ML20214P514
| ML20214P514 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 11/07/1986 |
| From: | Haynes J ARIZONA PUBLIC SERVICE CO. (FORMERLY ARIZONA NUCLEAR |
| To: | Kirsch D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| REF-PT21-86-378-000 ANPP-38972-JGH, DER-86-20, PT21-86-378, PT21-86-378-000, NUDOCS 8612040242 | |
| Download: ML20214P514 (17) | |
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t Arizona Nuclear Power Project " /g P 0. BOX 52034
- PHOENIX. ARIZONA 85072-2034 h/
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'/4 November 7, 1986 ANPP-38972-JCII/DJW/DRL-92fl1 U. S. Nuclear Regulatory Commission Region V 1450 Maria Lane - Suite 210 Walnut Creek, California 94596-5368 Attention: Mr. D. F. Kirsch, Acting Director Division of Reactor Safety and Projects Palo Verde Nuclear Generating Station (PVNGS)
Units 1, 2, 3 Docket Nos. 50-528, 529, 530
Subject:
Final Report - DER 86-20 A 50.55(c) and 10CFR21 Condition Relating to Damper Seals Not Meeting Required Specifications File: 86-006-216; D.4.33.2
Reference:
(A) Telephone Conversation between R. C. Sorenson and D.. R. Larkin on June 3,1986 (Initial Notification -
(B) ANPP-37195, dated July 2, 1986. (Interim Report -
(C) ANPP-38392, dated September 24, 1986. (Time Extension -
Dear Sir:
Attached, is our final written report of the deficiency under 10CFR50.55(e) referenced above. The 10CFR21 evaluation is also included.
Very truly yours,
/1Lhf J. C. IIay es Vice President Nucicar Production JGil/DRL:kp cc: See Page 2 8612040242 861107 DR ADOCK0500g8
$ ~ d 'l
DER 86 Final Report Mr. D. F. Kirsch Acting Director Page Two November 7, 1986
.ANPP-38972-JGH/DJW/DRL-92.11 cc: J. M. Taylor .
Office of Inspection and Enforcement U. S. Nuclear Regulatory Commission Washington, D. C. 20555 A. C. Gehr (4141)
R. P. Zimmerman (6295)
Records Center Institute of Nuclear Power Operations 1100 Circle 75 Parkway - Suite 1500 Atlanta, Georgia 30339
',k-:.
4 FINAL REPORT DER 86-20'
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DEFICIENCY EVALUATION 50.55(e)
ARIZONA ~ NUCLEAR POWER PROJECT.(ANPP)
PVNGS UNITS 1, 2, 3
. I. Description of Deficiency t
.The HVAC dampers;used for isolating the control room, during emergency
, conditions, are required by FSAR Section 6.4.2.2.2.J to be "bubbletight."
The specification for bubbletight dampers requires that with a maximum
. differential pressure of 30-inches of water across 'a closed damper, no apparent-leakage would be discernible when the damper is subjected to soap solution testing as per ANSI'N.510-1975 Paragraph 6.5. The control room essential ventilation system is required by FSAR section 6.4.2.4.A to maintain an 1/8-inch' water gauge positive pressure differential between the control room and adjacent areas with no more.than 1000 cfm filtered makeup air to compensate for leakage from the control room pressure boundary. This design prevents infiltration of unfiltered contaminated air (FSAR Section 6.4.2.4.A) and thus ensures that operator exposures do not exceed general design criteria (GDC) 19 limits. The isolation dampers are also required for isolating the control room essential ventilation system to minimize infiltration of smoke or toxic gas into the control room (FSAR section 6.4.3.3).
While doing rework per NCR SM-6272 to fix an incorrectly installed damper,-the HVAC subcontractor discovered that the blade seal on a Unit 3 damper, Tag Number. 3M-HJB-M57 had a tear. (Damper 3M-HJB-H57 is a normally closed, 40-inch diameter bubbletight damper in the control room smoke exhaust system and is used for control room isolation.) The tear
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. condition was documented on NCR MJ-3108. The seal material was replaced withis similar seal and, af ter the damper was cycled a few times, the seal tore again. The observed tear would allow some leakage of air through the damper. With the damper in this condition, the ability to maintain a positive pressure inside the control room or to isolate the control room is indeterminate.
Further investigation revealed that the manufacturer had installed 50
, durometer seal material on the damper instead of the 60 durometer
- material used in the environmental qualification of the prototype damper. The investigation also reve.aled that when the blade of damper l.
3M-HJB-H57 is in the closed position the clearance (gap) between the blade and the frame ranges from a mtnimum of 1/16-inch to a maximum of 1/4-inch. The manufacturer has stated that the clearance should be approximately '3/16 + 1/32-inch.
