3F0198-16, Assists NRC in Completing Review of Issue Re Licensing Basis of HPI Protion of Mu Sys Per 971006-10 & 20-24 Insp. Descripion of Development of Licensing Basis of Issue Contained in Attachment

Assists NRC in Completing Review of Issue Re Licensing Basis of HPI Protion of Mu Sys Per 971006-10 & 20-24 Insp. Descripion of Development of Licensing Basis of Issue Contained in Attachment

ML20198H331
Person / Time
Site:	Crystal River
Issue date:	01/08/1998
From:	Grazio R FLORIDA POWER CORP.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
3F0198-16, 3F198-16, 50-302-97-14, NUDOCS 9801130255
Download: ML20198H331 (12)

Text

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= r January 8,_1998 3F0198-16.

.U. S'. Nuclear Regulatory Comission Attn: ' Document Control Desk Washington, DC 20555-0001

Subject:

Licensing Basis of the MU/HPI Comon Discharge Header

Reference:

FPC to NRC letter, 3F1197-36, dated November 10,1997, " Additional Information for SSFI Items, NRC Inspection No. 50-302/97-14"

Dear Sir:

During the recent US Nuclear Regulatory Commission (NRC) Safety System Functional Inspection (SSFI) conducted during the period October 6-10, 1997 and October 20-24, 1997, involving the review of the Makeup and Purification Systein (MU) and

. Decay Heat Removal Systems (DH), and other plant progr&ms, an issue arose that questionedthelicensingbasisoftheHighPressureInjectior.(HPI)portionof the MU System.-

lThe issue raised by the NRC Inspection Team involved the ability of Crystal River Unit 3 (CR-3) to isolate the MU/HPI common discharge header should a break occur along this header. The NRC questions centered around the fact that the discharge header is " common," and therefore,according to the team, CR-3 does not have the ability to isolate the system'should a break occur in this line. This lack of isolation:is 3rimarily the result of all four MU/HPI-discharge header valves 3eing requirec to be open and no ASME Section XI Inservice Testing (IST) Program

- stroke closure time-testing of two of the valves. The four valves include: MUV-3 and MUV-9 which are cotor-operated valves, and MUV-4 and MUV-8 which are manual gate' valves.

. Florida Power Corporation understands NRC Region II intends to request assistance from NRC Headquarters to determine if the valves in this discharge header are raquired for safe shutdown of the plant should a break occur in this line, and therefore should be included in~ the ASME Section XI Inservice Testing (IST)

Program. This letter is to assist the NRC in completing its review of the issue.

FPC is proviuing a description of the development of the licensing basis of this I issue in the' attachment to this letter. ]

' CRYSTAL RIVER ENERGY COMPLEX: 15700 W. Power une street e crystal her, Florida 34428-0700 e 1362) 795-6486 d S* m erm con,,nr 7 9901130255 990108

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U.- S. Nuclear Regulatory Commission

_.3F0198-16 Page 2 of 3 In summary, the current licensing basis for the common HPI discharge header is:

• All four valves (MVV-3, MUV-4, MUV-8,. and MUV-9) are required to be open because of the CR 3 Emergency Core Cooling System (ECCS) Small Break LOCA (SBLOCA) analysis which assumes _- flow in all four injection lines should only one HPI pump operate after an Engineered Safeguards (ES) actuation, and they are not required to change position to-accomplish their safety function.

• MUV-3 and MUV-9 are motorized 'to facilitate the isolation of leaks / breaks that may occur in the pump discharge piping leading to the HPI injectior nozzles.

• MUV-3 is also required to be locked open whenever makeup sump MUP-1B is running (which is normally the case) to preclude it from spuriously closing during an Appendix R event.

• MUV-9 is open with its power removed because of the Appendix R requirement for a dedicated train to support an Appendix R fire.

• MUV 3 and MUV-9 are identified for periodic stroke testing in the closed direction as part of the CR-3 IST Program as discussed in the reference letter. The IST Program also requires that they be stroked every two years to verify position indication.

