05000331/LER-2005-001, Re Failure to Demonstrate the Capability to Achieve and Maintain Safe Shutdown Conditions
| ML052150223 | |
| Person / Time | |
|---|---|
| Site: | Duane Arnold  |
| Issue date: | 08/01/2005 |
| From: | Vanmiddlesworth G Nuclear Management Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NG-05-0421 LER 05-001-00 | |
| Download: ML052150223 (4) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(ii)(B), Unanalyzed Condition 10 CFR 50.73(a)(2)(ix)(A) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(x) 10 CFR 50.73(a)(2)(iv)(A), System Actuation 10 CFR 50.73(a)(2)(v)(B), Loss of Safety Function - Remove Residual Heat 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(i)(A), Completion of TS Shutdown 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)(viii)(A) 10 CFR 50.73(a)(2)(ii)(A), Seriously Degraded 10 CFR 50.73(a)(2)(viii)(B) |
| 3312005001R00 - NRC Website | |
text
CNu Committed to Nuclear Excellenc Duane Arnold Energy Center Operated by Nuclear Management Company, LLC August 1, 2005 NG-05-0421 10 CFR 50.73 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D.C. 20555-0001 Duane Arnold Energy Center Docket 50-331 License No. DPR-49 Licensee Event Report #2005-001-00 Please find attached the subject Licensee Event Report (LER) submitted in accordance with 10 CFR 50.73. There are no new commitments contained within this report.
Should you have any questions regarding this port, please contact this office.
Ga
. Van Middlesworth Site Vice President, Duane Arnold Energy Center Nuclear Management Company, LLC cc:
Administrator, Region III, USNRC Project Manager, DAEC, USNRC Resident Inspector, DAEC, USNRC j"
e'C-: t6-'
3277 DAEC Road
- Palo, Iowa 52324-9785 Telephone: 319.851.7611
NRC FORM 366 U.S. NUCLEAR REGULATORY APPROVED BY OMB NO. 3150-0104 EXPIRES 7-31-2004 (1-2001)
COMMISSION
, the NRC may not conduct or sponsor, and a person Is not required to respond to, the Information collection.
FACILITY NAME (1)
DOCKET NUMBER (2)
PAGE (3)
Duane Arnold Energy Center 105000331 1
of 3
TITLE (4)
Failure to Demonstrate the Capability to Achieve and Maintain Safe Shutdown Conditions EVENT DATE (5)
LER NUMBER (6)
REPORT DATE (7)
OTHER FACILITIES INVOLVED (8)
IUNAL RVFACILITY NAME DOCKET NUMBER MO DAY YEAR YEAR NSUMBER NO MO DAY YEAR FACILITY NAME DOCKET NUMBER 06 02 2005 2005 -
001 00 08 01 2005 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR 3: (Check all that apply) (11)
MODE (9) 120.2201(b) l 20.2203(a)(3)(ii) x 50.73(a)(2)(ii)(B) 50.73(a)(2)(ix)(A)
POWER 94 20.2201 (d) 20.2203(a)(4) 50.73(a)(2)(iii) 50.73(a)(2)(x)
LEVEL (1O) 20.2203(a)(1) 50.36(c)(1 )(i)(A) 50.73(a)(2)(iv)(A) 73.71 (a)(4) 20.2203(a)(2)(i)
_ 50.36(c)(1 )(ii)(A) 0.73(a)(2)(v)(A)
_ 73.71 (a)(5) 20.2203(a)(2)(ii)
_ 50.36(c)(2) 50.73(a)(2)(v)(B)
OTHER Specify In Abstract below or In 20.2203(a)(2)(iii)
_ 50.46(a)(3)(ii) 50.73(a)(2)(v)(C)
N 20.2203(a)(2)(iv) 50.73(a)(2)(i)(A) 50.73(a)(2)(v)(D)
I 20.2203(a)(2)(v)
__50.73(a)(2)(i)(B)
_50.73(a)(2)(vii) 20.2203(a)(2)(vi) 0.73(a)(2)(i)(C) 50.73(a)(2)(viii)(A) 20.2203(a)(3)(i) 50.73(a)(2)(ii)(A) 50.73(a)(2)(viii)(B)
LICENSEE CONTACT FOR THIS LER (12)
NAME TELEPHONE NUMBER (Include Area Code)
Robert Murrell, Regulatory Affairs 1319-851-7900 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)
B MANU-REPORTABLE I
MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT FACTURER TO EPIX
CAUSE
SYSTEM COMPONENT FA CTURER TO EPIX SUPPLEMENTAL REPORT EXPECTED (14)
EXPECTED MONTH DAY YEAR YES (If yes, complete EXPECTED SUBMISSION DATE).
