IR 05000335/1978024
| ML17206A574 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 11/09/1978 |
| From: | Burnett P, Martin R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML17206A572 | List: |
| References | |
| 50-335-78-24, NUDOCS 7812210154 | |
| Download: ML17206A574 (8) | |
Text
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+p*y4 Report No.
50-335/78-24 Docket No.
50-335 License No.
DPR-67 UNITED STATES NUCLEAR REGULATORY COMMISSION
REGION II
101 MARIETTASTREET, N.W.
ATLANTA,GEORGIA 30303 Licensee:
Florida Power and Light Company P.O.
Box 529100 Miami, Florida 33152 Facility Name:
St. Lucie
Inspection at:
St. Lucie Site, Hutchinson Island, Florida Inspection conducted:
October 9-11, 1978 Inspector:
P. T. Burne Approved by R. D.
M rtin, Chief Nuclear Support Section No.
Reactor Operations and Nuclear Support Branch
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Da e
Ins ection Summar Ins ection on October 9-11 1978 (Re ort No. 50-335/78-24)
who spent 15 hours1.736111e-4 days <br />0.00417 hours <br />2.480159e-5 weeks <br />5.7075e-6 months <br /> on-site reviewing systems and programs for core performance monitoring, surveillance of core performance and licen'se event reports.
Results:
No items of noncompliance were identified in the 3 areas inspected.
T S12210 X SP
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RII Rpt.
No. 50-335/78-24 DETAII,S I Prepared by:
. Burn, eactor Inspector Nuclear Support Section No.
Reactor Operations and Nuclear Support Branch Date Dates of Inspection:
October 9-11, 1978 Reviewed by:
R.
D. Martin, Chief Nuclear Support Section No.
Reactor Operations and Nuclear Support Branch
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1.
Persons Contacted
"C.
MJ
"R
"G.
- R
"A.
Va M. Wethy, Plant Manager H. Barrow, Operations Superintendent E. Bowers, Maintenance Superintendent K. Ryall, Reactor Supervisor M. Vaux, QC Supervisor R. Jennings, Technical Supervisor Roos, QC Staff M. Anderson, Plant QA rious plant control room personnel 2.
- Indicates attendees at exit interview on October ll, 1978.
Licensee Action on Previous Ins ection Findin s 3.
Not addressed.
New Unresolved Items Unresolved items a'e about which more information is required in order to ascertain whether they are acceptable items, items of noncompliance or deviations.
An unresolved item disclosed during this inspection is discussed in Paragraph 5.
4, Mana ement Meetin The inspector met with Mr. C. M. Wethy, Plant Manager, and those persons indicated by asterisk in Paragraph 1 on October ll, 1978.
The scope and findings of this inspection were reviewed for those present.
In the course of this meeting plant management made a
commitment to modify Operating Procedure 3200050,
"Calculation of Incore Alarm Setpoints" as further described in Paragraph 6 of these detail RII Rpt.
No. 50-335/78-24
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S stems and Pro rams for Monitorin Core Performance The incore flux monitoring system consists of 45 strings of 4 self-powered neutron detectors each, which are installed in fixed locations in the core.
Electrical signals from these detectors are converted to flux units in the plant data digital data system by application of initial calibration factors and continuously updated burnup correction factors.
The output from this system is a punched paper tape.
That tape is then carried to an onsite data-link facility where it is read and transmitted over telephone lines into the NSSS vendor's facility in Connecticut.
The vendor by means of one of several available proprietary computer codes analyzes the flux data and determines the power distribution parameters, including those for which there are Technical Specification limits such as azimuthal power tilt and total radial peaking factors.
The vendor also calculates the alarm setpoints for the incore detectors for monitoring linear heat rate.
These results and other information are then transmitted to the licensee over the same phone lines and data-link system.
In observing and reviewing the use of the data link, the inspector confirmed from onsite records of correspondence that tests had been made of the system to confirm that data transmitted from the plant to the vendor produced the same calculational results as identical data input directly into vendor facility.
That this work was done and the results made available for comparison is documented.
The available documentation does not confirm that the comparison was made or that it was found acceptable.
The licensee is currently reviewing its corporate files to determine if other documentation or the necessary documentation exists.
In the interim, this subject of data-link suitability has been identified as Unresolved Item 335/78-24-01.
Orginally, the licensee's flux data were analyzed using NSSS vendor's code GINCA, in which one-eighth-core symmetry was assumed.
This allowed reflection of all incore detectors into one octant, it effectively made the extrapolation of flux observations or interpo-lations between them to be over fairly short distances.
