ML093630929

Containment Leakage Rate Testing,Indian Point Unit 2, Technical Evaluation Rept

ML093630929
Person / Time
Site:	Indian Point
Issue date:	04/25/1980
From:	Delgaizo T Franklin Institute
To:	Huang Y NRC/AEOD
Shared Package
ML093630928	List: ML093630929 ML19275J210
References
CON-NRC-03-79-118, CON-NRC-3-79-118 NUDOCS 8007010781, TER-C5257-024, TER-C5257-24
Download: ML093630929 (13)

Text

U. 0 TECHNICAL EVALUATION REPORT CONTAINMENT LEAKAGE RATE TESTING INDIAN POINT UNIT 2 I

NRC DOCKET NO. 50..-2 47 NRC TAC NO. 10912 FRC PROJECT C5257 NRC CONTRACT NO. NRC-03-7-118 FRTASK 24 Prepared by Franklin Research Center The Parkway at Twentieth Street Author: T. J. De1QLZ0o Philadelphia, PA 19103 FRC Group Leader: T-j J.1 n Prepared for Nuclear Regulatory Commission Washington, D.C. 20555 Lead NRCEngineer Y.. S. Huang APRIL 25, 1980 This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, or any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for any third party's use, or the results of such use, of any Information, apparatus, product or process disclosed In this report, or represents that its use by such third party would not infringe privately owned rights.

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TECHNICAL EVALUATION REPORT CONTAINMENT LEAKAGE TESTING INDIAN POINT UNIT 2 CONTENTS Section Title Page

. 1

1.0 BACKGROUND

. 1 2.0 REVIEW CRITERION . . . . . .

3.0 TECHNICAL EVALUATION

. . . .

• 2 3.1 Request For Exemption . . .

• 2 3.1.1 Component Cooling Water Supply and Return Line to the Recirculation Pump Motors . 2 3.1.2 Component Cooling Water Return Lines from the Residual Heat Exchangers . 3 3.1.3 Air Supply Line to the Weld Channel and Penetration Pressurization System .

• 3 3.2 Proposed Technical Specification Changes . 4 3.2.1 Containment Test (Specification 4.4) . . 4 3.2.1.1 Integrated Leakage Rate (TS 4 .4.A) 5 3.2.1.2 Sensitive Leakage Rate (TS 4.4 .) 5 3.2.1.3 Airlock Tests (TS 4.4.C) . * . 5 3.2.1.4 Containment Isolation Valves (TS 4.4.D). . 7 3.2.1.5 Containment Modifications (TS 4.4.E) 8 3.2.1.6 Reporting of Test Results (TS 4.4.F) 9 3.2.1.7 Annual Inspection (TS 4.4.G) .9 3.2.1.8 Residual Heat Removal System * . 9 (TS 4.4.H) .

4.0 CONCLUSION

S 10

.. . . . .. . . . 11

5.0 REFERENCES

Iuti rarnkfin Research Center A Dmsion of The Frankfin In mwue

U 0 TECHNItAL EVALUATION REPORT CONTAINMENT LEAKAGE TESTING INDIAN POINT UNIT 2

1.0 BACKGROUND

On August 7, 1975 [1], the NRC requested Consolidated Edison Company of New York, Inc. (CEC) to review the containment leakage testing program for Indian Point Unit 2 (IP-2) and to provide a plan for achieving full compliance where necessary, including appropriate design modifications, changes to technical specifications, and requests for exemption from the requirements pursuant to 10CFR50.12.

On September 9, 1975 [2], CEC replied that modifications to the IP-2 technical specifications would be necessary. On April 14, 1976 [3], CEC submitted a request for exclusion of six valves from the Type C testing requirements of Appendix J. On April 16, 1976 [4], CEC submitted an Application for Amendment to Operating License DPR-26. Subsequently, on December 16, 1976 [5], CEC submitted Amendment 1 to Application for Amendment to Operating License DPR-26 which modified and supplemented the submittal of Reference [4].

This report provides a technical evaluation as to the acceptability of the requests for exemption from the requirements of Appendix J submitted by CEC in Reference [3] and also provides a technical evaluation of the proposed technical specification changes submitted by References [4] and [5] as they relate to the containment leakage testing requirements of Appendix J.

