B12968, Forwards Listing of Containment Isolation Valves to Clarify Isolation Boundaries & Address Concerns Noted in Insp Repts 50-245/87-09 & 50-245/88-02.Alternative Bases for Deviations Include Closed Loop Sys & Extension of Containment

Forwards Listing of Containment Isolation Valves to Clarify Isolation Boundaries & Address Concerns Noted in Insp Repts 50-245/87-09 & 50-245/88-02.Alternative Bases for Deviations Include Closed Loop Sys & Extension of Containment

ML20151N566
Person / Time
Site:	Millstone
Issue date:	07/29/1988
From:	Mroczka E NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
B12968, NUDOCS 8808090036
Download: ML20151N566 (12)

Text

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MEAST UTILITIES cene,ai ori:ces . seieen aireet. seriin. Connect cut H ART FORD. CONN ECTICUT 06141-o27o L t T; 'Cr,:Cll."'20'!, (203) ses-sooo July 29, 1988 Docket No. 50-245 B12968 Re: 10CFR50, Appendix J 10CFR50, Appendix A U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555 Gentlemen:

Millstone Nuclear Power Station, Unit No. 1 Containment Isolation Boundaries In order to further address ongoing issues pertaining to containment isolation boundary requirements, Northeast Nuclear Energy Company (NNECO) is providing a complete listing of all containment isolation valves (CIVs) at Millstone Unit No. I and our bases for CIV designations differing from 10CFR50, Appendix A, General Design Criteria (GDC) 54 through 57. This information, provided as Attachments 1 and 2 to this letter, serves to clarify which valves are consid-ered containment isolation boundaries at Hillstone Unit No. I and is provided to further address concerns discussed in Inspection Report Nos. 50-245/87-09 and 50-245/88-02, References (1) and (2). The 9" Staff expressed concern with portions of Millstone Unit No. l's local leak rate test program and compliance with ASME Boiler and Pressure Vessel Code Section XI.

Backaround On February 14, 1973 Appendix J to 10CFR50 was published which modified the requirements of the containment testing program. By letter dated August 7, 1975, Reference (3), the NRC requested NNEC0 to review its containment testing program for Millstone Unit No. I and the related technical specifications, for compliance with the requirements of Appendix J to 10CFR50. References (4) through (13) document correspondence between NNECO and the NRC regarding I requests for exemption from certzin requirements of Appendix J. Br letter dated May 10, 1985, Reference (14), the NRC found NNEC0's requests fo. exemp-tion acceptable. However, it should be noted that leveral areas pertaining to containment isolation boundary requiremests remained unresolved. Additional Appendix J exemption requests were submitted to the NRC Staff on April 29, 1988, Reference (15), and are pen:ing NRC review.

Discussion Containment isolation boundary requirements are stated in 10CFR50, Appendix A GOC 54 through 57. Many of the containment boundary configurations at Hillstone Unit No. I are consistent with the GDC. NNEC0 believes that 8808090036 880729 PDR ADOCK 05000245 i\

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U.S. Nuclear Regulatory Comission B12968/Page 2 <

July 29, 1988 configurations that differ from the GDC are technically justified on other bases as discussed in Attachment 2. NNECO and the NRC have explored these other bases in the Systematic Evaluation Program (SEP), Topic VI-4, and as documented in References (4) - (18).

In summary, many of the alternative bases for deviations fall into three major categories as foilows:

o Closed Looo Systems These systems are high integrity piping loops that run through containment without communicating with containment atmosphere or reactor coolant, or run outside containment as closed extensions of the drywell and torus. These systems are o9nerally safety related or Emergency Safeguard Features (ESF). Therefore, they are generally main-tained as safety class, quality assurance Category I (QA Cat. I) items.

Many of these systems are seismically designed. They are designed and installed in accordance with an augmented version of the B31.1 Power Piping Code, and are located in missile protected areas. These loops are designed to withstand the internal and external affects of a Loss of Coolant Accident (LOCA) or post-LOCA isolation. While these characteris-tics are not identical to the closed hop criteria identified in ANSI N271-76 (ANS 56.2) or NUREG-0800 Sectien 6.2.4, they are adequately comparable to these standards. These criteria were issued after Millstone Unit LO. I received its operating license and are not part of its licensing basis. In addition, most of these systems demonstrate their leak tightness functionally on a continuous basis during normal plant operations or periodically during inservice testing. In summary, these systems have been designed, installed, and maintained to meet or exceed the closed loop criteria in effect during the design of the M111 stone Unit No. I plant.

