ML20043C353

Application for Amend to License NPF-29,modifying Initial 900216 Request Re Implementation of Neutron Flux Monitoring, to Include More Specific Schedule of Activities to Be Performed by Reg Guide 1.97

ML20043C353
Person / Time
Site:	Grand Gulf
Issue date:	05/31/1990
From:	Cottle W SYSTEM ENERGY RESOURCES, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20043C354	List: ML20043C353 ML20043C358
References
RTR-NUREG-0737, RTR-NUREG-737, RTR-REGGD-01.097, RTR-REGGD-1.097 AECM-90-0051, AECM-90-51, NUDOCS 9006050096
Download: ML20043C353 (12)

Text

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' System RM3f" T'~~ Energy Me%"A" May 31, 1990 2"2^"'

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

SUBJECT:

Grand Gulf Nuclear Station Unit 1 Docket No. 50-416 License No. NPF-29 Modification of Regulatory Guide 1.97 Compliance Schedule for Neutron Monitoring; Proposed Amendment to the Operating License Condition 2.C(36)

PCOL-90/01, Revision 1 AECM-90/0051

References:

1) AECM-90/0038 dated February 16, 1990; Modification of Regulatory Guide 1.97 Compliance Schedule for Neutron Monitoring; Proposed Amendment to Operating License Condition 2.C(36)

2) NRC Letter dated April 5,1990 (MAEC-90/0080); License Amendment Request to Defer Installation of Post-Accident Neutron Flux Monitor System Energy Resources, Inc. (SER1! is submitting by this letter Revision 1 to the proposed change to Grand Gulf Nuclear Station (GGNS)

Operating License Condition 2.C(36), Attachment 1. The proposed change requests an extension to .the implementation date for neutron flux monitoring until the fifth GGNS refueling outage. This request is based on 1) the additional time required for the BWR Owners Group (,8WROG) to evaluate and develop a design criteria document to address the results of the NRC Safety Evaluation Report (SER) of January 29, 1990 for BWROG NE00-31558 and 2) the additional time required for SERI to evaluate and apply the results of the BWROG design criteria to the GGNS design approach and perform further GGNS specific evaluations for improving neutron monitoring range sensitivity.

A9003081/SNLICFLR - 1 9k0 9006050096 900531 '

PDR ADOCK 05000416 P PDC I

'h ') AECM-90/0051 l

.s page 2 This proposed change to Operating License Condition 2.C(36) modifies the j i initial request made on February 16,1990 (Reference 1) as a result of -

discussions-with the GGNS NRC Project Manager and NRC letter dated April 5, 1990 (Reference.2). Changes to the proposed request for amendment include a more specific, schedule of activities to be performed by the RG 1.07 ,

BWROG Subcommittee and SERI actions to address the application of BWROG 1 L.

developed design criteria and the. alternate approaches to obtaining range sensitivity. In addition, the Significant Hazards Considerations have been

modified to more closely address the deferral of the initially proposed GGNS excore design approach.

'In accordance with the provisions of 10CFR50.4 the original of the i requested amendment is attached and the appropriate copies will be  ;

L distributed. The attached OLCR-NL-90-01 provides the technical justification i and discussion to support the requested amendment. This request for amendment-has been reviewed and accepted by the GGNS Plant Safety Review Committee.

t Based on the guidelines present in 10CFR50.92, SERI has concluded that this  ;

proposed amendment involves no significant hazards.

Since this submittal provides current activities conducted to dste by i' SERI and the GE BWROG, this submittal will also serve as the GGNS Quarterly Neutron Monitoring System Status Report for the period through March 31, 199u.

Yours truly,  ;

l

@ Fom WTC:tkm

Enclosure:

Affirmation per 10CFR50.30

Attachment:

OLCR-NL-90-01 cc: Mr. D. C. Hintz (w/a) <

Mr. T. H. Cloninger (w/a)

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

Mr. N. S. Reynolds (w/a)

Mr. H. L. Thomas (w/o) i Mr. H. O. Christensen (w/a)

Mr. Stewart D. Ebneter (w/a)

Regional Administrator U.S. Nuclear Regulatory Commission Region II 101 Marietta St., N.W., Suite 2900 Atlanta, Georgia 30323 Mr. L. L. Kintner, Project Manager (w/a)

Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop 14B20 Washington, D.C. 20555 A9003081/SNLICFLR - 2 i

g .

