ML20049J977

Proposed Revision to Tech Spec 3.6.1.6 Re Containment Structural Integrity.Related Info,Including Detailed Discussion Encl

ML20049J977
Person / Time
Site:	Summer
Issue date:	03/22/1982
From:	SOUTH CAROLINA ELECTRIC & GAS CO.
To:
Shared Package
ML20049J976	List: ML20049J975 ML20049J977
References
NUDOCS 8203290283
Download: ML20049J977 (24)

Text

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CONTAINMENT SYSTEMS CONTAIN)ENT STRUCTURAL INTEGRITY LIMITING CONDITIONS FOR OPERATION 3.6.1.6 The structural integrity of the containment shall be maintained at c level consistent with the acceptance criteria in; Specification 4.6.1.6.

APPLICABILITY: MODES 1, 2, 3 and 4.

ACIION:

a. With the structural integrity of the containment not conforming to the requirements of Specification 4.6.1.6.1.b, perform an engineer-ing evaluation of the containment to demonstrate the acceptability of containment tendons within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />; otherwise, be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />,

b. With the structural integrity of the containment otherwise not conferming to the requirements of Specification 4.6.1.6, in lieu of any other report required by Specification 6.9.1, prepare and submit a Special Report to the Comnission pursuant to Specifica-tion 6.9.2 within 30 days describing the tendon condition, the condition of the concrete (especially at tendon anchorages), the inspection procedures, the tolerances on cracking, and the corrective actions taken.

SURVEILLANCE REQUIREMENTS 4.6.1.6.1 The structural integrity of the containment tendens shall be demon-strated at the end of one, three and five years following the initial containment structural integrity test and at five year intervals thereafter. The structural integrity of the tendons shall be deaonstrated by:

a. Determining that for a representative sample

• of at least 15 tendons (4 dome, 5 vertical and 6 hoop) each has a lift off force greater than or equal to its Lower Limit indicated in Table 4.6-la. If the lift off force of a selected tendon in a group lies between the prescribed Lower Limit and 90% of the Lower Limit, one tendon on each side of this tendon shall be checked for its lif t off force. If the lift off forces of the adjacent tendons are greater than or equal to their Lower Limits in Table 4.6-lb, the single deficiency shall be considered

• For each inspection, the tendons shall be selected on a random but representa-tive basis so that the sample group will change somewhat for each inspection; however, to develop a history of tendon performance and to correlate the observed data, one tendon from each group (dome, vertical, and hoop) may be kept unchanged after the initial selection.

3/4 6-8 8203290283 820322 DR ADOCK 05000395 PDR

CONTAINMENT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued) unique and acceptable. For tendon (s) not conforming to these require-ments, a determination shall be made as to the cause of the occurrence and the tendon (s) shall be restored to the required level of integrity.

b. Determining that the average of the Normalized Lift Off Forces for each tendon group (vertical, dome and hoop) is greater than or equal to 1195 kips for vertical tendons, 1115 kips for dome tendons, and 1181 kips for hoop tendons. The Normalized Lift Off Force for a tendon is obtained by adding the Normalizing Factor appearing in Table 4.6-2 to the lift off force. Failure to comply with this requirement may be evidence of abnormal degradation of the containment structure,

c. Detensioning one tendon in each group (dome, vertical and hoop) from the representative sample. One wire shall be removed from each detensioned tendon and examined to determine:

1. That over the entire length of the tendon wire, the wire has not undergone corrosion, cracks or damage to the extent that an abnormal condition is indicated.

2. A minimum tensile strength value of 240,000 psi (guaranteed ultimate strength of the tendon material) for at least three wire samples (one from each end and one at mid-length) cut from each removed wire.

Each tendon shall be retensioned to within 3% of its lift off force measured prior to detensioning.

d. Determining for each tendon in the above representative tendon sample, that an analysis of a sample of the sheathing filler grease is within the following limits:

1. Grease Voids j[ 5% of net duct volume

2. Chlorides < 10 PPM

3. Sulphides ji 10 PPM

4. Nitrates ji 10 PPM

5. Water Content j[ 10% by weight 4.6.1.6.2 At the same inspection frequency as the tendons, the structural integrity of the end anchorages of all tendons inspected pursuant to Specification 4.6.1.6.1 and the adjacent concrete surfaces shall be determined by a visual inspection and verifying that no abnormal material or structural behavior is evident.

3/46-9

CONTAINMENT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued) 4.6.1.6.3 At the same inspection f recuency as the Type A containment leakage rate test, the structural integrity of the exposed accessible interior and exterior surfaces of the containment shall oe determined prior to each Type A containment leakage rate test (Specification 4.6.1.2) by a visual inspection of these surfaces and verifying that no abnormal material or structural behavior is evident.

