ML18043A746
| ML18043A746 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 06/19/1979 |
| From: | Hoffman D CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Ziemann D Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7906220190 | |
| Download: ML18043A746 (7) | |
Text
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consumers Power company General Offices: 212 West Michigan Avenue, Jackson, Michigan 49201
- Area Code 617 788-0660 June 19, 1979 Director, Nuclear Reactor Regulation Att Mr Dennis L Ziemann, Chief Operating Reactors Branch No 2 US Nuclear Regulatory Commission Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT -
INFORMATION REQUESTED ON PWR FEEDWATER LINES Consumers Power Company's response to your letter dated May 25, 1979 concern-ing c*racking in feedwater lines at D C Cook Units i and 2 is provided belcw.
Due to the extremely short period of time allowed to assemble these responses, some remain inco'mplete.
The incomplete i terns will be further addressed prior
- to July 30, 1979.
DESIGN' Item 1 Provide as-built piping or isometric drawings of the feedwater line to-steam generator *Sparger.within containment.
Show details of the design such as dimensions, pipe schedule, support _type and locations, pipe restraints, and valve( s). *
Response
One copy of each of the followi!1g d,rawings has* 'heen provided to the NRC Staff:
A.. Isometric of the feedwater line, inside containment, Drawing EE-9-18, Sheet 1 of 2.
B.
Equipment drawings delineating the feedwater line to steam generator spar-ger connect.ion, Drawings E-232-971 'and E-232-959.
C.
Hange_r location drawings (inside containment), Drawings M-151 and M-153.
D.
Hanger sketches for the feedwater hangers located inside containment.* Note:
These sketches reflect the "as designed" hanger and do not reflect fiel~
- changes/modifications.
Source:
Bergen Pc.tter,;on Drawings 391-2 through 402-1, inclusive.
. i
- E.
Pipe schedule:
18" Schedule 60, except for the spool piece passing through the containment penetration which is Schedule 80.
(Source:
Palisades Piping Class Summary M-259).
F.
Valves:
There are no valves on the feedwater lines inside containment.
Item 2 2
Provide the results of any stress or fatigue analyses which was performed for this system.
Response
Consumers Power Company is in' the process of attempting to retrieve the results of stress/fatigue analyses performed for this system.
This information will be submitted to you prior to July 30, 1979.
FABRICATION HISTORY Item 1 Supply a list of the materials for the steam generator sparger, steam generator feedwater nozzles and feedwater piping within containment.
Response
Materials used are as follows:
A.
Feedwater Piping:
A-106 Grade B B.
Nozzle Safe End:'
SA-508 Cl 1 C.
Nozzle Forging:
SA-508 Cl 2 D.
Sparger & Sparger Sleeve:
A-106 Grade B Item 2 Provide the details of the welding process(es) used to make the nozzle-to-pipe, pipe to sparger and piping welds.
Include details of welding such as preheat, joint configuration (include with or without backing ring), and post weld treat-ment, if any.
Response
Welding details are as follows (missing information will be submitted pior to July 30' 1979) :
A.
Pipe to Pipe:
(Shop. Weld)
TIG root pass followed by shielded metal arc or shielded metal arc plus subarc.
Midwest Pipe Procedures:
CS-12-A and CS-16-A, both Revision 3.
B.
Pipe-to-Pipe:
To be supplied.
(Field Weld)
C.
Pipe-to-Nozzle Safe End:
To be supp+ied.
D.
Safe End-to-Nozzle:
CE Welding Procedure WC-2966B-959.
E.
Nozzle-to-Sparger:
There is no pipe-to-sparger weld, per se.
Preheat The sparger is bolted and fillet welded to a sleeve in the feedwater nozzle.
The slee~e is not welded to the nozzle.
Details of this fillet weld are not currently available.
See CE Drawing E-232-971.
A.
Pipe-to-Pipe:
None specified.
(Shop Weld)
B.
Pipe-to-Pipe:
To be supplied.
( Ffeld Weld)
C.
Pipe-to-Nozzle Safe End:
To be supplied.
D.
Safe End-to-Nozzle:
To be* supplied.
E.
Pipe-to-Sparger:
No weld exists.
Post Weld Heat Treatment A.
Pipe-to-Pipe:
(Shop Weld)
B.
Pipe-to-Pipe:
(Field Weld) 1175 +/- 75°F, hold one hour per inch of thickness.
(Per Welding Procedure~ CS-12-A and CS-16-A.)
To be supplied.
C.
Pipe-to-Safe End:
To be supplied.
D.
Safe End-to-Nozzle:
To be supplied.
E.
Pipe-to-Sparger:
No weld exists.
Joint Configuration A.
Pipe-to-Pipe:
See Ske.tch 67-273-A.
Note:
Backing rings not used.
(Shop Weld)
B.
