ML17326A983
| ML17326A983 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 09/03/1985 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML17326A982 | List: |
| References | |
| NUDOCS 8509170092 | |
| Download: ML17326A983 (7) | |
Text
UNlTEO STATES NUCLEAR REGULATORY COMMISSION WASHINGTON. 0 C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.
91 TO FACILITY OPERATING LICENSE NO.
DPR-58 INDIANA AND MICHIGAN ELECTRIC COMPANY DONALD C.
COOK NUCLEAR PLANT UNIT NO.
1 INTRODUCTION DOCKET NO. 50-315 Westinghouse Electric Corporation notified Indiana and Michigan Electric Company (licensee) on Nay 2, 1985 that they had found an error in their cali-bration allowance for Resistance Temperature Detectors (RTDs) manufactured by The NRC was notified of this error by a Westinghouse letter dated Nay 6, 1985.
This error resulted from calibrtions performed by RdF that showed a non-compatibility with the presently accepted Westinghouse instrument un-certainty assumed in the analysis.
Westinghouse has evaluated the impact of these calibration errors and has determined that certain changes to the Tech-nical Specifications should be made.
The proposed changes to the D. C. Cook Unit No.
1 Technical Specifications would accommodate the use of any of the 16 RdF RTDs.
Two of the RdF RTDs are already installed in Unit 1 as spares with the remaining 14 being installed dur-ing the current refueling outage as replacements for Rosemount manufactured RTDs.
These RTDs are used for temperature input to Overtemperature M, Over-power &T, l.oss of Flow, DNB protection and Tavg low-low Essential Safety Features (ESF Actuation).
EVALUATION AND CONCLUSION - CALIBRATION ALLOWANCE ANO CHANGES TO SETPOINIS By letters dated July 30 and August 13, 1985 from N. P. Alexich to Harold R.
Denton, the licensee proposed changes and provided justifications for these changes for the D. C.
Cook Unit No.
1 Technical Specifications.
These changes 8509i70092 850903 t
PDR ADOCK 05000318 P
2 that time, plant startup was scheduled for August 10, 1985 and reaching mode 3 on August 18, 1985.
In our review of the licensee's efforts to resolve this matter, we. have determined that the submittals were timely and made on a best effort basis.
The proposed amendment was noticed in the Federal Register on August 2, 1985 with comnents due by August 16, 1985; less thah the 30 days usually provided for convent but before the planned startup.
Subsequent to that time, the licensee l'as experienced difficulty in startup with significant delays due to failures I
during a hydro test, repeating the integrated leak tate test after correcting value lineups, and performing unplanned cre0fce flushing on the steam generators.
Startup is now scheduled after September 7, 1985.
Although there has been some unanticipated delay fn startup, the licensee responded promptly and reasonably to the unforeseen need for technical specification changes required to prevent anticipated delay fn startup of the facility.
The proposed changes to the D. C. Cook Unit No.
1 Technical Specifications would accommodate ke use of any of the 16 RdF RTDs.
Two of the RdF RTDs are k'lready installed in Unit 1 as spares with the remaining 14 being installed dur-ing the current refueling outage as replacements for Rosemount manufactured RTDs.
These RTDs are used for temperature input to Overtemperature Z9, Over-power L9, Loss of Flow, DNB protection and Tavg low-low Essential Safety Features (ESF Actuatfon).
EVALUATION AND CONCLUSION <<CALIBRATION ALLOWANCE AND CHANGES TO SETPOINTS By letters dated July 30 and August 13, 1985 from M. P. Alexich to Harold R.
Denton, the licensee proposed changes and provided justifications for these changes for the D. C.
Cook Unit No.
1 Technical Specifications.
These changes resu1ted from the replacement of the Rosemount RTDs with RdF RTDs.
Tli~ changes reviewed encompass the changes to Table 2.2-1, Functional Unit 7, 8 and l2; notes associated with Table 2.2-1; and Table 3.3-3, Functional Unit 4f.
The changes channels (i.e., Overtemperature L9, Overpower&7, Low Flow).
For the pro-tection functions it was determined that the Safety Analysis Limit/Nominal Trip Setpoint relationship was sufficient to accommodate the changed uncertainties without causing changes to the Safety Analysis Limits or Nominal Trip Setpoint.
Utilizing the information noted above, an evaluation was performed which indi-cated that the current DNBR design limits are not impacted by the revised values.
This evaluation demonstrated that installation of RdF RTDs (with increased and reallocated uncertainties over the currently installed RT9s) will not impact the Safety Analysis Limits assumed, nor the core limits utilized, in the plant's safety analyses.
The only significant changes to the plant are the Allowable Values for several protection functions and the indicated Tavg value in the Unit I Technical Specifications.
Nominal Trip Setpoints in the Technical Specifications remain unaffected.
Based on the above the staff concludes that the only impact on the plant, due to the installation of RdF RTDs, is the changing of the Allowable Values for the protection functions indicated and the staff has found these changes acceptable.
Therefore, the staff considers the Technical Specification re-visions noted above to be acceptable.
