View source for AECM-86-0225, Application for Amend to License NPF-29,combining Drywell Vacuum Relief Requirements for post-LOCA & Combustible Gas Purge Sys Into One Tech Spec.Fee Paid

{{Adams
| number = ML20207G502
| issue date = 07/16/1986
| title = Application for Amend to License NPF-29,combining Drywell Vacuum Relief Requirements for post-LOCA & Combustible Gas Purge Sys Into One Tech Spec.Fee Paid
| author name = Kingsley O
| author affiliation = MISSISSIPPI POWER &amp; LIGHT CO.
| addressee name = Denton H
| addressee affiliation = NRC OFFICE OF NUCLEAR REACTOR REGULATION (NRR)
| docket = 05000416
| license number = 
| contact person = 
| document report number = AECM-86-0225, AECM-86-225, TAC-60587, TAC-60588, TAC-60589, TAC-60590, TAC-60591, TAC-60592, NUDOCS 8607230085
| package number = ML20207G509
| document type = OPERATING LICENSES-APPLIATION TO AMEND-RENEW EXISTING, TEXT-LICENSE APPLICATIONS &amp; PERMITS
| page count = 10
| project = TAC:60587, TAC:60588, TAC:60589, TAC:60590, TAC:60591, TAC:60592
| stage = Request
}}

=Text=
{{#Wiki_filter:r a     .p MISSISSIPPI POWER & LIGHT COMPANY Helping Build Mississippi EulMdMdiddE        P. O. B O X 164 0, J A C K S O N, MISSISSIPPI 39215-1640 July 16, 1986 O. D. KINGSLEY, JR.
YlCE PRESIDENT-NUCLEAR OPERATIONS U. S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Washington, D. C.            20555 Attention: Mr. Harold R. Denton, Director

==Dear Mr. Denton:==

==SUBJECT:==
Grand Gulf Nuclear Station Unit 1 Docket No. 50-416 License No. NPF-29 File: 0260/0840/L-860.0 Proposed Amendment to the Operating License (PCOL-86/17)
AECM-86/0225 The attached proposed changes to the technical specifications for Grand Gulf Nuclear Station (GGNS) Unit I combines the drywell vacuum relief requirements for the post-LOCA and combustible gas purge systems into one technical specification.             In accordance with the provisions of 10 CFR 50.59 and 50.90, Mississippi Power & Light (MP&L) requests an amendment to License NPF-29, for GGNS Unit 1.
In accordance with the provisions of 10 CFR 50.30, three (3) signed originals and forty (40) copies of the requested amendment are enclosed. The attachment provides the complete technical justification and discussion to support the requested amendment. This amendment has been reviewed and accepted by the Plant Safety Review Committee (PSRC) and the Safety Review Committee (SRC).
Based on the guidelines presented in 10 CFR 50.92, it is the opinion of MP&L that this proposed amendment involves no significant hazards considerations.
In accordance with the requirements of 10 CFR 170.21, we have determined that the application fee is $150. A remittance of $150 is attached to this letter.
Yours    uly, 8607230085 860716 PDR      ADOCK 05000416 P                         PDR ODK:lwm                                               '                    '
f Attachments: GGNS PC0L-86/17 h
cc:      (See Next Page)
N J10AECM86071601 - 1             Member Middle South Utilities System      gcf c! u/

AECM-86/0225 Page 2 cc: Mr. T. H. Cloninger (w/a)
Mr.~ R. B. McGehee (w/a)
Mr. N. S. Reynolds (w/a)
Mr. H. L. Thomas (w/o)
Mr. R. C. Butcher (w/a)
Mr. James M. Taylor, Director (w/a)
Office of Inspection a Enforcement U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Dr.J.NelsonGrace, Regional'Administrat'or(w/a)
,          U. S. Nuclear Regulatory Commission Region II                   .
101 Marietta .it., N. W., Suite 2900 Atlanta, Georgia 30323 Dr. Alton B. Cobb (w/a) l          State Health Officerz State Board of Health Box 1700 Jackson, Mississippi 39205 i
i J10AECM86071601 - 2

