ML13330B427
| ML13330B427 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 11/10/1988 |
| From: | Medford M Southern California Edison Co |
| To: | NRC Office of Administration & Resources Management (ARM) |
| References | |
| NUDOCS 8811170170 | |
| Download: ML13330B427 (3) | |
Text
Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD, CALIFORNIA 91770 M.O.MEDFORD TELEPHONE MANAGER OF (818) 302-1749 NUCLEAR REGULATORY AFFAIRS November 10, 1988 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 Gentlemen:
Subject:
Docket No. 50-206 Transshipment San Onofre Nuclear Generating Station Unit 1 In order to ship spent fuel at San Onofre Unit 1, it is necessary to use the turbine gantry crane. This has been described in various submittals, the latest being April 25, 1988 and April 28, 1988. As part of this use and provided in the description of the turbine building, the use of the crane has been limited in certain locations of the turbine building. This is the result of the turbine building being analyzed with the crane on the south end only for the seismic reevaluation program. The use of the crane was not considered to be a normal load during plant operation. Therefore, guidance on the use of the crane was developed to ensure its time is limited in a location outside the seismic design of the turbine building. This led to the following 1% per year use.
The 1% time is recorded when:
A. The crane is on the north extension with or without a load during plant operation (Modes 1-4).
B. The crane is on the north extension during a plant outage (Modes 5 and 6) with a load exceeding 10 tons.
C. The crane is south of the north extension with a load greater than 35 tons during plant operation (Modes 1-4).
Details surrounding the development of the 1% per year use are provided on pages 24 through 26 in the April 25, 1988 submittal on transshipment and on pages 7 through 9 in the April 28, 1988 license amendment.
The purpose of this letter is to identify the need to use the crane in the locations outside the seismic design of the turbine building. As indicated in the April 28, 1988 submittal, the crane is not normally used during plant operation. During shutdowns and refuelings, the crane is used to support the outage. The 1% per year time limit is expected to be used almost entirely during plant shutdown. This time will be used during spent fuel shipments
.1117C170-P Pri.4
Document Control Desk November 10, 1988 when the crane is loaded with the spent fuel cask on the north extension of the turbine building, such that, the majority of the 1% per year time limit is expected to be used on spent fuel shipment during Modes 5 and 6.
Other loads will also need to be carried by the crane in locations outside the turbine building design basis during shutdowns to support outages. As an example, to provide for the cleaning of the refueling cavity water, three casks exceeding 10 tons will be used. The purpose for this cleaning is to maintain water clarity in the refueling pool to perform the refueling operation. Equipment required to inspect the control rod drive mechanism split pins weighs in excess of 10 tons and is required for use inside containment. While the crane is carrying these loads over the north extension, the 1% per year time limit will be used. These loads will be moved during Modes 5 and 6. Typically, equipment required to support activities during outages and refuelings that is in excess of the loads set by the 1% per year time limit is moved-by the crane during plant shutdowns (Modes 5 and 6).
As indicated in the April 28, 1988 submittal, the crane is not normally used during plant operation (Modes 1 through 4).
This letter identifies loads to be moved by the crane during the 1% per year time limit for the Cycle 10 refueling outage. As indicated, these loads will be moved during Modes 5 and 6. The spent fuel shipments will only occur during Modes 5 and 6. There may be other loads required to support future outages and refuelings, but those loads are not known at the present. Every effort will be made to carry the loads by the crane during Modes 5 and 6.
Notwithstanding this, we do not intend to preclude use of the crane during Modes I through 4 in the event it is essential. During plant operation the crane will be located on the south extension of the turbine building.
However, its use will not be prohibited in areas outside the design basis during Modes 1 through 4 when it is needed to support plant maintenance activities required to be done during operation. Examples of loads that have been moved by the crane during plant operation in the past are the following.
About two years ago during plant operation the turbine gantry crane was needed to carry the materials for the repair of the spent fuel building roof. The crane would pick up material and equipment on the south end of the turbine building, bring it to the north extension in the vicinity of the spent fuel building, lay the materials down, and return to the south end. The crane was also used on the north end during plant operation to assist in the repair of the spent fuel building roll-up door. A lifting device was required for the work and using the crane was necessary. The crane was on the north end for approximately 30 minutes during this activity. More recently measurements for the lifting yokes to be used for the spent fuel cask were taken with the crane on the north extension in the position for lifting the cask in the area of the decontamination pad.
Therefore, based on these needs a further limit of.1% will be imposed on the use of the crane during Modes 1 through 4 within the existing imposed 1%
limit. As indicated, this is to be utilized in the event it is necessary to move the crane onto the north extension deck with or without a load during plant operation. At this time, movement of the crane onto the north extension during Modes 1 through 4 is not planned. Before moving the crane during plant
Document Control Desk November 10, 1988 operation consideration will be given to whether the activity can be performed during Modes 5 and 6.
If you have any questions regarding this, please let me know.
Very truly yours, cc: J. B. Martin, Regional Administrator, NRC Region V F. R. Huey, NRC Senior Resident Inspector, San Onofre Units 1, 2 and 3