ML20235G944
| ML20235G944 | |
| Person / Time | |
|---|---|
| Site: | Sequoyah  |
| Issue date: | 07/02/1987 |
| From: | Gridley R TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM) |
| Shared Package | |
| ML20235G946 | List: |
| References | |
| NUDOCS 8707140435 | |
| Download: ML20235G944 (10) | |
Text
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TENNESSEE VALLEY AUTHORITY CHATTANOOGA. TENNESSEE 374o1 SN 157B Lookout Place JUL 0 2 887 1
U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C.
20555 Gentlemen:
In the Matter of
)
Docket Nos. 50-327 Tennessee Valley Authority
)
50-328 SEQUOYAH NUCLEAR PLANT (SQN) - INSERVICE TEST (IST) PROCRAM To support NRC preparation of a revised safety evaluation report (SER) for SQN's IST Prograc., TVA provided 13 items for resolution in a November 17, 1986 submittal and three additional relief requests in a December 12, 1986 submittal. A subsequent conference call betw?en TVA and NRC reviewers on February 2, 1987, helped to establish mutual NRC-TVA position regarding these unresolved items and relief requests.
As a result of this conference call.
TVA is providing this updated status of SQN's IST Program.
This submittal contains:
1 1.
A commitment for including the charging line and reactor coolant pump (RCP) seal injection check valves into SQN's IST Program (reference November 1986 cubmittal; items 6 and 7).
2.
Additional details from SQN's Surveillance Instruction (SI) 166.4 to support the relief request for postaccident sampling valves (reference November 1986 submittal; item 10).
3.
A request to disassemble and inspect eight low head safety injection l
(LHSI) check valves (reference November 1986 submittal; item 12).
4.
Additional information to support SQN's relief request concerning the accuracy and range of specific test equipment (reference December 1986 submittal; item 3).
5.
Five additional relief requests to SQN's IST Program.
A thorough description of items 1-4 above is included as enclosure 1.
The five new relief requests are included as encJosure 2.
It is requested that this submittal be expediently reviewed se that the forthcoming revised SER may reflect these changes. Those items that constitute startup requirements have 8707140435 870702 PDR ADOCK 05000327 P
PDR g
An Equal Opportunity Employer k_
.g.
U.S. Nuclear Regulatory Commission JU[ Q 2 j@@7 been labeled with (SU) in both enclosures.
If this additional information and j
relief requests significantly hinder NRC's preparation of a revised SER, a written response documenting NRC review and concurrence with SQN's pump and valve program would be beneficiel for SQN restart. Upon receipt of uither a revised SER or NRC concurrence, SQN will change its pump and valve program to i
be consistent with NRC's approved position.
Very truly yours, TENNESSEE VALLEY AUTHORITY R.
ri ey, D rector Nuclear Safet and Licensing Enclosures cc (Enclosures):
Mr. G. G. Zech, Assistant Director for Inspection Programs Office of Special Projects U.S. Nuclear Regulatory Commission j
101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 l
Mr. J. A. Zwolinski, Assistant Director for Projects Division of TVA Projects Office of Special Projects U.S. Nuclear Regulatory Commission 4350 East West Highway EWW 322 Bethesda, Maryland 20814 Sequoyah Resident Inspector Sequoyah Nuclear Plant 1
2600 Igou Ferry Road I
Soddy Daisy, Tennessee 37379 l
i 1
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j l
ENCLOSURE 1 1.
Inclusion of normal charging line check valve 62-543 and RCP seal injection check valves62-560, -561, -562, and -563 to SQN's IST Program.
Previous TVA Position TVA provided justification for not including these check valves to SQN's IST Program in a November 1986 submittal (items 6 and 7).
TVA's position was that these valves (although designated as inboard containment isolation valves in accordancu with 10 CFR 50, GDC 55) are not type C leak tested in accordance with Appendix J.
This is due to the 30-day water seal that is provided postaccident by the centrifugal charging pumps (CCPs) at a pressure greater than 1.1 Pa.
The 30-day water seal inventory is provided by recirculation from the containment sump. This water seal precludes a release path, preventing any leakige of containment atmosphere through the penetration to the environment. The water seal is ensured since at least one CCP will always remain in service postaccident even with consideration of a single active failure.
NRC Position Following NRC review of TVA's submittal, Jim Pulsifer (NRC reviewer) stated during a conference call on February 2,1987, that a break occurring outside containment would result in'a reversal of flow and subsequently preclude a water seni. TVA agreed that the subject check valves act as inboard containment isolation barriers and would be required to go closed upon a reversal of flow. TVA agreed that these valves be added to SQN's IST Program and that a closure test be performed periodically.