• MUV-3 and MUV-9 are considered " passive" valves, i.e., they serse as part of the ASME Class 2 pressure boundary for the MU System because they are open in the LOCA analysis.

• There are no licensing restraints placed on MUV-4 and MUV-8, other than that they are only required to be in the open position.

As FPC shows _ in Attachment A, the MU/HPI common discharge header meets its current licensing basis as to ECCS SBLOCA analysis, single failure requirements, ,

IST -Program, Appendix R: Program requirements, High Energy Lins Break (HELB)

Program, Generic Letter 89-10 Program, and the Improved Technical Specifications.

Further, the-licensing submittals made to the NRC on this issue were found not to be in conflict with any other submittal made to the NRC and the current four crosstie' valve configuration with all the valves open saticfies these i requirements.

In-addition, since the header can be isolated from the Reactor Coolant System, its failure does_ not have to be considered for a design basis event. Therefore, none -of the four MU/Hel crosstie valves are relied upon to remain functional during and following a postulated design basis event.

A simplified: flow diagram of the MU System is also provided in Attachment B.

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U. S. Nuclear Regulatory Commission. ,

3F0198-16 Page:3 of 3 LThere are no new commitment's in this letter. ;I'f.you have any questions, please contact Mr. David F.- Kunsemiller, Manager, Nuclear Licensing, at (352)563-4566.

Sincerely, ,

09 (

R. E. GrazW -

Director-

' Nuclear Regulatory Affairs REG /jwt Attachment-

-xc: Regional Administrator, Region 11-Senior Resident Inspector NRR Project Manager-d d

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4-U. S. Huclear Regulatory Commission -Attachment A 3F1297-51 -

Page 1 of 8 HPI Discharge Header Licensing Basis The configuration of the HP! Discharge Header was addressed in-the original

' licensing of CR-3. The original-licensed condition of CR 3 required HPI-train

-separation (MVV-3 and MVV-4 closed). This configuration was later modified in 1979 to have a common discharge header as- part of the ECCS SBLOCA' analysis permanent fix solution to a " worst caw small break.

The following discussion describes the' correspondence chain that establShes the.

current licensing basis.

-a. On April 24, 1978, (FPC letter 3F0478-09), FPC submitted Licensee Event Report (LER) No. 78 019/0lT-0 informing the NRC of a B&W Report made available. to FPC of a 0.04 square foot pump discharge -break .being potentially a new " worst case" SBLOCA event for CR-3. This analysis came about as a result of a review of B&W's new 205 fuel assembly (205FA) plant design. The analysis showed that this break, which hypothetically could occur in the Reactor Coolant Pump (RCP) discharge piping, could result in uncovery of the reactor core for an extended period of time. The plant was subsequently shut down when this problem was identified.

b. On May 5,1978, (FPC letter 3F0578-04), FPC provided folicwup information -

to LER No. 78 019/0lT-0. FPC reported that an evaluation program was underway to fully explore the situation and define any necessary corrective actions for CR-3. A report of the evaluation results would be submitted to NRC on or before July 21, 1978.

c. On June 14, 1978, (FPC letter 3F0678-08), FPC submitted a report that justified startup and interim operation of CR-3 at full power prior to implementation of a permanent solution to the ECCS SBLOCA analysis problein. The justification for continued operation required four direct operator actions:

• "Upon ESFAS signal check for flow through both HPI trains."

• "If no flow in one train - open pump header cross-connect valves."

* " Secure flow through normal makeup line if flow is indicated."

• "Thrcttle HPI valves-as required to balance flow end meet run out limits."

These actions were evaluated against the then-current CR-3 Emergency Operating Procedures (E0P). followed by creation of a simulator training exercise that included this " worst case" small break, and evaluation of normal operator knowledge of the location and operation of the makeup pump cross-connect valves to ensure that'the " worst case" small break in the.

RCP discharge piping accident could be mitigated at CR-3.

