ML20204A368

Forwards Comments Re Applicability of Type C Local Leak Testing for Certain Containment Isolation Valves & Response to Inquiries Concerning Nonessential Status of Certain Sys Penetrating Containment.Three Oversize FSAR Revs Also Encl

ML20204A368
Person / Time
Site:	Seabrook
Issue date:	05/07/1986
From:	Devincentis J PUBLIC SERVICE CO. OF NEW HAMPSHIRE
To:	Noonan V Office of Nuclear Reactor Regulation
References
SBN-1034, NUDOCS 8605120129
Download: ML20204A368 (14)

Text

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SEABROOK STATION l Engin:sring Office SBN- 1034 Pubuc Service of New Hampshire T.F. B3.0.0, P2.6.3, B7.1.3 United States Nuclear Regulatory Commission Washington, DC 20555 Attention: Mr. Vincent S. Noonan, Project Director PWR Project Directorate No. 5

Reference:

(a) Construction Permits CPPR-135 and CPPR-136, Docket Nos. 50-443 and 50-444 Subject : Containment Isolation System /10CFR50 Appendix J, Type C Leak Rate Testing

Dear Sir:

Enclosed as Attachment 1 is our position regarding the applicability of Type C Local Leak Testing for certain containment isolation valves. Also enclosed as Attachment 2 is our response to recent NRC inquiries pertaining to the "Non-Essential" status of certain systems penetrating containment.

The applicable FSAR revisions are provided herewith as Attachment 3. These FSAR revisions will be incorporated into the FS AR via a future amendment.

We request that you review the enclosed and reflect its acceptability in the next supplement to Seabrook's SER.

Very truly yours,

/k U ohn DeVincentis, Director Engineering and Licensing Enclosures cc: Atomic Safety and Licensing Board Service List 507 86051%1298OCg oO 443 pg PDR

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Seabrook Station Construction Field Office P.O. Box 700 Seabrook, NH O3874

i Diane curran, Esquire Calvi:3 A. Canneg' j Marison & Weiss City Manager 2001 S. Street, N.W. City Hall - l

, Suite 430 126 Daniel Street l Washington, D.C. 20009 -

Portsmouth. Inf 0380,1 Sherwin E. Turk, Esq. Stephen E. Morrill, Esquire ,

Office of the Executive Legal Director Attorney General [

U.S. Nuclear Regulatory Commission Coorge Dana Bisbee, Esquire -

Tenth Floor Assistant Attontey General Washington, DC 20555 offlee of the Attorney General  !

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Philip Ahrens, Esquire Rye, NH 03870 Assistant Attorney General Department of The Attorney General Mr. Angle Machiros Statehouse Station M Chairman of the Board of Selectmen hugusta. ME 04333 Town of Newbury

l Newbury, MA 01950 Mrs. Sandra Cavutis chairman, Board of Selectmen Mr. William 8. Lord RFD 1 - Sox 1154 Board of Selectmen l Kennsington, NN 03427 Town Mall - Friend Street Amesbury, MA 01913 Carol S. Sneider, Esquire Assistant Attorney General Senator Gordon J. Humphrey Department of the Attorney General 1 Pillsbury Street One Ashburton Place, 19th Floor Concord, EN 03301 Boston, MA 02108 (ATTN: Norb Boynton)

Senator Gordon J. Humphrey N. Joseph Flynn Esquire l

U.S. Senate Office of General Counsel ,

Washington, DC 20510 Federal meergency Management Agencyg

(ATTN: Tom Burack) 500 C Street, SW ' ,

l # Washington, DC 20472 i Richard A. Hampe, Esq.

i Hampe and McNicholas Paul McEachern, Esquire I

35 Pleasant Street Matthew T. Brock Esquire Concord, NH 03301 Shaines & McEachern 25 Maplewood Avenue Donald E. Chick P.O. Box 360 Town Manager Portsmouth, NH 03801 Town of Exeter 10 Front Street Cary W. Holmes, Esq.

