr John G Davis, Act;ing Director, USNRC (15) Director, Office of Management Information and Program Control, USNRC (1) _< l - \ BCC: JLBacon, M-lO85A RCBauman, Plk 412 WRBird, JSC-216B ~ AJBirkle, P2k-511 RLCastleberry, Bechtel AA JLCorley, Midland , LADreisbach, Bechtel-Midland GSKeeley, P14 kOSB BhMarguglio, JSC-220A DBM111er, Midland kT,Moring, Bechtel AA JFNewgen, Bechtel-Midland RLTeuteberg, Pik kl8 Albbs, IIAB File: 0.4 9 27
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.- QL..LITY ASSURANCE PROGRAM MANAGEMENT CORRECTIVE ACTION REPORT MCAR1 REPORT NO. 79 May 25, 1979 Rev. 1 JOB NO. 7220 Q NO. 4. 383. 4. 393 DATE w y ??- 1070 I ' DESCRIPTION (including references): 1 On May 21, 1979, IIT Grinnell notified Bechtel that nine (9) pipe spools fabricated from Heat No. N32762 failed to meet the physical impact requirements for the material.
'the nine (9) spools identified are for the Feed Water System as listed below:
1-ELB-1-S-638-13-3 1-EU-2-S-638-13-5 2-ELB-1-S-639-13-3A 1-ELB-2-S-638-13-3 1-ELB-2-S-638-13-6 2-ELB-2-S-639-13-3 1-ELB-2-S-63 8-13-4 2-ELB-1-S-639-13-3 2-ELB-2-S-639-13-4 NCR 2211 has been written and tags applied to identify these spools.
' RECOMMENDED ACTION (Optional)
- 1) All impact tested materials furnished by ITT Grinnell should be investigated to determine that acceptable test results can be related to the materials and the material condition furnished.
- 2) Those corrective actions taken by ITT Grinnell to comply with procurement documents subsequent to the non confor=ance identified in QA Flyer 76-F8, dated 12/15/76 should be e::a=ined. Continued on Page 2 02 ENGINEERING O CONSTRUCTION OOA MANAGEMENT O REFERRED TO O PROCUREMENT ISSUED BY AoLLM j
{ %< Protect OA Engcier Date Potentially Reportable I NOTIFIED CLIENT 5/22/79 Il REPORTABLE DEFICIENCY ate - l O NO O YES / Protect Manager Dare g l , lil CAUSE
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CORRECTIVE ACTION TAKEN , iki isW" d!Nl L MAY 3 0 379 QUAUU ASSilBAEE AUTHORIZED BY oat. STANDARD OtSTRIBUTION ADOmONAI. DISTRIBUTION . AS APPROPRIATE FORMAL REPORT TO CLIENT
- Date O ' "o'I"!'" "
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eroct CORRECTIVE ACTION IMPLEMENTED AAo raanct ere=Aro.s un.aota anaso.eaccuacucur uca AAO Pn0 CUM u(NT u.mAGEn paCu PROCUR(ut4T uCA AAO uGA OF f NGast tRosG W SUPPutR QUAUTY uGA AAC uGR OF CONSIMuCTos V':RIFIED BY _ __ _ _ _ __nm_
e . D . ', 1 MANAGDENT COP.RECTIVE ACTION REPORT l l REPORT 29. Rev. 1 Page 2 Recomended Action - continued. )
- 3) A review of ITT Grinnell records for impact tested materials should be perfomed. The review should address test results, the number of tests performed, that test samples are representative of the fabricated material and condition, that the temperature at which tests were perfor=ed was correct and any additional factors which would affe<t the acceptability of the test results.
- 4) Based on the results of item 1 thru 3 above, analyze the effect the identified materials could have on plant safety if uncorrected.
- 5) Based on items 1 thru 4 above, evaluate reportability under 10 CFR 50.55(e) by June 14, 1979. The PQAE and Project Manager should be notified i=cedi-ately when the reportability status is determined.
- 6) If the material is found to be unsatisfactory for its intended use, in-plement those corrective actions necessary to assure that the completed systems will meet FSAR comitments.
- 7) State what steps ITT Grinnell has taken to prevent recurrence.
