ML20214A257
| ML20214A257 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 05/13/1987 |
| From: | Brey H PUBLIC SERVICE CO. OF COLORADO |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| References | |
| P-87181, NUDOCS 8705190353 | |
| Download: ML20214A257 (6) | |
Text
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t 2420 W. 26th Avenue, Suite 1000, Denver, Colorado 80211 May 13, 1987 Fort St. Vrain Unit No. 1 P-87181 U. S. Nuclear Regulatory Commission ATTN:
Document Control Desk Washington, D. C. 20555 Docket No.
50-267
SUBJECT:
_ Inspection Report 87-08
REFERENCE:
NRC Letter, Gagliardo to Williams dated April 13,1987(G-87126)
Gentlemen:
This letter provides Public Service Company of Colorado's (PSC) response to the violations stated in the above reference.
The violations are the result of the inspections conducted at the Fort St. Vrain facility during the period of March I through March 31, 1987.
A.
Improper Calibration Criterion XI of Appendix B to 10 CFR Part 50 requires testing be
" performed in accordance with written test procedures which incorporate the requirements and acceptance limits contained in the applicable design documents." Appendix B to the licensee's r _..
FSAR, Section B.5.11.2, implements this by requiring procedures to incorporate or reference, "the requirements and acceptance limits contained in the applicable design or procurement
.g documents."
,q -
P-87181 JPaga 2 May 13,~1987
' Contrary.to the above:
1.
Pressure instrument number XI93508, a low range (0-100 psia) reactor coolant pressure instrument was calibrated using incorrect (psig vice psia) input values instrument numbers.
- and pressure 2.-
PI1108,-1109,-1110,(0-1000 psia) reactor coolant pressure instruments, were not calibrated over the full range of required use.
This is a Severity Level IV violation.
(Supplement I) (267/8708-01).
(1) The violation is admitted.
Reactor pressure indicator 'the pressure transmitter (PT-11270) is a 0-100 psia midrange digital instrument.
The instrument is located on Control Room Board I-09 and is used to verify compliance with Technical Specification LC0 4.2.7, PCRV Pressurization.
The pressure transmitter that provides a signal to XI-93508 was improperly calibrated. This was due to the incorrectly stated input units on the instrumentation calibration sheet (ICS). The inputs units were listed as " psi" rather than
" psia".
Reactor pressure indicators PI-1108, -1109, and -1110 are instruments with a 0-1000 psia range located on Control Room Board I-01.
These indicators receive a signal from a pressure transmitter which also provides a signal into the Plant Protective System (PPS) for a low reactor pressure scram.
These pressure indicators were being calibrated over a range of 400-800 psia.
This calibration range provided the highest degree of accuracy over the normal operating range.
However, since these indicators are also used to verify compliance with LC0 4.2.7 (100 psia) it is determined that this range of calibration is inadequate.
(2) The corrective steps which have been taken and the results achieved.
The improper calibration, which occurred on March 7, 1987, was resolved on March 14, 1987. A Station Service Request (SSR) No. 87503263 was initiated for work authorization to perform proper calibration of XI-93508 with the correct psia inputs and acceptance criteria. The ICS was also corrected with the proper calibration inputs.
Pressure indicators, PI-1108,
-1109, and -1110 were recalibrated under surveillance SR 5.4.1.1.9c-R over the range of 100-900 psia on April 3, 1987. A permanent change
P-87181-i Page 3-l May 13,'1987 was made to this procedure which incorporated the 100-900 psia range requirement.
(3) The corrective steps which will be taken to avoid further violations.
The modification made to the ICS for the low range pressure transmitter.is considered to be sufficient to avoid further violation in this area.
The permanent change to SR 5.4.1.1.9c-R that expanded the calibration range is sufficient to avoid any further violations.
(4) The date when full compliance will be achieved.
Compliance was achieved on March 14, 1987 with the correct calibration of the low range pressure transmitter.
As.the other pressure indicators were previously calibrated and the range of calibration recently expanded, these indicators are operating per design requirements.
The surveillance was completed on April 3,1987.
B.
Inadequate Review of Plant Equipment Change 10 CFR 50.59, " Changes, Tests and Experiments," allows the holder of a' license authorizing operation of a production facility to make changes in procedures or the facility itself without prior Commission approval unless the change involves a change in the Technical Specifications or an unreviewed safety question.
Contrary to the above, the licen<,ee designed, approved, reviewed, and installed a change to the reactor pressure vessel thermocouples which could not meet existing Technical Specification 5.4.1 testing requirements.
This is a Severity Level IV violation.
(Supplement I) (267/8708-03)
(1) The violation is admi'tted.
Design Change Notides (CNs) -2246 and -2144A authorized the replacement of non' environmentally qualified thermocouples with ones qualified to the FSV EQ Program bases. As part of this replacement, the electrical configuration was changed from a ' grounded' to an ' ungrounded' mode.
This electrical configuration change was prompted by noise problems _ induced by the presence of a ground loop between the thermocouple and the temperature transmitter output.
In addition to the noise problem, a buffer circuit was present to eliminate a transmitter loading problem and low output signals caused by impedance mismatches.