BEFORE THE UNITED STATES NUCLEAR REGULATORY COMMISSION LICENSE NO, NPF-29

DOCKET NO. 50-416 IN THE MATTER OF MISSISSIPPI POWER & LIGHT COMPANY and SYSTEM ENERGY RESOURCES, INC.

and SOUTH MISSISSIPPI ELECTRIC POWER ASSOCIATION AFFIRMATION I, W. T. Cottle, being duly sworn, state that I am Vice President, Nuclear Operations of System Energy Resources, Inc.; that on behalf of System Energy Resources, Inc., and South Mississippi Electric Power Association I am authorized by System Energy Resources, Inc. to sign and file with the Nuclear Regulatory Commission, this application for amendment of the Operating License of the Grand Gulf Nuclear Station; that I signed this application 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 my knowledge, information and belief, c- l> F Carcar--

W. T. Cottle STATE OF MISSISSIPPI COUNTY OF CLAIBORNE l SUBSCRIBED AND SWORN T0 bef re me, a Notary Public, in and for the '

County and State above named, this <\ day of rm , 1990, l- (SEAL) d hb= kogh%

NotaryPubliQ My commission expires-  !

My commisdon Expim 4 1.1993 i l- A9003081/SNLICFLR - 4 I

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.,' Attachment to AECM-90/0051 q

OLCR - NL-90-01 Extension of Post-Accident Neutron Flux Monitoring Upgrade l Implementation Schedule I. SUBJECT Facility Operating License No. NpF-29; Operating License Condition +

2.C(36) - Emergency Response Facilities; Attachment 1, Item (c)(4).

II. DISCVSSION The proposed change extends the implementation date for installing or:

upgrading the neutron flux monitoring system until prior.to startup following the fifth refueling outage. The current license condition specifies that the Regulatory Guide (RG) 1.97 requirements for the neutron flux monitoring system be implemented prior to startup following the fourth refueling outage (Refer to Attachment I to NPF-29).

A. Recent Background on Actions Affecting Implementation of a RG 1.97 Neutron Monitoring System As committed in AECM-89/0013 dated February 6, 1989 (Reference 3).

SERI has been in the process of developing an excore neutron rwnitoring system to comply with GGNS Operating License Condition 2.C(36) by the fourth GGNS refueling outage (RF04). In the February j 6, 1989 submittal, SERI noted that a reduction in low end range of 10E-6% power would be necessary based on the GGNS design approach to install detectors on the external portion of the shield wall. On '

July 21, 1989 (Reference 4) the NRC approved the request to pursue an excore system, but requested that SERI consider other locations where the RG 1.97 power range can be met. The status of our actions to implement this system was discussed in the December 5, 1989 ,

neutron monitoring system quarterly status report (Reference 5).- In the status report, SERI provided additional details regarding the  ;

unsuitability of other excore detector locations for compliance to

• the RG 1.9710E-6% power low end range. The report also noted that SERI's current plans were to issue the contract for an excore neutron monitoring system in mid February 1990. L Concurrent with the above actions, SERI worked closely with the BWR Owners Group (BWROG) in development of.the BWROG Topical Report;

• NED0-31558 (Reference 1), which provided alternate requirements on neutron monitoring for RG 1.97. This topical report was submitted ,

by the BWR Owners Group to the NRC for review on April 1,1988. In support of the existing GGNS neutron monitoring system design, SERI submitted a GGNS plant specific design evaluation on compliance to i NE00-31558 on April 28, 1988 (Reference 2). As a result of the NRC's ongoing review of NEDO 31558, SERI also submitted on December 20, 1989 (Reference 6) a request for an operating license amendment extending system implementation until the fifth GGNS refueling outage (RF05). The request was based on the need to allow adequate time for SERI evaluation of the NRC resolution of this issue prior to issuance of a February 1990 neutron monitoring system .

purchase order. +

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Attachment to AECM-90/0051 5

Af ter lengthy evaluation..the NRC issued'their Safety Evaluation Report (SER) on NEDO 31558 (Reference 7) on January 29, 1990 - In this SER the NRC concluded that a Category 1 designation and a low ,

end range of 10E-6% power were appropriate as specified in RG 1.97.

