ML20234B108
| ML20234B108 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 12/30/1987 |
| From: | Cockfield D PORTLAND GENERAL ELECTRIC CO. |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| NUDOCS 8801050443 | |
| Download: ML20234B108 (9) | |
Text
-
m_
m Portland General Electric Coiripesiy David W. Cockfield Vice President, Nuclear December 30, 1987 Trojan Nuclear Plant Docket 50-344 License NPF-1 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington DC 20555
Dear Sir:
Response to Notice of Violation Your letter of November 30, 1987 transmitted a Notice of Violation associated with NRC. Inspection Report 50-344/87-40. Our reply to the Notice of Violation is provided in Attachment A.
In addition, your transmittal letter requested responses to the related issues raised in Inspection Report 50-344/87-37; these responses are provided in Attachment B.
Attachment C containe background information relating to the Notice of Violation.
Sincerely, Attachments c:
Mr. John B. Martin Regional Administrator, Region V U.S. Nuclear Regulatory Commission Mr. William Dixon State of Oregon Department of Energy Mr. R. C. Barr NRC Resident Inspector Trojan Nuclear Plant
~8801050443 871230 PDR ADOCK 05000344 DCD i
l 0
121 SW. Raimon Strwt Portland. Oregon 97204 L--_-__-
Trojan Nuclear Plent Document Control Desk Docket 50-344 December 30, 1987 License NPF-1 Attachment A Page 1 of 3 REPLY TO NOTICE OF VIOLATION Violation A 10 CFR 50, Appendix B, Criterion V, states in pnet, " Activities affecting quality shall be prescribed by documented instructions, procedures, or draw-ings, of a type appropriate to the circumstances and shall be accomplished in accordance with these instructions, procedures or drawings."
Plant Periodic Operating Test POT-28-1, Core Quadrant Power Tilt Ratio Verification, Revision 8, specifies in part that QPTR values exceeding 1.020 after calculations using nuclear instrumentation detector voltages shall be confirmed by performing a nuclear instrumentation detector current calculation.
Contrary to the above, during three instances of required technical specifica-i tions surveillance testing performed on September 12 September 19, and l
September 26, 1987, detector current calculations were not performed after detector voltage calculations showed QPTR values exceeding 1.02.
PGE Response 1.
Reason for Violation i
PGE admits the violation. The Core Quadrant Power Tilt Ratio (QPTR) cur-rent calculations were not performed as referenced in POT-28-1.
The reason for the violation was procedural noncompliance.
The responsible Engineering and Operations Department personnel aid not consider it necessary to strictly comply with the procedure because of the following circumstances:
a.
The core power distribution was normal and no alarm condition existed from flux map and QPTR trending.
b.
The QPTR alarm circuits were not precise since they had not yet been tuned-up with high power level data.
c.
The QPTR procedure assumes that the QPTR instrumentation is fully tuned-up and calibrated.
2.
Corrective Steps That Have Been Taken and the Results Achieved Corrective steps have been taken to counsel the persons involved regarding the need for literal procedure compliance. Also, the Core QPTR Verifica-tion procedure, POT-28-1, has been revised to reflect the QPTR issue back-ground and to improve the guidance provided concerning when supplemental nuclear instrumentation detector current calculations are required.
A license change request has been initiated to clarify the Technical Specification basis section for QPTR surveillance.
Trojan Nuclesr Plcnt Document Control Desk Docket 50-344 December 30, 1987 License NPF-1 Attachment A Page 2 of 3 3.
Corrective Steps That Will Be Taken to Avoid Further Violations Procedure compliance will continue to be emphasized with Plant personnel by Trojan and PGE management. Critique sessions devoted to specific inci-dents of procedure noncompliance will be conducted.
4.
The Date When Full Compliance Will Be Achieved With the procedure compliance critique session that was held on December 17, 1987 and the revision to POT-28-1 that was completed in late December 1987, full compliance has been achieved Although it is expected that the Technical Specification QPTR basis will be changed by August 31, 1988, this action is not considered necessary to achieve full complianco.
