IR 05000277/2010002

From kanterella
Jump to navigation Jump to search
IR 05000277-10-002 and 05000278-10-002 on 01/01/10 - 03/31/10 for Peach Bottom, Units 2 and 3, Maintenance Effectiveness
ML101320455
Person / Time
Site: Peach Bottom  Constellation icon.png
Issue date: 05/12/2010
From: Paul Krohn
Reactor Projects Region 1 Branch 4
To: Pardee C
Exelon Generation Co, Exelon Nuclear
KROHN P, RI/DRP/PB4/610-337-5120
References
IR-10-002
Download: ML101320455 (42)
v • d • e


Text

May 12, 2010

SUBJECT:

PEACH BOTTOM ATOMIC POWER STATION - NRC INTEGRATED INSPECTION REPORT 05000277/2010002 AND 05000278/2010002

Dear Mr. Pardee:

On March 31, 2010, the U. S. Nuclear Regulatory Commission (NRC) completed an integrated inspecticln at your Peach Bottom Atomic Power Station (PBAPS), Units 2 and 3. The enclosed integrated inspection report documents the inspection results, which were discussed on April 19, 2010, with Mr. William Maguire and other members of your staff.

The inspection examined activities conducted under your license as they relate to safety and compliance with the Commission's rules and regulations and with the conditions of your license.

The inspectors reviewed selected procedures and records, observed activities, and interviewed personnel.

Based Oln the results of this inspection, one self-revealing finding of very low safety significance (Green) was identified. The finding was determined to involve a violation of NRC requirements.

Additionally, a licensee-identified violation which was determined to be of very low safety significance is listed in this report. Due to the very low safety significance of the finding, and because the finding has been entered into your corrective action program (CAP), the NRC is treating the finding as a non-cited violation (NCV), consistent with Section VI.A.1 of the NRC Enforcement Policy. If you contest the NCV in this report, you should provide a response within 3D days of the date of this inspection report, with the basis for your denial, to the Nuclear Regulatory Commission, AnN: Document Control Desk, Washington, DC 20555-0001; with copies to the Regional Administrator, Region I; the Director, Office of Enforcement, U.S. NRC, Washington, DC 20555-0001; and the NRC Senior Resident Inspector at the PBAPS. In addition, if you disagree with the characterization of the cross-cutting aspect of the finding in this report, y,ou should provide a response within 30 days of the date of this inspection report. with the basis for your disagreement, to the Regional Administrator, Region 1 and the NRC Senior Resident Inspector at PBAPS. The information you provide will be considered in accordance with Inspection Manual Chapter (IMC) 0305. In accordance with Title 10 of the Code of Federal Regulations (CFR) 2.390 of the NRC's

"Rules of Practice," a copy of this letter, its enclosure. and your response (if any) will be available electronically for public inspection in the NRC Public Document Room or from the Publicly Available Records (PARS) component of the NRC's document system (ADAMS).

ADAMS is accessible from the NRC Website at http://www.nrc.gov/readfng-rm/adams.html (the Public Electronic Reading Room).

Sincerely, Paul G: Krohn, Chief Projects Branch 4 Division of Reactor Projects Docket Nos.: 50-277,50-278 License Nos.: DPR-44, DPR-56

Enclosures:

Inspection Report 05000277/2010002 and 05000278/2010002 w/Attachment: Supplemental Information

REGION I==

50-277,50-278 DPR-44, DPR-56 05000277/2010002 and 05000278/2010002 Exelon Generation Company, LLC Peach Bottom Atomic Power Station, Units 2 and 3 Delta, Pennsylvania January 1, 2010 through March 31, 2010 F. Bower, Senior Resident Inspector A. Ziedonis, Resident Inspector T. Fish, Senior Operations Engineer E. Huang, Reactor Inspector S. Pindale, Senior Reactor Inspector J. Schoppy, Senior Reactor Inspector Paul G. Krohn, Chief Reactor Projects Branch 4 Division of Reactor Projects Enclosure

SUMMARY OF FINDINGS

IR 05000277/2010002,05000278/2010002; 01/01/2010 - 03/31/2010; Peach Bottom Atomic

Power Station (PBAPS), Units 2 and 3; Maintenance Effectiveness.

The report covered a three~month period of inspection by resident inspectors and announced inspections by a senior operations engineer, two senior reactor inspectors, and one reactor inspector. One self~revealing finding was identified. The significance of most findings is indicated by their color (Green, White, Yellow, or Red) using IMC 0609, "Significance Determination Process" (SDP). Findings for which the SOP does not apply may be Green or be assigned a severity level after NRC management review. Cross-cutting aspects associated with findings are determined using Inspection IMC 0310, "Components Within The Cross-Cutting Areas," dated February 2010. The NRC's program for overseeing the safe operation of commercial nuclear power reactors is described in NUREG-1649, "Reactor Oversight Process," Revision 4, dated December 2006.

Cornerstone: Mitigating Systems

Green.

A self-revealing, Green NCVof 10 CFR 50, Appendix B, Criterion XVI,

"Corrective Action," occurred when PBAPS failed to identify and correct a condition adverse to the quality. Specifically, an issue related to control rod drive scram solenoid pilot valve (SSPV) diaphragms, as described in vendor documents and NRC generic communication, was not corrected after several slow control rods were identified during scram time testing between 2004 and 2010. Consequently, 21 slow rods were identified during Unit 2 scram time testing that was conducted from January 30 to January 31, 2010. PBAPS immediately performed maintenance to replace the defective SSPV Diagrams on a/l 21 Unit 2 slow control rods by February 1, 2010, and successfully performed post~maintenance scram time testing. Additionally, the issues were entered into the PBAPS CAP.

This finding was more than minor because it was associated with the equipment performance attribute of the Mitigating Systems (MS) cornerstone, and adversely affected the cornerstone objective of ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Using the phase 1 worksheet in Attachment 4 of IMC 0609, "Significance Determination Process," the inspectors determined that the finding affected the MS cornerstone and was of very low safety significance (Green) because it was not a design or qualification deficiency, did not represent a loss of safety system function, and was not associated with any external events. The inspectors determined that this finding had a cross-cutting aspect in the area ofproblem identification & resolution (PI&R), CAP, because PBAPS did not thoroughly evaluate previously identified conditions adverse to the quality of the SSPV diaphragms, such that the resolution addressed the cause and extent-of-condition (EOC). (Section 1 R12) [p.1 (c)]

Other Findings

A violation of very low safety significance, which was identified by the licensee, has been reviewed by the inspectors. Corrective actions taken or planned by the licensee have been entered into the licensee's CAP. This violation and the licensee's corrective action tracking numbers are listed in Section 40A7 of this report.