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TABLE 4.6-la TENDON FORCE ACCEPTANCE CRITERIA SURVEILLANCE TENDONS

• INSPECTION PERIOD 1 1 2 3 Tendon Lower Limit (kips) Tendon Lower Limit (kips) Tendon Lower Limit (kips)

D-104 1251 D-125 1208 D-108 1260 D-129 1222 D-219 1233 D-121 1202 0-219 124? D-228 1250 D-219 1228 D-328 1262 D-324 1249 D-312 1245 V-23 1303 V-23 1294 V-23 1288 V-46 1282 V-30 1262 V-37 1275 V-67 1307 V-53 1289 V-60 1269 i V-92 1273 V-76 1288 V-83 1287 l V-115 1296 V-99 1280 V-106 1273 3AC 1295 3AC 1287 3AC 1280 8BA 1250 13BA 1258 8CB 1230 13CB 1260 18CB 1240 18BA 1230 28CB 1242 28BA 1239 28AC 1238 38AC 1232 33CB 1257 33BA 1252 38BA 1230 36AC 1251 38CB 1211

• If the inspection performed at one, three and five years indicate no abnormal degradation of the post-tensioning system, the number of tendons selected for subsequent surveillances may be reduced to a representative sample of at least 9 tendons (3 dome, 3 vertical and 3 hoop).

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TABLE 4.6-lb TENDON FORCE ACCEPTANCE CRITERIA ADJACENT TENDONS INSPECTION PERIOD 1 2 3 Tendon Lower Limit (kips) Tendon Lower Limit (kips) Tendon Lower Limit (kips)

D-103 1225 D-124 1259 D-107 1217 D-105 1229 D-126 1238 D-109 1198 D-128 1271 D-218 1260 D-120 1256 D-130 1242 D-220 1262 D-122 1237 D-218 1272 D-227 1247 D-218 1253 D-220 1273 D-229 1211 D-220 1257 D-327 1222 D-323 1230 D-311 1240 D-329 1214 D-325 1204 D-313 1212 V-22 1281 V-22 1275 V-22 1270 V-24 1292 V-24 1284 V-24 1280 V-45 1285 V-29 1278 V-36 1262 V-47 1300 V-31 1300 V-38 1269 V-66 1283 V-52 1288 V-59 1282 V-68 1284 V-54 1273 V-61 1282 V-91 1286 V-75 1280 V-82 1273 V-93 1302 V-77 1289 V-84 1278 V-114 1289 V-98 1256 V-105 1271 V-1 1290 V-100 1273 V-107 1281 2AC 1257 2AC 1248 2AC 1242 4AC 1239 4AC 1230 4AC 1223 7BA 1296 12BA y 1243 7CB 1272 9BA 1267 14BA ' 1239 9CB 1257 12CB 1260 17CB 1249 17BA 1233 14CB 1250 19CB 1262 19BA 1262 27CB 1254 27BA 1264 27AC 1268 29CB 1257 29BA 1248 29AC 1231 37AC 1260 32CB 1237 32BA 1230 39AC 1272 , 34CB 1211 343A 1229 37BA 1273 35AC 1270 37CB 1252 39BA 1250 37AC 1250 39CB 1262 c I I 3/4 6-10b

. . ~ . - - - . . .. ~- .

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t TABLE 4.6-2 1

NORMALIZING FACTORS (N.F.)

1

+

INSPECTION PERIOD 1 2 3 Tendon N.F. (kips) Tendon N.F. (kips) Tendon N.F. (kips)

! D-104 -24 D-125 36' D-108 -42 D-129 33 D-219- 10~ D-121 40 D-219 10 D-228 -28 D-219 10 D-328. -21 ~D-324 -12 D-312 -20 V-23 -15 V-23 -15 V-23 -15 V-46 V-30 V-37 -5

11. 31 V-67 -21 V-53 -24 V-60 11 i- 'V-92 25 V-76 -11 -V-83 -15 V-115 -10 V-99 5 V-106 7 3AC -56 3AC 3AC -56

8BA 18 13BA -26 8CB 26

.13CB -23 18CB 29 18BA 34 ,

'28CB. 26 28BA 17 28AC 10 38AC 40 33CB -17 33BA -16

'38BA 40 36AC- .0 38CB 54 4

4 4

t 4

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._ _ ._ u - - -,. _,.,_,. . . _ - , _. . . _ _ . - . _ _ _ _ _ . , _ _ _ . _ . . - , . _ - _ - _

L.

