05000388/LER-2005-005, Regarding Reactor Automatic Scram Due to a Main Generator Lockout

Regarding Reactor Automatic Scram Due to a Main Generator Lockout

ML052280223
Person / Time
Site:	Susquehanna
Issue date:	08/05/2005
From:	Saccone R Susquehanna
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
PLA-5932 LER 05-005-00
Download: ML052280223 (5)

LER-2005-005, Regarding Reactor Automatic Scram Due to a Main Generator Lockout

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 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)(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 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications
3882005005R00 - NRC Website

text

Robert A. Saccone PPL Susquehanna, LLC Vice President - Nuclear Operations 769 Salem Boulevard X s a

Berwick, PA 18603

• Fso***

Tel. 570.542.3698 Fax 570.542.1504 rasacconeopplweb.com AUG 0 5 2005 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Stop OPI-17 Washington, DC 20555 SUSQUEHANNA STEAM ELECTRIC STATION LICENSEE EVENT REPORT 50-388/2005-005-00 LICENSE NO. NPF-22 PLA-5932 Docket No. 50-388 Attached is Licensee Event Report (LER) 50-388/2005-005-00. This event was determined to be reportable under 10 CFR 50.73(a)(2)(iv)(A) for an unplanned actuation of systems used to mitigate the consequences of significant events. On June 6, 2005, Susquehanna Unit 2 automatically scrammed in response to a generator lockout which was caused by a loss of generator field. PPL is conducting a formal root cause investigation to determine what initiated the loss of generator field and will supplement this LER by September 16, 2005.

The supplement will report the root cause and corrective actions to prevent recurrence.

The response of plant safety systems to the scram was as expected; there were no ECCS initiations or emergency diesel generator starts. Initially, two safety relief valves opened and then closed to control reactor pressure; turbine bypass valves subsequently controlled pressure. The automatic scram was an initiation of the Reactor Protection System, which was an unplanned actuation of a system designed to mitigate the consequences of a significant event. This event resulted in no actual adverse consequences to the health and safety of the public.

No commitments are associated with this LER.

Rober Saccone Vice President - Nuclear Operations Attachment Document Control Desk PLA-5932 cc:

Mr. S. Collins Regional Administrator U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 Mr. F. W. Jaxheimer Sr. Resident Inspector U.S. Nuclear Regulatory Commission P.O. Box 35 Berwick, PA 18603-0035 Mr. R. Osborne Allegheny Electric Cooperative P. 0. Box 1266 Harrisburg, PA 17108-1266 Mr. R. R. Janati Bureau of Radiation Protection Rachel Carson State Office Building P. 0. Box 8469 Harrisburg, PA 17105-8469

NRC FORM 366 U.S. NUCLEAR REGULATORY APPROVEDBY OMB: NO. 3150-0104 EXPIRES: 0630/2007 (r,,

104)Estimated

, the NRC of digits/characters for each block) may rnot conduct or sponsor, and a person Is not required to respond to, the of dgitschaactes fo eah blck)information collection.

1. FACILITY NAME Susquehanna Steam Electric Station Unit 2

2. DOCKET NUMBER

3. PAGE 05000388 1 OF3

4. TITLE Reactor Automatic Scram due to a Main Generator Lockout

5. EVENT DATE

6. LER NUMBER l

7. REPORT DATE

8. OTHER FACILITIES INVOLVED MONTH DAY YEAR YEAR SEQUENTIAL REV MONTH DAY YEAR FACILITY NAME DOCKETNUMBER lNUMBER lNO.

FACILITY NAME DOCKET NUMBER 6

6 2005 2005 005 00 8

05 2005

9. OPERATING MODE 11.THS REPORTIS SUBMInTED PURSUANTTOTHE REOUIREMENTS OF 10 CFR §: (Check all that apply) 1 Cl 20.2201 (b)

D 20.2203(a)(3)(i) 0 50.73(a)(2)(i)(C) 0 50.73(a)(2)(vii) 10 POWER LEVEL 0 20.2201(d)

D 20.2203(a)(3)(ii) a 50.73(a)(2)(ii)(A) 0 50.73(a)(2)(viii)(A) o. 20.2203(a)(1) 0 20.2203(a)(4) 0 50.73(a)(2)(ii)(B) 0 50.73(a)(2)(viii)(B) 100%

El 20.2203(a)(2)(i)

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

El 50.73(a)(2)(iii) 0 50.73(a)(2)(ix)(A) 0l 20.2203(a)(2)(ii) 0 50.36(c)(1)(ii)(A)

ED 50.73(a)(2)(iv)(A) 0 50.73(a)(2)(x) o 20.2203(a)(2)(iii) 0 50.36(c)(2)

D 50.73(a)(2)(v)(A)

El 73.71(a)(4) 0 20.2203(a)(2)(Iv)

D 50.46(a)(3)(i) 0l 50.73(a)(2)(v)(B) 0 73.71 (a)(5) o 20.2203(a)(2)(v)

El 50.73(a)(2)(i)(A) 0 50.73(a)(2)(v)(C) 0 OTHER l 20.2203(a)(2)(vi) 0 50.73(a)(2)(i)(B) 0 50.73(a)(2)(v)(D)

Specify In Abstract below or in (If more space is required, use addtiuinal copes of (If mnoe space is required, use addtionalcoopes of NRC Form 3664)

CORRECTIVE ACTIONS

Completed Actions

1) Inspected generator voltage regulator circuit for potential faults/failures.

2) Replaced possible degraded potentiometer in voltage regulator circuitry.

Planned Actions Planned Corrective Actions will be provided in a supplement to this LER based on PPL's root cause investigation.

ADDITIONAL INFORMATION

Any additional information will be provided as part of the supplement to this LER based on PPL's root cause investigation.

NRC FORM 366 (6-2004)