REPORT DETAILS

Summaty of Plant Status Unit 2 began the inspection period at 100 percent rated thermal power (RTP) where it generally remained until power was reduced to approximately 55 percent, on January 29, to perform a

. control rod pattern adjustment and testing. The control rod scram time testing identified 21 control rods that were slow when compared to Technical Specifications (TSs) requirements.

Following corrective maintenance on the control rod hydraulic control units (HCUs), the unit was returned to 100 percent RTP on February 2, where it remained until a trip of the 'A' recirculation pump on February 3 resulted in an unplanned power reduction to 40 percent. On February 4, the unit was returned to 100 percent RTP where it remained until March 12. when power was reduced to 74 percent to support planned control rod HCU maintenance. The unit was returned to 100 percent RTP on March 15, where it remained until the end of the inspection period.

Unit 3 began the inspection period at 100 percent RTP where it generally remained until January 15, when power was reduced to 60 percent to perform main turbine control valve and main feed pump maintenance. The unit was returned to 100 percent RTP on January 17, where it generally remained until March 5, when power was reduced to 74 percent to support planned control rod HCU maintenance. On March 8, the unit returned to 100 percent RTP where it remained until March 19, when power was reduced to 87 percent to support planned control rod HCU maintenance. The unit was returned to 100 RTP on March 22, where it remained until the end of the inspection period.

REACTOR SAFETY

.Cornerstones: Initiating Events, Mitigating Systems, and Barrier Integrity

==1R01 Adverse Weather Protection (71111.01 - 1 Sample)

==

.1 Event: Severe Winter Storm

a. Inspection Scope

The inspectors reviewed the site response and performance on February 11, 2010,

. immediately following a severe winter snowstorm on February 10, 2010. The inspectors toured the outside protected area, walked down the protected area boundary, plant intake structure, and emergency diesel generator (EDG) buildings, to assess the site conditions following the severe snowstorm. The inspectors discussed overall site security readiness, including any compensatory measures for the existing snow conditions, with the security shift manager to assess the adequacy of the station's physical protection. The inspectors discussed the status of the electrical grid and plant operational conditions with the operations shift manager. Additionally, the inspectors reviewed procedures for severe weather preparation, main control room logs, and.

condition reports (CRs). Documents reviewed are listed in the Attachment.

b. Findings

No findings of significance were identified.

==1R04 EguigmentAlignment (7111,1.04Q -4 Samples; 71111.04S -1 Sample)

==

.1 Partial Walkdown (4 Samples)

a. Inspection Scope

The inspectors performed a partial walkdown of four systems to verify the operability of redundant or diverse trains and components when safety-related equipment was inoperable. The inspectors performed walkdowns to identify any discrepancies that c()uld impact the function of the system and potentially increase risk. The inspectors reviewed selected applicable operations procedures, walked down system components, and verified that selected breakers, valves, and support equipment were in the correct position to support system operation. Documents reviewed are listed in the Attachment.

The four systems reviewed were:

1005;

  • Unit 2 HPCI during Unit 2 RCIC System Outage in Work Week 1010; and I
  • Units 2 & 3 E-4 Diesel Generator during E-2 Unavailability in Work Week 1014.

i

b. Findings

I I No findings of significance were identified.

.2 Complete Walkdown (1 Sample)

I

a. Inspection Scope

The inspectors performed a complete walkdown of the accessible portions of the Unit 3 RCIC system, verifying that accessible breakers, valves, and support equipment were properly aligned to support system operation. and to verify that material conditions in the plant would not challenge system operation. The inspectors reviewed system operating procedures and piping and instrumentation drawings to verify that the system alignment was appropriately translated into procedures and drawings. The inspectors discussed system operation with the plant operators, and discussed system issues and maintenance with the system engineer. Documents reviewed are listed in the

.

b. Findings

No findings of Significance were identified.

1 R05 Fire Protection (71111.050 - 5 Samples;

71111.05A - 1 Sample)

.1 Fire Protection - Tours (5 Samples)

a. Inspection Scope

The inspectors conducted fire protection walkdowns Which were focused on availability, accessibility, and the condition of firefighting equipment. The inspectors reviewed areas to assess whether PBAPS had implemented the Peach Bottom Fire Protection Plan (FPP) and adequately: controlled combustibles and ignition sources within the plant; maintained fire detection and suppression capability; and maintained the material conditio,n of passive fire protection features. For the areas inspected, the inspectors also verified that PBAPS had followed the Technical Requirements Manual (TRM) and the FPP when compensatory measures were implemented for out-of-service (OOS),degraded, or inoperable fire protection equipment, systems, or features. The inspectors verified: that fire hoses and extinguishers were in their designated locations and available for immediate use; that fire detectors and sprinklers were unobstructed; that transient combustible materials were managed in accordance with plant procedures; and fire doors, dampers, and penetration seals appeared to be in satisfactory condition.

Documents reviewed during the inspection are listed in the Attachment. The inspectors toured the following areas:

  • Unit 2 Reactor Building (RB) Sump Pump Room, Elevation 88' (Fire Zone 61);
  • Unit 2 RB 'B' and '0' Core Spray Room. Elevation 91'-6" (Fire Zone 50);
  • Unit 2 RB General Area, Elevation 165' (Fire Zone 5J);
  • Unit 3 RB South Control Rod Drive Equipment and East Corridor, Elevation 135' (Fire Zone 13P); and
  • Unit 3 RB General Area, Elevation 165' (Fire Zone 13J),

b. Findings

No findings of significance were identified.. 2

Fire Brigade Drill (1 Sample)

a. Inspection Scope

On March 5, the inspectors observed 1he performance of a fire drill scenario in the Unit 3 turbine building, 116' elevation, lubricating oil tank room (Fire Zone 88). The inspectors observed the drill to determine the readiness of the plant fire brigade to respond and combat fires. The main objective of the drill was to test the fire brigade's performance of the "two-in, two-out" approach for interior fire fighting when a member of the brigade was instructed to simulate an incapacitated state. The inspectors focused the inspection on the fire brigade response, donning of the protective gear, fire brigade leader command and control, radio communication between the fire brigade leader and main control room, execution of the "two-in, two-out" approach, conformance with the fire drill scenario, execution of the drill objectives, and returning of fire fighting equipment to a state of readiness.