There are a total of 25 "Q" class bubbletight dampers used in each nuclear unit. ~ Four of these are classified as " watertight" and serve the auxiliary feedwater pump rooms located in the main steam support
,i structure. The other 21 serve the control room essential ventilation system. Twenty of these dsmpers provide control room isolation and pressurization during the essential ventilation mode, and one damper
- provides computer room isolation during the halon system actuation. All bubbletight dampers are manufactured by the Ruskin Manufacturing Company.
Evaluation The bubbletight dampers were procured by The Waldinger Corporation (TWC) from Ruskin Manufacturing Company under the Bechtel 134{K-598 subcontract specification. . The blade seal material for these dampers as specified by Ruskin is gray commercial grade, silicone rubber, supplied by the Mosite Rubber Company and made to Federal Specification ZZ-R-765. The silicone sheet stock, af ter being manufactured by the Mosite Rubber Company, is shipped to Metro Gasket Company where it is cut to the required size and
. delivered to Ruskin. These dampers, ranging in size from 10-inch to 48-inch diameter were environmentally qualified by prototype testing to withstand 300 operation cycles over a five year period. The seal material installed in the prototype has a hardness of 60 durometer.
The evaluation of the problem focused on two potential concerns; use of seal ca erial not covered by the environmental qualification testing and/or insufficient clearances between the damper blade and frame.
To determf.ne the extent of the problem and establish the root cause, a program of inspection and testing was implemented. The following are the details of this program.
A. Startup work authorization (SHA) No. 10391 and NCR SM-6628 was written to direct TWC to:
- 1. Investigate all dampers in Unit 3. The purpose of this inspection was to:
- a. Determine the condition of the seal material.
- b. Map blade to frame clearances for these dampers,
- c. Cycle the dampers 30 times and record any problems found.
-2. Map blade to frame clearances of bubbletight dampers used during equipment qualification.
- 3. Verify the mechanical properties (hardness, tensile, tear) of the seal material installed on these dampers.
- 4. Perform an operational test (300 cycles) on unaged seal material using damper 3H-HJB-M57 to determine sensitivity of seal IIfe to hardness.
The results of the SWA and NCR inspection and testing are as follows:
- 1. Inspection of Unit 3 Dampers A summary of Unit 3 field measurements of blade to frame clearances is shown in Table 1 (Attached). Per Table 1. nine out of 25 dampers had blade to frame gaps that exceeded the maximum clearance and seven out of 25 that were under the minimum clearances as measured on the prototype dampers that were used in the environmental test. Since some of the inspected dampers had both undersize and oversize gaps, there
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were 13 dampers overall that exhibited '"out .of spec" blade to
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frame clearances. Also, as required -by SWA 10391, all.14-inch 4
. L diameter and larger dampers were cycled 30 times and functioned
- satisf actorily. - This cycling was conducted to determine if the operability of the dampers was affected by the possible.
. undersize gap condition.
F During the inspection, one 48-inch damper, 3M-HJA-M52, was found' with a pinhole in the seal and one 14-inch damper, 3M-HJA-M03, was found with a small tear near the axle.~ ~ Both conditions were documented on NCR SM-6531 which was dispositioned to replace the f seal material on both dampers. The pinhole in the seal of damper 3M-HJA-M52 and the tear 'in the damper 3M-HJA-M03 do not i follow the pattern of failure due to presence of small gaps or soft-seal material as observed by engineering during testing and inspection of 3M-HJB-M57. .The pinhole in the seal of damper 3M-HJA-M52 is attributed to a manufacturing imperfection in the seal material. The tear in damper 3M-HJA-M03 .is attributed to a foreign object which penetrated the seal during the i construction / installation period. Both the tear and the pinhole
( in dampers 3M-HJA-M03 and 3M-HJA-M52 are considered isolated -
conditions.
- Other than the three problems discussed above (3M-HJA-M52, j 3M-HJA-M03 and 3M-HJB-M57 discussed under the description of i- deficiency section), the dampers showed no signs of significant j physical distress and no tearing of.the seal material.
l Af ter its blade seal was replaced, damper 3M-HJA-M52 was subjected to soap solution tes'ing t and failed to maintain a bubbletight seal, so NCR MJ-3165 was written. The maximum blade j gap on this damper was excessive; 7/16-inch. This oversize gap i did not allow for sufficient blade seal to frame contact to effect a tight seal and, thereby,-allowed air to blow by when pressure was applied to one side of the damper during the soap solution test.
To address this oversize gap condition, evaluation and testing was performed by Ruskin at their factory. As a result of this evaluation, it was concluded that gaps equal to or smaller than 3/8-inch are acceptable for all dampers (Reference 4). Damper 3H-HJA-M52 was subsequently reworked, to ensure a maximum gap of equal to or smaller than 3/8-inch, was obtained. Damper 3M-HJA-M52 successfully passed the required bubbletight pressure test af ter completion of the rework.