TVA Position - Relief Request SQN intends to add the subject valvos to its IST Program.
The single charging line check valve will receive a closure test each cold shutdown (CSD) not to exceed once each quarter.
Quarterly l
exercising this valve during plant operation is not practical since performance of the closure test requires isolation of the normal charging path. CSD testing meets the IWV-3522 requirement when testing during operation is not practical.
Because of the abnormal system alignment required to test the four seal injection check valves. SQN requests relief from the IWV-3521 and IWV-3522 requirements.
In lieu of the IWV-3521 and IWV-3522 quarterly (during operation /during CSD) test requirements, SQN requests relief to perform a closure test on the four seal injection check valves every refueling outage. A test of these valves requires the reactor coolant system (RCS) level to be drained down below the level of the RCP seals, which is normally only done during refueling outages while in mode 6.
It is apparent that testinr, during operation is not possible.
SQN, in accordance with 10 CFR 50.55a(a)(3), believes that the IWV-3522
(
requirement to test those valves each CSD results in " hardship and unusual difficulty without a compensating increase in the level of quality and safety." For these reasons, SQN requests code exemption to test the four seal injection check valves each refueling outage.
2.
Additional details to support pending relief request for (SU) postaccident sampling (PAS) valves FSV-43-250, -251, -287, -288. -307,
-309, -310, ~317, -313. -319, -325, and -341.
TVA's Basis For Relief TVA provided in item 10 of the November 1986 submittal the justification for relief from the IWV-3300 code requirement for the subject PAS valves.
TVA's basis for relief was that visual confirmation of valve position as required by the code was not possible due to the totally enclosed design of these Target Rock Company solenoid valves.
To meet the intent of the code, SQN provided an alternate test method using system pressure to serve in lieu of visual confirmation.
Specific details of the test were not provided in the November 1986 submittal since the test instruction SI-166.4, " Remote Valve Position Indication During Refueling Outage," was under the plant review process for approval.
NRC Position NRC requested in a February 1987 conference call that SQN provide a copy of the plant-approved instruction SI-166.4 for NRC review.
This instruction would provide the necessary details to support NRC approval of SQN's relief request.
Conclusion A copy of the plant-approved instruction SI-166.4 and a simplified diagram of the PAS system are provided as an attachment to enclosure 1.
3.
Addition of eight LHSI check valves for disassembly and inspection each j
refueling on a rotating basis.
(Four cold-leg residual heat removal (RHR) secondary check valves--63-632, -633, -634, and -635; and four hot-leg RHR primary and secondary check valves--63-640
-641. -643, and
-644).
TVA Basis For Relief I
TVA provided in item 12 of the November 1986 submittal a statement of position / current testing / philosophy with regard to the full stroking of j
check valves arranged in parallel. SQN indicated that the LHSI check valves could not be individually verified to full stroke (they are arranged in parallel combinations of two) but " reasonable assurance" is provided that they do and can function as required under alternate test l
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. _ _ _ - _ _ _. ___ _ - - __ -__ - _ - _ _ methods.
SQN requested an alternate test method involving verification of the required total injection flow.
- a. Verification of flow greater that 1,988 gal / min through each cold-leg injection line on a cold shutdown basis (nine months).
- b. Verification of flow greater than 500 gal / min through the hot-leg injection line on a cold shutdown basis (nine months).
NRC Position NRC's position is that SQN's alternate test proposal for the LH5I check valves does not meet the intent of the code and does not provide reasonable assurance that each LHSI check valve receives full-stroke testing.
Conclusion Based on present NRC position and in lieu of the alternate test methods described above SQN is modifying the November 1986 proposal to include disassembly and inspection of one cold-leg LHSI check valve and one hot-les LHSI check valve each refueling outage on a rotating basis.
This will ensure that the full-stroke requirements delineated in IWV-3522 are met.
The alternate test method described above will remain in SQN's IST Program and will serve to satisfy the part-stroke requirements of IWV-3522.
4.
Additional information to support SQN's relief request concerning the (SU) accuracy and range of specific test equipment.
TVA Basis For Relief _
Item 3 of TVA's December 1906 submittal requested relief from the accuracy and range requirements for certain test equipment under certain applications. TVA stated that these code requirements (IWP-4120, 1977 Edition Summer 1978 Addenda, SQN unit 2; and IWP-4111,1974 Edition Summer 1975 Addenda, SQN unit'1) were found to be either impossible or impractical.
