IR 05000155/1979008
| ML19241C038 | |
| Person / Time | |
|---|---|
| Site: | Big Rock Point File:Consumers Energy icon.png |
| Issue date: | 05/07/1979 |
| From: | Chow E, Streeter J, Wong B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | |
| Shared Package | |
| ML19241C037 | List: |
| References | |
| 50-155-79-08, 50-155-79-8, NUDOCS 7907260300 | |
| Download: ML19241C038 (6) | |
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L'. S. Sl' CLEAR REGl'LATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT
REGION III
Report No. 50-155/79-08 Docket No. 50-135 License No. DpR-6 Licensee:
Censumers Power Company 212 West Michigan Avenue Jackson, MI 49201 Facility Name:
Big Rock Point Nuclear Plant Inspection At:
Big Rock Point Site, Charlevoix, MI Inspection Conducted:
April 17-20, 1979 k.<'
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5f 7/7 9 Inspectors:
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l Approved By J.
F. St/eeter, Chief kN 3,ly7)
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Nuclear Support Section 1 Inspection Surmary Inspection on April 17-20, 1979 (Report No. 50-155/79-08)
Areas Inspected:
Routine, unannounced inspection of coderator te ner-ature coefficient; control rod sequence and reactivity checks; control rod scrar time tests; shutdown cargi1 determination; core thermal power determination; review f plant operation.
The inspection involved 49 inspector-hours onsite by two NRC inspectors.
Results:
No itees of noncompliance or deviations were identified.
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DETAILS 1.
Persons Centacted C.
J.
Hartman, Plant Superintendent 1).
E.
DeMaor, Technical En g;in eer
- D.
BlantSard, Reactor Engineer
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Monshor, Reactor Engineer C.
F.
Sonnenberg, Shift Supervisor M. Malec, Document Control Clerk A.
Sevener, Operations Supervisor J. R. Johnson, Control Operator
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Fisher, QA Engineer
- K.
Brun, Senior Secretary
- J.
Rang, Operations - Maintenance Superintendent
- Denotes those attending the exit interview.
2.
Moderator Temperature Coefficient The inspector reviewed information relating to Cycle 15 moderator temperature coefficient test as described in orecedure No. RE-9.
Big Rock Point Technical Specifications require that the maximum amount of reactivity added when heating from ambient be less than one dollar.
The inspector reviewed Cycle 15 measirements taken on October 18, 1977.
The inspector noted that the heating started from an arbient temperature of approximately 80 F by running both recirculating pumps.
The reactor was brought supercritical by withdrawing control rods until a rising period of approximately 110 seconds was attained.
The period and the primary system temperature were recorded, and the period was converted to reactivity so that moderator temperature coefficient could be obtained.
This process was repeated using increasing temperatures until the moderator temperature coefficient became negative.
The amount of reactivity added from ambient temperature to the turnover temperature was 9.'
cents which was less than the acceptance criterion of 0.5 dc.llar.
The inspector reviewed analytical information relating to Cycle 16 determination of moderator temperature coefficient using GROK, a three-dimensional BWR simulator computer program.
The computer
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results indicated that the maximum reactivity addition due to heatup at beginning of cycle and end of cycle were 12 cents and 35 cents respectively.
The inspector concluded that the Technical Specifications require-tent on nederator temperature coefficient was satisfied for Cyc1t 15 and 16 No items of noncompliance or deviations were identified.
3.
Control Rod sequence and Reactivity Checks The inspector reviewed information relating to Cycle 15 control rod sequence and reactivity check as described in Procedure No.
16.3.2, " Critical Configuration Prediction."
The acceptance criterion stated that the difference between the predicted and the actual critical configuration be less than l' of reactivity.
The inspector examined the results on Attachment I, " Reactivity Analysis," of Procedure No. 16.3.2.
The inspector compared the actual contrel rod sequence with that estinated by GRon the comparison indicated that there was no difference between the predicted and the actual control rod pattern, and the difference between the predicted and the actual k eft _ was none.
The inspector reviewed informatiot elating to Cycle 16 Pro-alysis was perforced on cedure No. 16.3.2.
The reactivity 4 April 17, 1979.
The result indicott * that actual criticality was achieved using the predicted contt 'l rod withdrawal sequence and the reactor was critical when Rod D6 was withdrawn to Sctch
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The difference between the predicted and the actual kei f to the difference between the predicted and the actual terperature was.23: of reactivity.
The inspector concluded that Cycle 15 and Cycle 16 control rod sequence and reactivity checks were adequate.
No items of nonconpliance or deviations were identified.
Control Rod Scram Time Tests Big Rock Point Technical Specifications require that the control rod scram time be less than 2.5 seconds for 90: insertion of all control rods.