- 2. Gap Measurements for Qualification Dampers s
The gap measurements for dampers used during seismic qualification prototype testing are shown in Table 1. The qualification tests were conducted on dampers that had radiation aged 60 durometer seal material. The minimum and maximum gaps measured on the qualification dampers are also shown in Table 1.
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32 - Tests on ' Seal Material. Properties To determine the adequacy of the seal material'for bubbletight -
application, samples from the seal of damper 3M-HJB-M67 and of the torn seal taken from damper 3M-HJB-M57 were sent to independent laboratories, by Waldinger and Ruskin, for analysis. According to manufacturing ~ records obtained by Waldinger, the-blade seals of these _two dampers were made from the same material batch. Tests were performed to determine if tensile, tear and hardness characteristics of the seal material
. were comparable.with the batch of the seal material originally used for environmental qualification.
The laboratory test indicated that 50 durometer material was used on these dampers. This material differs in tensile and hardness characteristic from the seal material used in the qualification program. The results of these tests are documented in reference 6.
Prior to the identification of this problem, the hardness characteristic of the seal material and its effect on the functionability of the bubbletight dampers was not identified.
The material specification referenced by Ruskin for the seal material, allowed a hardness range of 50 to 60 durometer. The Mosite Rubber Company performed a hardness test on each batch or seal material that was manufactured for use in the bubbletight
' dampers. Since the material specification provides a lower and .
an upper limit for hardness, the possibility existed that blade seals manufactured with material hardness.of as low as 50 durometer could have been installed on other dampers.
To investigate this potential condition, TWC, Ruskin 'and Mosite researched their purchase order and manufacturing records on all Q class, bubbletight dampers supplied to Unito 1, 2 and 3 to determine if seal material with a hardness of less than 60 durometer was'used on any other dampers. The results of this investigation, as documented by reference 7, indicate that the batch of seal material used on 3M-HJB-M57 and 3M-HJB-M67 was installed on only three other dampers in Unit 3 and one in Unit 2 (3M-HJB-M56, 3M-HJA-H56, 3M-HJA-H57 and 2M-HJB-M67). All these dampers had 50 durometer seal material. Per NCR's listo s under Section III, all Unit 3, 50 durometer blade seals have been replaced. Damper 2M-HJB-H67 is installed in the control room essential ventilation system. -This damper is not a part of the control room pressure boundary and does not receive a control room essential filtration actuation signal (CREFAS) or control room ventilation isolation actuation signal (CRVIAS).
The function of this damper is to isolate the computer room in order to maintain a greater than 5% concentration of halon for 10 minutes in the event of a fire in the computer room, as required by NFPA-12A. Safety assessment and corrective actions for this damper are addressed under analysis of safety implications and section III respectively.
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- 4. Operational Cycle Tests on Unaged Seal Material To establish the sensitivity of seal life to hardness, a field cycle . test on unaged material using the damper first identified with a torn seal was performed by TWC under SHA No.10391.
- Damper 3M-HJB-M57 (40-inch) which has -a minimum blade to frame gap of :1/16-inch consistently tore the 50 durometer material in
-about 10 cycles,- but when the seal;was replaced with a 60 durometer unaged material, it successfully cycled 450 times (50 percent higher than the nominal-design life). - Upon examination the seal showed signs of wearing but no tears were found.
- 5. . Ruskin Cycle Test with 30-inch and 48-inch Diameter-Dampers To evaluate the effects of reduced gaps, Ruskin. performed additional cycle tests in their factory-(Reference 1) using 30-inch and 48-inch diameter prototype dampers with blade to frame clearances conservative 1y' set equal to, but spanning a .
length longer than-those found on the dampers during Unit 3 inspection. The tests were first-run with unaged seals. The 30-inch diameter damper test specimen passed the initial test (300 cycles) with both 50 and 60 durometer unaged material.
Ruskin continued testing the 30-inch diameter prototype.- The 48-inch diameter damper test specimen failed the initial test (at approximately 100 cycles) with 60 durometer unaged material, and hence the test was discontinued.
Ruskin continued testing the 30-inch diameter prototype damper with aged 60 durometer material and a minimum gap of 3/64-inch.
The configuration was cycled 300 times and when leak tested, met the bubbletight requirements.
Based on the inspection and -testing of these dampers as described above, the following conclusions can be made:
- a. The use of 50 durometer seal material greatly increases the chance of premature seal failure.
- b. Seal f ailure is dependent on blade clearances (gap) and production variations in blade geometry that affect the gap.
- c. The 48-inch dampers appear to be the most susceptible to seal damage caused by small gaps.
- d. The 30-inch and smaller dampers are less susceptible to seal damage caused by small gaps.
