05000316/LER-2004-004, Re Failure to Comply with Containment Integrity Requirements Specified in Technical Specifications 3.0.4, 3.6.1.1, 3.6.1.2 and 3.6.3.1
| ML050180262 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 01/13/2005 |
| From: | Jensen J Indiana Michigan Power Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| AEP:NRC:2573-24 LER 04-004-00 | |
| Download: ML050180262 (8) | |
| Event date: | |
|---|---|
| Report date: | |
| Reporting criterion: | 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)(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)(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) 10 CFR 50.73(a)(2)(i)(B), Prohibited by Technical Specifications |
| 3162004004R00 - NRC Website | |
text
Indiana Michigan Power Company 500 Circle Drive Buchanan, MI 49107 1395 INDIANA MICHIGAN POWER January 13, 2005 AEP:NRC:2573-24 10 CFR 50.73 Docket No.
50-316 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Stop O-P1-17 Washington, DC 20555-0001 Donald C. Cook Nuclear Plant Unit 2 FAILURE TO COMPLY WITH CONTAINMENT INTEGRITY REQUIREMENTS SPECIFIED IN TECHNICAL SPECIFICATIONS 3.0.4, 3.6.1.1, 3.6.1.2, AND 3.6.3.1 In accordance with 10 CFR 50.73, "Licensee Event Report System," the following report is submitted:
Licensee Event Report (LER) 316t2004-004-00: "Failure To Comply With Requirements Specified In Technical Specifications 3.0.4, 3.6.1.1, 3.6.1.2, and 3.6.3.1 related to Containment Integrity" identifies the commitments contained in this submittal.
Should you have any questions regarding this correspondence, please contact Mr. Toby K. Woods, Compliance Supervisor, at (269) 466-2798.
Sincerely, Joseph N. Jensen Site Vice President RAJ/jen Attachments
U. S. Nuclear Regulatory Commission AEP:NRC:2573-24 Page 2 C:
J. L. Caldwell - NRC Region III K D. Curry - AEP Ft. Wayne J. T. King - MPSC C. F. Lyon - NRC Washington DC MDEQ - WHMD/HWRPS NRC Resident Inspector Records Center - INPO
ATTACHMENT 1 TO AEP:NRC:2573-24 REGULATORY COMMITMENTS The following table identifies those actions committed to by Indiana Michigan Power Company (I&M) in this document. Any other actions discussed in this submittal represent intended or planned actions by I&M. They are described to the Nuclear Regulatory Commission (NRC) for the NRC's information and are not regulatory commitments.
Commitment
Date Revise Unit 1 and Unit 2 Containment March 10, 2005 Integrity and Refueling Integrity procedures to incorporate a
comprehensive process to provide continuity of configuration controls and tracking in all modes to ensure containment integrity or containment closure capability requirements are maintained at all times (CRA 04319004-03 through -06).
Revise Unit 1 and Unit 2 Plant Heatup March 25, 2005 procedures to establish mode change signoffs prior to Mode 4 entry.
The signoffs will interface with the comprehensive configuration control process described in the above CATPR to confirm that containment integrity requirements are met prior to entry into Mode 4 (CRA 04319004-09 and -10).
The procedure 12-OHP-2110-CPS-001, March 25, 2005 "Clearance Permit System," will be re-written to incorporate additional expectations, controls, and requirements for the mode change active clearance reviews (CRA 04319004-20).
NRC Form 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB: NO. 3150-0104 EXPIRES 613012007 (6-2004)
, the NRC may not conduct or sponsor, and a person Is not required to respond to, the Information collection.
- 3. PAGE Donald C. Cook Nuclear Plant Unit # 2 05000-316 1 of 5
- 4. TITLE Failure To Comply With Containment Integrity Requirements Specified In Technical Specifications 3.0.4, 3.6.1.1, 3.6.1.2 AND 3.6.3.1 00 I
01 l
13 l 2005 MODE 4
- 11. THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR §: (Check all that apply)
O 20.2201(b) 0 20.2203(a)(3)(i) 0 50.73(a)(2)(i)(C)
E 50.73(a)(2)(vii) 0 20.2201(d) 0 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)
D 50.73(a)(2)(ii)(B) 0 50.73(a)(2)(viii)(B) o 20.2203(a)(2)(i) 0 50.36(c)(1)(i)(A) 0 50.73(a)(2)(iii) 0 50.73(a)(2)(ix)(A) o 20.2203(a)(2)(ii) 0 50.36(c)(1)(ii)(A) 0 50.73(a)(2)(iv)(A) 0 50.73(a)(2)(x) o 20.2203(a)(2)(ili) 0 50.36(c)(2) 0 50.73(a)(2)(v)(A) 0 73.71(a)(4) o 20.2203(a)(2)(iv) 0 50.46(a)(3)(ii) 0 50.73(a)(2)(v)(B) 73.71(a)(5) o 20.2203(a)(2)(v) 0 50.73(a)(2)(i)(A) 0 50.73(a)(2)(v)(C)
Li OTHER Specify In Abstract below I] 20.2203(a)(2)(vll 0 50.73(a)(2)O)(B) 01 50.73(a)(2)(v)(D or In (If more space Is required, use additional copies of NRC Form (366A)
Conditions Prior to Event
Unit 1 -MODE 1, 100%
Unit 2 - MODE 5
Description of Event
On October 29, 2004, during a Unit 2 refueling outage, a clearance was placed in effect to support non-essential service water (NESW) (KG] line flushing and leak repairs on instrument room east ventilation unit 2-HV-CIR-4. The clearance isolated and drained the NESW supply and return piping to the ventilation unit. It opened two drain valves outside containment, 2-NSW-416-4 and 2-NSW-421-4. Valve 2-NSW-416-4 is the "NESW to Instrument Room Ventilation Unit 2-HV-CIR-4 Containment Isolation Valve 2-WCR-961 Downstream Drain Valve," and valve 2-NSW-421-4 is the "NESW From Instrument Room Ventilation Unit 2-HV-CIR-4 Containment Isolation Valve 2-WCR-962 Downstream Drain Valve." These drain valves are 'A-inch gate valves in the NESW supply and return lines for 2-HV-CIR-4. They are located between the two containment isolation valves in each line. They are outside containment and are normally closed, capped, and sealed during plant operation. 2-NSW-416-4 and 2-NSW-421-4 are referred to hereafter as "the drain valves" or "the valves."
