IR 05000237/1981016
| ML17193B532 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 06/25/1981 |
| From: | Jackiw I, Robinson D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML17193B531 | List: |
| References | |
| 50-237-81-16, NUDOCS 8107150061 | |
| Download: ML17193B532 (6) | |
Text
U.S. NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT
REGION III
Report No. 50-237/81-16 Docket No. 50-237 Licensee:
Commonwealth Edison Company P, 0. Box 767 Chicago, IL 60690 Facility Name:
Dresden Nuclear Power Station, Unit 2 Inspection At:
Morris, Illinois Inspection C~ducted: May 14, and
~~~-~
Inspectors:
\\ l.~~obinson ~
Approved By: *
~.. ~ N. J w, Acting Test Pr m Section Inspection Summary June 9-10, 1981 Chief License No. DPR-19
I Inspection on May 14, June 9, 10, 1981.(Report No. 50-237/81-16)
Areas Inspected:
Routine, announced inspection of startup test procedures; control rod drive scram time tests; control rod sequence and reactivity checks; moderator temperature coefficient measurement; core power distri-bution limits; LPRM calibrations;.Af>RM calibrations; core thermal power evaluation; determination of reactor shutdown margin; determination of reactivity anomalies; safety/relief valve discharge test The inspection involved 20 inspector-hours onsite by two NRC inspectors including two inspector-hours during offshift Results:
No items of noncompliance or deviations were identifie ( 8107150061 810702
\\ \\
l l_ ~~R-~~-~~~-o_s_o_o __
o~_g_~_J _[ __ J
.
c DETAILS Persons Contacted
- D. Scott, Station Superintendent
- J. Brunner, Station Technical Staff Supervisor J. Wojnarowski, Lead Nuclear Engineer
- D. Long, Nuclear Engineer L. Rippy, Unit 2 Nuclear Engineer
- D. Maxwell, Associate Engineer P. Holland, Nuclear Technician
- E. Wilmere, QA Coordinator T. Tongue, NRC Senior Resident Inspector
- M. Jordan, NRC Resident Inspector
- Denotes those present during the exit intervie.
Verification of Conduct of Startup Physics Testing The inspector reviewed the startup physics testing and verified that the licensee conducted the following: Control Rod Scram Time Tests Control Rod Sequence and Reactivity Checks c~
Moderator Temperature Coefficient Measurement LPRM Calibration APRM Calibration Core Thermal Power Evaluation Determination of Reactor Shutdown Margin Determination of Reactivity Anomalies Control Rod Drive Scram Time Tests The inspector reviewed information relating to the Dresden 2 Cycle 8 control rod drive scram time tests as. described in DTS 300-2, Control Rod Drive Scram Testing and Scram Valve Timing Test", Revision 5, dated April 15, 1980 and the results of those tests conducted on April 25-26, 198 The inspector noted that the accumulator pressures for the West CRD bank were not recorded as required by procedur Upon questioning, the licensee stated that the pressures had been recorded by the B man in the Reactor Building, but that his copy had apparently been misplace This problem with record control resulted in a commitment by the licensee to rewrite the procedure such that the accumulator pressures would be recorded in the control room and not in the reactor buildin As the licensee had already committed to a retest, the inspector was satisfied with the resolution of the issu **
The scram time tests on April 25-26, 1981, were conducted with the reactor in a cold condition in apparent conflict with Technical Speci-fication requirements and current industry practic After discussions with the resident inspectors who identified the problem, the licensee redid the tests on June 1-4, 1981 at a reactor pressure of 957 psi The inspector reviewed the data and verified that the scram insertion times met Technical Specification requirements as shown below:
% Inserted From Fully Withdrawn
20 so
Maximum TS Average Insertion Time (Sec.)
0.375 0.900 2.000 3.500 Actual Average Insertion Time (Sec.)
0.329 0. 722 1.500 2.600 Also, a check of all 2 x 2 arrays revealed that the average of the three fastest control rods in each of those arrays met Technical Specification limit The issue of whether the scram time tests should be conducted under cold or hot conditions is at present an unresolved item and will be*
tracked by the resident inspector Report No. 50-237/81-1 No items of noncompliance or deviations were. identifie.
Control Rod Sequence and Reactivity Checks The inspector reviewed information relating to the Dresden 2 Cycle 8 control rod sequence and reactivity checks as described in SP-ROD,
"Special Control Rod Sequence Package, Unit 2, Cycle 8", Revision O, dated May 14, 1981 and DTS 8154, "Control Rod Following and LPRM Operability Verification", Revision 1, dated March 31, 197 The inspector observed the test performance on May 14, 1981 and verified that all applicable Technical Specifica~ion requirements were me No items of noncompliance or deviations were identifie.
