ML20214N093
| ML20214N093 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 11/14/1986 |
| From: | Haynes J ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| To: | Kirsch D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| REF-PT21-86-388-000 ANPP-39080-JGH, DER-86-01, DER-86-1, IEIN-85-033, IEIN-85-33, PT21-86-388, PT21-86-388-000, NUDOCS 8612030535 | |
| Download: ML20214N093 (10) | |
Text
m D./
q, Arizona Nuclear Power Project
/f P O. BOX 52034 e PHOENIX, ARIZONA 85072-2034
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November 14, 1986 ANPP-39080-JGH/DJW/DRL-92.1I,b U. S. Nuclear Regulatory Commission Region V 1450 Maria Lane - Suite 210 Walnut Creek, California 94596-5368 Attention:
Mr. D. F. Kirsch, Director Division of Reactor Safety and Projects Palo Verde Nuclear Generating Station (PVNGS)
Units 1, 2, 3 Docket Nos. 50-528, 529, 530
Subject:
Final Report - DER 86-01 A 50.55(c) and 10CFR21 Condition Relating to Nozzle-to-Shell Welds on ASME III Tanks and Heat Exchangers File: 86-006-216; D.4.33.2
Reference:
(A) NRC IE Information Notice 85-33 dated April 22, 1985
Dear Sir:
Attached, is our final written report of the Deficiency under 10CFR50.55(e) referenced above. The 10CFR21 evaluation is also included.
Very truly yours,
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J. G. Haynes Vice President Nuclear Production JGH/DRL:kp L>
Attachments cc: See Page 2 7-
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861203053S 861114 PDR ADOCK 0500 8
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s-DER 86 Final Report Mr. D. F. Kirsch Acting Director Page Two November 14, 1986 ANPP-39080-JGH/DJW/DRL-92.11 cc:
J. M. Taylor Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D. C.
20555 A. C. Gehr (4141)
R. P. Zimmerman (6295)
Records Center Institute of Nuclear Power Operations 1100 circle 75 Parkway - Suite 1500 Atlanta, Georgia 30339
i-FINAL REPORT - DER 86-01 DEFICIENCY EVALUATION 50.55(e)
ARIZONA NUCLEAR POWER PROJECT (ANPP)
PVNGS UNITS 1, 2, 3 I.
Description of Deficiency IE Information Notice 85-33 addresses undersized nozzle-to-shell welded joints. in tanks and heat exchangers constructed under the ASME boiler and pressure vessel codes. In order to address the bulletin's concerns, Bechtel Construction instituted a Special Construction Inspection Plan (SCIP 676.0) to inspect some of the nozzle-to-shell welds on selected ASME Section III tanks and heat exchangers in Unit 3.
The inspection was to be conducted on.one (1) vessel per manufacturer and the selected nozzles were to be inspected for compliance to the applicable vendor drawings and ASME code requirements. A representative sample of nozzles for each vessel was inspected using the following generic criteria: one (1) of each size nozzle was inspected or if there was an abundance of one (1) size nozzle, that nozzle size was the largest number of those nozzles inspected (for a total of four (4) or five (5) nozzles per vessel). The vendor drawings were checked to verify that the vessel design complied with the ASME code. If the drawings met the ASME code requirements, a representative sample of nozzles for each vessel was inspected using the following criteria:
A total of 5 nozzles (maximum).
Include aanway cover whenever possible.
Include one of each size nozzle.
If there are more than one nozzle of a given size, inspect one or more of that size nozzle, provided the total number of nozzles inspected per tank does not exceed 5.
Tag No.
Description Supplier / Manufacturer SIE-X03 Spray Chemical Storage Tank C-E/ Process Equipment Co.
CHN-E02 Letdown Heat Exchanger C-E/ Richmond Engineering Co.
CHE-E01 Regenerative Heat Exchanger C-E/Ametek EWA-E01 Ess. Cool. Water heat Struthers Wells Corp.
Exchanger CHN-X01 Volume Control Tank C-E/CTI Nuclear, Inc.
EWB-T01 Ess. Cool. Water Surge Tank PX Engineering Co.
CHN-D02 Deborating Ion Exchanger C-E/CTI Nuclear, Inc.
SIA-E01 Shutdown Heat Exchanger C-E/ Engineering & Fabricators Co.
DFB-T02 Diesel Fuel Oil Day Tank Cooper Energy Services The nozzle-to-shell welds on the following vessels were found to be
- acceptable and in accordance with the vendor ' drawings:
- 1) The ess cool. water surge tank (EWB-T01)
- 2) The ess. cool water heat exchanger (EWA-E01)
- 3) The regenerative heat exchanger (CHE-E01)
The nozzle-to-shell welds on the following vessels were found not to comply with their respective vendor drawings, and NCR's were issued to
. document the nonconforming ~ condition:
Tag No.