2.0 REVIEW CRITERIA The criteria by which the technical evaluation was conducted included 10CFRS0, Appendix J, Containment Leakage Testing, and ANSI N45.4-1972, Leakage Rate Testing of Containment Structures for Nuclear Reactors. Where applied to the following evaluations, the criteria are either referenced or are briefly stated where necessary to support the result of the evaluations. Furthermore, in recognition of the plant-specific conditions which could lead to requests for exemption rot explicitly covered by the regulations, the NRC directed that the technical review 1PL:nkfin Research Center A Dmun of The Frankijn Instute

U 0 constantly emphasize safety aspects and the basic intent of Appendix J that potential containment atmospheric leakage paths be identified, monitored and maintained below established limits.

3.0 TECHNICAL EVALUATION

3.1 REQUESTS FOR EXEMPTION Reference [3] requested exemption from the requirements of Appendix J in order to exclude four valves in the component cooling water (CCW) system and two valves in the weld channel and penetration pressurization system (WC and PPS) from the containment leakage testing program. The following sections provide an evaluation of these requests.

3.1.1 Component Cooling Water Supply and Return Lines to the Recirculation Pump Motors CEC requested that Valves 753H and 753G (CCW supply and return line isolation valves to the recirculation pump motors) be excluded from testing in accordance with Appendix J. CEC's basis for this request is that during both normal plant operation and post-accident conditions, these manually oper ated valves are in the open position to provide component cooling water to the recirculation pumps located within the containment. CEC also stated that the portion of the CCW system within the containment is a closed system and that the portion of the CCW system outside containment supplying cooling water to the pumps is also a closed system and monitored for radioactivity. In view of the above, CEC concluded that a Type C test of these valves, as required by Appendix J, would serve no particular purpose.

Evaluation. The requirements for Type C testing of containment isolation valves are prescribed by Sections II. and III.A.l.(d) of Appendix J. Based upon CEC's statement that Valves 753H and 753G are normally open manual valves in a

-closed system inside containment which is designed for continuous operation during both normal and emergency conditions (and therefore not liable to rupture as result of a LOCA), Type C testing is not required by either Section II.H or III.A.l.(d). Consequently, FRC finds that the proposed exclusion from Type C testing for Valves 753H and 753G is acceptable because the regulation does not require testing. No exemption from the requirements of Appendix J is necessary.

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3.1.2 Component Cooling Water Return Lines from the*Residual Heat Exchangers CEC requested that Valves MOV-822A and MOV-822B (CCW return line isolation testing in accordance valves from the residual heat exchangers) be excluded from are closed with Appendix J. CEC's basis for the request is that these valves receiving an during plant operation and open during accident conditions (after piping opening signal). CEC further stated that the portion of the CCW system system out inside containment is a closed system and that the portion of the CCW is also side containment supplying cooling water to the residual heat exchangers Type C a closed system and monitored for radioactivity. CEC concluded that a purpose.

test of these valves, as required by Appendix J, would serve no particular EvaZuation. The requirements for Type C testing of containment isolation valves are prescribed by Sections I1.11 and III.A.l.(d) of Appendix J. Furthermore, perform Section II.B defines a containment isolation valve as one relied upon to a containment isolation function.

These valves are in a closed system inside containment which is designed not to remain operational throughout the post-accident period (and therefore system liable to rupture as result of a LOCA). Furthermore, the design of the or is such that even if one of the isolation valves fails to open on signal were to fail shut after opening, the shut valve is always pressurized with water thorugh the common return header. Consequently, regardless of the position of the valves or other possible single active failures within the CCW system, Valves MOV-882A and MOV-822B are not relied upon to perform a containment isolation function since no path exists for the leakage of con tainment atmosphere and therefore Appendix J does not required that they be tested.

FRC finds that the proposed exclusion from Type C testing for Valves MOV-882A and MOV-882B is acceptable because the regulation does not require testing. No exemption from the requirements of Appendix J is necessary.

3.1.3 Air Supply Line to the Weld Channel and Penetration Pressurization System CEC requested that Valves PCV-1111 (two valves, one in each penetration supplying air to the WC and PPS) be excluded from testing in accordance with Appendix J. CEC's basis for this request is that these manual isolation valves

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w 0 are required to be in the open position to assure continuous pressurization of the system. CEC further stated that the system is considered to be a closed system inside containment and that the supply of air to Valves PCV-1111 is always higher than peak accident pressure within containment and therefore, no potential exists for leakage from the contianment through these valves.

CEC concluded that Type C testing for these valves would serve no purpose.

