05000249/LER-2006-001, Regarding Unit 3 Main Steam Safety Valves Exceed Surveillance Setpoint

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Regarding Unit 3 Main Steam Safety Valves Exceed Surveillance Setpoint
ML070220017
Person / Time
Site: Dresden Constellation icon.png
Issue date: 01/11/2007
From: Bost D
Exelon Generation Co, Exelon Nuclear
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
SVPLTR # 07-0003 LER 06-001-00
Download: ML070220017 (4)


LER-2006-001, Regarding Unit 3 Main Steam Safety Valves Exceed Surveillance Setpoint
Event date:
Report date:
Reporting criterion: 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications

10 CFR 50.73(a)(2)(vii), Common Cause Inoperability

10 CFR 50.73(a)(2)(i)

10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded

10 CFR 50.73(a)(2)(viii)(A)

10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition

10 CFR 50.73(a)(2)(viii)(B)

10 CFR 50.73(a)(2)(iii)

10 CFR 50.73(a)(2)(ix)(A)

10 CFR 50.73(a)(2)(iv)(A), System Actuation

10 CFR 50.73(a)(2)(x)

10 CFR 50.73(a)(2)(v)(A), Loss of Safety Function - Shutdown the Reactor

10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat

10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown

10 CFR 50.73(a)(2)(v), Loss of Safety Function
2492006001R00 - NRC Website

text

Exelkn@

Exelon Generation Company, LLC www.exeloncorp.com Nuclear Dresden Nuclear Power Station 6500 North Dresden Road 10 CFR 50.73 Morris, IL 60450-9765 SVPLTR # 07-0003 January 11,2007 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Dresden Nuclear Power Station, Unit 3 Renewed Facility Operating License No. DPR-25 NRC Docket No. 50-249

Subject:

Licensee Event Report 249/2006-001-00, "Unit 3 Main Steam Safety Valves Exceed Surveillance Setpoint" Enclosed is Licensee Event Report 249/2006-001 -00, "Unit 3 Main Steam Safety Valves Exceed Surveillance Setpoint," for Dresden Nuclear Power Station, Unit 3. This event is being reported in accordance with 10 CFR 50.73(a)(2)(i)(B), "Any operation or condition which was prohibited by the plant's Technical Specifications," and 10 CFR 50.73(a)(2)(vii)(D), "Any event where a single cause or condition caused at least one independent train or channel to become inoperable in multiple systems or two independent trains or channels to become inoperable in a single system designed to mitigate the consequences of an accident."

Should you have any questions concerning this report, please contact Mr. James Ellis, Regulatory Assurance Manager, at (815) 416-2800.

Respectfully, Dann Z

os Site Vice President Dresden Nuclear Power Station Enclosure cc:

Regional Administrator - NRC Region III NRC Senior Resident Inspector - Dresden Nuclear Power Station

NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES: 06/30/2007 (6-2004)

, the NRC may not conduct or sponsor, and a person is not required to respond to, the d ig its /c h a ra c te rs fo r e a c h b lo c k )..

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3. PAGE Dresden Nuclear Power Station, Unit 3 05000249 1 OF 3
4. TITLE Unit 3 Main Steam Safety Valves Exceed Surveillance Setpoint
5. EVENT DATE
6. LER NUMBER
7. REPORT DATE
8. OTHER FACILITIES INVOLVED T

SEUENTIAL RE SEUNTA REVFACILITY NAME DOCKET NUMBER MONTH DAY YEAR YEAR NUMBER NO.

MONTH DAY YEAR N/AN/A OPERATNG1 MOD 10R R IS I

FACILITY NAME DOCKET NUMBER 11 12 2006 2006 001 00 01 11 2007 1N/A N/A

9. OPERATING MODE
11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR§: (Check all that apply)

El 20.2201(b)

El 20.2203(a)(3)(i)

El 50.73(a)(2)(i)(C) 0 50.73(a)(2)(vii) 5 El 20.2201(d)

El 20.2203(a)(3)(ii)

El 50.73(a)(2)(ii)(A)

El 50.73(a)(2)(viii)(A)

El 20.2203(a)(1)

El 20.2203(a)(4)

[E 50.73(a)(2)(ii)(B)

E3 50.73(a)(2)(viii)(B)

El 20.2203(a)(2)(i)

El 50.36(c)(1)(i)(A)

[I 50.73(a)(2)(iii)

[] 50.73(a)(2)(ix)(A)

10. POWER LEVEL 0l 20.2203(a)(2)(ii)

[I 50.36(c)(1)(ii)(A)

El 50.73(a)(2)(iv)(A)

El 50.73(a)(2)(x)

El 20.2203(a)(2)(iii)

El 50.36(c)(2)

El 50.73(a)(2)(v)(A)

E] 73.71(a)(4) 00 20.2203(a)(2)(iv)

El 50.46(a)(3)(ii)

El 50.73(a)(2)(v)(B)

El 73.71(a)(5) 000 [I 20.2203(a)(2)(v)

El 50.73(a)(2)(i)(A)

El 50.73(a)(2)(v)(C)

El OTHER El 20.2203(a)(2)(vi)

ED 50.73(a)(2)(i)(B)

[E 50.73(a)(2)(v)(D)

Specify in Abstract below or in (If more space is required, use additional copies of NRC Form 366A) (17) modes, containment response during a loss-of-coolant accident (LOCA), and hydrodynamic loads on MSSV discharge lines. On June 2, 2006, DNPS submitted a request for a change to the TS for Units 2 and 3 to increase the allowable as-found MSSV lift setpoint tolerance from +/- 1% to +/- 3%. The required plant specific analyses to support the setpoint change had been performed for DNPS, and the results submitted to the NRC with the request for a change to the TS. This change is currently under review by the Nuclear Regulatory Commission.

D.

Safety Analysis

The safety significance of the event is minimal. DNPS had previously prepared plant specific analyses for a +/- 3% tolerance for the MSSV which addressed transient analysis, design basis overpressurization event, high pressure systems, alternate operating modes, containment response during a LOCA, and hydrodynamic loads on MSSV discharge lines. These analyses bound the as-found MSSV conditions described in this event. Therefore, the consequences of this event had minimal impact on the health and safety of the public and reactor safety.

E.

Corrective Actions

On June 2, 2006, DNPS submitted a request for a change to the TS for Units 2 and 3 to increase the allowable as-found MSSV lift setpoint tolerance from +/- 1% to +/- 3%. This change is currently under review by the Nuclear Regulatory Commission.

F.

Previous Occurrences

A review of DNPS Licensee Event Reports (LERs) for the last three years did not identify any LERs associated with multiple MSSVs removed during a refuel outage, exceeding their TS allowable as-found lift setpoints tolerance of +/- 1%.

G.

Component Failure Data

NA