Description NCR No.
DFB-T02 Diesel Fuel Oil Day Tank MG-2900 CHN-D02 Deborating Ion Exchanger NA-1814 SIA-E01 Shutdown Heat Exchanger NA-1816 CHN-E02 Letdown Heat Exchanger NA-1793-SIE-X03 Spray Chemical Storage Tank NA-1792 CHN-X01
' Volume Control Tank NA-1813 The NCRs, which were written against vessels provided by C-E, were sent to C-E for evaluation and resolution. The NCR for the diesel fuel oil day tank (Cooper Energy Services) was assigned to Bechtel Engineering (Norwalk) for evaluation and disposition.
Subsequent to _the construction inspection, the NRC CAT Team inspected the following seven (7) Unit 3 vessels:
Tag No.
Description Supplier / Manufacturer EWA-T01 ESS. Cool. Water Surge Tank PX Engineernig Co.
DFA-T02 Diesel Fuel Oil Day Tank Cooper Energy Services SIE-X03 Spray _ Chemical Storage Tank C-E/ Process Equipment Co.
EWB-E01 Ess. Cool Water Heat Struthers-Wells Corp.
Exchanger CHN-D02 Deborating Ion Exchanger C-E/CTI Nuclear, Inc.
CHN-E02 Letdown Heat Exchanger C-E/ Richmond Engineering Co.
CHE-E01 Regenerative Heat Exchanger C-E/Ametek The nozzle-to-shell welds on the essential cooling water surge tank and the regenerative heat exchanger were found to be in accordance with the vendor drawings. However, the nozzle-to-shell welds on the following vessels were found not to comply with their respective vendor drawings, and NCR's were issued:
?
Tag No.
Description NCR No.
DFA-T02 Diesel Fuel Oil Day Tank MG-2956 SIE-X03 Spray Chemical Storage Tank NA-1834 EWB-E01 Ess. Cool. Water Heat MA-2953 Exc hanger CHN-D02 Deborating Ion Exchanger NA-1842 CHN-E02 Letdown Heat Exchanger NA-1844 The NCRs against the C-E vessels were sent to C-E for evaluation and disposition. The NCR against the Struthers-Wells heat exchanger was sent to Struthers-Wells Corp. for evaluation and disposition. The NCR against the Cooper Energy Services tanks were assigned to Bechtel Engineering (Norwalk) for evaluation and disposition.
Evaluation the reported deficitacles from both inspections (NRC and Bechtel Construction) are evaluated below.
A.
C-E Supplied Tanks and Heat Exchangers A total of twenty-five (25) welds were reported undersized as compared to the vendor drawings. Evaluation of twenty-one (21) undersized welds indicated the welds are acceptable and in accordance with the 1975 (kinter Addenda) ASME Code Section III NC-3352.4.
Four (4) of the welds were not in accordance with ASME Code.
C-E has recommended that these welds be increased in size to be made compliant with the Code. The four (4) undersized welds meet the stress allowable per Section NC-3359 of the code, and therefore they are not safety significant. The repairs should be done, however, at the first convenient opportunity.
The following is a summary of all reported weld deficiencies:
Acceptability Equipment Under ASME Section (NCR No.)
C-E Vendor Drawing Conn.
III NC-3352.4 Deborating CTI Nuclear N001-7.05-2 A
Acceptable Ion Exchanger D
Acceptable (NCR NA-1814)
E Acceptable F
Not Acceptable Shutdown Engineers &
N001-7.03-65 N3 Acceptable Cooling Heat Fabricators Exc harger Co.
(NCR NA-1816) p-I Acceptability Equipment Under ASME Section (NCR No.)
C-E Vendor Drawing Conn.
III NC-3352.4 Letdwon Heat Richmond.Eng. N001-7.03-28 B
Not Acceptable Exc hanger Co.
F1 Acceptable (NCR NA-1793)
Hi Acceptable Spray Chemical Process N001-7.04-17 A
Acceptable Storage Tank-Equipment C
Acceptable (NCR NA-1792)
Company 3
Acceptable K
Not Acceptable Volume Control CTI Nuclear N001-7.04-4 G
Acceptable Tank K
Not Acceptable (NCR NA-1813)
B Acceptable Spray Chemical Process N001-7.04-17 B
Acceptable Storage Tank Equipment D
Acceptable (NCR NA-1834)
Company G
Acceptable J
Acceptable E
Acceptable Deborating CTI Nuc. ear N001-7.05-22 Item 5 Acceptable Ion Exchanger (NCR NA-1842)
Letdwon Heat Richmond Eng. N001-7.03-28 G1 Acceptable Exc hange r Co.
G2 Acceptable (NCR NA-1844)
D Acceptable H2 Acceptable The following is an evaluation of each of the four unacceptable welds:
1.