Exeter, NN 03833 Holmes & Ells 47 Winnacunnet Road Brentwood Board of Selectmen Hampton, NH 03041 RFD Dalton Road Brentwood, NH 03833 Mr. Ed Thomas FEMA Jtegion I Peter J. Mathews, Mayor 442 John W. McCormack PO & Courthouse City Hall Boston, MA 02109 Newburyport, MA 01950 Stanley W. Knowles, Chairman Board of Selectmen P.O. Box 710

• North Hampton, NH 03862

i SBN-1034 ATTACHMENT 1 Type C Local Leak Testing Contai nment penet rations X-1, X-2, X-3, X-4, X-5, X-6, X-7, X-8, X-48A, X-48B, X-49A, X-49B, X-63, X-64, X-65, and X-66 serve the Main Steam, Feedwater, Primary Component Cooling Water, and Steam Generator Blowdown Systems. The lines associated with these penetrations form closed systems inside containment per 10CFR50, General Design Criteria 57, which satisfy the following design criteria.

o The systems do not communicate with either the reactor coolant system or the containment atmosphere.

o The systems are Safety Class 2.

o The systems are Seismic Category I.

o The systems are protected against missiles.

o The systems are protected against the dynamic effects asso-ciated with pipe ruptures.

o The systems are designed to withstand temperatures at least equal to the containment design temperature.

o The systems are designed to withstand the external pressure from the containment structural integrity test.

o The systems are designed to withstaad the environment and transient conditions resulting from either a loss of coolant accident or a main steam line break.

In the event of a LOCA, the isolation valves associated with these penetrations will not communicate with containment atmosphere, and hence, will not realize post-accident containment pressure. These isolation valves are, therefore, not subj ect to Type 'C' testing. The integrity of the closed systems discussed above will be tested during preoperational and periodic Type ' A' testing (ILRT).

Containment penetrations X-71A/74A, X-71B/74B, X-72A/75A, and X-72B/

75B are the supply and return lines for the two hydrogen gas analyzers (CGC-CP-173 and CGC-CP-174). These lines form two closed systems (Train ' A' and Train 'B') outside containment which satisfy the following design cri-teria.

o The systems are Seismic Category I.

o The systems are Safety Class 2 up to the analyzer isolation valves downstream of the containment isolation valves.

O SBN- 1034 ATTACRMENT 1 Type C Local Leak Testing (Continued)

Any leakage through the containment isolation valves associated with these penetrations will be contained by these closed systems.

The isolation valves are, therefore, not subject to Type 'C' testing.

The integrity of the closed systems outside containment is tested by opening the isolation valves during preoperational and periodic Type

'A' testing, thereby subjecting each system boundary to postulated post-accident containment pressure.

Several containment penetrations associated with the Emergency Core Cooling Systems (ECCS) will realize a water seal maintained at a pressure greater than 1.10 Pa following a LOCA. The ECCS satisfies the following design criteria.

o The system is Safety Class 2.

o The system is Seismic Category I.

o The system is protected against missiles.

o The system is protected against the dynamic ef fects associated with pipe ruptures.

o Active electrical components are classified as IE and receive emergency power from the diesel generators. Failure of a diesel generator results in the loss of one train of active ECCS components. The redundant diesel will continue to power the fully redundant ECCS Train.

The penetrations at which this pressurized water seal will be maintained throughout the entire 30 day accident mitigation are X-24, X-25, X-26, X-27, X-28, X-29, X-30, X-31, and X-3 3. Details of hy-draulic conditions at the penetrations and related system operation will be described in subsequent paragraphs. The total minimum water inventory for the ECCS is approximately 224,000 gallons. This inven-tory includes only recoverable quantities of water from the refueling water storage tank (RWST), the spray additive tank (SAT) and 3 of 4 accumulators. It does not include any potentially recoverable reactor coolant or the quantity of water which may accumulate in cubicles / areas located such that the water is not available to the containment sumps for recirculation. Section 15.6.5.4.d of the FSAR provides an esti-mated leak rate from the ECCS outside containment of 24 gallons per day.

The remaining water inventory of 223,280 will assure the water-filled status of the ECCS for 30 days after the onset of an accident.

SBN 1034 ATTACRMENT 1 Type C Local Leak Testing (Continued)

Penetration X-27 is the discharge line to all four RCS cold legs f, rom the safety injection pumps. The isolation valve outside containment

'or. this penetration (SI-V114) will be open during cold leg injection and cold leg recirculation and closed during hot leg recirculation. This line is a continuation of .the crosstie line between both pumps' discharge lines. Given the above discussion on penetrations X-25 and X-26, it follows that a pressurized water seal will be maintained at penetration X-27 for 30 days following the onset of an accident regardless of single active failure.