Moderator Temperature Coefficient Measurement The inspector reviewed information relating to Dresden 2 Cycle 8 measurement of the moderator temperature coefficient (MTC) as described in DTS 8137, "Moderator Temperature Coefficient of Reactivity", Revision 1, dated March 31, 197 The inspector noted that the procedure requires MTC measurement at no less than'three reference temperature covering the reactor moderator operating temperature range (90°F to 540°F) with emphasis on ihe lower temperatures, whose coefficient is less negativ Measurements were taken on May 10, 1981 under heatup conditions yielding MTC values ranging from -3.9 pcm at 172°F to -4.6 pcm at 248° Attempts to take MTC measurements at higher temperatures proved unsuccessful as the necessary rod pulls resulted in unacceptably short reactor period \\
... _,i,-1 I>
- No items of noncompliance or deviations were identified.
Core Power Distribution Limits The inspector examined selected printouts of the periodic and the on-demand computer program following the Dresden 2 Cycle 8 startup in May, 1981 with attention focused on the May 22, 1981 data when the plant was operating at 94.3% rated power, its maximum value thus far in the cycl The inspector determined that all prerequisites were met, the GE process computer was using input values from the actual plant conditions, and all thermal margins satisfied Technical Specifi-cation requirement No items of noncompliance or deviations were identifie.
LPRM Calibrations The inspector reviewed information relating to Dresden 2 Cycle 8 LPRM calibration as described in DTS 8232, "Whole Core LPRM Calibra-tion", Revision 2, dated October 8, 198 The inspector verified that a whole core LPRM calibration was performed on May 13, 1981 at 63.9% rated power and concluded that the licensee had satisfied the vendor's recommendation that LPRMs be calibrated every 1000 effective full power hour No items of noncompliance or deviations were identifie APRM Calibrations The inspector reviewed information relating to the Dresden 2 Cycle 8 APRM calibration as described in DTS 8139, "APRM calibration, Revi-sion 2, dated April 13, 198 The inspector verified that an APRM calibration was performed on May 13, 1981 following a whole core LPRM calibration that same da No items of noncompliance or deviations were identifie.
Core Thermal Power Evaluation The inspector reviewed information relating to Dresden 2 Cycle 8 core thermal power evaluation as described in DTS 8237, "Calculation of Core Thermal Power - Technical Staff Method", Revision 2, dated March 31, 198 The inspector noted that the procedure was used in conjunction with the APRM calibration on May 13, 198 A comparison of the hand calculation with an OD-3 edit produced agreement within 2% and the inspector concluded that the procedure was technically adequat *
No items of noncompliance or deviations were identified.
- 4 -
10.
Determination of Reactor Shutdown Margin The inspector reviewed information relating to the Dresden 2 Cycle 8 determination of reactor shutdown margin as described in DTS 8134,
"Units 2/3 Shutdown Margin Demonstration", Revision 7, dated April 10, 198 The Technical Specifications require that following a refueling outage core loading be limited such that it can be made subcritical with a minimum margin of 0.25%AK at any time in the subsequent fuel cycle with the strongest operable control rod fully withdrawn and all other operable rods fully inserte The inspector noted that the shutdown margin over Cycle 8 is not a minimum at beginning of cycle (BOC) but occurs at approximately 4,000 Mwd/t into the cycl As a result, a shutdown margin at BOC of 0. 00254 K + "R" should be demonstrated, where R = 0. 0082..Q. Kis the difference between BOC shutdown margin and minimum shutdown margi The inspector reviewed the results of the two rod diagonally adjacent subcritical and the in-sequence critical shutdown margin tests performed on May 9, 1981 and concluded that they met the Technical. Specification The total shutdown margin at BOC with a recirculation loop temperature of 161.8°F was found to be 3.57%AK compared to that predicted by General Electric of 3.33%AK for a moderator temperature of 68° No items of noncompliance or deviations were identifie.
Determination of Reactivity Anomalies The inspector reviewed information relating to the Dresden 2 Cycle 8 determination of reactivity anomalies as described in DTS 8631,
"Reactivity Anomaly Calculation", Revision 5,.dated March 25, 198 The Technical Specifications require that the reactivity equivalent of the difference between the actual rod configuration and the exp"ected configuration during power operation shall not exceed 1%.6.K, and a comparison will be made at least once every equivalent full power mont The inspector verified that the calculated difference between the actual rod configuration and the predicted one was within the lower 1%~K anomaly band and was performed at least once every equivalent full power month in acc~rdance with the Technical Specification No items of noncompliance or deviations were identifie.
Safety Relief Valve Discharge Test On May 14, 1981 the licensee conducted safety/relief valve discharge tests to measure the structural response of the containment to SRV discharge hydrodynamic load Data obtained from the test will be used to verify the design adequacy of the containment and related structure Anticipated completion of the test program and issuance of the final report is expected sometime in August, 198 \\
Q~;.-~
.c
~..
The inspector verified that the SRV test was conducted in accordance with approved procedures that included:
prerequisites, precautions, limitations and action, acceptance criteria, checkoff lists, and provision for identification of personnel conducting the tes The inspector noted that initial data obtained during the test indicated that the readings were within the expected values and no abnormal vibrations were observed during a tour of the torus are No items of noncompliance or deviations were identifie.
Exit Interview The inspector met with the licensee representatives (denoted in Paragraph 1) at the conclusion of the inspection on June 10, 198 The inspector summarized the purpose and the scope of the inspection and the finding