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U. S. Nuclear Regulatory Commission Attachment A 3F1297-51 Page 2 of 8 HPI Discharge Header Licensing Basis

d. FPC informed NRC on July 21, 1978, (FPC letter 3F0778-05), July 27, 1978 (FPC letter 3F0778-07), and August 4, 1978, (FPC letter 3F0878-02) that its permanent solution to the ECCS SBLOCA analysis problem (i.e.,

concurrent SBLOCA with a loss of an Engineered Safeguards (ES) electrical bus which causes the inoperability of two HPI valves and one HPI pump) required the opening of all the HPI pump cross connect valves and switching power for the two inoperable HPI valves to the operable ES

• electrical bus. This manual pwer supply switching transfer would occur at the ES panel in the Main Control Room through an electro machanical transfer switch located at a new section on Engineered Safeguards (ES)

Motor Control Centers (MCC) ES-3Al MCC and ES-3B1-MCC, FPC estimated that these modifications would take 31 weeks to complete from the time of final NRC ~ approval .and installation of. the' modifications due to equipment procurement schedules.

In addition, FPC stated that the transfer of the two inoperable HPI v-1ves was required to be conipleted under operator action within 15 minutes from initiation of the SBLOCA event. Specifically, the operator must begin to open the HPI pump B-C discharge neader cross-over valves (MUV-3 and -4) and the HPI injection valves (HUV-23 and MUV-24 or MVV-25 and M'JV-26 depending on which Engineered Safeguard System (ESS) Subsystem lost power]

within five minutes of ectuatiori of the ESS and they must be fully open within~ an additional ten minutes This would assure that adequate timely flow to the core was provided,

e. On September 1, 1978 (NRC letter 3N0978-01), FPC was granted an exemption from the provisions of 10 CFR 50, paragraph 50.46(a) by NRC which allowed continued operation of CR-3 in tccorJance with the procedures described in FPC's June 14, 1978, letter. The oxemption was conditioned to terminate upon completion of the permanent salution to the SBLOCA analysis problem or completion c' the remainder of peerating Cycle 1, whichever occurred first.

f. NRC letter dated September 26, 1978, (NRC letter 3N0978-07), stated that FPC's " prompt" operator actions identified in its July 21, 1978 report were not considered " simple" operator actions. In turn, NRC provided examples of what they constituted " simp'e" operator actions. As a result, NRC requested that FPC proviie an alternative to the stated operator actions with an immediate response due within 7 days of receipt of their letter.

g. FPC informed NRC on October 9, 1978, (FPC letter 3F1078-02), that it intended to continue to pursue the modification it proposed in its July 21, 1978, response and that analyses were continuing to determine if operator action was required to balance the HPI flow under a one-pump, four-injection-line condition. The analysis was expected to be completed October 27, 1978. FPC also stated that its June 14, 1978, submittal did not meet any of NRC's criteria on " simple" operator actions for which credit may be taken following a Condition III event (small break).

U. S. Nuclear Regulatory Commission Attachment A 3F1297-51 Page 3 of 8 HPI Discharge Header Licensing Basis

h. On November 2, 1978, (NRC letter 3N1178-01), NRC requested that FPC provide schematic diagrams showing the controls and indications related to the motor-operated valve molded case breakers and the electro-mechanical transfer switches associated with the July 21, 1978, proposed modification. In addition, NRC requested that FPC verUy that it met sir.gle failure criteria by stating that it had physically separated the motor operated molded case breakers that were connected to the separate ES MCCs.

