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NRC INSPECTION MANUAL DI

INSPECTION PROCEDURE 70307

CONTAINMENT INTEGRATED LEAK RATE TEST PROCEDURE REVIEW

PROGRAM APPLICABILITY: 2513, 2515 (BASIC)

70307-01 INSPECTION OBJECTIVES

01.01 Ascertain if the licensee's procedure for the performance

of Containment Integrated Leak Rate Tests (CILRTs) complies with

regulatory requirements, guidance, and licensee commitments.

01.02 Evaluate the technical adequacy of this procedure to

determine containment leak tight integrity.

70307-02 INSPECTION REQUIREMENTS

02.01 Obtain an approved copy of the licensee procedure to be

used in performing the CILRT.

02.02 Review all regulations, licensee commitments, and guidance

pertaining to all CILRTs (Type A tests including both as found (AF)

and as left (AL) conditions).

02.03 Verify that all of the following prerequisites required

to commence the CILRT are included in the licensee's test procedure:

a. For containment structures that are new construction (preparing to undergo the preoperational CILRT) or have undergone

major repairs, the following tests shall be satisfactorily

performed:

Tests

New

Construction

Major

Repairs

Pressure strength test yes yes

Local leak rate test yes yes

Containment isolation

system function test

yes no

b. A general inspection of the accessible portions of the

interior and exterior containment surfaces shall be performed

satisfactorily.
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c. The containment area survey for temperature differentials and

humidity shall be or has been performed with sensing devices

being placed in locations representative of their assigned

subvolumes.
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d. All test instruments are within calibration at the initiation

of the CILRT.

e. Vacuum release devices shall be verified to operate within 10%

of their design pressures for internal and external loading

to ensure containment protection from under pressure.

f. For licensees utilizing the Reference-Vessel method of leakage

rate determination, a reference system leakage measurement

shall be performed by the absolute method to qualify the

system's vacuum retention.

g. The containment structure shall be properly closed out

according to licensee procedure.

02.04 Ensure that each applicable plant system is to be aligned

in accordance with one of the following criteria:

a. All systems required to maintain the plant in a safe condition

shall be operable and in their normal modes.

b. Closed systems that would rupture as the result of a loss of

coolant accident (LOCA) shall be vented to containment.

c. Any system open to containment under post LOCA conditions

shall be opened or vented to containment prior to and during

the test.

d. Any system that would be normally operating under post LOCA

conditions is not required to be vented during the test.

e. Any system or component sensitive to damage from high

pressures or pressure differentials shall be isolated or

removed from containment.

f. All other systems containing fluids that are or may become

pressurized shall be depressurized and isolated from containment.

02.05 Review the CILRT procedure to determine if the procedural

requirements and precautions include the following items:

a. The proper licensee response to all excessive leakage paths

- detected before or during the CILRT

b. The sequencing of the reduced pressure test and the peak

pressure test when conducting the preoperational CILRT (if

performing the reduced pressure test)

c. Containment pressurization requirements:

1. the minimum and maximum pressurization for CILRTs

2. isolation and venting of the pressurization source from

containment upon reaching test pressure
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3. observation of pressure/temperature stabilization prior

to commencing the leakage rate measurement

d. Logging of required test parameters and observations

e. Test data plot for absolute method leakage rate determinations

f. Test duration

g. Supplemental verification test leakage rate and test period

h. Correction for LLRT penalty factors

i. Determination of satisfactory test results for both the AF and

AL conditions.

70307-03 INSPECTION GUIDANCE

General Guidance. The proper performance of a CILRT requires an

indepth test procedure which provides detailed guidance for the

alignment and operation of all systems and equipment inside and

penetrating the primary containment. Without adequately aligning

all systems, artificial leak rate results may be obtained, which in

no way reflect the containment's leak tight integrity. Therefore,

the inspector should develop a thorough understanding of CILRT

practices and procedures prior to the performance of this review.

