AECM-89-0030, Responds to NRC Bulletin 88-007,Suppl 1, Power Oscillations in Bwrs. Off-Normal Emergency Procedure 05-1-02-III-3, Decrease in Recirculation Sys Flow Rate, Changed to Incorporate BWR Owners Group Recommendations

Responds to NRC Bulletin 88-007,Suppl 1, Power Oscillations in Bwrs. Off-Normal Emergency Procedure 05-1-02-III-3, Decrease in Recirculation Sys Flow Rate, Changed to Incorporate BWR Owners Group Recommendations

ML20235S904
Person / Time
Site:	Grand Gulf
Issue date:	02/27/1989
From:	Cottle W SYSTEM ENERGY RESOURCES, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
AECM-89-0030, AECM-89-30, IEB-88-007, IEB-88-7, NUDOCS 8903080062
Download: ML20235S904 (4)

Text

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REEOtMCEE,INC.

we. swm uma. como.nv February 27, 1989

$7[m U.S. Nuclear Regulatory Commission Mail Station P1-137 Washington, D.C. 20555 Attention: Document Control Desk Gentlemen:

SUBJECT:

Grand Gulf Nuclear Station Units 1 and 2 Docket Nos. 50-416 and 50-417 License No. NPF-29 NRC Bulletin 88-07, Supplement 1:

Power Oscillations in BWRs AECM-89/0030 On-January 4, 1989, System Energy Resources, Inc. (SERI) received NRC Bulletin (NRCB) 88-07, Supplement 1: Power Oscillations in Boiling Water Reactors (BWRs). The purpose of the supplement was to provide additional information concerning power oscillations in BWRs and to request addressees to take action to ensure that the safety limit for the plant minimum critical power ratio (MCPR) is not violated. SERI's response to the bulletin action items are attached.

Yours truly, w r &--

WTC:mcg Attachments cc: Mr. T. H. Cloninger (w/a) Mr. H. L. Thomas (w/o)

Mr. R. B. McGehee (w/a) Mr. H. O. Christensen (w/a)

Mr. N. S. Reynolds (w/a) a Mr. Malcolm L. Ernst (w/a)

Acting Regional Administrator J8c4 c a. U.S. Nuclear Regulatory Commission

,98 Region II 101 Marietta St., N.W., Suite 2900

Q Atlanta, Georgia 30323

'$b gg Mr. L. L. Kintner, Project Manager (w/a) me Office of Nuclear Reactor Regulation

@ U.S. Nuclear Regulatory Commission '

OM Mail Stop 14B20 yM/

" To@c Washington, D.C. 20555 cauc cw a c w sw m e o wm l m ceamssam mo l mye J

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'S AFFIDAVIT STATE OF MISSISSIPPI ,

, COUNTY OF HINDS W. T. Cottle, being duly sworn, states that he is Vice President - Nuclear

' Operations, of System Energy Resources, Inc.; that he is authorized on the part L of said Company to sign and file with the Nuclear Regulatory Commission this ,

response to NRC Compliance Bulletin No. 88-07, Supplement 1 on behalf of the Company and South Mississippi Electric Power Association; that he signed the foregoing letter as Vice President - Nuclear Operations, of System Energy Resources, Inc.; and that the statements made and the matters set forth_therein are true and correct to the best of his knowledge, information and belief.  !

w? h W. T. Cottle SUBSCRIBED AhD SWORN T0 before ge, a Notary Public, in and for the County and State above named, this .Q '7fL day of ph , 1989.

(SEAL)

J Notary Public

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i My commission expires:

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Attachment to

- AECM-89/0030 Response to NRCB 88-07, Supplement 1

1. Operating Reactors (GGNS Unit 1) -

A. Item 1:

Within 30 days of receipt of this supplement, all BWR licensees should implement the BWR Owners' Group (BWROG) interim stability-recommendation described in Attachment 1 of the supplement. However, for those plants that do not have effective automatic scram protection in the event of regional oscillations, a manual scram should be initiated under all operating conditions when two recirculation pumps trip (or "no pumps operating") with the reactor in the RUN mode.

Response

Off-Normal Emergency Procedure (0NEP) 05-1-02-III-3, Decrease in Recirculation System Flow Rate, has been changed to incorporate the BWROG interim stability recommendations described in Attachment 1 of the bulletin supplement. The ONEP has also been changed to require a manual scram under all operating conditions when both recirculation pumps trip and the reactor is in the RUN mode. However, the manual scram requirement is not applicable during normal pump upshifts from low speed to high speed or downshifts from high speed to low speed.

B. Item 2:

The boundaries of Regions A, B, and C shown ir, Figure 1 of the BWROG recommendations were derived for those BWRs using NRC approved GE fuel. For BWRs using fuel supplied by other vendors, these regions should be adopted in principle, but the power / flow boundaries should be based on existing boundaries that have been previously approved by the NRC. For proposed new fuel designs, the stability boundaries should be reevaluated and justified based on any applicable operating experience, calculated changes in core decay ratio using NRC approved methodology, and/or core decay ratio measurements. There should be a high degree of assurance that instabilities will not occur under any circumstances of operation in Region C.

Response

Since Grand Gulf Nuclear Station (GGNS) is using Advanced Ncclear Fuels (ANF) fuel as well as GE fuel, the boundaries for Regions A, B, and C are based on existing boundaries that have been previously approved by the NRC and reflected in Technical Specification Figure 3.4.1.1-1. These regions are reflected in ONEP 05-1-02-111-3.

A Proposed Change to the Operating License (AECM-88/0251) was submitted December 19, 1988 to support reactor operation in accordance with the BWROG recommendations for core stability. This amendment is currently under review by the NRC.

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L  :. Attachment to

% 9 .,' . AECM-89/0030 C. Item 3:

The BWROG recommendations. of Attachment 1 are ambiguous with' respect to permissible conditions for entry of Regions B and C. Although the recommendations state that intentional-operation in Region B is not permitted and operation in Region C_is permitted'only for purposes of-fuel conditioning during rod withdrawal startup operations, intentional entry into Region 6 or C is also allowable.in_ situations-where rod insertion or a flow increase is required by procedures to-exit Regions A and B after. unintentional entry. Licensees should ensure that the procedures and training employed for implementation of these recommendations' avoid any similar ambiguity which could _ lead

-to operator confusion.

Response

Integrated,0perating Instruction (101) 03-1-01-2 specifically identifies permissible conditions for entry into Regions B and C.

101 03-1-01-2 and ONEP 05-1-02-III-3 are part of the continuing licensed operator's training program to ensure that licensed personnel are made aware of the recently encountered stability concerns and -

actions taken to prevent such problems from occurring at GGNS.

2. Construction Permit Holders (GGNS Unit 2) -

A. I_ tem 1:

All-construction permit holders should_ complete the' requested actions of the supplement before the'date scheduled for fuel load.

Response

NRCB 88-07, Supplement 1 action items will be tracked in SERI's commitment tracking. system as open items to be completed prior to Unit 2 fuel load.

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