ML18153A022

Monthly Operating Repts for June 1996 for Surry Power Station Units 1 & 2.W/960711 Ltr

ML18153A022
Person / Time
Site:	Surry
Issue date:	06/30/1996
From:	BOWLING M L, MASON D, OLSEN C VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
96-354, NUDOCS 9607190023
Download: ML18153A022 (19)

Text

( e e VIRGINIA ELECTRIC A]S"D POWER COMPANY RICHMOND, VIRGINIA 23261 July 11, 1996 U. S. Nuclear Regulatory Commission Attention:

Document Control Desk Washington, D. C. 20555 Gentlemen:

VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNITS 1 AND 2 MONTHLY OPERATING REPORT Serial No.96-354 NO/RPC:vlh Docket Nos. 50-280 50-281 License Nos. DPR-32 DPR-37 Enclosed is the Monthly Operating Report for Surry Power Station Units 1 and 2 for the month of June 1996. Very truly yours, M. L. Bowling, Manager Nuclear Licensing

& Operations Support Enclosure cc: U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, N. W. Suite 2900 Atlanta, Georgia 30323 Mr. M. W. Branch NRG Senior Resident Inspector Surry Power Station 9607190023 960630 -----~ PDR ADOCK 05000280 1 R PDR I I

' -*** ' -r: **--* e e VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION MONTHLY OPERATING REPORT REPORT No. 96-06 Approved:

Station Manager Date e TABLE OF CONTENTS Section e Surry Monthly Operating Report No. 96-06 Page 2 of 18 Page Operating Data Report -Unit No. 1 ............................................................................................................................

3 Operating Data Report-Unit No. 2 ............................................................................................................................

4 Unit Shutdowns and Power Reductions

-Unit No. 1 ..................................................................................................

5 Unit Shutdowns and Power Reductions

-Unit No. 2 ..................................................................................................

6 Average Daily Unit Power Level -Unit No. 1 .............................................................................................................

7 Average Daily Unit Power Level -Unit No. 2 .............................................................................................................

8 Summary of Operating Experience

-Unit No. 1 .........................................................................................................

9 Summary of Operating Experience

-Unit No. 2 .........................................................................................................

9 Facility Changes That Did Not Require NRG Approval ............................................................................................

10 Procedure or Method of Operation Changes That Did Not Require NRG Approval .................................................

14 Tests and Experiments That Did Not Require NRG Approval ..................................................................................

15 Chemistry Report .....................................................................................................................................................

16 Fuel Handling -Unit No. 1 ...................................................................... " ................................................................

17 Fuel Handling -Unit No. 2 ........................................................................................................................................

17 Description of Periodic Test(s) Which Were Not Completed Within the Time Limits Specified in Technical Specifications

.......................................................................................................................

18 e OPERATING DATA REPORT 1. Unit Name: .......................................................... . 2. Reporting Period: ................................................ . 3. Licensed Thermal Power (MWt): ......................... . 4. Nameplate Rating (Gross MWe): ........................ . 5. Design Electrical Rating (Net MWe): ................... . 6. Maximum Dependable Capacity (Gross MWe): .. . 7. Maximum Dependable Capacity (Net MWe): ..... .. Surry Unit 1 June, 1996 2546 847.5 788 840 801 e Surry Monthly Operating Report No. 96-06 Page 3 of 18 Docket No.: Date: Completed By: Telephone:

50-280 7-02-96 D. Mason (804) 365-2459 8. If Changes Occur in Capacity Ratings (Items Number 3 Through 7) Since Last Report, Give Reasons: 9. Power Level To Which Restricted, If Any (Net MWe): 10. Reasons For Restrictions, If Any: This Month YTD Cumulative

11. Hours In Reporting Period ...............................

720.0 4367.0 206207.0 12. Number of Hours Reactor Was Critical ...........

720.0 4367.0 142417.7 13. Reactor Reserve Shutdown Hours ..................

0.0 0.0 3774.5 14. Hours Generator On-Line ................................

720.0 4367.0 140114.0 15. Unit Reserve Shutdown Hours ........................

