ML20093L236
| ML20093L236 | |
| Person / Time | |
|---|---|
| Site: | Midland |
| Issue date: | 06/27/1984 |
| From: | Mooney J CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Harrison J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| CSC-7950, NUDOCS 8407310335 | |
| Download: ML20093L236 (4) | |
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General Offices: 1946 West Pernall Road, Jackson, MI 49201 + (517) 788-0774 i
/ PRItJCIPA1. STAFF g RA l ' CORP
[&ll June 27, 1984
)/RA DRS RC DRSS Mr J J Harrison, Chief
'9A0 ML Midland Project Section SGA OL U S Nuclear Regulatory Commission EIC OI i.
799 Roosevelt Road ORMA FILE W Glen Ellyn, IL 60137 MIDLAND ENERGY CENTER MIDLAND DOCKET NOS 50-329, 50-330 LOAD TEST FOR 1 AND 1A SERVICE WATER PUMP SYSTEM FILE 0485.16 SERIAL CSC-7950 Notes of 6/25/84 telecon between NRR Region III to discuss Service Water Pump Structure (SWPS) Plate Load Test.
Participants R. Landsman, Region III J. Mooney*
K. Razdan D. Sibbald R. Wheeler
(*Part time)
PURPOSE The purpose of this telecon was to discuss NRC's comments on CPCo submittal for SWPS Plate Load Test (JAMooney letter to JJHarrison, Serial CSC-7886 dated June 13, 1984).
SUMMARY
The following is a summary of NRC's comments and CPCo's responses which were concurred to by R. Landsman.
NRC'S COMMENT #1 After the seating loads, for the first few load increments, the load should be held for sufficient time so that settlement vs log time plot flattens out.
Sufficient settlement readings shall be taken to acccmplish this.
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2 CPCO' RESPONSE' e
Agreed.
NRC'S COMMENT #2 To reduce the effect of confinement, the size of the plate s'hould be reduced from 30" to 21".
CPCO RESPONSE CPCo indicated that per ASTM 1196, Sec 4.2,_the size of the pit is required to be 4 tires the diameter of the plate to eliminate any affect of confinement.
However CPCo agreed to change the diameter of the plate to 21" to perform the test.-
NRC'S COMMENT #3 I-The settlement readings should be made relative to the nearest deep seated bench marks (DSB) instead of using the SWPS as a reference mark.
CPCO RESPONSE Agreed.
NRC'S COMMENT #4 A sample of the soil below the plate should be saved in a jar.
CPCO RESPONSE Agreed to preserve a soil sample after the load test is performed.
NRC'S COMMENT #5 The plate should be leveled to a tolerance of 1/16" instead of 1/8".
A very thin layer of fine sand should be sprinkled before placing the plate.
CPC0 RESPONSE Agreed.
NRC'S COMMENT #6 The readings in the dial gauges should be taken to an accuracy better than !
50 psi.
CPCO RESPONSE The readings will be taken to an accuracy of 1 25 psi by interpolation.
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CPCo also stated that since the size of plate is smaller, they may change the load increment to 5% or~10% of the estimated ultimate design strength instead of the 3.3% as stated in the June 13, 1984 CPCo letter.
NRC'S COMMENT-#7 A copy of Drawing C-2039 should be provided to J. Kane.
CPCO RESPONSE CPCo has provided the drawing to J. Kane.
NRC'S COMMENT #8 With respect to Note C-1 Drawing C-2036-4, the dead load of the plate, jacks etc. should be accounted for in the final report.
'CPC0 RESPONSE CPCo agreed.
NRC'S COMMENT #9 The maximum load to which the plate is loaded before starting the decrements should be changed to correspond to 130% of the maximum predicted net design bearing pressure.
CPCO RESPONSE CPCo agreed to revise the loading to 130% of the net maximum design bearing pressure. The maximum bearing, approx 15 k.s.f., occurs for the seismic condition.
NRC'S COMMENT #10 The jack calibration should be included in the load test report.
CPCO RESPONSE CPCo agreed.
NRC'S COMMENT #11 The measured settlements of the plate, during the load test should be compared to predicted settlements based on the modulus used in the design.
CPC0 RESPONSE CPCo indicated that before the test, they will have available a set of plots of E vs settlements for various bearing pressures.
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4 NRC'S COMMENT #12 It seems that,the constant-K = 0.95 from NAVDOC DM-7, is missing from the a.
equation stated in the letter, b.
What value of p will be used?
c.
The "E" should be calculated for calculated design bearing pressure.
CPC0 RESPONSE 0.95 a.
CPCo stated that the constant should be X 4 = 1.21, and agreed to modify.the formula ~in t:te letter by this factor.
.b.
CPCo stated that a p=0.5, which is the value for undrained condition, will be used.
c.
'CPCo indicated that as stated in the June 13 letter, E will be calculated for the design net bearing pressure under service loads.
(Not loads including seismic since "E" value for seismic condition is determined by the shear wave velocity).
NRC'S COMMENT #13 With reference to Drawing C-2036-2, it seems that there is some friction between the lateral bracing and the sides of the excavation pit.
CPC0 RESPONSE The jacks are located at the bottom of the strut, therefore all the load is transferred to the plate.
.NRC'S COMMENT #14 R. Landsman should be provided a set of data sheets, which will be used to record the test results, before the test is started.
CPCO RESPONSE CPCo agreed.
bD JAM /KBR/klw CC Administrator, Region III DSHood, NRR Project Manager, Washington Midland Project Manager, Region III Midland Resident Inspector, Midland OC0684-0005A-CN01