ML20138E148
| ML20138E148 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 06/22/1993 |
| From: | Bibiasio A, Fresco A BROOKHAVEN NATIONAL LABORATORY |
| To: | Campbell P Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20137B842 | List: |
| References | |
| CON-FIN-L-2301, FOIA-96-485 TAC-M84563, NUDOCS 9307120167 | |
| Download: ML20138E148 (52) | |
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TABLE OF CONTENTS Abstract iii
1.0 INTRODUCTION
1 2.0 PUMP IST PROGRAM REUEF REQUESTS 2
2.1 Generic Pump Relief Requests..
2 2.2 Diesol Fuel Oil System.....................................
5 2.3 Charging System.........................................
8 2.4 Intake Cooling Water System................................
10 2.5 Containment Spray and Safety injection Systems..................
11 3.0 VALVE IST PROGRAM REUEF REQUESTS 15 3.1 Generic Valve Relief Requests...............................
15 3.2 Safety injection System....................................
16 3.3 Containment isolation Valves................................
27 3.4 Containment Spray System 31 3.5 Emergency Diesel Generator Air Etart System....................
32 3.6 Auxiliary Feedwater System.................................
34 3.7 Intake Cooling Water System.. i..........
36 4.0 IST PROGRAM RECOMMENDED ACTION ITEMS 37 5.0 REFEREN C ES.................................................
44 i
APPENDIX A A-1
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ABSTRACT This report presents the results of Brookhaven National Laboratory's evaluation of St. Lucie i
Plant Unit 2's ASME Section XI Pump and Valve inservice Testing Program relief requests.
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I St. Lu:la Unit 2-SE Tcb6 Summary et R llef Reque,sta 1
1 ReNetRequest TER Section XI Requirement EaS _.,;
Proposed Ahomate NRC Action
. No.
Sect.
Identification Method of Testing t
PR 1 2.1.1 IWP-3300, 4310 Measurement All pumps None.
Relief not required per of oumo bearino temperature 650.55a illif4)fiv).
PR-2 2.1.2 IWP-4120, Instrument range Various pumps Use portable instruments with Authorized in accordance y
reading accuracy of 5% for with $50.55a 1(a)(3)(i), with i
temperature orovisions.
PR-3 2.1.3 IWP-3100, 3400, Measurement All Pumps For pumps that are already in Relief not required per of inlet pressure prior to pump operation, do not stop the pump
$50.55a 1(f)(4)(iv).
startuo to measure static inlet pressure.
I PR-7 2.2.1 IWP-4600, flow rate Diesel Fuel Oil Transfer Calculate flowrate based on Authorized in accordance
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measurement Pumps changes in level over time.
with $bO.55a 1(a)(3)(i), with orovisions.
?
PR-8 2.3.1 IWP-3100, measurement of Boric Acid Makeup Calculate pump inlet and Authorized in accordance f
suction and differential pressure.
Pumps differential pressure based on with $50.55a 1(a)(3)(i), with tank level.
orovisions.
[
P R-11 2.4.1 IWP-3100, Measurement of Intake Cooling Water Calculate pump inlet and Authorized in accordance
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suction and AP.
Pumps differential pressure based on with $50.55a 1(a)(3)(i), with intake structure level.
orovisions.
PR-12 2.3.2 IWP-4520(b), Vibration Charging Pumps Use instruments with lower Interim relief granted in j
instrument frequency response frequency response of 10 Hz.
accordance with $50.55a range.
1(t)(6)(i). for one year or until the next refueling i
outaae. whichever is later.
i PR-13 2.4.2 IWP-4520(b), Vibration intake Cooling Water Use instruments with lower Interim relief granted in f
instrument frequency response.
Pumps frequency response of 10 Hz.
accordance with $50.55a range.
1(f)(6)(i) for one year or until the next refusling catsoe. whichever is later.
t PR-14 2.5.2 IWP-4520(b), Vibration CS Hydrazine Pumps Use instruments with lower
- nterim relief granted in i
instrument frequency response frequency response of 10 Hz.
accordance with $50.55a range.
1(f)(6)(i) for one year or until the next refueling m_daa=. whk.b;r is later, j
PR-15 2.5.1 IWP-3100, Measurement of Containment Spray and Calculate pump inlet and Authonzed in accordance i
suction and AP.
Safety injection Pumps differential pressure based on with $50.55a 1(a)(3)(i), with tank level.
nrovisions.
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O t. Luzia Unit 2-SE Tchte 1-Cum.
/ cf Rollef Request 3 (Continued) l Relief Request TER Section XI Requirement Equipment Proposed Ahomete '
NRC Acton No.
. Sect.
Identification'-
Method of Teeung
~
PR-16 2.2.2 IWP-3100, Measuremord of Diesel Fuel Oil Transfer Calculate pump inlet and Authonzed in accordance suchon and AP.
Pumps differential pressure based on with $50.55a 1(a)(3)(i),
tank !:;;:.
,;;. orovis;oas.
PR-17 2.5.3 IWP-3200, 3300, 4150, CS Hydrazine Pumps Measure vibration only interim relief granted, with Measurement of flowrate quarterly, and flowrate and provisions, in accordance j
quarterly and associated vibration at refueling outages.
with $50.55a 1(f)(6)(i) for
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corrective actions.
one year or until the next refueling outage, whichever is later.
VR-1 3.1.1 IWV-3412, 4315, 3522, All cold shutdown Test in accordance with OMa-Relief not required per
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exercise all cold shutdown valves 1988, Part 10,14.2.1.2 and 950.55a 1(f)(4)(iv).
frequency valves each cold 4.3.2.2.
shutdown.
j VR-2 3.2.1 IWV-3427(b), valve acceptance V-3217, 3227, 3237, Use requirements in Technical Relief not required per i
i criteria for valves greater than 3247, 3258, 3259, Specification for PlVs
$50.55a 1(t)(4)(iv).
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6NPS.
3260, 3261, 3215,
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3225, 3235, 3245, t
3524, 3525, 3526, t
3527, Safety injection pressure isolation j
valves VR-4 3.3.;
IWV-3426 and 3427 Various CIVs Leak test groups of valves.
Relief not required per Measurement of individual valves'
$50.55a 1(f)(4)(iv).
seat leakaae.
i VR-13 3.2.2 IWV-3520, test frequency V-3215, 3225, 3235, Disassemble and inspect each Relief from exercising open i
3245, SIT to Si header valve once overy 10 years.
granted in accordance with check valves Exercise closed per Technical Generic Letter 89-04, i
Specification on PlVs.
Position 1 or 2 with i
provisions. Relief from exercising close1 not required j
per $50.55a 1(f)(4)(iv),
F provided all related i
reauirempets are met.
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St. Lurla Unit 2-CE Tchie 1-Cumi
, cf R;llef Request 3 (Continued)
Reef Request TER Section XI Requirernent Equipment Proposed Algemele NRC AcIlen i
No.
Sect. -
Identification Method of Teeeng VR-14 3.2.3 IWV-3520, test frequency V-3217, 3227, 3237 Partial-stroke exercise at cold Relief from exercising open 3247, Safety injection shutdowns and refusimg outages.
granted in accordance with header to RCS check Disassemble and inspect each Generic Letter 89-04, valves valve once every 10 years.
Position 1 or 2, with Exercise closed at cold provisions. Relief from shutdowns per Technical exercising closed not Specificatian on PlVs.
roouired.
VR-17 IWV-3520, test frequency V-6792, Nitrogen Verify valve closure at cold Relief not required.
sucolv CIV shutdowns.
VR-18 3.3.2 IWV-3520, test frequency V-15328, Makeup water Verify valve closure every 2 Relief not required per supply CIV years in accordance with
$50.55a 1(f)(4)(iv), provided Appendix J.
all related requirements are met and valves are tested at each refuelino outaae.
VR-19 3.3.3 IWV-3520, test frequency V-18195, instrument Verify valve closure capability Relief not required per -
air CIV every 2 years by $50 App. J
$50.55a 1(f)(4)(iv), provided leak test.
all related requirements are met and valves are tested at each refuelino outaae.
VR-24 3.4.1 IWV-3520, test frequency V-07256, 07258, Full-stroke test at refueling Relief not required per Hydrazine pumps to CS outages.
$50.55a 1(f)(4)(iv), provided pump suction check all related requirements are valves met.
VR 25 IWV-3520, test frequency V-27101, 27102, Exercise closed every cold Relief not required.
Sampling system CIVs shutdown. Leak test once every 2 voars ner Anaandix J.
VR-26 3.5.1 IWV-3413(b), stroke time FCV-59-1A1 through Exercise monthly in conjunction Relief denied.
measurement 4A1, FCV-59-1B1 with EDG testing. Exercise every through 401, SE-59-3A 6 months by obsennng operation through 6A, and SE of each pair of air start motors.
3B through 6B; EDG Air start valves.
VR-29 3.2.4 IWV-3427(b), valve acceptance V-3480, 3481, 3651, Verify valve closure capability Relief not required per criteria for valves greater than 6 3652, S1 PlVs.
in accordance with Technical
$50.55a 1(f)(4)(iv).
nos.
M!st% on PlVs.
3
i St. 1.u:13 Unit 2-SE TEbla 1-Sum
/ cf R2llif Request 3 (Continued)
^
~
Rehof Request TER Section XI Requirement Equipment.
Proposed Allemale
~
- NRC Adlon No.
Sect.
Identification Method of Testing s
VR-30 IWV-3520, test frequency V-3102, 3103, HPSI Partial-stroke exercise open Rehef granted in accordance v
min. flow check valves.
quarterly. Back flow test at cold with Generic Letter 89-04, t
shutdowns Disassemble and Position 2.
mapect one valve each refueling outaae.
VR-33 3.6.1 IWV-3414(a), POVs acceptance SE-09-2, 3, 4, 5, FW Valves will not be
- trended for Relief not required per criteria solenoid valves alert testing" quarterly. Valves $50.55a 1(f)(4)(iv), provided will be declared inoperative if all related requirements are l
stroke times exceed the met.
i maximum allowed stroke time.
}
During cold shutdowns, if a valve exceeds its alert limit, it will be f
addressed orior to startuo.
l V R-34 3.7.1 IWV-3414(a), POVs acceptance TCV-14-4A and B, Valves will not be " trended for Relief not required per criteria intake cooling water to alert testing" quarterly. Valves $50.55a 1(f)(4)(iv), provided CCW HX temperature will be declared inoperative if all related requirements are control valves.
stroke times exceed the met.
maximum allowed stroke time.
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i Technical Evaluation Report i
Pump and Valve Inservice Testing Program i
St. Lucie Plant, Unit 2 1.0 -
INTRODUCTION f
Contamed herein is a technical evaluation of ASME Section XI pump and valve inservice testing j
(IST) program relief requests submitted by Florida Power and Light Company (FP&L) for its St.
Lucie Plant, Unit 2. The St. Lucie Plant, Unit 2, is a Combustion Engineering Pressurized Water 2
Reactor (PWR) that began commercial operation in August 1983.
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FP&L submitted Revision 2 of the initial Ten-Year interval inservice Testing Program on September i
15,1992. This program revision supersedes all previous submittals. The initial ten year interval l
S extends from August 8,1983 to August 8,1993. The licensee states that this program is based
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on the requirements of the 1980 Edition of the ASME Section XI Code, including the Winter 1980 l.
Addenda. Additionally, the licensee submitted two revised relief requests in a letter dated January j
13,1993.
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l In their Revision 2 submittal letter, FP&L has requested approval of their relief requests by June 1
30,1993. As directed by the NRC Technical Monitor, BNL performed a,1 evaluation of only those relief requests discussed in Attachment 1 of the September 15,1992 letter and in the January 13, j
1993 letter, in order to accommodate FP&L's request. A cursory review of the other relief requests and the program description was performed.
