ML19209C396

Forwards Request for Addl Info Re Plant Control Bldg Design Mods.Encl Questions Comprise NRC Positions Re Acceptable Util Response

ML19209C396
Person / Time
Site:	Trojan File:Portland General Electric icon.png
Issue date:	09/27/1979
From:	Lainas G Office of Nuclear Reactor Regulation
To:	Schwencer A Office of Nuclear Reactor Regulation
References
NUDOCS 7910150274
Download: ML19209C396 (3)

Text

,i C.,

UNITED STATES y

,-n /, g NUCLEAR REGULATORY COMMISSION E

WASHINGTON, D. C. 20555 5

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os, SEP 2 71979 MEMORANDUM FOR:

A. Schwencer, Chief, Operating Reactors Branch #1, DOR FROM:

G. Lainas, Chief, Plant Systems Branch, DDR

SUBJECT:

SAFETY EVALUATION OF DESIGN MODIFICATIONS TO THE CONTROL BUILDING - TROJAN NUCLEAR PLANT (TAC 7551)

Due to the indicated urgency in preparing the Plant Systems Branch's input to the Trojan Control Building modification safety evaluation, we took sev'r:1 positions in our portion of the safety evaluation that Portland Gene, al Electric (PGE) has not gone on record as agreeing to. Therefore, we wil? require a response from PGE indicating they will comply with these positions.

Attached, in the fonn of questions, are the positions that we will require an acceptable response from PGE.

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/ G. Lainas, Chief Plant Systems Branch Division of Operating Reactors

Enclosure:

Request for Additional Information cc w/ enclosure:

D. Eisenhut B. Grimes J. Knight R. Ferguson E. Adensam F. Clemenson C. Tramell J. Gray 1146 323 i

L 7910150,7

ADDITIONf3 INFORMATION REQUIRED ON TROJAN CONTROL BUILDING MODIFICATIONS TAC 7551 l.

Verify that the installed Hexcel energy absorbing material will be a)

" stabilized" in order to ensure the edge material is stabilized and therefore will absorb the anticipated amount of energy should it be crushed by a falling plate b) "precrushed" in order to eliminate t:.e peak load shown in Figure V-2 of Hexcel catalog #TSB-120 2.

Previous responses have indicated, in response to the control of dust, grit and debris that the work area may be isolated.

In this regard, the staff believes a small portable enclosure should be employed on the east and west inside walls of the control room and the electrical auxiliaries room when drilling holes in the walls. This box shall be capable of containing and collecting any dust, dirt, debris and water that may enter the room as the drill penetrates the wall.

Verify that such a small enclosure and collection means will be provided in order to preclude the release of this material inside the recms.

3.

Confirm that the required control room differential pressure requirements (Technic 31 Specification 4.7.6.1.d.3) can be maintained with a single open drilled nole in the control room wall.

Provide the basis for your conclusion.

Also, confirm that each hole will be temporarily plugged after being drilled.

4.

In reference to the use of wooden fonns for concrete work, the staff believes that a fire watch is required in safety-related areas where wooden forms are used. This fire watch will be required to tour the above ssfety-related areas at hourly intervals and shall be instituted when form construction begins and continue until the forms are removed. This fire watch will not be necessary during the times when a continuous watch has been established in an area for other purposes.

Verify that the above fire watch requirements will be complied with.

5.

In reference to the construction noise levels in the control room, response 18 to the staff's July 20, 1979 questions, you indicated that "Should it be detennined by the plant operator in the Control Room that excessive noise is being created, lighter weight tools or other means of concrete removal

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will be employed".

T'. staff believes it is essential that if either the NRC IE resident inspector or the plant operator should determine that excessive construction noise is being created, lighter weight tools or other means of concrete removal will be employed.

Verify that the above additional control on control room noise is acceptable and will be complied with.

6.

Presently it is proposed to utilize a positive feed control drill on the east and west control building outer walls. Further a person will be stationed on the inside for the purpose of detecti1g when the wall has been penetrated and notifying the driller via radio communications or by sound or battery powered telephones. Describe and discuss any other additional measures that can and will be imp 1 mented to further provide assurance the drill will not be allowed to pene ste to such an extent as to damage equipment within, e.g., positive stops or a paint strip on the core drill to alert the driller that wall penetration is imminent.

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