ML20209D025

Proposed Tech Specs Re RCS Surveillance Requirements

ML20209D025
Person / Time
Site:	Trojan File:Portland General Electric icon.png
Issue date:	04/20/1987
From:	PORTLAND GENERAL ELECTRIC CO.
To:
Shared Package
ML20209D009	List: ML20209D003 ML20209D025
References
TAC-64756, NUDOCS 8704290152
Download: ML20209D025 (6)

Text

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LCA 152 Attachment l' Page 1 of 6-REACTOR COOLANT SYSTEM 4

SURVEILLANCE' REQUIREMENTS (Continued)

1. All nonplugged tubes that previously had detectable wall penetrations (>20%).

2. Tubes in those areas where experience has indicated potential problems.

i 3. A tube inspection (pursuant to Specification 4.4.5.4.a.8) shall be performed on each selected tube. .If'any' selected tube does.not permit the passage of the eddy current probe '

for a tube inspection, this shall be recorded and an adjacent tube shall be selected and subjected to a tube inspection.

c. In addition to the 3% sample, all tubes with defects below the '

F* distance which have not been plugged shall be' inspected in the tube sheet region.

d. The tubes selected as the second and third samples (if required l by Table 4.4-2) during each inservice inspection may be subjected to a partial tube inspection provided:

1. The tubes selected for these samples include the tubes i from those areas of the tube sheet array where tubes with l- imperfections were previously found.

2. The inspections include those portions of the tubes where imperfections were previously found.

!- The results of each sample inspection shall be classified into one of the following three categories:

Category Inspection Results i

C-1 Less than 5% of the total tubes inspected '

are degraded tubes and none of the inspected i

tubes are defective.

C-2 One or more tubes, but not more than 1% of the total tubes inspected are defective, or between 5% and 10% of the total tubes inspected are degraded tubes.

I C-3 More than 10% of the total tubes inspected i are degraded tubes or more than 1% of the

, inspected tubes are defective.

I Note: In all inspections, previously degraded tubes must 4

exhibit significant (>10%) further wall penetrations l to be included in the above percentage calculations.

TROJAN-UNIT 1 3/4 4-7 Amendment No. 81 1-0704290152 B70420 4 PDR ADOCK 05000344 i P

__ . . _ . _ _ _ _ _ _ _ _ . PDR_

LCA 152 Attachment 1 l

- Page 2 of 6 I REACTOR COOLANT SYSTEM SURVEILLANCE REQUIREMENTS (Continued) 4.4.5.3 Inspection Frecuencies - The above required inservice inspections of steam generator tubes shall be performed at the following frequencies:

a. The first inservice inspection shall be performed after 6 Effective Full Power Months but within 24 calendar months of initial criticality. Subsequent inservice inspections shall be performed at intervals of not less than 12 nor more than 24 calendar months af ter the previous inspection. If two consecu-tive inspections following service under AVT conditions, not  !

including the preservice inspection, result in all inspection results falling into the C-1 category or if two consecutive inspections demonstrate that previously observed degradation has not continued and no additional degradation has occurred, the inspection interval may be extended to a maximum of once per 40 months.

b. If the results of the inservice inspection of a steam gen-erator conducted in accordance with Table 4.4-2 at 40 month intervals fall in Category C-3, the inspection frequency shall be increased to at least once per 20 months. The increase in inspection frequency shall apply until the subsequent inspections satisfy the criteria of Specifica-tion 4.4.5.3.a; the interval may then be extended to a maximum of once per 40 months.

c. Additional, unscheduled inservice inspections shall be performed on each steam generator in accordance with the first sample inspection specified in Table 4.4-2 during the shutdown subsequent to any of the following conditions:

1. Primary-to-secondary tube leaks (not including leaks t originating from tube-to-tube sheet welds) in excess of the limits of Specification 3.4.6.2.

2. A seismic occurrence greater than the Operating Basis Earthquake.

3. A loss-of-coolant accident requiring actuation of the engineered safeguards.

4. A main steam line or feedwater line break.

TROJAN-UNIT 1 3/4 4-8 Amendment No. BT

LCA 152 Attachment 1 Page 3 of 6 REACTOR COOLANT SYSTEM SURVEILLANCE REQUIREMENTS (Continued) 4.4.5.4 Acceptance Criteria

a. As used in the Specification:

1. Imperfection means an exception to the dimensions, finish or contour of a tube from that required by fabrication drawings or specifications. Eddy-current testing indica-tions below 20% of the nominal tube wall thickness, if detectable, may be considered as imperfections.

2. Degradation means a service-induced cracking, wastage, wear or general corrosion occurring on either inside or outside of a tube.

3. Degraded Tube means a tube containing imperfections >20%

of the nominal wall thickness caused by degradation.

4.  % Degradation means the percentage of the tube wall thickness af fected or removed by degradation.

5. Defect means an imperfection of such severity that it exceeds the plugging limit. A tube containing a defect is defective.

6. Pluqqing Limit means the imperfection depth at or beyond which the tube shall be removed from service because it may become unserviceable prior to the next inspection and is equal to (40)% of the nominal tube wall thickness. This definition does not apply to the area of the tube sheet region below the F* distance, provided the tube has no indications of cracking within the F* distance.