On November 5 and 6,2004, activities were under way to enter MODE 4. Procedure 02-OHP-4030-STP-010, "Containment Isolation" (STP-010), was being performed to confirm that valves were in their correct position to support containment integrity. STP-010 checks the two drain valves that were opened on the clearance. The operators performing STP-010 found the valves open, and closed and sealed them. No controls were in place to prevent the valves from being repositioned later, "undoing" STP-010. Anotherteam of operators was assigned to perform the flush ofthe ventilation unit, which was a MODE 4 constraint. They established a "temporary lift" of the clearance to support the flush and then commenced the flushing activities shortly after the other team of operators had closed the drain valves and documented their closed and sealed position on STP-0 10. The team doing the flush found the drain valves closed, which was the position needed for the flush. After the flush, they broke the seals on the drain valves and opened the valves to drain the piping for Maintenance to remove the flushing rig. This was in accordance with the restoration instructions for the "temporary lift" of the clearance, which required that the valves be restored to an open position. The operators left the area with the piping draining, and reported the opening of the valves to work control center supervision, noting that the valves needed to be restored to the closed position prior to MODE change. No additional controls were implemented or were required to be implemented.
The manager and supervisors overseeing the work did not physically ensure that the valves were re-closed after the flush.
The containment isolation surveillance procedure was still in progress when the flush was completed. Due to the incorrect assumption that surveillance STP-0 I0 would ensure the valves were closed, no additional verifications or control processes were employed, although the flushing activities impacted the position of the drain valves.
As Unit 2 escalated from MODE 5 through MODEs 4, 3, 2, and into MODE 1, reviews were performed of active clearances to ensure that no clearance-related condition impeded MODE change. The four MODE change reviews failed to identify the impact of the still-active clearance that contained the open drain valves. With the unit in operation and the drain valves open, the requirements of Technical Specifications (TS) 3.0.4, 3.6.1.1,3.6.1.2, and 3.6.3.1 were not met.
Approximately one week after entry into MODE 4, a Senior Reactor Operator began looking at active clearances to see if a path from inside to outside containment might exist, because containment pressure had not been vented recently. This led to the discovery on November 14, 2004, that the drain valves were open and containment integrity requirements were not met.
(If more space Is required, use additional copies of NRC Form (366A)
TS 3.6.1.1 requires primary CONTAINMENT INTEGRITY to be maintained in MODES I through 4. The limiting condition for operation (LCO) action requirement for TS 3.6.1.1 requires that CONTAINMENT INTEGRITY be restored within one hour or be in at least Hot Standby within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in Cold Shutdown within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.
This condition lasted longer than I hour and the requirement to be in COLD SHUTDOWN within 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> was not met. It is therefore reportable as a 60-day Licensee Event Report per 10 CFR 50.73(a)(2)(i)(B), as an Operation or Condition Prohibited by Technical Specifications.
TS 3.6.3.1 requires each containment isolation valve to be OPERABLE in MODES 1-4. Containment purge valves and locked or sealed closed valves may be opened on an intermittent basis under administrative control. With the drain valves 2-NSW-416-4 and 2-NSW-421-4 open, the associated outboard containment isolation valves were incapable of fulfilling their safety function, and no administrative control was in place to assure restoration. The LCO action requires that the inoperable containment isolation valve be restored within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. The condition exceeded 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. This is reportable under 10 CFR 50.73(a)(2)(i)(B), as an Operation or Condition Prohibited by Technical Specifications.
An assessment of the leakage pathway and test resulted in the conclusion that TS 3.6.1.2 requirements for CONTAINMENT LEAKAGE may have been exceeded had containment pressure risen above typical operating pressure.