The NRC staff previously issued a Safety Evaluation on January 13,1986 for the initial interval IST Program submitted October 6,1983. A Safety Evaluation was then issued on October 2,1989 for
- Revision 0" submitted April 4,1988 (Letter L-88-158). Additional Safety Evaluations were issued i
December 5,1991 and April 16,1992 addressing the lack of pump flow instrumentation. The I
licensee has provided a " Record of Revisions" with Revision 2, which states that Revision 2 was l
Issued August 1,1992; Revision 1 on January 30,1987; and Revision 0 on August 8,1983. This 4
does not agree with the licensee's April 4,1988 submittal. For each interval, the licensee should l
maintain an accurate status of the relief requests including their revision and NRC approval.
Additionally, each relief request should be uniquely identified and the same numbering system i
l should be maintained throughout the interval, even if relief requests are deleted.
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For the current interval, only new or revised relief requests are required to be submitted and approved by the NRC. It was not apparent, based on the lack of a consistent relief request l
identification system, which requests were previously approved in the January 13,1986 and l
October 2,1989 Safety Evaluations and whether they were revised subsequently. Therefore, only l
those relief requests identified in Attachment 1 of the September 15,1992 letter and in the January 13,1993 letter were evaluated, as discussed above. A!! relief requests submitted with the l
next ten year interval update, however, will be reviewed and evaluated for consistency with the j
current NRC regulatory positions as relief requests are approved for one interval, and not for the i
. life of the plant.
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Title 10 of the Code of Federal Regulations, 550.55a 1(f) requires that inservice testing of ASME l
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Code Class 1,2, and 3 pumps and valves be performed in accordance with Section XI of the l
ASME Boiler and Pressure Vessel Code and applicable addenda, except where specific relief has been requested by the licensee and granted by the commission pursuant to $50.55a 1(a)(3)(i),
2 (a)(3)(ii), or (f)(6)(i). Section 50.55a 1(f)(4)(iv) provides that inservice testing of pumps and valves i
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a i
I may meet the requirements set forth in subsequent editions and addenda that are incorporated by l
reference in paragraph (b) of $50.55a, subject to the limitations and moddications listed, and subject to Commission approval. Relief is not required to utilize portions of OMa-1988 Parts 6 l
and 10, as modified in paragraph (b) of $50.55a, provided that all related requirements are met l
l and subject to Commission approval as recommended in this TER. The implementation of related 2
requirements is subject to NRC inspection.
j The review of the relief requests was performed utilizing the Standard Review Plan, Section 3.9.6; l
Generic Letter No. 8944, Guidance on Developing Acceptable Inservice Testing Programs;" and i
the Minutes of the Public Meeting on Generic Letter 8944, dated October 25,1989. The IST l
Prograrn requirements apply only to component (i.e., pumps and valves) testing and are not intended to provide a basis to change the licensee's current Technical Specifications for system test requirements.
i Section 2 of this report presents the twelve pump relief requests referenced in Attachment 1 of FP&L's September 15,1992 letter and in their January 13,1993 letter and Brookhaven National Laboratory's (BNL) evaluation. Similar information is presented in Section 3 for twelve relief I
requests for the valve testing program. Relief requests that are authorized by Generic Letter 8944 i
are not specifically evaluated in this Technical Evaluation Report. However, any anomalies l
}
associated with the relief requests are addressed in Section 4 of the report.
l Section 4 summarizes the recommended actions for the licensee resulting from the relief request
)
l evaluations. BNL recommends that the licensee resolve these items in accordance with the j
evaluations, conclusions, and guidelines presented in this report.
1 i
2.0 PUMP IST PROGRAM RELIEF REQUESTS i-In accordance with $50.55a, FP&L has submitted seventeen relief requests for pumps at the St.
Lucie Plant, Unit 2 which are subject to inservice testing under the requirements of ASME Section 1
l-XI. The twelve relief requests referenced in Attachment 1 of FP&L's September 15,1992, letter i
and in their January 13,1993, letter have been reviewed to verify their technical basis and i
determine their acceptability. The relief requests, along with the technical evaluation by BNL, are summarized below.
2.1 Generic Pump Relief Reauests 2.1.1 Pump Relief Request No. PR 1, All Pumps in the Inservice Test Program Relief Request: The licensee requests relief from the requirements of the ASME Code,Section XI, f lWP4300 and IWP-4310, which state that the temperature of all centrifugal pump bearings outside the main ~. low path and of the main shaft bearings of reciprocating pumps shall be measured at points selected to be respor.sive to changes in the temperature of the bearings.
Proposed Attemate Testing: None.
Licensee's Basis for Relief: The licensee states that: "A yearly bearing temperature measurement does not contribute to the monitoring of pump operational readiness during its service life.
Concems regarding extended pump runs while on mini-flow recirculation and ALARA concems
. outweigh any benefits obtained from one yearly temperature data point.
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The data associated with bearing temperatures taken at one-year intervals provides little statistical d
basis for determining the incremental degradation of a bearing or any meaningful trending informabon or correlation in many cases the pump bearings are water-cooled and thus, beanng temperature is a funcuon of the temperature of the cooling medium, which can vary considerably.
9 Vibration measurements are a significantly more reliable indication of pump bearing degradation than are temperature measurements. All pumps in the program are subjected to vibration measurements in accordance with IWP-4500. Although excessive bearing temperature is an l
indication of an imminent or existing bearing failure, it is highly unlikely that such a condition would go unnoticed during routine surveillance testing since it would manifest itself in other 4
j obvious indications such as audible noise, unusual vibration, increased motor current, etc. Any i
potential gain from taking bearing measurements, which in most cases would be done locally using portable instrumentation, cannot offset the cost in terms of dilution of operator effort, distraction of operators from other primary duties, excessive operating periods for standby pumps especially under minimum flow conditions, and unnecessary personnel radiation exposure. Based l
on the reasons similar to those set forth above, the ASME deleted the requirement for bearing
. temperature measurement in ASME OM Code, Subsection ISTB, the revised version of the Code for pump testing."
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Evaluadon: In rulemaking to 10CFR50.55a effective September 8,1992 (see Federal Rooister. Vol.
57, No.152, page 34666), the 1989 Edition of ASME Section XI was incorporated in paragraph (b) of 9 50.55a. The 1989 Edition provides that the rules for inservice testing of pumps are as i
j.
specified in ASBIE//NSI OMa-1988 Part 6. The staff imposed no limitations to OMa-1988 Part 6.
l Seebon 50.55a t'(f)(4)(iv) provides that inservice tests of pumps may meet the requirements set j
forth in subsequent editions and addenda that are incorporated by reference in paragraph (b) of f 50.55a, subject to the limitations and modifications listed, and subject to Commission approval.
Portions of editions or addenda m'ay be used provided that all related requirements of the respective editions or addenda are met.
Measurement of bearing temperatures is not required by ASME/ ANSI OMa 1988, Part 6, for inservice testing of pumps. Therefore, relief is not required, and the alternative is recommended j
for approval pursuant to $50.55a 1 (f)(4)(iv).
2.1.2 Pump Relief Request No. PR-2, Various Pumps
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Relief Requesf The licensee requests relief from the ASME Code,Section XI, ilWP 4120, which i
j requires that the full-scale range of each instrument shall be three times the reference value or less. This relief request applies to only portable instruments used for temperature and speed measurement. Many of the portable instruments used have digital readouts with multiple scales.
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i Proposed Altemate Tes#ng: Whenever portable instruments are used for measuring pump speed
. or bearing temperatures, the instruments will be such that the ' reading" accuracy is as follows:
Temperature 15 percent 3
Speed
- 2 percent Licensee's Basis for Relief: The licensee states:. ' Table IWP-4110-1 requires the accuracy oi instruments used to measure temperature and speed to be equal to or better than t5 percent for temperature and t2 percent for speed, both based on the full scale reading of the instrument.
This means that the accuracy of the measurement can vary as much as i15 percent and i6 percent, respectwely, assuming the range of the instruments extended to the allowed maximum.
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i These IST pump parameters are often measured with portable test instruments where commercially available instruments do not necessarily conform to the Code requirements for
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range. In these cases, high quality calibrated instruments will be used where the " reading'.
I accuracy is at least equal to the Code-requirement for full-scale accuracy. This will ensure that j
the measurements are always more accurate than the accuracy as determined by combining the j
requirements of Table IWP-4110-1 and Paragraph IWP 4120.*
4 in addition, the licensee states that: "These instruments are well within the accuracy requirements j
of the ASME Code, but cannot meet the upper scals limit of three times the reference values.'
Evalua#on: In pump relief request PR 1, the licensee requested relief from measuring pump i
bearing temperatures for all pumps in the Inservice Test Program. Therefore, the evaluation of j
PR-2 will only be concemed with pump speed.
q Section XI, Table IWP-4110-1 requires that speed instrumentation have an accuracy of 2% of full i
scale and f lWP-4120 requires that the full-scale range of each instrument be three times the reference value or less. This would result in a instrument reading accuracy of 6% of the reference value or less.
The NRC does not consider installation or replacement of instruments an undue burden, and l
compliance with later editions of the Code for instrumentation requirements is not a backfit.
i However, if instrumentation is available which meets the intent of the Code requirements for the j
actual reading, the use of such instrumentation provides an equivalent level of quality and safety i
for testing. When the range of e instrumer.t is greater than 3 times the reference value, but has an accuracy more conservative than ine Code, the combination of the range and accuracy provides a reading equivalent or better than the reading that would be achieved from -
j instrumentation which meets the Code requirements.
4 Therefore, based on the reading accuracy of the speed instruments meeting the accuracy j
1 requirements o."11WP-4110, it is recommended that the licensee's alternative testing be authorized in accordance w th 10 CFR 50.55a(a)(3)(i). When using temporary instruments, the licensee l
should ensure that the instruments are calibrated prior to use and are traceable to the inservice j-test records.
4 Pump Relief Request No. PR-3, All Pumps in the inservice Test
_2.1.3 Program i
i Relief Request: The licensee requests relief from the ASME Code, Section XI:
1.
11WP-3400, Frequency of Inservice Tests, which states that pumps which are operated more frequently than every 3 months need not be stopped for a special test, provided the plant log shows each such pump was operated at least once every 3 months at the reference conditions, and the quantities specified were measured, observed, recorded, and analyzed.
2.
Table IWP-3100-1 which states that each inservice test shall include the measurement and observation of pump inlet pressure, which shall be measured before pump startup and during the test.
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~ Proposed Atamate Tes#ng: When performing a test on a pump that is already in operation due to system or plant requirements, inlet pressure will only be measured during pump operation.
t Licensee's Basis for Re#ef: The licensee states thet: "If the pumps being tested are in operation f'
as a result of plant or system needs, it is unreasonable to reconfigure system lineup simply to j
provide for measurement of static inlet pressure. Inlet pressure prior to pump startup is not a significant parameter needed fe evaluating pump performance or its material condition?
Evalue#on: The licensee is requesting relief from measunng static inlet pressure prior to pump startup for nll pumps in the inservice testing program that may be in operation at the time the test j
is started Measurement of static inlet pressure prior to starting a pump and during a test is a requirement of ASME Section XI, f lWP4300 (Table IWP41001) However, inlet pressure is not i
intended to be used as a test pararneter for evaluating pump performance, and there are no i
acceptance criteria associated with it. Measurement of inlet pressure is included only to assist the licensee in the test set up process and alert them to the need for adequate suction pressure while Operating the pump.
In rulemaking to 10 CFR 50.55a effective September 8,1992 (see Federal Reaister. Vol. 57, No.
j-152, page 34666), the 1989 Edition of ASME Section XI was incorporated in paragraph (b) of 6 50.55a. The 1989 Edstion provides that the rules for inservice testing of pumps are as specsfied in 1
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ASMFJANSI OMa-1988 Part 6. The staff imposed no limitations to OMa-1988 Part 6. Section l
50.55a 1(f)(4)(iv) provides that inservice tests of pumps may meet the requirements set forth in J
sutaequent editions and addenda that are incorporated by reference in paragraph (b) of 6 50.55a, subject to the limitations and modifications listed, and subject to Commission approval. Portions of editions or addenda may be used provided that all related requirements of the respective editions or addenda are met.