The inspectors observed the post-drill critique to determine whether weaknesses and/or failures were appropriately identified, thoroughly and openly discussed in a self-critical manner, and whether appropriate training and learning opportunities were identified and discussed. The inspectors also verified that issues discussed at the post-drill critique were appropriately documented to develop corrective actions for future training.

The inspectors verified that RT-F-101-922-2, "Fire Drill," was completed to record the fire drill scenario that was used, measure performance of the drill objectives, and capture the critique results. Documents reviewed are listed in the Attachment.

.1 b.

Findings No findings of significance were identified.

1 R06 Flood Protection Measures (71111.06 - 1 Sample)

Underground Cables (1 Sample)

a. Inspection Scope

The Exelon Nuclear Cable Condition Monitoring Program is controlled under procedure ER-AA-3003, "Cable Condition Monitoring Program." The inspectors selected three manholes (MH-26, 35 and 61) with underground cables as an internal flood protection measures sample for review. The manholes were inspected under the following work control documents: action request (AR) A1744854, work order (WO) M1744676, and AR A17448853. PBAPS selected these manholes for inspection to aid in determining the EOC and corrective actions (issue report (IR) 1022206) for NCV 05000277, 278/2009005-01, "Continuously Submerged Cables Design Deficiency," that was identified in the fourth quarter of 2009.

The inspectors directly observed the interior of the subject manholes and the associated cabling after the covers had been removed. The inspectors reviewed the work instructions to ensure that PBAPS's inspections verified through direct observation:

whether the cables in manholes were submerged in water; that the cables and/or splices and their supports were not damaged or degraded; and that manhole drainage system, if installed, were functioning properly. During this sample, the inspectors observed that a portion of the cables in each of the three manholes were submerged. The inspectors also observed that the annual preventive maintenance inspection of all manholes containing safety-related and Maintenance Rule scoped cables was begun during this inspection period (WO R1132250). A list of documents reviewed is included in the

.

b. Findings

No findings of significance were identified.

1 R07 [Ieat Sink Performance (71111.07 A - 1 Sample)

a. Inspection Scope

Based on a plant specific risk assessment and a review of IRs in the CAP, the inspectors reviewed PBAPS's program for maintenance and testing of the Unit 2 'B' RHR room cooler. Specifically, the review included the program for testing and analysis of the 'B' RHR room cooler, 2FE058, over several periods of cleaning and testing from 2003 to 2010. The inspectors reviewed test results, CRs, and calculations to verify that the safety function of the RHR room cooler was maintained. The following inspection constituted one sample:

  • Unit 2 'B' RHR Room Cooler 2FE058 During this review, the inspectors evaluated an issue (IR 1020991) which was entered into the CAP regarding the unsatisfactory results of the 2 'B' RHR room cooler heat transfer test performed on January 4, 2010.

Nc) findings of significance were identified.

1 R 11 Licensed Operator Regualification Program (71111.11 Q - 1 Sample;

===71111.118 -1 Sample)

.1 Resident Inspector Quarterly Review (71111.11Q - 1 Sample)

a. Inspection Scope

On March 15, 2010, the inspectors observed two crews of operators in PBAPS's simulator during crew-led licensed operator training in preparation for requalification operating examinations. The inspectors review was conducted to verify that operator performance was adequate and to evaluate the following areas:

  • Crew's clarity and formality of communications;
  • Ability to take timely actions in the conservative direction;
  • Prioritization, interpretation, and verification of annunciator alarms;
  • Correct use and implementation of abnormal and emergency procedures;
  • Control board manipulations;
  • Oversight and direction from supervisors; and
  • Ability to identify and implement appropriate TS actions and Emergency Plan actions and notifications.

The inspectors noted that the crews' implemented combinations of several transient and special event response procedures including the following:

  • T-111, Level Restoration, Revision 12;
  • T-112, Emergency Slowdown, Revision 15;
  • SE-11, Loss of Off-Site Power, Revision 13.

This inspection constitutes one quarterly licensed operator requalmcation program s<imple per Inspection Procedure (IP) 71111.11.

b. Findings

No findings of Significance were identified.

In--office Review of Licensee Administered Annual Operating Tests and Written Exams (71111.11B-1 Sample)

a. Inspection Scope

On March 23, 2010, the inspector performed an in-office review of results of licensee~

administered annual operating tests and comprehensive written exams for 2010. The inspection assessed whether pass rates were consistent with the guidance of NRC IMC 0609, Appendix I, "Operator Requalification,Human Performance SOP." The inspectors verified that:

  • Crew failure rate was less than 20 percent. (Crew failure rate was 0 percent);
  • Individual failure rate on the dynamic simulator test was less than or equal to 20 percent. (Individual failure rate was 0 percent);
  • Individual failure rate on the walk-through test was less than or equal to 20 percent.

(Individual failure rate was 1.4 percent);

  • Individual failure rate on the comprehensive written exam was less than or equal to 20 percent. (Individual failure rate was 2.8 percent); and
  • Overall pass rate among individuals for all portions of the exam was greater than or equal to 75 percent. (Overall pass rate was 95.8 percent).

b.

findings No findings of significance were identified.

==1R12 Maintenance Effectiveness {71111.12Q - 3 Samples) a.

lrspection Scope==

The inspectors evaluated PBAPS's work practices and follow-up corrective actions for safety-related structures, systems, and components (SSCs) and identified issues to assess the effectiveness of PBAPS's maintenance activities. The inspectors reviewed the performance history of SSCs and assessed PBAPS's EOC determinations for those issues with potential common cause or generic implications to evaluate the adequacy of the PBAPS's corrective actions. The inspectors assessed PBAPS's PI&R actions for these issues to evaluate whether PBAPS had appropriately monitored, evaluated, and dispositioned the issues in accordance with Exelon procedures, including ER-AA~310.

"Implementation of the Maintenance Rule," and the requirements of 10 CFR 50.65, "Requirements for MonitOring the Effectiveness of Maintenance." In addition, the inspectors reviewed selected SSC classifications, performance criteria and goals, and PBAPS's corrective actions that were taken or planned, to evaluate whether the actions were reasonable and appropriate. Documents reviewed are listed in the Attachment.

