United States Nuclear Regulatory Commission - Protecting People and the Environment

General Information or Other Event Number: 39236
REP ORG: GENERAL ELECTRIC COMPANY NOTIFICATION DATE: 10/01/2002
LICENSEE: GENERAL ELECTRIC COMPANY NOTIFICATION TIME: 20:24 (EDT)
CITY: SAN JOSE REGION: 4 EVENT DATE: 10/01/2002
COUNTY: STATE: CA EVENT TIME: [PDT]
LICENSE#: AGREEMENT: Yes LAST UPDATE DATE: 10/01/2002
DOCKET: PERSON ORGANIZATION
PETE ESELG ROTH R1
JAY HENSON R2
SONIA BURGESS R3
NRC NOTIFIED BY: JASON S. POST (via fax) KRISS KENNEDY R4
HQ OPS OFFICER: MIKE NORRIS WILLIAM DEAN NRR
EMERGENCY CLASS: NON EMERGENCY VERN HODGE NRR
10 CFR SECTION:
CCCC 21.21 UNSPECIFIED PARAGRAPH

EVENT TEXT

PART 21.21 REPORT INVOLVING STABILITY OPTION III

"Subject: Stability Option Ill: Possible Successive Confirmation Count Resets

"This letter provides noUfication of a 60 Day Interim Report per º21.21(a)(2) for plants that have selected stability long-term solution Option Ill. The basis for this notification is that GE Nuclear Energy (GE) has not completed the evaluation of a potential problem with the algorithm that provides the licensing basis Minimum Critical Power Ratio (MCPR) Safety Limit protecUon for stability Option III. The algorithm determines Successive Confirmation Count (SCC) of an oscillating power signal. A reactor trip is generated when SCC and oscillation amplitude reach their trip setpoints in accordance with the Option III and reactor protection system configuration. The concern is that the oscillation period could change for an oscillation that initiates while reactor state conditions are changing rapidly (e.g.1 during a two-recirculation pump trip event) and cause the SCC to reset, thus delaying the reactor scram.

"GE believes that there is low potential for the MCPR Safety Umit to be violated as a result of this concern. However, a 60 Day Interim Report is required since the evaluation has not been completed. Further information is provided in the attached notification.

"(ii) Identification of the facility, the activity or the basic compotient supplied for such facility or such actiVity within the United States which fails to comply or contains a defect:

"The affected basic component is the Period Based Detection Algorithm (PBDA) of stability long-term solution Option III. The PEDA provides the licensing basis MCPR Safety Limit protection for anticipated coupled thermal hydraulic-neutronic reactor instabiIities. The concern is that the Successive Confirmation Count (SCC) could reset if an oscillation develops while reactor state conditions are changing rapidly (e.g., during a two recirculation pump trip event) and delay a reactor scram beyond that assumed in the licensing basis analysis. The algorithm is more susceptible to SCC resets with a period tolerance that is near to the minimum allowed by licensing documents (e.g., 50 msec). SCC resets are less likely with higher period tolerance values (e.g., 100 to 300 msec).


10101,2002 U.S. Nuclear Regulatory Commission Operations Center Event Report Page 2

General Information or Other (PAR) Event# 39236
"(iii) Identification of the firm constructing the facility or supplying the basic component which fails to comply or contains a defect:

"GE Nuclear Energy San Jose California

"(iv) Nature of the defect or failure to comply and safety hazard which is created or could be created by such defect or failure to comply:

"A reactor scram is only initiated by the PBDA when the SOC exceeds the count setpoint and the oscillation amplitude exceeds the amplitude setpoint The licensing basis is that the SOC will exceed the count setpoint before the amplitude reaches the amplitude setpoint. If the SOC resets1 then the amplitude could exceed the amplitude setpoint before SOC reaches the count setpoint. This could lead to violation of the MCPR Safety Limit.

"If scram is delayed, boiling transition could be experienced on a portion of some fuel bundles. This would be a violation of a Technical Specification Safety Umit and is reportable under 10 CFR 21. However, it would not produce a significant safety hazard or threat to public health and safety.

"(v) The date on which the information of such defect or failure to comply was obtained:

"(vi) In the case of a basic component which contains a defect or failure to comply, the number and locations of all such components in use at, supplied for, or being supplied for one or more facilities or activities subject to the regulations in this part:

"A defect has not been confirmed to exist. The potentially affected plants are listed in Attachment 2.