• Therefore, the alternate requirements of NEDO 31558 were found to be unacceptable. Subsequently, on February 2, 1990 the NRC rejected SERI's request for the GGNS Operating License amendment of December 20, 1989 extending the implementation schedule until'RF05 I (Reference 8). The extension request was rejected based on SERI's i ability to issue an excore NMS system purchase order by mid-February 1990.

i On February 7, 1989 SERI and certain members of the BWROG RG 1.97 Neutron Monitoring Subcommittee met with the NRC Staff to discuss conclusions reached by the NRC in their SER for BWROG NEDO-31558.

As a result of the BWROG/NRC meeting the NRC provided certain i clarifications to the SER and the process for each licensee on implementation actions. Based on SERI's understanding of this meeting, the NRC clarified that: j

1) There are technical issues that' remain unresolved.. These include the lack of event definition for which to base 10CFR50.49 environmental qualification and for meeting the RG 1.97 specified low end range of 10E-6% power.

2) The NRC does not intend to impose additional requirements that result in the need to qualify beyond the DBA environment (i.e.,

no fuel melting).

3) The NRC will not prescribe the event to which neutron >

monitoring equipment must be environmentally qualified.

4) The NRC is aware of the potential difficulty in meeting the low I end range of 10E-6% power for excore sensors. This was  :

considered an issue for possible relaxation depending upon plant specific technical bases and equipment availability.

5) The NRC requested the BWROG to consider a generic response regarding development of proposed design criteria for complying '

with RG 1.97 and the Staff's SER.

In summary, the NRC Staff recognized that even though the NRC has  ;

reached a final position on RG 1.97 neutron monitoring, several design and implementation issues still existed which licensees should address. As a result, the BWROG RG 1.97 Neutron Monitoring Subcommittee has been tasked to develop appropriate design criteria. '

This action is discussed in BWROG 1etter to NRC dated 2/21/90 (Reference 9).

In a separate discussion with the GGNS Project Manager on February 7, 1990, SERI was requested to continue implementation of the RG 1.97 excore design for the fourth GGNS refueling outage (scheduled to begin October 1990). The GGNS excore system design ,

approach should also consider detector locations through or inside -

of the GGNS shield wall to further meet the 10E-6% low end power  :

range.

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T r ,

l Attachment to AECM-90/0051 h .

1 B.- Current Actions Unden ay by BWROG_and SERI;for Address _ing the ,

g -Rgl.97NMS_ Issue-Since the original submittal of the proposed amendment to the GGNS  ;

Operating License to defer the RG 1.97-neutron monitoring system

• until the fifth GGNS refueling outage (AECM-90/0038 dated February 16,1990), several actions have been underway to address this issue by the BWROG and by SERI. These actions are summarized .

below

1) Current BWROG Actions On' March 18, 1990 the general BWROG committee authorized the  ;

RG 1.97 Neutron Monitoring Subcommittee to proceed with j development of the design criteria (specification) which will  !

be applicable to both incore and excore neutron monitoring.

designs.' '

On April 10, 1990 members of the BWROG management met with the NRC to discuss the technical basis for the SER on NE00-31558.  !

At this meeting the NRC reaffirmed their position provided in ,

the SER for meeting the RG 1.97 guidelines.

On April 18, 1990 the BWROG Subcommittee met with [

representatives of General Electric on the design for the  !

incore Wide Range Neutron Monitoring System and with Gamma- -

Metrics for the excore detector design. At this meeting system design information was presented and discussed regarding

, approaches to complying with RG 1.97. These discussions involved key design issues such as meeting separation criteria- >

and addressing environmental qualification, power source design, and core flux profiles. The Subcommittee will compile known issues and establish a design specification which will l address the extent of compliance with RG 1.97.  :

On May 21, 1990, the NRC staff issued a response to the BWROG  !

letter of February 21, 1990 clarifying the NRC position on -,

~'

certain BWROG identified design issues (Reference 10). In this letter the NRC reaffirmed the BWROG action to continue '

development of a design document for generic BWR application.