The inspectors performed the following three samples:

  • Maintenance Rule Condition Monitoring Criteria for Control Rod Drive System (System 03) Exceeded (IRs 1035955 and 1023827);

.

  • 2 'S' Isophase Bus Fan Tripped (IRs 999398 and 1009277); and
  • Detailed Review of Maintenance Backlog for Select Systems within the Scope of the Maintenance Rule.

b. Findings

Introduction:

A self-revealing, Green NCV of 10 CFR 50, Appendix B, Criterion XVI, "Corrective Action," occurred when PBAPS failed to identify and correct a condition adverse to the quality. Specifically. an issue related to control rod drive scram solenoid pilot valve (SSPV) diaphragms, as described in vendor documents and NRC generic communication, was not corrected after several slow control rods were identified during scram time testing between 2004 and 2010. Consequently, 21 slow rods were identified during Unit 2 scram time testing that was conducted from January 30 to January 31, 2010.

Description:

On January 29,2010, during a planned load drop of Unit 2 to 55 percent power, PBAPS performed scram time testing to meet technical specification (TS)surveillance requirements (SR) 3.1.4.2 and 3.1.4.3. The periodiC surveillance testing of a representative sample (10 percent, or 19 of 185) of control rods was performed in accordance with ST~R-003-485-2, *Scram Insertion Timing of SeJectedControl Rods."

Scram times are measured from notch position 48 to four notch positions (46, 36, 26 and 06). TS Table 3.1.4-1, *Control Rod Scram Times," provides the allowable acceptance criteria for scram times to each of the four notch positions. In the initial sample of 19 control rods, three control rods were determined to be slow between control notch positions 48 and 46. As required by the TS Bases, if more than 7.5 percent of the control rods in the sample tested are determined to be "slow," additional control rods are tested until the 7.5 percent criterion is satisfied or until the total number of "slow" control rods exceeds the TS limit of 13. This resulted in all 185 control rods being tested and a total of 21 (11 percent) slow control rods identified.

Additionally, testing identified five adjacent pairs of slow control rods; however, TS 3.1.4 specifies a limit that no more than two slow but operable control rods may occupy adjacent positions. PBAPS identified these as two conditions prohibited by TS 3.1.4 (see Section 4OA3.3). During performance of the surveillance test (Sn, the slow control rods were declared inoperable and repairs were performed successfully on all 21 slow controls rods. At no time during the test was the declared number of slow control rods dliscovered to exceed the TS allowable number.

PBAPS determined that the actual reactivity effects associated with reaching rod position 46 were not significant due to the very small overlap of the blade absorber material and the actively fueled region of the reactor. Degraded scram insertion times at PBAPS required imposing minimum critical power ratio (MCPR) operating limit penalties, in order to ensure adequate safety limit margin. However, MCPR operating limit penalties were only required to be applied to control rods with degraded scram insertion times to notch position 36.

.

PBAPS captured the slow control rods in their corrective action program via issue report (IR) 1023827, and conducted a root cause evaluation. PBAPS determined that there were two root causes for the multiple slow control rods:

  • Engineering personnel missed multiple opportunities to accurately identify and take action to reduce the risk posed by a change in the degradation rate of specific Unit 2 Viton-A SSPV diaphragms; and
  • Lack of adequate surveillance test limits and failure to incorporate test results into the hydraulic control unit (HCU) maintenance program.

All 21 slow control rods contained 1995-vintage SSPV diaphragms of the Viton-A material type. Operating experience (OE) reviews performed by PBAPS, and also performed independently and in parallel by the inspectors, identified a 1996 vendor Information Letter (SIL) 584, Supplement 1, describing slower 5 percent scram insertion times (Le., notch 48 to notch 46) experienced at several boiling wat~r reactors (BWR)with Viton diaphragm material (material later referred to as Viton-A). The SIL recommended that BWR owners trend SSPV performance over time, and evaluate scram time data. NRC Information Notice 96-07 reiterated the same phenomena of slower 5 percent scram insertion times at several BWRs with Viton diaphragms. PBAPS root cause report also stated that performance monitoring and trending on the scram times was not being performed as required by Exelon procedure ER-AA-2003, "System Performance Monitoring and Analysis;" and that this trending information could have identified the degraded trend, allowing PBAPS personnel to perform corrective actions prior to the 21 Unit 2 control rods being declared TS slow.

Viton-A SSPV diaphragms on all 21 slow control rods were promptly replaced, as previously discussed above, with SSPV diaphragms of the Viton-AB material-type.

Viton-AB diaphragms were made available in 1997 by the vendor as a warranty exchange for Viton-A diaphragms. Additionally, PBAPS developed several corrective actions as a result of the root cause report, which included: replaCing all remaining Viton-A SSPV diaphragms on Unit 2 and Unit 3 with Viton-AB diaphragms, revising the HCU preventive maintenance (PM) template to establish an appropriate PM frequency for SSPV diaphragms, developing a procedure to formalize HCU system maintenance collection and evaluation of scram time test results, and standardizing actions in response to an adverse performance or trend..

Analysis:

The inspectors determined that PBAPS's failure to identify and correct a condition adverse to the quality of performance of Viton-A SSPV diaphragms, as described in vendor documents and NRC generic communication, constituted a performance deficiency. Specifically, 21 control rods were identified to have slow scram times from notch position 48 to notch position 46 during Unit 2 scram time testing that was conducted from January 30 to January 31, 2010. This finding was more than minor because it was associated with the equipment performance attribute of the Mitigating System cornerstone, and adversely affected the cornerstone objective of ensuring the reliability of systems that respond to initiating events to prevent undesirable consequences. Specifically, aged SSPV diaphragms degraded the reliability of 21 control rods that were determined to be slow according to TS requirements.

Using the Phase 1 Worksheet in Attachment 4 of IMC 0609, "Significance Determination Process," the inspectors determined that the finding was of very low safety significance (Green) because it was not a design or qualification deficiency, did not represent a loss of safety system function, and was not associated with any external events. Additionally, MCPR operating limit penalties were not required to be applied since scram insertion times to notch pOSition 36 met the TS requirements.

The inspectors determined that this finding had a cross-cutting aspect in the area of PI&R, CAP, because PBAPS did not thoroughly evaluate previously identified conditions adverse to the quality of performance of the diaphragms, such that the resolution addressed the cause and EOC [P.1 (c)]. The inspectors determined that the performance aspect described by the cross-cutting area was reflective of current performance, because PBAPS identified several slow control rods during scram time testing within the last three years.