1. On November 17, 1978, (FPC letter 3F1178-07), FPC submitted the information requested by the November 2,1978, NRC letter and confirmed that the motor-operated valve molded case breakers that were to be onnected to the separate ES MCCs would be physically separated.

j. On January 12, 1979, (FPC letter 3F0179-04), FPC submitted its single failure analysis associated with the proposed ECCS modification for SBLOCA to the NRC, which stated the following assumptions:

• Small Break LOCA is the passive failure

• Concurrent loss of offsite power

• Must consider failure of each active component in the system NOTE: The active component failures considered in this document currently reside in FSAR Table 6-19. Failure of MUV-3 and MUV-9 are not discussed.

k. On March 14, 1979, (FPC letter 3F0379-04), in anticipation of not being able to install an NRC approved modification prior to restart from the Cycle 2 reload, FPC requested an exemption to Cycle 2 similar to that under which it was operating at the time.

1. On May 29, 1979, (NRC letter 3N0579-08), NRC approved FPC's responses regarding a permanent fix for the SBLOCA analysis issue.

m. On June 5,1979, (FPC letter 3F0679-01), FPC provided a response to an NRC Staff request for an economic impact assessment of requiring the modification be installed prior to restart from the current outage.

Basically, FPC stated in order to avoid costing consumers upwards of $15.3 million in replacement fuel costs, FPC requested that the exemption from 10 CFR 50.46 be granted and that the facility be authorized to operate at rated thermal power until August 6,1979. In addition, FPC stated that the justification for restart and operation contained in its June 14, 1978, letter remained valid,

n. On July 3, 1979, (NRC letter 3N0779-01), granted the requested FPC exemption until August 6, 1979.

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' U. S. Nuclear Regulatory Commission Attachment A 3F1297-51_ Page 4 of 8 HPI Discharge Header Licensing Basis

o. On September 14, 1979, NRC Inspection Report 50-302/79-30, (NRC letter 3N0979-23), verified that on August 6, 1979 that MAR M-79-05-63, which involved leaving the HPI pump manual cross connect valves open and providing a means of supplying electrical power to the motor operators of the HPI injection valves from the Engineered Safeguards (ES) electrical t busses of both channels, had been completed. The valves were also

~

verified adequately time-stroke tested with each power supply in accordance with SP-355, " Operations ES Monthly Functional Tests," and SP-370, " Quarterly Cycling of Valves," on August 5,1979,

p. In 1980, FPC completed MAR 79-08 06 which installed motor operators on MU/HPI crosstie valves MUV-3 and MUV-9 to facilitate the isolation of leaks / breaks a may occur in the pump dist.harge piping leading to the HPI injection nozzles.

o. On October 23, 1981, NRC Region 11 noted that MUV-3 and MUV-9 had motor operators added to them to enable remote isolation as documented in NRC Inspection Report 50-302/81-19 (NRC letter 3'W 1-12) .

In summary, MUV-3, MUV-4, MVV-8 and MUV-9 must remain open in order to meet the HPI system configuration to support mitigation of a SBLOCA.

Other Related Information Used In=Definino the Current Licensina Basis:

a. MU/HPI Pump Testing Requirements Associated with the Crosstie Valves In accordance with ASME Section XI, Subsections IWV and IWP,1983 Edition, Summer,1983 Addenda, FPC is required to perform a functional test of its MU pumps (MVP-1A, MVP-1B, MVP-lC) and associated safety-related valves to provide assurance that they are operable. These tests are performed in accordance with Surveillance Procedures SP-3400, "MVP-1A, MVP-18, and Valve Surveillance," and SP-340F, "MVP-10 and Valve Surveillance."

In order to perform this test, HPI train separation is required. For example, to test the MVP-1A pump, either MUV-8 or MUV-9 must be closed.

Both valve closures are not necessary. This places the plant in the 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> action statement of ITS 3.5.2.

b. Single Failure Criteria Associated with Using the Crosstie Valves for MU/HPI Header Isolation Should a - break occur anywhere along the MU/HPI header, any one of a combination of:HUV-3, MUV-4, MUV-8, and/or MUV-9 can be shut to isolate the leak / break. If a valve fails to close due to boron crystal buildup or other potential failure mechanism, one of the other three valves can be ~

closed. FPC considers it incredible that all four valves will fail to close considering single failure criteria as described earlier in this letter.

