ML19261B232
| ML19261B232 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 12/06/1978 |
| From: | Webb Patricia Walker GENERAL ELECTRIC CO. |
| To: | |
| Shared Package | |
| ML19261B218 | List: |
| References | |
| 509-ATR-17, NUDOCS 7902140271 | |
| Download: ML19261B232 (7) | |
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509.ATR-17 EWA EAC22-05 DRF 509DEV0021 APPARENT TEST RESULTS DRESDEN 1 RADIATION LEVEL REDUCTION PROGRAM EVAL'.ATION OF LONG TERM TESTS OF SIMULATED CLAD-CRACKED SPECIMENS BY W. L. WALKER Verified by:
6b M
E. G. Brush, Senior Engineer Plant Materials & Process Development Approved by:
L 6 L' G '
R. L. Cowan, Manager Plant Materials & Process Development This memorandum is an internal, informal document issued for the primary purpose of disseminatin; current working information and data relating to Plant Materials Engineering.
This memorandum records technical information status at the date of publication and may not represent final disposition or conclusions related to the reported study.
Changes in test data, analytic models, and evaluations subsequent to publication of this document may supercede the reported work, and verification of applicability should be made before these result-are used in final design work.
DISTRIBUTION L. D. Anstine MC V04 R. L. Cowan MC 407 J. S. Gay MC 888 G. M. Gordon MC 138 J. C. LeMaire MC 138 R. A. Proebstle MC 148 C. P. Ruiz MC V04 D. E. Wax MC V04 M. T. Wang MC 407 PoANort\\
t DISCLAIMER OF RESP 0flSIBILITY This document was prepared by the General Electric Company pusuant to a contract with the Commonwealth Edison Company.
Except as otherwise provided in such contract, neither the General Electric Company nor any of the contributors to this document nor any of the sponsors of the work makes any warranty or representation (express or implied) with respect to the accuracy, completeness, or usefulness of the information contained in this document or that the use of such information may not infringe privately owned rights; nor do they assume any responsibility for liability of damage of any kind which may result from the use of any of the information cnntained in this document.
509.ATR-17 5
As a part of the corrosion test program associated with the chemical cleaning of the Dresden I primary system, simulated through-clad cracked 1-T WOT fracture mechanics specimens with plain carbon and low alloy steel base materials were exposed to the proposed solvent (Dow NS-1) and then to a simulated BWR environment (0.2 ppm 0 ) for approximately four weeks.
The results of 2
these tests have been reported in previous PME Transmittals (References 1,2, 3).
No indications of a significant deleterious effect of exposure to the solvent on crack propegation were observed in the four-week exposures.
While the exposure time was sufficient for the complete themal decomposition of any residual solvent, and the observance of any relatively short term effects of the solvent or its decomposition products, it was considered desireable to accumulate as much exposure time as was practical within the limits of the required dates for the Commonwealth Edison licensing submittal. An additional exposure of 2592 hours0.03 days <br />0.72 hours <br />0.00429 weeks <br />9.86256e-4 months <br /> in the simulated BWR environment has been accumulated on specimens from each heat of oaterial initially tested, and the preliminary results of non-destructive and destructive examinations are reported here.
The available autoclave space did not pemit the continued testing of all of the specimens exposed in the four-week exposure.
Single control specimens and specimens which had been exposed to NS-1 were selected from each heat of material from among the group loaded to 90 ksi Nin.
In addition, duplicate control and NS-1 specimens were selected from thosh materials which had exhibited any indications of significant crack propagation in the four-week tests, to the limit of the capacity of the autoclave.
Each specimen was polished on one side notch to delineate the existing crack after the four-week exposure, and the crack length at that time was determined photographically.
All specimens were examined after an additional 1274 hours0.0147 days <br />0.354 hours <br />0.00211 weeks <br />4.84757e-4 months <br /> exposure, and
509. AT R-17.
again af ter an additional 1318 hours0.0153 days <br />0.366 hours <br />0.00218 weeks <br />5.01499e-4 months <br /> exposure.
The minimum total exposure seen by any specimen was 3239 hours0.0375 days <br />0.9 hours <br />0.00536 weeks <br />0.00123 months <br />, and the maximum was 3380 hours0.0391 days <br />0.939 hours <br />0.00559 weeks <br />0.00129 months <br />. This variance in total exposure is the result of slightly dif ferent exposures during the initial nominal four-week exposure.
The specimens tested and the results of non-destructive photographic measurements of crack lengths are shown in Table 1.