It 'should be noted that with the blade to frame clearances set at values equal to that of the original qualification prototype units and with 60 durometer seals, dampers with both unaged and aged seal material can withstand the number of open-close cycles corresponding'to the nominal design life of the seal.
(Reference 10).
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- 6. Inspection of Units 1 and 2 Dampers Prior to inspection of the dampers in Units 1 and 2, the control y room pressure envelope integrity was verifiea by control room pressurization test 73ST-9HJ01. The' test results showed that the control room pressure met the technica1' specification requirements of maintaining.the control room at a positive pressure greater.than.or equal to 1/8-inch water gauge.- This indicates that the dampers are performing their intended function. However, unfiltered air in-leakage may occur through four large 48-inch dampers, if these dampers have sufficient Eseal damage. Therefore, the-48-inch dampers (four per. unit) evere inspected, first in Unit-1 and then'in Unit 2. A summary of field measurements of blade to frame clearances is shown in i l Table 2.
Contractor work order (CWO) No. 177886 was issued to Waldinger to map the blade to frame clearances, perform seal replacement
.and correct blade to frame clearance irregularities as necessary for the Unit 1 dampers. No gaps smaller than the acceptance j tolerance were found. Damper IM-HJA-M01 was. found to have two
! small tears. The tear lengths were approximately 1/2-inch and 1
!. 3/4-inch long. These tears were not through tears and therefore
- l. the seal appeared to be maintaining its sealing integrity. The l characteristics of these tears did not follow the seal failure
- pattern that has been observed due to sof t seal or small gap.
l An engineering observation of damper IM-HJA-M01 revealed the presence of sharp burrs on the edge of the seal retainer ring at the location where the tears were present. ' The operation of the damper. is such that the seal lays over the edge of the retainer as the damper opens. The sharp burrs could then initiate a tear in the seal which results in tear propagation as the damper is l- cycled. The seal failure of 1H-HJA-M01 is attributed to the presence of the burrs on the retainer ring and is considered an
. isolated case. Sharp burrs were not found on the other removed l dampers in Units 1 and 2. Also the Unit 3 inspection did not identify any tears caused by burrs.
All four 48-inch diameter dampers in Unit 1 had clearances which exceeded the original specified tolerance of 1/4-inch. However, Ruskin's. evaluation M598-4564, "Bubbletight Dampers Blade Seal and Blade Gap Evaluation" (discussed previously under Unit 3 inspection section) reported that gaps of 3/8-inch are sufficient to ensure that the damper is qualified for the required service. Based upon this, only one damper (IM-HJB-M01) in Unit I required the gap tolerances to be reduced. This particular gap was measured to be 25/64-inch from the retainer ring to the damper housing, covering less thar; 1% of the circumference.
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t Contractor. work order (CWO) No. '178952 was issued to map'the
-blade'to frame' clearances, perform seal replacement and correct blade to frame clearance irregularities as necessary for the Unit 2 dampers. One damper (24-HJB 'M55) was found to have a gap -
which was less than the specified tolerance and a 17-inch tear.
'This tear was a through tear with seal material detached from the damper blade. The minimum gap was found to be at the midpoint of the 17-inch tear. This damper has been reworked in order to correct the gap tolerances and the-seal material for this damper'has been replaced. All four. dampers in Unit 2 were found to have clearances which exceeded the original specified i tolerance. These dampers met the maximum gap criteria as identified in M598-4564, "Bubbletight Dampers Blade Seal and Blade Gap Evaluation", discussed previously,:and therefore required no rework for the maximum gap criteria.
- 7. Root Cause i The root cause of this condition is the failure of the manufacturer to specify, maintain and inspect for adequate
- clearances between damper blade and frame during fabrication of the bubbletight dampers. Additionally, the manufacturer failed ,
to control seal materials as used on the original environmental qualification.
- 8. Transportability The only other bubbletight dampers used are "S" Class dampers which are located in the technical support center and emergency operating facility, and their potential failure does not constitute a safety hazard. Additional "S" Class bubbletight n dampers have been installed in the Unit 3 containment purge
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system and are scheduled to be installed in Units 1 and 2.
The damper drawings submitted' by Waldinger have been reviewed by Engineering and no other critical dimensions that could affect
. the operability and bubbletightness of the dampers were identified.
- 9. Analysis of Safety Implications
. An evaluation, was made (Reference 2) to estimate possible -
control room in-leakage, assuming all pressure boundary dampers developed some leakage due to torn seals. This evaluation was I performed assuming the essential ventilation system operating i and with the control room normal air handling unit shutdown. An analytical model of a defective damper seal was defined and corresponding control room out-leakages and in-leakages were estimated on an overall basis. Based on the evaluation, if defective seals are present, filtered outside makeup air could
- exceed the 1000 cfm design by approximately 20 percent.