Enforcement:

10 CFR 50, Appendix B, Criterion XVI, "Corrective Action," states in part, that measures shall be established to assure that conditions adverse to quality, such as failures, malfunctions, defiCiencies, deviations, defective material and equipment and t I I

I I

nonconformances are promptly identified and corrected. Contrary to the above, PBAPS failed to identity and correct a condition adverse to the quality of performance of the SSPV diaphragms. described in vendor documentation and NRC generic communication, after several slow control rods were identified during scram time testing between 2004 and 2010. Specifically, PBAPS did not identity the degrading trend of control rod scram times. Consequently, 21 slow rods were identified during Unit 2 scram time testing that was conducted from January 30 to January 31, 2010. PBAPS promptly performed maintenance to replace the defective SSPVs on all 21 control rods by FE~bruary 1. 2010, and successfully performed post-maintenance scram time testing.

Since this finding was of very low safety Significance (Green) and has been entered into the CAP via IR 1023827 (including a root cause analysis) this violation is being treated as an NCV, consistent with Section IV.A of the NRC Enforcement Policy. NCV 05000277/2010002-01, Inadequate Corrective Action to Address Multiple Slow Control Rods with Adverse SSPV Diaphragms.

1 R13 Maintenance Risk Assessments and Emergent Work Control (71111.13 - 6 Samples)

a. Inspection Scope

The inspectors evaluated PBAPS's implementation of the Maintenance Risk Program

'with respect to the effectiveness of risk assessments performed for maintenance activities that were conducted on SSCs. The inspectors also verified that the licensee managed the risk in accordance with 10 CFR Part 50.65(a){4} and procedure WC-AA-101, "On-line Work Control Process." The inspectors evaluated whether PBAPS had taken the necessary steps to plan and control emergent work activities and to manage overall plant risk. The inspectors selectively reviewed PBAPS's use of the online risk monitoring software and daily work schedules. The activities selected were based on plant maintenance schedules and systems that contributed to risk. Documents reviewed are listed in the Attachment. The inspectors completed six evaluations of maintenance activities on the following:

. during a lubricating Oil Pump Swap (IR 1025143);

  • Fuel Moves in Unit 2 Spent Fuel Pool (SFP) during Work Week 1002, in Preparation for SFP Rack Badger Testing (WO R1035949 and SO 18.1.A-2);
  • Unit 3 Yellow Risk Condition during RCIC System Outage in Work Week 1004;
  • Unit 3 Yellow Risk Condition during 'B' RHR Loop Planned Maintenance Outage during Work Week 1005; and
  • Availability of the Station Blackout (SBO) Electrical Source with SBO load Tap Changer in Manual Position 12 (IR 1024358).

b. Findings

No findings of significance were identified.

.1 1 R 15 0Rerability Evaluations (71111.15 - 6 Samples)

a. Inspection Scope

The inspectors reviewed six issues to assess the technical adequacy of the operability evaluations, the use and control of compensatory measures, and compliance with the licensing and design bases. Associated adverse condition monitoring plans, engineering technical evaluations, and operational and technical decision making {OTDM}

documents were also reviewed. The inspectors verified these processes were performed in accordance with the applicable administrative procedures and were consistent with NRC guidance. Specifically, the inspectors referenced procedure OP-AA-108-115, "Operability Determinations," and NRC IMC Part 9900, "Operability Determinations & Functionality Assessments for Resolutions of Degraded or Nonconforming Conditions Adverse to Quality or Safety." The inspectors also used TSs, TRM, Updated Final Safety Analysis Report (UFSAR), and associated Design Bases Documents as references during these reviews. Documents reviewed are listed in the

. The following degraded equipment issues were reviewed:

  • Elevated Tritium in Pre-developed New Monitoring Well #27 Water <IR 1032576);
  • Seismic Support for U2/U3 125/250 Volts Direct Current Station Maintenance (Standby) Battery (IR 1012102-02): and
  • Operability of the SBO Electrical Source with Alternate Control Power Configuration (Engineering Change Request (ECR) 10-00042).

With regard to IR 1032576, the inspectors reviewed this document to ensure that this new well was drilled to determine the EOC of a groundwater monitoring issue that was previously inspected and documented in NRC Inspection Report 05000277/2009005 and 05000278/2009005, Section 40A2.3.

b. Findings

No findings of significance were identified.

1 R18 Plant Modifications (71 '111.18 - 2 Samples) Permanent Modifications===

Main article: IP 71111.11

a.

Inspection SCQpe The inspectors reviewed one permanent modification to verify that modification implementation did not place the plant in an unsafe condition, particularly from a containment and decay heat removal perspective. The review was also conducted to verify that the design bases, licensing bases, and performance capability of risk significant SSCs had not been degraded as a result of these modifications. The inspectors verified the modified equipment alignment through control room instrumentation observations; UFSAR. drawings. procedures, and WO reviews; staff interviews, and plant walkdowns of accessible equipment. The following permanent modification was reviewed:

  • ECR 07-000274, Revision 0, 30P038 Pump (Unit 3 HPCI) Outboard Seal Leak No findings of significance were identified.

. 2

Temporary Modifications (1 Sample)

a. Inspection Scope

The inspectors reviewed one temporary modification listed below to ensure that installation of the modifications did not adversely affect systems important to safety. The inspectors compared the modifications with the licensing and design bases in the UFSAR and TS to verify that the modification did not affect system operability, reliability, availability, or adversely affect plant operations. The inspectors ensured that station personnel implemented the modification in accordance with the applicable temporary cCfnfigurations change process. The inspectors verified the modified equipment alignment through control room instrumentation observations, drawings, procedures, WO reviews and plant walkdowns of accessible equipment, as appropriate. The impact on existing procedures was reviewed to verify PBAPS made appropriate revisions to reflect the temporary changes. The documents reviewed are listed in the Attachment.

The following temporary modification was reviewed:

  • Unit 2 Main Turbine Thrust Bearing Wear Trip Bypass, Reactor Feed Pump (RFP)

Turbine Vibration Thrust Bearing Wear Trip Bypass and Loss of Vibration Indication (WO R1101692).

b. Findings

No findings of significance were identified.

