ML20054L566
| ML20054L566 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 07/01/1982 |
| From: | Leasburg R VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| To: | Clark R, Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| 394, NUDOCS 8207080249 | |
| Download: ML20054L566 (3) | |
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V11tOINI A EL15CTHIC ann Pownit CO)11*ANY R scii>io xn, Vinoix A caest it. it. Leiunc uo July 1, 1982 YA4' E I'EA E N1DE N T N ;cLeam Ormasaisonas Serial 110: 394 11r. liarold R. Denton, Director PSEC/DPD/JPK: brc Office of lluclear Reactor Regulation Docket IJo. 50-339 U. S. Iluclear Regulatory Cor.uission License 11o. IlPF-7 Washington, D. C. 20555 Attention: fir. Robert A. Clark, Chief Operating Reactors Branch flo. 3 Division of Licensing Gentlenen:
SEC0llDARY PROTECT 10110F C011TAllit1EllT ELECTRICAL PEllETRATI0llS Il0RTH AilllA POWER STATION UllIT 2 IIRC letter to Vepco dated 8/3/79, " Staff Position on
References:
1.
Electrical Protection of Containcent Penetrations for florth Anna Power Station, Unit 2".
2.
IIRC letter to Vepco dated 11/30/79, " Clarification of Staff Position on Electrical Protection of Containuent Penetrations for llorth Anna Unit 2".
3.
Vepco letter to llRC dated 10/10/80, Serial flo. 823,
" Primary and Secondary Electrical Protection of Containment Penetrations for florth Anna Unit 2".
IIRC letter to Yepco dated 11/10/80, " Backup Overcurrent 4.
Protection Systen for the llorth Anna Power Station, Unit 2 Contai nnent".
5.
Vepco letter to llRC dated 2/19/82, Serial 110. 084,
" Secondary Protection of Containment Electrical Penetrations, llorth Anna Power Station Unit 2".
Vepco letter to llRC dated 3/15/82, Serial flo. 084A, 6.
" Secondary Protection of Contairnent Electrical Penetrations, llorth Anna Power Station Unit 2".
/ool 8207080249 820701 PDR ADOCK 05000339 P
~
vlNONA 1lMCHIC AG rOMH cOnm m fir. Harold R. Denton 2
The purpose of this letter is to bring to your attention several design changes and clarifications concerning the directives and connitaents contained within the above references. These changes and clarifications are outlined as follous:
1.
Reference 1 states that it is acceptable to use non-class lE seisaically qualified protective devices to provide the primary and backup overcurrent protection for penetration asseablies carrying non-class lE circuits.
Our design for the reactor coolant pump electrical penetration circuits involves the addition of scisnic and lE qualified backup relay cabir;ets and control circuits to trip the main 5 KV breakers in the event that the primary relays fail to operate.
It does not include seisnically bracing the 5 KV suitchgear or seisaically supporting the cable inside containuent. This design was approved by the NRC in Reference 4, and we are proceeding accordingly.
2.
Our subnittals for proposed protection on power and control circuits (Reference 3) utilized extensively the GE Type THED circuit breaker.
The GE THED breaker is no longer available with lE qualification and in its place we have substituted a pre-qualified Westinghouse HFB nolded case circuit breaker.
The HFB time vs current curves are conpatible with those of the THED. Also, due to space limitations, we have substituted an HFB nolded case breaker in place of the air circuit breaker and OD-6 protective units that were specified for several circuits in our proposed power circuit protection subnittal.
3.
We have substituted a Westinghouse HFB nolded case breaker in lieu of the OTS-70 anp fuses that were specified in Reference 3 for secondary protection on the pressurizer heater circuits.
4.
On an assortaent of power and control circuits we had specified five and ten aup THED breakers for the secondarj protective device (Reference 3). Since there are no lE qualified five and ten aup breakers, we will be utilizing OTS-5 amp fuses or Westinghouse Type HFB 15 aup nolded case circuit breakers.
5.
Soue power circuits that were subnitted as requiring secondary protection will be re-classified as "nornally de-energized". This information was subaitted in Reference 6.
6.
In Reference 3 we proposed 40 and 60 anp breakers for secondary protection of the full length rod lifter and gripper circuits.
During the engineering process we have detemined that primary and secondary fuses are currently existing on these circuits and, therefore, the proposed breckers are not required.
D NOW!A EMCTRIC up [WEH COMMY To fir. Harold R. Denton 3
In Reference 5 ue stated that we would install approximately thirty percent of the secondary protection during the first refueling outage. Ilot including the rod control circuits discussed in Iten 6, we have now terminated and tested thirty-seven percent of the circuits requiring secondary protection.
As required by your letter, Reference 2, we will subnit revised tabulations and time current curves to update the changes discussed above. We are available at your earliest convenience should additional infornation be requi red.
Very truly yours, w
d R. H. Leasburg cc: fir. R. C. DeYoung, Director Office of Inspection and Enfortement Division of Reactor Operations Inspection Washington, D. C. 20555 fir. Janes P. O'Reilly, Regional Administrator Office of Inspection and Enforcement Region II 101 f1arietta Street, Suite 3100 Atlanta, Georgia 30303 brc/2362