ML20070L832
| ML20070L832 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 03/14/1991 |
| From: | Pelletier J VERMONT YANKEE NUCLEAR POWER CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| BVY-91-26, GL-89-10, NUDOCS 9103200276 | |
| Download: ML20070L832 (4) | |
Text
_ _ _ _ _
VERMONT YANKBE NUCLBAR POWER CORPORATION i
.- #M rerry nond. Brattleboro vT 053017002 (y-);
LNGINEERING OrnCE j
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p.f'R) T/9 4 f t i March 14,1991 United States Nuclear Regulatory Conunission 11VY 9126 Document Control Desk Washington, DC 20555 i
References:
a.
License No. DPR 28 (Docket No. 50 271)
- b. -
Letter, USNRC to [ All Licensees), NVY 85 250, dated November 15,1985 (llulletin 85-03).
c.
Letter, VYNPC to USNRC,llVY 89 050, dated June 8,1989.
d.
Letter, USNRC to [ All Licensees), NVY 89 144, dated June 28,1989 (Generic Letter 8910),
c.
letter, VYNPC to USNRC, llVY 89116, dated December 28,1989.
f.
I.ctter, USNRC to VYNPC, NVY 90109, dated June 11,1990
-g.
Letter, USNRC to [All Licensees), NVY 90123, dated June 13,1990 (Supplement I to Generic letter 8910).
h.
letter, USNRC to [All Licensees], NVY 90-148, dated August 3,1990 (Supplement 2 to Generic letter 8910).
1, 1 etter, USNRC to ( All Licensees], NVY 90 198, dated October 25,1990 i
- (Supplement 3 to Generic Letter 8910).
j.
Letter, VYNPC to USNRC, IlVY 90122, dated December 14,1990.
Subject:
120 Day Response to Generic Letter 8910, Supplement 3,
- Consideration of the
- Results of NRC Sponsored Tests of Motor Operated Valves".
Dear Sir:
In Generic Letter 8910, Supilement 3 [ Reference (1)], NRC detailed three (3) specific reporting requirements. Reporting tequirement No. I requested a 30 day response, which was fulfilled by Vennont Yankee via Reference 0). Reaorting Requirement No. 2 requested a 120 day response, while Reporting Requirement No. 3 detailed conditions for a follow up submittal relative l
to changes in planned actions or schedule. The purpose of this letter is to provide Vermont Yankee's response to Reporting Requirements No. 2 and 3 of Reference (i). Reference (i) was 4
received by Vennont Yankee on November 14,1990.
Reporting Requirements Nos. 2 and 3 state the following:
- 2, Willdn 120 days of the receipt of this letter, BWR licensees shallprovide to the NRC staff the (cdlowing:
a; Criteria, refIccting operating experience and the latest test data, that were aI> plied in i
determining whether deficiencies exist in the llPCI, RCIC, and RWCU h!Ol s described l
herein (Reference (ill, in the A1OVs in isolation condenser lines, and in any A10Vs considered to be more sqfety significant, as applicable;
- b. The identification ofany h10Vsfound to have deficiencies; and M
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United States Nuclear Regulatory Commission March 14,1991 Page 2
- c. A schedulefor any necessary corrective actions.
- 3. Subsequent to the determination of necessary corrective actions or the establishment of the schedule for cornpletion of those actions, BWh licensees shall irform the NRC stqff of any changes to the plant.ed actions or schedule.
Please find Vermont Yankee's criteria, as requested by Reporting Requirement No. 2, item (a), attached to this letter. As detailed in this attachment, no safety significant deficiencies have been identified at Vemiont Yankee with regard to the subject valves. As such, no corrective action is deemed necessary.
Vermont Yankee considers all actions and reporting requirements under Generic Letter 89-10, Supplement 3 [peference (i)] to be complete. We trust that this information is responsive to your request; however, should you have additional questions or require additional information, please contact this office.
Very truly yours, VERMONT YANKEE NUCLEAR POWER CORPORATION 771M Lh f ames P. Pelletier Vice President - Engineering cc:
USNRC Region 1 Administrator USNRC Resident inspector VYNPS USNRC Project Manager VYNPS STATEOPVERMONT )
) ss WINDllAM COUNTY )
Then personally appeared before me, James P. Pelletier, who, being duly sworn, did state that he is Vice President Engineering of Vermont Yankee Nuclear Power Corporation, that he is duly authorized to execute and file the foregoing document in the name and on the behalf of Vermont Yankee Nuclear Power Corporation and that the statements therein are true to the best of his knowledge and belief, w.
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p_ETERMINATION OF DEFICIENCIE.]
The 'as is' capability of the Line Break valves at Vermont Yanken are shown in Tablo 1.
