ML20040A882
| ML20040A882 | |
| Person / Time | |
|---|---|
| Site: | Wolf Creek, Callaway  |
| Issue date: | 01/19/1982 |
| From: | Petrick N STANDARDIZED NUCLEAR UNIT POWER PLANT SYSTEM |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0830, RTR-NUREG-830 IEC-81-12, SLNRC-82-05, SLNRC-82-5, NUDOCS 8201220266 | |
| Download: ML20040A882 (2) | |
Text
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,4 SNUPPS Standardized Ne.loor Unit Power Plant System Nicholas A. Petrick 5 Choke Cherry Road Executive Director Rockville, Maryland 20850 (301) e 0iG January 19, 1982 SLNRC 82 05 FILE: 0543
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SUBJ: Shunt Coils fora $iEE67-@ip
/
Breakers 4
r Mr. Harold R. Denton, Director 97 E
Office of Nuclear Reactor Regulation
_m JAN 31 jggg, U.S. Nuclear Regulatory Commission 3 w m y,,,,,_ g Washington, D.C.
20555 C.u gyr T-L
,y[js Docket Nos. STN 50-482 and STN 50-483 il[hs\\
References :
1.
NUREG-0830, Safety Evaluation Report -
y, October
- 1981, 2.
IE Circular 81-12, July 22, 1981.
Dear Mr. Denton:
Sections 7.2.2.5 and 16 of Reference 1 describe the NRC's intentions of re-quiring independent checks of the operability of the undervoltage and shunt trips of the reactor trip breakers. This planned technical specification apparently resulted from the incident described in Reference 2.
The SNUPPS i;tilities do not believe that such checks are necessary and, in fact, could be detrimental from a safety standpoint.
It would be prefer-able to remove the shunt trip coils rather than make this check. Westing-nouse, the SNUPPS NSSS supplier, concurs in this position.
No credit is taken for shunt coil circuits of the reactor trip breakers.
They are used only for additional assurance when the breakers are tripped with the manual trip switches at the control board.
Each breaker is auto-matically tripped by de-energizing the undervoltage coil through the solid state protection system (SSPS).
Independent dc power for two series-con-nected breakers is provided from the vital ac buses.
The breakers and associated undervoltage circuits are Class lE and meet all applicable criteria including on-line testability. Undervoltage coils are continuity tested
~
using the semi-automatic test features of the SSPS as well as a functional (actual opening) test through the SSPS in accordance with planned surveil-lance test requirements of the Technical Specifications.
Independent testing of the shunt circuits would require, as a minimum, jury-rigging of the breaker control circuits and/or the SSPS with the attendait
)
risk of damage or degradation of these Class 1E circuits. While it would be unfortunate to remove the shunt trip coil from the design, it would be Eod justified in order to avoid temporary modifications to safety circuitry in s
order to provide.
C 0201220266 820119 L PDR ADOCK 05000482 A
SLNRC 82 05 Page Two The NRC Staff is requested to reconsider this planned Technical Specifica-tion in light of the information provided above.
Prompt consideration of this matter will be appreciated.
Very truly yours, fhcU Nicholas A. Petrick RLS/jdk cc:
G. L. Koester KGE D. T. McPhee KCPL D. F. Schnell UE T. E. Vandel NRC/WC Resident Inspector NRC/ CAL t
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