Pipe-to-Pipe:
(Field Weld)
See Bechtel Drawing 5935-M~240, Sheet 3 of 6 for Piping Class "EB. II Note:. Backing: rings not used.
C.
Pipe-to-Safe End:
To be supplied.
3
D.
Safe End-to-Nozzle:
See CE Drawing E-232-971.
Note:
Backing rings not used.
E.
Pipe-to-Sparger:
No weld exists.
Item 3 4
Provide the NDE performed during and after fabrication of the weld joints re-quested in question 2.
Response
The following NDE was performed:
A.
Pipe-to-Pipe:
(Shop Weld)
Post weld RT of all butt welds (based on Midwest Spool Piece Sketches 17 and 18 (Order 67-273-0001) and Sketches l through 12, inclusive (Order 67-273-0002)).
B.
Pipe-to-Pipe:* To be supplied.
(Field Weld)
C.
Pipe-to-Safe End:
To be supplied.
D.
Safe End-to-Nozzle:
Post weld MT and RT based on CE Drawing E-232-959.
E.
Pipe-to-Sparger:
No weld exists.
Item 4 Provide the Code edition to which the feedwater piping system was fabricated.
Response
This information is not readily available from the vendor.
We believe that it was either the 1955 or 1967 USAS B31.l code.
We will attempt.to clarify this by July 30, 1979.
Item 5 State the fracture toughness requirements, if any, for the feedwater piping system.
Response
There are no fracture toughness requirements for the feedwater piping system.
PRESERVICE/INSERVICE INSPECTION AND OPERATING HISTORY Item l State whether the feedwater system welds received a preservice inspec.tion in accordance with ASME B&PV Code,Section XI.
5
Response
The feedwater piping system was not subject to a PSI.
Item 2 Provide the extent of inservice inspection performed on the feedwater pipe to steam generator nozzle welds.
Include the results of the examinations, any corrective actions taken and causes of any failures.
Response
There has been no ISI performed on the feedwater piping system within contain-ment.
However, ISI has been conducted on the high energy piping welds of the feedwater system outside containment and on five other pipe-to-pipe or*
pipe-to-valve welds outside containment.
One weld (FWS-18-FWL-181-244) was examined with RT and did not meet the acceptance criteria of NB-5320 and was repaired in 1973.
The defect noted on RT was fabrication defect (4" of nonfus-ion).
The repair weld was RT examined subsequent to repair and was found to be acceptable.
Item 3 Provide the schedule and extent of inservice inspection for the feedwater system for the next inspection interval.
Response
The following ISI is scheduled to be performed during the remainder of this interval:
A.
Eight high energy welds (outside containment) are to be volumetrically examined twice.
B.
Five hangers (inside containment).
C.
Four pipe lugs (inside containment).
D.
One elbow-to-pipe weld (inside containment).
The following ISI is scheduled to perform during the next ISI Interval:
A.
Eight high energy welds (outside containment) are to be examined once each.
B.
Two piping welds (inside containment).
C.
Six hangers (inside containment).
D.
Four pipe lugs (inside containment).
Item 4 Provide any history of water hammer or vibration in the feedwater system and design changes and/or actions taken to prevent these occurrences.
Response
6 Palisades has not experienced any water hammer or vibration in the feedwater sys-tem.
CP Co letters to the NRC_dated July 16, 1975, January 24, 1978 and August 9, 1978 describe design changes and actions taken by CP Co to prevent these occurrences.
Item 5 Provide a description of feedwater chemistry controls and a summary of chemistry data.
Response
During normal power operation at Palisades, the -following* feedwater 'chemistry control limits are adminstratively imposed:
pH Cation Conductivity Dissolved Oxygen Iron Copper Normal 8.8-9.2 0.5 µmho/cm 0.010 ppm 0.01 ppm 0.01 ppm Abnormal 8..5-9. 3 1.5 µmho/cm 0.015 ppm 0.03 ppm Continuous monitoring is provided for pH, cation conductivity, and dissolved oxygen.
Daily grab samples are taken for conductivity, morpholine, ammonia, hydrazine, iron, copper and sodium.
A weekly determination of feedwater silica is also made.
Control of feedwater chemistry is accomplished by additions of hydrazine and morpholine.
A powdered resin condensate polishing system has been recently in-stalled.
Feedwater heaters are laid up either wet or dry depending on length of shutdown.
Layup specifications are as follows:
Wet 9.0-10.0 50 +/- 25 ppm 80%
~- '"
-~*...
7 Finally, Consumers Power Company would like to note that the following signi-ficant differences exist between Cook and Palisades Plant feedwater piping:
(1) Palisades used no backing rings in the pipe-to-nozzle safe end weld, and (2) the size mismatch between pipe and nqzzle at Cook is approximately two inches; whereas for Palisades, it is only 0.125 - 0.1875" OD and o.4375 _
0.500" ID.
David P Hoffman Assistant Nuclear Licensing Administrator CC:
JGKeppler, USNRC