ML20080S358

Forwards Addl Info Re Fuel Assembly Liftoff,Schedule for Implementing Mitigating Measures for Intergranular Stress Corrosion Cracking & Dynamic Qualification of Equipment,Per 831004 Request.Info Will Be Incorporated Into FSAR Update

ML20080S358
Person / Time
Site:	Grand Gulf
Issue date:	10/14/1983
From:	Dale L MISSISSIPPI POWER & LIGHT CO.
To:	Harold Denton Office of Nuclear Reactor Regulation
References
AECM-83--0667, AECM-83--667, NUDOCS 8310180352
Download: ML20080S358 (6)

Text

J MISSISSIPPI POWER & LIGHT COMPANY Helping Build Mississippi P.O. BOX 1G40, JACKSON, MIS Sion e e r, o c c uo October 14, 1983 NUCLEAR PRODUCTION DEPARTMENT Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C.

20555 Attention:

Mr. Harold R. Denton, Director

SUBJECT:

Grand Gulf Nuclear Station Units 1 and 2 Docket Nos. 50-416 and 50-417 License No. NPF-13 File 0260/L-860.0 Request for Additional Information AECM-83/0667 In response to an NRC informal request for additional information received on October 4, 1983, Mississippi Power & Light Company (MP&L) is providing the enclosed information addressing the following issues:

1)

Fuel Assembly Liftoff 2)

Schedule for Implementing Mitigating Measures for Intergranular Stress Corrosion Cracking (IGSCC) 3)

Dynamic Quelification of Equipment Attachment I contains plant specific information. This information represents a change to the Grand Gulf FSAR and will be incorporated in the FSAR update scheduled for June, 1984.

Please contact this office if additional information is required.

Yours truly,

. F. Dale Manager of Nuclear Services JHS/JGC:lm Attachments:

1)

Fuel Assembly Liftoff 2)

IGSCC 3)

Dynamic Qualification of Equipment cc:

(See Next Page) 0 1I CB1 k!Oh 0 00 6

lember Middle South Utilities System p

PDR

AECM-83/0667

• E" MICCIICIPPI POWER Q Ll2HT COMPANY cc:

Mr. J. B. Richard (w/o)

Mr. R. B. McGehee (w/o)

Mr. T. B. Conner (w/o)

Mr. G. B. Taylor (w/o)

Mr. Richard C. DeYoung, Director (w/a)

Office of Inspection & Enforcement U.S. Nuclear Regulatory Commission Washington, D.C.

20555 Mr. J. P. O'Reilly, Regional Administrator (w/a)

U.S. Nuclear Regulatory Commission Region II 101 Marietta St., N.W., Suite 2900 Atlanta, Georgia 30303 CB2

~~

Attachmant 1 to AECM-83/0667 Page 1 of 2 ISSUE:

Provide the plant specific values determined using the methodology contained in NEDE-21175-3-P for the fuel = assembly acceleration due to seismic loadings.

(

Reference:

,GGNS License Condition, t

2.C(13).)-

RESPONSE

In letter AECM-82/371, dated August 30,'1982, MP&L submitted information endorsing.the General Electric Licensing Topical Report NEDE-21175-3-P. The plant specific fuel assembly values were determined using this topical report and are:provided in the attached table. This' table represents new information to be provided in the _ FSAR and will be included in the FSAR update scheduled for June, 1984.

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4 GG FSAR TABLE 3.9-2b (Cont.)

(vi) FUEL ASSE2LY (INCLUDING CHANNEL)

Calculated Peak Evaluation Basis Acceptance Criteria Loadi&1 Primary Load Type Acceleration Acceleration 1

Acceleration Envelope Horizontal Direction:

Horizontal Acceleration 1.5 G (1)

Profile 1.

Peak Pressure i

2.

Safe Shutdown i

Earthquake 3.

Annulus Pressuri-zation 2.3(4)

(1)

Vertical Direction:

Vertical Acce:arations l

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1.

Peak Pressure 2.

Safe Shutdown i

Earthquake l

3.

Safety Relief Valve 4.

Scram 4

i NOTES:

Evaluation Basis Accelerations and Evaluations are contained in NEDE-21175-3-P.

)

(1)

The calculated maximum fuel assembly gap opening for the most limiting load combination is 0.002(4g inch.

(2) j (3) The fatigue analysis indicates that the fuel assembly ha.s adequate fatigue capability to withstand the loads resulting from multiple SRV actuations and the OBE+SRV event.

(4) These values are determined using the methodology contained in NEDE-21175-3-P.

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' to AECM-83/0667 j

-Page 1 of 1 ISSUE:

Clarify intentions for the early implementation of mitigation techniquet for those welds susceptible to intergranular stress corrosion cracking (ICSCC).

RESPONSE: In letter AECM-83/0481, dated August 17, 1983, MP&L provided information pertaining to '.0 SCC for Grand Gulf. This submittal included a report which identified twenty-two (22) welds in the recirculation system piping susceptible to IGSCC. In addition, further evaluation has identified two (2) additional welds in the recirculation system piping that are also susceptible to IGSCC and should be subjected to mitigation techniques.

- MP&L considers that the delay in implementation of mitigation techniques on the subject welds until the first refueling outage has been adequately justified (AECM-83/0481). However, MP&L alto recognizes the technical merit of implementing these techniques as early as possible in plant life and is, therefore, aggressively pursuing the necessary equipment to accomplish this..MP&L intends to implement the required mitigation techniques as soon as practicable, on a schedule consistent with the plant's startup test program. As discussed with the NRC in a meeting held October 12, 1983, MP&L anticipates that mitigation techniques will be implemented in March and. April of 1984.. It should be noted, however, that this schedule is subject to the uncertainties of the startup test program and should not be considered as a formal commitment by PPAL to an accelerated implementation schedule, i.e.,

prior to startup from the first refueling cutage.

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Attcchment 3 to AECM-83/0667 Page 1 of 1 ISSUE:

Provide commitment for qualification dates for outstanding fuel handling equipment and BOP /PGCC panels.

(

Reference:

GGNS License Condition 2.C(11).)

RESPONSE: A status of these two items is provided below:

1) Fuel Handling Equipment All fuel handling equipment involved in the qualification test program has been fully qualified with the exception of a defective fuel canister. As stated in Supplement 3 to the Grand Gulf Safety Evaluation Report (NUREG-0831), this equipment is not required for use until the first refueling outage. MP&L contends that the qualification schedule should be consistent with the need for the equipment. Therefore, as stated in AECM-82/625, dated December 22, 1982, qualification of this equipment will be completed four (4) months prior to the first refueling outage and a confirmatory report will be provided by MP&L following the completion of qualification.

2) BOP /PGCC Panels All the devices involved in the BOP /PGCC qualification test program have been fully qualified with the exception of a Bourns Potentiometer. As committed to in AECM-82/625, testing of this device was completed prior to the beginning of Phase II operation. However, this device malfunctioned during the original test due to the accelerated aging techniques that were applied. A retest of this device is currently underway and will be completed by December 15, 1983. MP&L will submit the results of this retesting by December 31, 1983.

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