-Penetrations X-28, X-29, X-30, and X-31 are the centrifugal charging pumps' discharge lines to the reactor coolant pumps' seals. The isolation valves outside containment for these penetrations (CS-V154, CS-V158, CS-V162, and CS-V166) do not close automatically following an accident and may remain open during accident mitigation. These lines are supplied water from the discharge header common to both charging pumps. Therefore, a water seal at a pressure greater than 1.10 Pa will be maintained at these penetrations for 30 days following the onset of an accident regardless of single active failure.

Penetration X-33 is the normal charging line from the centrifugal

- charging pumps' common discharge header. The isolation valve outside containment for this penetration (CS-V143) will be closed throughout the entire accident mitigation process. Because the line is pressurized by the discharge header common to both charging pumps, the penetration will realize a water seal at a pressure greater than 1.10 Pa for 30 days following an accident regardless of single active failure.

As previously discussed, a water seal at a pressure greater than

- 1.10 aP will be maintained at penetrations X-24, X-25, X-26, X-27, X-28, X-29, X-30, X-31, and X-33 for 30 days following the onset of an accident.

This seal precludes any isolation valve seat leakage of containment at-mosphere. In addition, all containment isolation valves for these pene-trations located outside containment which may be closed at some time following an accident are wedge-type gate valves. Their design allows for stem / packing leakage only from the high pressure side of the wedge.

Given that a water seal will be maintained on the side of the wedge

- gate away from containment at a pressure greater than 1.10 Pa , contain-ment atmosphere leakage from the stems or packing on these valves is precluded. Therefore, all of the containment isolation valves asso-ciated with the penetrations listed above are not subject to Type 'C' testing.

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SBN- 1036 ATTACRMENT 1 Type C Local Leak Testing (Continued)

Containment penetrations X-60 and X-61 are the suction lines for the containment spray and RilR pumps from the containment sumps. Each of these penetrations has one isolation valve located outside contain-ment (CBS-V8 and CBS-V14) which will be closed during cold leg injec-tion and open during cold and hot leg recirculation. The containment recirculation sumps and these associated penetrations will fill with water almost immediately following the onset of an accident. Because the petetrations will be filled with water for essentially 30 days folloising the onset of an accident and the isolation valves are in-tended to be open during most of the accident mitigation process, the

-sives are not subject to Type 'C' testing.

SBN- 1034 ATTACHMENT 2 Additional Information; Non-Essential Status Table 6.2-83 of the FS AR indicates that the systems associated with containment penetrations X-28, X-29, X-30, X-31, X-48A, X-48B, X-49A, and X-498 are not essential for mitigating the consequences of an accident but the penetrations are not isolated-in the event of such an accident. These penetrations serve the reactor coolant pump seal injection lines and the component cooling water supply and return lines for the thermal barrier heat exchangers respectively. While these systems are not essential for mitigating the consequences of an accident, it is beneficial under all conditions to maintain a cooled water supply to the RCP seals. In addition, leakage of containmant atmosphere through these penetrations is precluded for reasons out-

' lined in Attachment 1.

Table 6.2-83 also indicates that the systems associated with con-tainment penetrations X-77A, X-77B, X-78A, and X-78B are not essential for mitigating the consequences of an accident. These penetrations serve the reactor vessel level indication system which provides infor-3 mation necessary for accident mitigation. The FSAR will be reviewed to indicate that the systems are essential.

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r SBN- 1034 ATTACHMENT 3 FSAR Revisions (FSAR Section 6.2)

SB 1 & 2 Amendmsnt 58 FSAR April 1986 6.2.6.3 Containment Isolation valve Leakage Rate Test -

Tyoe C Test Type C tests are required on all lines that penetrate the primary containment cnd present a potential leakage path between the inside and outside atmospheres of the primary containment under postulated accident conditions. These include lines: 1) that provide a direct connection between containment atmosphere cnd the outside, like purge and vent lines; 2) whose isolation valves are required to close automatically upon receipt of a containment isolation signal for the purpose of isolating containment atmosphere or the reactor coolant system; or, 3) whose isolation valves are required to operate intermittently under post-accident conditions for the purpose of isolating containment atmosphere or the reactor coolant system. Table 6.2-83 lists all lines penetrating the containment and, where applicable, the containment isolation valves associated with those lines. Those lines not considered as requiring testing are noted. Containment isolation valves which are not Type C tested, and the reasons thereof, can be categorized as follows:

a. Valves that isolate lines which form a closed system inside containment satisfying the criteria of FSAR Subsection 6.2 4.1.c are not Type C tested. These systems, and therefore their respective containment isolation valves, will not communi; ate with containment atmosphere or the reactor coolant system und..r post-accident conditions. These systems include main steam, feedwater, and steam generator blowdown j 11*' r;h it: 1._1 ... r:1::: iii

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b. Certain ECCS containment isolation valves are not Type C tested.