03.01 Specific Guidance

a. Inspection Requirement 02.01. For the preoperational CILRT,

an approved test procedure satisfying FSAR testing commitments

should be made available by the licensee approximately 60 days

prior to its use.

b. Inspection Requirement 02.02

1. The regulatory basis for CILRTs is found in 10 CFR 50,

Appendix J, ANSI N45.4-1972 and the facility's technical

specifications (TS). Additional guidance is provided in

ANSI/ANS-56.8-1981 as well as IE Bulletins 82-04 and

84-01 and IE Information Notices 79-33, 81-20, 82-40, and

83-23.

2. The term Type A test is synonymous with CILRT. Type A

tests are performed for preoperational plants and

periodically for operational units. Preoperational

testing is only concerned with determining the AL

containment condition. The AL condition is that at the

completion of the test sequence. This test is performed

to ensure that the containment leak tight integrity is in

a satisfactory state prior to starting power operations.

In performing the periodic Type A test, the licensee is

required to determine both the AF and AL conditions of

the containment structure. The AF condition is that at

the time of reactor shutdown preceding the Type A test.
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This test is performed to disclose the normal state of

the containment leak tight integrity and to determine if

there is any abnormal deterioration of the containment

structure occurring.

c. Inspection Requirement 02.03a

1. Pressure tests for strength (hydrostatic or pneumatic

pressure) are required to be performed for new construction plants and for those that have undergone major

repairs which require strength welding. This test is

performed to determine whether the containment structure

complies with specified strength and design criteria of

the TS. These test results shall be within specification

prior to the initiation of leakage rate tests.

2. (a) Prior to commencing the preoperational CILRT, it is

generally recommended that Type B and C LLRTs be

performed on all appropriate penetrations to provide

an indication of how leak tight the containment

structure can be made.

(b) Any major containment modification or repair shall

be followed by either Type B or C LLRTs, as applicable, for the area affected by the modification. In

certain cases, LLRTs would not be an appropriate

retest, but rather, a Type A test (CILRT) is necessary.

3. Containment isolation system function tests shall be

performed prior to the preoperational CILRT in order to

verify that these systems operate properly and that they

do not require any repairs or modifications.

d. Inspection Requirement 02.03b

1. A general inspection of the accessible portions of the

containment structure and components is performed to

determine if there is any evidence of structural deterioration which may affect either the containment structural

integrity or leak tight integrity. If evidence of

deterioration exists, no CILRTs shall be performed until

all repairs and retests are complete.

2. The inspector shall ensure that enough specific guidance

is provided in the procedure to permit personnel to

adequately inspect the containment.

e. Inspection Requirement 02.03c

1. (a) The temperature survey of the containment structure

is performed to permit the accurate measurement of

containment temperatures and thermal variations in

order to improve the accuracy of the overall weighted

containment temperature. The survey should indicate

where the temperature readings were taken for each

subvolume, the conditions under which they were taken
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(e.g., fans operating or secured and heat loads in

the area), and establish an acceptance criteria for

the final location of the sensor in each subvolume

(e.g., placed where the temperature is within 2F of

the subvolume average).

(b) This information is essential for ensuring that the

sensor location is representative of its assigned

subvolume and furthermore, for ensuring that post

pressurization temperature/pressure stabilization has

occurred in containment to the extent necessary to

permit an accurate leakage rate measurement.

2. If the Reference-Vessel method of leakage testing is

used, the temperature pattern of containment is essential, as the reference vessels must be located in regions

which are representative of the temperature of the

subvolume each vessel represents.

3. If many thermal variations are detected, fans or other

means of air circulation may be used to equalize temperatures in these regions. In using these methods, caution

must be employed during pressurization, as the load on

these components is generally a function of air density.

In addition, the fans must be kept in the same operating

mode during the CILRT as they were during the temperature

survey.

f. Inspection Requirement 02.03d

1. All test equipment shall be calibrated over a normal

range of conditions that will be experienced during the

CILRT. Correction factors should be determined for each

sensing device prior to initiation of the CILRT.

2. All calibrations shall be traceable to NBS Standards.

3. Calibration of instruments used in the CILRT shall have

been performed no more than 6 months before the CILRT.

4. Original position checks of all test equipment shall be

performed after installation and prior to pressurization.

These checks shall have been performed within one month

of commencing the CILRT.

g. Inspection Requirement 02.04

1. The system alignments for the CILRT are performed to

reflect the conditions that would exist after a design

basis LOCA.