The BWROG subcommittee will factor the NRC staff clarification into the BWROG design specification.

2) Current SERI Actions As a result of the recent NRC position reaffirming BWR neutron monitoring system designs to meet a range goal down to 10E-6% power, SERI has begun evaluating alternate excore design approaches which will comply with this sensitivity range, t

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l Attachment to AECM-90/0051 l SERI is currently working with Gamma-Metrics on an excore detector design which is expected to obtain a neutron monitoring sensitivity to 10E-6% power or better under hot vessel conditions. This design will use a smaller detector (approximately 24 inches long by 2.5 inches in diameter) placed horizontally or at a slight diagonal into the bio-shield wall.

This installation approach will require boring or cutting a 2.75 inch hole in the bio-shield wall up to the inner steel liner. Based on the expected increased sensitivity only one detector per channel (2 channels) will be required.

SERI is in the process of developing a system design specification which will accomplish this design approach. This GGNS specification will be evaluated against the design specification being developed by the BWROG when finalized. As discussed in Section Ill, SERI will notify the NRC of the design approach which is expected to more fully comply with RG 1.97 3r request exception to RG 1.97 based on specific design constraints and cost benefit results.

III. SERI ACTIONS TO FURTilER ADDRESS RG 1.97 NEUTRON MONITORING REQUIREMENTS SERI will perform or participate in the following actions to further address RG 1.97 requirements for implementation of a post accident neutron monitoring system for the fifth GGNS refueling outage. The proposed schedule is based on anticipated BWROG schedules and subsequent SERI actions. SERI will notify the NRC of any changes to this schedule in subsequent GGNS Neutron Monitoring Quarterly Status Reports.

Action Schedule

1) BWROG RG 1.97 NMS Subcommittee to develop draft July 1990 design specification for RG 1.97 incore and excore neutron monitoring systems.

2) BWROG to finalize and issue BWR RG 1.97 NMS design Sept 1990 specification for BWROG member usage.

3) SERI to review and apply BWROG design criteria to Nov 1990 current GGNS excore NMS design approach.

4) SERI to notify NRC of a design approach which is Dec 1990 expected to comply with RG 1.97 or request exception to RG 1.97 based on GGNS specific design constraints and cost benefit results.

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,' Attachment to AECM-90/0051 [

,- t IV. JUSTIFICATION 7 A. Proposed Development of RG 1.97 Neutron Monitorino Desion_ Criteria i (Specification) Based on NRC Safety _ Evaluation Report to NEbO-31558 l As discussed in Section II of this amendment request, several design  :

issues were raised in the February 7, 1990 NRC/BWROG meeting .

regarding the NRC conclusions provided in the SER on NEDO 31558. 'l During this meeting the NRC proposed that the BWR Owners Group i establish design criteria for complying with the NRC's SER. Such a ,

criteria document (specification) is currently under development by '

the BWROG RG 1.97 Neutron-Monitoring Subcommittee.  ;

SERI has been an active member of the RG 1.97 BWROG Subcommittee for review of neutron monitoring design requirements. As a BWR licensee and committee member, SERI believes that further development of the '

BWR design criteria (specification) is appropriate prior to l implementing this system on BWRs. While SERI committed to install ,

an excore neutron monitoring system at the fourth refueling outage '

for meeting RG 1.97, this action is considered necessary in order ,

(1) to establish appropriate GGNS design considerations for RG 1.97 on post accident neutron monitoring, and (2) to avoid imprudent ,

financial expenditures and resource commitments by SERI if current i GGNS design considerations are modified.

D. Evaluation of Alternats GGNS Excore Detector Location (sMor Meeting the RG 1.97 Low End Ra_nle .,

As discussed in the December 5, 1989 Neutron Monitoring System ,

Quarterly Status Report (Reference 5), SERI has actively pursued the  :

installation of an excore neutron monitoring system to satisfy r Operating License Condition 2.C(36), Attachment 1. This included preparing the' initial excore neutron monitoring system design criteria, environmental design criteria, penetration design specifications and overall system purchase specification. The GGNS design approach was similar to that installed by Pennsylvania Power ,

and Light for RG 1.97 on Susquehanna Steam Electric Station. [

f Detector sensitivity and monitoring range was expected to be comparable to that obtained by Susquehanna (10E-4% to 10E-5% power under hot vessel conditions). Given the conclusions reached by NEDO 31558 to only require a 1% low end range, this design approach was considered fully justified based on the existing GGNS design limitations.