Measuring inlet pressure is not required by ASMFJANSI OMa-1988, Part 6, since it is now recognized that the licensee is responsible for addressing testing limitations and prerequisites, l
and ensuring that they are incorporated into the procedures. Accordingly, the relief requested by the 'icensee is covered by the rulemaking effective September 8,1992, and relief is not required.
Approval of the deletion of inlet pressure measurement is recommended pursuant to $50.55a 4
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1(f)(4)(iv). There are no related requirements for the deletion, j
i 2.2 Diesel Fuel Oil System l
l 2.2.1 Pump Relief Request No. PR-7, Diesel Fuel Oil Transfer Pumps 2A,2B l
Belief Request: The licensee requests relief from the ASME Code,Section XI, f lWP-4600 which i
states that flow rate shall be measured using a rate or quantity meter installed in the pump test i
circuit for the Diesel Fuel Oil Transfer Pumps 2A and 28.
l ProposedNtemate Testing: "During quarterly testing of the Diesel Generator Fuel Oil Transfer s
Pumps, pump differential pressure, flow rate, and vibration will be recorded per IWP 3200 and j
IWP 6000. Flow rate will be based on the storage tank level changes over a measured period of pump operation.- The aliowable ranges for the test parameters as specified in Table IWP-3200-2 l
(sic) will be used for all measurements except for flow. In accordance with IWP-3200 and ASME i
Interpretation XI 179-19. the new pump flow limits and their calculations will be specified in the l
record of tests (IWP-6000).
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A series of at least four flow tests will be performed for each pump to establish a new pump baseline. The calculated average flow rate, F(avg), of these tests will be used for the pump's reference value. The mean arror for the individual flow rates and average flow rate will be calculated and combined by the sum of the squares to form a combined error (Sigma). The combined error will then be doubled (two standard deviations) to achieve a 95.4% accuracy that all acceptable flow rate tests will fall within this range. The new pump limits will be as follows:
Required Action
> [1.02 x F(avg)] + 2 Sigma Upper Alert
= [1.02 x F(avg)] + 2 Sigma Upper Acceptable
= [1.00 x F(avg)] + 2 Sigma l
Lower Acceptable
= [0.96 x F(avg)] - 2 Sigma Lower Alert
= [0.94 x F(avg)] - 2 Sigma Required Action
< [0.94 x F(avg)] - 2 Sigma The Lower Acceptable limit incorporates a 4% range for a small amount of pump degradation.
This is the same amount that is included in the limit listed in Table IWP-3200-2 (sic)."
licensee's Basis for Relief: The licensee states in Attachment 1 to the Revision 2 submittal letter that "The Unit 2 diesel fuel oil system does not have any installed flow instruments. Fuel oil must be pumped between storage tanks in order to measure pump flow rates. Relief is requested to perform this type of test.
In addition, the relief also describes the modified allowable ranges used to gage the pump operational readiness. The method of establishing the new allowable limits was included in this relief request for information only since both the ASME Code (IWP-3210) and the ASME Interpretation XI-179-19 permit the owner to modify the allowable ranges."
Additionally, in the relief request the licensee states that: "There are two flow paths available for performing inservice testing on these pumps: the normal day tank fill line and the transfer lines used to transfer fuel oil between diesel oil storage tanks. Neither of these flow paths have installed flow instrumentation.
The day tank would have to be drained to use it as the flow path for a pump flow test. To drain the day tank would require the pump to be disabled and additional diesel generator run time to use up the fuel oil or draining over 200 gallons of fuel oil into 55 gallon drums. Neither draining method is acceptable. Even if the tank could be drained, the length of the pump test would be limited by the small volume of the day tank.
The most practical method of determining pump flow rate is by calculating the transfer rate of fuel oil between storage tanks. The pump flow test is divided into two sections. The pump is recirculated for 15 minutes to its own storage tank (A) for the first section of the flow test. During these 15 minutes, the pump is warmed up and vibration measurements are taken. Prior to the end of the 15 minutes, the pump's discharge valva is throttled to a preset value. The pump is stopped and the valve kneup is changed so that flow is now directed to the other storage tank (B). While the pump's lineup is changed, the pump's storage tank (A) level is measured by hand using a tape measure. The pump is then started and allowed to transfer a minimum of 3 inches of fuel oil,5 to 6 inches is preferred. A final storage tank (A) level is measured at the end of the test. The pump's flow rate is calculated by converting the storage tank (A) level change into a volume change and then dividing it by the number of minutes the pump was run."
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' Evatuselon: The licensee is requesting relief from direct measurement of flow rate for the Diesel l
Fuel 05 Transfer Pumps 2A and 28 due to lack of instrumentation. Flow rate measurement is a j
requirement of Section XI,11WP-3100, f
' As discussed in Position 9 of Generic Letter 89 04, the NRC has estabhshed the position that flow rate determination is required for adequate testing. Lack of instrumentation is not suflicient justificahon for not complying with Code requirements. Per the NRC response to question 105 of the minutes of Public Meetings on Generic Letter 89 04 the installation of instrumentation to comply with Code requirements is not generally considered impractical.
1 However, calculation of pump flow rate based on measuring change in fuel oil storage tank level with respect to pump running time would provide an acceptable level of quality and safety for determining pump flow rate, provided the calculation !s properly proceduralized, and the accuracy.
j is within the accuracy required by the Code using direct measurement. Therefore, provided the licensee evaluates the accuracy and repeatability of manually measuring tank level with a tape measure, and it is within the requirements of the Code, and the calculation is properfy j
proceduralized, it is recommended that the licensee's alternative be authorized in accordance with j
$50.55a f(a)(3)(i).
1 The licensee has proposed new pump flow rate range limits in accordance with Section XI, f lWP-3210. Although relief is not required, when f lWP-3210 is used, the licensee must document the i
i basis for the expanded ranges and the basis that the pump pe formance does not demonstrate i
degrading conditions. The basis for acceptable pump performance, in either case, must be related to the pump and not the system, although system rec,9irements must be met. The j
licensee should include this documentation in the test records and it is subject to NRC inspection.
Additionally, the licensee should note that OMa-1988, Part 6 does not include this provision and the use of altomative ranges must be authorized by the NRC for the next interval.
l 2.2.2 Pump Relief Request PR-16, Diesel Fuel Oil Transfer Pumpe 2A and 28 I
Belief Request: The licensee requests relief from the ASME Code,Section XI Table IWP-3100-1, which states that each inservice test shall include the measurement and observation of suction l
and differential pressure for the Diesel Fuel Oil Transfer Pumps 2A and 20.
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a Proposed Altemate Testing: During the quarterly pump tests, the pumps' suction (inlet) pressure will be calculated based on the height of liquid in the associated tank. Subsequently, these calculated values will be used to determine pump differential pressure for evaluation of pump parameters.
Licensee's Basis for Relief: The licensee states that: "The system installation does not provide any installed suction gauges. A measure of pump suction pressure can, however, be determined i
by calculation using the height of liquid in the Diesel Oil Storage Tank. During the quarterly pump tests, the flow rate through the suction piping is very low, therefore, the amount of head loss is t
negligible.
Since the tank levels are not expected to vary significantly during the quarterly tests, tank levels and associated calculations will only be taken once during each quarterly test instead of prior to j
pump operation and during operation as required by Table IWP-3100-1."
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Evaluadon: A review of the licensee's drawing 2998-G486 Sheet 1, ' Flow Diagram -
Miscellaneous Systems," Revision 18, 5/30/89, indicates that there is no instrumentation to directly measure the inlet pressure of the diesel oil transfer pumps.
Lack of instrumentation is not sufficient justification for not complying with Code requirements, as discussed in response to question 105 of the Generic Letter 89-04 public meeting minutes.
However, calculation of inlet pressure based on the measured tank level would provide an acceptable alternative method of determining inlet pressure, provided the calculation is properly proceduralized, and the accuracy is within the accuracy required by the Code using direct measurement.
Based on the alternative providing an acceptable level of quality and safety, it is recommended that the alternative be authorized in accordance with $50.55a 1(a)(3)(i), provided that the accuracy of the reading scale of the level measurement is within Code requirements and calculation method is properly proceduralized.
2.3 Chamino System 2.3.1 Pump Relief Request PR-8, Boric Acid Makeup Pumps 2A,2B Rollet Request: The licensee requests relief from the ASME Code,Section XI, f lWP 3100, which requires that each inservice test shall include the measurement and observation of suction and differential pressure, for the Boric Acid Makeup Pumps 2A and 28.
Proposed Attemate Tes#ng: The Boric Acid Makeup Pump suction pressures will be calculated based on the height of liquid in the associated tank once during each inservice test.
Subsequently, these calculated values will be used to determine pump differential pressures for evaluation of pump parameters.
Ucensee's Basis for Relief: The licensee states that: "The system installation does not provide any mechanism for measuring pump suction pressure, and thus, the requirement for measuring suction pressure and pump differential pressures cannot be satisfied. A measure of pump suction pressure can, however, be determined by a calculation using the height of liquid in the boric acid makeup tanks. Since there is essentially fixed resistances between the tanks and the pumps this will provide a consistent value for suction pressures.
Since the tank levels are not expected to vary significantly during the tests, tank level and associated calculations will only be taken once during each test instead of prior to pump operation and during operation as required by Table IWP-3100-1.'
Evaluadon: A review of the licensee's drawing 2998-G-078, Sheet 121, ' Flow Diagram -Chemical &
Volume Control System (Sheet 2)," Revision 5, dated 10/20/89, indicates that there is no instrumentation to directly measure suction pressure of the Boric Acid Makeup pumps. Instead, the licensee proposes to use the height of liquid in the Boric Acid Makeup Tanks to determine pump suction pressure.
Lack of instrumentation is not sufficient justification for not complying with Code requirements, as discussed in response to question 105 of the Generic Letter 89-04 public meeting minutes.
However, calculation of inlet pressure based on the measured tank level would provide an acceptable alternative method of determining inlet pressure, provided the calculation is properly 8
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proceduralized, and the accuracy is within the accuracy required by the Code using direct measurement.
Based on the alternative providing an acceptable level of quality a.d safety, it is recommended that the alternative be authorized in accordance with 550.55a f(a)(3)(1), provided that the accuracy of the reading scale of the level measurement is within Code requirements and calculation method is properly proceduratived.
2.3.2 Pump Relief Request PR-12, Reactor Coolant Charging Pumps 2A,28, and 2C Rellet Request: The licensee requests relief from the ASME Code,Section XI, f lWP-4520(b),
which requires that the frequency response range of the readout system (for instruments used to measure vibration amplitude) shall be from one-half minimum speed to at least maximum pump shaft rotational speed, for the Reactor Coolant Charging Pumps 2A, 28 and 2C.
PrnposedAltemate Tes#ng: During testing of these pumps, vibration will be measured as required by f lWP4510, except that the lower frequency response for the instruments will be 10 Hz.
Ucensee's Bas /s for Relief: The licensee states that: "The reactor coolant charging pumps operate at approximately 210-215 RPM which equates to a rotational frequency of 3.5 Hz. In accordance with the ASME Code, the frequency response for the vibration instruments would have to be one half of this or 1.75 Hz. Following an extensive investigation of available and potentially suitable instrumentation, it has been determined that instrumer;ts satisfying this requirement for the charging pumps are commercially unavailable."
