Issue Date: 10/03/85 - 1 - 70313

NRC INSPECTION MANUAL DI

INSPECTION PROCEDURE 70313

CONTAINMENT INTEGRATED LEAK RATE TEST SURVEILLANCE

PROGRAM APPLICABILITY: 2513, 2515 (BASIC)

70313-01 INSPECTION OBJECTIVE

01.01 Ascertain through inspector observation, records review

and independent calculations whether the containment integrated leak

rate test (CILRT) is being properly conducted.

01.02 Independently verify the acceptability of test results

through on-the-spot analysis and further indepth, independent

analysis.

70313-02 INSPECTION REQUIREMENTS

02.01 Ensure that the following prerequisites are met before

commencing containment pressurization of all CILRTs (Type A tests):

[See section 03.02a for explanations for the preoperational and

operational Type A tests, including as found (AF) and as left (AL)

conditions.]

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

major repairs the following tests shall have been 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 is satisfactorily

complete.

c. The containment area survey for temperature differentials and

humidity is or has been performed for the conditions which

exist throughout the CILRT (e.g., fans operating or secured,
70313 - 2 - Issue Date: 10/03/85

no heat loads (pre-op), or heat loads (decay heat) and sensing

devices are in place in locations representative of their

assigned subvolume.

d. All test instruments are within calibration at the initiation

of the CILRT.
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e. Each applicable plant system is aligned in accordance with one

of the following criteria:

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

condition shall be operable and in their normal modes.

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

of coolant accident (LOCA) shall be vented to containment.

3. Any system open to containment under post-LOCA conditions

shall be opened or vented to containment prior to and

during the test.

4. Any system that would be normally operating under

post-LOCA conditions is not required to be vented during

the test.

5. Any system or component sensitive to damage from high

pressures or pressure differentials shall be isolated or

removed from containment.

6. All other systems containing fluids that are, or may

become, pressurized from external pressure sources shall

be depressurized and isolated from containment.

f. Vacuum-release devices are verified to operate within 10% of

their design pressures for internal and external loading to

ensure containment protection from under pressure.

g. 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.

h. The containment structure is properly closed out according to

licensee procedure.

i. The current licensee procedure that describes the method of

decompression for personnel exposed to pressurization is on

hand, if personnel entry into the pressurized containment is

allowed.

j. The most recent, approved version of the licensee's procedure

for CILRT is available and in use by all test crew members.

02.02 Verify that the licensee properly responds to all

excessive leakage paths detected before or during the CILRT.

02.03 Ensure that the reduced pressure test and the peak

pressure test are performed sequentially during the preoperational

CILRT (if performing the reduced pressure test).

02.04 Monitor the containment pressurization and ensure the

following:
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a. Personnel are aware of the minimum and maximum pressurization

requirements for CILRTs.

b. The pressurization source, upon reaching test pressure, is

isolated from containment and vented.

c. Pressure-temperature stabilization is observed prior to

commencing the leakage-rate measurement.

02.05 Ensure that during the leakage-rate measurement the

licensee is observing all CILRT requirements by verifying the

following:

a. All required plant parameters are being recorded, at a

minimum, on an hourly basis.

b. The test log is being properly maintained with all pertinent

observations being logged and with personnel responsible for

the correctness for the observations so attesting in the log.

c. The CILRT meets the minimum time requirement for test

duration.

d. Leakage-rate computations for the absolute method are

performed periodically. The leak rate test data shall be

plotted against time to calculate a statistically averaged

leakage rate.

e. The supplemental verification test complies with the change

in leakage rate and test period requirements.

02.06 Determine the CILRT leakage rates obtained through use of

either the CILRT program ("A Computer Program For Containment

Integrated Leak Rate Testing") or other NRC accepted methods of

analysis and compare with the licensee's initial results.

02.07 Verify that the proper LLRT correction factors are

included in the CILRT results.

02.08 Determine if the CILRT was satisfactory for both the AF

and the AL containment conditions.

02.09 If either the AF or AL condition is determined to be a

failure, verify that the licensee is aware of the ensuing consequences and requirements.

70313-03 INSPECTION GUIDANCE

General Guidance. The proper witnessing and evaluation of a CILRT

requires an indepth understanding of containment system testing, as

well as a good understanding of the plant specific containment

systems and components. To achieve this balance necessitates the

utilization of both regional and resident NRC inspectors in

observing the performance of the CILRT. Generally, the regional

inspector shall perform the majority of the inspection and should

only request resident inspector assistance for the performance or
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certain prerequisite requirements including a check of system

alignments.