U. S. Nuclear. Regulatory Commission Attachment A MPI Discharge Header Licensing Basis

c. IST Program Considerations for MVV-3, MUV-4, MUV-8, and MUV-9 In 1980, manually operated gate valves MUV-3 and MVV-9 were motorized (MAR 79 08-06) to facilitate the isolation of leaks / breaks in the MU/HPI common discharge header. Once the actuators to these valves were converted to MOVs, they were immediately considered " active" valves, even though they were always maintained open to meet the CR-3 SBLOLA analysis. Therefore, the valves were placed in the ASME Section XI IST Program and time-stroke tested on a quarterly basis. This philosophy of testing the valves as

" active" components continued until 1991 when - the valves were re-classified as " passive" valves and time-stroke testing was eliminated. On November 10,1997, (FPC letter 3F1197-36), FPC informed the NRC that these valves would be time-stroke tested to the closed position on a quarterly basis beginning in 1998.

MUV-3 and MUV-9 are considered safety-related, ;,5ME Class 2 valves in the FPC Configuration Management Information system (CMIS) and currently are stroke tested on a biennial basis to verify position indication as part of

-the CR-3 IST-Program. This action is in accordance with Subsection IWV-3300 of the ASME Code which states that valves with remote position indicators shall be observed at least once every two (2) years-to verify that valve operation is accurately identified.

MVV-4 and MUV-8 are not addressed by the program because of their manual handwheel actuator status,

d. Generic Letter (GL) 89-10 Motor-0perated Valve (MOV) Testing Program On March 8,1994, (FPC letter 3F0394-03), FPC submitted its GL 89-10 Program Status involving MOV activities which included a list of valves that could not be dynamically tested. Consistent with CR-3's MOV Program-and recommendations of GL 89-10, those valves that_ could not be dynamically tested were setup using the best information then available.

MVV-3 and MVV-9 were considered two of the valves that could not be dynamically tested, which would then man only a functional- verification would be ccnducted. This submittal, and FPC's final submittal dated June 22,1994 (FPC letter 3F0694-15) were ~ reviewed and approved by NRC on

-November-13, 1995 (NRC Letter 3N1195-09).

Subsequent to this NRC approval, NRC issued Supplement 7 to GL 89-10 on January 24' 1996 (NRC letter 3N0196-12). In this supplement, NRC removed its recommendation that MOV mispositioning be considered by PWR licensees in responding to GL 89-10. As a result of this relaxation,'FPC removed MUV-3'and MUV-9 from the CR-3 MOV Testing Program.

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U. S. Nuclear Regulatory Commission Attar.hment A 3F1297-51 Page 6 of 8 HPI Discharge Header Licensing Basis

e. Use of Non-Safety Related Operators and Power Supplies Associated with MUV-3 and MVV-9 In accordance with the 10 CFR 50.2 definition of " safety-related structures, s/ stems, and components," FPC concluded that the MUV-3 and MVV-9 valve operators are not relied on to function during and following a postulated design basis event. Therefore, the valves have non-safety-related motor operators and are connected to a non-ES electrical buses.

f. High Energy Line Break (HELB) Outside the Reactor Building Program The High Energy Line Break Outside the Reactor Building Program included the MU System. The HELB Program was part of e 'chedular exemption request from the requircments of 10 CFR 50, Appendix A, General Cesign Criteria (GDC) 4, that was provided to the NRC on May 24,1989, (FPC letter 3F0589-20). This program was approved by NRC under its Schedular Exemption Approval from the requirements of GDC-4, based, in part, on the following FPC statements made about the MU/HPI common discharge header:

The redundancy built into the Make-Up System is sufficient to overcome any challenge to system function presented by a High Energy Line Break.

- Two (2) independent supply lines ensure borated water is supplied to the Make-Up Pump (HUP) suction header.

- A common suction header supplies three (3), 200% capscity MUPs. A disabled portion of this hcader can be isolated either mmately or manually, ensuring two (2) of three (3) MUPs are supplied with water.