"(vii) The correcUve action which has been, is being, or will be taken; the name of the individual or organization responsible for the action; and the length of time that has been or will be taken to complete the action (note, these are actions specifically associated with the identified Reportable Condition):

"GE has communicated this concern to the BWR Owners' Group Potential Issues Resolution Team (PIRT) and to the Stability Detect & Suppress Committee.

"GE is continuing to evaluate the potential for the SOC to be reset for current licensed reactor operating conditions. This effort will be completed by November 18, 2002.

"(viii) Any advice related to the defect or failure to comply about the facility, activity, or basic component that has been, is being, or will be given to purchasers or licensees:

"It is recommended that potentially affected licensees keep informed through the BWR Owners' Group. No specific plant actions are recommended at this time."

Plants listed on Attachment 2
Clinton, Brunswick 1 & 2, Nine Mile Point 2, Fermi 2, Columbia, Dresden 2 & 3, LaSalle 1 & 2, Limerick 1 & 2, Peach Bottom 2 & 3, Quad Cities 1 & 2, Perry 1, Susquehanna 1 & 2, Hope Creek, Hatch 1 & 2, and Browns Ferry 1,2&3.

OCT 01 '02 05:16AM GE NUCLEAR ENERGY P.1/5

GE Nuclear Energy

General Electric Company
175 Curtner Ave. San Jose, CA 95135



October 1, 2002
02-O7NRC.DOC
MFN O2-063


Document Control Desk
United States Nuclear Regulatory Commission
One White Flint North
11555 RockviUe Pike
Rockville, Maryland 20852-2738


Subject: Stability Option III: Possible Successive Confirmafion Count Resets

This letterprovides notification of a 60 Day Interim Report per º21.21(a)(2) for plants that have selected stability long-term solution Option in. The basis for this notification is that GE Nuclear Energy (GE) has not completed the evaluation of a potential problem with the algorithm that provides the licensing basis Minimum Critical Power Ratio (MCPR) Safety Limit protection for stability Option m. The algorithm determines Successive Confirmation Count (SCC) of an oscillating power signal. A reactor trip is generated when SCC and oscillation amplitude reach their trip setpoints in accordance with the Option in and reactor protection system configuration. The concern is that the oscillation period could change for an oscillation that initiates while reactor state conditions are changing rapidly (e.g., during a two recirculation pump trip event) and cause the SCC to reset, thus delaying the reactor scram.

GE believes that there is low potential for the MCPR Safety Limit to be violated as a result of this concern. However, a 60 Day Interim Report is required since the evaluation has not been completed. Further information is provided in the attached notification.

If you have any questions, please call me at (408) 925-5362. Sincerely,




Jason. S. Post, Manager
Engineering Quality and Safety Evaluations


OCT Ol '02 05:17PM GE NUCLEAR ENERGY P.2/5

October 1, 2002
02-O7NRC.DOC
MFN 02-063


cc: S.D. Alexander (NRC-NRR/DISP/PSIB) Mail Stop 6 F2
G.C. Cwalina (NRC-NRR/DISP/PBIB) Mail Stop 6 F2
J.F. Klapproth (GB-NE)
H.J. Neems (GE-NE)
PRC File

Attachments:
1. 60 Day Interim Report per º21.21(a)(2)
2. Potentially Affected Plants

2


OCT Ol 'O2 05:17PM GE NUCLEAR ENERGY P.3/5

October 1, 2002
02-07NRC.DOC
MFN 02-063

Attachment 1-60 Day Interim Report per º2l.21(a)(2)

(i) Name and address of the individual informing the Commission:

Jason S. Post, Manager, Engineering Quality & Safety Bvaluation, GE Nuclear Energy, 175 Curtner Avenue, San Jose, CA 95125

(ii) Identification of the facility, the activity, or the basic component supplied for such facility or such activity within the United States which fails to comply or contains a defect:

The affected basic component is tile Period Based Detection Algorithm (PBDA) of stability tong-term solution Option m. The PBDA provides the licensing basis MCPR Safety Limit protection for anticipated coupled thermal hydraulic-neutronic reactor instabilities. The concern is that the Successive Confirmation Count (SCC) could reset if an oscillation develops while reactor state conditions are changing rapidly (e.g., during a two recirculation pump trip event) and delay a reactor scram beyond that assumed in the licensing basis analysis. The algorithm is more susceptible to SCC resets with a period tolerance that is near to the minimum allowed by licensing documents (e.g., 50 msec). SCC resets are less likely with higher period tolerance values (e.g., 100 to 300 msec).