BEFORE THE UNITED STATES NUCLEAR REGULATORY COMMISSION LICENSE N0. NPF-29 I
DOCKET N0. 50-416 IN THE MATTER OF MISSISSIPPI POWER & LIGHT COMPANY and MIDDLE SOUTH ENERGY, INC.
and SOUTH MISSISSIPPI ELECTRIC POWER ASSOCIATION AFFIRMATION I, 0. D. Kingsley, Jr. , being duly sworn, stated that I am Vice President, Nuclear Operations of Mississippi Power & Light Company; that on behalf of Mississippi Power & Light Company, Middle South Energy, Inc., and South Mississippi Electric Power Association I am authorized by Mississippi Power & Light Company 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 Mississippi Power & Light Company; and that the statements made and the matters set forth therein are true and correct to th est of my knowledge, information and belief.
a .       A         ~
                                                                          ~
STATE OF MISSISSIPPI COUNTY OF HINDS SUBSCRIBED AND SWORN T0 be               me, a No ar Pyblic, in and for the County and State above named, this                   ay of       c,&z              , 1986.
i (SEAL)
My commission expires:
My CommhWn Expires sep. 21. 1937 J10AECM86071601 - 4

1 NPE-85/16     (Additional Submittal)

==SUBJECT:==
Technical Specification 3/4.6.5, Bases 3/4.6.5 and Index; Pages 3/4 6-46, 3/4 6-47, B 3/4 6-7, 8 3/4 6-8, and Index viii and xiv.
DISCUSSION:   Mississippi Power & Light (MP&L) Company proposed changes to the subject technical specification in a letter from Mr. O. D.
;                                         Kingsley, Jr. to Mr. Harold R. Denton dated January 29. 1986 with a supplementary submittal on April 14, 1986. The requested changes were to allow implementation of a design change to add position indicators with redundant indication and alarm in the control room for the check valves associated with the drywell post-LOCA vacuum breaker system. Subsequent discussions with NRR staff have resulted in modifications to the previous submittals. These modifications are submitted in this letter and include the following:
: 1. The title of the subject specification has been changed to Drywell Vacuum Relief to indicate inclusion of the drywell vacuum relief subsystems associated with the Combustible Gas Purge System in addition to the present Drywell Post-LOCA Vacuum Relief System.
: 2. Limiting Condition for Operation 3.6.5 is modified to address operability of two drywell post-LOCA vacuum relief subsystems and two drywell purge vacuum relief subsystems.
: 3. Action requirement changes associated with the subject specification. include the following:
: a. Proposed Action a will allow one drywell post-LOCA vacuum relief subsystem and/or one drywell purge vacuum relief subsystem to be inoperable for opening i
but known to be closed for up to 30 days before i                                                    requiring plant shutdown,
: b. Proposed Action b will allow two post-LOCA vacuum relief subsystems to be inoperable for opening but known to be closed for up to 30 days before requiring
,                                                    plant shutdown, provided that both the drywell purge vacuum relief subsystems are operable.
i
: c. Proposed Action c will allow both of the post-LOCA vacuum relief subsystems and one of the drywell purge vacuum relief subsystems to be inoperable for opening but known to be closed for up to 72 hours before
;                                                    requiring plant shutdown.
: d. Proposed Action d applies the requirements of present Action b for open vacuum breakers to the drywell isolation vacuum breakers in the post-LOCA and purge vacuum relief subsystems.
!                           J10ATT86062401 - 1
: e. Proposed Action e applies the requirements of present Action c for position indication, to all the vacuum breakers and motor operated isolation valves in the drywell post-LOCA and purge vacuum relief subsystems. Plant shutdown requirements are proposed when associated valves cannot be verified to be closed.
: 4. Surveillance Requirement 4.6.5 is modified to include each post-LOCA and purge system vacuum breaker and associated isolation valve.
: 5. Bases 3/4.6.5 is rewritten to more accurately reflect the present design basis of the drywell vacuum breaker subsystems.
The design change associated with these proposed technical specification changes is scheduled for implementation not later than startup following the first refueling outage. As done on several technical specification changes involving design changes to the plant, it is requested that the NRC issue the change with an open effective date and require that MP&L notify the NRC within 30 days of the effective date of implementation of the affected technical specification changes.
JUSTIFICATION: Drywell vacuum relief following a postulated large break LOCA is provided by two drywell post-LOCA and two drywell purge vacuum relief subsystems. This vacuum relief function is provided only after a large break LOCA. An independent vacuum relief capability (normal drywell vacuum relief line) is provided by a separate system for normal operating transients and small pipe ruptures in the containment. The proposed technical specification changes discussed in this proposal are related only to the four drywell vacuum relief subsystems used after the postulated large break LOCA.
Three 10 inch lines penetrate the drywell so that containment air will have a flow path into the drywell and allow vacuum relief during a postulated large break LOCA. Two of the 10 inch lines are part of the Combustible Gas Control Purge System and the remaining 10 inch line is part of the Post-LOCA Vacuum Relief System. Each 10 inch vacuum relief line in the Combustible Gas Control System contains a drywell vacuum relief purge subsystem. Each of the two purge subsystems consists of a motor operated isolation valve and two check valves arranged in series. The motor-operated butterfly valves on each drywell vacuum relief purge subsystem inlet ifne are opened automatically when the drywell pressure falls to within one psid above the containment pressure after a LOCA. Vacuum relief will then initiate at a differential pressure across the check valves of one psi.
J10ATT86062401 - 2

