05000388/LER-2006-001, Re Tech Specs Not Met for Inoperable ADS Pressure Switches
| ML060950420 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 03/28/2006 |
| From: | Saccone R Susquehanna |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| PLA-6033 LER 06-001-00 | |
| Download: ML060950420 (5) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications 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)(iii) 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)(i)(A), Completion of TS Shutdown 10 CFR 50.73(a)(2)(v), Loss of Safety Function |
| 3882006001R00 - NRC Website | |
text
R. A. Saccone PPL Susquehanna, LLC I a ;
Vice President - Nuclear Operations 769 Salem Boulevard A
I+ a I
Berwick, PA 18603 Tel.570.542.3959 Fax 570.542-1504 rasaccone~pplweb.com pP 1
.4 TM FIAR 29 R 200S U. S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Station OP1-17 Washington, DC 20555 SUSQUEHANNA STEAM ELECTRIC STATION LICENSEE EVENT REPORT 50-388/2006-001-00 PLA-6033 Docket 50-388 Attached is Licensee Event Report 50-388/2006-001-00. This event was determined 1:o be reportable per 10 CFR 50.73(a)(2)(i)(B), Condition Prohibited by Technical Specifications, because the presence of an incorrectly erected scaffold would have rendered two Unit 2 Automatic Depressurization System pressure switches inoperable during a seismic event. The scaffold was is place from February 1, 2005 to January 27, 2006. This duration exceeds the Technical Specification 3.3.5.1 allowable completion time for inoperable Emergency Core Cooling System Instrumentation.
The pressure switches are located on the Unit 2 'D' Residual Heat Removal pump discharge and provide a permissive signal to the Automatic Depressurization System when the 'D' RHR pump is running. Since the Automatic Depressurization System receives "pump running" permissive signals from numerous other input sources, the system's ability to perform its safety function was not affected.
There were no actual consequences to the health and safety of the public as a result of this event.
No new regulatory commitments have been created through issuance of this report.
Robert
. Saccone Vice President - Nuclear Operations Attachment
<~e2, Document Control Desk PLA-6033 cc:
'Mr. S. J. Collins Regional Administrator U. S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19408 M.r. A. J. Blamey Sr. Resident Inspector U. S. Nuclear Regulatory Commission P.O. Box 35 Berwick, PA 18603-0035 iMr. 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
I NRC FORM 366 U.S NUCLEAR REGULATORY APPROVED BY OMB: NO.3150-0104 EXPIRES: 06/30/2007
(-2004)
, the NRC may not conduct or sponsor, and a person Is not required to respon J to, the Information of digits/characters for each block) collection.
- 1. FACILITY NAME Susquehanna Steam Electric Station - Unit 2
- 2. DOCKET NUMBER
- 3. PAGE 05000388 1 OF3
- 4. TITLE Tech Specs Not Met for Inoperable ADS Pressure Switches
- 5. EVENT DATE
- 6. LER NUMBER
- 7. REPORT DATE
- 8. OTHER FACILITIES INVOLVED MONTH DAY YEAR l SEQUENTIALR REV MONTR DAY YEAR FACILITY NAME ODDCKET NUMBER NUMBER NO.