(iii) Identification of the firm constructtng the facibty or supplying the basic component which fails to comply or contains a dcfect:

GE Nuclear Energy, San Jose, California

(iv) Nature of the defect or failure to comply and safety hazard which is created or could be created by such defect or failure to comply:

A reactor scram is only initiated by the P]3DA when the SCO exceeds the count setpoint and the oscillation amplitude exceeds the amplitude setpoint. The licensing basis is that the SCC will exceed the count setpoint before the amplitude reaches the aniplitude setpoint. If the SCC resets, then the amplitude could exceed the amplinide setpoint before SCC reaches the count setpoint. This could lead to violation of the MCPR Safety Limit.

If scram is delayed, boiling transition could be experienced on a portion of some fuel bundles. This would be a violation of a Technical Specification Safety Limit and is reportable under 10CFR2l. However, it would not produce a significant safety hazard or threat to public health and safety.

(v) The date on which the information of such defect or failure to comply was obtained:

August 2,2002


3

OCT 01 '02 O5:17PM GE NUCLEAR ENERGY P.4,5

October 1,2002
02-O7NRC.DOC
MFN 02-063


(vi) In the case of a basic component which contains a defect or failure to comply, the number and locations of all such components in use at, supplied for, or being supplied for one or more facilities or activities subject to the regulations in this part:

A defect has not been confirmed to exist. The potentially affected plants are listed in Attachment 2.

(vii) The corrective action which has been3 is being, or will be taken; the name of the individual or organization responsible for the action; and the length of tiine that
has been or will be taken to complete the action (note, these are actions specifically associated with the identified Reportable Condition):

GE has communicated this concern to the BWR Owners' Group Potential Issues Resolution Team (PIRT) and to the Stability Detect & Suppress Committee.

GE is continuing to evaluate the potential for the SCC to be reset for current licensed reactor operating conditions. This effort will be completed by November 18,2002.

(viii) Any advice related to the defect or failure to comply about the facility, activity, or basic component that has been, is being, or will be given to purchasers or licensees:

It is recommended that potentially affected licensees keep informed through the BWR Owners' Group. No specific plant actions are recommended at this time.


4
OCT 01, '02 05:17PM GE NUCLEAR ENERGY P.5/5

October 1,2002
02-O7NRC.DOC
MFN 02-063

Attachment 2- Potentially Affected Plants
Utility Plant
x AmerGen Energy Co. Clinton
AmerGen Energy Co. Oyster Creek
x Carolina Power & Light Co. Brunswick 1
x Carolina Power & Light Co. Brunswick 2
Constellation Nuclear Nine Mile Point 1
x Constellation Nuclear Nine Mile Point 2
x Detroit Edison Co. Fermi 2
Dominion Generation Millstone 1
x Energy Northwest Columbia
Entergy Nuclear Northeast FitzPatrick
Entergy Nuclear Northeast Pilgrim
Entergy Operations, Inc. Grand Gulf
Entergy Operations, Inc. River Bend
Entergy Nuclear Northeast Vermont Yankee
Exelon Generation Co. CRIT Facility
x Exelon Generation Co. Dresden 2
x Exelon Generation Co. Dresden 3
x Exelon Generation Co. LaSalle 1
x Exelon Generation Co. LaSalle 2
x Exelon Generation Co. Limerick 1
x Exelon Generation Co. Limerick 2
x Exelon Generation Co. Peach Bottom 2
x Exelon Generation Co. Peach Bottom 3
x Exelon Generztion Co. Quad Cities I
x Exelon Generation Co. Quad Cities 2
x FirstEnergy Nuclear Operating Co. Perry 1
Nebraska Public Power District Cooper
Nuclear Management Co. Duane Arnold
Nuclear Management Co. Monticello
Pooled Equipment Inventory Co. PIM
x PPL Susquehanna LLC. Susquehanna 1
x PPL Susquehanna LLC Susquehanna 2
x Public Service Electric & Gas Co. Hope Creek
x Southern Nuclear Operating Co. Hatch 1
x Southern Nuclear Operating Co. Hatch 2
x Tennessee Valley Authority Browns Ferry 1
x Tennessee Valley Authority Browns Ferry 2
x Tennessee Valley Authority Browns Ferry 3

5


Attachment 1 PDF Icon

Page Last Reviewed/Updated Thursday, March 29, 2012