0.0 0.0 3736.2 16. Gross Thermal Energy Generated (MWH) ...... 1792180.3 11062288.6 327 460081.1 17. Gross Electrical Energy Generated (MWH) ..... 588250.0 3686575.0 107263758.0

18. Net Electrical Energy Generated (MWH) .........

563528.0 3561696.0 102017669.0

19. Unit Service Factor ..........................................

100.0% 100.0% 67.9 20. Unit Availability Factor .....................................

100.0% 100.0% 69.8 21. Unit Capacity Factor (Using MDC Net) ............

97.7% 101.8% 63.7 22. Unit Capacity Factor (Using DER Net) ............

99.3% 103.5% 62.8 23. Unit Forced Outage Rate ................................

0.0% 0.0% 15.6 24. Shutdowns Scheduled Over Next 6 Months (Type, Date, and Duration of Each): None 25. If Shut Down at End of Report Period, Estimated Date of Start-up:

N/A 26. Unit In Test Status (Prior to Commercial Operation):

FORECAST ACHIEVED INITIAL CRITICALITY INITIAL ELECTRICITY COMMERCIAL OPERATION e OPERATING DATA REPORT 1. Unit Name: .......................................................... . 2. Reporting Period: ...............................................

.. 3. Licensed Thermal Power (MWt): ........................

.. 4. Nameplate Rating (Gross MWe): ........................ . 5. Design Electrical Rating (Net MWe): ................... . 6. Maximum Dependable Capacity (Gross MWe): ... 7. Maximum Dependable Capacity (Net MWe): ....... Surry Unit 2 June, 1996 2546 847.5 788 840 801 e Surry Monthly Operating Report No. 96-06 Page 4 of 18 Docket No.: Date: Completed By: Telephone:

50-281 7-02-96 D. Mason (804) 365-2459 8. If Changes Occur in Capacity Ratings (Items Number 3 Through 7) Since Last Report, Give Reasons: 9 .. Power Level To Which Restricted, If Any (Net MWe): 10. Reasons For Restrictions, If Any: . This Month 11. Hours In Reporting Period ...............................

720.0 12. Number of Hours Reactor Was Critical ...........

565.1 13. Reactor Reserve Shutdown Hours ..................

0.0 14. Hours Generator On-Line ................................

554.7 15. Unit Reserve Shutdown Hours ........................

0.0 16. Gross Thermal Energy Generated (MWH) ...... 1346304.5

17. Gross Electrical Energy Generated (MWH) ..... 443280.0 18. Net Electrical Energy Generated (MWH) .........

427430.0 19. Unit Service Factor ..........................................

77.0% 20.

• Unit Availability Factor .....................................

77.0% 21. Unit Capacity Factor (Using MDC Net) ............

74.1% 22. Unit Capacity Factor (Using DER Net) ............

75.3% 23. Unit Forced Outage Rate ................................

0.0% YTD Cumulative 4367.0 203087.0 3431.6 138934.5 0.0 328.1 3413.7 136969.8 0.0 0.0 8549972.3 321085026.3 2843095.0 104998739.0 2750744.0 99861159.0 78.2% 67.4% 78.2% 67.4% 78.6% 63.0% 79.9% 62.4% 2.6% 12.8% 24. Shutdowns Scheduled Over Next 6 Months (Type, Date, and Duration of Each): None 25. If Shut Down at End of Report Period, Estimated Date of Start-up:

26. Unit In Test Status (Prior to Commercial Operation):

FORECAST INITIAL CRITICALITY INITIAL ELECTRICITY COMMERCIAL OPERATION N/A ACHIEVED e UNIT SHUTDOWN AND POWER REDUCTION (EQUAL To OR GREATER THAN 20%) REPORT MONTH: June, 1996 e Surry Monthly Operating Report No. 96-06 Page 5 of 18 Docket No.: 50-280 Unit Name: Surry Unit 1 Date: 7-02-96 Completed by: Craig Olsen (1) Date Type 960607 F 960611 F (1) F: Forced S: Scheduled (2) (3) Method Duration of LER Hours N/A N/A Reason A A (2) REASON: Shutting No. Down Rx N/A N/A N/A N/A A -Equipment Failure (Explain)

B Maintenance or Test C Refueling D Regulatory Restriction (4) System Code KO JC Telephone:

(804) 365-2155 *. (5) Component Cause & Corrective Action to Code SG RLY Prevent Recurrence Entry into secondary chemistry Action Level II. Restored satisfactory secondary chemistry.

