ML20084P635

Proposed Tech Specs Improving Tendon Surveillance Program

ML20084P635
Person / Time
Site:	Point Beach
Issue date:	05/02/1984
From:	WISCONSIN ELECTRIC POWER CO.
To:
Shared Package
ML20084P629	List: ML20084P626 ML20084P635
References
TAC-54989, TAC-54990, NUDOCS 8405180292
Download: ML20084P635 (6)

Text

__ .

4 VI. CONTAINMENT MODIFICATIONS Any major modification or replacement of components of the containment performed after the initial preoperational Icakage rate test shall be followed by either an integrated leakage rate test, or a local leak detection test and shall meet the acceptance criteria of I.B and II.B. respectively.

Modifications or replacements performed directly prior to the conduct of  :

an integrated leakage rate test shall not require a separate test.

VII. TENDON SURVEILLANCE d

A. Object In order to insure containment structural integrity, randomly selected tendons shall be periodically inspected for symptoms of material deterioration or lift-off force reduction. The randomly selected tendons consist of five hoop tendons, three vertical tendons located approximately 120' apart, and three dome tendons, I one from each of the three dome tendon groups.

B. Frequency Tendon surveillance shall be conducted at five-year intervals in accordance with the following schedule:*

Surveillance Unit Year Required 1 1984 Physical 2 1984 Visual 1 1989 Visual 2 1989 Physical

• Subsequent five-year interval inspections repeat this pattern.

i o

r BA0502 5fDO 05AOg P

15.4.4-8 w

k C. Inspections Tendon surveillance in accordance with 15.4.4.VII.B shall consist of either a visual or physical inspection.

(1) Visual Inspection

a. Tendon anchorage assembly hardware of the randomly selected tendons shall be visually examined to the extent practicable without dismantling load bearing components of the anchorage. The immediate concrete area shall be checked visually for indications of abnormal material behavior.

(2) Physical Inspection

a. Tendons which are physically inspected shall first be visually inspected in accordance with C.(1).

b. All tendons which are physically inspected shall be subjected to a liftoff test to monitor their prestress.

(1) If the prestressing force of a selected tendon in a group lies above the predicted lower limit, the tendon is considered to be acceptable.

(ii) If the prestressing force of a selected tendon lies between the predicted lower limit and 90%

of the predicted lower limit, two tendons, one on each side of the test tendon, shall be checked for their prestressing forces. If the prestressing forces for these tendons are above the predicted Icwer limit for the tendons, all three tendons shall be restored to the required level of integrity. A single deficiency shall be considered unique and acceptable. If the prestressing force of either of the adjacent tendons falls below the predicted lower limit of the tendon, the condition shall be considered an abnormal condition of the containment structure.

15.4.4.-9

(iii)If the prestressing force of the selected test tendon falls below 90% of the predicted lower limit, the tendon shall be completely detensioned and a determination shall be made ,

as to the cause of the condition. Such a condition shall be considered an abnormal l conditica of the containment structure. ,

c. One randomly selected tendon from each group of tendons shall be subjected to complete detensioning in order to identify broken or damaged wires. During the retensioning of the detensioned tendon, simultaneous measurements of elongation and jacking force shall be made at a minimum of two levels of force between the required seating force and zero. During the detensioning and retensioning of the tendons tested, if the elongation corresponding to a specific load differs by more than 5%

from that recorded during installation of the tendons, an investigation shall be made to ensure that such discrepancies are not related to wire failures or slippage of wires in anchorages.

d. A tendon wire shall be removed from the one tendon from each group which has been completely detensioned.

The wire shall be inspected over its entire length to determine if evidence of corrosion or other deleterious effects are present. Tensile tests shall be made on three samples cut from each removed wire.

The samples will be cut from the midsection and each end of the removed wire. Failure of the material to demon-strate the required tensile strength shall be considered an abnormal condition of the containment structure.

l 15.4.4-10

s. *

,e. The sheathing filler will be sampled and inspected on each physically inspected tendon. Conditions such as the presence of significant voids within the grease filler material, the presence of free water, or chemical or physical properties outside the tolerance in the material specifications shall be considered an abnormal condition of the containment structure.

D. Reports A final report documenting the results of each tendon ,

surveillance will be prepared and maintained as a permanent plant record.

Abnormal conditiens observed during' testing will be evaluated to determine the effect of such conditions on containment struc-tural integrity. This evaluation should be completed within 30 days of the identification of the condition. Any condition which is de-termined in this evaluation to have a significant adverse effect on containment structural integrity will be considered an abnormal de-gradation of the containment structure. ,

I Any abnormal degradation of the containment structure identified during the engineering evaluation of abnormal conditions shall be re-ported to the U. S. Nuclear Regulatory Commission, Office of Inspec-tion and Enforcement, Region III within thirty days of that determina-tion. Other conditions th'at indicate possible effects on the integ-rity of two or more tendons shall be reportable in the same manner.

Such reports shall include a description of the tendon condition, the condition of the concrete (especially at tendon anchorages), the in-spection procedure and the corractive action taken.

. 15.4.4-10a

containment. A residual Heat Removal System leakage of 2 gal /hr. will limit off-site exposures due to leakaFe to insignificant levels relative to those calculated for leakage directly from the containment in the Design Basis Accident. The dose calculated as a result of this leakage is 7.7 mr for a 2 hour2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> exposure at the site boundary. (5)

Periodic visual and physical inspection of the containment tendons is the method to be used to determine loss of load-carrying. capability because of wire breakage or deterioration. The tendon surveillance program specified in 15.4.4.VII is based on the recommendation of "

Regulatory Guide 1.35 Rev. 3. Containment tendon structural integrity was demonstrated for both units at the end of one, three and eight years ,

following the initial containment structural integrity test.

The pre-stress lift-off test provides a direct measure of the load-carrying capability of the tendon. A deterioration of the corrosion preventive properties of the sheathing filler will be indicated by a change in the physical appearance of the filler. If the surveillance  :

program indicates, by extensive wirc breakage, tendon stress-strain relations, or other abnormal conditions, that the pre-stressing ten-dons are not behaving as expected; the abnormal conditions will be ,

subjected to an engineering analysie and evaluation in accordance with Specification 15.4.4.VII.D to determine whether the condition could result in a significant adverse impact on the containment struc-  :

r tural integrity. The specified acceptance criteria are such as to alert attention to the situation well before the tendon load-carrying capability would deteriorate to.a point that failure during a design basis accident might be possible. Thus, the cause of the incipient deterioration could be evaluated and corrective action studied with-I out need to shut down the reactor. If the engineering evaluation determines that the abnormal condition could result in a significant adverse impact on the containment structural integrity, an abnormal degradation situation will be declared and a report submitted to the l

NRC in accordance with the specifications.

15.4.4-15 i-----, ,,, , -- _m , , - - .

The purpose of the leakage tests of the isolation valves in the containment purge supply and exhaust lines is to identify excessive degradation of the resilient seals for these valves. With the excep-tion of the test frequency and acceptance criteria, leakage tests of the containment purge supply and exhaust valves shall be conducted, in accordance with 15.4.4.III.

E r

F References (1) FSAR Section 5.1.2.3 (2) FSAR Section 5.1.2 (3) FSAR Section 14.3.5 i

(4) FSAR Section 14.3.4 (5) FSAR Section 6.2.3 15.4.4-16 r

s

. - , _ _ _ , .,