o Extensions of Containment - Some instrument lines off of containment, or system branches like the scram discharge volumes, are designed to act as extensions of containment. These lines are generally designed to crite-da shailar to those listed for closed loops above. Instrument lines are generally small enough to restrict leakage to the extent that failure of a single line is not a very probable cause for exceeding off-site dose cocequence limits. For these reasons, it is concluded that the affected systems have been designed to remain open to containment, as extensions of containment, during a LOCA.

o Two CIVs Outside Containment - Many of the new or recently modified systems at Millstone Unit No.1 employ two CIVs outside containment at each penetration. Appendix A GDCs state that one CIV should be located inside containment and another located outside containment in systems that are not closed loops. The alternative configurations utilized at Hillstone Unit No. 1 are justified by the lack of space and inaccessibil-ity of many penetrations within containment, reduced installation cost, and reduced personnel expccure for installation, maintenance, and 10CFR50, Appendix J Type C testing. The acceptability of locating two valves outside containment was addressed in NUREG-0824 Section 4.20.4.

This subsection of SEP Topic VI-4 concluded that there is little differ-ence, from a probabilistic risk standpoint, in locating two CIVs outside containment or configuring valves as specified in the GDC.

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U.S. Nuclear Reguistory Commission B12968/Page 3 July 29,1988 It is important to note that in some cases, CIV configurations that comply with Appendix A have been modified to permit closer compliance to Appendix J. For example, most of the ESF systems and the shutdown cooling system have CIVs inside and outside of the primary containment boundary. These configurations comply with Appendix A GDC. However, testing of all of these valves in accordance with Appendix J is not feasible (e.g., due to lack of test connections, inability to satisfy reverse direction testing criteria, etc.). To resolve this dilemma, NNECO designated containment boundaries that took advantage of the closed loop feature in these systems. This approach has been identified to the NRC as documented in References (4) - (18).

These alternative bases, and any others that are applicable to a penetration's CIV configuration, are listed in Attachment 2.

Summary It is NNEC0's intention that this information serve to consolidate past efforts regarding containment isolation boundary requirements and containment testing programs at Millstone Unit No. 1.

NNECO nas taken action to incorporate the CIV listing of Attachment 1 into the Millsaone Unit No. 1 Updated Final Safety Analysis Report. We have also completed a preliminary review of Millstone Unit No. I's Technical Specifica-tions to ensure consistency with Attachment 1. It is anticipated that valves LP-43A and 438 will be added to Technical Specification Table 3.7-1, pending further review.

Please feel free to contar.t us if you have any questions regarding this matter.

Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY Y Mx E. .ftoczka?/

Senior Vice President cc: W. T. Russell, Region I Administrator M. L. Boyle, NRC Project Manager, Millstone Unit No. 1 W. J. Raymond, Senior Resident Inspector, Millstone Unit Nos.1, 2 and 3

. U.S. Nuclear Regulatory Commission B12968/Page 4 July 29, 1988

References:

(1) D. M. Crutchfield letter to E. J. Mroczka, "NRC Inspection Report No. 50-245/87-09 (4/20/87 -

4/24/87)," dated July 1, 1987.

(2) NRC Inspection Report No. 50-245/88-02 (1/1/88 - 2/8/88),

transmitted by hRC letter from L. H. Bettenhausen to E. J.

Mroczka, dated March 4, 1988.

(3) NRC letter from K. R. Goller to D. C. Switzer of NNEC0, dated November 14, 1975.

(4) NNEC0 letter from D. C. Switzer to K. R. Goller of NRC, dated November 14, 1975.

(5) NRC letter from G. Lear to D. C. Switzer of NNEC0, dated March 3, 1977.

(6) NNEC0 letter from D. C. Switzer to G. Lear of NRC, dated July 29, 1977.

(7) NNEC0 letter from D. C. Switzer to D. L. Ziemann of NRC, dated May 31, 1978.

(8) NNEC0 letter from W. G. Counsil to D. L. Ziemann of NRC, dated September 20, 1978.

(9) NNEC0 letter from W. G. Counsil to D. M. Crutchfield of NRC, dated May 9, 1980. ,

(10) NNECO letter from W. G. Counsil to D. M. Crutchfield of NRC, dated September 9, 1980.

(11) NNEC0 letter from W. G. Counsil to D. M. Crutchfield of NP.C, dated October 15, 1980.

(12) NNEC0 letter from W. G. Counsil to D. M. Crutchfield of NRC, dated November 6, 1980.