1 R19 Post-Maintenance Testing (71111.19 - 7 Samples)

a. Inspection Scope

The inspectors observed and reviewed completed test records for selected post-maintenance testing (PMT) activities. The inspectors observed whether the tests were performed in accordance with the approved procedures or instructions and assessed the adequacy of the test methodology based on the scope of maintenance work performed. In addition, the inspectors assessed the test acceptance criteria to evaluate whether the test demonstrated that components satisfied the applicable design and licensing bases and the TS requirements. The inspectors reviewed the recorded test data to verify that the acceptance criteria were satisfied. Documents reviewed are listed in the Attachment The inspectors reviewed seven PMTs performed in conjunction with the following maintenance activities:

  • WO C0231377, performed on January 2, 2010, to conduct American Society of Mechanical Engineers (ASME)Section XI VT-2 Examination of Emergency Service Water (ESW) piping following code repair;
  • Diagnostic testing of Unit 2 HPCI MO-2~23-058 and MO-2-23-025 during Work Week 1003;
  • Partial SI3A-2-RPS-B1 FQ, Functional Test of Reactor Protection System (RPS) 'B' eard File, following replacement of Unit 3 Reactor Vessel Level Indicating Switch LlS-3-02-099B on January 21. 2010, following Spurious Unit 3 half group 1 isolation on January 21,2010;
  • ST-0-013-301-3. Unit 2 RCIC Pump, Valve, and Flow In-Service Test, performed on January 22, 2010, following a planned system maintenance outage;
  • PartiaIIC-C-11-04067, Testing and/or Replacement of Agastat Series GP. TR. and 7000 Series Relays, following replacement of Unit 2 'A' Recirculation Pump Motor Generator Set Lube Oil Pump Time Delay Relay 2A-K29A after completion of troubleshooting associated with the 2 'A' Recirculation Pump trip on February 3, 2010;
  • Diagnostic testing of Unit 2 RHR MO-2-1 0-016A and MO-2-1 0-016C during Work Week 1008; and
  • ST-O-052-212-2, E*-2 Diesel Generator Slow Start Full Load and 1ST, performed during Work Week 1014.

b. Findings

N() findings of significance were identified.

1 R22 Surveillance Testing (71111.22 - 7 Samples)a.

Inspection ScoRe (5 routine surveillances, 1 RCS Leak Detection, and 1 1ST Sample)

The inspectors reviewed and Observed selected portions of the following STs, and compared test data with established acceptance criteria to verify the systems demonstrated the capability of performing the intended safety functions. The inspectors also verified that the systems and components maintained operational readiness, met applicable TS requirements, and were capable of performing design basis functions.

Documents reviewed are listed in the Attachment. The seven STs reviewed or observed included:

  • ST-C-095-846-2, Revision 3, Gamma Isotopic AnalysiS of Unmonitored Liquid Effluents;
  • RT-R-004-995-2. Revision 1, Unit 2, Boraflex Surveillance Using the Badger Test Device, performed during Work Week 1003;
  • ST-O-52G-975-2, Units 2 & 3, Revision 2, Diesel Generator Lube Oil Inventory Verification, performed 01/14/10, 01/16/10, 01/17/10, and 01/18/10;

Pump and Valve FUnctional Inservice Test, performed 03/05/10;

Signal Auto Start with Offsite Power Available, performed 03/11/10; and

.1 Logic Circuits, in response to IR 665892: Surveillance Instruction Test Strokes Main

Steam Isolation Valve (MSIV) Unnecessarily. and IR 1034965: PCIS Group 1 Risk Mitigation during Testing.

b. Findings

No findings of significance were identified.

OTHER ACTIVITIES

{OA} 40A1 Performance Indicator (PI) Verification (71151 *6 Samples)

Cornerstone: Initiating Events and Barrier Integrity

.1 Initiating Events Pis (71151 - 6 Samples)

a. Inspection Scope

The inspectors sampled PBAPS's submittals for the Pis listed below for Units 2 and 3 for the period from January 2009 through December 2009. PI definitions and guidance c*ontained in Nuclear Energy Institute (NEI) 99-02, "Regulatory Assessment Performance Indicator Guideline," Revision 6, were used to verify the accuracy of the PI data. The inspectors reviewed selected portions of the operating logs and raw PI data, and selected applicable licensee event reports (LERs) and CAP documents from the period for each PI specified below. The inspectors compared graphical representations from the most recent PI report to the raw data and used the performance indicator definition in the NEt guideline to verify that the data were correctly reflected in the report. The fol/owing six PI samples were reviewed:

Units 2 and 3

  • Unplanned Scrams per 7,000 Critical Hours; (lE01)
  • Unplanned Scrams With Complications; and (lE03)

b. Findings

No findings of significance were identified.

40A2 Identification and Resolution of Problems (PI&R) (71152 - 2 Samples)

Review of Items Entered into the CAP a.

lJ1spection Scope As required by IP 71152, "Identification and Resolution of Problems," and in order to help identify repetitive equipment failures or specific human performance issues for follow-up. the inspectors performed screening of all items entered into the licensee's CAP. This was accomplished by reviewing the description of each new ARIIR and attending daily management review committee meetings.

b. Findings

No findings of significance were identified.

. 2 Annual Sample: Corrective Actions to Address Trip of Circuit Breaker 34-35 in Conjunction with #1 Transformer Failure (1 In-Depth. Annual Review Sample)a.

Inspection SCORe The inspectors focused on PBAPS's problem identification, evaluation. and resolution of the corrective actions to investigate the unknown cause of the trip circuit breaker 34-35 in conjunction with the #1 transformer failure (lR 811332). On July 24,2008. a fire was discovered on the alpha phase of the #1 transformer. The SU-35 and 34-35 circuit breakers tripped resulting in the loss of two out of the three offsite lines. Both units remained online and no power was lost to any safety-related equipment.

The inspectors reviewed PBAPS's immediate and follow-up actions, apparent cause evaluation, extent of condition review. and corrective actions. The inspectors conducted interviews with site personnel, completed a walkdown of related switchyard equipment, reviewed CRs, plant drawings, engineering change reviews, and vendor manuals. The documents reviewed during this inspection are listed in the Attachment.

b. Findings

& Observations No findings of Significance were identified.