Failed relay rendered "A" reactor trip breaker inoperable.

Replaced relay. (3) METHOD: 1 -Manual 2 -Manual Scram 3 -Automatic Scram 4 -Other (Explain)

E Operator Training & Licensing Examination F Administrative G Operational Error (Explain)

(4) Exhibit G -Instructions for Preparation of Data Entry Sheets for Licensee Event Report (LER) File (NUREG 0161) (5) Exhibit 1 -Same Source L .,,...,, l *I '*-.A (1) Date Type 960606 F (1) F: Forced S: Scheduled (4) e UNIT SHUTDOWN AND POWER REDUCTION (EQUAL To OR GREATER THAN 20%) REPORT MONTH: June, 1996 e Surry Monthly Operating Report No. 96-06 Page 6 of 18 Docket No.: 50-281 Unit Name: Surry Unit 2 Date: 7-02-96 Completed by: Craig Olsen Telephone:

(804) 365-2155 (2) (3) (4) (5) Method Duration of LER No. System Component Cause & Corrective Action to Hours N/A Reason A (2) REASON: Shutting Down Rx 3 50-281/ 96-004-00 A -Equipment Failure (Explain)

B Maintenance or Test C Refueling D Regulatory Restriction Code SJ Code Prevent Recurrence SG Hi-Hi level in the "B" steam generator resulting from feedwater flow oscillations.

(3) METHOD: 1 -Manual 2 -Manual Scram 3 -Automatic Scram 4 -Other (Explain)

E Operator Training & Licensing Examination F Administrative G Operational Error (Explain)

(5) Exhibit G -Instructions for Preparation of Data Entry Sheets for Licensee Event Report (LER) File (NUREG 0161) Exhibit 1 -Same Source MONTH: June, 1996 Day 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 INSTRUCTIONS e e Surry Monthly Operating Report No. 96-06 Page 7 of 18 AVERAGE DAILY UNIT POWER LEVEL Average Daily Power Level (MWe -Net) Day 803 17 796 18 791 19 797 20 809 21 804 22 512 23 501 24 813 25 814 26 771 27 798 28 800 29 805 30 804 806 Docket No.: 50-280 Unit Name: Surry Unit 1 Date: 7-01-96 Completed by: Barry C. Bryant Telephone:

(804) 365-2786 Average Daily Power Level (MWe -Net) 806 806 805 804 803 803 805 803 798 804 803 804 806 809 On this format, list the average daily unit power level in MWe -Net for each day in the reporting month. Compute to the nearest whole megawatt.

i.~.....-'

JI '*-* MONTH: June, 1996 Day 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 INSTRUCTIONS

• e Surry Monthly Operating Report No. 96-06 Page 8 of 18 AVERAGE DAILY UNIT POWER LEVEL Average Daily Power Level (MWe -Net) Day 0 17 0 18 0 19 0 20 0 21 0 22 11 23 217 24 560 25 808 26 820 27 817 28 816 29 804 30 813 815 Docket No.: 50-281 Unit Name: Surry Unit 2 Date: 7-01-96 Completed by: Barry C. Bryant Telephone:

(804) 365-2786 Average Daily Power Level (MWe -Net) 814 814 811 811 810 806 807 808 813 811 808 793 812 809 On this format, list the average daily unit power level in MWe -Net for each day in the reporting month. Compute to the nearest whole megawatt.

e

SUMMARY

OF OPERATING EXPERIENCE MONTH/YEAR:

June, 1996 e Surry Monthly Operating Report No. 96-06 Page 9 of 18 The following chronological sequence by unit is a summary of operating experiences for this month which required load reductions or resulted in significant non-load related incidents.

UNJTONE: 6/01/96 6/07/96 6/08/96 6/11/96 6/30/96 UNIT Two: 6/01/96 6/05/96 6/06/96 6/07/96 6/08/96 6/10/96 6/28/96 6/30/96 0000 1118 The reporting period began with the unit operating at 100% power, 850 MWe. Started power reduction due to entry into secondary chemistry Action Level II. 1445 Stopped power reduction at 30%, 160 MWe. 0712 1838 1020 Started power increase following restoration of satisfactory secondary chemistry.