5000 FACILITY NAME DOCKET NUMBER 01 25 2006 2006 001 00 03 23 2006 05000
- 3. OPERATING MODE 11.THISREPORTISSUBMIlTlED PURSUANTTOTHE REQUIREMENTS OF 10CFR§: (Check all thatapply) 1 El 20.2201(b) al 20.2203(a)(3)(i)
El 50.73(a)(2)(i)(C)
E 50.73(a)(2)(vii) 10 POWER LEVEL El 20.2201(d)
El 20.2203(a)(3)(ii)
El 50.73(a)(2)(ii)(A)
El 50.73(a)(2)(viii)(A)
D 20.2203(a)(1)
El 20.2203(a)(4)
El 50.73(a)(2)(ii)(B)
D 50.73(at)(2)(vil)(B) 100%
20.2203(a)(2)(i)
El 50.36(c)(1)(i)(A)
D 50.73(a)(2)(iii)
D 50.73(at)(2)(ix)(A)
E 20.2203(a)(2)(ii) 0 50.36(c)(1)(ii)(A)
El 50.73(a)(2)(iv)(A)
El 50.73(a)(2)(x)
Dl 20.2203(a)(2)(iii)
El 50.36(c)(2)
El 50.73(a)(2)(v)(A)
El 73.71 (i)(4)
El 20.2203(a)(2)(iv)
El 50.46(a)(3)(ii)
El 50-73(a)(2)(v)(B)
Dl 73.71(Et)(5)
[I 20.2203(a)(2)(v)
El 50.73(a)(2)(i)(A)
Dl 50.73(a)(2)(v)(C)
El OTHER El 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, wse addiional copies of NRC Firmn 3664)
EVENT DESCRIPTION
On January 25, 2006 with Unit 2 in Mode 1 at 100% power, concerns were raised about the potential for interaction between an installed scaffold and Unit 2 'D' Residual Heat Removal (RHR; EIIS Code: BO) pump instrument tubing. The tubing feeds two Automatic Depressurization System (ADS; EIIS Code: B) pressure switches that provide an ADS initiation permissive signal when the 2 'D' RHR pump is running. Analysis has conservatively concluded that scaffold movement during a dynamic event would have challenged the function of the ADS pressure switches. Accordingly, it was assumed that the ADS pressure switches were inoperable from the time of scaffold installation on February 1, 2005 to the time the scaffold was removed on January 27, 2006. This duration exceeds the Technical Specification 3.3.5.1 allowable completion times for inoperable Emergency Core Cooling System (ECCS; EIIS Code: B) Instrumentation arid is being reported in accordance with 10 CFR 50.73(a)(2)(i)(B) as a Condition Prohibited by Technical Specifications.
CAUSE OF EVENT
Two root causes have been identified for this event:
Less than adequate scaffold program design - PPL Susquehanna's scaffold control program contains elements, such as procedural inconsistencies and insufficient training, that inhibit flawless execution.
Less than adequate reinforcement by supervision and management of administrative requirements - Supervisors and Managers of scaffold installation and inspection personnel were not reinforcing the need for workers to perform scaffold installation per procedural requirements.
ANALYSIS / SAFETY SIGNIFICANCE Function of the Unit 2 'D' RHR pump discharge (ADS permissive) pressure switches was conservatively considered suspect because of the scaffolding in the RHR pump room. Loss of these switches removed one "pump running" permissive signal from the ADS initiation logic. However, this logic incorporates multiple redundancies (any RHR pump or Core Spray loop (CS; EIIS Code: BM) in either division) that are capable of producing the pump running permissive for ADS initiation. As such, ADS would have initiated, if called upon to do so, even if a seismic event would have rendered the subject switches inoperable. The scaffold did not pose any operability concerns for the RHR system itself.
Weak programmatic controls regarding the potential impact of scaffolding on safety-related equipment did create the potential to render multiple safety-related systems, structures, and components inoperable concurrently.
(if more space is required, use addtionai copies of NRC Form 366A)
CORRECTIVE. ACTIONS The following corrective actions have been completed:
A site-wide inspection of accessible areas was initiated to identify, inspect, rework or remove scaffolding at Susquehanna.
Over 100 scaffold installations were reviewed. While numerous non-compliances with scaffold procedure requirements were identified, only the situation identified in this report rendered safety-related equipment inoperable.
The applicable procedure was revised to provide clearer guidance regarding long-term scaffolding installation and inspection requirements.
Stand-down meetings were conducted and written communications were issued to reiterate expectations regarding use of the scaffold procedure.
Efforts were undertaken to ensure scaffold installers and inspectors were properly trained and qualified to perform such cuties.
The following corrective actions are planned:
A cross-discipline team will evaluate and revise Susquehanna's scaffold control program.
Training will be completed for designated scaffolding installation and inspection personnel on the revised programmatic requirements of Susquehanna's scaffold control program.
A Maintenance management, in-plant observation process will be implemented to reinforce administrative requirements, provide coaching, and to document and trend observations.
ADDITIONAL INFORMATION
None