In discussion with the GGNS NRC Project Manager for GGNS on February 7, 1990, SERI was requested to further evaluate alternate ,

locations for meeting the RG 1.97 low end range of 10E-6% power on ,.

GGNS. As noted in the December 5,1989 quarterly status report any detector locations different from those currently proposed would k result in more involved and complicated design and installation hardships. Under the relatively near term implementation schedule for the excoro system at RF04 (commencing October 1990), a new design approach is impractical based on the need to have issued an

• excore system purchase specification (external to shield wall design) in February 1990. .

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, Attachment to AECM-90/0051 O

V. SIGNIFICANT HAZARDS CONSIDERATIONS

.The proposed amendment would modify GGNS Operating License Condition 2.C(36) Attachment I to extend the implementation date of the RG 1.97 required neutron monitoring system for an additional outage (i.e., the fifth refueling outage). The system previously being considered for GGNS would have met all known design considerations of RG 1.97 except the low end range of 10E-6% power. The GGNS currently..

proposed system is expected to result in a low end range sensitivity of approximately 10E-4% power. This extension is requested based on 1) the GGNS application of design criteria document [ specification development by the BWR Owners Group for addressing the NRC']

s SER on under NEDO-31558, and 2) the additional excore system detector placement evaluation on GGNS for meeting the low end range requirements of RG 1.97.

In accordance with the requirements of 10CFR50.92, the following discussion is provided in support of the determination that no significant hazards are created or increased by the changes proposed in this amendment request.

1. No significant increase in the probability or the consequences of an accident previously evaluated results from this proposed change because:

a. Deferral of the proposed GGNS post accident neutron monitoring system during the fifth fuel cycle does not involve a significant increase in the probability of an accident y previously evaluated since the proposed system modification would not affeet reactor operation. The post accident neutron flux monitoring system provides post-accident indication of reactor power and does not provide any signals to actuate engineered safety features or to trip the reactor.

Furthermore, reactor trip signals from the present neutron flux monitoring system to the reactor protection system will not be l changed as a result of the installation of the proposed GGNS I

post accident neutron monitoring system.

b. The currently proposed GGNS post accident neutron monitoring system is expected to be within two decades of meeting the RG l 1.97 low end range of 10E-6% power. The intent of the 1st accident neutron monitoring system (as discussed in thi lanuary l 29, 1990 Safety Evaluation Report on NEDO 31558) is to -. ovide warning of possible events for returning the reactor to a critical state. Under anticipated design basis events once all rods have been inserted, retura to a critical state would not be expected. However, under hypothetical events where certain  !

rods would drift out or where fuel would undergo some state changes, the GGNS proposed system would provide 6 decades (10E-4% to 100% power) of power status information to the operator during the fifth fuel cycle.

Deferring an installation of the proposed system one cycle to A9003081/SNLICFLR - 10

r i- . Attachment to AECM-90/0051 y ..

allow for additional design criteria review and further system r- detector locations may provide a post accident monitoring system that is more reliable and having a greater operating  ;

range. .

The deferral of the currently proposed post accident neutron

monitoring during GGNS Cycle 5 does not cause the consequences  !

L of an accident previously analyzed to increase since the  ;

existing SRM/IRM system is expected to function during the '

L initial phase of an accident (including a LOCA) to indicate subcritical reactor power. Long term post-LOCA monitoring is

~

availabin through the APRM channels where operator action is-required at the APRM downscale alarm. In addition, other measures and indications can provide the operator with reactor power information as discussed below:

i. .The present control rod position indication system provides the reactor operator with information that all rods hre inserted.

ii. Qualified instrumentation such as reactor pressure, suppression pool temperature and safety relief valve ($RV) <

actuation provide the reactor operator with post-accident information for assessment of reactor power.

c. Under a potential event as considered by the NRC in their SER on NEDO 31558 dated January 29, 1990, the GGNS symptom based-l Emergency Procedures (EPs) would provide appropriate conservative ~ actions if reactor power can not be directly measured in a post-accident situation. The EPs contain action ,

steps which mitigate the symptomatic effects of design basis events (such as LOCA) and beyond design basis events (such as ATWS) along with potential degraded core events.

