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NRC INSPECTION MANUAL DI

INSPECTION PROCEDURE 70323

CONTAINMENT LEAK RATE TEST RESULTS EVALUATION

PROGRAM APPLICABILITY: 2513, 2515 (BASIC)

70323-01 INSPECTION OBJECTIVE

This procedure is designed to verify that the licensee has

adequately performed, reviewed, and evaluated preoperational and

operational Type A containment tests [containment integrated leak

rate test (CILRT)] and Type B or C containment tests [local leak

rate test (LLRT)] for preoperational and operational plants.

70323-02 INSPECTION REQUIREMENTS

02.01 Review the licensee's report titled "Reactor Containment

Building Integrated Leak Test" to verify compliance with respect to

the following items:

a. Type A Test

1. Verify that the "as found" [(AF) - initial containment

condition] and "as left" [(AL) - final containment

condition] results for each Type A test sequence performed are submitted, as applicable. The AF condition is

not applicable to preoperational CILRTS.

2. Determine if the test results and the analyses and

interpretation of the leakage rate test data adequately

characterize the acceptability of the containment for the

AF and AL Type A tests, including meeting the following

criteria:

(a) Verify that the required leakage rate computations

were properly performed.

(b) Ensure that the total measured leakage rate (Ltm/Lam)

meets the required leakage rate acceptance criteria.

(c) Verify that Ltm(Lam) was corrected for random

instrument errors.
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(d) Determine if the proper LLRT correction factor was

used to calculate the AF and AL leakage rates.

3. Review the results and analyses of the supplemental

verification test used to demonstrate Type A test

validity.
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4. Ensure that Type A test which failed to meet the acceptance criteria is separately reported with the following

information included:

(a) an analysis and interpretation of the test data

(b) the least-squares fit of the test data

(c) the test instrumentation error analysis

(d) a description of the structural conditions of the

containment or components which contributed to the

test failure

5. Check that the preoperational leak rate test report

includes a schematic of the leakage rate measurement

system, a description of the instrumentation used, and a

discussion of the applicable test program.

b. Type B and C Tests

1. Verify that the results of Type B and C LLRTs performed

since the last Type A test meet the required acceptance

criteria.

2. Determine if the licensee has conducted an adequate

summary analysis for the LLRTs performed.

3. Ensure that each Type B or C test that failed to meet the

acceptance criteria is separately reported with the

following information included:

(a) an analysis and interpretation of the test data

(b) the test instrumentation error analysis

(c) a description of the component condition which

contributed to the test failure.

c. Containment Structural Deterioration. Evaluate any reported

containment structural deterioration and the corrective

actions taken to correct it.

d. Time Requirement. Verify that the licensee's report was

submitted approximately 3 months after the test was conducted.

02.02 Verify that the Type A test leakage rate calculated during

the performance of IP 70313 from the test data is consistent with

the licensee's reported result.

70323-03 INSPECTION GUIDANCE

General Guidance. This inspection procedure is designed to evaluate

the acceptability of the containment integrated leakage rates as

reported by the licensee for both the AF and AL conditions. These

results will provide a good characterization of not only the current
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containment leak-tight integrity but also of this condition with

respect to time (i.e., how the leak rate changes while the

containment ages). This information is necessary to ensure that the

containment can and will maintain its leak-tight integrity in the

event of a design basis loss of coolant accident.

03.01 Specific Guidance. This section is provided to supply a

more detailed explanation of the source and method of implementation

for each specific inspection requirement. The references for the

applicable sources given in parenthesis after each requirement are

listed in section 70323-04 of this procedure.

a. Inspection Requirement 02.01a1. In performing the periodic

Type A test, the licensee is required to determine both the

AF and AL conditions of the containment system. The

preoperational Type A test requires the determination of only

the AL condition. The AF condition is that at the time of

reactor shutdown proceeding the Type A test. This test is

performed to disclose the normal state of repair of the

containment system and to determine if there is any abnormal

deterioration occurring. The AL condition is that at the

completion of the test sequence. This test is performed to

ensure that the containment system is in a satisfactory state

of repair prior to recommencing power operations.

(refs: c-sections III.A.1 and V.B.2. and V.B.3., d, and

h-sections 4.1 and 4.2)

b. Inspection Requirement 02.01a2(a)

1. Two methods of performing the Type A test are currently

approved: the absolute method and the reference-vessel

method. However, due to inherent difficulties in

performing the latter, the absolute method is used

exclusively.

2. Review the calculations included in the results and the

analyses and interpretation sections. Verify that the

basic calculations included are current and that the

figures used make sense (i.e., order of magnitude).

Verify that unit conversions (e.g., wt%/day, % allowable, SCFM, and SCCM) are included and were performed

properly.

(refs: c-section V.B.2. and 3., h-section 7, and k).

c. Inspection Requirement 02.01a2(b). For peak (Pa) and reduced

(Pt) containment internal pressures the associated maximum

allowable leakage rates (La/Lt) are defined in the licensee's

technical specifications (TS) and operating license. The

acceptance criteria are at a minimum as conservative as the

following equation:

Lam (Ltm) < 0.75 La(Lt)

and for the preoperational peak pressure test, Lam should also

be less than or equal to Ld, where
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Lam = total measured containment leakage rate at Pa

Ltm = total measured containment leakage rate at Pt

Ld = design leakage rate at Pa

The values for Lam(Ltm) in the above equation must include the

LLRT correction factor and a value for random instrument error

when determining if the CILRT was satisfactory.

(refs: c-section III.A)

d. Inspection Requirement 02.01a2(c). Licensees are required to

correct Ltm (Lam) for random instrument errors through

addition of the calculated absolute value of the error.