The inspectors determined that PBAPS appropriately identified that the failure of circuit breaker 34~35 should not have resulted from the failure of the #1 transformer. PBAPS's apparent cause review determined that the breaker trip was due to a spurious operation of the remote manual trip circuit in response to the ground disturbance experienced with the phase-to-ground fault of the #1 transformer. PBAPS initiated and completed a design change to the circuit that was determined to prevent recurrence of this issue in the future. PBAPS also completed an EOC review and did not find any other circuit breakers in the switchyard that could be prone to the same circuit issue. In addition, Exelon initiated another review(IR 840291) to examine whether or not there was an imiependent offsite line concern.

Based on the information available, the inspectors determined that the latent error in the remote manual trip circuit design was the result of a modification, which changed the number of available TS qualified offsite sources from two to three. The modification created a vulnerability to ground transients in the remote trip circuit by having two metal oxide varistors (MOV) on each side of the manual trip coil tied to ground and one MOV in parallel with the manual trip coil. MOVs are designed to handle lightning strikes and ground transients as they shunt current away from the protective device, which in this case was the manual trip coil. However, the original protection design required simultaneous actuation of the MOVs to work. The phase-Io-ground created by the #1 transformer failure, created a ground transient larger than that of a normal lightning strike which triggered one of the MOVs tied to the ground to actuate before the other f.\\'lfo. This completed a path for the manual trip coil to actuate and open the 34-35 breaker.

. Enclosure To fix this vulnerability, Exelon removed the two MOVs tied to ground on both sides of the relay coil and kept the MOV in parallel with the relay coil in. This new protection design has been successful in dealing with lightning strikes and ground transients since implemented. Since there were no failures of the 34-35 circuit breaker or related operating experience between 1994-2008, the inspectors determined that it was not reasonably within the licensee's ability to foresee and correct the original design vulnerability. Therefore, the inspectors did not identify and performance deficiencies.

. 3 Annual Sample: ESW Piping Integrity (1 In-Depth, Annual Review Sample)

a. Inspection Scope

This inspection focused on Exelon's problem identification, evaluation, and resolution concerning several small pinhole leaks discovered in 6" ESW piping in July 2008 (lR

===798807). The affected ESW piping was common to both units and supplied cooling to the EDG coolers. In addition, ESW also supplies cooling to the ECCS room coolers, core spray pump motor oil coolers, and RHR pump seal coolers. Due to the common suction source (Conowingo Pond) and similarity in operating characteristics, the EOC review included the high pressure service water (HPSW) system. The HPSW system for each unit provides cooling water for the RHR heat exchangers under post-accident conditions.

The inspector reviewed Exelon's associated root cause analysis (RCA), EOC reView, and short and long-term corrective actions. The inspector conducted several walkdowns of accessible ESW and HPSW piping at both units to assess the material condition, EOC, and configuration control. These areas included: the EDGs, the emergency cooling water (ECW) pump, the emergency cooling tower (ECT), the ESW booster pumps, the ESW and HPSW pumps, the ECCS room coolers, the core spray pumps, and portions of the RHR heat exchangers. The inspector also reviewed ultrasonic test results, operating and IPs, engineering evaluations, related industry OE, and plant drawings. Documents reviewed are listed in the Attachment.

b. Findings

& Observations No findings of Significance were identified.

The inspector concluded that Exelon had taken timely and appropriate action in accordance with ASME Code requirements and their CAP. The inspector determined that engineering'S associated RCA was sufficiently thorough and based on the best available information, laboratory analysis, engineering analysis, and relevant industry OE. Exelon's assigned corrective actions were aligned with their identified causal factors, adequately tracked, appropriately documented, and completed as scheduled.

The inspector noted that Exelon's Management Review Committee demonstrated appropriate engagement and safety focus throughout the process (initial corrective action IR assignment, RCA review, action tracking. and effectiveness reviews).

I

40A3 Follow-up of Events and Notices of Enforcement Discretion (71153 - 3 Samples)

I

.1 Unit 2 - 'A' Reactor Recirculation Pump Trip (1 Sample)

I

a. Inspection Scope

On February 3, during a planned Unit 2 'A' reactor recirculation pump motor generator I

(MG) set lubricating oil pump swap, power was reduced to 40 percent when Unit 2 experienced a trip of the 'A' recirculation pump due to a faulty logic relay (see Section I

1F~13, 1 R 19, and 40A3. 1 ). Control rods were inserted per procedure to reduce power to I

approximately 40 percent during single loop operation. The faulty relay was replaced, I

and Unit 2 returned to 100 percent on February 4.

!

Prior to the planned MG set lubricating oil pump swap, operators conducted a pre-job i

brief and discussed the MG set lubricating oil circuitry. During a pump swap, a low lubricating oil pressure alarm condition could occur momentarily, resulting in a main control room alarm. Operators then have 15 seconds to reset the alarm prior to a trip of I

the reactor recirculation pump on the low oil pressure signal. If the alarm cannot be I.

reset within 5 seconds, the control switch for the running lube oil pump has to be placed in 'off' to reset the reactor recirculation pump trip logic. During performance of the MG I

set lube oil pump swap, the low oil pressure condition occurred momentarily, and the alarm was received. The unit reactor operator attempted to reset the alarm two times without success. The reactor operator then reported to the unit supervisor that the alarm would not reset. The plant reactor operator then prepared to place the control switch for the running lube oil pump to the off position. Before the control switch was actually placed in 'off,' the reactor recirculation MG set drive motor breaker tripped on the sealed in low oil pressure signal. Peach Bottom conducted a root cause evaluation for the operators actions (IR 1026936), and a functional failure cause determination evaluation (lR 1025143) for the failed logic relay. Laboratory analysis concluded that the failed relay was attributed to a manufacturing defect, specifically, actuator pin burrs that were cmated during the machining process.

Although operators completed all the required system operating procedure steps, they did not perform them within the strict time requirements specified In the procedure.

However, the pump trip would not have occurred if the logiC relay did not fail to perform its function due to a manufacturing defect Accordingly, the inspectors concluded that it was not reasonably within the licensee's ability to foresee and prevent the trip of the Unit 2 'A' reactor recirculation pump. Therefore, the inspectors did not identify any performance deficiencies.

b. Findings

No findings of significance were identified.