Stopped power increase at 100%, 850 MWe. Started power reduction due to inoperable "A" reactor trip breaker (6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> LCO). 1256 Stopped power reduction at 58%, 485 MWe. 1326 Started power increase after returning "A" trip breaker to operable status. 1539 Stopped power increase at 100%. 2400 0000 1756 2344 1053 The reporting period ended with the unit operating at 100% power, 850 MWe. The reporting period began with the unit at refueling shutdown.

Reactor critical.

Reactor automatically tripped from 16% power due to Hi-Hi level in the "B" steam generator.

Reactor critical.

2134 Generator on line. Started power increase.

2325 Stopped power increase at 29%, 200 MWe to perform flux mapping. 1248 0410 1130 Started power increase.

Stopped power increase at 100%, 850 MWe. Started power reduction to maintain condenser vacuum while "B" waterbox was removed from service. 1216 Stopped power reduction at 95%, 780 MWe. 1528 Started power increase.

1640 Stopped power increase at 100%, 850 MWe. 2400 The reporting period ended with the unit operating at 100% power, 850 MWe.

'.; r.

• DCP 96-015 DCP 95-030 DCP 94-073 e FACILITY CHANGES THAT DID NOT REQUIRE NRC APPROVAL MONTHNEAR:

June, 1996 Design Change Package (Safety Evaluation No.96-051) e Surry Monthly Operating Report No. 96-06 Page 10 of 18 5-10-96 Design Change Package 95-030 replaced approximately 15 feet of Unit 2 residual heat removal (RHR) system pipe, 6"-RH-120-152, and installed a new outside containment isolation valve adjacent to containment penetration No. 24. The existing schedule 1 OS piping was replaced to correct degradation that had been identified by ultrasonic testing. The schedule 40 replacement piping and new containment isolation valve increased the structural integrity and seismic adequacy of the line. The modifications did not affect the design or operation of the RHR system, or the margin of safety as defined in the Jechnical_Specifications.

Therefore, an unreviewed safety question does not exist. Design Change Package (Safety Evaluation No.95-126) 5-17-96 Design Change Package 95-030 replaced the motor operators of Units 1 and 2 safety injection (SI) system motor operated valves (MOV), 1-SI-MOV-1860A[B]

and 2-SI-MOV-2860A[B]

with larger, similarly designed motor operators to ensure the affected valves will perform their intended function under postulated system conditions.

The replacement motor operators provide additional capacity margin, but do not change the valve function or impact the system design basis. Therefore, an unreviewed safety question does not exist. Design Change Package (Safety Evaluation No. 95-085A) 5-22-96 Design Change Package 94-073 revised the timing associated with the energization of the lift, moveable gripper, and stationary gripper coils of the Units 1 and 2 rod control systems. The timing changes were implemented consistent with the Westinghouse Owner's Group recommendations for addressing Generic Letter 93-04. Post implementation testing was performed to ensure the timing modifications perform properly.

The changes enhance the reliability of the rod control system and do not affect the margin of safety as defined in the Bases to any Technical Specification.

Therefore, an unreviewed safety question does not exist.

DCP 94-047 DCP 91-045 JCO S2-96-002 WO 00342881 02 e FACILITY CHANGES THAT DID NOT REQUIRE NRC APPROVAL MONTHNEAR:

June, 1996 Design Change Package (Safety Evaluation No.96-029) e Surry Monthly Operating Report No. 96-06 Page 11 of 18 5-25-96 Design Change Package 94-047 replaced the existing Unit 2 steam generator blowdown coolers and added an independent divert line to enable the coolers' condensate flow to be returned to the main condenser.

The new coolers utilize stainless steel tubes which eliminate the copper carryover to the steam generators that was associated with the previous equipment.

The modifications conform to the appropriate codes and standards and enhance the cooling capacity of the system. The modifications did not involve or impact any safety-related equipment or systems. Therefore, an unreviewed safety question does not exist. Design Change Package 5-27-96 Design Change Package 91-045 replaced Unit 2 recirculating spray heat exchanger service water check valves and the pipe flanges from the affected lines with a pipe spool welded in place. The DCP also applied an epoxy coating to 24 inch and larger service water (SW) system piping to protect against the formation of rust/corrosion.