Violation B Technical Specification 4.10.1.2 states, "Each full length rod not fully inserted shall be demonstrated operable by verifying its red drop time to be less than or equal to 2.2 seconds within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to reducing the shut-down margin to less than the limits of Specification 3.1.1.1."
Contrary to the above, during low power physics testing conducted in July 1985, September 1984, and July 1983, rod drop time measurement was performed for only one full length control rod (at location K-06) within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to reducing the shutdown margin to less than the limits of Specification 3.1.1.1.
PCE Response 1.
Reason for Violation PGE admits the violation. The reason for the violation was personnel error in that the PGE-approved method for meeting the rod drop survell-lance requirement did not satisfy the literal wording of the Technical Specification regarding shutdown margin.
2.
Corrective Steps That Have Been Taken and the Results Achieved l
Corrective steps have been taken to counsel the persons involved regarding literal procedure compliance.
A license change application has been initiated to change the allowable time between rod drop time measurements and reducing the shutdown margin. Consistent with industry practice and the NRC approved Westinghouse Standard Technical Specifications, the allowable time lapse will be increased from 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to seven days.
Trojen Nuclear Plent Docum:nt Control Desk Docket 50-344 December 30, 1987 License NPF-1 Attachment A Page 3 of 3 l
i 3.
Corrective Steps That Will Be Taken to Avoid Further Violations Procedure compliance will continue to be emphasized with Plant personnel by Trojan and PGE management. Critique sessions devoted to specific inci--
dents of noncompliance will be conducted.
In addition, the startup low power physics test procedure, Periodic Engineering Test (PET) 13-1, will be revised to reflect the Technical Specification surveillance require-ments. This will be accomplished prior to startup from the 1988 refueling outage (approximately May 20, 1988).
4 The Date When Full Compliance Will Be Achieved A procedure compliance critique session was held on December 17, 1987.
The revision to PET 13-1 will be completed prior to Cycle 11 startup physics testing (approximately May 20, 1988), at which time full compliance will be achieved.
I 2191W.1287 L____________.__
Trojen Nuclear Plant Documint Control Dask Docket 50-344 December 30, 1987 License NPF-1 Attachment B Page 1 of 3 INSPECTION REPORT 50-344/87-37 OPEN ITEMS A.
Open item 87-37-01, POT-28-1, Core Quadrant Power Tilt Ratio (QPTR)
Verification The following issues were raised in this open item:
1.
There were no positive controls in place to assure that the QPTR was determined to be within limits prior to exceeding 50% power as required by Technical Specification 4.2.4.
PGE Response Technical Specification 4.2.4 requires determining the QPTR above 50 percent of rated power and is-applicable above 50 percent of rated power. QPTR monitoring was performed at 50 percent power in accordance with the Reload-At Power Test procedure, PET 13-2, to satisfy the Technical Specification 3.2.4 requirement before the use of the QPTR verification procedure, POT-28-1, was required.
The notification that testing is required at 50 percent power is made via the Plu.ning/ Scheduling Group and the testing plateaus identified in PET 13-2.
No-load and at-power data has always been reliably collacted following Trojan core reloads.
2.
The Plant Operating Test did not specify a time frame for performing backup calculations to determine that the QPTR was within limits.
PGE Response POT-28-1 specified an allowed time for taking action that was more conservative than the Technical Specification 3.2.4 requirements fol-lowing confirmation of an excessive QPTR. The action required by the Technical Specifications is based upon having a valid core power tilting problem.
The definition in the Technical Specifications (Section 1.18) for QPTR specifies that excore detector calibrated outputs be used. Since the procedure assumed that fully calibrated outputs were used, abnormal time delays occurred when discussions with the cognizant engineers by Operations personnel, concerning the fact that a flux map had shown that a true core power tilt did not exist, led to the understanding that the detector current calculations were not required. Procedures 4
that implement Technical Specification requirements must allow a reasonable time interval to conduct confirmatory testing. PGE does not agree that a specific time frame should be specified in this procedure, provided timely efforts are made to resolve the problem.
