ML20236U144

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Application for Amend to License NPF-29,revising Tech Specs to Allow Changes to Div Power Supply for Two Isolation Valves.Exemption Request Re RWCU Sys Compliance W/Nrc Regulations Will Be Submitted Separately
ML20236U144
Person / Time
Site: Grand Gulf Entergy icon.png
Issue date: 11/25/1987
From: Kingsley O
SYSTEM ENERGY RESOURCES, INC.
To:
NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20236U146 List:
References
AECM-87-0233, AECM-87-233, NUDOCS 8712020312
Download: ML20236U144 (8)
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Text

{{#Wiki_filter:$ .[ EVETEM EMRGY ' QMR D Kit &Uv.JR vce nexm November 25, 1987 rma ormons q U. S. Nuclear Regulatory Commission  ! Washington, D. C. 20555 , Attention: Document Control Desk Gentlemen:

SUBJECT:

Grand Gulf Nuclear Station 

                                                           . Unit'l                                  .'

Docket No. 50-416 I License No.'NPF-29 RWCU Isolation Valves. Proposed Amendment to the Operating License (PCOL-87/12) AECM-87/0233 By letter dated October 28, 1987 (AECM-87/0201) System Energy Resources, Inc. (SERI) submitted a proposed amendment to the GGNS. Unit 1 Technical Specifications to support a design change to the divisional power supplies.for  ! reactor water cleanup system (RWCU) containment and drywell isolation valves.- ] ' The proposed changes were part of the corrective actions to resolve a design error which resulted in two redundant containment isolation valves sharing the same divisional power supply. This design error and its associated corrective actions were reported to the NRC in a SERI submittal dated August '28,(1987 and . discussed with NRC management at a meeting on September 15, 1987. ] 

                                                                                                     .a NRC staff review of the October 28, 1987 submittal resulted in concerns                   j regarding certain components of the RWCU and the code requirements prescribed              .j by 10CFR50.55a. These concerns were identified and discussed with SERI in early November. SERI met with the NRC on November 20 and. agreed.to . seek exemption to NRC regulations as part of several corrective actions to resolve NRC concerns.
                                                                                                     ]    l The purpose of this letter is to resubmit the proposed changes to the                     i technical specifications which would allow changes to the division power                       1 supply for the two isolation valves. The discussion'of the RWCU system compliance with NRC regulations is contained in an-exemption request' submitted-

_ ) under separate cover.  ; In accordance with the provisions of 10 CFR 50.4 and 50.30, the signed 1 original ~ of the requested amendment is enclosed and the appropriate. copies  ! will be distributed. The attachment provides the technical justification and discussion to support.the requested amendment. This amendment has.been. .. reviewed and accepted by the Plant Safety Review Committee and the Safety Review Committee- 41 8712020312 871125 'fm i PDR ADOCK 050 by n c eox 23070 [ MSONMS3m M330D gCDO m 600 __ a 

         .J37AECM87112201.- 1                                                                     I  l r

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t AECM-87/0233 Page 2 Based on the guidelines presented in 10 CFR 50.92, SERI has concluded that this proposed amendment involves no significant hazards considerations. Since the application fee of $150 in accordance with the requirements of 10 CFR 170.21, was submitted in the original submittal and supplement, SERI has determined that no application fee is required for the submittal.  ; 1 The NRC Staff's expeditious review of this matter is requested because the proposed changes are required for startup from the current refueling outage which is scheduled for January 6, 1988. You ruly, ( I l 

                                                   <     l        .

l ODK:rg l Attachments: 1. Affirmation per 10 CFR 50.30 ,

2. GGNS PCOL-87/12 cc: Mr. T. H. Cloninger (w/a)

Mr. R. B. McGehee (w/a) l Mr. N. S. Reynolds (w/a) 1 l Mr. H. L. Thomas (w/o) Mr. R. C. Butcher (w/a) j Dr. J. Nelson Grace, Regional Administrator (w/a) ' l U. S. Nuclear Regulatory Commission Region II l 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 7920 Norfolk Avenue Bethesda, Maryland 20814 i Dr. Alton B. Cobb (w/a) State Health Officer State Department of Health Box 1700 Jackson, Mississippi 39205 l J37AECM87112201 - 2 1 

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BEFORE THE UNITED STATES NUCLEAR REGULATORY COMMISSION-LICENSE NO. NPF . 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, 0. D. Kingsley, Jr., being duly sworn, sta'ted 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 r. Association I am authorized by System Energy. Resources, Inc.-Lto sign.and file i with the Nuclear Regulatory Commission, this application for amendment' of-the-Operating License of the Grand Gulf Nuclear Station; thatLI signed this - application as Vice President, Nuclear Operations of System-E rgy., Resources ,.- Inc.; and that the statements made and the matters set for , erein are~true-and correct to the best of my knowledge, information and e. f. l s. 