However, a separate evaluation was performed (Reference 3) to show that even if the rate of makeup air was doubled (2000 cfm),
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the control room personnel dosage to thyroid, whole body and skin would not exceed the GDC-19 limits.
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The entrance of unfiltered outside air is only possible if the 1 normal air handling unit fails to de-energize on actuation of the emergency safety feature (ESF) units. _It should be noted that only one of the two dampers in-Unit 1 (U4-HJA-H01) which isolate the normal air handling unit discharge from essential -
HVAC was found with a tear. The second isolation damper !
- (IM-HJB-M01) did not have' any tears or small gaps which could cause a seal failure. Additionally, none of the Unit 2 or -3:
' discharge line dampers were found with torn seals or small gaps.- Since these dampers operate as a system, the continued operation of Units 1, 2 and 3 with the damper condition uncorrected, would not have created a significant' safety hazard.
In the evaluation of toxic chemical releases on control room 1
. operators, FSAR Section 2.2.3 assumed that the normal control room HVAC system continued to operate at 1200 cfm outside air makeup with no unacceptable consequences. No credit was taken for control room isolation to mitigate the effects of a toxic chemical release. . Thus, the potential leakage through torn 1 damper seals, if the control room was placed in the isolation mode, is enveloped by the current safety analysis. Therefore, l there is no safety concern regarding chemical releases.-
The auxiliary feedwater pump room isolation dampers, due to their physical location, will not become submerged and therefore-will not become a leak source to the adjacent pump room.
-(Reference 5).
The evaluation performed in Reference 2 also indicates that maximum airleaks for dampers 1, 2, and 3M-HJB-H67, will not significantly reduce halon _ concentration in the computer room and will maintain the required minimum concentration of.five percent for 10 minutes.
II. . REPORTABILITY ASSESSMENT Based on the above, this condition is evaluated as not reportable under
-10CFR Part 50.55(e) and Part 21 since, if this condition were to remain uncorrected, it would not represent a significant safety condition.
III. CORRECTIVE ACTION A. Unit 3
- 1. General
- a. The manufacturer (Ruskin) has provided new blade seal installation instructions for use by ANPP (Reference 8).
References 4 and 9 provide specific instructions on correct blade end to housing clearances 'both for undersized and oversized gaps to prevent seal tearing during cycling while maintaining leak tight integrity.
.b. Ruskin has taken necessary measures to correct and control their purchase order documentation program so that the proper seal: material is _ supplied for any future orders.
c.. All (25) dampers listed below have been inspected and those that have blade clearances outside the range of the prototype dampers, seal damage, and incorrect seal-materials have been reworked. The criteria for rework is the accepted dimensions established by the. environmental qualification test as shown in Table 1 for small gap clearances and reference 4 for the oversize gaps. The damper numbers and corresponding work order or. inspection documents generated to perform this task are'as follows:
Damper No. NQL Damper No. SWA 3M-HJB-M55 SM-6531 3M-HJA-H01' 10391 3M-HJA-M52 SM-6531 3M-HJB-M01 10391 MJ-3165' 3M-IIJB-M13 10391-3M-HJB-M57 MJ-3108 3M-HJA-M59 10391 MJ-3086 3M-HJB-M10 10391 13M-HJA-M57 SM-6531 ~3M-HJA-M58 10391 3M-HJB-M56 SM-6531 3M-HJB-M67 SM-6531' 3M-HJA4156 SM-6531
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3M-HJA-M02 SM-6531 31-HJB4102 SM-6531 31-HJA4103 SM-6531 3H-HJB-H03 SM-6628 3M-HJA-M15 SM-6628 3M-HJA-M16 SM-6628 3M-HJB-M23 SM-6628 3M-HJE-M24 SM-6628 3M-HAA4f214 SM-6628 3M-HAB-M215 SM-6628 3M-HAA4f216 SM-6628 3M-IIAB-M217 SM-6628 B. Units 1 and 2
- 1. 48-inch Diameter
- a. The four 48-inch diameter dampers for Unit 1 (1M-HJA-M01, IM-HJB-H01, IM-HJA-M52, IM-HJB4155) have been inspected and those that have blade clearances outside the range of the acceptance criteria as identified in Table 1 for the minimum gap and Reference 1 for the maximum gap and sharp edges or burrs have been reworked under contractor work order (CWO) No. 177886. Also, the silicone seal of the
-four 48-inch diameter dampers has been replaced.
- b. The four 48-inch diameter dampers for Unit 2 (2M-HJA-M01,-
2M-HJB-M01, 2M-HJA4152, 2M-HJB-M55) have been inspected and those that have blade clearance outside the range of the acceptance criteria as identified in Table 1 for the minimum gap and Reference 1 for. the maximum gap have been reworked under contractor work order (CWO) No. 178952.
