05000410/LER-2002-001, Automatic Scram Signal During Refueling Outage Due to Inadequate Instrument Air Isolation Procedure
| ML021550462 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 05/20/2002 |
| From: | Conway J Constellation Nuclear |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NMP2L 2060 LER 02-001-00 | |
| Download: ML021550462 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(iv)(A), System Actuation 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)(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)(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)(i) 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) |
| 4102002001R00 - NRC Website | |
text
P.O. Box 63 Lycomning, New York 13093 Constellation Nuclear Nine Mile Point Nuclear Station May 20, 2002 A Member of the NMP2L 2060 Constellation Energy Group United States Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 RE:
Nine Mile Point Unit 2 Docket No. 50-410 NPF-69
Subject:
Licensee Event Report 02-001, "Automatic Scram Signal During Refueling Outage Due to Inadequate Instrument Air Isolation Procedure" Gentlemen:
In accordance with 10CFR50.73(a)(2)(iv)(A), we are submitting Licensee Event Report 02-001, "Automatic Scram Signal During Refueling Outage Due to Inadequate Instrument Air Isolation Procedure."
Very truly yours, ohnT.Conway r
Site Vice President JTCIKLE/jm Attachment cc:
Mr. H. J. Miller, NRC Regional Administrator, Region I Mr. G. K. Hunegs, NRC Senior Resident Inspector Records Management
NRC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 EXPIRES 7-31-2004 (1-2001)
Estimated burden per response to comply with this mandatory information collection request:
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FACILITY NAME (1)
DOCKET NUMBER (2)
PAGE (3)
Nine Mile Point, Unit 2 05000410 1 OF 4
TITLE (4)
Automatic Scram Signal During Refueling Outage Due to Inadequate Instrument Air Isolation Procedure EVENT DATE (5)
LER NUMBER (6)
REPORT DATE (7)
OTHER FACILITIES INVOLVED (8)
MO DAY YEAR YEAR SEQUENTIAL REV MO DAY YEAR FACILITY NAME DOCKET NUMBER NUMBER NO 03 21 2002 2002 -
001 -
00 5
20 2002 FACILITY NAME DOCKET NUMBER OPERATING 5
THIS REPORT IS UBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply) (11)
MODE (9)
POWER 000 20.2201(b) 20.2203(a)(3)(ii) 50.73(a)(2)(ii)(B) 50.73(a)(2)(ix)(A)
LEVEL(10) 20.2201(d) 20.2203(a)(4) 50.73(a)(2)(iii) 50.73(a)(2)(x) 5@
20.2203(a)(1) 50.36(c)(1 )(i)(A)
X 50.73(a)(2)(iv)(A) 73.71 (a)(4) 20.2203(a)(2)(i) 50.36(c)(1 )(ii)(A) 50.73(a)(2)(v)(A) 73.71 (a)(5) 20.2203(a)(2)(ii) 50.36(C)(2) 50.73(a)(2)(v)(B)
OTHER 20.2203(a)(2)(iii) 50.46(a)(3)(ii) 50.73(a)(2)(v)(C) 20.2203(a)(2)(iv) 50.73(a)(2)(i)(A) 50.73(a)(2)(v)(D) 20.2203(a)(2)(v) 50.73(a)(2)(i)(B) 50.73(a)(2)(vii) 20.2203(a)(2)(vi) 50.73(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)
Stewart B. Minahan, Manager Unit 2 Operations L
315-349-7432 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)
CAUSE
SYSTEM COMPONENT MANU-REPORTABLE
CAUSE
SYSTEM COMPONENT MANU-REPORTABLE l
FACTURER TO EPIX 55 FACTURER TO EPIX SUPPLEMENTAL REPORT EXPECTED (14)
EXPECTED ONTH DAY YEAR SUBMISSION [YES (If yes, complete EXPECTED SUBMISSION DATE).
I X INO ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16)
On March 21, 2002, with Nine Mile Point Nuclear Station (NMPNS) Unit 2 shut down for refueling outage 8 (RFO 8),
and in mode 5, a full scram signal was received at approximately 0315 hours0.00365 days <br />0.0875 hours <br />5.208333e-4 weeks <br />1.198575e-4 months <br />. The reactor had been shut down prior to receipt of the scram signal. No control rod motion occurred as a result of the scram.
High level in the Scram Discharge Volume (SDV) generated the scram signal. The high level in the SDV occurred when air from the Service Air System (SAS) supplying the Scram Air Header (SAH) was lost and the scram valves failed open allowing water to enter the SDV. Service Air, which is supplied by the Instrument Air System (lAS), was inadvertently lost during the planned isolation of the IAS. The isolation of IAS was being done in accordance with a new procedure N2-PM-@075, Instrument Air Outage - RFO8. Service Air was lost when the IAS was isolated without ensuring that an alternate air supply to the SAS was in service.
The cause of the scram was the failure of the procedure's author and reviewers to ensure that the procedure for isolating the IAS includes steps for maintaining air supply to the SAS. Contributing causes include evolving changes in the work scope leading to late involvement of the reviewers, and insufficient time allotted for procedure validation and review.
Corrective actions include changes to procedure N2-PM-@075, review of the scram event summary by Operations technical reviewers and procedure authors, and enhancements to verification and validation checklists that are used for reviewing new or revised procedures.
NRC FORM 366 (1-2001)
(If more space is required, use additional copies of (if more space is required, use additional copies of (if more space is required, use additional copies of NRC Form 366A) (17)
V. Additional Information A. Failed Components:
none
B. Previous similar events
Prior to 1999, NMPNS Unit 2 had numerous instances where inadequate procedure preparation or review caused surveillances to be either missed or inadequately performed. In Licensee Event Report (LER) 99-06, "Inadequate Surveillance of Automatic Depressurization Nitrogen Supply System Isolation Valves," the procedural deficiency was identified as the result of a lack of knowledge, not inadequate review. LER 99-13, "Relays in Multiple Systems Were Not Correctly Tested as Required by Technical Specifications," identified the cause as an inadequate procedure due to a lack of understanding of the system test boundaries by the procedure developers and reviewers. LER 99-21, "Reactor Vessel Pressure Relays were not Correctly Tested as Required by Technical Specification Due to an Inadequate Procedure," identified the cause as an inadequate procedure resulting from an omission in the development of the procedure and the failure of reviews to identify the omission. The last revision to the procedure had been made in 1993. The weakness in the procedure was discovered as a result of corrrective actions from LER 99-13. In LER 01-004, "Reactor Scram Due to Inadequate Main Steam Isolation Valve Surveillance Procedure," an inadequate procedure was identified as the cause. However, the inadequacy was not due to lack of verification and validation of correctness of the procedure.
C. Identification of components referred to in this Licensee Event Report:
Components IEEE 805 System ID IEEE 803A Function Reactor Protection System JC N/A Main Turbine System TA N/A Control Rod Drive System AA N/A Instrument Air System LD N/A Service Air System LF N/A Breathing Air System LH N/A Valve LF ISV Turbine TA TRB Rod JC ROD