EvaZuation. The requirements for Type C testing of containment isolation valves are prescribed by Sections II.H and III.A.l.(d) of Appendix J. These sections do not require Type C testing of manual valves in closed systems inside containment which are not liable to rupture as result of a LOCA.

Review of the IP-2 FSAR for the WCand PPS indicates that the system is designed to engineered-safety-feature-system criteria (and therefore not liable to rupture as result of a LOCA), that it is a closed system inside con tainment, and that it has sufficient redundancy in the supply of air to provide air at pressures in excess of peak calculated accident pressure throughout the accident. This review confirmed CEC's contention that there is no potential for leakage of containment atmosphere through these isolation valves. The tested.

review also revealed that Appendix J does not require that these valves be Therefore, FRC finds that the exclusion of Valves PCV-1111 (two valves, one in each penetration supplying air to the WC and PPS) from Type C testing No is acceptable because the regulation does not require that they be tested.

exemption from the requirements of Appendix J is necessary.

3.2 PROPOSED TECHNICAL SPECIFICATION CHANGES Reference [4] forwarded an Application for Amendment to Facility Operating License DPR-26. Reference [5] forwarded Amendment 1 to that application. Only those portions of Amendment 1 which are applicable to this evaluation have been

.considered in this report.

3.2.1 Containment Tests (Specification 4.4)

CEC's purpose in providing the proposed revision to this part of the technical specification (TS) was to revise the TS in accordance with the requirements of Appendix J. The FRC's evaluation of each major subsection of TS 4.4 is presented below.

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iDote T 4. 4 -A)-

3.21.1i containment integrated'leakage conducted over a that the Proposed TS 4.4.A requires of Pa (47 psig),

be a pressure over performed at equal intervals rate test be 3 approximately nducted at that the measured leakage rate not r period, a t ls Cpcfies each ot

/ dyO e rayn nt atmosphere (ere- La also equals speci. *.

acho 10.ea La exceed 0.75 La (where i

at 47 psig). in conformance with Section II.A of EVaZUtoig) . Proposed TS 4.4.A is peak of ANSI N45.41 97 2 . The value of Pa is the Appendix J and the procedures was and the value of La pressure for the IP-2 contai1ent, the levels calculated accident well below public exposure would remain determined to ensure that are basis accident. Tese proposed revisions a design of loCFRl00 during therefore acceptable.

Sitive Leakae Rate (TS4.4.B) d tests be performe

.4.,D leakage rate that sens 6.....

Proposed TS 4.4.B requires channels,;and certain o47e-gasketed with the containment penetrations, weld 5 at a p re of 47 psig and ohinimu interspace seals and isolation-alves every other refueling at a frequency of at least that they be conducted acceptance than 3 years. It also imposed an greater but in no case at intervals free volume per day.

containment 0.2% of the criteria of of Appendix J, proposed TS 4.4.BThe meets the requirements specification is therefore EValu~ton.

III.B.l-(c and iII.D.2 proposed Section acceptable.

A irlock Tests 4.4.C)

(TS 3.2.1.3 airlock test to be performed proposed TS 4.4.C requires a containment months with a verification Prn p sse of 47 psig (Pa) once every six c-orsasuoclintearok at a minimu~m pressureof4ps&(a the airlock of the double-gasketed airlock-oor seals upon closing at 47 psig required.

integrity is door when containment

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EvaZuation. Proposed TS 4.4.C meets the requirements of Appendix J,Section III.D.2 in that the airlocks are being tested at peak calculated accident pressure (Pa) every six months. However,Section III.D.2 also requires that airlocks be tested at Pa after each use. CEC's proposal to verify the airlock door seals following each use by pressurizing between the double-gasketed seals to a pressure of Pa requires an exemption from the requirements of Section III.D.2.

Experience has shown that for some operating reactors, it is impractical to leak test an airlock at peak calculated accident pressure (Pa), especially when frequent airlock usage is necessary. Testing is a time consuming process and may result is unnecessary exposure to operating personnel. Since the inner door is exposed to pressure in the direction opposite that of the pressure which would exist under accident conditions, strong-backs or other mechanical adjustments are often necessary to prevent the inner door from unseating and preventing meaningful test results. The employment of strong backs or other mechanical adjustments may even cause a degradation of the airlock operating mechanisms which could eventually lead to reduced airlock reliability.

Since 1969, there have been approximately 40 instances where airlock leak tests have resulted in greater than allowable leak rates. However, they were all caused by the failures of door seals, not by the entire doors.

