ML20040C952
| ML20040C952 | |
| Person / Time | |
|---|---|
| Site: | Midland |
| Issue date: | 01/25/1982 |
| From: | Mooney J CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20040C953 | List: |
| References | |
| 15493, NUDOCS 8201290404 | |
| Download: ML20040C952 (3) | |
Text
.
d' Consumers Power i Pr siJ
- Projects, Engineering and Construction General offices: 1945 West Parnell Road, Jackson, MI 49201 + (517) 788 0453 January 25, 1982 9L Q g
RECEIVED 3
JAN 281982> 12 Harold R Denton, Director 9,
p a ng Office of Nuclear Reactor Regulation ty.u x tur.inm u j
US Nuclear Regulatory Commission g
Washington, DC 20555 g
O w
MIDLAND PROJECT MIDLAND DOCKET NOS 50-329, 50-330 EVALUATION REPORT FOR ThE FEEDWATER ISOLATION VALVE PITS FILE 0485.16 SERIAL 15493 ENCLOSURES:
(1) EVA,LUATION fW FEEDWATER ISOLATION VALVE PITS AT MIDLAND PLANT (2) FEEDWATER ISOLATION VALVE PIT CRACK MONITORING PROGRAM On December 10, 1981 and January 11, 1982, meetings were held with the Staff and its consultants to discuss concrete cracks in the auxiliary building, the service water pump structure, the diesel generator buildings and the feedwater isolation valve pits. During the January 11, 1982 meeting, Consumers Power agreed to provide the NRC with an evaluation of the significance of concrete cracks relative to the design strength of the feedwater isolation valve pit structures.
In response to this commitment, we are providing the enclosed report (Enclosure 1) entitled " Evaluation of Feedwater Isolation Valve Pits at Midland Plant" by Messrs W G Corley and A E Fiorato of Construction Technology Laboratories, a Division of the Portland Cement Association. This report presents an evaluation of the significance of cracks observed in the feedwater isolation valve pit structures. The information, measurements and test data presented in Enclosure 1 lends further suppcrt to our conclusion that:
(1) cracks in an adequately reinforced concrete member do not prevent the merber from developing its expected strength, and (2) cracks in the feedwater isolation pits are the result of restrained volumetric changes which occurred during the curing and drying of concrete and are not due to structural j
distress.
In addition, a program for monitoring structural integrity durita O8 the implementation of remedial measures is outlined.
,5 During the underpinning operation, cracks in the feedwater isolation valve f [
pits will be monitored and recorded by mapping at the time of specific construction milestones. These construction milestones, at which time crack mapping will.be performed, are identified in Enclosure 2.
The frequency of oc0182-0013a100 8201290404 820125 PDRADOCK05000g A
7 2
crack monitoring identified f u this enclosure is based upon our discussions with the Staff and its consultants during the recent January 19, 1982 audit held in Ann Arbor, and this crack monitoring program incorperates the Staff's Concerns.
Based upon the information contained in Enclosure 1, we conclude that the present cracks in the feedwater isolation valve pit structures are of no structural significance, and any changes in their condition during the underpinning operations will be monitored and, if necessary, evaluated.
%\\oD Mooney Executive Manager Midland Project Office For J W Cook JWC/RLT/dsb
(
CC Atomic Safety and Licensing Appeal Board, w/o CBechhoefer, ASLB, w/o MMCherry, Esq, w/o FPCowan, ASLB, w/2 RJCook, Midland Resident Inspector, w/o RSDecker, ASLE, w/o SGadler, w/o -
JHarbour, ASLB, w/o GHarstead, Harstead Engineering, w/a DSHood, NRC, w/a (2)
DFJudd, B&W, w/o JDKane, NRC, w/a FJKelley, Esq, w/o RBLandsman, NRC Region III, w/a WHMarshall, Esq, w/o JPMatra, Naval Surface Weapons Center, w/a W0tto, Army Corps of Engineers, w/a WDPaton, Esq, w/o SJPoulos, Geotechnical Engineering, w/a FRinaldi, NRC, w/a HSingh, Army Corps of Engineers, w/a AStamiris, w/o i
l' oc0182-0013a100
1
-ETCLOSURE 2__
FEEDWATER ISOLATION VALVE PIT CRACK MONITORING PROGRAM During the underpinning operation, crt2cks in the feedvater isolation valve pit' structures will be monitored by mapping at the time of the following construction milestones:
1.
Prior to extending the access shaft belov Elevation 609.' for the purpose of taking baseline measurements.
2.
During the tunneling to Pier W 9 (ie, Pier N on Figure 8 of Enclosure 1.)
J 3.
After completion of tunneling to Pier W 9 I
h.
After completion of all excavation.under the feedvater isolation valve pits.
5 At two-month maximum intervals after completion of the excavation under the feedvater isolation valve pits, or at increased intervals if settlement becomes significant.
6.
Prior to jacking of the permanent underpinning.
T.
After jacking of the permanent underpinning.
8.
After any rejacking of the temporary support system.
i
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