IR 05000237/1979011
| ML17173A936 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 05/03/1979 |
| From: | Dettenmeier R, Reyes L, Streeter J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML17173A935 | List: |
| References | |
| 50-237-79-11, 50-249-79-09, 50-249-79-9, NUDOCS 7906260633 | |
| Download: ML17173A936 (6) | |
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U.S. NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT
REGION III
Report No. 50-237/79-11; 50-249/79-09 Docket No. 50-237; 50-249 Licensee:
Commonwealth Edison Company Post Office Box 767 Chicago, IL 60690 License No. DPR-19; DPR-25 Facility Name:
Dresden Nuclear Power Station, Units 2 and 3 Inspection At:
Dresden Site, Morris, IL Inspection Conducted:
March 27, April 13, 21-23 and 27, 1979
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J. F. Str eter, Chief Nuclear Support Section 1 Inspection Summary Inspection on March 27, April 13, 21-23 and 27, 1979, (Report N /79-11; 50-249/79-09)
Areas Inspected:
Routine, unannounced inspection of the performance of the Unit 2 integrated leak rate test and licensee action on a pre-viously identified item of noncompliance (Unit 3).
The inspection involved 53 inspector-hours onsite by two NRC inspectors and one NRC
inter Results:
No items of noncompliance or deviations were identified during this inspection.
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DETAILS Persons Contacted.
- R. Ragan, Operating Engineer
- D. Farrar, Technical Staff Supervisor
- B. Shelton, Administrative Assistant
- R. Geier, Quality Assurance
- R. Kyrouhd, Technical Staff Engineer
- J. Achterberg, Technical Staff Engineer
- G. Smith, Technical Staff Engineer
- M. Wright, Technical Staff Engineer
- A. Roberts, Technical Staff Engineer The inspectors also talked with and interviewed several members of the Engineering, Operating and Technical Staff *Denotes those present at the exit interview on April 27, 197 Previous Inspection Findings (Closed) Noncompliance (Item 1 IE Report 50-249/78-12):
Failure to document a change to the computer model used in the Unit 3 containment leak rate tes The inspector reviewed the revised CILRT procedure which provides instructions to the test director to document any changes to the computer model in the CILRT Log after conducting a review at the same level of review given to other normal temporary procedure change The inspector verified that a simplified flow diagram of the computer program and a diagram of sensor location was available during the CILR The licensee's corrective actions were acceptabl Containment Integrated Leak Rate Test (CILRT)
The 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> CILRT was started on April 23, 1979, at 091 The inspector independently evaluated leak rate data to verify the licensee's calculation of the leak rat There was acceptable agreement between the inspector's and licensee's leak rate calculations as indicated in the following summary (units are in weight percent per day):
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Measurement Leakage rate measured (Lam)
during CILRT Lam at 95% confidence level Lam at 95% confidence level adjusted to reflect penalties (ref er to Paragraph 8) due to use of shutdown cooling and valve line up deviation Licensee Inspector 0.2515 0.2516 0.2592 0.2593 0.3953 0.3954 Appendix J Acceptance Criterion at 95% confidence level= 0.75 La
= 0.75 (1.6) = As indicated above, the adjusted Lam at the 95% confidence level was less than the maximum allowable by 10 CFR Part 50, Appendix No items of noncompliance or deviations were identifie Supplemental Test After the satisfactory completion of the 24-hour test on April 23, 1979, a known leakage of 0.2515 weight percent/day was induce The inspector independently evaluated leak rate data to verify the licensee's calculation of the supplemental leak rat There was acceptable agreement between the inspector's and licensee's leak rate calculations as indicated in the following sunnnary (units are in weight per~errt per day):
Measurement Licensee Inspector Measured leakage (Le) rate 0.4530 0.4529 during supplemental test Le @ 95% confidence level 0.5054 0.5053 Induced leakage rate (Lo)
0.2515 0.2515
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Appendix J Acceptance Criterion:
Lo+Lam-0. 25La L Le L Lo+Lam+0.25La 0. 2515+0. 2516-0. 4 L Le L 0. 2515+0. 2516+0. 4 O. 1031 L Le LO. 9031 As indicated above, the supplemental test results satisfied the requirements of 10 CFR Part 50, Appendix No items of noncompliance or deviations were identifie.
Instrumentation The inspector reviewed the calibration data associated with per-forming the CILR A multipoint calibration of all instrumen-tation was performe Correction values were generated based on the difference between measurements of resistance from a NBS verifjed resistance box and actual resistance measure All corrections were placed as an array or equation into the CILRT compute The following instrumentation was used in the CILR Type Quantity Serial Number RTDs
5377-1 thru 29, 30A, Flowmeter
VMC 801/714 Pressure Gauge
1087' 1088 Dewcells
5377-1, 2 and 4-9 No items of noncompliance or deviations were identifie.
CILRT Procedure Review The inspector reviewed a copy of procedure DTS 1600-7, Revision 2
"Unit 2/3 Integrated Primary Containment Leak Rate Test," for technical adequacy and conformance with regulatory requirement The inspector has no further questions on the procedur B
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( Data Rejection The inspector stated that, during the conduct of CILRT, individual data points are sometimes erroneous for various reason The inspector also stated that these erroneous data points cannot be rejected without a definitive data rejection criteri The licensee's procedure contains no such criteri There were no data points rejected during the 1979 CILR The inspector stated that the draft ANS 274 standard contains acceptable data rejection criteri.
CILRT Valve Lineup for Pressure Switches During the 1979 CILRT the Drywell, Torus and Drywell to Torus differential pressure switches and transmitters were isolated from the containment atmospher This closes a potential leakage path that would be exposed under postaccident condition The licensee stated that the pressure switches were isolated during CILRT to prevent changes in calibration and possible unrepair damag There are no means to locally test the switches at the present tim This is an Unresolved Item (50-237/79-11-01) pending further review by the inspecto No items of noncompliance or deviations were identifie.
CILRT Valve Lineup Penalties During the test, it is essential that the shutdown cooling system be in operation to maintain stable reactor temperatur This value configuration along with others noted below deviated from the normal CILRT valve lineu As a result, the local leak rate test results are added as a penalty to Lam at the 95% confidence leve System SCFH WT%/Day
'A' FW Line 15.88 0.03242
'B' FW Line 11.22 0.02291 CRD 4. 04 0.00825 Shutdown Cooling
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Standby Liquid Control Isolation Condenser
'A' LPCI
'B' LPCI
'A' Core Spray
'B' Core Spray CAM Primary Sample Reactor Cleanup TOTAL 1. 26 1. 61 9.64 6.92 5.75 1. 15 0.78 0.02 8.36 66.63 0.00257 0.00328 0.01968 0.01413 0.01174 0.00234 0.00159 0.00004 0.01707 0.01361 Plant Tour 1.
The inspector conducted a tour of various areas of the plant to observe operations and activities in progress, general house-keeping and cleanliness, and equipment caution or lockout tag No items of noncompliance or deviations were identifie Unresolved Items Unresolved items are matters about which more information is required in order to ascertain whether they are acceptable items, items of noncompliance, or deviation An unresolved item dis-closed during the inspection is discussed in Paragraph Exit Interview An exit interview was conducted at the conclusion of the inspec-tion with the licensee representatives denoted in Paragraph The total leak rate after all corrections werP included was determined by the licensee to be 0.3953 weight percent/da "