Testing at a pressure of Pa between the double-gasketed seals at IP-2 is an acceptable method to detect door seal leakage while at the same time eliminating the impracticalities, and perhaps reduction of reliability, associated with full airlock testing at Pa.

In view of the above discussion,, FRC finds that CEC's proposal to perform a verification of airlock door seals at 47 psig by pressurizing between the double-gasketed seals is an acceptable alternative to performing a Type B test of. the airlock after each use and that an exemption from this requirement of Appendix J is acceptable. Consequently, proposed TS 4.4.C is also acceptable.

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~nkWin Research Center A Dmsxw: oi The Frarddin Ikutule

3.2.1.4 Containment Isolation Valves (TS 4.4.D)

Proposed TS 4.4.D provides for the testing of containment isolation valves, the frequency of the tests, the acceptance criteria, and the addition of valves to the testing list. Each of these provisions are separately evaluated below.

Testing of Containment Isolation Valves Proposed TS 4.4.D requires that isolation valves be tested in accordance with Table 4.4-1. Table 4.4-1 provides a listing (9 pages) of containment isolation valves, the designated test medium, and the minimum test pressure.

The table also indicates which valves are sealed by water systems or by the weld channel and penetration pressurization system. The test pressures are listed as 47 psig (Pa) or 52 psig (110% Pa) in the case of seal water systems.

EvaZuation. This portion of TS 4.4.D is in accordance with Appendix J,Section III.C and therefore is acceptable.

Frequency of the Tests Proposed TS 4.4D requires Type C tests, including the tests .of the isolation valve seal water system and the weld channel and penetration pressurization system, be performed at intervals no greater than 2 years.

EvaZuation.Section III.D.3 of Appendix J requires that Type C tests be performed during each reactor shutdown for refueling but in no case at intervals greater than 2 years. Since reactor shutdowns for refueling occur, on the average, every 12 to 15 months and since it is impractical to perform these tests in periods other than refueling shotdowns, the basic effect of Section III.D.3 and proposed TS 4.4.D are the same. However, proposed TS 4.4.D is not conservative in relation to the requirements of Section III.D.3 since circumstances can arise in which the frequency of performing Type C tests as required by proposed TS 4.4.D can exceed the frequency between refueling shutdowns as prescribed by Section III.D.3.

Consequently, FRC finds that this portion of proposed TS 4.4.D is not acceptable unless the frequency of the tests is modified to be exactly in accordance with Appendix J, namely that Type C tests be performed during each reactor shutdown for refueling but in no case at intervals greater than 2 years.

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Acceptance Criteria Proposed TS 4.4.D requires that the combined leakage rate of the Type B and Type C tests (other than those Type C tests performed as part of the tests of the seal water systems) be less than 0.6 La. The proposed TS also requires that the leakage rate into the containment for isolation valves sealed by the service water system not exceed 0.36 gpm per fan cooler and that the leakage rate of the isolation valve seal water system not exceed 14,700 cc/hr.

Evaluation. The limit of the combined leakage rate (less than 0.6 La) is in accordance with Section III.C.3 of Appendix J. The limitation of leakage into the containnent of 0.36 gpm per fan cooler will permit a full 12 months of post-accident recirculation without flooding the internal recirculation pumps. The limitation of 14,700 cc/hr for the isolation valve seal water system is consistent with fe capacity of the system supply tank.

The system is designed to provide a supply of 30 days of water post-accident as required by Section III.C.3 of Appendix J. Consequently, FRC finds that this portion of proposed TS 4.4.D is acceptable.

Addition of Valves to the Testing List Proposed TS 4.4.D permits addition of isolation valves to plant systems without prior licensee amendment provided that a revision to the Table 4.4.-l is included in a subsequent license amendment application.

EvaZuation. Appendix J does not require that the containment leakage testing program be amended prior to any system modifications which effect containment isolation. Appendix J does require that any modifications after to the preoperational containment leak rate testing be followed by appropriate integrated leakage rate or local leakage rate testing. This requirement is imposed by proposed TS 4.4.E below. Consequently, FRC finds that CEC's proposal to include plant modifications in subsequent license amendment applications for revision to Table 4.4-1 to be acceptable.

3.2.1.5 Containment Mondifications (TS 4.4.E)

Proposed TS 4.h. requires that a containment integrated leakage rate test or a local leak rate test be performed following a modification or replace ment of components of the containment after the initial preoperational testing.