Following the non-destructive measurement of apparent crack extension, all specimens were sectioned through the mid-plane and metallographic measurements of crack lengths were made.
The results of these measurenents are also shown in Table 1.
True crack extension was observed in 13 of the 43 specimens tested. Cracking occured in 7 control specimens which had only seen demineralized water at all stages of the exposures, and in 6 specimens which had been exposed to a simulated cleaning cycle in Dow NS-1 solvent.
The magnitudes of the crack extensions were not greatly different between the two groups. These results are consistent with those obtained in the short term 4-week exposures, and they indicate that the risk of cracking associated with exposure to NS-1 is not greatly different from that associated with exposure to dimineralized water.
The general effect of exposure of simulated clad-cracked specimens to NS-1 is some general galvanic corrosion of the base metal in the immediate vicinity of the crack, and blunting of the crack tip.
On those specimens which exhibited a significant increase in depth of penetration, but no metal-lographic indications of crack extension, the increase in depth was due to general corrosion of the original fatigue pre-crack crack tip.
539.ATR-17 REFERENCES 1.
W.L. Walker, Fracture Mechanics Tests of Simulated Clad Cracks in ASTM A336 Gr. F1 Exposed to NS-1 Cleaning Solvent, PME Transmittal No. 77-509-70, August 8, 1978 2.
W.L. Walker, Fracture Mechanics Tests of Simulated Clad Cracks in ASTM A335-P1, A302-B, and A105 Exposed to Dow NS-1 Cleaning Solvent, PME Trans-mittal No. 78-509-002, January 5,1978 3.
W.L. Walker, Fracture Mechanics Tests of Simulated Clad Cracks in Additional Heats of ASTM A335-P1, A302-B, A106-B, and A105 Exposed to Dow NS-1 Cleaning Solvent, PME Transmittal No. 78-509-66, April 28, 1978
509.ATR-17 TABLE I Penetration Depth (I.ches)(I)
Metallographic Alloy Heat No.
Specimen Start Finish Measurement A336-F1 210832 Controi(2) 0.1 57 0.153 0.163 NS-1(3) 0.229 0.693 0.557(4)
I4) 43563 Control 0.174 0.1 68 0.172 NS-1 0.164 0.179 0.170 45716 Control 0.161 0.158 0.153 NS-1 0.149 0.148 0.150 A335-P1 3263 Control 0.095 0.124 0.379(4)
I4) 0.098 0.094 0.252 NS-1 0.134 0.311 0.198 0.107 0.356 0.453(4) 3582 Control 0.171 0.172 0.439(4) 0.172 0.182 0.306(4)
NS-1 0.154 0.182 0.176 0.200 0.218 0.221 814950 Control 0.209 0.209 0.214 0.153 0.151 0.165 NS-1 0.157 0.208 0.200 0.178 0.244 0.230 A302-B 2529 Control 0.095 0.088 0.071 NS-1 0.093 0.123 0.110 5923 Control 0.145 0.137 0.141 NS-1 0.155 0.201 0.185 5933 Control 0.157 0.159 0.142 NS-1 0.176 0.194 0.181 A106-B 66549 Control 0.13b 0.089 0.178(4) 0.120(5) 0.081 0.072 NS-1 0.1 03 0.124 0.098 0.153(5) 0.072 0.056 66402 Control 0.167 0.160 0.160 0.152 0.152 0.156 NS-1 0.144 0.175 0.162
509.ATR-17 TABLE I - continued Penetration Depth (Inches)(I)
Metallographic
~
Alloy Heat No.
Specimen Start Finish Measurement A105 33875 Control 0.099 0.091 0.081 0.097 0.108 0.087(4)
NS-1 0.111 0.103 0.097 0.102 0.105 0.087 44331 Control 0.164 0.158 0.167 0.153 0.153 0.153 NS-1 0.136 0.160 0.166(4) 0.149 0.144 0.155I4) 2748 Control 0.167 0.163 0.164 0.155 0.158 0.165 NS-1 0.149 0.175 0.176(4)
I4) 0.1 51 0.179 0.E00 NOTES:
1.
" Start" is depth of fatigue pre-crack; " Finish" is final depth of cenetration, including both general corrosion and any crack propagation.
Measurements made non-destructively on specimen side groove.
0 2.
100 hrs. in 250 F denineralized water prior to BWR exposure 3.
100 hrs. in 250 F "used" NS-1 prior to BWR exposure 4.
Crack extension observed metallographically 5.
These initial measurements appear to have been seriously in error.