ML19338D306
| ML19338D306 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 09/12/1980 |
| From: | Janecek R COMMONWEALTH EDISON CO. |
| To: | Oconnor P Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8009220293 | |
| Download: ML19338D306 (4) | |
Text
- .
+.
,r3 mm
) One First National Plaza, Chictgo, lifinois O
O Addrtss Riply to: Post Office Box 767 Chicago. Illinois 60690 September 12, 1980 Mr. Paul-W. O'Connor, Project Mgr.
Operating Reactors Branch 5 Division of Licensing U.S. Nuclear Regulatory Commission Washington, DC 20555
Subject:
Dresden Station Unit 1 Chemical Cleaning Solidification Test Results NRC Docket No. 50-10
Dear Mr. O'Connor:
Enclose for your use is information pertaining to the July 9 and 10, 1.'
field demonstration of the Dresden 1 chemical cleaning solidif ation system.
Attachment "A" outlines the corrosion test 1
, ult s fo r t=0, t)30 days, and t 360 days sampling intervals.
Also enclosed, in Attachment "B",
are the results of a laboratory corrosion rate study which is being performed.
These results were previously discussed with NRC staff personnel at Dresden on August 14, 1980.
Please address any questions concerning this matter to this office.
One (1) signed original and thirty-nine (39) copies of this transmittal are provided for your use.
Very truly yours, Robert F. Janecek Nuclear Licensing Administrator Boiling Water Reactors
-800922-0273
/0 6696A
1 ANALYSIS OF 30 & 60 DAY CORROSION TEST RESULTS (Ref:
Test Procedures f or NS-1 Solidified Waste; handout prepared for the NRC, dated July 9, 1980)
The purpose of this test was to determine the corrosion rate of a barrgl containing a solidified simulated radwaste produced using actual procedures, equipment and personnel at the Dresden Station Chemical Cleaning Facility.
The t h 30 & 60 day results clearly indicate that the samples are well within the 50% minimum wall thickness criteria set by the NRC.
However, it must be stressed that these numbers reflect attempts to make a field demonstration into a " controlled experiment."
It would be technically unjustifiable and scientifically unsound, to attempt to extrapolate " meaningful data," f rom the results of this one barrel and apply it to the barrels which will be generated as a result of the chemical cleaning.
l The extrapolation of these data may not necessarily yield revelant long term corrosion rates due to many uncontrollable variables.
These variables include tolerances of barrel and paint thickness, distortion due to sample removal, and non-linearity in corrision rates.
As a result, the precision and accuracy of this field test may have affected the reliability of the data (i.e. the sample measurements).
This prevents us from attaching significant importance to the corrosion rates in
" Attachment A".
To provide more meaningful data, additional laboratory investigations were initiated.
This program consisted of placing metal barrel coupons in samples of simulated NS-1 radwaste which had been solidified by the DOW process.
These coupons were obtained from 00T 17H carbon steel drums which are representative of the actual barrels which will. be used to hold the chemical cleaning radwaste.
Both sides of the coupon were in contact with the solidified NS-1.
Corrosion rates for these specimens were determined on a weight loss basis.
A correction f actor was applied to account for the external paint film being removed from the samples during removal f rom the solidfied blocks.
The 39 and 229 day results are presented in " Attachment B."
These data show very little corrosion occurs between the solid matrix and the barrel.
These low rates indicate insignificant corrosion can be expected f or an extended storagG period.
It is important to distinguish the basic difference between the two attachments.
Although the results presented in = " Attachment A" are within the NRC imposed guidelines, the data were derived from a field demonstration.
" Attachment B" on the other hand, reflects the results of a more precise laboratory investigation.
IML:mnh/6492A Attachments 9/10/80
8 a
" Attachment A" Corrosion Test Results Coupon #
Identification Code Wall Thickness (inches)
% Corrosion
- 4 Mean Point 1 Point 2 Value 1
00 Tp 1
.0475
.0485
.04800 2
00 Tp 2
.0470
.0480
.04750 3
00 Cr 1
.0440
.0460
.04500 4
00 Cr 2
.0440
.0450
.04450 5
00 Bm 1
.0450
.0450
.04500 6
00 Bm 2
.0445
.0465
.04550 7
30 Tp 1
.0470
.0480
.04750
- 1. 04%
8 30 Tp 2
.0465
.0470
.04675 1.58%
9 30 Cr 1
.0435
.0440
.04375 2.77 %
10 30 Cr 2
.0435
.0440
.04375 1.69%
11 30 Bm 1
.0440
.0440
.04400 2.22%
12 30 Bm 2
.0445
.0445
.04500 1.10%
13 60 Tp 1
.0465
.0470
.04675 2.60%
14 60 Tp 2
.0460
.0470
.04650 2.10%
15 60 Cr 1
.0430
.0440
.04350 3.33%
16 60 Cr 2
.0430
.0440
.04350 2.25%
17 60 Bm 1
.0435
.0445
.04400 2.22%
18 60 Bm 2
.0440
.0445
.04425 2.75%
19 90 Tp 1
20 90 Tp 2
21 90 Cr 1
22 90 Cr 2
23 90 Bm 1
24 90 Bm 2
- % Corrosion Determined Using the Following Equation:
\\
Control Samp1E\\
Samp 3kah6 Tent Measurements j
- at
)x100=%Cctrosion
(
or Tt90
\\ontrolSample'I rC Measurements j 6480A
I "ATTACll11ENT B"
~
BARREL METAL SURVEILLANCE SAMPLES DOT Drum Samples Solidified in Spent NS-1 (4 pucks - 2 drum Sample / Puck)
Drum Samples - Drum DOT 17H Carbon Steel - External Painted Solvent NS-1 -- 1050 PPM Fe 600 PPM Ni Net Wt. Solvent 3,956 g Boiled Down to 560 g (Factor of 7)
Corrected After Placed Removed Sample Contact Size Painted Weight Tes ting In From Days No.
(Immersed 3.9" total)
Wt.g.
(No Patnt)
Wt.
Metal Loss, n.
Test Test Tested 1
1 15/16" 11.084 11.027 11.0119 0.0161 (0.137%) 10/5/79 11/13/79 39 2
2 3/16" 11.780 11.719 11.7031 0.0159 (0.136%) 10/5/79 11/13/79 39 3
1 15/16" 11.316 11.258 11.249 0.0090 (0.080%) 10/5/79 5/22/80 229 4
2 3/16" 11.3389 11.2805 11.269 0.0115 (0.102%) 10/5/79 5/22/80 229
.