The 10 inch drywell vacuum relief line that is a part of the Post-LOCA Vacuum Relief System contains two subsystems arranged in parallel. The subsystems are redundant in that operability of either one will ensure. operability of the associated 10 inch drywell post-LOCA vacuum relief line. Each drywell post-LOCA vacuum relief subsystem consists of a motor operated isolation valve and a check valve arranged.in series'. The motor-operated butterfly valves on each drywell ' post-LOCA vacuum relief subsystem inlet line are opened automatically when the drywell pressure falls to within one psi below that of the containment after a LOCA. Vacuum relief will then initiate at a differential pressure across the check valves of one psi.
Present Technical Specification 3/4.6.5 addresses the operability requirements of the post-LOCA vacuum breaker subsystems while Specification 3/4.6.7.3 addresses the operability requirements of the Combustible Gas Control Purge System. In researching the design requirements for the drywell vacuum relief function and through discussions with the NRC, MP&L has determined that Technical Specification 3/4.6.5 should be modified to include the vacuum relief functions.of the post-LOCA vacuum relief subsystems and the purge vacuum relief subsystems. No changes are required to Technical Specification 3/4.6.7.3 since this specification adequately addresses Drywell Purge System operability as presently written. Proposed changes to Technical Specification 3/4.6.5 will provide consistent application of requirements to all components used in the drywell vacuum relief function. Present technical specification requirements are not the same for all components performing a drywell vacuum relief function in the post-LOCA and purge'-
subsystems. However, all subsystems are tested and required to be operable by present technical specifications. Also present technical specifications do require an adequate number of vacuum relief subsystems to be operable to meet design assumptions.
The design basis for the drywell vacuum relief function is to-control rapid weir wall overflow in a large break LOCA that could cause drag and impact loadings to essential equipment and systems in the drywell above the weir wall. Present drywell negative pressure analysis for rapid weir wall overflow in a large br                                                        K=
0.38 ft.gak LOCA assumes   a vacuum   relief capability of A/
This relief capability requires a minimum of two 10 inch drywell vacuum relief paths out of the three installed.
Drywell vacuum relief is not required to assist in hydrogen dilution or to protect the structural integrity of the drywell following a large break LOCA. Proposed changes to Technical Specifications and Bases 3/4.6.5 are based on present design requirements for drywell vacuum relief.
The proposed changes as listed in the discussion section are justified as follows:
J10ATT86062401 - 3
: 1. The present title of Technical Specification 3/4.6.5 is proposed to be' changed to Drywell Vacuum Relief. This change reflects the addition of operability requirements for all systems that are available to perform a drywell vacuum relief function after a postulated large break LOCA.
: 2. The change to the Limiting Condition for Operation 3.6.5 is proposed to require operable, the four subsystems installed in GGNS Unit 1 for drywell vacuum relief following a postulated large break LOCA.
: 3. The proposed action statements are based on present design considerations and are justified below:
: a. Action a Proposed Action a specifies the steps that are to be taken with one of the drywell post-LOCA and/or one of the drywell purge vacuum relief subsystems inoperable for opening but known to be closed. While in this Action Statement provisions, a maximum of one of the three 10 inch drywell vacuum relief paths is inoperable, thus ensuring that the design requirement of two 10 inch vacuum relief paths is met. The 30 day provision for restoration of the inoperable subsystem (s) is similar to provisions in Technical Specification 3/4.6.7.3 for one of the 100% redundant Combustible Gas Control Purge Systems inoperable. The 30 day restoration requirement is also intended to ensure that equipment is returned to service in a timely manner. The requirement that the inoperable subsystems be known to be closed is intended to ensure that a potential drywell bypass leakage path is not created with inoperable components.
: b. Action b Proposed Action b is similar to proposed Action a in that with two post-LOCA vacuum relief subsystems inoperable, only one 10 inch drywell vacuum relief path is inoperable. Therefore, present design assumptions of two 10 inch vacuum relief paths are still met with these two subsystems inoperable. A requirement to verify operability of the remaining two drywell purge vacuum relief subsystems provides further assurance that design requirements are being met while in this action statement. The justification for the 30 day restoration requirement is the same as for Action a above. The requirement that the inoperable subsystems be known to be closed is intended, as for Action a, to ensure that a potential drywell bypass leakage path is not created with inoperable components.
J10ATT86062401 - 4
: c. Action c Proposed Action c addresses the situation where inoperable drywell vacuum relief subsystems cause two of the three 10 inch drywell vacuum relief paths to be inoperable. This situation would occur if both drywell post-LOCA and one drywell purge vacuum relief subsystems are inoperable for opening but known to be closed. The proposed 72 hour limitation on continued plant operation is intended to allow adequate time for repairs while ensuring that systems needed to meet design requirements are returned to service as soon as possible. Plant shutdown is initiated if at least one of the inoperable subsystems is not restored to operable status within 72 hours. Restoration of at least one of these inoperable subsystems ensures that design requirements of two 10 inch vacuum relief paths are met. The requirement that the inoperable subsystems be known to be closed is intended, as for Actions a and b, to ensure that a potential drywell bypass leakage path is not created with inoperable components.
: d. Action d Proposed Action d is similar to present Action b for open vacuum breakers. Action d applies to only those vacuum breakers in the drywell post-LOCA (C61-F004 A&B) and drywell purge (C61-F002 A&B) vacuum relief subsystems that perform a drywell isolation function.
The 1 hour time for restoring the vacuum breakers to the closed position is the same as present provisions and is intended to help prevent a potential drywell bypass leakage path.
: e. Action e Proposed Action e is similar to present Action c with the addition of the position indication for the motor operated vacuum breaker isolation valves and plant shutdown requirements if associated valves cannot be verified to be closed. The NRC indicated in their safety evaluation dated July 23, 1985, that the installation of position switches with limited qualification on each of the six vacuum breaker check valves, the present qualified position indication on the isolation valves, and a common control room annunicator is an acceptable proposal. The proposed change will make the present tem Technical Specification 3/4.6.5)porary       (Note 1 of action requirements, J10ATT86062401 - 3 L-