The modifications improved the integrity of the SW system by removing nonfunctional valve bodies and corroded bolted flanges The design, operation, function, or configuration of the SW system was not affected.

Therefore, an unreviewed safety question does not exist. Justification For Continued Operation (Safety Evaluation No.96-084, Revision 1) 6-04-96 Justification For Continued Operation S2-96-002 assessed the acceptability of Unit 2 operation with Main Control Room annunciator panels "A" through "E" or "F" through "K" (alternately) removed from service during the inspection/replacement of annunciator system power supplies . . The subject panels are non-safety related and do not affect protection circuits.

Compensatory actions include the use of alternate indications and increased monitoring of affected plant parameters by additional control room operators.

The assessment concluded that operation of Unit 2 is acceptable during the subject inspection/replacement activity.

Therefore, an unreviewed safety question does not exist. Work Order 6-05-96 (Safety Evaluation No.96-085) Work Order 00342881 02 performed an on-line temporary leak-seal repair of Unit 2 Reactor Coolant System valve 2-RC-77. The valve was sealed in the open (normal) position to eliminate system leakage past the valve packing. An evaluation of this activity concluded that the leak sealant material will not affect the pressure boundary, structural integrity, pressure rating, or temperature rating of the subject valve. Therefore, an unreviewed safety question does not exist.

TM S1-96-12 TM S1-96-13 TM S2-96-017 DCP 92-043 e FACILITY CHANGES THAT DID NOT REQUIRE NRC APPROVAL MONTHNEAR:

June, 1996 Temporary Modification

.(Safety Evaluation No.96-086)

• Surry Monthly Operating Report No. 96-06 Page 12 of 18 6-08-96 Temporary Modification (TM) S1-96-12 installed a temporary skid mounted chiller to perform the function of the Unit 1 chemical monitoring chiller until it is repaired or replaced.

The TM restored the capabilities of the non-safety related on-line chemistry monitoring system. The TM did not affect other systems. Therefore, an unreviewed safety question does not exist. Temporary Modification (Safety Evaluation No.96-087) 6-11-96 Temporary Modification (TM) S1-96-13 installed electrical jumpers to maintain Unit 1 Reactor Protection System (RPS) train "A" and turbine trip circuitry operable during the replacement of relay 1-RP-RL Y-TTXA. The activity did not affect RPS train "B". Double verification of the installation/removal of the TMs and post-maintenance testing was performed.

Therefore, an unreviewed safety question does not exist. Temporary Modification (Safety Evaluation No.96-088) 6-19-96 Temporary Modification (TM) S2-96-017 installed a temporary strip chart recorder to provide more precise and continuous monitoring of the Unit 2 pressurizer safety valve acoustic monitors.

The TM does not affect the acoustic monitoring system and alarm indication.,.

The TM does not impact any automatic protection or control functions.

Therefore, an unreviewed safety question does not exist. Design Change Package (Safety Evaluation No.93-176) 6-20-96 Design Change Package 92-043 replaced the Unit 2 pressurizer safety valves (PSVs), replaced/rerouted the PSV and power operated relief valve (PORV) loop seal drain lines, and replaced the existing reflective metal insulation on the PSV loop seals with stainless steel jacketed fiberglass insulation.

The new PSVs are designed to seal tighter under pressurizer steam conditions and discharge piping loads. The new drain lines will allow the PSV and PORV loop seals to drain continuously which will significantly reduce the hydraulic forces experienced by the discharge piping during valve actuation.

The subject modifications were implemented in accordance with the system design criteria and did not affect the capability of the PSVs or PORVs to perform their safety function.

Therefore, an unreviewed safety question does not exist.

WO 00342976 01 FS 95-38 FS 95-45 Work Order FACILITY CHANGES THAT DID NOT REQUIRE NRC APPROVAL MONTHNEAR:

June, 1996 (Safety Evaluation No.96-089) -Surry Monthly Operating Report No. 96-06 Page 13 of 18 6-26-96 Work Order 00342976 01 removed Unit 2 annunciator panels "A" through "D" from service to allow the improper operation of annunciator 2G-B7, "SHLD TK SURGE TK HI-LO LVL," to be investigated and repaired.