- CONTAINMENT SYSTEMS a

BASES 4

- 3/4.6.1.6 REACTOR BUILDING STRUCTURAL INTEGRITY

, This limitation ensures that the structural integrity of the containment will

be maintained comparable to the original design standards.for the life of the f facility. Structural integrity is required to ensure that the. containment will'-

} withstand the maximum pressure of 47.1.psig in the event of a steam line break accident. The measurement of containment tendon lift off force, the tenelle tests of the tendon wires, the visual examination of ~ tendons, anchorages and exposed interior and exterior surfaces of the containment, and the Type A leakage test are sufficient to demonstrate this capability.

The tendon lift off forces are evaluated to ensure that 1) the rate of tendon force loss is within predicted limits, . and 2) a minimum required prestress level exists in the. containment. In order to assess the rate of force loss, the lift off force for a tendon force is compared with the force predicted for the tendon. This predicted force includes a tolerance on force losses which are: +20% for concrete shrinkage, +25% for concrete creep, and +15% for stress relaxation. The resulting force is referred to as the Lower Limit force.

I In order for the tendon lift off. force to be indicative of the level of pre-

. stress force in the containment, each measured ferce must be adjusted for the known ~

differences which exist among the tendons due to original stressing force and elastic shortening loss. This adjustment is accomplished through the use of a Normalizing j- Factor (NF (t)). This factor is added to the lift off force, which results in the f

Normalized Lift Off Force. The Normalizing Factor is given by:

~ "+

, NFi (t) = [Fave(o) - Fi (o)] [1 SR(t)]

100 + AFes ( 2N ]

[F e( ) - F (o)) f is the group average lock-off force at original stressing,

{ minus,the original stressing force for the specific tendon.

i SR(t) is stress relaxation (percent) which occurs at time t af ter original stressing.

]

i T

AF is the total elastic shortening tendon force loss,

] es i

n is the stressing sequence comprising the specific tendon.

N is the total number of stressing sequences for the group of tendons a which comprise the specific tendons.

i refers to the specific tendon.

t refers to the time after original stressing of the current inspection period.

The surveillance requirements for demonstrating the containment's structural

. integrity are in compliance with the recommendations of Proposed Revision 3 to '

Regulatory Guide 1.35, " Inservice Inspection of Ungrouted Tendons in Prestressed 1 b g-,r--- , - ,,-,rm-e,----e.---- -we -.r-- - -, - , --- -- - - - - - ~ . - - . . - - - - - - - - - - - - - - - -- ~

. . ... . .__= , . .-. -

f ., CONTAINMENT SYSTEMS BASES (Continued)'

Concrete' Containments," April 1979; and Proposed Regulatory Guide l.35.1, " Inservice Surveillance of Ungrouted Tendons in Prestressed Concrete Containment Structures,"

April 1979.

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ATTACmiDIT I Page 1 of 6 .

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DISCUSSION s

1. Item 4.6.1.6.1.a One NRC comment with which we do not disagree pertains to Tech Spec Item 4.6.1.6.1.a. Here they require a list (table) of acceptance force values to be provided for each surveillance tendon. We feel that this requirement is met by a table containing either (1) th'e coefficients of the predicted

[ force-logtimeequationforeachsurveillancetendon,similartoSONGS2,or (2) the force predicted for each surveillance tendon at each inspection..

However, some^ discussion of these predicted forces, especially the " upper limit", is required.

We believe that only the lower limit value (as defined by Proposed Reg Guide 1.35.1) 2nd.90%'of this lower limit are required to be specified in 4.6.1.6.1.a, based on the requirements contained in Section 7.1 of Reg Guide 1.35(3). Here it states that the measured tendon force "... should be within the limits predicted for the time of the test." The limits are the upper and lower limits defined in Reg Guide 1.35.1. However, according to Sections 7.1.1.through 7.1.4 the accentability of the measured tendon force is determined from a comparison with its lower limit and 90% lower limit values only. Therefore, an upper limit on tendon force is not required to establish tendon acceptability. Nevertheless, we believe that an upper

. limit on the meas *1 red force equal to its initial stressing (lock-off) value is important from the standpoint of discovering errors in the stressing records or flagging tendons which might be overstressed relative to the

! Code allowable, in which case the tendon force would be reduced.

For the reasons discussed above, an upper limit force for each tendon equal l to its initial stressing force has been specified in SP-228, and this is a constant value with respect to time. However, these values would appear

only in the surveillance Procedures. They would not appear in the VCS Tech Spec since Reg Guide 1.35(3) does not requirethatexceedence,of.,tg.,,,.y2 upper limit be a reportable condition, and considering the NRC co= ment to the VCS Tech Spec that failure to meet any of the acceptance criteria in the Tech Spec is reportable as per Spec 6.9.1. In addition, if any acceptance

Attachment 1 Page 2 of 6 -

criteria is not met the ACTION statement appearing in SONGS 2 would become effective. This ACTION is not warranted if the tendon has too much force.