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 70313-04 of this procedure.

a. Inspection Requirement 02.01

1. 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 as left

(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 proceeding the Type A test.

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.

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

f-sections 4.1 and 4.2)

2. All test prerequisites shall be verified as being met

through observing the initialing (signing off) of all

requirements for the CILRT in its associated procedural

record. The initials shall be those of an authorized

person attesting to the completion of the particular

requirement.

b. Inspection Requirement 02.01a

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 Technical Specifications (TS). These test results

shall be within specification prior to the initiation of

leakage-rate tests.

(refs: f-section 4.3, h-section 3.2)

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
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an indication of how leak-tight the containment can

be made.

(refs: f-section 4.1, h-section 3.2)

(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, LLRT's would not be an appropriate

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

(ref: b-section IV.A.)

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.

(ref: h-section 3.2.1.2)

c. Inspection Requirement 02.01b

1. A general inspection of the accessible portions of the

containment structure and components shall be 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.

(ref: b-section V.A.)

2. To verify that this inspection is satisfactorily complete, a review should be performed of the containment

inspection procedure and its results. Ensure that enough

specific guidance is provided in the procedure to permit

personnel to adequately inspect the containment. The

procedure and results should be compared with the

licensee's TS and Final Safety Analysis Report (FSAR).

d. Inspection Requirement 02.01c

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

is performed to permit the accurate measure 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

(e.g., fans operating or secured and heat loads in

the area) and establish an acceptance criteria for

the final sensor locations in each subvolume (e.g.,

the sensor may be placed where the temperature is

within 2F of the subvolume average).
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(b) This information is essential 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 is representing.

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. For this reason, it is recommended that licensees perform two surveys, one with fans secured and one

with fans operating, to cover either possibility.

(refs: f-sections 4.6, 7.4, h-section 5.5.1)

e. Inspection Requirement 02.01d

1. All test equipment shall have been calibrated over the

normal range of conditions experienced during the CILRT.

Correction factors should be determined for each sensing

device prior to initiation of the CILRT.

(refs: f-section 6.2 and 6.3, h-section 4.2.3)

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.

An in-site check of all test equipment shall be performed

after installation and prior to pressurization. These

checks shall be within one month of initiation of the

CILRT.

(ref: h-section 4.2.2)

4. An inspector check of the methods used, the raw data, and

the results of the calibrations and in-situ checks of at

least 20% of the instrumentation used for the CILRT

should be performed to verify proper equipment calibration.

f. Inspection Requirement 02.01e

1. The system alignments for the CILRT are performed to

reflect the conditions that would exist after a design

basis LOCA.
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2. To ensure proper system alignment, perform an inspector

walkdown on 100% of the containment penetrations for

external systems normally pressurized to containment and

on 10% of the systems vented to containment during the

CILRT. Determine if the valve alignments have been

conducted in accordance with the procedure and verify

that no artificial leakage barriers have been erected.

In addition, an analysis of how systems are aligned

should be performed to determine if the licensee is

properly employing the requirements.

3. To verify proper vent paths, the inspector should ensure

that vent valve orifice plugs (valve caps) are removed,

as well as, the vent valve being open.

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

CILRT shall 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).

(ref: b-section III.A.1.(b))

5. Repairs of any maloperating or leaking CIVs shall be made

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

measured to determine the LLRT correction factor (discussed in section 03.01i3 of this procedure).

(ref: b-section III.A.1.(b))

6. All systems which are normally fluid filled 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. However, systems that are

required for proper conduct of the CILRT or to maintain

the plant in a safe condition need not be vented or

drained. Systems that are not vented and drained during

the CILRT and which could become exposed to the containment atmosphere during a LOCA must undergo LLRTs with

their leakage rate determined using minimum pathway

leakage added to the CILRT correction factor (discussed

in section 03.01i3 of this procedure).