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The inspector reviewed information relative to Cycle 15 control rod scram time tests as described in Procedure No. TR-01, " Control Fod Drive Performance Test Procedure." The inspector examinec the results of the test performed on August 28, 1977.
The results indicated that the scram time of every rod was less than 1.5 seconds for full insertion.
The inspector reviewed information relating to Cycle 16 control rod scrar time tests as shown in Procedure No. TR-01.
The test was performed on April 7, 1979.
The longest scrar time was 1.5 seconds for Rod E-3.
The inspector concluded that Cycle 15 and 16 control rod scrar tests satisfied Technical 3pecification require =ents.
No items of noncompliance or deviations were identified.
5.
Shutdowm Margin Determination Big Rock Point Technical Specifications require that the shutdown cargin with the most reuctive control rod stuck out of the core be greater tnan 0.31 of reactivity.
The inspector examined information rela'
..g to Cycle 15 shutdown margin determination cs described in Test Procedure BRP-RE-8,
"Shutdcwn Margin Check Procedure," dated August 2, 1977.
The inspector noted that the initial condition was that all control rods were fully inserted and two channels of fission chambers w art placel in the cere in addition to the two fixed excore channels.
The teasurements of the steady state neutron count rates were recorded for all four channels.
Then a control rod wa: cocpletely withdrawn, and another control rod in the vicinity was withdrawn a few notches which were equivalent to an insertion of reactivity greater than 0.6I, as detercined by GROK.
The count rates of the four channels would increase and level off to new steady state values to verify that subtriticality was still maintained.
The new steady state count rates of the four channels were recorded. Measurements continued until sub-criticality of at least 0.62 reactivity was verified for every configuration with one rod full out and an adjacent rod partially out.
The inspector noted that the count rate of the incore Channel 9 was 350 cps (counts per second) prior to withdrawing any control rod, and when Rod A-3 was partially withdrawn and Rod A-2 was
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fully withdrawn, the count rate of Channel 9 dropped down to 55 cps.
All the other three channels showed increaser of count rates.
The licensee stated that the initial count rate of Channel 9 was probably 35 cps and was recorded incorrectly.
The inspector examined information relating to Cycle 16 shutdown margin determinatien dated April 10, 1979.
The test procedure used in Cycle 16 was identical to that described previousiv Shutdown margin of at least 0.6; was verified by measurements.
The inspector concluded that the shutdown margin determination was adequate.
No items of noncompliance or deviations were identified.
6.
Core Thermal Power Determination Big Rock Point administrative requirements state that the heat balance calculation shall be performed at least once per week by each shift.
The inspector noted that the licensee was fol-lowing their administrative requirements.
The inspectors examined information relating to the January 28, 1979, calculation of the core thermal power.
The Big Rock Point Facility does not have an online computer syster to perforn its thermal power det e rmina t ion.
The licensee utilizes Procedure T7-06, " Heat Balance Calculation," to ensure that the steady state reac*er power shall not exceed the Technical Specifications limits of thermal power and the high neutron flux scram setting.
The inspectors verified all the input parameters for the calcu-lations and performed an independent determination of the core thermal power.
The results were within la of the value determined by the licensee.
It was noted that the calculated value when compared with the instrumentation value indicated that the calce-lated power exceeded the low calibration acceptance criteria.
The inspector followed up on the recalibration of the three picoammeters and determined that the indicated readings were more conservative than the calculated power.
So items of noncompliance or deviations were identified.
7.
Review of Plant Operations The inspectors examined General Operating Procedure GOP1, " Plant Startup from Cold Shutdown," which included Master Checkoff Sheet (0-TGS-1) and the system checkoff lists for the systems disturbed
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or tested during the refueling outage.
It was verified that these systems were returned to an operating status prior to plant startur.
Some difficulty was encountered in the area of document control in the retrieval of the Master Checkoff Sheet.
The licensee explained that the difficulty was due to a revision of the master list and due to an unanticipated reactor scran.
A review of the licensee's Technical Data book, Volume 15 veri-fled the centrol rod withdrawal sequence and rod withdrawal authorization were in effect prior to startup.
The withdrawal sequence was developed by the computer progran GROK The inspectors also reviewed the operator's log book and verified of the proper rod withdrawal sequence on April 17, 1979.
the use The plant startup, heatup and approach to criticality were con-ducted in accordance with the approved GOPl.
The inspectors'
review of plant records and the discussion with the eperations supervisor verified that the technical specification require-ments were met during the entire approach to criticality.
So itens of noncompliance or deviations were identified.
6.
Exit Interview The inspectors met with licensee representatives (denoted in Para-graph 1) at the conclusion of the inspection on April 20 1979.
The inspectors sumnarized the purpose and the scope of the inspection and the findings.
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