permanent requirements for the position indication associated with the vacuum breaker isolation valves.
This proposed change will help to satisfy concerns about limited qualification of position indication on vacuum breaker check valves.
: 4. Surveillance Requirement 4.6.5 is changed to include the vacuum breaker check valves and motor operated isolation valves in the post-LOCA and purge vacuum relief subsystems.
Present Surveillance Requirements 4.6.7.3 on the purge system check valves and isolation valves have been repeated in Surveillance Requirement 4.6.5 to help ensure operability of these components for the drywell vacuum relief function.
: 5. Bases 3/4.6.5 is changed to reflect present design requirements for the drywell vacuum relief system.
SIGNIFICANT HAZARDS CONSIDERATION:
The changes to the subject technical specification are proposed to satisfy present licensing commitments, to locate all drywell vacuum relief requirements in one specification and to provide consistent action and surveillance requirements for all drywell vacuum relief subsystems. The safety related functions of the drywell vacuum relief subsystems are drywell isolation, proper operation of the drywell purge compressors, and operability in a large break LOCA to control weir wall overflow drag and impact loading to essential equipment and systems in the drywell above the weir wall. Technical Specifications 3/4.6.4 and 3/4.6.7 address operability requirements for drywell isolation and proper operation of the drywell purge compressors, respectively. Drywell negative presscre analysis forrapidweirwalloverflowinalargebreak(0CAassumesa vacuum breaker capability of A/      K = 0.38 ft requiring a minimum of two of the three installed 10 inch vacuum relief paths. The proposed action statement requirements are based on these design requirements and limit continued plant operation when they are not met. The present surveillance requirements are continued for the drywell post-LOCA vacuum breaker subsystems and are expanded to include the drywell purge subsystem components that perform a dryuell vacuum relief function.
The proposed changes do not involve a significant hazards consideration because operation of Grand Gulf Unit 1 in accordance with these changes would not:
: 1)   involve a significant increase in the probability or consequences of an accident previously evaluated.
The proposed changes add some requirements not J10ATT86062401 - 6

