IR 05000295/1978029
| ML19294A676 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 01/22/1979 |
| From: | Chow E, Creswell J, Streeter J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML19294A675 | List: |
| References | |
| 50-295-78-29, NUDOCS 7903080150 | |
| Download: ML19294A676 (4) | |
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U.S. NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT
REGION III
Report No. 50-295/78-29 Docket No. 50-295 License No. DPR-34 Licensee:
Commonwealth Edison Company P. O. Box 767 Chicago, IL 60690 Facility Name:
Zion Unit 1 Inspection At:
Zion Nuclear Power Station, Unit 1, Zion, Illinois Inspection Conducted: October 31, November 29-30, and December 4-5, 1978 Nmb 29-30, December 4-5, 1978)
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't Inspectors C
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'3. S. Creswell (November 29-30, December 4, 1978)
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kWW I/2,'g3 J. L. Kohler (October 31, 1978)
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Approved By:
J F. Streeter, Chief (December 5, 1978)
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Nuclear Support Section 1 Inspection Summary Inspection on October 31, November 29-30, and December 4-5, 1978 (Report No. 50-295/78-29)
Areas Inspected: Routine, unannounced inspection of core power distribution limits; isothermal temperature coefficient; control rod worth measurement; determination of reactivity anomaly; review of return of plant equipment to operations following refueling outage.
The inspection involved 41 inspector-hours onsite by four NRC inspectors.
Results: No items of noncompliance or deviations were identified.
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DETAILS 1.
Persons Contacted
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- L.
Soth, Administrative Assistant
- R. Ungeran, Assistant Technical Staff Supervisor
- M. Peterson, Station Nuclear Engineer
- J.
Gilmore, Shift Engineer
- B.
Harl, Quality Assurance Engineer
- C.
Schumann, Senior Operating Engir.eer T. Olling, Engineering Assistant W. Naughton, Nuclear Licensing Adminstrator
- denotes those present during the exit interview.
2.
Core Power Distribution Limits The inspectors examined the flux map taken at 75% power.
The being used was 2.02 in accordance with the or0e(Z) peaking factor inspectors noted that the maximum allowable F r for modification of license dated April 21, 1978, instead of the 2.235 specified in the Technical Specifications.
In addition, the normalized allowable F (Z) used was different from that in the Technical Specificati8ns. The product of the new maximum allowable F (Z)
and its related height dependent correction factor (K (Z)) was t
smaller than the product allowed by the Technical Specifications.
This verified that the calculation was still conservative.
No items of noncompliance or deviations were identified.
3.
Isothermal Temperature Coefficient of Reactivity Measurement The inspectors noted that some plots of isothermal temperature coefficient measurements showed non-linear slopes whereas other plots did show reasonably linear slopes.
It appeared that the testing conditions during the measurements needed to be more stabilized so that linear slopes could be obtained for all plots.
The licensee stated that it was very difficult to stabilize test conditions but that an effort would be made to obtain better measurements during future tests.
No items of noncompliance or deviations were identified.
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Control Rod Worth Measurement The inspectors verified that the input parameters to the Westinghouse reactivity computer were identical to those in WCAP 9356 (Core Physics. Characteristics of the Zion Station Unit 1, Cycle 4).
The inspectors examined the measured worths of four control banks and three shutdown banks.
The inspectors verified that at the beginning of life the total measured worths of all banks with minus ten percent measurement uncertainty and minus the worth of the most reactive rod satisfied the accept-ance criterion of the testing procedure.
In addition, the inspectors verified that at the end of life the total bank worth also satisfied the acceptance criterion.
No items of noncompliance or deviations were identified.
5.
Reactivity Anomaly The inspectors noted that at hot zero power (HZP), the measured critical boron concentration was higher than the predicted value, and the reactor core appeared to be over-reactive.
How-ever, at hot full power (HFP), the measured critical boron concentration was less than the predicted values and the reactor core appeared to be under-reactive.
The licensee stated that the discrepancy between the two opposite trends was mainly due to the build-up of the Doppler and the Xenon effects as the reactor power changed from HZP to HFP.
No items of noncompliance or deviations were identified.
6.
Review of Plant Operations The inspectors reviewed the information relating to the return of plant equipment to operations following the refueling outage.
The inspectors noted that the verification of the positions of some valves were not documented on the valve lineup sheets (i.e., blank signature spaces). The licensee stated that out-of-service sheets contained information on verifying the positions of the valves in question and that the licensee's administrative procedures required a review of all out-of-service sheets prior to plant startup.
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The licensee stated that although the above mentioned controls should assure proper valve positions prior to startup, a revised system of documentation was under development for more efficient and effective review of the systems disturbed or tested during a refueling outage.
No items of noncompliance or deviations were identified.
7.
Exit Interview The inspectors met with licensee representatives (denoted in Paragraph 1) at the conclusion of the inspection on December 5, 1978. The inspectors summarized the purpose, scope, and findings of the inspection.
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