The primary function of many of these valves is not to isolate containment following an accident, but rather to direct emergency core cooling water as desired. In fact, most of the valves will be open during one or more of the three ECCS post-accident modes.

In addition, the valves are part of Safety Class 2/ seismic Category I systems that are closed outside containment and liquid-filled, with an assured post-accident 30 day water supply.

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c. The containment isolation valves on the CGC hydrogen analyzer lines are not Type C tested. These lines form a closed, seismic Category I system outside containment. The integrity or the closed system will be tested by leaving the containment isolation valves open during the Type A test.

6.2-85

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s INSERT "A" (Insert onto FSAR page 6.2-85)

A water. seal at a pressure greater than 1.10 Pa will be

{ maintained at the containment penetrations associated with j these isolation valves for the 30 day post-accident period.

This seal precludes leakage of containment atmosphere.

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SBN- 1034 ATTACHKENT 1 Type C Local Leak Testing (Continued)

The post-accident operation of the ECCS can be described in 3 phases. Immediately following the accident, the RHR pumps (RH-P-8A and RH-P-8B), the centrifugal charging pumps (CS-P-2A and CS-P-2B),

and the safety injection pumps (SI-P-6A and SI-P-6B) are all aligned to take suction from the RWST and discharge to all 4 RCS cold legs (cold leg injection). In the presence of a 'P' signal (Phase 'B' isolation) the containment spray pumps (CBS-P-9A and CBS-P-9B) also take suction from the RWST and discharge to the spray ring headers.

When the RWST reaches the " low-low" level, the containment sumps' isolation valves are manually opened and the system enters the cold leg recirculation mode. During this phase, the RHR pumps and contain-ment spray pumps take suction from the containment sumps. The RHR pumps continue discharging to the RCS cold legs, and also deliver water to a suction header common to the safety injection and charging pumps. These pumps also continue discharging to the RCS cold legs.

Approximately 18 hours2.083333e-4 days <br />0.005 hours <br />2.97619e-5 weeks <br />6.849e-6 months <br /> after the onset of an accident, the system is switched over to the hot leg recirculation mode. During this phase, the RHR and containment pumps continue taking suction from the con-tainment sumps. The RHR pumps are aligned to discharge to RCS hot legs 1 and 4, as well as the SI/CS pumps' common suction header. The safety injection pumps are aligned to discharge to all 4 RCS hot legs, and the charging pumps continue discharging to all 4 RCS cold legs.

Reference Section 6.3 of the FSAR for a more detailed description of ECCS operation.

Penetration X-24 is the common discharge line from the centrifugal charging pumps to all four RCS cold legs. The isolation valves outside containment for the penetration (SI-V138 and SI-V139) will be open for the entire accident mitigation process. Both charging pumps discharge to a common header throughout accident mitigation. Therefore, a water seal at a pressure greater than 1.10 Pa will be maintained at the pene-tration for 30 days following the onset of an accident regardless of single active failure.

Penetrations X-25 and X-26 are the discharge lines from the safety injection pumps to all four RCS hot legs. The isolation valves outside containment for these penetrations (SI-V77 and SI-V102) will be closed for cold leg injection and cold leg recirculation and open during hot leg recirculation. During cold leg injection and recirculation, the crosstie line between both pumps' discharge lines will not be isolated.

Therefore, regardless of single active failure a water seal at a pressure greater than 1.10 Pa will still be maintained at these penetrations by the redundant SI pump. During hot leg recirculation, the crosstie isolation valves (SI-Vill and SI-V112) are closed. However, during both recirc-ulation phases the RHR pump (s) deliver water to a suction header common to both SI pumps. During preoperational testing with one RHR pump delivering to this suction header, the suction pressure for both SI pumps was in excess of 1.10 Pa. Therefore, should a single active failure occur, a water seal pressurized to 1.10 P a will still be main-tained at the penetration corresponding to the failed SI pump by the lone operating RHR pump. It follows that a pressurized water seal will be maintained at these penetrations for 30 days following the onset of an accident regardless of single active failure.

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