presently in the technical specifications that help to ensure consistent application of requirements for all drywell vacuum relief subsystems. Drywell vacuum relief is not required for hydrogen dilution or to reduce the pressure response in a Design Basis Accident. Drywell vacuum relief is required in a large break LOCA to control weir wall overflow drag and impact loading on certain essential equipment and systems. Two 10 inch drywell vacuum relief paths are required to meet design requirements. Proposed action changes reflect these operability requirements and limit the amount of time plant operation can continue when design requirements are not met. The addition of position indicators-in the action requirements for the motor operated isolation valves helps to further ensure closure of potential drywell bypass leakage paths during plant operation. Surveillance requirements are broadened by the proposed changes to include the drywell purge relief subsystems. Drywell isolation requirements and proper functioning of the drywell purge compressors are not impacted by the proposed changes since these requirements are covered in other unchanged specifications. Therefore, these changes cannot increase the probability or consequences of an accident.
: 2) create the pc:cibility of a new or different kind of accident from any previously analyzed. The proposed changes consolidate requirements for the drywell vacuum relief function into one technical specification. This consolidation will provide a consistent set of requirements for components associated with the drywell vacuum relief function and ensures that an orderly plant shutdown is required if design assumptions are not maintained. A consistent set of surveillance requirements is proposed for all components associated with the drywell' vacuum relief function. These tests will help to ensure operability of necessary equipment.
Drywell vacuum relief is needed by present design assumptions only to control weir wall overflow drag and impact loadin5 to essential equipment and systems in the drywell above the weir wall. No new or different kind of accident is postulated as a result of the proposed changes to the technical specifications.
: 3)  involve a significant reduction in a margin of safety. Proposed action and surveillance requirements are intended to ensure operability of required equipment necessary to meet design assumptions.
Plant operation is limited when components are inoperable that are necessary to ensure design assumptions are met. Therefore, the proposed changes will not reduce the margin of safety.
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