ML20077L655
| ML20077L655 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 07/28/1983 |
| From: | Stewart W VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| REF-SSINS-6820 358A, IEB-82-02, IEB-82-2, NUDOCS 8308090505 | |
| Download: ML20077L655 (10) | |
Text
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W VIROINIA ELucTRIc AND POWER COMP N
?]ON [f Id RIcnnown, VIRGINIA 20261 h.3 5I All : I3 w.1..s v...
Nuca.aAm OranArno.s July 28, 1983-Mr. James P. O'Reilly Serial No. 358A Regional Administrator N0/JHL:acm Region II Docket No. 50-339 U. S. Nuclear Regulatory Commission License No. NPF-7 101 Marietta Street, Suite'2900 Atlanta, Georgia 30303
Dear Mr. O'Reilly:
VIRGINIA ELECTRIC AND POWER COMPANY NORTH ANNA POWER STATION UNIT NO. 2 RESPONSE TO ITEM 4 0F IEB 82-02 Enclosed is the Virginia Electric and Power Company response to Item 4 of IE Bulletin No. 82-02 (Degradation of Threaded Fasteners in the Reactor Coolant Pressure' Boundary of PWR Plants) for North Anna Unit No. 2 Very truly yours, W4 W. L. Stewart Enclosure cc:
Mr. M. B. Shymlock NRC Resident Inspector North Anna Power Station 8300090505 830728 DR ADOCK 05000 y
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O RESPONSE TO ITEM 4 0F IEB 82-02:
DEGRADATION OF THREADED FASTENERS IN THE REACTOR COOLANT h
PRESSURE BOUNDARIES OF PWR PLANTS
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The following information is being submitted as required by Action Item 4 of IEB 82-02 for North Anna Unit 2.
4a.
Action Item I has.been completed. Procedures have been developed
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and implemented to incorporate the maintenance training and work practices referenced in Action Item 1.
Further maintenance training, general review of the proper work practices to be utilized with threaded fasteners, is pending. Also completed are the quality assurance measures to be utilized for the proper selection, pro-curement and application of fastener lubricants.
4b.
For Action Item 2 of IEB 82-02 all threaded fasteners identified in i
the response to Action Item 3 of IEB 82-02 were inspected - at least visually. Where it was necessary to remove threaded
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fasteners for maintenance the fasteners were either reinspected as I
required prior to reuse or replaced.
See Supplement 1 for the identification of the fasteners inspected.
4c.
The following (Supplement 2) are the results of the inspections performed on the items referred to in Supplement 1.
The total staff time spent to prepare a written response for Item 4 was 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />.
The radiation exposure attributed to the initial and subsequent visual inspection was 420 mR excluding NDT inspections.
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a SUPPLEMENT 1 IDENTIFICATION OF RCPB BOLTING MATERIAL WITHIN THE SCOPE DEFINED IN IEB 82-02 i
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BASIS (1)
Steam Generator and Pressurizer manway closures (2) Valve bonnets and pump flange connections in piping 6" or greater BOLTING MATERIAL TO BE CONSIDERED l
l.
UNIT 2 1.
Loop Stop Valves i
A Loop T MOV-2590 j
H T
MOV-2591 B Loop T MOV-2592' T
MOV-2593 C
C Loop T MOV-2594 i
H T
MOV-2595 i
C 2.
Loop Stop Bypass Valves l
j A Loop MOV-2585 r-B Loop MOV-2586 r
C Loop MOV-2587 i
3.
Reactor Cooling Pump Casing And Seal Housing 2A RCP 2B RCP 2C RCP 4.
Steam Generator Manway Bolting 2A (Primary side only) 2B 2C 5.
Pressurizer Manway Bolting 2-RC-E-2 6.
R'esidual Heat Removal System MOV-2720A Isolation Valves MOV-2720B MOV-2700 MOV-2701 l
7.
S. I. Accumulator Discharge to the Loops l
SI-lK-1A (ATc) 2-SI-153 2-SI-151 l
SI-TK-1B (BTc) 2-SI-170 2-SI-188 SI-TK-lC (CTc) 2-SI-187 i
2-SI-185
I i
I (2) f 8.
Safety Injection to Loops A Loop Tc 2-SI-92 l
2-SI-91 B Loop Tc 2-SI-100 i
2-SI-99 C Loop Tc-2-SI-106 i
2-SI-105 Header to Loops MOV-2890C i
MOV-2890D I
A Loop T
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H 2-SI-117 I
2-SI-128 B Loop T 2-SI-113 H
2-SI-112 C Loop T 2-SI-125' H
2-SI-124 2-SI-126 Header to Loops MOV-2890A MOV-2890B i
9.
Pressurizer Safety Valves SV-2551A SV-2551B SV-2551C t
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s SUPPLEMENT 2 RESULTS OF THREADED FASTENER INSPECTION UNIT 2 MATERIAL EXAMINED BOLTING MATERIAL IN PLACE / REMOVED INSPECTION RESULTS 1.
Loop Stop Values IN PLACE When inspected each valve had a slight packing leak which "A" Loop T MOV-2590 H
allowed a'small amount of boric acid solution to contact a few of the fasteners. The valve was visually _ inspected with the plant at operating temperature and pressure.
"A" Loop T MOV-2591 C
No. leakage was noted, i.
"B" Loop T OV-2592 H
"B" Loop T OV-2593 C
"C" Loop T MOV-2594 H
"C" Loop T MOV-2595 C
2.~
Loop Stop Bypass Valves i
"A" Loop MOV-2585 IN PLACE MOV-2585 and 2586 had slight packing leaks. The fasteners were visually inspected and found undamaged. MOV-2587 was visually "B" Loop MOV-2586 inspected. No leakage.was noted.