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i. m. Bechtel Associates Professional Corporation Attachtent to D*f-7767
SUBJECT:
HCAR 29 $ INTERIM REPORT 1 , DATE: June 13, 1979 PROJ ECT: Consumers Power Company Midland Plant Units 1 & 2 Bechtel Job 7220 Description of Discrepancy Nine pipe spools, fabricated from ASME SA106, Gr B pipe, Heat N32762, failed to meet the physical impact requirements for the material in accordance with AS!E Section III code criteria. The NRC identified these spools during a review of Grinnell documentation. Grinnell subsequently notified Bechtel of the potentially reportable problem. Potential Safety Implication A potential safety problem would exist if inadequate material impact toughness properties at low feedwater temperatures resulted in, or contribute to, a main feedwater line break. Investigation During an NRC audit of Grinnell on February 26, 1979 through March 1, ~ 1979, it was discovered that ASME Charpy in: pact test procedures were not ~ followed for Heat N32762 and, therefore, the results are not acceptable. The specific code requirements are as followst. l In accordance w1th NB 2332(1) of ASME Section III, test three Cv speciuens
- at a temperature lower or equal to the lowest service temperature. All ,
three specimens shall meet the requirements of Table NB 2332-1. l According to Table NB 2332-1, the required Cv (Charpy V notch test) values for piping are as follows: Nominal wall thickness 1.ateral eransion (mils ( 5/8" or 1 css No test required - Over S/8" to 3/4" (inclusive) 20 Over 3/4" to 1-1/2" (inclusive) 25 Over 1-1/2" to 2-1/2" (inclusive) 40
d Bechtel Associates Professional Corporation t Attachw.nt to BIC-7767 MCAR 29 $ Interim Report 1 June 13, 1979 , Page 2 of 3 Subarticle NB-2350 of ASME Section III permits one Charpy V-notch impact retest (consisting of two additional specimens taken as near as practicable to the failed specimens) at the same temperature to be conducted, provided the following. a) The average value of the test meets the minimum requirements. b) Not more than one specimen per test is below minimum, c) The specimen not meeting the requirement is not lower than 10 ft-lb or 5 mils below specification requirements. Contrary to the above, for Heat 32762, Grinnell had performed four separate tests as identified below: a) 19151: Test voided because specimen criented incorrectly b) 19676-1 Results: 21, 40, and 45 mils (The minimum requirement is 25 mils for a material with a nominal wall thickness of 0.937 inches.) c) 19676-3 Results: 21, 40, 45, 25, and 18. The last two were not noted as a retest, which was permissible, though Test 19676-1 indicated that only three samples were tested. The failing 18 mils value precludas a further test at the same temperature. d) A subsequent test was performed by the ITT Grinnell test laboratory with passina values at 29, 30, and 32 mils. This was a third test of the haat which is not allowed by the Code. 'This test was accepted by ITT Grinnell Industrial Pipe Inc. Cerrective Action The following actiont: bcm.- been initiated or completed to resolve this situation.
- 1) Bechtel and CPN l!! review all impact tested material docuecntation at Grinnell on J.no 24, 1979.
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c .- _ n Bechtel Associates ProfessionalCorporation - Attac9zent to EIC-7767 MCAR 29 Interim Report 1 Q June 13, 1979 Page 3 of 3 ,
- 2) In response to the recommended action item, Grinnell stated at a meeting with Bechtel and CPCo on May 31, 1979, that it would recommend SA333 in lieu of SA106B for services that require low impact temperature material in all future orders.
- 3) Additional data obtained by Grinnell indicate that there may be regions of heat-effected zone on hot-bend sections of the pipe which will not meet the minimum Charpy test requirements. This spool has not-been shipped from Grinnell. Grinnell has tested samples removed from the bend area itself during qualifications of the hot bend procedure which exceeded our minimum Charpy test requirements. Bechtel is pursuing this matter with Grinnell and will provide an update in the next interim report.
- 4) Bechtel originally specified that the feedwater pipe be supplied with a minimum Charpy test temperature of 30F. Bechtel has reviewed the minimum Charpy test temperature required for the specific heat-related spools. In accordance with Code definitions of minimum service temperature and the operating criteria for the applicable portion of the system, a minimum service temperature of 70F is ~
required. A minimum service temperature of 30F was originally
- specified, based on the minimum expected service temperature for any fluid piping system within the plant. This conservative value was specified for feedwater piping for ease and consistency in contract administration.
l Based on additional test data available at Grinnell for these specific heats, the material would exceed Charpy test requirements _ except for hot bend sections. Therefore, we believe that the
- reportable condition of the pipe is indeterminate at this time l
because the acceptability of the hot bend sections is uncertain. Forecast Data for Investigation and Corrective Action Our next interim report is scheduled for July 15, 1979. f I Submitted by: ~ @__ b w
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Approved by: 4 MON . dU Concurrence by: -/, -
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