7. Unserviceable describes the condition of a tube if it leaks or contains a defect large enough to affect its structural integrity in the event of an Operating Basis Earthquake, a loss-of-coolant accident, or a steam.line or feedwater line break as specified in 4.4.5.3.c, above.

8. Tube Inspection means an inspection of the steam generator tube from the point of entry (hot leg side) completely around the U-bend to the top support of the cold leg.

TROJAN-UNIT 1 3/4 4-9 Amendment No. 67 I

LCA 152

. Attachment 1 Page 4 of 6 REACTOR COOLANT SYSTEM SURVEILLANCE REQUIREMENTS (Continued)

9. Preservice Inspection means an inspection of the full length of each tube in each steam generator performed by eddy current techniques prior to service establish a baseline condition of the tubing. This inspection shall be performed af ter the field hydrostatic test and prior to initial POWER OPERATION using the equipment and techniques expected to be used during subsequent inservice inspections.

10. Tube Roll Expansion is that portion of a tube which has been increased in diameter by a rolling process such that no crevice exists between the outside diameter of the tube and the tube sheet.

11. F* Distance is the minimum length of the roll expanded portion of the tube which cannot contain any indications of cracking in order to ensure the tube does not pull out of the tube sheet. The F* distance is 1.4 inches and is measured from the top of the roll expansion of the tube down toward the bottom of the tube sheet.

b. The steam generator shall be determined OPERABLE af ter completing the corresponding actions (plug all tubes exceeding the plugging limit) required by Table 4.4-2.

4.4.5.5 Reports

a. Following each inservice inspection of steam generator tubes, the number of tubes plugged in each steam generator shall be re.ccrted to the Commission within 15 days.

b. The complete results of the steam generator tube inservice inspection shall be reported on an annual basis for the period in which the inspection was completed. This report shall include:

1. Number and extent of tubes inspected. l

2. Location and percent of wall-thickness penetration for i each indication of an imperfection.

3. Identification of tubes plugged.

c. Results of steam generator tube inspections which fall into Category C-3 shall be reviewed for reportability pursuant to Specification 6.6.1. If the results are deemed reportable, such report must be submitted to the Commission prior to the resumption of plant operation.

TROJAN-UNIT 1 3/4 4-9a Amendment No. 67

LCA 152

. Attachment 1 Page 5 of 6 REACTOR COOLANT SYSTEM SURVEILLANCE REQUIREMENTS (Continued)

d. The results of inspections of all tubes which have defects below 4

the F* distance, but which were not plugged, shall be reported to the Commission following the inspection and prior to the restart of the unit. The report shall include:

1. Identification of the applicable tubes, and

2. Location and size of the degradation.

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TROJAN-UNIT 1 3/4 4-9b knendment No. 97

LCA 152 Attachment 1 Page 6 of 6 REACTOR COOLANT SYSTEM BASES 3/4.4.5 STEAM GENERATORS CONTINUED system and the secondary coolant system (primary-to-secondary leakage =

500 gallons per day per steam generator). Cracks having a primary-to-secondary leakage less than this limit during operation will have an adequate margin of safety to withstand the loads imposed during normal operation and by postulated accidents. Operating plants have demonstrated that primary-to-secondary leakage of 500 gallons per day per steam generator can readily be detected by radiation monitors of steam generator blowdown. Leakage in excess of this limit will require plant shutdown and an unscheduled inspection, during which the leaking tubes will be located and plugged.

Wastage-type defects are unlikely with the all volatile treatment (AVT) of secondary coolant. However, even if a defect of similar type should develop in service, it will be found during scheduled inservice steam generator tube examinations. Plugging will be required of all tubes with imperfections exceeding the plugging limit which, by the definition of Specification 4.4.5.4.a is 40% of the tube nominal wall thickness.

Tubes with defects below the F* distance do not have to be plugged or repaired as long as there are no indications of cracking in the F* dis-tance. The F* distance is 1.4 inches and includes a safety factor of 3 and a 0.5-inch eddy current measurement uncertainty. Steam generator tube inspections of operating plants have demonstrated the capability to reliably detect wastage-type degradation that has penetrated 20% of the [

original tube wall thickness.

Whenever the results of any steam generator tubing inservice inspection fall into Category C-3, these results will be promptly reported to the Commission pursuant to Specification 6.9.1 prior to resumption of p'iant operation. Such cases will be considered by the Commission on a case-by-case basis and may result in a requirement for analysis, laboratory examinations, tests, additional eddy-current inspection, and revision of the Technical Specifications, if necessary.

3/4.4.6 REACTOR COOLANT SYSTEM LEAKAGE l l

3/4.4.6.1 LEAKAGE DETECTION SYSTEMS The RCS leakage detection systems required by this specification are provided to monitor and detect leakage from the Reactor Coolant Pressure Boundary. These detection systems are consistent with the recommendations of Regulatory Guide 1.45, " Reactor Coolant Pressure Boundary Leakage Detection Systems", May 1973.

TROJAN-UNIT 1 B 3/4 4-2a Amendment No. 67