"C" Loop MOV-2587 3.
Reactor Coolant Pump Casing and Seal Housing "2A" RCP IN PLACE No damage was noted to the fasteners.
i SUPPLEMENT 2 RESULTS OF THREADED FASTENER INSPECTION UNIT 2 MATERIAL EXAMINED BOLTING MATERIAL IN PLACE / REMOVED INSPECTION RESULTS 4.
Steam Generator Manway Bolting (Primary Side Only)
"2A" REMOVED The fasteners were removed and inspected visually and by Magnaflux inspection IAW 2210 and 2211 of ASME XI.
No problems "2B" were found.
"2C" 5.
Pressurizer Manway Bolting 2-RC-E-2 IN PLACE No damage to the fasteners was noted.
6.
Residual Heat Removal System Isolation Valves 2-Ril-MOV-2720A IN PLACE Botah MOV-2720A and B had slight packing leaks which allowed a small amount of Boric Acid solution to contact a few of the 2-Ril-MOV-2720B fasteners. The packing was adjusted and the fasteners visually inspected. No degradation of the fasteners was found.
7.
S.I. Accumulator Discharge To The Loops SI-TK-1A (AT )
g 2-SI-153 IN PLACE Each valve inspected visually. No problems with fasteners noted.
2-SI-151
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SUPPLEMENT 2 RESULTS OF THREADED FASTENER INSPECTION UNIT 2 MATERIAL EXAMINED BOLTING MATERIAL IN PLACE / REMOVED INSPECTION RESULTS 7.
S.I. Accumulator Discharge To The Loops (cont.)
SI-TK-1B (BT )
g 2-SI-170 IN PLACE Each valve inspected visually, No problems with fasteners noted.
2-SI-168 SI-TK-1C (CT )
g 2-SI-185 IN PLACE 2-Sl-185 was visually inspected but no problems with the fasteners were noted.
2-SI-187 REMOVED Valve bonnet on 2-SI-187 was found to have been leaking. Most of the fasteners were covered with boric acid and residue. The valve was disassembled and a new gasket installed. The valve was reassembled with new studs and nuts.
The original studs were covered with boric acid and rust but could not be non-destructively tested because they were destroyed while removing.
"A" Loop TH 2-SI-118 REMOVED.
Each valve visually inspected. No leakage and no problems with the fasteners on 2-SI-117 and 2-SI-128 were noted. Valve 2-SI-117 IN PLACE 2-SI-118 was noticed to have a body to bonnet gasket leak. The valve was disassembled and inspected. A new gasket and all 2-SI-128 studs and nuts were replaced. The original fasteners were rejected because of boric acid and rust on the threads.
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SUPPLEMENT 2 RESULTS OF THREADED FASTENER INSPECTION UNIT 2 MATERIAL EXAMINED BOLTING MATERIAL IN PLACE / REMOVED INSPECTION RESULTS 7.
S.I. Accumulator Discharge To The Loops (cont.)
"B" Loop TH 2-SI-128 IN PLACE Each valve visually inspected.
No' problems with the fasteners were noted.
2-SI-113 2-SI-125 "C" Loop Tg 2-SI-124 IN PLACE Each valve visually inspected. No problems with the fasteners were found.
2-SI-126 Header to Loops
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MOV-2890A MOV-2890A-IN PLACE Each valve visually inspected. MOV-2890A had a slight packing leak which allowed a small amount of boric acid solution to MOV-2890B MOV-2890B-REMOVED contact the fasteners. The packing was readjusted and no damage to the fasteners was noted. Valve MOV-2890B packing was leaking badly and most of the fasteners were covered with boric acid residue. The studs and nuts were removed, visually and Magnaflux inspected IAW 2210 and 2220 of ASME Section XI, and found undamaged. The valve was reassembled using the same nuts and studs and repacked.
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SUPPLEMENT 2 RESULTS OF THREADED FASTENER INSPECTION UNIT 2 MATERIAL EXAMINED BOLTING MATERIAL IN PLACE / REMOVED INSPECTION RESULTS 8.
Safety Injection to Loops "A" Loop TC IN PLACE Each valve visually inspected. No problems with the 2-SI-92 fasteners were noted.
2-SI-91 "B" Loop T C 2-SI-100 IN PLACE Each valve visually inspected.
No problems with the fasteners on 2-SI-100 were noted. The 2-SI-99 valve was 2-SI-99 REMOVED leaking through the body to bonnet gasket. The valve was disassembled, inspected and a new gasket installed. The valve was reassembled with new studs and bolts. The original studs were covered with boric acid but were not non-destructively tested because they were damagcd during removal.
I "C" Loop TC 2-SI-106 IN PLACE Each valve visually inspected.
No problems with the fasteners were,noted.
2-SI-105 Header to Loops MOV-2890C IN PLACE Each valve visually inspected.
No problems with the fasteners were noted.
MOV-2890D
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SUPPLEMENT 2 RESULTS OF THREADED FASTENER INSPECTION UNIT 2 MATERIAL EXAMINED
- BOLTING MATERIAL IN PLACE / REMOVED INSPECTION RESULTS
- 9. Pressurizer Safety Valves SV-2551A REMOVED The valves were disassembled and the studs and nuts were examined visually and by Magnaflux inspection. No problems SV-2551B were noted with any of the fasteners.
SV-2551C 1
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6 4