However, at no time was pressure an issue during the affected timeframe. TS 3.6.1.2 requires that a combined leakage rate for all type B and C penetrations be less than or equal to 0.6 L. (when tested at P.)
Additionally, TS 3.0.4 requires LCO conditions to be met prior to entering an OPERATIONAL MODE where they are applicable unless other specified provisions are in place. The Unit ascended from MODE 5 to MODE I without meeting the requirements of TS 3.6.1.1 and 3.6.3.1 for MODES 1-4, and the requirements of TS 3.6.1.2 for exceeding 200 degrees Fahrenheit reactor coolant system temperature. This is reportable under 10 CFR 50.73(a)(2)(i)(B), as an Operation or Condition Prohibited by Technical Specifications.
Cause of Event
The event was caused by failure to have a comprehensive process in place to provide positive control of containment integrity or containment closure components through all MODEs of operation, and inadequate reviews of active clearances prior to MODE changes. The lack of a comprehensive process for positive control of containment integrity components allowed the drain valves to be unsealed and opened with no control in place to restore valve position beyond the clearance.
Inadequate MODE change clearance reviews resulted in failure to identify the incorrectly positioned drain valves on an active clearance.
Analvsis of Event There was no accident or significant release of radioactivity in containment during the time the valves were open.
Therefore, this event did not have an impact on public health. The event had no impact on the reactor core. This event had no industrial safety impact.
This event did have important safety significance, as reflected in the failure to meet TS requirements for containment integrity, containment leak rate, and containment isolation valves. These TS are designed to limit release of radioactive material to the environment and to limit site boundary radiation dose under accident conditions. The failure to meet TS requirements negates this protection. There was an unmonitored release path from containment atmosphere through leakage in the ventilation fan cooling coils, drained NESW piping, and out the NESW drain valves. This could have resulted in a release of containment atmosphere to the environment One containment isolation valve existed in each line (NESW supply and return) between the open drain valve and containment The containment isolation valves are designed (If more space Is required, use additional copies of NRC Form (366A) to close automatically on a Containment Isolation Phase B signal; however, a failure of one train of the Containment Isolation Phase B function would have resulted in the release paths continuing through both drain valves. For lesser accidents where containment pressure did not reach the Containment Isolation Phase B setpoint (2.9 psig), release via the unmonitored pathways could continue until manually isolated. This unmonitored release could have adversely impacted safety through increased dose following an accident.
Engineering input was obtained regarding the impact of the leakage path through the drain valves on overall containment leak rate. The leak rate was bounded by the conservative assumption that the leakage in the fan cooler was equivalent to a 1/8-inch round hole in an orifice. It was assumed that the leak path would have been isolated by the inboard containment isolation valves when containment pressure reached the Containment Isolation Phase B setpoint pressure of 2.9 psig.
Based on the information provided by engineering, flow through a 1/8-inch orifice at 3.0 psig would be greater than the 0.6 L. leakage limit for containment penetrations specified in TS 3.6.1.2.b.
A PRA-based review of this event was performed. The review concluded that there was no change in risk with respect to core damage and large early release frequency as a result of this event.
Corrective Actions
Immediate Corrective Actions:
The valves were closed, capped, and sealed.
Other clearances were reviewed to assure no other gaps existed.
Corrective Actions to Prevent Recurrence (CATPR):
Revise Unit I and Unit 2 Containment Integrity and Refueling Integrity procedures to incorporate a comprehensive process to provide continuity of configuration controls and tracking in all modes to ensure containment integrity or containment closure capability requirements are maintained at all times (CRA 04319004-03 through -06, due March 10, 2005).
Revise Unit I and Unit 2 Plant Heatup procedures to establish mode change signoffs prior to Mode 4 entry. The signoffs will interface with the comprehensive configuration control process described in the above CATPR to confirm that containment integrity requirements are met prior to entry into Mode 4 (CRA 04319004-09 and -10, due March 25, 2005).
The procedure 12-OHP-2 11 0-CPS-001, "Clearance Permit System," will be re-written to incorporate additional expectations, controls, and requirements for the mode change active clearance reviews (CRA 04319004-20, due March 25, 2005).
Other Corrective Actions:
Training will be provided for operators regarding the new process for configuration control of the containment boundary (CRA 04319004-07, due March 25, 2005).
(If more space Is required, use additional copies of NRC Form (366A)
Previous Similar Events
Unit 2 LER 05000316/2002-002-00, "Technical Specification 3.9.4.c was Violated During Core Alteration." A review of the causes and corrective actions associated with this LER demonstrated that the root cause and corrective actions for LER 05000316/2002-002-00 were substantively different and could not have prevented the event reported in this LER.
Unit 2 LER 05000316/2004-003-00, "Failure to Comply With Containment Ventilation Operability Requirements Specified In Technical Specifications 3.0.4, 3.9.4, and 3.9.9." A review of the causes and corrective actions associated with this LER demonstrated that the root cause and corrective actions for LER 05000316/2004-003-00 were substantively different and could not have prevented the event reported in this LER.