Examples given included:
a.
Boric acid transfer pumps (BATPs):
Low suction pressure reading imposes impractical range requirements on the suction pressure gauges.
b.
Vibration equipment, thermocouple, tachometers, and differential pressure transmitters: Standard scales within the equipment impose impractical and in some cases impossible range requirements.
NRC Position NRC finds the impracticality of SQN's relief request unclear with regard to accuracy and range. SQN also did not address why code requirements were impractical for thermocouple and tachometers in the examples provided in the December 1986 submittal, k
_ _ - _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ - Conclusion The following discussion is provided to clarify SQN's pending relief request with regard to the accuracy and range. Most of the discussion deals with the IWP-4120 range requirement ("the full scale range el each instrament shall be three times the reference value or less") and the IWP 4111 range requirement ("the fell scale range of each instrument shall be four tines the reference value or less"),
s.
Boric acid transfer pumps (BATPs)
SQN's BATPs characteristically operate under low suction pressure.
Suction pressures as low as 1.5 psig have been recorded.
In order to meet the 3 x 1.5-psig' range requirements of IWP-4120, a 4.5-psig full-scale pressure gauge would be required. This is an impractical requirement since specially made low-range pressure gauges are not normally commercially available. The same range impractically exists for the 4 x 1.5-psig range requirement of IWP-4111.
It was noted in the December 1986 submittal that the difference in accuracy between a commercial 15-psig gauge and the 4.5-psig gauge required by the code was negligible. The maximum allowable error for the 4.5-psig gauge is two percent of full scale or 0.09 psig. The maximum allowable error for the 15-psig gauge is two porcent of full scale or 0.30 psis. This results in a difference in accuracy between the two gauges of only 0.21 psig; SQN continuss to support the relief requested in the December 1986 submittal to use a 15-psig suction gauge for the BATPs.
b.
Vibration equipment SQN utilizes digital and analog vibration measuring equipment manufactured by Bentley-Nevada, Palomar Technology International, and 1
IRD Corporation that has normal standard scales of 0-100 mils for the digital equipment and 0-0.03, 0-0.1, 0-0.3 0-1, 0-2, 0-3, 0-10, 3
0-30, and 0-100 mil scales for the analog equipment. For a vibration reading (reference value) of 3.1 mils, the IWP-4120 range requirement j
of three times the reference value (3 x 3.1 = 9.3) would not be
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possible with the available scales.
The 0-10 or 0-100 scales would exceed the 3K code requirement. The 4X code requirement of IWP-4111 (4 x 3.1 = 12.4) would, however, be met with the 0-10 scale.
Decause of the impractical 3X rcnge requirement, SQN continues to support the December 1986 relief request from IWP-4120 for vibration equipment.
c.
Digital temperature _ instruments SQN utilizes a portable digital temperature instrument manufactured j
by Fluke and the plant-installed Morgan Temperature Monitoring System I
located on panel M-10 in the control room. These instruments are used to measure bearing temperature on the safety injection pumps and CCPs. A single full-scale range spans from 0 to 9990 with no 0
intermediate scales. For a reading (reference value) of 150, the IWp-4120 range requirement of three times the reference value (3 x 50 = 450) and the IWP-4111 range requirement of four times the L
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reference value (4 at 150 = 600) would not be possible with the available scale. Because of the impractical range requirement of l
IWP-4120 and IWP-4111 for versatile, accurate, and commercially available equipment SQN continues to support the December 1986 i
relief request from IWP-4120 and IWP-4111 for digital temperature instruments, d.
Djzital tachometers SQN utilizes digital tachometers manufactured by Bentley-Novada (DVF-2) and Spectral Dynamics Corporation (DYKAC-119).
The scale ranges are built into the test equipment. The Bentley-Nevada, for example, is provided with a scale of 0-9,999 r/ min with no intermediate scales.
'A reading (reference value) of 1,800 r/ min would limit the maximum full-scale range to 5,400 r/ min under the 3X INP-4120 requirement and 7,200 r/cin under the 4K IWP-4111 requirement.
It becomes apparent that a 0-9,999-r/ min scale would not meet the full-scale range required under IWP-4111 or IWP-4120.
Because of the impractical range requirements of IWP-4120 and IWP-4111, SQN requests relief from these two code requirements for digital tachometers.
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e.