2. To ensure proper system alignment for the preoperational

CILRT, perform an inspector review of all recommended

lineups for systems penetrating the primary containment.

Prior to the performance of periodic CILRTs, the inspector shall review the effect and basis of all system

alignment changes from those initially prescribed in the
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preoperational test procedure. Verify that no artificial

leakage barriers exist.

3. Closure of containment isolation valves (CIVs) for the

CILRT shall be directed to be accomplished by normal

operation without any exercising (valve cycling) or

adjustments (e.g., no tightening of the valve packing

after closure by the motor).

4. Repairs of any maloperating or leaking CIVs are to be

made as necessary. The pre-repair leakage rate is to be

measured to determine the LLRT penalty factor (discussed

in section 03.01h.3 of this procedure).

5. All systems which are normally fluid and may be drained,

may have the fluid driven off by the LOCA, or will not

maintain the fluid seal for 30 days after the accident

shall be vented and drained to the extent necessary to

expose the CIV seals to the containment atmosphere during

the CILRT.

h. Inspection Requirement 02.05a

1. Any excessive leakage path detected prior to commencement

of the CILRT shall be measured through an LLRT, repaired,

and then remeasured. Excessive leakage could be defined

as that which would meet any of the following criteria:

(a) that which could potentially cause the failure of the

Appendix J criteria for combined local leakage rates.

(b) that which exceeds vendor specifications for the

leakage of boundaries or valves.

(c) and that which exceeds the licensee's commitments for

allowable leakage rates.

2. Any excessive leakage path detected during the CILRT,

including the supplemental verification test, shall

result in termination of the CILRT. The local leak rate

shall be measured before and after repair of the penetration that is leaking. The leaking penetration may be

blanked off and repaired after completion of the CILRT

(per section 03.01h.4 of this procedure). After the

corrective action is complete, the CILRT shall be

restarted from the beginning of the test.

3. All excessive leakage paths are to be measured before and

after repair so that an LLRT penalty factor can be

calculated which will permit the determination of the

containment's AF condition.

The LLRT penalty factor is the difference between the

minimum pathway leakage rates of a penetration before and

after repair. The minimum pathway leakage would be the

smaller leakage rate of in-series valves tested individually, one-half the leakage rate for in-series valves
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tested simultaneously and the combined leakage rate for

valves tested in parallel.

The LLRT penalty factor is added to the CILRT leakage

rate to determine the AF containment integrated leakage

rate.

4. If a penetration leaks excessively and cannot be repaired

prior to the CILRT, it may be blanked off. The LLRT

penalty factor is required to be determined for this

penetration in order to characterize the AF condition.

In addition, the AL integrated leakage rate must also be

adjusted to compensate for the leakage that will exist

through this penetration after its repair. This is done

by adding the post repair local leak rate of this

penetration to the CILRT results.

i. Inspection Requirement 02.05c.1

1. The pressure limits to be maintained while conducting

CILRTs are as follows:

(a) Reduced pressure CILRT Pd > P .5Pa - 1 psig.

(b) Peak pressure CILRT Pd > P Pa - 1 psig.

P is the CILRT test pressure (at any time during the test)

Pd is the containment system design pressure

Pa is the calculated peak internal containment pressure

related to the design basis accident and specified in the

TS or associated bases.

2. All LLRTs performed for component repairs in conjunction

with the CILRT are to be conducted at Pa.

j. Inspection Requirement 02.05c.3. Upon completion of pressurizing the containment, sufficient time must be permitted prior

to the leakage rate measurement so that temperature (T) and

pressure (P) can equilibrate. Containment pressure will act

as a damping harmonic function until P and T equilibrate,

hence, any measurements of P and T made for leakage rate

calculations prior to this time would yield an erroneous

leakage rate measurement due to this harmonic nature.

The criteria for P and T stabilization (equilibration) are:

1. The stabilization time period must be at least 4 hours

long.

2. The weighted average containment air temperature,

averaged over the last hour, should not deviate by more

than 0.5F/hr (0.3C/hr) from the average rate of change

of the weighted average containment air temperature

averaged over the last four hours.