(13) NRC letter from B. H. Grier to W. G. Counsil of NNEC0, dated February 26, 1981.

(14) NRC Letter LS05-82-10-022 from J. J. Shea to W. G. Counsil, dated October 8, 1982.

(15) NNEC0 letter from E. J. Mroczka to U.S. NRC, Document Control Desk, dated April 29, 1988.

(16) NRC letter LS05-85-05-012 from J. A. Zwolinski to J. F. Opeka, dated May 10, 1985.

(17) NNEC0 letter from J. F. Opeka to C. I. Grimes of NRC, dated November 19, 1986.

. (18) NNEC0 letter from E. J. Mroczka to U.S. NRC, Document Control Desk, dated April 28, 1987.

Docket No. 50-245 B12968 Attachment 1 Millstone Unit No. 1 Containment Isolation Valves July 1988

r Attachment 1 Page 1 List of Millstone Unit 1 Containment Isolation Valves Penetration No. Valve Number X-7A thru D MS-1A to 1D MS-2A to 2D X-8 MS-5, MS-6 X-9A & B N 10A & B

% 9A & B X-10A IC-2 X-11B IC-3, IC-6, IC-7 X-12 SD-2A & B PAS-17 & 20 X-14 CU-2, CU-2A, CU-3, & CU-5 X-15 CU-29 & CU-28 X-16A & B CS-5A & B X-17 HS-5 & HS-4 X-18 SS-3 & SS-4 X-19 SS-13 & SS-14 X-20 W-66, W-67, & N-64 X-21 SA-345 & SA-344 X-22 AC-162 & AC-50 X-23 RC-6 X-24 RC-15 X-25 AC-7, AC-8, AC-9, AC-10, AC-11, AC-12, AC-198, AC-196, AC-206, AC-199, AC-197, & AC-205

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Attachnent 1 Page 2 List of Millstone Unit 1 Containment Isolation Valves Penetration No. Valve Number X-26 AC-4, AC-5, AC-17, AC-40, & AC-41 X-27 a thru f LPr-18A, LPT-14, LPT-16, LPT-21A X-28a thru f LPT-2, LPT-10A, LPT-4A, LPT-6A, &

LPT-8A X-29a thru f LPT-8B, LPT-108, LPT-4B, LPT-6B X-30f RR-25A X-31a thru f RR-63A, RR-55A, RR-61A,LtR-57A, RR-59A, RR-53A X-32 a thru f RR-63B, RR-55B, RR-59B, RR-57B, RR-61B, RR-53B X-33 IC-21, IC-22, IC-25, IC-26, LPT-21B,

& LPT-19B X-34f RR-25B X-36 AC-139, AC-140 X-35 A thru D TIP ball, squib, and parge valves X-37A & D AC-127A thru o X-37A thru D and SW-IN, SW-2N, SW-25, SW-1S, X-38A thru D SW-3N, SW-4N, SW-3S, SW-4S X-39A & B LP-15 & a X-40A RR-47A & B, RR-51A & B X-40B RR-81B, RR-83B, RR-85B, RR-87B, RR-89B, RR-91B X-40C RR-80A, RR-83A, RR-85A, RR-87A, RR-89A, RR-91A ,

X-40D RR-93A, RR-95A, RR-97A, RR-99A, PR-101A, RR-103A

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Attachment 1 Page 3 List of Millstone Unit 1 Containment Isolation Valves Penetre. tion No. Valve Number X-42 SL-7, SL-8 X-43 LP-10A X-44 a, b, e, f RR-45A & B, RR-43B, RR-49B X-45 LP-10B, SD-5 X-47 RR-37, RR-36 X-49 RR-93B, RR 15B, RR-978, RR-998,,

RR-101B, 3R-103B X-202E AC-11, AC-12, AC-8, AC-10 X-202C AC-194, AC-195 X-204A to C LP-2A to D, CS-2A & B X-205 AC-6, AC-1A & B, AC-58, AC-67, AC-69, AC-4, AC-17, AC-2A & B, AC-133, and AC-134 X-206A to D AC-28A & B, AC-27A & B X-209A & D AC-29A & B X-210A & B LP-43A & B, LP-24 A thru D, CS-14 A&B X-211A & B LP-14A & B, PAS-24, PAS-25 X-212 CU-68, CL'-69 X-216 AC-25A X-217 AC-21, AC-22 X-250 AC-26A X-251 AC-25B X-252 AC-26B

Docket No. 50-245 B12968 Attachment 2 Millstone Unit No. 1 Containment Isolation Valve Designations Differing from Appendix A General Design Criteria July 1988

MILIE10tE WIT 1 C0tfDuMG!NF ISOLATIN VALVE DESIGNATIONS DIFFERING FROM APPL!NDIX A GDEERAL DESIGN CRI'IERIA Penetration No. Descriptions X-10A & X-11B NNECO considers the isolation condenser a closed loop. Therefore, only IC-2 & 3 are CIVs (IC-1 & 4 are no longer considered CIVs).