- The three (3), 200% capacity MUPs discharge to a common header, allowing any single pump to supply multiple injection lines. This common discharge header contains bot. manual and remotely operated valves which can isolate any disabled section, ensuring three (3) of five (5) potential flow paths are available to supply the Reactor Coolant System (RCS) with borated water.

- There are five (5) potential flow paths for borated water into the RCS, four (4) High Pressure Injection (HPI) lines, and one (1) Reactor Coolant Pump seal injection line. Each of these five (5) lines is independent and can be placed in service or isolated from the control room.

Keeping the redundancy built into the Make-Up System in mind, each potential break location has been reviewed to discount any credible threat to system function.

U. S. Nuclear Regulatory Commission Attachment A 3F1297-51 Page 7 of 8 HPI Discharge Header Licensing Basis On April 11, 1990 (NRC letter 3N0490-10), the NRC approved of the CR-3 HELB Program which remains a part of the CR-3 licensing basis,

g. Lock Open of the MUV-9 Electrical Power Supply Breakers

• On October 29,1982 (FPC letter 3F1082-32), FPC submitted its 10 CFR 50 Appendix R Fire Study as part of its response to the NRC Generic Letter 81 12 on Fire Protection. In this response, FPC also included information related to a Request for Additional Information Teleconference it held with the NRC on October 19, 1982. The followin9 was FPC's response to NRC Question #7, involving Makeup and Purification system components:

Item 7: Provide a list of "A" and "B" Dedicated Shutdown equipmcat.

Response: The following listing provides a breakdown of equipment into redundant channels of "A" and "B" engineered safeguards power. The list is presented on a system basis and includes the components required to achieve cold shutdown in the event of a fire occurring in any fire area of the plant....

"A" "B" "AB" "Non-Class IE" MVP-1A MVP-lc MVP-1B* MVV-3**

MUV-73 MUV-58 MUV-25 MUV-9***

MVP-2A MVP-2C MVV-26 MVV-62**

MVP-4A MVP-4C MUV-27 MUV-69**

MVP-2B MVP-4B

• MVP-1B is the swing pump capable of being powered from either the ES "A" or ES "B" 4 kV switchgear.

• • Spurious operation of MUV-3 and MUV-62 will not affect shutdown operation unless MVP-1B is being used in place of MVP-lC, Whenever this particular pump alignment is used, MVV-3 and MUV-62 will be locked open at the MCC to preclude any detrimental effects. Likewise, spurious operation of MUV-69 will not affect shutdown operation unless MVP-1B is being used in place of MVP-1A.

-4 U.- S. ' Nuclear Regulatory' Commission - Attachment A-Page 8 of 8-3F1297-51 .

_HPI Discharge Header Licensing Basis Whenever this particular pump alignment is used, MUV-69 will' be locked open to. preclude any detrimentk1 effects.

'** MUV-9 will be locked open at the MCC and will remain open throughout plant shutdown operation.

• On1 January 6,1983 (hRC letter 3N0183-05), NRC approved FPC's Safe Shutdown capability of CR 3 in the event of a fire at the plant.- As part of NRC's attached Safety Evaluation Report, the NRC endorsed

-FPC's proposed modifications to CR-3 identified in its October 29, lob 2 response. The power supplies to MVV-9, MUV-62, and MUV-69 were subsequently removed and their electrical breakers locked open.at their respective motor control centers in accordance with MAR 82 1.1-07 and Work Request 49941. MUV-9 is located on Elevation 95 of the Auxiliary Building (AB). The breaker for MVV-9 is located in MCC-3B1, which _1s on Elevation 143 of the AB, so the breaker is accessible to restore . power -in the unlikely event of a _ piping rupture in the vi:inity of MVV-9. -

h. On November 10, 1997, (FPC Letter 3F1197-36)', FPC committeo to add MUV-3 and MVV-9 to the ASME Section XI IST Program for quarterly stroke time-testing in the closed direction by March 31, 1998.

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