EVALUATION AND CONCLUSION - 7 AND TESTS ABOVE P-12 SETPOINT By letters dated July 30, 1985 and August I3, 1985, from M.
P. Alexich to H.
R. Denton, the Indiana and Michigan Electric Company proposed administrative controls for D.
C.
Cook Unit No.
1, to maintain the T
safety signal in the avg tripped condition when operating above the P-I2 setpoint.
This administrative
C
~
4 action is only required for Cycle-9 until the licensee confirms that by replacing the RTGS (Resistance Temperature Devices) manufactured by Rosemount to those manufactured by RdF would not result in measurement uncertainties which exceed those assumed in the FSAR transient and accident analyses.
This administrative control will assure that the consequences of a main steam line II break will lie within the limits analyzed in the FSAR.
Since both the safety injection actuation and steam line isolation signals are generated by a lo-lo average coolant temperature (T
) coincident with high steam flow, avg maintaining the,T
', signal in a tripped condition removes any uncerta>"nty associated with the new RTDs.
The staff finds the above administrative controls acceptable.
The licensee has also revised the T
value of the Technical Specifications from avg 570.5'F to 570.4'F (4 loop operation at Rated Thermal Power).
This change is insignificant for the accident analysis of concern and the change to the Technical Specification is acceptable.
~-
The licensee's proposal to add a note to page 3/4 3-22 to allow rod drop testing, rod position indication calibration, and hot zero power physics (above P-12) until the cross calibration results are available at the beginning of cycle is tentatively acceptable pending the licensee's development of a suitable Technical Specification on these tests under the section "Special Test Exceptions."
This new Technical Specification has been discussed with the licensee and is requested to clarify and simplify the Technical Specifications.
The proposed Technical Specification should be implemented before the beginning of the next fuel cycle (Cycle 10) and without the T
coincident channels in the tripped condition.
avg
Cj'INAL OETERMINATIOH -
NO SIGNIFICANT HAZAROS OETERMIHATION I
In our review of the revised setpoints in the channels for overpower delta T,
l overtemperature delta T, and loss of flow trips and the reactor coolant temperature to protect against departure from nucleate boiling and in our revie~ of the commitment to trip the low-low T channels for Cycle 9 startup testing, we have avg determined that the licensee has used acceptable methods and procedures and that the revision of setpoints and insignificant change in T v will assure that the existing safety analyses for the D. C., Cook Unit No.
1 are unchanged..
The revision to the setpoints has been analyzed with acceptable setpoint methodology.and will be accomplished with established procedures.
The setpoint methodology is capable o$ accounting for greater instrument uncertainty such that the instrument setting will produce the desired signals assumed in the safety analysis and to the extent other uncertainties are not changed by the resetting of setpoints, the safety analysis remains unchanged and valid.
The change'n T
of O. 1 F is so small as to avg be undetected in the safety analysis calculations.
The results of calculations would not change as a result this 0.1 F difference.
The comnitment to place the low-low T channels in the tripped condition was made when it was thought that avg the T change would be greater.
In any respect, the tripped condition avg although not significant because of the 0. 1'F change in T does assure without avg question that the steam line break analysis is unchanged.
The proposed amendment does not change the previous safety analyses and therefore does not change the consequences or probabilities of accidents previously evaluated.
The revision of setpoints in accordance with the approved setpoint methodology will assure that the desired signal is available as assumed in the safety analysis.
This change
is made to assure there is no reduction in the margin of safety.
Likewise the 0.1'F change in T is not discernible in the safety analysis results
- and, the avg proposed change is in keeping with the calibration and instrument settings.
There is no reduction in the margin of safety with this change.
The commitment to place the low-low T channels in the tripped condition will provide half of avg a signal to protect against main steam line break.
If the remaining half of the signal is received, the level of safety is maintained by the safety systems actuation to mitigate the steam line break.
This would not change the margin of safety and does result in actions which have been previously evaluated.
As with all of the proposed
- changes, we have determined that the amendment would not create the possibility of a new or different kind of accident from any accident previously evaluated.
On all of these
- bases, the staff has made a final determination that the proposed setpoints, T
, and test exceptions involve no avg'ignificant hazards consideration.
ENVI RONHENTAL CONS IOfRAT ION This amendment involves a change in the installation or use of a facility component located within the restricted area as defined in 10 CFR Pai t 20.
The staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure.
The Coranission has previously issued a proposed finding that this amendment involves no significant hazards consideration and there has been no public comment on such finding.
Accordingly, this amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR Sec 51.22(c)(9).
Pursuant to
0 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of this amendment.
CONCLUS ION Me have concluded, based on the considerations discussed above, that:
{1) there is reasonable assurance that the health and safety of the public will pot be endangered by operation in the proposed
- manner, J
and (2) such activities will be conducted in compliance with the Commission's regulations and the issuance of this amendment we'll not be inimical to the common defense and security or to the hea'1th and safety of the public.
Dated:
September 3, lgQ5 PRINCIPAL CONTRIBUTORS:
J.
Mauck J.
Guttmann D. Migginton