. Also,' the silicone seal of < the four 48-inch diameter dampers has been replaced.
- 2. Control room pressurization surveillance test 73ST-9HJ01 has been' performed in Units 1 and 2 to show the ability of the remaining control room pressure boundary dampers to maintain 1/8-inch water gauge pressure inside the control room at a makeup rate of less than.1000 cfm.
~ 3. - Since testing by Ruskin Manufacturing Company has shown that 30-inch and smaller diameter dampers are less susceptible to seal damage in the presence of small gaps and, because the remaining control room isolation dampers provide an out-leakage flow path from the control room and finally, because the Unit 3 inspection did not identify any significant seal failure, the following inspection program will be impicuented:
- a. Dampers 1M-HJA-M57, IM-HJB4157, will be inspected and reworked, as necessary, at the first refueling outage.
- b. Dampors 2M-HJA-M57, 2M-HJB-M57, will be inspected and reworked, as necessary, at the first major outage.
- c. Damper 2M-HJB-M67 (30-inch diameter) which has a 50 durometer seal material will be inspected and reworked, as necessary, at the first major outage.
- d. Dampers IM-HJA4159.and IM-HJB-M13 which could have a potential for.inleakage of smoke to the control room from the inverter / communications' room'will be inspected and reworked, as necessary, at the first-refuellag outage.
- e. Dampers 2M-HJA4159 and 2M-HJB-M13 which could be the potential for inleakage for smoke to the control room from the inverter / communications room will be ' inspected and reworked, if necessary, at the first major outage.
- 4. Although the inspection of Unit 3 smaller than 30-inch diameter dampers did not identify any significant seal failure problems with the dampers, the following inspection program will be implemented to ensure that the tolerance criteria as identified in reference 4 is met.
- a. The computer room isolation damper IM-HJB-M67 will be inspected and reworked as necessary at the end of the seal qualified life.
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b.- The auxiliary feedwater pump room isolation dampers (1M-HAA-M214, IM-HAB-M215, IM-HAA-M216, IM-HAB-M217,
-2M-HAA-M214, 2M-HAB-H215, 2M-HAA-M216 and 2M-HAB-M217) will be inspected and reworked, as necessary, at the end of their qualified life.
C. Interim Accelerated Surveillance Testing in Units 1 and 2:
In order to ensure that control room-pressure integrity is maintained, the following accelerated surveillance testing will be implemented until such time that the remainder of tto control room pressure boundary dampers in each unit are inspected and reworked as necessary. The remainder of the control room pressure boundary dampers are shown in Table 3.
- l. . Perform surveillance test 73ST-9HJ01 on a semi-annual basis.
- 2. If the control room pressure margin is between 50% and 25% of the margin observed at the end of the 48-inch diameter damper inspection / rework program, then perform surveillance test 73ST-9HJ01 on a quarterly basis until such time that the dampers are inspected and reworked, as necessary, to obtain a greater than 50% pressure margin.
- 3. If the control room pressure margin is less than 25% of the margin observed at the end of the inspection / rework program of 4-the 48-inch diameter dampers, then perform surveillance test 73ST-9EJ01 on a monthly basis until such time that the dampers are inspected and reworked, as necessary, to obtain a greater than 50% pressure margin. The control room pressurization testing 73ST-9HJ01 will resume the normal 18-month performance schedule when all the pressure boundary dampers are inspected.
D. Technical Support Center (TSC) and Emergency Operations Facility (EOF) bubbletight dampers:
There are 3 bubbletight dampers in TSC and EOF HVAC Systems (two in TSC, one in EOF). Since these dampers are not quality related (Q Class), an evaluation for safety significance was not performed.
However, the function of these dampers is similiar to the dampers in the control building HVAC system. Hence, an Engineering Evaluation Request (EER) No. 86-HN-01) has been written to investigate and provide corrective action, as necessary, for the TSC and EOF bubbletight dampers.
-4 5 IV. References
- 1. Document No. M598-4485, Bubbletight Damper; procedure for aged seals and maximum / minimum blade gaps.
. 2. Calculation No.13-MC-HJ-803, Bubbletight Isolation Damper leakage due to seal failure.
'3. ANPP letter, ANPM-28714-ACR/JRM-98.36 dated October 28, 1986.
- 4. Document No. M598-4564, Bubbletight Damper Blade Seal and Blade Gap
~Evaluatlon.
- 5. Calculation No.13-MC-ZA-808, Main Steam Support Structure (MSSS)
-Building Flooding @ evaluation 81'-0".
- 6. Document No. M598-4567, Tensile Hardness and Tear Test for seals from dampers 3M-HJB-M57 and 3M-HJB-H67.