1
P-87181 Pags 4 May 13, 1987 The installation of the ungreeded thermocouples eliminated the need for the buffer cired6'wd allowed the use of an appropriate impedance inMt to the temperature transmitter as well as eliminating the ' ground loop.
LC0 4.4.1 and SR 5.4J r.rovide the limiting conditions for operation and surveillance requirements for the Plant Protective System (PPS).
Surveillances are performed to verify and demonstrate operability of instrumentation and control functions.
As delineated in SR 5.4.1, the method of verification may vary with each parameter.
For the circulator inlet temperatures and the Loop 1/ Loop 2 superheat header temperatures, an internal test signal is pied to verify trips, alarms, and setpoints.
The internal test signal for the above temperature channels is generated from a Modular Test Unit (MTU) within the PPS bins.
The test signal is used to verify the ope: 4. ting requirements.
As cited in the violation, the above CNs involved a design oversight in that the MTU test signal was not modified to be compatible with the utilization of the new ungrounded thermocouples. The Independent Design Verification (IDV) missed the design oversight and it was not discovered in the 10CFR50.59 review process. Ultimately, the design control system did work as the design oversight was identified by PSC in the functional test (FT) process specified in the CNs. The discovery was made before the temperature channels were placed into service even though the earlier lines of review missed the design oversight.
The system as designed would have worked properly since the temperature transmitter configuration was changed to be compatible with the ungrounded input signal from the newly installed thermocouples. The MTV, which is only switched into the channel circuitry during testing, remained the only device incompatible with the channel configuration. The PPS functions were not degraded by the deficiency.
The Technical Specifications, as written, provide overly restrictive means for demonstrating operability requirements.
The method specified did not permit the diversity and flexibility of using either an internal or external test signal appropriately applied.
(2) The corrective steps which have been taken and the results achieved.
To achieve confermance with the existing Technical Specification surveillance requirements, isolation transmitters have been installed in the respective PPS bins to isolate the grounded internal test signal from the MTU.
This modification allows use of the existing internally j
P-87181 Page 5 May 13, 1987 generated test signal to demonstrate operability requirements.
In addition, a formal Technical Specification amendment request has been submitted (PSC letter, Williams to Calvo, dated April 23,1987) to remove the requirement to use the
" internal" test signal for this particular parameter as well as other PPS parameters. This amendment request will allow for diversitv and flexibility by using either an internal or external signal appropriately applied. The internal test signal will remain the preferred method while use of equivalent external test signals are equally acceptable.
Further action is also underway as part of the FSV Technical Specifications Upgrade Program (TSUP) to significantly improve the overall Technical Specifications and bases.
This task is directed to achieve a set of Technical Specifications more in line with the Standard Technical Specifications (STS).
(3) The corrective steps which will be taken to avoid further violations:
In the 1986 'SALP response on design control, a commitment was made to establish an issue specific design control task force to investigate the design control process.
As a result, the design control task force set forth to investigate all items uhich directly and indirectly affect the design change system. This includes, but is not limitea to, such items as processes, procedures, design documents, data bases, design inputs and interfaces. The task force also has reviewed INP0 Good Practices TS 402 Plant Modification Control Progrr.m. The task force is continuing its investigation on the design change and modification process and is formulating recommendations.
The design oversight as cited in (1) above will be reviewed by the design control task force for overall process and procedure implications.
In the interim as an overall immediate corrective action, a memo will be prepared which discusses the design oversights cited in the violation and routed to individuals within the Nuclear Engineering Division and Nuclear Licensing Division who either prepare the Change Notices, perform the design reviews of the Change Notices, prepare Change Notice safety evaluations, or review these safety evaluations.
This memo will provide background information on the design changes and highlight the design oversights and the necessity for in-depth design and 10CFR50.59 safety evaluations. The memo will also require individual sign-off that the individual has read and reviewed the contents of the memo.
J
P-87181 Pag? 6 May 13, 1987 In the long term, the reconsnendations of the design control task group will be evaluated and implemented as appropriate.
Revisions to the design control system will necessarily require procedural revisions and in-depth training for assuring the proposed modified configuration is compatible with all interfacing systems and equipment.
(4) The date when full compliance will be achieved.
The installation and functional testing of the isolation transmitters to allow the utilization of the internally generated test signal to comply with the Technical Specification surveillance requirements was completed March 30, 1987.
This resolved the specific design oversight covered by this violation.
The preparation of the memo highlighting the design oversights noted in this violation and the routing for individual sign-offs will be completed by June 1, 1987.
The finalization of the design control task group's recommendations and plans are scheduled to be completed in August, 1987. Approval and implementation schedules will be developed fol, lowing finalization of the restructuring plan.
Should you have any questions concerning this response, please contact Mr. M. H. Holmes at (303) 480-6960.
Very truly yo,urs, Ms H. L. Brey, Manager Nuclear Licensing and Fuels Division HLB /JS:jmt cc: Regional Administrator, Region IV Attention: Mr. J. E. Gagliardo, Chief Reactor Projects Branch Mr. R. E. Farrell Senior Resident Inspector Fort St. Vrain
.