No safety significant defielencies have been identified. A safety significant deficiency is one that could prevent the motor operator from performing its required safety function, such as an inadequate thrust or an incorrect setting.
Vermont Yankee used the following information to determine the existence of any safety significant deficiency: dynamic dp teste performed at Vermont Yankee, Information Notice (IN) 90 40 and IN 90 72.
At Vermont Yankoe, the HPCI valves are Walworth valves. INEL testing Indicated that Walworth valves generally required less thrust than the other valves tested (Velan and Anchor / Darling).
Also, IN 90 40 notes that Walworth valves were bounded by a valve factor of 0.5 and were not bounded by a valve factor of 0.3. Therefore, a Walworth valve with a valve factor between 0.3 and 0.5 may be indeterminate based upon IN 90-40, and another method must be used to determine adequacy.
A differential pressure test was performed at Vermont Yankoe on a Walworth valve, identical in size and model, and in the same steam line downstream of the HPCI 15 and 16 isolation valves. This dynamic dp test, performed (as part of Bulletin 85-03) at 998 psl differentici (psid) and full HPCI turbine steam flow, showed that this valve required a lower valve factor than the currently available valve factors in the HPCI 15 and 16 isolation valves.
In addition, the MOVATs database is used to determine the thrust output for the calculated maximum dp at Vermont Yankee. The MOVATs database is inherently conscrvativo, except for anomalles in the comprised test data, since it contains mostly valves other than Walworth valves. These other valves have been proven, via NRC sponsored testing, to generally requito more thrast for a differential pressure than Walworth valves. Vermont Yankoo concludes that the HPCI 15 and 19 valves would perform their line break isolation function.
The RCIC valves at Vermont Yankeo are Walworth valves. INEL testing Indicated that Walworth valves required less thrust than the other valves tested (Volan and Anchor /Darilog). Also, based upon IN 90-40, Walworth valves were bounded by a valvo factor of 0.5 and weie not bounded by a valve factor of 0.3.
Even though the valves that INEL used in their tests v, ore larger than Vermont Yankee's, the similarity of valve factors for different sizes remairm go5erally the same.
The effective valve factor at torque switch trip for the Vermont Yankee W 15 and 16 valves are In excess of 1.02. Vermant Yankee concludes that these valves e perform their line break Isolation function.
The RWCU valves at Vermont Yankee are William Powell valves. INEL testing indicated that William Powell valves required less thrust than the other valves tested (Velan and Anchor / Darling).
Also, based upon IN 90-40, William Powell valves were bounded by 0.5 valve factor At Vermont Yankee, full motor torque is used to close these valves. The effective valve factor for the Vermont Yankoe RWCU 15 and 18 valves are in excess of 0.65. Vermont Yankee concludes that these valves would perform their line break Isolation function.
The Rectre valves at Vermont Yankee are Darling valves. These valves are of a different design than those valves tested in IN 90 40.
The info notice does not give any guidance to an acceptable valve factor for Darling valves. IN 90 72 provides the only guidance available for this type of valvo design. Based upon this guidance, a 0.4 valve factor is adoquato. At Vermont Yankee, full motor torque is used to close these (Recirc line break) valves. The discharge valves (2 53 A,B) have an effective valve factor of 0.59 and the dischargo bypass valves (2 54 A,B) have an effective valve factor of 1.63. Vermont Yankee concludes that these valves would perform their line break isolation function.
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-. _ -. ~ - - -..._~...-.--.-. ~.- - - -
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Vermont Yankee closely follows the industry efforts, in testing and other areas, trying to determine the prodletability of MOVs. Vermont Y6nkee will continue to follow these Industry efforts and assoas the conclusions of these efforts on the operability of our MOVs.
No safety significant deficiencies have been identified in the MOVs shown in. Table 1, As such, no corrective action is necessary.
. Table 1
.t System Valve Manufacturer Size Orifice - dP Close Effective Valve ID '
Thrust Factor Ilnches) Ilnehet) fosidi Inounds)
HPCI 23 15 Walworth 10 8.25 1080 -28135 1
.40 -
. HPCI 23 16-Walworth 10 8 25- -1080 28339 1
.41 RCIC 13 15 Walworth 3
2.624 1080 8000 1 1.05
- RCIC 13 16' Walworth 3-2.624 1080 7780 1 1.02 RWCU 12 15 Wm. Powell. 4 3.693 1089 10475 2
.68
-RWCU-12 18 Wm. Powell 4
3.624 1089 9852 2
.65 Recire 2 53A,B' Darling 28 19.375' 280 53147 2.59 Recirc 2 54A,8 Darling 4
4 0625 280 7725 2 1.63 NOTES:
- 1) At Torque Switch Trip
- 2) Full Motor Torque (at undervoltage condition), TS Bypassed 99%
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