NCR NA-1792 - Spray Chemical Storage Tank The actual weld size of 1/8" provides inadequate nozzle
- reinforcement under ASME Code requirements and must be increased to 5/16" to provide adequate nozzle reinforcement for an external design pressure of 5 psig. Note that this is greater than the 3/16" weld leg specified on the drawing. This drawing error appears to be a design review oversight by the vendor.
ASME Code Weld strength calculations showed the 1/B" weld had adequate weld = strength but would only provide adequate nozzle reinforcement for an enternal pressure of 4.46 psig. Since there is a vacuum breaker in the line, and the normal operating external pressure is 2 psig, no f ailures would have been experienced under actual system operating conditions.
It is, however, necessary that the weld be repaired in order to meet ASME Code requirements associated with the 5 psig external design pressure...
2.
NCR NA-1814 - Deborating Ion Exchanger C-E performed ASME Code nozzle reinforcement and weld strength calculations which showed that the 5/16" weld is not overstressed and therefore does not pose a safety hazard. However, the actual weld size of 5/16" must be increased to 3/8" as specified on the drawing to be in accordance with the minimum dimensional requirements of the ASME Code.
3.
NCR NA-1813 - Volume Control Tank The actual weld size of 3/16" is inadequate and must be increased to 3/8" as specified on the drawing. ASME Code veld strength calculations showed adequate weld strength. The undersized welds would result in inadequate nozzle reinforcement for the 15 psig external design pressure. With a slight reduction in external pressure to 14.9 psig, however, the reinforcement would be adequate. Since the result of atmospheric pressure on an evacuated tank would not exceed the 14.9 psig capability, adequate assurance exists that no safety hazard is present.
4.
NCR NA-1793 - Letdown Heat Exchangc C-E performed a calculation that indicated the reduced weld size would reduce the design pressure from 650 psig to 635 psig.
Since the normal operating pressure is 460 psig, and overpressure protection is provided at 600 psig, this reduced capability would not constitute a safety hazard. However, the actual weld size of 7/16" must be increased to 1/2" as specified on the drawing to be in accordance with the ASME Code.
B.
Cooper Energy Services - Supplied Vessels A total of seven (7) welds were reported undersized. Bechtel's evaluation found five (5) of these welds to be acceptable and in accordance with ASME Code Section III NC-3352.4. Two (2) of the welds were not in accordance with ASME Code, bechtel has recommended that these welds be increased in size to be made compliant with the code. The two (2) undersized welds are not overstressed and therefore do not pose a safety hazard. The repairs should be done, however, at the first convenient opportunity.
The following is a listing of all reported weld deficiencies:
Equipment Drawing Acceptability Under (NCR No.)
No.
Conn.
ASME Code Rules Diesel Generator "B" Cooper CR101 Not Acceptable Fuel Oil Day Tank Energy Dwg.
CR104 Acceptable (NCR MG-2900)
Nos.
CR106 Acceptable KSV-51-19 &
KSV-51-19A Diesel Generator "A" Cooper CR106 Acceptable Fuel Oil Day Tank Energy Dwg.
CR107 Acceptable (NCR MG-2955)
No.
CR105 Acceptable KSV-SI-19A Manway Not Acceptable - ___________-.
The following is a discussion of each of the two (2) undersized welds.
1.
NCR MG-2900 - Diesel Generator "B" Fuel Oil Day Tank The undersized weld was analyzed (CCN No.11 to Calc. No.
13-MC-ZZ-584) and found to be capable of carrying the required loads. However, the weld does not conform to the ASME Code so it will be built-up to 3/16" all the way around.
2.
NCR MG-2956 - Diesel Generator "A" Fuel Oil Day Tank The undersized weld (intermittently 3/16") for the 24" 0.D.
Manway was analyzed (CCN No. 21 to Calc. No.13-MC-ZZ-584) and found to be capable of carrying the required loads. However, it does not meet the ASME Code minimum size requirement and will be built-up to 1/4" all the way around.
C.
Struthers-Wells Supplied Heat Exchanger A total of five (5) welds were reported undersized. Evaluation by Struthers-Wells of all five (5) welds indicated they are acceptable and in accordance with ASME Code Section III NC-3352.4.
The following is a summary of all reported weld deficiencies:
Equipment Drawing Acceptability Under (NCR No.)
No.
Connection ASME Code Rules Essential Cooling M071-68 N12 Acceptable Water Heat Exchanger M071-70 C -13 Acceptable 2
- (MA-2953)
C -14 Acceptable 1
l 143-N4 Acceptable j
144-N4 Acceptable D.
S umma ry 1.