Evalua#on: The charging pumps operate at very low speeds.Section XI, f lWP4520(b), requires that the frequency response range of the readout system (for instruments used to measure vibration amplitude) shall be from one-half minimum speed to at least maximum pump shaft rotational speed for all pumps. Additionally, OMa-1988 Part 6 now requires that the frequency response range of the vibration measuring transducers and their readout system to be from one-third minimum pump speed to at least 1000 Hz, in order to more adequately envelop all potential noise contributors. The licensee will be required to update their Program this year to this standard. The lower limit of the range is to allow for detection of problems such as bearing oil whiri and looseness of bearings.
The licensee has proposed using vibration instrumentation that cannot measure subharmonic or the first or second harmonics. The licensee has stated that instrumentation that complies with the Code is commercially unavailable. However, equipment with a frequency response of less than 10 Hz is available. The licensee may also consider the use of spectral analysis to complement the Code vibration readings.
The licensee should evaluate whether the pumps are susceptible to degradation mechanisms that result in increased vibration levels at frequencies below 10 Hz. Also, the licensee has not discussed the repeatability and accuracy of the instruments to be used immediate imposition of the Code requirements is impractical due to limitations in the current instrumentation and it would be an undue burden to require the plan, to declare these pumps inoperable until the evaluation of subharmonic frequencies and/cr available instrumentation could be reviewed. Therefore, it is recommended that relief be granted for an interim period of one year, or until the next refueling 9
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outage, whichever is later. The interim relief remains in effect into the next ten-year interval due to j
begin August 9,1993.
2.4 intake Coolina Water System i
2.4.1 Pump Relief Request PR-11, intake Cooling Water Pumps 2A,2B,2C i
Relief Request: The licensee requests relief frorn the ASME Code,Section XI, i lWP 3100, which requires that each inservice test shallinclude the measurement and observation of suction and differential pressure, for the intake Cooling Water Pumps 2A, 28 and 2C.
ProposedAltomate Tes#ng: During testing of these pumps, one value of inlet pressure will be calculated based on water level at the inlet structure.
Licensee's Basis for Bellet: The licensee states that 'The pumps listed above are vertical line shaft pumps submerged in the intake structure with no practical means of measuring pump inlet pressure. The inlet pressure, however, can be determined by calculation using, as input, the i
measured height of water above the pump inlet as measured at the intake.
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1 During each inservice test, the water level in the intake pit remains relatively constant, thus only one measurement of level and the associated suction pressure calculation need be performed."
Evalue#on: A review of the licensee's drawing 2996-G 082, Ylow Diagram - Circulating and intake Cooling Water System,? Revision 23,10/20/89, indicates that there is no instrumentation to directly measure the inlet pressure of the intake cooling water pumps. Lack of instrumentation is not sufficient justification for not complying with Code requirements, as discussed in response to question 105 of the Generic Letter 8944 meeting minutes. However, calculation of inlet pressure based on the measured inlet structure level would provide an acceptable alternative method of determining inlet pressure, provided the calculation is properly proceduralized,'and the accuracy
. is within the accuracy required by the Code using direct measurement.
Based on the alternative providing an acceptable level of quality and safety, it is recommended that the attemative be authorized in accordance with $50.55a 1(a)(3)(i), provided that the accuracy of the reading scale of the level measurement and calculation method is acceptable.
2.4.2 Pump Relief Request PR-13, intake Cooling Water Pumps 2A,28,2C Relief Request: The licensee requests relief from the ASME Code,Section XI, i lWP-4520(b),
which requires that the frequency response range of the readout system (for instruments used to measure vibration amplitude) shall be from one-half minimum speed to at least maximum pump shaft rotational speed, for the intake Cooling Water Pumps 2A, 28, and 2C.
j Proposed Attemate Tes#ng: During testing of these pumps, vibration will be measured as required by Section XI,1 IWP-4510, except that the lower frequency response for the instruments j
will be 10 Hz.
- Licensee's Basis for Relief: The licensee states that "The St. Lucie Plant has recently completed a major upgrade to its ASME pump vibration program to better comply with the Code. As part of l
the upgrade, new vibration instruments were purchased. The instruments were chosen for their ease of use and reliability; however, the instrument's lower frequency response does not comply 10
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with the Code when used on the intake Cooling Water pumps. The intake cooling water pumps l
operate at a shaft speed of approximately 885 RPM. Based on this speed and the Code requirement, the instrumentation used to measure vibration (displacement) would require a q
response range down to 7.38 Hz. The new instruments are capable of a lower frequency response to 10 Hz,2.82 Hz higher than the Code. The impact of procuring instruments along l
with the accompanying re-training that would be required is clearfy unwarranted at this time
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simply to gain a slightly better frequency response."
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Evalua#on: The intake cooling water pumps operate at very low speeds. The shaft rotational speed is 885 RPM.Section XI, f lWP-4520(b), requires that the frequency response range of the readout system (for instruments used to measure vibration ampRtude) shaN be from one-half 4
minimum speed to at least maximum pump shaft rotational speed for aN pumps. Additionally, OMa-1988 Part 8 now requires that the frequency response range of the vibration measuring 1
transducers and their readout system to be from one-third minimum pump speed to at least 1000 Hz, in order to more adequately envelop all potential noise contributors. The licensee will be required to update their Program this year to this standard. The lower limit of the range is to 3
j aNow for detection of problems such as bearing oil whirt and looseness of bearings.
i The pump's shaft speed translates to a frequency of 14.75 Hz. Therefore, the code required frequency range is 7.38 Hz to 14.75 Hz. By measuring an actual frequency range of 10 Hz to 4
j 14.75 Hz, the licensee is measuring only 64.36% of the code required range. Therefore, the j
licensee's claim that procuring instruments capable of measuring down to 7.38 Hz would yield i
only a slightly better frequency response appears to be unjustified, 3
Although the licensee recently purchased vibration instrumentation, the licensee should evaluate j
the procurement of instrumentation that complies with the Code requirements for this interval and the next interval and provide a detailed description of the burden or impracticality of complying l
with the Code. Additionally, the licensee should evaluate whether the intake cooling water pumps are susceptible to degradation mechanisms that result in increased vibration levels at frequencies below 10 Hz. Immediate imposition of the Code requirements is impractical due to limitations in the current instrumentation ar.d it would be an undue burden to require the plant to declare these pumps inoperable until the evaluation of subharmonic frequencies and/or available instrumentation could be reviewed. It is therefore recommended that relief be granted for an j
interim period of one year or until the next refueling outage, whichever is later. The interim relief j
remain in effect into the next ten-year interval due to begin August 9,1993.
2.5 Containment Sorav and Safety inloction Systems 2.5.1 Pump Rollef Request PR-15, Containment Spray Pumps 2A and 2B; High Pressure Safety injection Pumps 2A and 2B; and Low Pressure Safety injection Pumps 2A and 3
i 2B Belief Request: The licensee requests relief from the ASME Code,Section XI,1 IWP-3100, which requires that each inservice test shall include the measurement and observation of suction and differential pressure, for the 2A and 28 Containment Spray, High Pressure Safety injection, and i
Low Pressure Safety injection Pumps.
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'l Proposed Altemate Testing: During the quarterly pump tests, the pumps' suction (inlet) pressures will be calculated based on the height of liquid in the associated tank. Subsequently, these i
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calculated values will be used to determine pump differential pressures for evaluation of pump parameters.
During the cold shutdown or refueling substantial flow testing of these pumps, temporary suction gages will be installed to measure pump suction pressure.
L/censee's Bas /s for Relief: The licensee states that "The system installation does not provide any installed suction gages. A measure of pump suction pressure can, however, be determined by calculation using the height of liquid in the Refueling Water Tank. During the quarterly pump tests, the flow rate through the suction piping is very low, therefore, the amount of head loss is negligible. This is not the case during the substantial flow tests. The flow rates used during these tests would cause a noticeable head loss in the suction piping.
Since the tank levels are not expected to vary significantly during the quarterly tests, tank levels and associated calculations will only be taken once during each quarterly test instead of prior to pump operation and during operation as required by Table IWP-3100-1."
Evalua#on: The licensee is requesting relief from measuring inlet pressure and differential pressure for the 2A and 28 Containment Spray, High Pressure Safety injection, and Low Pressure Safety injection pumps. Measurement of inlet pressure and differential pressure is a requirement of the ASME Code,Section XI, f lWP-3100 (Table IWP-3100-1).
Reference to the licensee's drawing 2998-G 088, ' Flow Diagram - Containment Spray and Refueling Water Systems," Revision 13, 10/20/89, indicated that there appear to be two pressure transmitters PX 07-1 A.2A and PX 07-18, 28 at the suction of each Containment Spray pump, respectively. The licensee should use these pressure transmitters or discuss in the relief request why they cannot be utilized.
Ucensee drawing 2998-G 078, Sheet 130, ' Flow Diagram - Safety injection System (Sheet 1),'
Revision 4,10/20/89, indicates that there is no instrumentation to directly measure the inlet pressure of the High Pressure and Low Pressure Safety injection pumps, except for differential pressure switches across the pump suction strainers. Lack of instrumentation is not sufficient justification for not complying with Code requirements, as discussed in response to question 105 of the Generic Letter 89-04 meeting minutes. However, calculation of inlet pressure based on the measured tank level would provide an acceptable alternative method of determining inlet pressure, provided the calculation is properly proceduralized, and the accuracy is within the accuracy required by the Code using direct measurement.
Based on the alternative providing an acceptable level of quality and safety,it is recommended that the alternative be authorized in accordance with $50.55a 1(a)(3)(i), provided that the accuracy of the reading scale of the level measurement is within Code requirements and calculation method is properly proceduralized. The licensee should evaluate the feasibility of measuring pump inlet pressure using the pressure transmitters on the Containment Spray pump inlet lines, I
and use these instruments if practical.
2.5.2 Pump Relief Request PR-14, Containment Spray System Hydrazine Pumps 2A and 28 Relief Request: The licensee requests relief from the ASME Code,Section XI,1 IWP-4520(b),
j which requires that the frequency response range of the readout system (for instruments used to 12
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I measure vibration amplitude) shall be from one-half minimum speed to at least maximum pump
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shaft rotational speed, for the Containment Spray System Hydrazine Pumps 2A and 28.
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ProposedNiernate Tes#ng: During testing of these pumps, vibration will be measured as.
required by f lWP 4510, except that the lower frequency response for the instruments will be 10 f
3 licensee's Basis for Relief: The licensee states that: "The hydrazine pumps operate as low as 105 rpms. This equates to a rotational frequency of 1.75 Hz. In accordance with the ASME Code, the i
j frequency response for the vibration instruments would have to be one half of this or 0.875 Hz.
Following an extensive investigation of available and potentially sustable instrumentation, it has i
j been determined that instruments satisfying this requirement for the hydrazine pumps are commercially unavailable.'
j-Evalus#ont' The containment spray hydrazine pumps operate at very low speeds.Section XI,1 IWP-4520(b), requires that the frequency response range of the readout system (for instruments i
used to measure vibration amplitude) shall be from one-half minimum speed to at least maximum i
pump shaft rotational speed for all pumps. Additionally, OMa-1988 Part 6 now requires that the l
frequency response range of the vibration measuring transducers and their readout system to be i
from one-third minimum pump speed to at least 1000 Hz, in order to more adequately envelop all potential noise contributors. The licensee will be required to update their Program this year to j
this standard. The lower limit of the range is to allow for detection of problems such as bearing
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oil whirt and looseness of bearings.
The licensee has proposed using vibration instrumentation that cannot measure subharmonic or
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the first to fifth harmonic. The licensee has stated that instrumentation that complies with the l
Code is commercially unavailable. However, equipment with a frequency response of less than 10 Hz is available. The licensee may also consider the use of spectral analysis to complement the Code vibration readings. The licensee should evaluate whether the pumps are susceptible to
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degradation mechanisms that result in increased vibration levels at frequencies below 10 Hz.