X-12 NNECO considers shutdown cooling a closed loop; only SD-2A & B are treated as CIVs.

Both post accident sampling system CIVs are located outside containment.

X-16, X-204 A thru C, X-45 In SEP VI-4 (NUREG-0824, Section 4.20.3), the X-39, X-43, X-210A & B, NRC identified ECCS systems as closed loops; X-211 A & B the NRC also rtated containment isolation would be achieved because certain leakage detectors were available. Single CIVs are designated in these penetrations. Note: The PASS has two CIVs at X-211A. Both CIVs are cutside containwnt. X-210A and B have single check valves (CS-14A and B) as CIVs outside containment. In NUREG-0824, Section 4.20.4, the NRC classified X-39 and X-211 as c'.osed loops per GDC-57. However, the NRC then evaluated double valve isolation configurations at each penetrati m .

X-212 he branch to the iso-condenser trap drains is considered a closed loop. This closed loop is considered a boundary in addition to CU-69. All CIVs are outside the torus.

X-217, X-206, X-209, X-216 hese branches are considered extensions X-250, X-251, X-252, X-220 of containment.

X-221, X-37A, X-37D, X-38A X-38D X-24 This system is a closed loop; a single CIV has been designated.

l X-18 & 19 Both containment valves are outside the containment.

MILIBIONE LNIT 1 CCNTAIl@GNP ISO. *ATION VALVE DESIGikTICNS DIFFERING FROM APPDOIX A GDIERAL DESICM CRITERIA Penetration No. Descriptions X-23 This system is a closed loop; a single CIV inside containment has been designated. his was evaluated in SEP, but final NRC concurrence was never obtained.

X-25, X-26, X-205 he location of all atmospheric control system valves outside containment was approved in SEP Topic Vl-4.

(NUREG-0824).

X-47, X-36, X-205 Both CIVs are located outside containment; SEP VI-4 (NUREG-0824) Section 4.20.4 implied this configuration is generally acceptable based on Palisades PRA.

X-10A & 11B The iso-condenser vent line through IC-6 and IC-7 is isolated during a DBA. Wese valves are not true CIVs; however, they do receive a group isolation signal.

X-30F and X-34F Ihe NRC assumed these were instrument lines with excess flow check valves in SEP Topic VI-4; however, they are recirculation pump seal flush lines with single boundary check valves outside containment.

X-37A thru D and X-38A The scram discharge volumes and associated thru D CIVs are all outside containment.

X-42 We NRC approved two check valves in series as CIVs in SEP Topic VI-4 (ref. NUREG 0824 Section 4.20.6).

X-20 NNECO maintains these valves locked and administratively controlled.

X-9A & X-9B We two check CIVs in series were evaluated and approved in SEP Topic VI-4 (ref. NUREG 0824 Section 4.20.6).

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• MILLS'ITNE LMIT 1 CCNEADGENT ISOIATICN VALVE DESIGOLTICNS DIITERING FROM APFDOLT A GENERAL DESIGN CRI'll!RIA Penetration No. Descriptions X-25, X-26, X-202E, X-205 he atmospheric control system CIVs are X-202G, outside containment.

X-27, X-28, X-29, X-31, Instrument lines with excess flow check X-32, X-33, X-40, X-49, valves are covered tuder Reg. Guide 1.11.

X-44 X-213 A & B These construction drains are treated as extensions of the primary containment (i.e.,

no CIVs designated).

X-35A thru 35E All TIP system CIVs are outside containment; the purge check valve is a single boundary; the TIP insertion tubes have two boundary valves outside containment.

X-37A to X-37D,X-38A to There are no C/Vs in the CRD insert and X-38D withdrawal lines. These high integrity lines demonstrate their leak tightness on a continuous basiT.

X-204A to X-204C %ere are LPCI pu@ s bearing cooling lines off of these penetrations that do not have CIVs. This configuration is being prioritized in ISAP.

Miscellaneous Small Many sm il branches off of piping that Branches penetrates containment evntain valves that are locked and administratively controlled, h is configuration was judged to be accept-able by the NRC in NUREG-0824 4.20.1.

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