Also the reportability and ACTION requirements become even more illogical if the upper limit includes predicted tendon losses and a measured tendon force happens to be above this upper limit. In r'eality a teIndon may not lose as much force as predicted. This is not a condition which requires a report ta the NRC, and certainly it does not warrant the initiation of the ACTION requirements in SONGS 2.

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2. Detensioned/Retensioned Tendons -

Regarding the NRC co= ment on the last paragraph of Item 4.6.1.6..l.c of the

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VCS Tech Spec, this paragraph is properly placed as shown since this item addresses tendon detensioning, and the 3" limit on lock-off and the 5%

limit on elonga, tion only apply to those tendons which are detensioned and then retensioned. Also, a reporta'bility require =ent is intentionally nob indicated in the VCS Tech Spec because Sections 7.2 and 8.0 of Reg Guide 1.35(3) do not require a report, on'ly an evaluation, if the 5% elongation

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requirement is not met. The 3% recensioning force requirement does not appear in Section 7.0 of Reg Guide 1.35(3), but it was included in the VCS Tech Spec for completeness. However, if all failed criteria in the Tech Spec are to be reportable, as per the NRC comment, then the 3% and 5% limits should not appear in fae Tech Spec'. We believe that these two limits should be a procedural requirement, and they do appear in SP-228. However, if by merely appearing in the Tech Spec they are subject to reportability, then

'they should be deleted. Note also that by appearing in the Tech Spec they

{ are not only reportable but they are subject to the ACTION statement appearing in SONGS 2. Failure to meet the 5% elongation limii should be evaluated, but such a condition does not warrant the specified ACTION.

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3. ACTION Statement In general, the ACTION statement appearing in SONGS 2 literally applies to l all criteria in the Tech Spec. These include: the 5% limit on grease.. voids @

free water limit, physical appearance, chemical limits on grease, absence of corrosion, wire strength limit, limits (upper and lower) on tendon force, "no apparent change ... in visual appearance of end anchorages", etc.

Failure to meet the criteria on these items should be evaluated as to cause, l

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- . Attachment I Page 3 of 6 but these conditions do not warrant the procedures specified by the ACTION in SONGS 2. It is for this reason that the ACTION statement in the VCS Tech Spec appears as it does in two parts.

The only tendon force conditiori which warrants the ACTION specified by SONGS 2 (or VCS 3.6.1.6.a) is if thu forces in the tendons are less than those required to satisfy the minimum compressive stress requirements in ,

containment. These compressive stress requirements are a function of a value of kips /ft. for vertical tendons or external pressure for hoop and

- dome tendons. These loads can be translated into average tendon force for each tendon group. For VCS these values are specified in Item 4.6.1.6.1.b.

This is an additional requirement but it does not appear in Rek Guide 1.35(3). However, it does appear in the current draft of a future ASME Code which will provide rules for tendon surveillance and inservice inspection of concrete containments.

() Thus, there is a dual criteria on measured tendon forces: (1) the individual force comparison to detect .:bnormal rates of force decline, and (2) the minimum force required of the tendens. Satis ~

fying (1) does not guarantee that (2) will be met.

The NRC has cot:mented that an " average tendon force" is not acceptable to their Structural Engiaeering Branch. Their concern is for values of force below the average over a large region of the containment and that the com-pressive stress in the concrete in'such a region remains below its wh4=m required value. In light of this concern, we would agree to delete the word " average" from Item 4.6.1.6.1.b. However, we maintain that the minimum force values appearing in Item 4.6.1.6.1.b are the only criteria which would warrant initiation of the ACTION statement appearing in the SONGS 2 Tech Spec or ACTION statement 3.6.1.6.a in the VCS Tech Spec. Our position

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appears to be supported by the provisions of paragraph 50.36 (Technical Specifications) of 10CFR50 which is quoted below:

" Limiting Condition for Operation. Limiting conditions for operation are the lowest functional capability or performance levels of equipment required for safe operation of the fac.ility ".4.nr-O

( ASME Boiler and Pressure Vessel Code; Section XI-Div. 1, Rules for Inservice Inspection of Nuclear Power Plant Co=ponents; Subsection IVX - Inservice Inspection of Concrete Containments, draft dated January, 1982.

._ . Attachment I Page-4 of 6 Of all tha survaillance acceptenca criteria, only the minimum required tendon forces are a measure of the "lovest functional capability ... re-quired for safe operation of the facility".

4. Item 4.6.1.6.1.c.1 In Item 4.6.1.6.1.c.1 of the VCS Tech Spec, the NRC has questioned the use of the phrase "specified acceptance limits" on the corrosion of the sample wire. In response, the acceptance limits referred to those specified in '

SP-228, and they consist of the five letter-rated conditions used for

, classifying the degree of corrosion on the wire or the limits on slips' and splits for the button' heads.