                                                                             "O. DV Kingfle ,

STATE OF MISSISSIPPI > COUNTY OF HINDS SUBSCRIBED AND SWORN T0 befo_,rg me, a Notary Public, in and for the County and State.above named, this c1 94. day of f7Remlec , 1987. (SEAL) 

                                                 " ~'

dub) O. f)' ll O 

                                                                                -Notary Public
        'My commission expires: '                     -

0 fJ37AECM87112201 i4 u- _ _ _ __

1 Attachment If I AECM-87/0233 l l A.- SUBJECT l

1. NPE-87/06 Design change to the Divisional Power Supply to j Reactor Water Cleanup (RWCU) Containment and j Drywell Isolation Valves
2. Affected Technical Specification i
a. Table 3.6.4-1, Containment and Drywell Isolation Valves -

page 3/4 6-34.

b. Table 3.8.4.1-1, Primary Containment Penetration Conductor l Overcurrent Protective Devices - pages 3/4 8-28 and 8-35. 1 B. DISCUSSION
                                                                                                  ..I
1. On July 29, 1987, during a review conducted for the annual UFSAR Update, SERI engineers discovered that two motor operated containment isolation valves on the RWCU pump suction line (G33F252-A and  ;

G33F004-A for containment penetration ~ number 87) used in series shared the same divisional power supply. This condition is contrary  ! to UFSAR Section 6.2.4.1.h which states that power operated valves used in series for containment penetration isolation are to be  ! designed such that no single event can interrupt motive power to both closure devices.

2. This event was reported in accordance with 10CFR50.73(a)(2)(ii)(B) .

and 10CFR50.73(a)(2)(v)(C) via letter from SERI to the NRC dated August 28, 1987 (AECM-87/0168) and designated LER 87-011-00. . i

3. The RWCU was being operated in the " post-pump" mode of operation at l the time of discovery which requires both isolation valves to be j open. The post-pump mode is normally used during reactor operation.  ;

In this mode reactor water is cooled prior to entering the RWCU pump to extend pump seal life. The RWCU pumps were secured after the i discovery and the inboard isolation valve was closed and deactivated j in accordance with action statement b of GGNS Technical Specification l 3.6.4. Until the design concerns are resolved, the RWCU will be j operated in the " pre-pump" mode where the reactor water goes directly - to the RWCU pumps prior to entering the heat exchangers. This mode  ! of operation conforms to the containment isolation requirements i described in UFSAR Section 6.2.4.1.h. l l 4. As partial corrective action to the design error, SERI committed to ) change the divisional power supply for the inboard isolation valve  ! (G33F252-A) from Division I power to Division II-power prior to operating the RWCU in the post-pump mode. Also, the divisional power supply for the outboard drywell isolation valve (G33F253-B) will be changed from Division II to Division I power in order to maintain s redundancy for isolation of drywell penetration number 366. These  ; changes will be indicated in Table 3.6.4-1 of the Technical Specifications by changing the valve designator suffix for G33-F252 from "A" to "B" and G33-F253 from "B" to "A". The changes are indicated in Table 3.8.4.1-1 of the Technical Specifications by l J14 MISC 871014 - 1 1 

     - - _ -       -                                                                               1

1 Attachment !! AECM-87/0233 swapping valve G33-F252 to breaker 52-1641-08 and valve G33-F253 to breaker 52-1511-24.

5. Figure 1 shows a simplified drawing of the RWCU in the post-pump mode of operation and the proposed changes to the divisional motive power for valves G33-F252 and G33-F253.
6. Discussions with NRC Staff in early November raised concerns regarding the compliance of the RWCU system components located upstream of valve F252. up to and including valve F253 with the requirements of 10CFR50.55a. The NRC Staff interpretation of the definition of reactor coolant pressure boundary and of 10CFR50.2 and 50.5Ea(c) requires the RWCU piping and components which make up the subject line to meet the Class 1 requirements of ASME Section III. As a result of a meeting held with the NRC on November 20, 1987 SERI proposed alternative measures to meet the underlying purpose of 10CFR50.55a and agreed to seek an exemption under 10CFR50.12.

SERI proposed the following action:

a. Augmented inservice inspections:

l 1) to include RWCU piping through valve G33-F253 in the Class 1 portion of the ASME Section XI ISI program,

2) adding piping supports to the Class 1 support population,
3) adding welds to the Class 1 program for volumetric -

and surface examination. l l 4) including the system pressure boundary through valve G33-F253 in the Class I hydrostatic test boundary, and

b. Performing an ASME Section III, Class 1 stress analysis for i piping through valve G33-F253.

l The system piping cannot be restamped as Class 1, since the piping was procured to Class 2 requirements, rather than Class 1. However, j the physical and chemical properties of the materials used for the piping and fittings for the Class 2 portions of the system in question meets the requirements for Class 1 materials. Valve G33-F253 was procured as an ASME Section III Class I component. Component welds were performed by Section IX qualified welders utilizing welding rods 4 which met Class 1 weld metal requirements. Overall, considering these factors as well as the performance of-Class-1 stress analyses and augmented inservice examination, the system pressure-containing components up to and including valve G33-F253 can, therefore, be considered essentially equivalent to ASME Section III Class 1 components. J14 MISC 871014 - 2 w______