X NO DATE (15)
SUBMI ABSTRACT (Umit to 1400 spaces, I.e., approximately 15 single-spaced typewritten lines) (i6)
On June 2, 2005, with the plant operating at 94% power in Run Mode, while reviewing an event at Monticello (LER 2005-001), it was determined that Duane Arnold Energy Center (DAEC) was vulnerable to a similar failure. Specifically, it was determined that the Remote Shutdown Panel (RSP) did not meet design criteria for Appendix R in that metering circuits in the control room could cause a lock out of an essential bus.
To correct this issue, a temporary modification was implemented on June 17, 2005.
The cause of this event was the failure to identify the potential vulnerability of the DAEC remote shutdown system design to a fault in the metering circuits.
There were no actual safety consequences associated with this event. There was no effect on public health and safety as a result of this event. This event is reportable under l
OCFR50.73(a)(2)(ii)(B).U.S. NUCLEAR REGULATORY COMMISSION (1-2001)
LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FACILITY NAME (1 DOCKET NUMBER (2.
LER NUMBER (6)
PAGE (3)
YEA SEQUENTIAL IREVISION Duane Arnold Energy Center 05000331 YEAR NUMBER ER 2005 001 00 2 of 3 [TEXT (If more space is required, use additional copies of NRC Form 366A) (17)
I. Description of Event
On June 2, 2005, with the plant operating at 94% power in Run Mode, while reviewing an event at Monticello (LER 2005-001), it was determined that Duane Arnold Energy Center (DAEC) was vulnerable to a similar failure. Specifically, it was determined that the Remote Shutdown Panel (RSP) did not meet design criteria for Appendix R in that metering circuits in the control room could cause a lock out of an essential bus (1A4). The design criteria was not met because the metering circuits are not isolated by the operation of RSP transfer switches, and could have resulted in a fault after the RSP was activated, and therefore, could have delayed the restoration of reactor vessel level. The metering circuit in question was not independent of the area, room, or zone under consideration (the control room) and therefore the remote shutdown system design did not meet the Technical Specification bases requirements for the design of the remote shutdown system. As such, this event is reportable per 1 OCFR50.72(b)(3)(ii)(B), 'Degraded or Unanalyzed Condition." As a result of this issue, a 30-day LCO (Technical Specification 3.3.3.2) for an inoperable RSP was entered on June 2, 2005.
The 30-day LCO was exited on June 18, 2005, after the installation of a temporary modification that corrected the condition.
11. Assessment of Safety Consequences
A 10CFR50.72(b)(3)(ii)(B), 'Degraded or Unanalyzed Condition" notification was made on June 2, 2005 and is listed as event number EN 41742. This report is being submitted pursuant to 1 OCFR50.73(a)(2)(ii)(B).
This event did not affect the availability of other systems needed to maintain safe shutdown conditions, remove residual heat, control the release of radioactive material, or mitigate the consequences of an accident.
Therefore, there were no actual safety consequences associated with this event. There was no effect on public health and safety as a result of this event.
There were no Safety System Functional Failures as a result of this event.
III. Cause of Event
The cause of this event was the failure to identify the potential vulnerability of the DAEC remote shutdown system design to a fault in the metering circuits, which could result in a lockout of Bus 1 A4 power supply to the RSP.
IV. Corrective Actions
On June 17, 2005, a temporary modification, TM-05-007 was implemented. This modification disconnected control room ampere meters cables in the 1A4 essential switchgear room removing the possibility of a "hot short" causing a lockout. Jumpers were installed in each 4160 Volt current transformer to keep the bus over-current protection in service.
- - U.S. NUCLEAR REGULATORY COMMISSION (1-20Q1)
LICENSEE EVENT REPORT (LER)
TEXT CONTINUATION FACILITY NAME 1l DOCKET NUMBER (2)
LER NUMBER (6)
YEAR SEQUENTIAL I REVISION Duane Arnold Energy Center 05000331 Y
NUMBER l NUMBER l
2005
-- 001 00 0
TEXT (If nore space Is required, use additional copies of NRC Form 366A) (17)
A permanent modification will be installed to permanently resolve the issue with the current monitoring circuit. This modification is due to be completed by January 30, 2006.
EIIS System and Component Codes:
N/A - no component failures occurred.
V. Additional Information
Previous Similar Occurrences:
A review of LERs at the DAEC over the last 3 years identified no LERs with similar causes.