The SP-228 procedures require that to establish whether the corrosion, cracks, or damage which may be observed on a test wire indicate an unusual or abnor=al condition the orig.inal buttonheading records are to be reviewed.

These records document the corrosion condition of the tendon wires ,at the-,

time the tendons were installed and identify the number of buttonheads on a tendon which had slips or splits (cracks) outside the specified acceptance limits. This comparison in conjunction with engineering judgement allows an evaluation to be made as to whether the wires (using the test wire as a sa=ple) have experienced an abnormal deteriorating condition. For example, we do not consider that the change from an A to 3 or B to C rating is classified as "abnor=al"; however, this judgement is part of the evalua-tion process and it is practically impossible to quanitfy in the Tech Spec. For this reason we would propose to revise Iten 4.6.1.6.1.c.1 to

. read:

That over the entire length of the tendon wire, the wire.has .

not undergone corrosion, cracks, or damage to the extent that an abnormal condition is indicated.

We believe that'the above wording satisfied the requirements of Reg Guide 1.35(3). We also point out that the SONGS 2 Tech Spec wording for this iten requires that the wires be free of corrosion, cracks, and damage.

This criteria vill be practically impossible to satisfy. Slips oi'spli'ti "U (cracks) do occur on the wires, and a light oxide coat (corrosion) on the wire may also be present.

.. Attachment I Page.5 of 6

5. Item 4.6.1.6.1.d In Item 4.6.1.6.1.d, the NRC com=ent refers to Item 4.6.1.6.d of SONGS 2 for an acceptable criteria for the grease. The 5% limit on voids (as a percent of net duct volume) is consistent with Reg Guide 1.35(3), and we would agree to specify this in the VCS Tech Spec; however, the ACTION re-quired in SONGS 2 if the 5% limit is not met is not warranted. Other grease criteria in SONGS 2 which should be changed are:

a. Njt free water in the grease is required. However, a 10%

limit on free water content is generally acceptable. This limit appears in Reference 1.

b. Chemical properties. are required to be within acceptance limits "specified by the grease manufacturer". However, tests on only the chemical properties which directly affect corrosion resistance are necessary. These properties are -

Chlorides, Sulphides and' Nitrates. The grease manufacturer limits these to 4 PPM for the Chlorides and Sulphides and 2 PPM for the Nitrates for the fresh grease supplied for the project.

Howev.er, higher li=its are permitted for the existing grease in the tendons. The ASME Concrete Containment Code and Reference 1 specify 10 PPM. Therefore, the limits specified by the grease manufacturer, which apply to fresh grease, are not appropriate for the grease re=oved from the tendons at a surveillance.

6. Visual Insoection s

Visual inspection of three distinct areas is required by Reg Guide 1.35(3):

(1) End anchorages, (2) Concrete adjacent to these anchorages, and (3)

Exterior containment surfaces. Items (1) and (2) are designated by Section 3.2 of Reg Guide 1.35(3). The acceptance criteria is "no abnormal material behavior". In the SONGS 2 Tech Spec, Item 4.6.1.6.c.2, the ceptance criteria is stated as "no apparent changes have occu,rred,in ,th3 _g visual appearance ...". These two criteria are significantly different, and it vill.be practically i=possible to neet the "no apparent change" criteria.

,, , Attachment I Page 6 of 6 Section 3.1 of the Reg Guide 1.35(3) requires visual inspection of exterior concrete surf aces to detect areas of widespread cracking, spalling, and grease leakage". Also Appendix J.V'of 10CFR50 requires that "a general inspection of the accessible interior and exterior surfaces ,of the con- ,

tainnent structures and components shall be perforned prior to any Type A

. test to uncover any evidence of structural deterioration . . .". Thus, the visual inspection required by Reg Guide 1.35(3) is included as part of the Integrated Leak Rate Test program. Both the VCS and SONGS 2 Tech Specs have specified the Containment Surface inspection in this nanner.

However, both Tech Specs use the phrise "no apparent changes", which should be deleted. .

O 4 - - . .- % u ? "b' l

ATTACHMENT A

,e' V. C. SUMMER TECH SPEC 3.6.1.6/4.6.1.6 WITH NRC COMMENTS O

) %E .

4E **e

Attachment A * ,

Pags 1 of 3 ,~~

s , , .

CONTAINMENT SYSTEMS .

[0NTAIhMENT STRUCTURAL INTEGRITY ,

LIMITING CONDITIONS FOR OPERATION .

3.6.1.6 The structural integrity of the containment shall be maintained at a level consistent with the acceptance criteria in Specification 4.6.1.6.

