ML18052A660
| ML18052A660 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 08/19/1986 |
| From: | Berry K CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8608220134 | |
| Download: ML18052A660 (2) | |
Text
consumers Power POWERllWi
. NllCHlliAN'S PROlillESS
(
General offices: 1945 West Parnell Road, Jackson, Ml 49201 * (517) 788-1636 August 19, 1986
- Director, Nuclear Reactor Regulation US Nuclear Regulatory Commission Washington, DC 20555 DOCKET 50-255 ~ LICENSE DPR PALISADES PLANT -
FIRE PROTECTION - VERIFICATION OF ALLOWABLE DELAY BEFORE MANUAL ACTION IS REQUIRED FOR SAFE SHUTDOWN Kenneth W Berry Director Nuclear Licensing The NRC staff conducted a special safety inspection from July 28 to August 1, 1986 to determine the Palisades Plant compliance status with respect to 10CFR50.48 and 10CFR50 Appendix R.
During the exit meeting on August 1, 1986, the inspectors reported that, although previous Consumers Power Company letters indicated that entry into any fire damaged room, zone or area to attain Hot Shutdown was not required until at least one hour after a fire was reported, entry into the Traveling Screens and Pumps fire area to open a Fire Water/Service Water cross-tie valve within thirty minutes of the start of a fire in that area cou.ld be required to assure adequate coolant flow to the Emergency Diesel Generator (EDG).
The inspectors therefore requested Consumers Power Company to clarify this apparent anomaly.
This letter provides that clarification.
The following assumptions are made for a fire in the fire area of interest;
- 1) offsite power is lost, 2) all three Service Water Pump motors are damaged,
- 3) the Diesel Fire Pump is the only source of coolant, and 4) the Emer.gency Diesel Generator can only operate for thirty minutes without coolant flow before overheating.
Analysis described in Consumers Power Company letter dated June 4, 1985 shows that operation of an EDG is not necessary before 2.2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> after the loss of offsite power.
At that time it could be necessary to operate an EDG to supply power for a Charging Pump and thus keep the PCS at least 25°F sub-cooled.
If the postulated fire which damaged all three Service Water Pumps did occur, the loss of service water would be annunciated in the Control Room.
At the time offsite power is lost, the EDG's would automatically start and the emergency buses would be automatically loaded with equipment required for safe shutdown.
OC0886-0132-NL04 8608220134 860819 PDR ADOCK 05000.255 G
PDR l 'I
Director, _Nqclear Reactor Regulation Palisa~es Plant Verification of Allowable Delay August 19, 1986 2
Emergency Operating Procedure EOP-3, "Loss of Service Water", lists increasing temperature of equipment cooled by service water as a symptom of the Loss of Service Water event and instructs the operator to open up the cross-tie valves between the Fire Water and Service Water Systems and to oper~te the EDG's.
If access to either of the two cross-tie valves is not possible due to a fire, the loss of cooling water to the EDG's would be annunciated locally at the EDG (with backup annunciation in t~e Control Room), and the operators would shut down the EDG's.
At that point in the scenario, approximately 30 minutes after the fire was reported, the operators would still have at least 1.7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> to gain access to a Fire Water/Service Water System Cross-Tie Valve, open it and thereby restore cooling water to the EDG's, and re-start an EDG and a Charging Pump before PCS subcooling drops below 25°F.
Therefore, as assumed in the Palisades Safe Shutdown Analysis submitted to the NRC by Consumers Power Company letter dated July 10, 1986, entry into the Traveling Screens and Pumps fire area is not required before one hour after a fire is reported.
This information is being provided at this time to allow this potentially open item to be closed before issuance of the Inspection Report.
-efL~~~L ~
Ke~~:;~y Director._, Nuclear Licensing CC Administrator, Region III, USNRC NRC Resident Inspector - Palisades OC0886-0132-NL04