ML19325D932
| ML19325D932 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 10/16/1989 |
| From: | Fay C WISCONSIN ELECTRIC POWER CO. |
| To: | Swenson W Office of Nuclear Reactor Regulation |
| References | |
| CON-NRC-89-127 GL-88-17, VPNPD-89-542, NUDOCS 8910270180 | |
| Download: ML19325D932 (3) | |
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. Wisconson E?Iecknc i
POWER COMhWY j
231 W M ohn:n Po Bom 2046. Mko#pe. WI S3201 (414)221 2345
' VPNPD 5 4 2 i
NRC 127 October 16, 1989 U.S.
NUCLEAR REGULATORY COMMISSION Document Control Deck Mail Station P1-137 l
Washington, D.C.
20555
' Attention:
Mr. Warren Swenson, Project Manager PWR Project Directorate III-3 r
Gentlemen:
DOCKET NOS. 50-266 AND 50-301 NRC OBSERVATIONS ON GENERIC LETTER 88-17 LOSS OF DECAY HEAT REMOVAL CAPABILITIES POINT BEACH NUCLEAR PLANT, UNITS 1 AND 1 Through Mr. Swenson's letter dated July 12, 1989, the NRC staff I
offered five observations regarding Wisconsin Electric Power Company's December 30, 1988, response to Generic Letter 88-17,
" Expeditious Actions for Loss of Decay Heat Removal."
Although the NRC staff had determined that our response meets the intent of the generic Ictter with respect to expeditious actions, it r
was suggested that we consider the cbservations addressed in the letter to assure that the actions of the generic Ictter are adequately addressed.
No response to these observations was required; however, we have recently completed additional calculations and felt it would be of benefit to comment on each of the five items.
I observation 1:
The December 30, 1988, response did not speci-fically state that maintenanco personnel are included in any of the training.
The-Point Beach Training Group completed a training needs analysis to determine who should be trained for reduced reactor coolant system (RCS) inventory considerations.
As a result of this analysis, it was determined that such training should be provided to maintenance superintendents and planners.
Training of these key people was determined to be the moct effective means of including the maintenance staff in the awareness of reduced RCS inventory considerations.
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Document Control Desk October 16, 1989 Page 2
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Observation 2:
The December 30, 1988, responso did not indicate if quick closure of the equipment hatch would be achieved by installation of a reduced number of bolts.
If this were the case, we would first have to verify that a proper seal of the periphery mating surfaces could be made to meet the closure criteria.
We do not plan to remove the equipment hatch during periods of reduced RCS inventory.
Observation 3:
The December 30, 1988, response indicated three types of 1cvel indication, but provided no accuracy of the readouts.
A calculation was performed which determined the accuracy of level indication from LT-447 to be +3% (+3 inches) when read from the computer and +3.6% when read Trom the level indicator on the control board!
The second method of level indication used for the current Unit 2 outage is a tygon tube which is monitored in the control room by means of a TV monitor.
The tygon tube uses the same taps as LT-447 and has markings on the monitor in 1 inch increments.
The readings are not alarmed.
The TV monitor was not used in Unit 1 because we were not aware at that time that the other indications identified in our response may not meet the intent of the Generic Letter with regard to accuracy.
Observation 4:
The December 30, 1988, response did not describe the additional injection paths for adding inventory to the RCS.
The concern is that under certain specific RCS condition, a hot leg injection path may be more effective than cold leg injection.
Procedure OP-4F, " Reactor Coolant System Reduced Inventory Requirements," indicates upper plenum (equivalent of hot leg) injection should be used if there is a cold Icg opening of I square inch or greater and there is no hot side vent available.
Observation 5:
The December 30, 1988, response did not state the use of any specific vent openings on the hot side of the RCS to relieve RCS pressurization.
Calculations needed to be performed to verify the effectiveness of the RCS openings.
Westinghouse performed calculations which verified the effective-ness of the RCS openings, including the removal of the pressurizer manway.
This calculation has been reviewed and approved by our staff.
Please note that Wisconsin Electric has completed certain additional calculations committed to be done in our previous response.
First, we have considered the effect of having a four region core, which we presently utilize, in relation to the three
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' Document Control Desk October 16 1989 Page 3 L
Io region core which Westinghouse assumed in WCAP-11916, " Loss of'
.I RHRS Cooling While the RCS is Partially Villed." The four region core decay heat rate at Point Beach has been confirmed to be i
enveloped by'the.WCAP calculations.
Second, the WCAP analysis i
assumed a 60. foot elevation difference between the mid-loop level and RWST. level for gravity feed.
At Point Beach, we have an elevation difference of about 41 feet..Again, the results of the calculation confirm that Point Beach is enveloped by the WCAP calculations.
t We trust this information will prove useful to you.
Very truly yours,
(
l gft</ 4 C. W.
ay Vice President Nuclear Power i
't Copy'to NRC Regional Administrator, Region III 7
NRC Resident Inspector t
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