All welds in the Bechtel Construction and NRC inspection reports were analyzed and found to be capable of carrying the required loads, and do not pose a safety hazard. However, a total of 6 welds were found to be deficient in complying with the ASME code j
requirements. These welds have been increased in size so as to meet the code. Since none of the welds were found to pose a safety significant condition, no additional inspections are required.
2.
The root cause of welds not meeting the requirements, of their respective vendor drawing, was an oversight in the vendor's Q.C.
inspection program. Also, there was an oversight in the source i
and ASME code inspections. The weld call-out on the one (1) i drawing being undersized to the ASME requirements is attributed to an oversight in the supplier's design review process.
3.
Of the welds which were found not to comply with the requirements of their respective vendor drawings, one (1) vendor drawing weld detail (Nozzle "K" on NCR No. NA-1792) was undersized with respect to the ASME code; however, this weld was determined to be sufficient to carry the required loads.
Transportaoility Since the welding details shown en the vendor fabrication drawing for the Spray Chemical Storage Tank do not meet the ASME code, all tanks supplied by this vendor (Process Equipment Co.) were reviewed for transportability. This vendor has also supplied the equipment drain tanks (tag no. CHN-X04). Calculation 13-MC-CH522R evaluated the nozzles for this tank and concluded that the as-built fillet welds are of sufficient strength to carry the imposed piping loads. The welds on the 16" and 3" nozzles comply with the ASME code requirements. There are no welding details depicted for the five (5) 1" full cauplings, therefore, a visual inspection was required. Four (4) of thecc nozzle welds (Items 7, 8,10 and 11) were found to be undersized with respect to the ASME code, however are of sufficient size to carry the imposed piping load. These findings are documented on SFR No. 3CH207, which has been dispositioned to build up these welds to meet the minimum size of 1/4" at the first available opportunity.
The above inspections, carried out for Unit 3, are considered to be representative for the components in Units 1 and 2.
Since the same ASME code procedures for f abrication and in-shop inspection were followed, similarity of the quality of the as-built conditions is answered.
II.
Analysis of Safety Implications Based upon the above, this condition is evaluated as not reportable under the requirements of 10CFR50.55(e) and 10CFR21, since if this condition were to remain uncorrected it would not represent a significant safety hazard.
III. Corrective Action 1.
NCR NA-1814 has been dispositioned to increase the weld on nozzle "F".
2.
NCR NA-1793 has been dispositioned to increase the veld on nozzle "B".
3.
NCR NA-1792 has been dispositioned to increase the weld on nozzle "K"
for the Spray Chemical Storage Tank.
4.
NCR NA-1813 has been dispositioned to increase the weld on nozzle "K" for the Volume Control Tank.
5.
NCR MG-2900 has been dispositioned to increase the weld on nozzle "CR101".
6.
NCR MG-2956 has been dispositioned to increase the weld on the 24" 0.D Manway.
7.
Per EER No. 86-XM-017, an inspection was performed on the Unit 2 Spray Chemical Storage Tank and Volume Control Tank. The results of this inspection were reviewed and the welds were found to be acceptable. Unit 1 inspections are not required based on Units 2 and 3 inspections and evaluation results, in which the welds have been found to be acceptable..
8.
EER No. 86-CH-081 has been initiated to inspect the five (5) 1" full couplings on the equipment drain tank for Units 1 and 2.
The Unit 3 inspection results for the Equipment Drain Tank found the nozzles to be at worst 1/16" undersized for a required 1/4" weld size (i.e.,
actual weld size is 3/16" minimum). Bechtel Calculation 13-MC-CH-522 documents that this 3/16" weld is of sufficient strength to carry the imposed piping loads and meet the ASME code allowables. Thus, based on the above, the Units 1 and 2 tanks are not affected, from a stress stand point. Additionally, the Units 1 and 2 tanks have been hydrostatically tested to verify weld integrity and were found to be acceptable.
9.
The active equipment vendors listed in the Condition Description have been advised of their specific deficiencies as follows:
a) B/CE-E-53534 to Combustion Engineering requested that they advise their subvendors of their respective deficiencies.
b) Cooper Energy Services has been advised of the deficiencies associated with the Diesel Fuel Oil Day Tank by Letter B/CES-E-53540, c) Struthers Wells Corporation performed an evaluation of their heat exchanger welds and this information has been incorporated into the DER Evaluation (Section III, C).
d) Tanks supplied by PX Engineering were found to be acceptable and in accordance with the vendor drawings, therefore they do not need to be advised.
Note: The above weld repairs will be made under Section XI of the ASME code.Section XI of the ASME code is being utilized since all of the deficiencies are on "N" stamped vessels. The implementation of the NCR dispositions has been completed.
EERs 86->M-017 and 86-CH-081 were issued to investigate the welds on the Units 1 and 2 equipment listed in Section IV, number seven (7) and eight (8). These welds were found to be acceptable, thus no further action is required.