PPLICABILITY: ' MODES 1, 2, 3 and 5.

ACTION:

~

a. With the structural integrity of the containment not conforming to the requirements of 4.6.1.6.1.b, perform an engineering evaluation of the structural integrity of the containment to determine if COLD q

SHUTDOWN is required. The margins available in the containment .

design may be considered during the investigation. If the gfh q gcceptabilitl of the containment tendons cannot be established within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, restore the structural integrity to .within the -

hd {

l limits within 24 h6urs or be in at least HOT SIANDBY within the next -

6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWN within the*following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />.

b. With the structural integrity of the containment otherwise not ,

conforming to the requirements of Specification 4.6.1.6 submit a

. report to the Commission pursuant to NRC Reg. Guide 1.16. This report shall include a description of the , tendon condition, the condition of the concrete (especially at tendon anchorages), the ,

inspection procednres, the , tolerances;on cracking, and the '

corrective actions taken. -

SURVEII. LANCE REQUIREMENTS ' s

\

4.6.1.6.1 Containment Tendons. The structural integrity of the containment "r.._ shall be demonstrated at the end of one, three and five years following the initial containment structural integrity test and at five year intervals thereafter. The structural integrity of the tendons shall be ~

demonstrated by:

mining G.m fr^ resentative sample

• of at least 15 tendons p/ (4 i ome, 5 vertical and hoop) each has a lift off force e,qualling, '

D<,Y g hghp excee ing, its lower limit predicted for.the time of the test.

gThis1 er limit is based on,the predicted tendon force and it includes Q gg sN -

• g Those tolerances are: gC9 e b +a to erance 4 for on the concretc. tendon force shrinkage, +25%losses.

for concrete creep, and +15% for 9 0 tress relaxation of the tenaon. R[g g s

• For each inspection, the tendons shall be selected on a

) random but representative basis so that the sampic group will change somewhat for each inspection; however, to develop a history of tendon performance and to correlate the observed data, one tendon from each group (dome, vertical, and hoop) may '

be kept unchanged after the initial selection. ,

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Attachment A Eage 2 of 3 ,

CONTAINMENT SYSTEMS SURVEII.I.ANCE REQUIREMENTS (Continued)

If the lift off fo'rce o,f a selected tendon in a group lies between the prescribed lower limit and 90% of that limit, one tendon on each side of this tendon shall be checked for its lift off force. If the lift off forces of the adjacent tendons are equal to, or greater than, their prescribed lower limits at the tiee of the test, the single deficiency shall be considered unique and acceptable. If the

. lif t off force of either of the adjacent tendons lies below the tendon, the condition is reportable.

_< prescribed lower limit for that If the lift off force of any one tendon lies below'90% of its f q,( prescribed tendon. It shall lower limit,.the be completely tendon detensioned andshall be considered a determination n..li_ _. ~

made L1-.

a de'fe

( (. as to the cause "of the occurrence. ceu .

41

/'\ k X.5 b. Determining that the average of the normalized

• tendon lif t off tu"f g

forces for each tendon group (vertical, dome and hoop) is equal to, #

or greater than, 1195 kips for vertical tendons, 1115. kips for dome' W p g tend' o

ns,the andcondition for hoop tendons.

1181 k,ips[is repcrrtable.

If this requirement.is. fp d not met, O d

c. Detensioning one tendon in each group (dome, vertical and hoop) from the representative sample. One wire shall be removed'from each .

detensionel tendon and examined to determine:

1. That over the entire.lengt! of the vi,re, the tendon wire has not undergone corrosion, cracks or damage beyond that .

which was or~iginally recorded and the extent of corrosion is ified accepta b limits'. 1. i l m - L _ f,

- , witng f

p ,

2. A minimum tensile strength value of 240,000 psi ,

(guaranteed ultimate strength of the tendon material) for at least three wire samples '(one from each end and one at mid-length) cut from each removed wire. Feiluva af any one-cf d.u wue suples tu mat th e + 4"m *nneita ermgth t~ t ir =pertchla

• Each tendon shall be retensioned to within 3% of its lift off force measured prior to detensinn4nn. fuponretensioning,theelongation, hl be wunin plus or minus ST. of that recorded at original stressing of the tendon. If the 5% limit is not met, an -

investigation shall be made to determine if wire failure is the a

g In order for the tendon lif t off forces to be indicative of the average level of prestress, each lift off. force adjusted for differences wh,ich exist among the tendons due to initial ock off force and elastic '

shortening loss.