I
c Trojan Nuclear Plant Document Control Desk Docket? 50-344' December 30, 1987 License NPF-1 Attachment B Page 2 of 3 3.
The actions required by POT-28-1 if the QPTR was detennined to exceed limits were incomplete and inconsistent with the Technical Specifications.
PGE Response
,The actions specified by POT-28-1 were more conservative than the requirements stated in the Technical Specification. The procedure will be revised to be consistent with the Technical Specification requirements.
B.
Open item 87-37-02, Rod Drop Time Testing During Physics Testing The following issues were raised in this open item:
1.
The manual reactor trip and measurement of the drop time of the most reactive control rod may not have fully met the requirements of l
Technical Specification 4.10.1.2 which calls for the measurement of l
rod drop time within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of reducing the shutdown margin below l
normal limits.
PGE Response PET 13-1, Reload Low Power Physics Tests, does not meet the literal requirements of Technical Specification 4.10.1.2, but does appear to agree with industry practice among Westinghouse plants which use the special test exception. PET 13-1 will be revised to reflect the specific Technical Specification requirements.
2.
Rod drop times have not always been measured from the fully withdrawn position.
Also, digital rod position indication status lights and a stopwatch were used rather than Periodic Instrumentation and Control Test, PICT-16-1, methods.
PGE Response At the time of the physics test manual trip and most-reactive rod timing in PET 13-1, the controlling bank C was not at 226 steps. To maintain criticality, small changes in rod position had been required.
In this case the controlling bank contained the most reactive rod and had been inserted to 197 steps. The bank position was noted in the testing procedure to allow for proper interpretation of drop time. With the rods somewhat inserted, the effective rod drop time was one or two tenths of a second slower; however, the rod drop time, using three watches and measured by three persons, was well l
within limits (1.7 seconds) using the slowest measured time.
In the future, rod drop times will be measured from the fully withdrawn position and the methods of PICT-16-1 will be used.
(
i
.'3-
' O Trojan Nuclear' Plant Document Control Desk Docket 50-344-December 30, 1987 License NPF-1 Attachment B Page 3 of 3 The significance of explicitly measuring the most reactive rod (K6) l was to cover the eventuality of performing an All-Rods-In-Minus-One,
-rod worth measurement program,'which had always been done'in the past at Trojan. For shutdown margin determination in physics testing, the most reactive' rod i's the most important rod.
3.
The rod insertion limit for control bank C at'zero power is 118: steps.
versus 100 steps shown in the procedure.
PGE Response Procedure PET-13-1 did incorrectly reference 100 steps versus 118 steps for the control bank C cod insertion limit.at zero power..This
-will be corrected in the forthcoming procedure revision.
Procedure PET-13-1 will be revised to require the performance of PICT-16-1 within the time interval stated in our Technical Specifications by May 1988.-
License Change Application 153 has been submitted to the NRC to presumably make the Plant trip during physics testing unnecessary.
I l
l s
T l
l' t
2191W.1287 i
1
l Trojan Nuclear plant Document Control Desk l
Docket 50-344 December 30, 1987 l
License NPF-1 Attachment C Page 1 of 2 BACKCROUND INFORMATION Violation A A contributing aspect to the noncompliance was the detailed knowledge of the Sackground of quadrant power tilt ratio (QPTR) surveillance possessed by the cognizant supervisor that was not stated in the procedure itself..
QPTR monitoring described in Periodic Operating Test (POT) 1 describes different ways to calculate QPTR using various instrumentation and calls for confirming power tilt indication before considering an abnormal tilt indication as valid.
The use of the movable flux detector system is the most precise method of determining QPTR and can stand alone. All other methods of calculating QPTR are based upon the flux detector system for calibration.
