ML20128E041

Provides Tentative Positions on Facility Review Items Concerning Plant Design.Comments Requested

ML20128E041
Person / Time
Site:	Monticello
Issue date:	01/17/1969
From:	Boyd R US ATOMIC ENERGY COMMISSION (AEC)
To:	Morris P US ATOMIC ENERGY COMMISSION (AEC)
References
NUDOCS 9212070456
Download: ML20128E041 (3)

Text

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%,"n * / January 17, 1969 P. A. Morris. Director, RL TENTATIVE POSITIONS ON MONTICELLO REVIEW ITEMS (DOCKET No. 50-263)

Listed and discussed below are a number of changes which we believe should be incorporated in the Monticello plant design. The purpose of this memo-randum is to inform you of the position we believe we should take with respect to these items. We request your comments in this matter at this time since we plan to hold our first technical meeting with the applicant on January 23, 1969, and would like to work toward resolution of these items in a timely manner.

1. ECCS Pump Flooding 4

The Monticello plant is not provided with any means to accommodate flooding of the ECCS pumps in the reactor building as a result of a leak or rupture in the ring header or torus. This issue has been discussed and resolved during the construction permit review of a number of BWR plants. In some plants the ring header originally specified has been deleted and replaced with singic suction lines to each of the ECCS pumps. In addition, pro-vision is made to supply raw water to the core through a tie-in with the RHR service water rystem. In Oyster Creek the ECCS pump compartments were waterproofed, and all penetrations into these compartments made watertight.

The Monticello plant already has a ring header installed. Since a singic point failure in the ring header or torus could defeat the entire ECCS, we believe that the design of the Monticello plant should be modified to accommodate possible flooding of the ECCS pumps.

2. De-icing of Intake service Water System in the FSAR very sketchy information is provided on a de-icing system con-sisting of a pipe line leading from the turbine condenser discharge to the intake structure apron. When temperatures approach the freezing point, relatively warm condenser effluent can be delivered through this line to prevent the formation of ice on the trash rack and traveling screens. Our concern is that this source of warm water is limited once the turbine has been tripped. In the event of an extended shutdown or a DBA, the various 9212070456 690117 /

PDR ADOCK 05000263 h PDR f

P. A. Morris Janua ry 17, 1969 service water pumps located in the intake structure are required to supply water for safe plant shutdown.

Since Monticello is located in one of the colder regions of the country, our position is that a reliable means of preventing ice formation of the vital service water intake systems should be provided for all operating conditions.

3. Auto-Relief Valves - System Lonic As a result of the Oyster Creek POL revit:w, the following changes were incorporated into the auto-relief syttem logic -

a. To prevent pressure " hangup" the. auto-relief valves will be actuated coincident with actuation of the core spray and LPCI pumps.

b. All four valves will open upon receipt of the actuation signal instead-

, of only three.

c. An interlock will be provided to prevent actuation unless a.c. power is available.

d. The coincident signals of reactor low-low water, high containment pressure and low HPCI and/or feedwater flow required to maintain the relief valves open has been changed. Only the former two coincident signals are required.

We believe that these changes are necessary and should be required for Monticello.

4._ Containment-Inertinn-As with other BWR plants currently being reviewed for a POL (Dresden 2 & 3, Quad Cities 1 & 2), the Monticello FSAR does not.specify inerting for the centainment. This was n' design change from the previously-reviewed PSAR.

Since this problem is common to all BWR's and is now being studied, the final resolution should be applicable to Monticello.

5. Electrical Equipment in' Accident Environment in the interim following issuance of' the Monticello construction permit,-

applicants have been requested to verify through qualification tests that

P. A. Morris January 17, 1969 all electrical equipment required to function in the combined accident environment , temperature, pressure, and humidity will be capable of doing so. An acceptable alternative is the use of equipment which has successfully undergone qualification testing in connection with other projects.

We believe that this requirement should also be applied to Monticello.

m R. S. Boydi Assistant Director for Reactor Projects Division of Reactor Licensing Distribution:

R. S. Boyd D. R. Muller D. B. Vassallo C. J. Hale N. Blunt Suppl.

RL Reading RPB-1 Reading F. Schroeder .

R. C. DeYoung R. Tedesco C. Long R. Ireland D. Knuth B. Grimes

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