Differential pressure transmitters In the December 1986 submittal (item 3), SQN provided a discussion of I
the impracticalities involving accuracy and range requirements as they apply to differential pressure transmitters. At that time, SQN's Mechanical Test Section was considering the use of Valedine i
differential pressure transmitters for measuring differential pressure across the essential raw cooling water (ERCW) pumps.
The Valedine transmitter being considered had a range of 0-125 inches of water, which would not meet the IWP-4111 requirement.
Since that time, SQN has decided to measure ERCW differential pressure using differential pressure cells with ranges that comply with the code.
Should the need arise for using differential pressure transmitters, SQN has learned that Rotemount manufactures a differential pressure transmitter that meets tue necessary code requirements for range.
SQN, therefore, findt it unnecessary at this time to request relief from the IWP-4120 o't IWP-4111 requirements for differential pressure transmitters.
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L.
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Attachment POST ACCIDENT SAMPLING SYSTEM (Liquid Sampling)
NOTE: REFER TO PART B 0F THE APPLICABLE SI-166 VALVE DATA SHEETS FOR i*
, INSTRUCTION STEPS.
f.9po.3fo 3o1 3
P4 M C
(J A
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--HR TRAIN 1 ----# : M C
O 3i
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(1) CWT /lMNT ISxJTIW v
v VALYES
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FSV-43 252. ){~34 -270+c)( <-c)( +c)(
0 ae,4758
-3n 8
FAS COLLECTOR VAtveS ORAIN D
TANK U
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SAMPLE i
CHILLER NL 1 J
- : : : :S j
v
+
VN VN RC-V-3 43-2ti?
f RC-y-4 gj RC-V RC-Y RC-V NC-V KrY y.
-1.1 -1.2 -1. 3 -1. 4 -1.6 g3 vm
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r 43-256 RC-V-2 7
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MEL 2 0
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RC-y-7
- -C RC-y-S.1){RC-V-5.2){
g,,, y,7,g B M TTE (3); C3 (3) C n
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y RC-V-6.1}{ RC-V-6.fl
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l FILTER 12 SAME FLASX
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IM #1
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RC-8.1 RCS RC-V B.2 eness a t-FLASK DILUTED
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SAME Yg:.y.jg ggc.y.g RC-Y-22 ^
N 0FFGAS g
I-2 I (CONTINUED SE 2.3.3) w q
"I#
MGASSIFIER vv RC-V-19 CAP MILUTED SAME NOTE.t (1) IIGIM CWTAIM'NT SE FOLLOWING PAGE FW VALVE INNTIFICATION (2) 00TSIM CONTAIMNT SE FOLLOWING PAGE FW VALVE IDENTIFICATI04 (3) GUICK DISCMECT L
POST ACCIDENT SAMPLING SYSTEM
- )','
(Drainage)
NOTE:
REFER TO PART B 0F THE APPLICA3LE SI-166 VALVE DATA SHEETS FOR 1NSTkUCTION STEPS.
FA0V NIMOGEN StJFLY f43-456 L
s=e BE)K Ahr)
CAL TAhK 4 ~#52 in4XN486' 4D
/%
43-446 HVAC &
>4 LSf* APG CAP YASTE a 43-43B r-LT t
1 I
POST Af.CTDENT SAMPLING COLLNCIObDRAINTANK I
s' g
~
S GAL TAhK
\\
FSV-43-316
\\
FSV-43-325 FSV-43-317e k-M T
Q
) TO CtWTATIOGli St#P FSV-43-341 v 1
a 43-438 anENS AT k 15 PSI i L.'
.Jg T'
POST ACCIDENT SAMPLING SYSTEM (Containment Air Sampling;)
l NOTE; REFER TO FART B 0F THE APPLICABLE SI-166 VALVE DATA SHEET.9 FOR INSTRUCTION STEPS.
INLET CUTLET
^
OPPER ;
- LOWER A
B 43-2B9l l43-319 s3,norx x<3-32s 43-287l l43-318 CONTAINMENT
?. V< 2 SV-5 FM-1 RC-V-1 & G.C.
X
. EDUCTON n
/sy-2.2 hsv-3.1 A v-i y xsv-2.s ysv-<.1 Tz TO
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^
LSP gy.g, g gy.3, g gy.4, g ggy.go CFFGAS (pc caca caca a
)
CASK CASK USK 2
3 4
INLET CUTLET PC-1 BYPASS X
J Ng X
X VOLUME S cc SAMPLE CASK -
-