[i.e., T (last 2 hrs) - T(last 4 hrs)  .5F]
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k. Inspection Requirement 02.05d. During the performance of the

leakage rate test, the licensee is required to log atmospheric

and containment pressure, temperature, dewpoint temperature,

and liquid level (e.g., suppression pool or pressurizer level)

on an hourly basis. All pertinent observations shall also be

logged.

l. Inspection Requirement 02.05e

1. The leakage rate determined from absolute method leak

rate calculations shall be determined periodically. The

test data shall be plotted against time to obtain a

statistically averaged leakage rate through a linear

least squares fit of the data.

This plotting of data is to be conducted continuously

during the test to disclose any gross variations in data

or leak rates. These variations could be indicative of

an erroneous reading, failed test instrumentation, or a

penetration failure.

m. Inspection Requirement 02.05f

1. The leakage rate test period, for any method, shall

extend to 24 hours of retained internal pressure, unless

it can be adequately demonstrated that the leakage rate

can be determined during a shorter test period.

2. The only abbreviated test period leakage rate test

currently permitted by the NRC is the BN-TOP-1 method.

The duration of a successful CILRT by this method is

based upon the magnitude and trend of the measured data

and calculated leakage rates. The leakage rate must be

fairly stable and the two sided (97.5%) Upper Confidence

Limit (as discussed in section 03.01p2 of this procedure)

for the total time analysis must be less than 0.75 La,

where La is the maximum allowable leakage rate at

pressure Pa as specified in the TS or associated bases.

In addition, at least 20 data points shall have been

taken at approximately equal intervals and the test must

last at least 6 hours.

3. If regulation and BN-TOP-1 are conflicting, then regulation shall take precedence (e.g., when using BN-TOP-1

methods, the total time AF and AL Type A test results

must meet the 0.75 La limit using the appropriate

statistical and error analysis).

n. Inspection Requirement 02.05g. The method of the supplemental

verification test is not prescribed, but the test must be

conducted over a sufficient duration to yield a change in

leakage rate from the Type A test. If the BN-TOP-1 method is

being used, this verification test period must be at least one

half the length of the Type A Test. The leakage rate shall

be determined from the slope of the linear least squares fit

of the graph of the leakage rate versus time. Enough data
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points must be taken to give accurate leakage rate results

(taking only two or three data points is always insufficient).

o. Inspection Requirement 02.07. All LLRT penalty factors are

to be calculated in accordance with section 03.01h.3 of this

procedure. Verify that the LLRT penalty factors are calculated for each penetration requiring repair or adjustment and

that these penalty factors have been summed with the CILRT

result to find the AF leakage rate.

p. Inspection Requirement 02.05i

1. For peak pressure (Pa) and reduced pressure (Pt) the

associated maximum allowable leakage rates (La/Lt) are

defined in the licensee's 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 preoperation peak pressure test, Lam should

also be less than or equal to Ld, where:

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 equations must

include the LLRT penalty factor and a value for random

instrument error when determining if the CILRT was

satisfactory.

2. 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.

3. In addition, the supplemental integrated leak rate

verification test is required to be performed to validate

the Type A test. 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 correction for instrument errors or LLRT correction

factors included unless repairs or adjustments were made

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

70307-04 REFERENCES

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

10 CFR 50, Appendix J.

Memorandum from R. J. Mattson to J. H. Sniezek, "Clarification of

Appendix J Requirements - Definition of Type A Test Failures,"

January 11, 1982.

Regulatory Guide 1.11, "Instrument Lines Penetrating Primary Reactor

Containment," March 10, 1971.

Regulatory Guide 1.68, Rev. 2, "Initial Test Program for Water-Cooled Nuclear Power Plants," August, 1978.

Regulatory Guide 1.141, "Containment Isolation Provisions," April,

1978.

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

for Nuclear Reactors."

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

Systems."

ANSI/ANS-56.8-1981, "Containment System Leakage Testing Requirements." Topical Report BN-TOP-1, Revision 1, "Testing Criteria for

Integrated Leakage Rate Testing of Primary Containment Structures

for Nuclear Power Plants," Bechtel Corporation.

END