- 7. Waldinger letter, F-TWC-BCI-86-186, dated June 13, 1986.
- 8. Document No..M598-1850, Instruction and Operation Manual for Isolation Dampers.
- 9. Document No. M598-4480, Bubbletight Damper Review and Walkdown.
- 10. Document Nos. M598-1117, M598-1712, 1713 and 1714, Environmental and Seismic Qualification for Damper Assemblies and Actuators.
4 4
1
- - - . . - - _ , _ . . . . . . ~ _ . , - _ _ . . ~ . . _ _ - . _ _ _ _ , _ - - . . _ . _ . _ _ _ _ . . . . _ _ - . , _ - . . _ . . . - _ . _ _
1 DER 86-20 Final R; port 1 -
- . ~
TABLE 1 BLADE TO FRAME GAP DIMENSIONS FOR Q CLASS BUBBLETIGHT DAMPERS IN UNIT 3 l l l Max l Max l Min 1 Min l l l Damper Tag No. l Size l Field l Seismic /Envirn. l Field l Seismic /Envira. l Remarks! l j l l l Gap l Sample Gap l Gap l Sample Gap l 'l1
! l l l l 1 l l l l 3M-lUB-M55 l l 0.281 (9/32") l l 0.047 (3/64") l . l 'l l 3M-lUA-M01 l 48" dia. l 0.328 (21/64") l 0.250" (1/4") l 0.094 (3/32") l 0.094" (3/32") l See Note 1 l '
l 3M-IUB-l!01 l l 0.328 (21/64") l l 0.125 (1/8") l l l-l l 3M-lUA-M52 l l .437 (7/16") l l 0.125 (1/8") l l l 1
l 3M-luB-M57 l 40" dia. l 0.250 (1/4") l 0.281" (9/32") l 0.062 (1/16") l 0.172" (11/64") l See Note 1 l l 3M-lUA4157 l l 0.281 (9/32") l l 0.047 (3/64") l l l
- l 3M-IUB-M56 l l 0.266 (17/64") l l 0.094 (3/32") l l l
! l 3M-HJB-M67 l 30" dia. l 0.250 (1/4") l 0.218" (7/32") l 0.125 (1/8") l'O.078" (5/64") l See Note 1 l l l 3M-IUA-M56 l l 0.250 (1/4") l l 0.094 (3/32") l l l
{ l 3M-luB4113 1 18" dia. l +1/8* l 0.250"-(1/4") l +1/8* I 0.125" (1/8") l See Note 3 l l
l 3M-lUA4!59 l l 0.250 (1/4") l See Note 4 l 0.125 (1/8") l See Note 4 l See Note 1 l l 3M-1UB4110 1 16" dia. 1 0.234 (15/64") l 0.250" (1/4") l 0.125 (1/8") l 0.125" (1/8") l See Note 1 l j l 3M-lUA-1158 l l 0.250 (1/4") l See Note 4 l 0.125 (1/8") l See Note 4 l l 3M-lUA4102 l l 0.250 (1/4") l I 0.125 (1/8") 1. l l l 3M-lUB-M02 l 14" dia. l 0.250 (1/4") l 0.250" (1/4") l 0.125 (1/8") .I 0.125" (1/8") l See Notes l'and 2 l t l 3M-lUA-M03 l l 0.250 (1/4") l l 0.125 (1/8") l l l j l 3M-IUB-M03 l l 0.297 (19/64") l l 0.109 (7/64") l l l' l 3M-lUA-M16 l 12" dia. l 0.234 (15/64") 1 0.250" (1/4") l 0.140 (9/64") l 0.125" (1/8") lSee Note 1- l l 3M-IUB-M24 l 12" dia. l 0.219 (7/32") l l 0.109 (7/64") l l l j l 3M-IIAA-M214 l l 0.156 (5/32") l l 0.109 (7/64") l l l' '
! l 3M-HAA41216 l l 0.188 (3/16") l l 0.125 (1/8") l l l j l 3M-HAB41215 l 10" dia. l 0.188 (3/16") l 0.250" (1/4") l 0.140 (9/64") l 0.125" (1/8") l l
, l 3M-IIAB-M217 l l 0.203 (13/64") l See Note 4 l 0.125 (1/8") l See Note 4 l See Note 1 l .
j l 3M-lUA-M15 l l 0.265 (17/64") l l 0.109 (7/64") l l l j l 3M-1UB-M23 l l 0.234 (15/64") l l 0.140 (9/64") l l l Nstes: (1) Mapped and cycled per H598-4480 (Reference 9).
(2) IMA-If02 and IUA-M03 were verified to be > 1/8" gap per NCR SM-6531.
l (3) Previously inspected by TWC/Ruskin accepted by BCI Engineering (no map required). Dampers cycled.