Immediate imposition of the Code requirements is impractical due to limitations in the current instrumentation and it would be an undue burden to require the plant to declare these pumps inoperable until the evaluation of subharmonic frequencies and/or available instrumentation could be reviewed it is therefore recommended that relief be granted for an interim period of one year l
or until the next refueling outage, whichever is later. The interim relief remains in effect into the next ten-year interval due to begin August 9,1993.
2.5.3 Pump Relief Request PR-17, Containment Spray System Hydrazine Pumps 2A and 2B Relief Request: The licensee requests relief from the ASME Code. Section XI:
1.
1 IWP-3200 and IWP-3300, which require evaluation of pump differential pressure and flow rate quarterly, and appropriate corrective actions, and 2.
11WP-4150, which states that symmetrical damping devices or averaging techniques may be used to reduce instrument fluctuations to within 2% of the observed reading, for the Containment Spray System Hydrazine Pumps 2A and 28.
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Proposed Altemate Tes#ng: During the quarterly pump tests, each pump's rpm will be measured to verify the required flow rate of 0.71 to 0.82 gpm. Pump flow will be recorded but not alert trended and vibration will be measured during the quarterly tests. During each refueling outage, j.
at least one flow test will be performed for each pump to verify proper performance.- Pump j.
vibration will be measured during this flow test.
l" LJcensee's Basis for Railef: The licensee states that: "The Hydrazine Pumps are positive
'i displacement pumps with a variable speed drive. They operate at a very low rpm and flow rate j
(0.71 to 0.82 gpm). The flow instrument orifice is located in the pump's suction line. Its output j
l signal pulsates sharply with each stroke and cannot readily be averaged. The flow recorder for i
the hydrazine pumps, FR 07 2, displays a wide trace for flow rate. The only way to know the true flow rate of the pumps is to collect the pumps output in a container and measure it.
i i
During the 1992 Unit 2 refueling outage, several flow tests per hydrazine pump were performed.
i The discharge of one pump was directed to a container of a known volume. The amount of time i
to fill the container was measured and then used to calculate an average flow rate for the pump.
I Each of the flow tests for each pump were performed at a different pump rpm. A correlation between pump rpm and average flow rate was developed and compared to the expected value.
The measured and the expected correlations between rpm and flow rate were in close agreement.
3 The expected correlation was based upon piston diameter, piston stroke, and pump rpm. Based
-l a
upon these results, hydrazine pump flow rate car; 53 accurately set by selecting the proper pump rpm.
l-Frequent performance of the above mentioned flow testing can not be performed. Hydrazine is a highly flammable liquid with cumulative toxic effect when absorbed through the skin, inhaled, or l
ingested. It has also been identified as a known carcinogen."
i i
1 l
Evalua#on: The licensee has proposed recording flowrate quarterly, but flowrate will not be " alert trended."Section XI, flWP-3200 requires flowrate to be measured and corrective actions taken, that is by either increasing the test frequency or declaring the pump inoperative, if the measured 7
t value is in the alert or required action range, respectively. Reforring to the licensee's basis, it is -
assumed that the licensee will not take any corrective actions based on the measured flowrate i
exceeding the alert or required action values. The licensee should evaluate the establishment of required action ranges for quarterly testing.
The licensee has referenced Section XI 1 IWP-4150 in the relief request, however the licensee has j
not discussed the possible use of a symmetrical damping device to provide for flow rate i
averaging. Additionally, the licensee has not discussed the impact or burden of installing flow instrumentation that could be used effectively for the quarterly test.
In Generic Letter 8944, Position 9, the staff determined that in cases where flow can only be 1
established through a non-instrumented minimum flow path during quarterly pump testing and a path exists at cold shutdowns or refueling outages to perform a test of the pump under full or substantial flow condillons, the increased interval is an acceptable alternative to the Code requirements provided that pump differential pressure, flow rate, and bearing vibration measurements are taken during this testing and that quarterly testing also includes measuring at
' least pump differential pressure and vibration.
Reference.to the licensee's Appendix A, Pump Program Table, Revision 2,08/01/92, indicates that the licensee will not measure the pump inlet pressure or differential pressure. The ASME/ ANSI 14
Code OMa-1988, Part 6, Table 3b, requires that pump discharge pressure be measured for positive displacement pumps. The licensee has not provided a basis for not measuring pump differential or discharge pressure.
Provided the licensee determines that there is no practical means of insta!!ing flow instrumentation that is adequate for inservice testing purposes, deferring flowrate measurement to refueling outages may be considered acceptable. The licensee should, however, evaluate the procurement of damping devices or new flow instrumentation, and measure and evaluate pump differential or discharge pressure as well as vibration quarterly.
Immediate imposition of the Code requirements is impractical due to lack of adequate installed flow instrumentation, and it would be an undue burden to require the plant to declare these pumps inoperable until the availability of new instrumentation could be reviewed. Therefore it is recommended that relief be granted for an interim period of one year, or until the next refueling outage, which ever is later. The interim relief remains in effect into the next ten-year interval due to begin August 9,1993. In the interim, the licensee should establish acceptance criteria rpm / flow rate correlation and measure discharge pressure if possible.
3.0 VALVE IST PROGRAM RELIEF REQUESTS in accordance with $50.55a, FP&L has submitted thirty-four relief requests for specific and generic valves at the St. Lucie Plant, Unit 2 that are subject to inservice testing under the requirements of ASME Section XI. The fourteen relief requests referenced in Attachment 1 of FP&L's September 15,1992 letter and in their January 13,1993 letter have been reviewed to verify their technical basis and determine their acceptability. Each relief request that is not authorized by Generic Letter 89 04 is summarized below, along with the technical evaluation by BNL 3.1 Generic Valve Relief Requests 3.1.1 Valve Relief Request VR-1, All Valves Tested During Cold Shutdown Relief Request The licensee requests relief from exercising all cold shutdown frequency valves every cold shutdown, as required by Section XI,13412(a) and 3522.
Proposed Alternate Testing: "For those valves designated to be exercised or tested during cold shutdown, exercising shall commence as soon as practical after the plant reaches a stable cold shutdown condition, as defined by the applicable Technical Specification, but no later than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> after reaching cold shutdown. If the outage is long enough to test all the cold shutdown valves, then the 48-hour requirement need not apply. If the 48-hour requirement is waived, then all cold shutdown valves must be tested during the outage.
Valve testing need not be performed more often than once every three (3) months except as provided for in lWV-3417(a). Completion of all valve testing during a cold shutdown outage is not required if the length of the shutdown period is insufficient to complete all testing. Testing not completed prior to startup may be rescheduled for the next shutdown in a sequence such that the test schedule does not omit nor favor certain valves or groups of valves."
Licensee's Basis for Relief: The licensee states: "In many instances testing of all valves designated for testing during cold shutdown cannot be completed due to the brevity of an outage or the lack of plant conditions needed for testing specific valves. It has been the policy of the 15
NRC that if testing commences in a reasonable time and reasonable efforts are made to test all i
valves, then outage extension or significant changes in plant conditions are not required when the only reason is to provide the opportunity for completion of valve testing.
ASME/ ANSI OMa-1987 (sic), Operation and Maintenance of Nuclear Power Plants Part 10 (Paragraphs 4.2.1.2 and 4.3.2.2) recognizes this issue and allows deferred testing as set forth below" (i.e., in the description of the Proposed Alternate Testing).
Evalua#on: In rulemaking to to CFR 50.55a effective September 8,1992 (see Federal Reaister.
Vol. 57, No.152, page 34666), the 1989 Edition of ASME Section XI was incorporated in paragraph (b) of f 50.55a. The 1989 Edition provides that the rules for inservice testing of valves j
are as specified in ASME/ ANSI OMa-1988 Part 10. The staffimposed no limitations to OMa-1988 Part to related to cold shutdown testing. Section 50.55a 1(f)(4)(iv) provides that inservice tests of j
valves may meet the requirements set forth in subsequent editions and addenda that are incorporated by reference in paragraph (b) of f 50.55a, subject to the limitations and modifications listed, and subject to Commission approval. Portions of editions or addenda may be used provided that all related requirements of the respective editions or addenda are rnet.
The ASME recognized the burden of requiring licensees to complete all cold shutdown frequency inservice testing every cold shutdown. ASME/ ANSI OMa-1988, Part 10 now allows plant startup without the completion of all cold shutdown frequency testing, provided the licensee commences testing within 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />. The licensee's request to utilize OMa-1988, Part 10,14.2.1.2 and 4.3.2.2, is covered by the rulemaking effective September 8,1992, relief is not required. Approval for implementation is recommended pursuant to 50.55a 1 (f)(4)(iv). The documentation requirements of OM-10,16.2 must continue to be met. Implementation is subject to NRC inspection.
3.2 Safety inlection System 3.2.1 Valve Relief Request VR 2, Safety injection System Pressure isolation Valve (PlV)
Check Valves Relief Request: The licensee requests relief from the requirements of ASME Section XI, f lWV-3427(b), which requires leakage trending, and corrective actions based on the trend results, for the following pressure isolation check valves (PlVs) in the Safety injection System:
V-3217 V-3227 V-3237 V-3247 V-3258 V-3259 V-3260 V-3261 V-3215 V-3225 V-3235 V-3245 V-3524 V-3525 V-3526 V-3527 Proposed Alternate Testing: The leakage rate acceptance criteria for these valves will be established per the St. Lucie Unit 2 Technical Specifications, Table 3.4-1. Leakage rates greater than 1.0 GPM are unacceptable.
Each Reactor Coolant System Pressure Isolation Valve check valve shall be demonstrated operable by verifying leakage to be within its limits:
16
1.
At least once per 18 months.
2.
Prior to enterireg MODE 2 whenever the plant has been in COLD SHUTDOWN for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or more and if leakage testing has not been performed in the previous 9 months.
3.
Prior to returning the valve to service following maintenance, repair or replacement work on the valve.
4.
Following flow through valve (s) while in MODES 1,2,3 or 4:
A.
Within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> by verifying valve closure, and B.
Within 31 days by verifying leakage rate.
l 5.
Following flow through valve (s) while in MODES 5 or 6:
A.
Within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of entering MODE 4 by verifying valve closure, and B.
Within 31 days of entering MODE 4 by verifying leakage rate.
t/censee's Basis for Rollet: The licensee states that: " Leak testing of these valves is primarily for the purpose of confirming their capability of preventing overpressurization and catastrophic failure i
.of the safety infection piping and components. In this regard, special leakage acceptance criteria is established and included in the St. Lucie 2 Technical Specifications (Table 3.41) that addresses the question of valve integrity in a more appropriate manner for these valves. Satisfying both the Technical Specification and the Code acceptance criteria is not warranted and implementation would be difficult and confusing. Specifically applying the trending requirements of IWV-3427 (b)
]
would result in frequent and excessive maintenance of these valves. The continuation of a strict i
~
leak rate acceptance criteria and more frequent testing than specified by the Code give a high degree of assurance that these valves will satisfactorily perform their safety function."
Evalua#on: The ASME Code,Section XI,1 IWV-3427(b), states that for Category C valves NPS 6 and larger, if a leakage rate exceeds the rate determined by the previous test by an amount that reduces the margin between measured leakage rate and the maximum permissible rate by 50% or greater, the test frequency shall be doubled; the tests sha% be scheduled to coincide with a cold shutdown until corrective action is taken, at which time the original test frequency shall be resumed. If tests show a leakage rate increasing with time, and a projection based on three or more tests indicates that the leakage rate of the next scheduled test will exceed the maximum permissible leakage rate by greater than 10%, the valve shall be replaced or repaired.
Several safety systems connected to the reactor coolant pressure boundary have design pressures below the RCS operating pressure. Redundant isolation valves within the Class 1 boundary forming the interface between these high and low pressure systems protect the low pressure systems from pressures that exceed their design limit. In this role, the valves perform a pressure isolation function. The NRC considers the redundant isolation provided by these valves to be important because it has been demonstrated that the failure of the boundary created by j
these valves is a dominant accident scenario if the valves are not tested. The NRC considers it necessary to assure that the condition of each of these valves is adequate to maintain this redundant isolation and system integrity.