Attachment II AECM-87/0233 Additionally, two'ASME Code Class 1 valves (F001 and F252)'are installed in the system piping between the reactor coolant system and the ASME Code Class 2 components. By virtue of the manner in which the system is operated (" post-pump" vs. " pre-pump"), one of the ASME Code Class 1 valves will always be closed. Furthermore, to provide added assurance that these valves are not inadvertently opened at the same time, SERI has committed to install an interlock to prevent opening one valve if the other is open. This interlock will provide backup to the existing procedural controls. C. JUSTIFICATION

1. The proposed changes to Tables 3.6.4-1 and 3.8.4.1-1 will reflect a change to the divisional power supply to containment isolation valve G33F252-A and drywell isolation valve G33F253-B in order to provide electrical redundancy between the inboard and outboard containment isolation valves.
2. The proposed design change will provide divisional motive power separation for containment isolation valves F252 and F004 and drywell l isolation valves F252 and F253. The proposed change is consistent with the containment isolation design requirements as described in UFSAR Section 6.2.4.1.

N0 SIGNIFICANT HAZARDS CONSIDERATION SERI has evaluated the proposed change and determined that the change does not involve a significant hazards consideration for the following reasons:

1. The proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated. The proposed modification will provide divisional power separation between the inboard and outboard containment isolation valves for penetration number 87 thereby decreasing the probability and consequences of an accident by providing a more reliable containment isolation function.

Also, SERI has proposed additional measures that demonstrate a close equivalency of the RWCU components located upstream of Valve F252 up to and including Valve F253 to ASME Code Class 1 requirements. It is the NRC interpretation of 10CFR50.2 and 50.55a(c) that these components should be considered part of the reactor coolant pressure boundary and as such should meet the requirements of ASME Code Class

1. The affected components currently meet ASME Code Class 2 requirements. The additional measures involve the implementation of .

an augmented inservice inspection program for the affected ' components. In addition, ASME Code Class 1 required stress ~ analyses will be performed for the piping through valve F253. Physical and chemical properties of the affected components were assessed and determined to meet ASME Code Class 1 material requirements. Valve F253 was procured as an ASME Code Class 1 component. Further, welds on these components were performed to ASME Code Class 1 requirements. J14 MISC 871014 - 3

U . 

 #                                                                        ' Attachment II:

AECM-87/0233< Based on these factors and'the additional. measuresFproposed,'the: affected components closely approximate the ASMELCodeiClass l' requirements. Further,:the RWCU system has certain inherent features that' contribute to the protection of the' reactor coolant system. -The affected components are separated from the' reactor coolant system by two ASME Code Class l' valves. By virtue of.the manner in which the-system is operated, one of these Class 1 valves will always be closed. Furthermore, an interlock will be installed in the~ system: during the current outage to provide added assurance that one valve is not opened while the other valve is opened. 'These two valves (F001 and F252) along with valve F253 receive.an automatic isolation signal from the RWCU leakage detection system which is designed to i detect abnormal leakage from the piping system. Based on additional measures being applied to the affected components. to achieve a close-equivalency.to ASME Code. Class.1 requirements and in view of special features-inherent to RWCU operation and design, it can be concluded proper protection' of the reactor coolant system and reactor coolant pressure boundary is provided by'this system.. Therefore the proposed changes do not involve a significant increase in the probability or consequences of an accident previously evaluated.

2. Theproposedchangedoesnot'creati.thepossibility'of,anewor different kind of accident previously evaluated because the change-conforms to the safety design bases for the containment isolation 1 system as described in the UFSAR. .The proposed change will provide I

containment and drywell isolation such that no single event. can-interrupt motive power to the respective ~ inboard and outboard 1 isolation valves. The additional measures to be implemented will ] provide a close equivalency-to ASME Code' Class 1. These measures in combination with other features of RWCU system design.and operation provide proper protection of the reactor coolant system.such.that the piping and components will function as designed to provide' reactor coolant pressure boundary isolation. Therefore, the proposed change does not create the possibility of a new or different accident from any previously analyzed.

3. The proposed change does not involve a reduction in a margin of safety because changing the divisional motive power supply for the containment isolation valve will continue to: 1) ensure'that the containment atmosphere will be~ isolated from the outside environment in the event of a release of radioactive material to the containment ~

atmosphere or pressurization of containment and 2) ensure that thel drywell atmosphere will be directed to the suppression: pool' for the .i full spectrum of line breaks inside the drywell, respectively.  ; 1 J14 MISC 871014 - 4 , 

                                                                                            .4

Attachment 11 i 

                                                                                                                      'AECM-87/0233       ,

The physical and chemical properties of the affected components meet- q the ASME Class 1 requirements. Additionally, the augmented inservice.-  ! inspections and the ASME Class 1 stress analysis for RWCU piping l through valve G33-F253 will provide essentially equivalent components  ! to those specified by ASME Class 1. Additional features inherent to -{ the RWCU system contribute to protection of the reactor coolant system. Because proper protection to the reactor coolant system is provided, the proposed change does not involve a reduction in a margin of safety. l 1 l 4 I i 

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1 1 l 

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l i 1 l J14 MISC 871014 - 5 1 

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