The subject panels are non-safety related and do not affect protection circuits.

Compensatory actions include the use of alternate indications and increased monitoring of affected plant parameters by additional control room operators.

The assessment concluded that operation of Unit 2 is acceptable during the subject inspection/replacement activity.

Therefore, an unreviewed safety question does not exist. Updated Final Safety Analysis Report Change (Safety Evaluation 96-090) 6-27-96 Updated Final Safety Analysis Report Change 95-38 revised Section 2.3, "Hydrology," to reflect updated historical hydrologic data, the most recent results of the 1 DO-year storm flow rate calculation, and the current number of shallow wells in the vicinity of the station. These changes were administrative in nature. No physical or procedural changes affecting any structure, system, or component were involved.

Therefore, an unreviewed safety question does not exist. Updated Final Safety Analysis Report Change (Safety Evaluation 96-091) 6-27-96 Updated Final Safety Analysis Report Change 95-45 revised Section 15.3.2, "Reinforcing Steel," to reflect industry advancement in the availability and use of reinforcing steel that is stronger than Grade 40. This change was administrative in nature. No physical or procedural changes affecting any structure, system, or component were involved.

Therefore, an unreviewed safety question does not exist.

e Surry Monthly Operating Report No. 96-06 Page 14 of 18 PROCEDURE OR METHOD OF OPERATION CHANGES THAT DID Nor REQUIRE NRC APPROVAL MONTH/YEAR:

June, 1996 None During the Reporting Period

• • ,J * *, ** e Surry Monthly Operating Report No. 96-06 Page 15 of 18 TESTS AND EXPERIMENTS THAT DID Nor REQUIRE NRC APPROVAL MONTHNEAR:

June, 1996 None During the Reporting Period e Primary Coolant Analysis Gross Radioactivity, µCi/ml Suspended Solids, ppm Gross Tritium, µCi/ml 1131, µCi/ml 113111133 Hydrogen, cc/kg Lithium, ppm Boron -10, ppm* Oxygen, (DO), ppm Chloride, ppm pH at 25 degree Celsius

• Boron -1 O = Total Boron x 0.196 Comments:

None CHEMISTRY REPORT MONTH/YEAR:June, 1996 Unit No. 1 Max. Min. Avg. 1.09E+O 2.36E-1 7.57E-1 . ::::;0.01

0.01

0.01 8.08E-1 5.69E-1 6.51E-1 6.66E-2 2.65E-3 1.22E-2 0.85 0.34 0.56 38.9 34.9 36.2 2.33 1.95 2.18 167.0 133.5 143.5

:::;0.005

0.005

0.005

0.050 0.003 0.006 6.93 6.38 6.55

• Surry Monthly Operating Report Max. 1.93E-1 0.250 2.42E-1 7.65E-4 0.19 38.5 3.72 456.9 0.2 ::::;0.050 6.32 Unit No. 2 Min. 1.23E-3 ::::;0.01 6.19E-2 1.84E-5 0.05 5.5 0.12 260.5 ::::;0.005 0.002 4.84 No. 96-06 Page 16 of 18 Avg. 9.17E-2 0.11 1.51 E-1 3.63E-5 0.11 25.1 2.21 349.0 0.018 0.006 5.86

• ... ** "*-~ New or Spent Fuel Shipment Date Stored or Number Received e FUEL HANDLING UNITS 1 & 2 MONTHNEAR:

June, 1996 Number of Assemblies per Shipment Assembly Number ANSI Number e Surry Monthly Operating Report No. 96-06 Page 17 of 18 Initial Enrichment New or Spent Fuel Shipping Cask Activity No Fuel Received or Stored During the Reporting Period I', '/ ... e e Surry Monthly Operating Report No. 96-06 Page 18 of 18 DESCRIPTION OF PERIODIC TEST(S) WHICH WERE NOT COMPLETED WITHIN THE TIME LIMITS SPECIFIED IN TECHNICAL SPECIFICATIONS MONTHIYEAR:June, 1996 -None During the Reporting Period