17 l
Consequently, these pressure isolation valves are identified in the Plant Technical Specifications s
along with specific requirements to monitor their leakage rates periodically. Each of the check l
l valves has a maximum alicwable leak rate of 1.0 GPM.
a in rulemaking to 10CFR50.55a effective September 8,1992 (see Federal Reoister. Vol. 57, No.
4' 152, page 34666), the 1989 Edition of ASME Section XI was incorporated in paragraph (b) of 5 50.55a. The 1980 Edition provides that the rules for inservice testing of valves are as specified in ASMFJANSI OMa-1988 Part 10. The staff imposed no limitations to OMa-1988 Part 10 concerning pressure isolation valves. Section 50.55a 1(f)(4)(iv) provides that inservice tests of valves may meet the requirements set forth in subsequent editions and addenda that are incorporated by i
j reference in paragraph (b) of 9 50.55a, subject to the limitations and modifications listed, and subject to Commission approval. Portions of editions or addenda may be used provided that all related requirements of the respective editions or addenda are met.
Increasing the frequency of testing for valves NPS 6 and larger whose leakage rate exceeds the j
criteria described in Section XI, f lWV-3427(b) is not required by ASME/ ANSI OMa-1988, Part 10, 14.2.2. Instead,14.2.2.3(f) requires that valves or valve combinations with leakage rates exceeding the values specified by the Owner in 14.2.2.3(e) shall be declared inoperable and l
either repaired or replaced. A retest demonstrating acceptable operation shall be performed following any required corrective action before the valve is returned to service.
I The licensee's proposed alternate testing, which includes limiting the acceptable leakage flow rate l
to 1.0 GPM, meets the requirements of Part 10,14.2.2.3(e) and (f). OM 10,14.2.2.3(e) requires l
leakage rates to be specified by the Owner. If not specified 0.5 D or 5.0 GPM may be used.
1 Therefore, approval to not trend leakage as required by f lWV-3427(b) is recommended pursuant to 50.55a 1 (f)(4)(iv). There are no related requirements for the deletion.
i 3.2.2 Valve Relief Request VR-13, Safety injection Tank to Reactor Coolant System Check Valves V-3215, V-3225, V-3235, and V-3245 i
i Relief Request: The licensee requests relief from full stroke exercising open and closed the 12 in.
i check valves, V-3215, V-3225, V-3235, and V-3245, in each of the discharge lines from the Safety injection Tanks (SIT) to the Reactor Coolant System quarterly or at cold shutdowns in accordance with Section XI,1IWV-3521 and IWV-3522.
Proposed Altemate Testing: At least once during each ISI (10 year) inspection interval each of these valves will be disassembled, inspected, and manually stroked to verify operability. Should a valve under inspection be found to be inoperable, then the remaining three valves will be inspected during the same outage. Assurance of proper reassembly will be provided by performing a leak test or partial flow test prior to returning a valve to service following disassembly.
These valves will be verified closed in conjunction with PlV leak testing. The leakage rate j
acceptance criteria for these valves will be established per the St. Lucie Unit 2 Technica!
Specifications, Table 3.4-1. Leakage rates greater than 1.0 GPM are unacceptable.
Each Reactor Coolant System Pressure Isolation Valve check valve shall be demonstrated I
operable by verifying leakage to be within its limits:
l 18
~
4 I
1 1
l 1.
At least once per 18 months.
2.
Prior to entering MODE 2 whenever the plant has been in COLD SHUTDOWN for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or more gg if leakage testing has not been performed in the previous 9 months.
l l
3.
Prior to returning the valve to service following maintenance, repair or replacement work i
on the valve.
t 4
4.
_ Following flow through valve (s) while in MODES 1, 2,3, or 4:
1 A.
Within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> by verifying valve closure, and j
i 8.
Within 31 days by verifying leakage rate.
j i
5.
FoNowing flow through valve (s) while in MODES 5 or 6:
A.
Within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of entering MODE 4 by verifying valve closure, and B.
Within 31 days of entering MODE 4 by verifying leakage rate.
j j
4 1
Licensee's Basis for Relief: The licensee states: " Full stroke exercising of these valves would j
require injecting from a tank under nominal pressure into a de-pressurized reactor coolant system.
_l At power operation this is not possible because the Si Tank prossure is insufficient to overcome j
reactor coolant system pressure.
Under a large break LOCA accident conditions, the maximum (peak) flow rate through these
~
valves would be approximately 20,000 GPM. During cold shutdown or refueling the required test i
conditions for developing this full accident flow cannot be established, j-The SIT discharge isolation valves are motor operated valves with a nominal stroke time of 52 seconds. Therefore, the isolation valve cannot be used to simulate the LOCA flow conditions by opening it with a full or partially pressurized SIT. The discharge flow rate would only increase gradually due to the long stroke time of the discharge isolation valve.~ The flow rate would not be anywhere near the expected peak blowdown rate of 20,000 GPM expected during a large break
+
LOCA..
l 1
~ FP&L has reviewed the operating and maintenance history of these valves and similar valves used g
throughout the industry under comparable conditions. Based on these reviews, there is no evidence of valve degradation with respect to their ability to open and satisfactorily pass the l
required flow. It is apparent from the failure data that the primary mode of failure is related to i
- valve leakage - both past the seat and extemal through the body-bonnet and hinge pin gasket joints. It should also be noted that these valves are not subjected to any significant flow during plant operation as well as maintenance periods; thus it is unlikely that these valves would j
l experience any service-related damage or wear.
e Although check valve disassembly is a valuable maintenance tool that can provide a great deal of
-)
information about a valve's internal condition, due to the difficulties associated with these maintenance activities, it should only be performed under the maintenance program at a l
frequency commensurate with the valve type and service, in this light, FP&L considers the l
frequency of inspection for these valves of once each 10-year inspection interval to be adequate j
to ensure the continued operability of these valves.
?
19 l
4 I
i i
These are simple check valves with no extemal means of position indication, thus the only practical means of verifying closure is by performing a leak test or back flow test. The back flow tests are performed as part of the pressure isolation testing per VR-2."
i l
j Evalua#on: Section XI requires check valves to be exercised to the position (s) in which the valves perform their safety function (s). These 12 in. check valves open to provide flow path from the safety injection tanks to the RCS and close to isolate the tanks from the high pressure of the reactor coolant system and the safety injection headers.
4 As discussed in Generic Letter 89 04,' Position 1, the NRC considers passing the maximum
{
required accident condition flowrate through the valve as an acceptable means of verifying that a check valve can full-stroke open. The NRC recognized that it may be impractical to perform full flow testing of certain check valves and noted that it may be possible to qualify other techniques
{
to confirm that the valve is exercised to the position required to perform its safety function. When full-stroke exercising is impractical, disassembly and inspection is an acceptable altemative j
technique, as described in Position 2. However, the NRC considers disassembly and inspection a j
maintenance procedure and not a test equivalent to the exercising produced by fluid flow. This procedure has some risk, which makes its routine use as a substitute for testing undesirable when 4
j some other method of testing is practical. Check valve disassembly is a valuable maintenance tool that can provide significant information about a valve's internal condition and, as such, should a
I l
be performed under the maintenance program at a frequency commensurate with the valve type and service.
l J
l Although, the licensee states that testing with the maximum required accident flowrate is not practical, an analysis or test should be performed to show that the nominal 52 seconds stroke time for the SIT discharge isolation motor-operated valves to open is too long to permit sufficient
]
flow to cause the check valves to reach their full-open position. If a full-open position can be i
[
reached, the licensee should perform the test with flow to confirm disk position.
)
1 The use of attemate techniques, such as non-intrusive techniques, to verify that the valves are j
fully open is acceptable, as discussed in Generic Letter 89 04, Position 1, when full-flow testing is impractical. Furthermore, the use of non-intrusive techniques has been demonstrated to be less costly and less risky than disassembly and inspection (Reference The Nuclear Professional, page 31, Vol. 7. No. 4, Fall 1992). To substantiate the acceptability of any attemative technique for meeting the ASME Code requirements, licensees must, as a minimum, address and document f
certain items in the IST program, as described in Position 1. The licensee should note that other C-E plants, such as Palisades, have included in their IST Program full-stroke exercising the SI Tank check valves open at refueling outages.
l l
However, if the licensee determines that full-stroke exercising with flow is impractical, the licensee may, as discussed by the NRC in Generic Letter Position 2, perform valve disassembly and inspection as a positive means of determining that a valve's disk will full-stroke exercise open or i
of verifying closure capability.
I' The licensee is currently proposing to utilize Position 2. Assurance of proper reassembly will be i
provided by performing a leak test or partial-flow test prior to retuming a valve to service following disassembly. However, the licensee intends to inspect each check valve only once in the 10 year inservice Inspection program interval. As deflned in Position 2 of the Generic Letter,in order to support extension of the vdve disassembly / inspection intervals to longer than once every 6 years, i.e., in cases of ' extreme hardship," licensees should develop the following information:
1 i
i 20 i
i
.~
i I
a.
Disassemble and inspect each valve in the valve grouping and document in detail the condition of each valve and the valvvs capability to be full-stroked.
I b.
A review of industry experience,' for example, as documented in NPRDS, regarding the same type of valve used in similar service.
[
c.
A review of the instaNation of each valve addressing the "EPRI Applications Guidelines for i
Check Valves in Nuclear Power Plants" for prob!ematic locations.
[
The licensee has documented parts a and b above, but has provided no discussion concerning the EPRI Guidelines in part c above or the extreme hardship. The licensee should discuss why non-intrusives cannot be util' zed when evaluating hardship. Additionally, the licensee states that j
valve.wNI be leak tested or partial-flow tested following riisassembly. Position 2 requires that, if 4
possible, partial.
<e stroking quarterly or during cold shutdowns, or after reassembly, must be f
p., form.d.
t l
In summary, relief is granted per Generic Letter 89-04, Posi. ion 1, to full-stroke exercise the valves l
open with less than the accident flow rate, provided all criteria in Position 1 are met. If the i
licensee determines that full-stroke exercising is impractical, relief is granted per Position 2 to l
disassemble / inspect these check valves, provided the licensee meets all the criteria in Position 2 E
including reviewing the instaNation of the valves, demonstrating extreme hardship, and partial-i stroke exercising the valves following reassembly and at cold shutdown if practical.
l
{
With respect to exercising the valve closed, verification that a valve is in the closed position can j
be done by visual observation, by an electrical signal initiated by a position-indicating device, by j
observation of appropriate pressure indication in the system, by leak testing, or by other positive i
l means.
s i
These are simple check valves which are not provided with instrumentation, and the only means i
of testing these valves closed is by leak testing. Backflow leakage tes'.ing is performed under the j
licensee's program for Pressure Isolation Valves, as described in TER Section 3.2.1.
si i
it is impractical to test these valves quarterly or during every cold shutdown because the valves i
and test connections are located inside containment. Access to testing presents a personnel i
safety hazard due to high radiation levels and proximity to high energy systems. Leak testing these valves during every cold shutdown would be burdensome to the licensee due to the i
extensive test setup, which would require substantial man-hours and the potential for extending the shutdown.