! (4) Seismic qualification performed only on 48", 40", 30", 14" and 12" dampers (Ref. 10). Minimum '
gap of 1/8" and maximum gap of 1/4" were selected since 10",16", and 18" dia:neter dampers are j similar in design and construction to 12" and 14" diameter dampers.
- Caps visually measured.
9264Q
TABLE 2
- BLADE TO FRAME GAP FOR' UNITS 1 AND 2 48 INCH DIAMETER DAMPERS UNIT ' 1 l l MAXIMUM l MINIMUM .I l l DAMPER NO.'l- FIELD-GAP l FIELD' GAP l REMARKS l l l _ l l1/2".& 1-3/4" Seal l l1-M-HJA-M01 l 23/64 Inch l 3/16 -Inch l Tear Found l l l- l l Retaining l l1-M-HJB-M01 l 25/64 Inch l -7/16 Inch l Ring Replaced l l l l l l l1-M-HJA-M52 5/16 -Inch l 11/64 Inch l l
.l ,
I l l l1-M-HJB-M55 l 5/16 Inch I. 5/32- Inch l l, UNIT 2 l l MAXIMUM l MINIMUM l l DAMPER NO. FIELD GAP FIELD GAP REMARKS
- l. l l2-M-HJA-M01 l- 17/64 Inch l 7/64 Inch l l l i= l l l l2-M-HJB-M01 9/32 Inc h 1/8 Inc h l l . l l l --
l2-M-HJA-M52 l 17/64 Inch l 7/64 Inch l l l l l l 17-1/2" Seal l l2-M-HJB-M55 l 17/64 Inch- l Gap 3/32 Inch l Tear Found l L
ca - _
1 TABLE 3 +
REMAINDER OF CONTROL' ROOM PRESSURE BOUNDARY DAMPERS TO BE INSPECTED UNIT 1 ,
l- 1 I I DAMPER NO. SIZE -FUNCIlON 'l l l ,
l l IM-HJA-H57 l 40 Inch l Smoke Exhaust Isolation l
! 1M-HJB-M57 40 Inch Smoke Exhaust Isolation l IM-HJA-M56 30 Inch Smoke Purge Isolation
-l IM-HJB-M56 30 Inch Smoke Purge Isolationa
.l 1M-HJA-M13 - 18 Inch Inverter Room Return Air Isolation l '
l 1M-HJA-M59 18 Inch Inverter Room Return ' Air Isolation l l IM-HJB-M10 18 Inch Inverter Room $upply Isolation l l- IM-HJA-M58 18 Inch l Inverter Room Supply Isolation l l IM-HJA-M02 .14 Inch -Make Up Air Isolation to Train A l.
l 1M-HJB-M02 ' l' 14 Inch .
Make Up Air. Isolation to Train A l 1M-HJA'M03 l 14 Inch ll Make Up Air Isolation to Train B l
.IM-HJB-M03- 14 Inch > Make Up Air. Isolation to Train B l l 1M-HJA-M16 12 Inch Kitchen Exhaust Isolation l l 1M-HJB-M24 12 Inch Kitchen Exhaust Isq1ation l l 1M-HJA-15 i 10 Inch , Toilet Exhaust Isolation l l 1M-HJB-23 -l 10 Inch l Toilet Exhaust Isolation l *i UNIT 2 r
l 1- 1 I l DAMPER NO. SIZE FUNCTION l 40 Inch i 2M-HJA-H57 Saoke-Exhaust, Isolation l_ 2M-HJB-M57 40 Inch l Smoke Exhaust Isolation l l 2M-HJA-M56 30 Inch l Smoke Purge Isolation l .;
2M-HJB-M56 30 Inch Smoke Purge Isolation' l 2M-HJA-M13 18 Inch l Inverter Room Return Air IsolatioiIl (' i l 2M-IlJA-M59 18 Inch l Inverter Room Return Air Isolation l .y 1 l 2H-HJB-M10 18 Inch o Inverter Room Supply Isolation l 18 Inch X1 l 2M-HJA-M58 Inierter Room Supply Isolation l
l 2M-HJA-M02 i 14 Inch Make Up Air Isolation to Train A l 2M-HJB-M02 .I 14 Inch H Hake Up Air Isolation.to Train A l Make Up Air Isolation to Train B l 2M-HJA-M03 l 14 Inch l 2M-HJB-M03 l 14 Inch Make Up Air Isolation to Train B '
2M-HJA-M16 i 12 Inch Kitchen Exhaust Isolation l 2M-HJB-M24 l 12 Inch l Kitchen Exhaust Isolation l 2M-HJA-15 l 10 Inch l Toilet Exhaust Isolation l l 2M-HJB-23 l 10 Inch l Toilet Exhaust Isolation l
/