The other methods [ Nuclear Instrumentation System (NIS) recorder voltage hand calculation, NIS voltage P-260 calculation, and NIS raw current hand calculation) are not as precise and need to be " tuned-up" at full power to improve the quality of their calibration which was installed at 50 percent power. The other methods are always valid for monitoring core power relative change, as opposed to absolute value, even when not fully calibrated.
POT-28-1 was written assuming that all systems are fully calibrated in determining the progression of steps through the procedure. When a flux map has been recently taken that shows balanced quadrant power, and alternate Plant indications (ie, digital rod position indication and reactor coolant loop delta temperatures) are normal, and QPTR instru-mentacion shows only small relativo changes form the flux map reference case, then there is no core QPTR safety concern. Additional calculations using NIS current data are not useful if the reference NIS current values themselves are not determined at high power flux map conditions.
The Shif t Supervisor properly informed the cognizant engineer or his assistant of the tilt alarms from the NIS instrumentation and was told the background information. A memorandum (FJU-005-87) was sent to Cperations Department on October 6, 1987, giving additional guidance regarding when supplemental calculations were required. However, the memorandum content should have been embodied within the procedure itself.
1 In January 1985, a memorandum (WSO-030-85) was sent to the Nuclear Safety
& Regulation Department discussing the issue of QPTR instrumentation capabilities and technical specification requirements and asking for a clarification or change from the Nuclear Regulatory Commission (NRC) regarding the basis section of the QPTR technical specification.
The request for assistance with the technical specification basis citrifica-tion is still open.
L rojan' Nuclear Plant Document Control Desk T
Docket 50-344 December 30, 1987 License NPF-1.
Attachment C a
Page 2 of 2 Violation B A feature of this testing program is to conduct rod worth measurements by diluting into the core several rod banks while maintaining criticality.
The rod banks may be diluted in'until all rods except one rod, the most reactive one, are inserted. This technique had been done for all Trojan cycles to date. Before diluting the rods into a point where normal shut-down margins are not mot, the technical' specifications ask for insurance
-of the'tripability of the withdrawn rods with a drop time less than 2.2 seconds within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of reduced shutdown margin testing.
The Trojan philosophy in meeting the surveillance requirement, which agraes with' industry practice, has been to perform' the individual rod de>p time measurements per Periodic Instrumentation and Control Test (PICT: 1, Hot Rod Drop Time Measurements, prior to cycle criticality and phycles testing. This testing normally occurred two or three days
'before criticality.
Each rod drop time to dash pot entry was verified
<2.2 seconds. When physics testing began and the reactor went critical, Control Bank D was subsequently diluted in fully and reactor criticality was maintained with Control Bank C normally near the full out position.
At this condition, the reactor was manually tripped &nd the test engi-neers watched the digital rod position indication system to verify that all withdrawn rods uniformly fell,into the core. They measured the drop
(
time of one rod, the most reactive control rod, with stopwatches. The drop time of this rod was verified to be less than 2.2 seconds.
The drop times of the other rods are.not quantified individually, though the uniformity of digital rod position indication light diode changes showed relative positicns of the rods during the fall to be within six steps of each other and very close in time qualitatively to the measured rod drop time.
It is believed by the responsible engineer that the method of rod drop verification meets the intent of the surveillance requirement, although not meeting the literal surve!Ilance wording. A License Change Request (WSO-062-86) was submitted on February 21, 1986, to amend'the license-surveillance requirement wording to formally take credit for PICT-16-1 rod drop testing occurring seven days prior to physics testing to make physic testing more efficient by avoiding the necessity for a manual reactor trip and the personal safety hazard involved with pulling rod power fuses should PICT-16-1 he performed. The License Change Application was cent to the NRC in October 1987.
It should be noted that the-Trojan opproach to satisfying the surveil-lance requirement agrees with industry practice among Westinghouse plants in the different NRC regions. This was verified again in discussion with Westinghouse startup test engineer (Michael Heibel - Nuclear Operations) who suggested that NRC-Region V contact NRC-Bethesda (Margaret Chatterton).
SAB/kal 2158P.1287
_j