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Evaluation. Proposed TS 4.4.E complies with Appendix J,Section IV.A and is therefore acceptable.

3.2.1.6 Reporting of Test Results (TS 4.4.F)

Proposed TS4.4.Frequires that integrated containment leakage test results be submitted to the NRC in accordance with Appendix J.

Evaluation. Proposed TS 4.4.F requires reporting requirements as specified in Appendix J and is therefore acceptable.

3.2.1.7 Annual Inspecticn_(TS 4.4.G)

Proposed TS 4.4.G requires that a visual inspection with appropriate corrective action be performed at each refueling shutdown and prior to an integrated leakage rate test in order to uncover evidence of deterioration which might affect either containment structural integrity or leak-tightness with repairs as required.

Evaluation. Proposed TS 4.4.G complies with Appendix J,Section V.A and is therefore acceptable.

3.2.1.8 Residual Heat Removal System (TS 4.4.H)

Proposed TS 4.4.H requires that hydrostatic testing of the RHR system be performed at every refueling shotdown with an acceptance criteria of 2 gph and provisions for corrective action as required.

Evaluation. CEC's basis for this specification is to limit off-site exposure due to liquid leakage to insignificant levels relative to those calculated for the design basis accident. From the standpoint of containment atmosphere leakage, this testing, which is in excess of the testing require ments of Appendix J, will further ensure the operability of this engineered

• safety-feature system which provides an additional function of providing the water seals for certain containment isolation valves. Further, experience has shown that liquid limits in the range of 2 gph are indicative of a well functioning closed system of this size and type and provides additional confidence as to the condition of the system. Proposed TS 4.4.H is therefore acceptable with respect to containment atmospheric leakage requirements of Appendix J.

Center rankin Research A Drviwon of The Franldin IfmUrtute

4.0 CONCLUSION

S As a result of the foregoing evaluation, the following requests for by exclusion from the Type C testing requirements of Appendix J, submitted does not CEC in Reference [3], have been found acceptable because the regulation these valves require that they be tested. No exemption is required to exclude from the testing program.

" Exclusion from Type C testing for Valves 753H and 753G, component cooling water return line isolation valves to the recirculation pump motors.

" Exclusion from Type C testing for Valves MOV-822A and MOV-822B, component cooling water return line isolation valves from the residual heat exchangers. .

• Exclusion from Type C testing for Valves PCV-IIII, two valves, one in each penetration supplying air to the weld channel and penetration pressurization system.

Additionally, proposed technical specification 4.4 (Containment Tests)

Facility submitted by CEC in Amendment 1 to the Application for Amendment to found Operating License DPR-26, dated December, 1977 (Reference [5]) has been modification to be acceptable with one acceptable exemption and the need for one as described below.

Proposed TS 4.4.B requires an exemption from the requirements of Appendix J to permit verification of airlock door seals after each use by Pa in pressurizing between the double-gasketed seals at a pressure of lieu of a complete airlock test. FRC has found CEC's proposed exemption request to be acceptable.

Proposed TS 4.4.D should be modified to require that containment isolation valves requiring Type C tests as well as the isolation valve seal water system and weld channel and penetration pressurization system be tested during each reactor shutdown for refueling but in no case at intervals greater than 2 years as opposed to its current wording which requires testing at intervals no greater than 2 years.

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5.0 REFERENCES

[1] NRC Generic Letter from Mr. Karl Goller, Acting Director for Operating Reactors, to Consolidated Edison Company of New York, Inc.,

(CEC) dated August 7,.1975.

[2] CEC letter from Mr. W. J. Cahill, Jr., Vice President to Mr. Karl Goller, Acting Director for Operating Reactors, dated September 9, 1975.

[3] CEC letter from Mr. C. L. Newman, Vice President to Mr.

Karl Goller, Assistant Director, DOR, dated April 14, 1976.

[4] LeBoeuf, Lamb, Leiby, and MacRay letter to Mr. Ben Rusche, Director, NRR, dated April 16, 1976, which forwarded an Application for Amendment to Facility Operating License DPR-26, dated April 14, 1976.

[5] LeBoeuf, Lamb, Leiby, and MacRay letter of December 16, 1977, which for warded Amendment 1 to the Application for Amendment to Facility Operating License DPR-26, dated December, 1977.

'To'1 rnkin Research Center A Division of The Franklin Institute