ML20248J172
| ML20248J172 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 04/07/1989 |
| From: | Morris K OMAHA PUBLIC POWER DISTRICT |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| LIC-89-288, NUDOCS 8904140343 | |
| Download: ML20248J172 (6) | |
Text
{{#Wiki_filter:- - -_-_ Omaha Public Power District 1623 Harney Omaha. Nebraska 68102 2247 402/536 4000 April 7, 1989 LIC-89-288 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Station P1-137 Washington, DC 20555
References:
1. Docket No. 50-285 2. Letter from NRC (L. J. Callan) to OPPD (K. J. Morris) dated February 27, 1989 Gentlemen:
SUBJECT:
Response to Notice of Violation NRC - Inspection Report 50-285/89-02 Omaha Public Power District (0 PPD) received Reference 2, Notice of Violation. The violation concerned a failure to perform sufficient evaluations of Low Power Physics Test results and use of an incorrect equation in comparing test results to review criteria. Please find attached OPPD's response to this violation in accordance with 10 CFR Part 2.201. An extension was granted by the Senior Resident Inspector to provide adequate corrective actions. If you have questions concerning this response, please contact us. Sincerely, / K ). Morris Division Manager Nuclear Operations KJM/jak Attachment I c: LeBoeuf, Lamb, Leiby & MacRae R. D. Martin, NRC Regional Administrator P. D. Milano, NRC Project Manager j P. H. Harrell, NRC Senior Resident Inspector J 8904140343 890407 PDR ADOCK 05000285 Q PDC 1 \\ 45$124 Employment with Equal Opportunity Male / female L______._____ J
1 1 + Attachment RESPONSE TO NOTICE OF VIOLATION During an NRC inspection conducted on January 30 through February 3, 1989, a violation of NRC requirements was identified. The violation involved a failure to perform sufficient evaluations of test results. In accordance with the j " General Statement of Policy and Procedure for NRC Enforcement Actions," 10 CFR Part 2, Appendix C (1988), the violation is listed below: Criterion XI of Appendix B to 10 CFR 50, required, in part, that all testing shall be pcvformed in accordance with written test procedures which incorporate the requirements and acceptance limits contained in the applicable design documents. Furthermore, test results shall be documented and evaluated to assure the test requirements have been saticfied. The licensee has implemented these requirements, in part, in Fort Calhoun Station Procedure SP-PRCPT-1, Revision 28, " Post Refueling Core Physics Testing and Power Ascension," dated January 28, 1989. Contrary to the above, the following findings were made by the NRC i inspectors: A. Failure to Perform Sufficient Test Results Evaluallo_q The licensee failed to perform a comprehensive evaluation of test results, in that, data used in manual and computer software worksheet calculations for low power physics testing data reduction were in error. The failure to perform a sufficient results evaluation resulted in an erroneous moderator temperature coefficient which inaccurately represented the true margin of safety to the Technical Specification limit specified in Technical Specification 2.10.1(3)b. This is a Severity Level IV violation. (Supplement I) (285/8902-01) OPPD's Response 1. Reason for the Violation. if Admitted OPPD admits the violation occurred as stated. The reason for the violation were inadequate procedures and personnel error. The procedure in use at the time of the violation did not specify the steps to be followed when calculating the most positive Moderator Temperature Coefficient (MTC) from the measured Isothermal Temperature Coefficient (ITC). This calculation was performed by a qualified, knowledgeable and i experienced engineer without specific written guidance. The engineers i assigned to perform the Cycle 12 Low Power Physics Tests were highly qualified with experience ranging from three to six cycles of Low Power Physics Startup Testing. Page 1 J l
c \\ p I During the performance of Cycle 12-Low Power Physics Testing, OPPD began analyzing the data immediately following completion of each portion of the test. Once the data was collected and analyzed, the calculations were l checked by another test engineer not involved in the analysis process. This check was limited to a numerical check of calculations and was not a procedural requirement. Following completion of the last Low Power Physics Test, the data was analyzed, checked, and was compared against the acceptance criteria located in Appendix D of SP-PRCPT-1, "Special Procedure: Post Refueling Core Physics Parameter Evaluation." After i acknowledgment of meeting the acceptance criteria, the Plant Review Committee (PRC) members completed the necessary sign-offs for the beginning of power ascension. The NRC reviewed the ITC test data and discovered that an incorrect Fuel Temperature Coefficient (FTC) was applied to the MTC calculation which I resulted in a less conservative MTC than reported to the PRC. 5An FTC of -1.47 x 10-5 Ap/*F was used to calculate an MTC of +4.43 x 10- 3pf.p, The inspectors determined that this FTC value was not the FTC for Beginning ofgycle(B0C),HotZeroPower(HZP),andthatthecorrectFTCwas-1.97y 10 5 Ap/*F. Use of the correct FTC would result in an MTC of +4.93 x Specifications limit of +5.0 x 10-{ MTC did not violate the Technical 10-3pf.F. The corrected value o Ap/
- F.