I: Therefore, the consequences of an accident previously evaluated will not be significantly increased by the absence of a post accident neutron flux' monitoring system during the fifth fuel cycle. .

2. This proposed change will not create the possibility of a new or .

different kind of accident than any previously evaluated because:

The neutron monitoring system previously proposed by SERI on GGNS for meeting RG 1.97 will provide supplemental post accident monitoring capability by providing additional operator information in order to perform further potential mitigative actions during an accident. Its installation will not preclude or prevent any I accident. As such, delaying the installation of the RG 1.97 post accident neutron monitoring system will not create the possibility of a new or different kind of accident. During the extension period, the existing SRM/IRM neutron monitoring system will remain l unchanged from the configuration that was previously evaluated in l the FSAR. The current GGNS neutron monitoring system has been evaluated under the events described in NE00-31558 and would be 1

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Attachment to AECM-90/0051 i

considered acceptable for operation under design basis considerations (See Reference 2). Therefore, delaying installation of the RG 1.97 post accident neutron monitoring system will not 4 create the possibility of a new or different kind of accident from i any previously evaluated.

p 4 L 3. This proposed change does not involve a significant reduction in the i margin of safety because:

The current GGNS margin of safety is established by the existing SRM/IRM neutron monitoring system and the shutdown margin of the control rod system. The post accident neutron monitoring system required by RG 1.97 provides additional information to the operator for responding to undefined post accident reactivity anomalies. The

!- proposed GGNS excore neutron monitoring sptem will provide neutron monitoring diversity and qualified instrumentation to 10E-4% power.

Deferral of this system to allow for further review of syttem design criteria and alternate detector locations for improving low end  :

range sensitivity is not significantly compromised since the '

existing SRM/IRM system will still be operational. ,

The design, function, and operation of the existing GGNS IRM/SRM neutron monitoring system will remain the same as that described in the UFSAR. No additional reactor protection trip functions will be  ;

performed by the RG 1.97 post accident monitoring system instrumentation. .EP actions are conservative with respect to the .

use of the NMS for verification that the reactor is shutdown. If not available during an accident scenario, operator actions are specified which will lead to safe reactor shutdown. Because these actions lead to a safe plant condition (reactor shutdown), the-margin of safety is not significantly reduced.

VI. REFERENCES

1) GE NE00 31558 Dated April 1, 1988; "BWR Owners Group Tropical Report Position on NRC RG 1.97 Rev. 3 Requirements for Post-Accident Neutron Monitoring System"

2) AECM-88/0083 dated April 28, 1988; GGNS Plant Specific Design -

Evaluation for NED0 3.558- ,

3) AECM-89/0013 February 6, 1989; RG 1.97 Neutron Monitoring System; Request for Commitment Modification

4) NRC letter dated July 21, 1989 (MAEC-89/0228) regarding Post Accident Neutron Flux Monitoring l 5)- AECM-89/0204 dated December 5, 1989 regarding the Quarterly Status Report for RG 1.97 Neutron Monitoring System.

6) AECM-89/0223 dated December 20, 1989; Modification AG 1.97 Compliance Schedule for Neutron Monitoring; Proposed Amendment to OL Condition 2.C(36)

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e-  ;.

7^ Attachment ts AECM-90/0051 f-

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7) 'NRC. letter dated January 29, 1990; issuing the NRC Safety Evaluation-Report on BWROG NEDO 31558 .

8) 'NRC1stter'datedFebruary2,1990;regardingdenial.of'SERI0.L' .

. amendment request of December 20, 1989.

k ,, 9)~ BWR Owners Group Letter (BWROG-9025/MFN-008-90) dated February 21, 1990 entitled " Position on NRC Reg.: Guide 1.97 Rev.- 3. Requirements

'for Post-Accident Neutron Monitoring System."

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10)' NRC letter dated May 21, 1990 to the BWROG entitled, " Position on the Reg. Guide 1.97, Rev.'3 Requirements for Post Accident Neutron Monitoring System".

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