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(

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• Attachment A Page 3 of 3 ,

CONTAINMENT SYSTEMS SURVEILLANCE REQUIREMENTS (Continued)

d. Determining for each tendon in'the above representative sample, that an analysis of a sample of the sheathing filler grease for voids,,

g40 contaminants, and free water, establishes its suitability as a

,gf corrosion-inhibiting medium.,

If the inspection performed at one, three And five years indicate no abnormal degradation of the post-tensioning system, the number of tendons selected for subsequent surveillances may be reduced to a representative sampic of at least()) tendons *s (3 dome, 3< vertical and 3 hoop). - _

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4.6.1.6.2 End Anchcrages and Adjacent Concrete Surfaces. The structural integrity of the end anchorages of all tendons inspected pursuant to Specification 4.6.1.6.1 and the adjacent concrete surfaces shall be determined through visual inspection. The condition of the end anchorage and adjacent concrete shall be recorded. Concrete cracks exceeding a specified width shall be documented. Changes in the condition of the end anchorage or the concrete p7 7 from that'previously recorded shall be noted on the record. Any condition or -

H change in condition which'.ind{ cates abnormal material or structural

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is reportabic.

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4.6.1.6.3 N%

Containment Surfrees. The structural integrity of, the exposed

) accessible interior and extdrior surfaces of the containment, including the -

liner plate, shall be determined during the shutdown for each Type A containment leakage rate test (Specification 4.6.1.2) by a visual inspection of these surfaces. This inspection shall be performed prior to the Type A containment leakage rate test to verify no apparent changes in appearance or' other abnormal degradation. Any apparent change in appearance or other abnormal degradatibn is reportable. -

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e ATTACHMENT B e=

SONGS 2 TECH SPEC 3.6.1.6/4.6.1.6 WITH NRC COMMENTS ,

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Attachment B g4 Page 1 of 5 i . "; I : *. U. '. ' ! . N !0; w ;!.lii!;.'.

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3.6.1.6 lhe structural integrity of the containment shall be maintained at a level consistent with the acceptance criteria in Specification 4.6.1.6. ..

APPLICABILITY: MODES 1, 2, 3 and 4.

ACT 10tJ:

With the structural integrity of the containment not conforming to the above requirements, perform an engineering evaluation of the containment to demo 1 strate its structural integrity within 72 hot.rs; otherwise, be in at least H01 STAtiDBY l within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in COLD SHUTDOWr! within the follosing 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. l SURVEILLAt:CE REQUIREMEt1TS 4.6.1.6 The containment's, structural integrity shall be demonstrated at ,

the end of one, three and five years af ter the initial structural integrity .. I test (ISIT) and at five year intervals thereaf ter with the exc.egition of tendon lift off force and tendon detensioning and material test and inspection which j shall be determined at the end of one, five and ten years following the ISIT +

and at ten year intervals thereafter. The d.W W structural integrity shall I be demonstrated by: /,V(2 1N I f4$l4 y,4 O

a. Determining that tendons selected in accordance with Table 4. 1  ;

have a lif t off force between the maxintum and minimum valve at i the first year inspection. For subsequent inspections, for endons I and periodicities per Table 4.6-1, the maximum first year lif t off JM ,

forces shall be decreased by the amount X1 log t kips for U tendons $ld .

and Y1 log t kips for hoop tendons and the minimum lift off force shall be decreased by the amount X2 log t for U tendons and Y og gr o fI  ;

l t for hoop tendons where t is the time interval in yeap om geg initial,,J P y2 i tensioning of the tendon to the current testing date. x This test s  ;

shallincludeessentiallyacompleteunloadingofatendonselected1o:Tk N  ;

in accordance with Table 4.6-1 in which the tendon is detensioned to pl /M determine if any wires or strands are broken or damaged. Tendons g, y.'

found acceptable during this test shall be retensioned to their ,s A-observed lift off force, + 3%. During retensioning of these tendons,ba k. ,,d.

the change in load and eliingation shall be measured simultaneously g/ i at a minimum of.three, approximately equally spaced, levels of force d' between the seating force and zero. If elongation corresponding to a specific load differs by more than 5% from that recorded during installa-tion of tendons, an investifation should be made to ensure that such difference is not related to wire failures or slip of wires in anchorages.

If the lift off force of any one tendon in the total sample population 's below the predicted bounds but greater than or equal to 90% of the predicted lower bounds, an adjacent tendon on each side of the defective tendon shall also be checked for lift off force. If both of these adjacent tendons are found acceptable, the surveillance program may proceed

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. i a Attachment B Page 2 of 5 suir.'l l t i , NCI _ , _ . _ , . _ _ _ _ . . _ . . . _ . _ . . .

110llllli lh u l b Il'..a.t i nued) considering the single deficiency as unique and acceptable. The tendon (s) shall be restored to the required level of integrity.