Though no particular method is generally required, some

licensees have committed in their TS to the application of

Upper Confidence Limits (UCL) set at a 95% probability in

order to account for the instrument error. The UCL is a value

calculated by measuring the standard deviation from the slope

of the least squares linearization of the test data within

which a certain fraction of all values may be reasonably

expected to lie.

(refs: c-section III.A.3(c), k-section 5.74)

e. Inspection Requirement 02.01a2(d)

1. If repairs and/or adjustments were performed on

containment components during this outage prior to the

completion of the Type A test, the change in local leak

rate for these components must be used to determine the

total integrated leak rate. This is done by conducting

LLRTs on the affected components to determine the minimum

pathway leakage before and after the repairs/adjustments.

The difference in minimum pathway leakage is then added

to the Type A test result to obtain the required AF

result. The minimum pathway leakage would be the smaller

leakage rate for in-series valves tested individually,

one-half the leakage rate for in-series valves tested in

parallel. This differential of the leakage is the LLRT

correction factor.

2. If the minimum pathway leakage for a penetration cannot

be determined, then the AF Type A test is considered a

failure.

3. If a barrier cannot be tested (e.g., will not hold

pressure) in the direction that pressure would normally

be applied when in performance of its safety function,

then it may be validly tested from the opposite

direction. However, it must be proven that the test

results obtained in the opposite direction will provide

equivalent or more conservative results. This proof

should be included in the test report.

4. All LLRTs performed to compensate a Type A test for

repairs/adjustments shall be performed at the Type A test

pressure.
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(refs: c-sections III.A and B, k-section 6.)

f. Inspection Requirement 02.01a3

1. A supplemental integrated leak rate verification test is

required to be performed to validate the Type A test. No

set method of verification test is prescribed, but the

test must be conducted over a sufficient duration to

yield a change in leakage rate from the Type A test

result. The leakage rate shall be determined from the

slope of the linear least squares fit of the graph of

leakage rate versus time. Enough data points must be

taken to give an accurate leakage rate result. To prove

the Type A test acceptable, the following criteria must

be met:

*Lam(Ltm) - (Lc - Lo)* 0.25 La(Lt), where

Lam(Ltm) is the raw integrated leakage rate obtained with

no corrections for instrument errors or LLRT correction

factors included unless repairs or adjustments were made

in between the times of the performance of the two tests,

Lc is the composite leakage rate measured during the

verification test, and

Lo is the known orifice leakage rate or the negative of

the controlled pump back injection rate of the

verification test.

2. The comparison of the Type A test results and the

verification test results should be done using raw data.

No instrument error or LLRT correction factors should be

included unless repairs or adjustments were made in

between the times of performance of the two tests.

(refs: c-sections III.A.3(b), h, k).

g. Inspection Requirement 02.01a4. Each Type A (AF and AL) test

failure must be addressed in a separate section of the

licensee's report. Adequate analysis must be performed to

determine if the cause was a "single time" failure or a

chronic problem. Test failures will impact the scheduling for

future Type A tests.

(refs: c-section III.A.6 and V.B.3).

h. Inspection Requirement 02.01a5. A statement as to which leak

rate test method is used is essential as this method shall be

normally used for all operational Type A tests.

(refs: c-section III.A.3.(b) and V.B.2).

i. Inspection Requirement 02.01b

1. LLRTs are not always independent of CILRTs. Due to the

relationship between these tests as outlined in 03.01e1,
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extensive information is required to determine the effect

that local leak rates and singular component

deterioration have on the overall containment integrated

leak rate.

2. If abnormal deterioration of containment structural

components is discerned, an evaluation of the possible

causes should be carried out in an effort to ensure the

maintenance of proper containment integrity.

(refs: c, h, and k).

j. Inspection Requirement 02.01b1

1. The combined leakage rate for all penetrations and valves

subjected to Type B and C tests during a complete leak

rate test sequence shall be less than 0.60 La. A

complete leak rate test sequence would be that in which

every boundary required to be Type B or C tested by the

TS, has been tested.

2. If any valve or penetration cannot be pressurized for a

Type B or C test, then the sum of the LLRT leak rates is

by definition > 0.60 La.

(refs: c-sections III.B.3 and III.C.3)

70323-04 REFERENCES

a. 10 CFR 50.73.

b. 10 CFR 50, Appendix A, Criteria 52, 53, 54, 55, 56, and 57.

c. 10 CFR 50, Appendix J.

d. Memorandum for R. J. Mattson to J. H. Sniezak, "Clarification

of Appendix J Requirements - Definition of Type A Test

Failures," January 11, 1982.

e. Regulatory Guide 1.11, "Instrument Lines Penetrating Primary

Reactor Containment," March 10, 1971.

f. Regulatory Guide 1.141, "Containment Isolation Provisions for

Fluid Systems," April 1978.

g. ANSI N18.1-1971, "Selection and Training of Nuclear Power

Plant Personnel."

h. ANSI N45.4-1972, "Leakage - Rate Testing of Containment

Structures for Nuclear Reactors."

i. ANSI/ANS-3.1 1981, "Selection, Qualification, and Training of

Personnel for Nuclear Power Plants."

j. ANS-56.2 ANSI N271-1976, "Containment Isolation Provisions for

Fluid Systems."
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k. ANSI/ANS-56.8-1981, "Containment System Leakage Testing

Requirements."

l. Topical Report BN-TOP-1, Revision 1, "Testing Criteria for

Integrated Leakage Rate Testing of Primary Containment

Structures for Nuclear Power Plants," November 1, 1972,

Bechtel Corporation.

END