I in rulemaking to 10 CFR 50.55a effective September 8,1992, the 1989 Edition of ASME Section XI 1
was incorporated in paragraph (b) of f 50.55a. The 1989 Edition provides that the rules for inservice testing of valves are as specified in OMa-1988 Part 10. The NRC staff imposed no l_
limitations to OMa-1988 Part 10 associated with testing valves during refueling. Section 50.55a 1 j
(f)(4)(iv) provides that inservice testing of valves may meet the requirements set forth in subsequent editions and addenda that are incorporated by reference in paragraph (b) of $50.55a, subject to the limitations and modifications listed, and subject to NRC approval. Portions of editions and addenda may be used provided that all related requirements of the respective
[
editions and addenda are met.
i i
T 21 9
1
-n,
7 J
1 I
l OMa-1988 Part 10,14.3.2.2 allows full-stroke exercising that is not practicable during operation or 1
cold shutdown to be deferred to refueling outages. Accordingly, the alternatwo testing proposed l
l by the licensee in the closed direction is covered by the rulemaking, effective September 8,1992, j
as described above. Relief is not required provided the licensee implements all related requirements, including Part 10,14.3.2.2(h) and 16.2. Approval is recommended pursuant to 550.55a 1(f)(4)(iv). Implementation of these related requirements is subject to NRC inspection.
i 3.2.3 Valve Relief Request VR-14, Safety injection Headers to Reactor Coolant System Check Valves V-3217, V-3227, V-3237, and V-3247 1
i Relief Request: The licensee requests relief from full-stroke exercising the 12 in. Safety injection check valves V-3217, V-3227, V 3237, and V-3247, open and closed quarterly and at cold 1
shutdowns as required by the ASME Code,Section XI, f lWV-3522. These valves open to provide flow paths from the safety injection headers to the RCS and close to isolate the headers from the i-high pressure of the reactor coolant system.
Proposed Allemate Testing: During cold shutdown and refueling periods, each of these valves will
]
be partial-stroke exercised with approximately 3,000 GPM (20 percent of maximum accident flow) using the LPSI pump per Relief Request VR-1.
At least once during each ISI (10 year) inspectio. btervs!, each of these valves will be I
disassembled, inspected, and manually stroked to verify operability. Should a valve under I
inspection be found to be inoperable, then the remaining three valves will be inspected during the 3
same outage. Assurance of proper reassembly will be provided by performing a leak test or 1
partial-flow test prior to returning a valve to service following disassembly.
I These valves will be verified closed in conjunction with PlV leak testing. The leakage rate acceptance criteria for these valves will be established per the St. Lucie Unit 2 Technical l
Specifications, Table 3.41. Leakage rates greater than 1.0 GPM are unacceptable.
Each Reactor Coolant System Pressure isolation Valve check valve shall be demonstrated l
operable by verifying leakage to be within its limits:
1.
At least once per 18 months.
2.
Prior to entering MODE 2 whenever the plant has been in COLD SHUTDOWN for 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or more and if leakage testing has not been performed in the previous 9 months.
3.
Prior to returning the valve to service following maintenance, repair or replacement work j
on the valve.
l l
1 4.
Following flow through valve (s) while in MODES 1,2,3, or 4:
1 I
A.
Within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> by verifying valve closure, and B.
Within 31 days by verifying 1eakage rate.
22 i
)
5.
Following flow through valve (s) while in MODES 5 or 6:
A.
Within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of entering MODE 4 by. verifying valve closure, and B.
Within 31 days of entering MODE 4 by verifying leakage rate.
j
]
Licensee's Basis for Relief: The licensee states: Full stroke exercising of these valves would require injecting from a tank under nominal pressure into a de-pressurized reactor coolant system.
l At power operation this is not possible because the St Tank pressure is insuffeient to overcome l
reactor coolant system pressure.
1 Under a large break LOCA accident conditions, the maximum (peak) flow rate through these j
- valves would be approximately 20,000 GPM. During cold st.utdown or refueling the required test j
conditions for developing this full accident flow cannot be established. The SIT discharge isolation valves are motor operated valves with a nominal stroke time of 52 seconds.' Therefore, the isolation valve cannot be used to simulate the LOCA flow conditions by opening it with a fully j
or partially pressurized SIT. The discharge flow rate would only increase gradually due to the long stroke time of the discharge isolation valve. The flow rate would not be arrywhere near the l
expected peak blowdown rate of 20,000 GPM expected during a large break LOCA.
l l
FP&L has reviewed the operating and maintenance history of these valves and similar valves used 1
throughout the industry under comparable conditions. Thess four valves have been in operation 1
i in Unit 2 since the plant startup in 1983. A total of 2 plant work orders have been initiated for l
work on these valves. Of the two work orders, one was to repair seat leakage identitled by a seat leakage test and the other was for disassernbly and inspection per Generic Letter 8944. A search of the Nuclear Plant Reliability Data System for problems with valves similar to these j
revealed 12 reports - 7 due to seat leakage and the remaining 5 were related to gasket leaks.
Based on these reviews there is no evidence of valve degradation with respect to their ability to j
open and satisfactorily pass the required flow, it is apparent from the failure d*ta that the primary mode of failure is related to valve leakage both past the seat and extemal through the body-j' bonnet and hinge pin gasket joints.
In order to disassemble and inspect these valves, the reactor coolant system must be placed in i
mid-loop or ' reduced inventory' condition for several days, in response to issues raised in NRC
{.
Generic Letter 88-17. FP&L is concerned about continued operations with the plant in a condition of reduced inventory. During these periods, the risk of over-heating the core is increased due to the higher probability of an incident where shutdown cooling is lost. This risk is compounded by the reduced volume of water available to act as a heat sink should cooling be Icst. Since 1982 I
there have been at least six (6) reported events in the industry where cooling flow was lost while a plant was in a ' reduced inventory' condition.
4 Although check valve disassembly is a valuable maintenance tool that can provide a great deal of information about a valve's internal condition,' due to the difficulties associated with these maintenance activities, it should only be performed under the maintenance program at a j
frequency commensurate with the valve type and service. Given the lack of evidence that these valves are experiencing significant failures with respect to their capability of passing the design flow rates and the apparent sensitivity of the valves to leak testing, a frequency of inspection for these valves of once each 10-year inspection interval is adequate to ensure the continued operability of these valves.
4 3
23
These are simple check valves with no external means of position indication, thus the only practical means of verifying closure is by performing a leak test or back flow test. The back flow testing is performed as stated in VR 2. In addition to periodic leak testing, the upstream pressure of each valve is monitored by a pressure indicator and alarm. Should any of these valves begin to leak by, the upstream pressure alarm would alert plant personnel of the leakage."
Evaluadon: Section XI requires check valves to be exercised to the position (s) in which the valves perform their safety function (s). These 12 in. check valves open to provide flow paths from the safety injection headers to the RCS and close to isolate the headers from the high pressure of the reactor coolant system.
As discussed in Generic Letter 89-04, Position 1, the NRC considers passing the maximum required accident condition flowrate through the valve as an acceptable means of verifying that a check valve can full-stroke open. The NRC recognized that it may be impractical to perform full flow testing of certain check v.tives and noted that it may be possible to qualify other techniques to confirm that the valve is exercised to the position required to perform its safety tunction. When full-stroke exercising is impractical, disassembly and inspection is an acceptable alternative technique, as described in Position 2. However, the NRC considers disassembly and inspection a maintenance procedure and not a test equivalent to the exercising produced by fluid flow. This procedure has some risk, which makes its routine use as a substitute for testing undesirable when some other method of testing is practical. Check valve disassembly is a valuable maintenance tool that can provide significant information about a valve's internal condition and, as such, should be performed under the maintenance program at a frequency commensurate with the valve type and service.
The licensee states that during cold shutdown and refueling periods, each of these valves will be partial-stroke exercised with approximately 3,000 GPM (20 percent of maximum accident flow) using the LPSI pump. The licensee should evaluate if the valves will achieve a full-open position with this reduced flow rate, if a full-open position can be reached, the licensee should perform the testing with flow. The use of alternate techniques, such as non-intrusive techniques, to verify that valves will fully open is acceptable, as discussed in Generic Letter 89-04, Position 1.
If the valves cannot be full-stroke exercised, the NRC defined an acceptable alternative to the full-stroke exercising requirement in Generic Letter 89-04, Position 2, wherein it is stated that valve disassembly and inspection can be used as a positive means of determining that a valve's disk will full-stroke exercise open or of verifying closure capability, as permitted by i lWV-3522.
The licensee is currently proposing to utilize Position 2. Assurance of proper reassembly will be provided by performing a leak test or partial-flow test prior to returning a valve to service following disassembly. However, the licensee intends to inspect each check valve only once in the 10 year Inservice inspection program interval. As defined in Position 2 of the generic letter, in order to support extension of the valve disassembly / inspection intervals to longer than once every 6 years, i.e., in cases of " extreme hardship," licensees should develop the following information:
a.
Disassemble and inspect each valve in the valve grouping and document in detail the condition of each valve and the valve's capability to be full-stroked, b.
A review of industry experience, for example, as documented in NPRDS, regarding the same type of valve used in similar service.
24
. _. _ _. _ _ _ _ _ _ _ _ _ _ _ _. _ _ _ _ _ _... _ _ _.. ~. _
i J
f A review of the installation of each valve addressing the "EPRI Applications Guidelines for c.
l Check Valves in Nuclear Power Plants' for problematic locations.
The licensee has documented parts a and b above, but has provided no discussion concerning the EPRI Guidelines in part c above. The licensee should include a discussion of why non-intrusives cannot be utilized when proposing disassembly and inspectum Addisonally, the licensee states that valve will be leak tested or partial-flow tested following disassembly. Position l
2 requires that, if possible, partal valve stroking quarterly or during cold shutdowns, or after j.
reassembly, must be performed.
in summary, relief is granted per Generic Letter 8944, Position 1, to full-stroke exercise the valves f
open with less than the accident flow rate, provided all criteria in Position 1 are met. If the licensee determines that full-stroke exercising is impractical, relief is granted per Posthon 2 to l
disassemble / inspect these check valves, provided the licensee meets aN the criteria in Position 2, includmg reviewing the instagation of the valves, demonstrating extreme hardship, and partial-j' stroke exercising following reassembly and at cold shutdown if practical.
I With respect to exercising the valves closed, verification that a valve is in the closed position can a
l be done by visual observation, by an electrical signal initiated by a position-indicating device, by j
observation of appropriate pressure indication in the system, by leak testing, or by other positive means. The licensee does have instrumentation to continuously monitor upstream pressure.
Based on the Technical Specifications, it appears that following the partial-stroke exercise at cold shutdowns, verification that the valves have closed will be performed and relief would not be required. The licensee should exercise these valves closed at cold shutdowns or revise the request accordingly.
3.2.4 Valve Relief Request VR-29, Safety injection System Motor-Operated Valvea V-3480, V-3481, V-3661, V-3652 Aelief Request: The licensee requests relief from the requirements of ASME Section XI, f lWV-1 3427(b), which requ' ires leakage trending, and corrective actions based on the trend results, for j
the 10 in. Safety injection System motor-operated valves V-3ACO, V-3481, V-3651, and V-3652.
Proposed Altemate Testing: The leakage rate acceptance criteria for these valves will be established per the St. Lucie Unit 2 Technical Specifications Table 3.4-1, as applicable for motor-operated valves:
i 1.
Leakage rates greater than 1.0 GPM but less than or equal to 5.0 GPM are acceptable if l
the latest measured rate has not exceeded the rate determined by the Revious test by an i
amount that reduces the margin between measured leakage rate and the maximum l
permissible rate of 5.0 gpm by 50% or greater.
2.
Leakage rates greater than 1.0 GPM, but less than or equal to 5.0 GPM, are unacceptable if the latest measured rate exceeded the rate determined by the previous test by an i
amount that reduces the margin between measured leakage rate and the maximum j
. permissible rate of 5.0 GPM by 50% or greater.
3.
Leakage rates greater than 5.0 GPM are unacceptable.
i 25
l p
1 l
Each Reactor Coolant System Pressure isolation Valve motor-operated valve shall be
[
demonstrated operable by vertfying leakage to be within its limits:
[
1.
At least once per 18 months, and I
i 2.