Following the failure of some burnable poison rods, the licensee's core developed a nonsymmetric power distribution, and most of the analyses of cycle 1 were carried out using the vendor's CECOR code in which symmetry was not assumed but obviously the extrapolation and inter-polation distances between flux points were greater.
The licensee has only limited familiarity with the functioning of these codes, since they are proprietary to the NSSS vendor, and are not available to them for examination.
The licensee has not.been able to indepen-dently verify that the method by which these codes calculate azimuthal power tilt is in fact correct.
The licensee based or justified their use of the results from these codes on the basis of their
RII Rpt.
No. 50-335/78-24 understanding from the vendor that they had been thoroughly reviewed and approved for use by NRR.
The inspector stated the he would independently address these understandings.
The method of determining azimuthal power tilt prescribed by the.vendor does not assume that any detector or group of detectors uniquely defines a predetermined quarter of the core.
Instead, it is assumed that the axes defining the quadrants are free to rotate to encompass the highest-powered quarter-section of the core.
Hence, an azimuthal power tilt calculated by CECOR from data derived from the incore detectors has both magnitude and angle with respect to core north'oth magnitude and angle are sensitive to a dropped rod.
During the current cycle, the tilt angle has changed about 60 degrees from +129.6 degrees (June 9) to -169.28 degrees (October 6).
Except for instances of dropped rods, the amplitude of the tilt has been much less than the limits in Technical Specifi-cations.
Hence, the angle is quite sensitive to small changes in power distribution.
The licensee attributes the tilt at the beginning of the cycle and its slow variation in angle to.
the uneven core burnup experienced in cycle 1 as a result of the nonsymmetric failure of burnable poison rods'.
Surveillance of Core Performance The following operating procedures and periodic tests were reviewed for content or performance or both as indicated below.
OP 0110057,
"Periodic Surveillance of DNB Margin."
This procedure is performed to meet the requirements of Technical Specification 3.2.
The procedure was reviewed for content, and plant records were examined to confirm that the surveillance was performed each shift in the period of September 12 to October 9, 1978.
OP 1200022,
"Periodic Surveillance of Incore Detector System."
This procedure was reviewed for content only.
Co OP 3200020,
"Primary System Calorimetric".
This procedure was reviewed for content and for performance.
Examination of facility records confirmed daily performance for the period September 12 to October 9, 1978.
Some of the calculations were checked for arithmetic correctness, and no errors were found.
Observations in the control room also confirmed that up-to-date information necessary to these calculations was available in the plant curve boo C rt
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l RII Rpt. No. 50-335/78-24-4-d.
OP 3200052,
"Monitoring LHR With Excore Detector Monitoring System".
This procedure, written to meet the requirements of Technical Specifications 3.2.1 and 4.2.1, was reviewed for content only.
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OP 3200053,
"Surveillance Requirements for Azimuthal Power Tilt (Tq)". This procedure, which addresses requirements of Technical Specification 4.2.3.2, was reviewed both for content and performance.
Review of plant records confirmed that this surveillance was performed as required since the startup for cycle 2.
f.
OP 3200054,
"Surveillance Requirement For Total Radial Peaking Factor (FRT)".
Performance of this procedure is required once every 31 accumulated days of operations.
It was reviewed for both content and performance, and plant records confirmed that the procedure had been completed in July, August and September of 1978.
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OP 3200057,
"Calculation of PDg RMS Deviation".
This procedure was reviewed for content only.
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OP 3200058,
"Surveillance Requirement for Total Planar Radial Peaking Factor".
This procedure was reviewed for content only.
Following the review of the procedures described above and discussions with plant personnel, the inspector had no questions on their content or application.
7.
Licensee Event Re orts Licensee Event Report 335-78-31 described an occurrence in which erroneous data were transmitted to the licensee by the NSSS vendor following a CECOR run.
These data, which were the new monthly alarm setpoints for the incore detectors to monitor linear heat rate limits actually resulted in nonconservative alarm limits being inservice for some hours.
The inspector reviewed the event with licensee personnel, and discussed with them their informal corrective action taken to date.
Following discussions with the inspector, the licensee made a formal commitment to formalize and augment their corrective actions in this area as follows:
Operating Procedure 3200050,
"Calculation for Incore Alarm Setpoints" will be revised to provide a handcheck of incore alarm setpoint calculations.
The check will provide verification for each of the four levels of detectors and when completed it will be attached to the alarm setpoint documentation.
Concomittantly, the licensee
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RII Rpt.
No. 50-335/78-24 will do a qualitative check of the alarm setpoints of that calculation to confirm its reasonableness.
The procedure will further be revised to update the Technical Specification references therein.
This revision will be completed by October 25, 1978.
(0P "
78-24-02)
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