(refs: b-section III.A.1.(d), III.B.3.(b), and h-section

3.2.1.5)

7. Due to the detailed plant specific knowledge necessary to

rapidly walkdown system alignments, it is recommended

that the resident inspector shall assist in this inspection by exclusively performing these walkdowns. This

would enable the regional inspectors to concentrate more

on generic CILRT requirements.

g. Inspection Requirement 02.01i. Exposure of personnel to

pressurized air and return to normal atmospheric pressures
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during the course of containment structure leakage-rate

testing shall be governed by approved decompression procedures

involving a controlled depressurizing rate and waiting periods

at intermediate pressures. For exposures of no longer than

200 min. at pressures not greater than 14.3 psig., no

intermediate holding periods or decompression stops are

required provided the time period of pressure reduction in the

air lock to atmospheric level is not less than 30 sec. For

exposure to pressurization in excess of 14.3 psig, and for

exposure periods including repetitive exposure within 12 hr.

the practices should conform to those stipulated in Section

1.5, Diving Tables of the U.S. Navy Diving Manual, NAVSHIPS

250-538, January 1959. Local and State regulations should

also be consulted.

(ref: f-section 7.5)

h. Inspection Requirement 02.02

1. Any excessive leakage path detected prior to commencement

of the CILRT shall be measured through an LLRT, repaired

and then remeasured. Excessive leakage is that which

would meet any of the following criteria:

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

Appendix J requirements for combined local leakage

rates.

(b) that which exceeds licensee commitments for allowable

leakage rates.

(c) and that which exceeds vendor specifications for that

boundary or valve.

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 03.02i4 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 correction factor can be

calculated which will permit the determination of the

containment's AF condition.

The LLRT correction 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

tested simultaneously and the combined leakage rate for

valves tested in parallel.
70313 - 10 - Issue Date: 10/03/85

The LLRT correction 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.

(refs: b-section III.A.1, f-section 4.2, and h-section

3.2)

i. Inspection Requirement 02.04a

1. The pressure limits to be maintained while conducting

CILRTs are as follow:

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

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

where:

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.

(refs: b-section III.A.4 and h-section 3.2.2)

2. All LLRTs performed for component repairs in conjunction

with the CILRT are to be conducted at Pa.

(refs: b-section III.B.2, C.2. and h-section 3.3.2)

j. Inspection Requirement 02.04c. 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. Contain pressure will act as

a damping harmonic function until P and T equilibrate, hence,

and 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.
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2. After reaching test pressure, the weighted average

containment air temperature, averaged over the last hour,

shall not deviate by more than 0.5F/hr from the average

rate of change of the weighted average containment air

temperature averaged over the last four hours. Or,

*T/hour (last hr) - T/hour (last 4 hrs)* .5F/hour

(refs: b-section III.A.1.c and h-section 5.3.1.3)

k. Inspection Requirement 02.05a. During the performance of the

leakage rate test, the licensee is required to record

atmospheric and containment pressure, temperature, dewpoint

temperature and liquid level (e.g., suppression pool or

pressurizer level).

l. Inspection Requirement 02.05c

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

given in reference i. The duration for a successful

CILRT by the BN-TOP-1 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 (per section

03.02p2 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 associate 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.

(refs: f-section 7.6 and i-section 2.3)

3. If regulation and BN-TOP-1 are conflicting, 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).

m. Inspection Requirement 02.05d

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 test 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
70313 - 12 - Issue Date: 10/03/85

an erroneous reading, failed test instrumentation or a

penetration failure.

(ref: f-section 7.9)

2. The inspector should independently verify and plot the

leakage rates. The technique for independent calculations is located in ref. f section 7.9.

n. Inspection Requirement 02.05e. 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 BN-TOP-1 is being used,

the verification test must be at least one half the length of

the Type A test conducted. 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 points

must be taken to give accurate leakage rate results (taking

only two or three data points is always insufficient).

(ref: b-section III.A.3.b)

o. Inspection Requirement 02.07. All LLRT penalty factors are

to be calculated in accordance with step 03.01i3 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 02.08

1. 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:

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.

(ref: b-section III.A)

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
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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: b-section III.A.3(c), h-section 5.74,l)

3. In addition, the supplemental integrated leak rate

verification test is required to be performed to validate

the Type A test 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 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.

(ref: b-section III.A.3.b)

70313-04 REFERENCES

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

b. 10 CFR 50, Appendix J.

c. Memorandum for R. J. Mattson to J. H. Sniezek, "Clarification

of Appendix J Requirements - Definition of Type A Test

Failures," January 11, 1982.

d. Regulatory Guide 1.11, "Instrument Lines Penetrating Primary

Reactor Containment," March 10, 1971.

e. Regulatory Guide 1.141, "Containment Isolation Provisions."

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

Structures for Nuclear Reactors."

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

Fluid Systems."

h. ANSI/ANS-56.8-1981, "Containment System Leakage Testing

Requirements."
70313 - 14 - Issue Date: 10/03/85

i. 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