OPPD has determined that the FTC used in the original calculations was the FTC at BOC, Hot Full Power (HFP). The Hot Full Power FTC value was located directly below the HZP value in the Cycle 12 Reload License Evaluation and was transposed incorrectly for use in the MTC calculation. The calculations were checked shortly after the completion of the ITC test, but the check did not ensure that the FTC used in the calculation was indeed the correct value. 2. Corrective Steps Which Have Been Taken and Results Achieved After the NRC inspector had identified the calculation error, an independent review of preliminary results was conducted. Concurrent with the independent review of the preliminary results, an investigation of the method used to derive the FTC was conducted due to concernoverthevalueofpredictgdMTCanditsmargintotheTechnical Specification limit of +5.0 x 10~ op/
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Combustion Engineering (CE) was consulttd and their review indicated that OPPD calculations used a significantly conservative application of physics methodology. CE offered an alternative to the OPPD calculation methods which more accurately predictsthgFTC. Application of this method resulted in an HZP FTC of -1.49 x 10~ ap/
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Upon completion of the FTC investigation in which Combustion Engineering participated and the independent review by 0 PPD, a memo was transmitted to the PRC containing the revised preliminary results from low power physics testing. The memo documented the measured and predicted MTC values and demonstrated acceptability of the results within the SP-PRCPT-1 acceptance and review criteria. The PRC reviewed and approved the revised information. Page 2
Formal analysis and analysis verification of the data collected during low power physics testing is conducted under the Production Engineering Division Quality Procedure PED QP-5. The Cycle 12 Engineering Analysis (EA) was completed, including analysis verification, on March 9,1989 and the results were within the acceptance criteria limits of Appendix D, Table 1, SP-PRCPT-1. Therefore, the error did not create a significant safety Concern. 3. Corrective Steos Which Will Be Taken to Avoid Further Violations Changes to SP-PRCPT-1 have been initiated which will require independent review of the preliminary results be performed and documented prior to presentation to the PRC. Data reduction and summary sheets which demonstrate acceptable or unacceptable test results will be included in the revision to SP-PRCPT-1. The summary sheet will also document the incorporation of the alternate FTC calculational method recommended by Combustion Engineering. These changes are to be implemented by June 30, i 1989. The rev'. sed procedure will be available for use prior to the next refueling outage. OPPD has reviewed other similar procedures and has determined that the procedures are adequate. 4. The Date When Full Comoliance Will be Achieved Full compliance will be achieved when SP-PRCPT-1 is revised by June 30, 1989. i Page 3
"B. Use of Incorrect Formula in Comparina results to Raview Criteria The licensee used a formula for evaluating ontrol element assembly group worths review criteria, which was different from that inferred q by the review criteria stated in Appendix D of the above referenced procedure. I This is a Severity Level IV violation (Supplement I) (285/8902-01) OPPD's Response l 1. Reason for'the Violation if Admitted l l The reason for the violation was inadequate procedures. The procedures in use at the time of the violation did not specify how data would be transmitted to the PRC.for their review. The procedure required. the Startup Test Group to reduce physics test data and compare the data to the acceptance criteria listed in Table 1 of Appendix D of the procedure. Once the comparison was completed and all low power physics test results I had met the acceptance criteria, the procedures allowed power ascension to commence. The PRC was required to review the results of the low power physics tests and give authorization to proceed with power ascension. l A summary sheet, entitled "Results from Cycle 12 Low Power Physics Testing" was created to give the test engineers a summary of the comparison of the test results to the acceptance and review' criteria and was intended to be used only within the startup test engineer group. Test results were added to this sheet after every test was completed and the results checked. Both measured and predicted values for each test were included along with review criteria' specifics with the exception of the control rod worths tests. Percent differences from the measured values of the control rod worths test were calculated in accordance with CE Topical Report for using the Rod Exchange Technique (CE NPSD-366) with the understanding that those percent differences were not part of tho SP-PRCRT-1 procedural requirements. The summary sheet was to be used within the startup testing group as a quick calculational guide only to see if any control rod group worths were close to or exceeded the acceptance criteria. A member of the PRC requested the summary sheet, made copies, and distributed the information 4 to the PRC without knowledge of the Startup Test Group. l 2. Corrective Steps Which Have Been Taken and Results Achieved PRC members were told st the preparation for power ascension meeting that the measured values were to be compared to those predicted in accordance with the acceptance and review criteria of Table 1 of Appendix D. Based j upon the results of the rod worth tests, no rod groups exceeded the ] l l criteria of +/-15% of the predicted worth. This was done as demonstrated l on a marked up copy of the summary sheet and retained by one of the PRC ] L members. After completion and acceptance of the values, the PRC completed i L the sign-offs for commencement of power ascension activities. These steps Page 4 e
~ comply with the requirements of SP-PRCPT-1. Therefore, OPPD believes that compliance with the procedure was achieved, however OPPD agrees with the NRC that documentation did not clearly support compliance to the procedure l in comparing measured to predicted values. l-A memorandum containing the revised preliminary results'from low power physics testing was transmitted to the PRC upon completion of an independent review. - This memo clearly documented the measured and predicted values and demonstrated acceptability with the SP-PRCPT-1 acceptance and review' criteria. The PRC reviewed and approved the revised information. 3. Corrective Steos Which Will Be Taken to Avoid Further Violations Changes to SP-PRCPT-1 have been initiated which require an independent review of the preliminary calculations to be presented to the PRC prior to power ascension. In addition, data reduction and summary sheets will be included as revisions to the procedure, which clearly require a comparison between predicted and measured values and either demonstrate acceptable or unacceptable test results. These changes are expected to be implemented by June 30, 1989. The procedures will not be used until the next refueling outage. l 4. The Date When Full Comoliance Will be Achieved Full compliance will be achieved when changes to SP-PRCPT-1 are implemented j by June 30, 1989. I I Page 5 l - _ _ _ _ - - - -}}