771 ore than one tendkbelow the predicted boundr out of the original do#O sample population is evidence of abnormal -iegradation of the contain-ment structure. -94=mc h a

b. Performing a tendon detensioning and material test and inspection of 4 a eviously stressed tendon wire or strand from one tendon of each group, and determining that over the entire length of the removed g),bwire or strand that:

1. The tendon wires or strands are free of corrosion, cracks and damage.

2. A minimum tensile strength value of 270 ksi (guaranteed ultimate strength of '.he tendon material) for at least three w*re or strand samples (cne from each end and one at mid-length) cut from each removed wire or strand. Failure of any one of the wire or strand samples to meet the minimum tensile strength test is evidence of abnormal degradation of the containment structure. , _.

c. Performing a visual inspection of the following:

1. Containment Surfaces - The structural integrity of the exposed accessible interior and exterior yurfaces of the containment, including the liner plate, shall be determined during the shutdown fo each Type A containment leakage rate test (Specfication 4.6.1.2) a visual inspection of these surfaces and verifying no apparent changes in appearance or other abnormal degradation (e.g., widespread ad ( g foj cracking, spalling and/or grease leakage).

) 2. End Anchorages - The structural integrity of the end anchorages (e.g., bearing plates, stressing washers, shims, wedges and buttonheads) of all tendons inspected pursuant to Specification 4.6.1.6a shall be demonstrated by determined through inspection that no apparent changes have occurred in the visual appearance of the end anchorage, l 3. Concrete Surfaces - The structural integrity of the concrete surfaces adjacent to the end anchorages of tendons inspected pursuant to Specification 4.6.1.6ct shall be demonstrated by visual examination of the crack patterns to verify no abnormal material behavior.

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.t utiTAltiMEr.T SYSTEM 5 Attachm:nt B Page 3 of 5 SURVEILLAtlCE REOUIREMEfJTS (Continued)

d. Verifying the OPERABILIGY of the sheathing filler grease by the following:

1. tio significant voids (in excess at 5% of the net duct volume), or the presence of free water, within the grease filler material, taking

_ into account temperature variations.

2. tio significant changes have occurred in the physical appearance of the sheathing filler grease.

3. Minimumgreasecoverageexistsfordifferengtpartsoftheanchorage system.

4. Chemical properities are within the acceptability tolerances specified by the sheathing filler grease manufacturer.

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Attachment B page 4 of 5 m.

in jf1 TABLE 4.6-1 l TENDON SURVEILLANCE TD; DON hTMI.ERS l

Years Af ter Initial Structural 1 3 5 10 Integrity Test 15 Type of Inspection H U H U H U H U H U Visual Inspection 20 31-121 5 13-139 42 64-178 of End Anchorages 86 9-143 36 35-117 86 9-143 97 66-176 50 12-140 and Adjacent 97 66-176 79 4-58 75 94-148 86 9-143 11 4 5-57 Concrete Surface 53 88-1.54 11 3 78-164 9 19-133 53 39-113 13 96-146 A4 R7 108 20 31-124 42 64-178 l Prestress 86 9-143 ' 86 9-143 97 66-176 Monitoring 97 66-176 75 94-148 86 9-143 Tests 53 88-154 9 19-133' 53 39-t 3-64 !na Dentensioning and 20 88-154 42 19-133 97 66-176 Material Tests TDiLON NUMBERS Years Af ter Initial Structural 20 25 30 35 40 Intacrity Test ,

Type of Inspection H U H U H U H U H U Visual Inspection of End Anchorages 75 86-156 12 24-128 86f 9-143 81 41-111 20 9-143 and Adjacent 86 9-143 90 70-172 31 69-178 109 90-152 86 31-121 Concrete Surface 9 43-109 25 76-166 64 94-148 31 50-102 LO8 86-156 Prestress 75 86-156 86 9-143 20 9-143

! Monitoring 86 9-143 31 64-178' 86 31-121 l Tests 9 43-109 64 94-148 LO8 86-156 Detensioning and 75 43 109 31 64-178 86 9-143 Katerial Tests a *,

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SAN ONOFRE-UNIT 2 3/4 6-12 l FEB 181931

,' Attachment B Page 5 of 5 TACLE 4.6,7_.

TEf1D0ft LIFT-0FF FORCE U TENDON TENDON FIRST YEAR NUMBER Maximum (kips) Minimum (kips) X1 }j([

9 20 31 42 53 64 75 86 97 108 HOOP TENDON TENDON FIRST YEAR -

NUMBER Maximum (kips) Minimum (kips) Y1 Y2 43-109 39-113 31-121 19 ,133 9-143

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94-148 88-154 86-156 66-176 64-178 l SAN ONOFRE-UNIT 2 3/a 6-l?a L