. 2 (Closed) LER 05000278f2009-07~OO, Oil Leak from MSIV Dashpot Results in Short Valve Stoke Time===

Main article: IP 79880

On September 18,2009, an engineering evaluation determined that the outboard MSIV AO-3-01A-086A did not meet its required TS minimum closure time of greater or equal to three seconds. This determination was based on MSIV stroke time testing performed on September 14, 2009, with the unit in Mode 3 entering the P3R17 outage. This condition was considered as a condition prohibited by TS since there was evidence that the condition had existed during plant operations. The cause of the event was due to not requiring preventive maintenance for the MSIV oil dashpot needle control valve. Based on troubleshooting during the refueling outage, it was determined that when the oil dashpot stroked, a small amount of oil would leak from the o-ring seal around the stem of the 3/4" needle control valve. Over time, this resulted in insufficient oil in the dash pot causing inadequate dampening of the MSIV motion. The leaking MSIV oil dashpot needle control valve was replaced. The licensee planned to upgrade the PM programs to ensure that the Units 2 and 3 MSIV needle control valves receive appropriate preventive maintenance in the future outages. There were no actual safety consequences associated with this event. PBAPS determined that this condition did not have a significant affect on the safety analysis and the plant never operated outside of the safety analysis. There were no previous similar LERs identified. The enforcement aspects of this issue are discussed in Section 40A7. The inspectors reviewed this LER and did not identify any additional violations or NRC requirements. This LER is closed.

. 3 (Closed) LER 0500021'712010-01-00, Multiple Slow Control Rods Results in Condition

Prohibited by TS (1 Sample)

With the unit operating in Mode 1 at 60 percent power fo( a planned load drop to perform maintenance and testing. a total of 21 control rods were identified to experience slow scram times from notch position 48 to 46 during testing on January 30 and 31, 2010. TS state that the number of slow operable control rods shall be limited to 13. All 185 control rods on Unit 2 were ultimately scram time tested during the surveillance test. During performance of the surveillance test, control rods were declared inoperable for repair; therefore, at no time during the test did the declared number of slow control rods exceeded the TS allowed number. This condition was reportable Since the number of slow control rods that existed during Mode 1 exceeded the number allowable by TS.

Additionally, there were five pairs of adjacent slow operable control rods identified during testing, thus exceeding the TS allowance of two adjacent slow rods. Finally, this condition was also reportable due to common cause inoperabllity, since multiple rods were inoperable in the control rod drive system during Mode 1 operations.

The cause of this event was determined to be a degradation of the 1995~vintage Viton-A diaphragms of the SSPV associated with all 21 slow control rods, and inadequate performance monitoring associated with the SSPVs. The degradation of these diaphragms resulted in delays in control rod motion, which caused the control rod notch 48 to notch 46 scram time to be slow. There were no stuck control rods and all control rods were capable of scramming to a fully inserted notch position within the TS required time. PBAPS determined there was no significant adverse impact to the control rod drive reactivity safety function. All 21 slow control rods were removed from service, the SSPV diaphragms were replaced, and the rods were re-tested satisfactorily and returned to service. There were no previous LERs involving conditions prohibited by TS with slow cClntrol rods. Previous concerns with SSPV diaphragms at PBAPS occurred in the past.

The enforcement aspects of this issue are discussed in Section 1 R12. The inspectors reviewed the LER and did not identify any additional violations of NRC requirements.

This LER is closed.

40A6 Meetings, Including Exit

.1 Quarterly Resident Exit Meeting Summary

On April 19, 2010, the resident inspectors presented the inspection results to Mr. W. Maguire and other PBAPS staff, who acknowledged the findings. Mr. P. Krohn, Chief; USNRC, Region I, Division of Reactor Projects, Branch 4, attended this quarterly inspection exit meeting. The inspectors asked the licensee whether any of the material eXamined during the inspection should be considered propriE?tary. No proprietary information was identified.

40A7 Licensee-Identified Violations The following violation of very low significance (Green) was identified by the licensee and is a violation of NRC requirements which meets the criteria of Section VI of the NRC Enforcement Policy for being dispositioned as a NCV:

  • TS Limiting Condition for Operation 3.6.1.3, Condition A, requires a main steam line flow path to be isolated within eight hours when one MSIV is inoperable in Modes 1, 2, and 3. TS 3.6.1.3, Condition F, requires the unit to be in Mode 3 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />, and Mode 4 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />, if Condition A cannot be met.

Contrary to the above, on September 18, 2009, an engineering evaluation determined that the outboard MSIV AO-3-01A-086A did not meet its required TS minimum closure time of greater or equal to three seconds. This determination was based on MSIV stroke time testing performed on September 14, 2009, when entering the P3R17 outage. This issue was considered as a condition prohibited by TS since there was evidence that the condition had existed during plant operations. The cause of the event was due to not requiring preventive maintenance for the MSIV oil dashpot needle control valve. PBAPS documented this issue in the CAP as IR 964717. Since PBAPS analysis concluded this condition did not have a significant affect on the safety analysiS and the plant never operated outside of the safety analysis, this issue is of very low (Green)safety significance. The LER associated with the event was documented in Section 40A3.2 of this report.

ATTACHMENT:

SUPPLEMENTAL INFORMATION

KEY POINTS OF CONTACT

Exelon Generation Company Personnel

W. Maguire, Site Vice President
G. Stathes, Plant Manager

J. Armstrong. Regulatory Assurance Manager

M. Weidman, Acting Engineering Director
R. Franssen, Work Management Director
J. Kovalchick, Security Manager
L. lucas, Chemistry Manager
P. Navin, Operations Director
R. Holmes, Radiation Protection Manager
T. Wasong, Training Director

NRC Personnel

P. Krohn, Branch Chief
F. Bower, Senior Resident Inspector
A. Ziedonis, Resident Inspector
T. Fish, Senior Operations Engineer
E. Huang, Reactor Inspector
S. Pindale, Senior Reactor Inspector
J. Schoppy, Reactor Inspector

LIST OF ITEMS OPENED, CLOSED, AND DISCUSSED

Opened

None

Opened/Closed

05000277/2010002-01 NCV Inadequate Corrective Action to Address Multiple Slow Control Rods with Adverse SSPV Diaphragms (Section 1R12)

.

Closed

05000278/2009-07-00 LER Oil Leak from MSIV Dashpot Results in Short Valve Stoke Time (Section 40A3.2)
05000277/2010-01-00 LER Multiple Slow Control Rods Results in Condition Prohibited by TS (Section 40A3.3)

Discussed

None

LIST OF DOCUMENTS REVIEWED

Retrieved from "https://kanterella.com/w/index.php?title=IR_05000277/2010002&oldid=5299232"