ML20058H282
| ML20058H282 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 11/07/1990 |
| From: | Thayer J YANKEE ATOMIC ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| BYR-90-142, IEB-89-002, IEB-89-2, NUDOCS 9011150117 | |
| Download: ML20058H282 (3) | |
Text
l YANKEEATOMICELECTRIC COMPANY' "Cl%'.s'eo'2*l" l
l IIF'l 580 Main Street, Bolton, Massachusetts 01740-1398 i
. YANKEE j
November 7, 1990 I
BYR 90-142 i
6 United States Nuclear Regulatory Consnission I>ocument Control Desk i
bshington, DC 20555 i
References:
(a) License No. DPR-3 (Docket No. 50-29)
(b) NRC Bulletin No. 89-02, " Stress Corrosion Cracking of High-Hardness Type 410 Stainless Stee1' Internally-Preloaded Bolting in Anchor / Darling Model S350W Swing l
Check Valves Or Valves of Similar Desige," dated July 19, 1989
Dear Sir:
i NRC Bulletin 89-02, Reference (b), identifies the failure of i
.I ASTM A193 Grade B6 Type 410 stainless steel internal bolting of swing check valves due to material stress corrosion cracking. The bulletin requires-
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inspection of Anchor / Darling swing check valve internal (preloaded) bolting, as well as swing check valves of similar design,-used in safety-related~
applications. The bulletin also requires that licensees report their results within 60 days of inspection.
Yankee has performed a review of all safety-related check valves at 9
YNPS. None were manufactured by Anchor / Darling; however, valves of similar
)
design are used in safety-related applications.
Screening criteria were employed during the review to select valves for inspection in our current refueling outage. Check valve sizes less than 2-1/2" at YNPS employ a piston l
or lif t check design which contain no internal bolting.
Likewise, a review of
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valves constructed of carbon steel indicates no use of' internal bracket bolting. The conclusion of our review was that there were a total of
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twelve (12) swing check valves, of the hanger bracket internal design, which potentially contained Type 410 bolting.
Attachment A summarizes the results of the 1990 outage inspection of swing check valves. The results of inspection are presented per Reference _(b)
(Paragraph 2) reporting requirements as follows:
('
a)
Twelve (12) check valves manufactured by'Velan Valve Company were l.
Inspected in the safety injection system at YNPS.
i b)
None of the valve-retaining block bolting removed from service was broken or cracked.
l c). Visual examinations of the Type 410 bolting revealed no surface cracking present. The subject tolting was not. reused.
l i
l 9011150117 901107 I
DR ADOCK 0500 g9
' /jj sv
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United States Nuclear Regulatory Commission November 7, 1990 Document Control Desk Page 2 i
d)
Out of 12 check valves inspected, two (2) contained "B6" bolting which t
was replaced. Bolting not clearly identified was also replaced in six (6) valves.
The replacement material was ASIM A193 Grade B8, Class I bolting as recommended by the valve supplier.. Four (4) valves contained the appropriate hanger bracket bolting (refer to Attachment A) identified by the ASTM "B8" head stamp.
e)
Since no bolting was cracked, no failure analysis was required.
Finally, engineering reviews have determined that one additional swing check valve located in the Safety Injection System contains hanger bracket l
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internal bolting. All evidence, including discussions with the valve vendor (Crane /Aloyco), has concluded that the-corrosion-resistant Aloyco design should contain similar 316 stainless internal-bracket bolting.- Stainless steel (316) bolting is not susceptible to the stress corrosion cracking concerns of Reference (b). However, for conservatism. Yankee intends to inspect the subject valve during the next scheduled refueling to verify internal bolt material.
We trust that you will find this submittal satisfactory; however, if you have any questions or require additional information, please contact us.
Very truly yours, t
YANKEE ATOMIC ELECTRIC COMPANY A
K. Thayer Vice President-Manager of Operations JKT/gjt/WPP78/62
(
Attachment cct USNRC Region I USNRC Resident Inspector, YNPS COMMONWEALTH OF MASSACHUSETTS)
)ss i
WORCESTER COUNTY
)
Then personally appeared before me J. K. Thayer, who, being duly sworn, did state that he is a Vice President of Yankee Atomic Electric Company, that I
he is duly authorized to execute and flie the foregoing document in the name and on the behalf of Yankee Atomic Electric Company and that the statemants therein are true to the best of his knowledge and belief.
dsomd i
Helen D. Sammarco Notary Public My Commission Expires November 7, 1991 t
o o
ATTACHMENT A 1990 Check Valve Inspection for IE Bulletin 89-02 Valve Number Size location Results SI-V-13 6"
LPSI Pump Discharge Bolting OK "B8" Head Marking SI-V-12 6"
LPSI Pump Discharge Bolting OK "B8" Head Marking SI-V-11 6"
LPSI Pump Discharge Bolting OK "B8" Head Marking i
SI-V-51 6"
HPSI SI Tank Suction-Line Bolting OK "B8" Head Marking SI-V-3 8"
LPSI Header Bolting Replaced "B6" Marking SI-V-2 8"
Accumulator Discharge Bolting Replaced "B6" Marking SI-V-14 4"
HPSI Discharge Header Bolting Replaced "8" HeaJ %rking SI-V-36 4"
HPSI Discharge Header Bolting Replaced "8" arJ "316" SI-V-19 4"
M. Coolant loop Bolting Replaced "8" Head Marking SI-V-21 4"
M. Coolant Loop Bolting Replaced "8" Head Marking SI-V-20 4"
M.-Coolant Loop Bolting Replaced "8" Head Marking SI-V-18' 4"
M. Coolant Loop ~
Bolting Replaced "8" Head Marking Note: Figure "8" head marking is unknown since it does not correspond to ASTM or SAE standard marking. This material has been replaced as recomunended by Velan Valve.
WPP78/62 r
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