Prior to returning the valve to service following maintenance, repair, or replacement work j
on the valve.
j licensee's Basis for Relief: The licensee states that: " Leak testing of these valves is pnmarily for i
the purpose of confirming their capability of preventing overpressurization and catastrophic failure j
of the safety irjection piping and components. In this regard, special leakage acceptance criteria -
i is established and included in the St. Lucie 2 Technical Spedfications (Table 3.4-1) that addresses j
the question of valve integrity in a more appropriate manner for these valves. Satisfying both the
)
Tedmical Specification and the Code acceptance criteria is not warranted and implementation j.
would be difficult and confusing."
j l
l Ewedua#on: The licensee requests selief from the ASME Code,Section XI, f lWV-3427(b), which requires that for Category A valves NPS 6 or larger, if a leakage rate exceeds the rate determined by the previous test by an amount that reduces the margin between measured leakage rate and the maxrnum permissible leakage rate by 50% or ;; mater, the test frequency shall be doubled; the tests shall be scheduled to coincide with a cold shutdown until corrective action is taken, at which time the original test frequency shall be resumed. If tests show a leakage rate increasing with time, and a projection based on three or more tests indicates that the leakage rate of the next scheduled test will exceed the maximum permissible leakage rate by greater than 10%, the valve shall be replaced or repaired.
Several safety systems connected to the reactor coolant pressure boundary have' design I
pressures below the RCS operating pressure. Redundant isolation valves within the Class 1 boundary forming the interface between these high and low pressure systems protect the low pressure systems from pressures that exceed their' design limit. In this role, the valves perform a pressure isolation function. The NRC considers the redundant isolation provided by these valves to be important because it has been demonstrated that the failure of the boundary created by these valves is a dominant accident scenario if the valves are not tested. The NRC considers it i
necessary to assure that the condition of each of these valves is adequate to maintain this redundant isolation and system integrity. Consequently, these pressure isolation valves are identified in the Plant Technical Specifications along with specific requirements to monitor their leakage rates periodically.
The subject motor-operated valves open for residual heat removal recirculation during shutdown.
Each of these valves is designated as a pressure isolation valve (PlV) and provides isolation of safeguard systems from the RCS.
In rulemaking to 10CFR50.55a effective September 8,1992 (see Federal Reaister. Vol. 57, No.
]
152, page 34666), the 1989 Edition of ASME Section XI was incorporated in paragraph (b) of 9 i
50.55a. The 1989 Edition provides that the rules for inservice testing of valves are as specified in j
' ASME/ ANSI OMa 1988 Part 10. The staff imposed no limitations to OMa-1988 Part 10, concerning pressure isolation valves. Section 50.55a 1(f)(4)(iv) provides that inservice tests of valves may meet the requirements set forth in subsequent editions and addenda that are incorporated by _
reference in paragraph (b) of f 50.55a, subject to the limitations and modifications listed, and -
.I
^
26 I
subject to Commission approval. Portions of editions or addenda may be used provided that all related requirements of the respective editions or addenda are met.
Increasing the frequency of testing for valves NPS 6 and larger whose leakage rate exceeds the criteria described in Section XI, f lWV-3427(b) is not required by ASME/ ANSI OMa-1988, Part 10, 14.2.2.3(f). Instead,14.2.2.3(f) requires that valves or valve combinations with leakage rates exceeding the values specified by the Owner in 14.2.2.3(e) shall be declared inoperable and either repaired or replaced. A retest demonstrating acceptable operation shall be performed following any required corrective action before the valve is returned to service.
The licensee's proposed alternate to use the Technical Specification requirements, which includes limiting the acceptable leakage flow rate to 5.0 GPM, meets the requirements of Part 10,1 4.2.2.3(e) and (f). Therefore, because the alternative meets later Code requirements, relief is not required. Approval is recommended pursuant to 950.55a 1(f)(4)(iv).
3.3 Containment Isolation Valves 3.3.1 Valve Relief Request VR-4, Primary Containment isolation Valves Relief Request: The licensee requests relief from ASME,Section XI,1 IWV-3426 and IWV-3427, which requires individual leak rates for Category A valves to be evaluated and corrected.
The subject valves are:
PENETRATION NO.
VALVES 10 FCV 25-4 and Blank Flange 11 FCV-25-2 and FCV-25-3 23 HCV-141 and HCV 14-7 24 HCV 14-2 and HCV 14-6 41 SE 03-2A and SE-03-2B 1
54 V-OO101 and Blank Flange j
56 FCV-25-36 and FCV-25 26 57 FCV 25-20 and FCV 25-21 Proposed Altemate Testing: The above stated valves and blank flanges will be leak rate tested in pairs. Leakage measurement from tests of multiple valves or blank flanges will be evaluated in accordance with Section XI, i lWV-3426 and i lWV-3427.
Licensee's Basis for Relief: The licensee states that: "For several containment systems, individual leakage rate tests are impractical due to the configuration of the system's piping and components, in these cases it is customary to perform leakage tests with the test volume between valves in series or behind valves in parallel paths.
in these cases where individual valve testing is impractical, the valves will be leak tested simultaneously in multiple valve arrangements. A maximum permissible leakage rate will be applied to each combination of valves or valve and blank flange. In each of the valve pairs, the two valves are equal in size and type, and the leakage limit is in proportion to their size. The blank flanges used in testing penetrations to and 54 have diameters similar in size to their 27
=a-4=ted valves FCV-25-4 and V 00101, The leakage limit assigned to each pair is such that excessive leakage through any valve, or flange, would be detectable and the appropriate f
. corrective action taken."
Evatus#on: The subject valves are Category A or A/C valves which are closed to provide containment isolation.Section XI,1 lWV-3426 requires that Category A or A/C valves be seat leak tested ana that a maximum individual permissible leakage rate be specified for each valve. The licensee is proposing to leak rate test the subject containment isolation valves in pairs.
In rulemaking to 10 CFR 50.55a effective September 8,1992 (see Federal Recaster. Vol. 57, No.
152, page 34666), the 1989 Edition of ASME Section XI was incorporated in paragraph (b) of f 50.55a. The 1989 Edition provides that the rules for inservice testing of valves are as specified in l
OMa 1988 Part 10. The NRC staff imposed limitations to OMa-1988 Part 10 associated with containment isolation valves (CIVs) to require the leakage rate analysis and corrective action requirements of OM-10,14.2.2.3(e) and (f) to be applied to CIVs. Sec8on 50.55a 1 (f)(4)(iv) provides that inservice testing of valves may meet the requirements set forth in subsequent editions and addenda that are incorporated by reference in paragraph (b) of 550.55a, subject to l
the limitations and modifications listed, and subject to NRC approval. Portions of editions and addenda may be used provided that all related requirements of the respec8ve editions and addenda are met.
ASME/ ANSI OMa-1988, Part 10,14.2.2.3(e) and (f) allows valves to be tested in combinations or groups. Where two or more valves on a containment penetration are tested as a group, limiting j
leakage-rate values must be assigned to the group for the purpose of monitoring valve condition and taking corrective action. The limits should be established such that leakage of any valve in j
the group would be identified, based on the diameter of the smallest valve in the group or based on a conservative limit established to another criterion not related to the diameter of the valve.
The licensee has adequately described the leakage rate limits by indicating that the valves will be tested in pairs and the leakage rate limit is proportional to size and is adequate to detect degradation. Additionally, the licensee will analyze and perform corrective actions in accordance with Section XI,1 IWV-3426 and 1 IWV-3427. The Section XI,1 IWV 3426,3427(a), and 3200 requirements are equivalent to OMa-1988, Part 10,14.2.2.3(e) and (f). Accordingly, the altamative requested by the licensee is covered by the rulemaking, effective September 8,1992, as described above, and relief, therefore, is not required. Approval is recommended pursuant to
$50.55a 1(f)(4)(iv).
3.3.2 Valve Relief Request VR-18, Primary Make-Up Water System Containment isolation Check Valve V-15328 Reliet Request: The licensee requests relief from exercising the 2 in. Primary Make-Up Water System containment isolation check valve V 15328 quarterly or at cold shutdowns, as required by i
the ASME Code,Section XI, i lWV 3521 and 3522.
Proposed Altemate Testing: At least once every two (2) years, this valve will be verified to close in conjunction with the Appendix J leak testing program.
' Licensee's Basis for Relief: The licensee states that: "This is a simple check valve with no extemal
' means of position indication, thus the only practical means of verifying closure is by performing a
- leak test or back flow test. This test would require a considerable effort since this system is the j
i 28
i a
1 only source of fire fighting water for the containment building. In order to back flow or leak test the check valve, this system would have to be isolated. In order to isolate the system, an
)
l altemate source of fire fighting water would first have to be supplied to the containment building.
This would require rigging several fire hoses through the maintenance hatch to the various fire
(.
fighting stations in the containment building. This would constitute an undue burden to perform this test during normal operation and during cold shutdowns."
Evalua#on: This ASME Section XI, Category A/C valve, is the containment isolation valve for the primary make-up water supply line to the containment.Section XI requires check valvet, to be exercised to the position (s) in which the valves perform their safety function. The only safety function of this valve is in the closed position. Confirmation that the valve is in the closed direction can be done by visual observation, by an electrical signal initiated by a position i
i indicating device, by observation of appropriate pressure indications, by leak testing, or by other i
positive means.
i The valve is not provided with position indication or pressure instn.
ntation. The only available method for testing this valve is by leak testing. It is impractical to tu this valve quarterly or i
during cold shutdowns because the valve and test connections are located inside containment and the licensee has demonstrated that an undue burden would exist to leak test the valve in that j
an alternate source of fire fighting water to the containment building would have to be established.
4 In rulemaking to 10 CFR 50.55a effective September 8,1992, the 1989 Edition of ASME Section XI
- was incorporated in paragraph (b) of 6 50.55a. The 1989 Edition provides that the rules for inservice testing of valves are as specified in OMa-1988 Part 10. The NRC staffimposed no
- limitations to OMa-1988 Part 10 associated with testing valves during cold shutdown or refueling.
{
Section 50.55a 1 (f)(4)(iv) provides that inservice testing of valves may meet the requirements set forth in subsequent editions and addenda that are incorporated by reference in paragraph (b) of i
550.55a, subject to the limitations and modifications listed, and subject to NRC approval. Portions of editions and addenda may be used provided that all related require'nents of the respectsve
- 1 editions and addenda are met.
OMa-1988 Part 10,14.2.2.2 requires that Category A valves, which are containment isolation valves, shall be seat leak tested in accordance with Federal Regulation 10 CFR So, Appendix J.
3 l
Appendix J requires that such testing be performed during each refueling, but in no case at i
intervals greater than 2 years, i
Part 10,14.3.2.1, however, requires that check valves shall be exercised nominally every 3 months, except as provided by 14.3.2.2. Specifically,14.3.2.2(e) states that if exercising (to the position required to fulfill its function, i.e., closed) is not practicable during plant operation or cold shutdowns, it may be limited to full-stroke during refueling outages.
i Accordingly, the relief requested by the licensee is covered by the rulemaking, effective September 8,1992, as described above, and relief is not required, provided that the proposed alternative testing is performed at least during every refueling, even if the refueling interval is less j
than 2 years, and that all related requirements (i.e.,14.3,2.2(h) and 6.2) are implemented.
Approval is recommended pursuant to 55.55a 1 (f)(4)(iv). Implementation of related requirements j_
is subject to NRC inspection.
t j
29 d
.m
_. _, _ _.. _ _ _. _ _. ~ _.. -. _ _ _ - _ _. _ _
i-3.3.3 Valve Relief Request VR-19, instrument Air Header Containment Isolation Check j~
Valve V-18195 Relief Roguest: The licensee requests relief from exercising the 2 in. Instrument Air header containment isolation check valve V-18195 quarterly and at cold shutdowns as required by the ASME Code,Section XI, f lWV 3521 and 3522.
e I
PrqposedAttemate Tes#ng: At least once every two (2) years, this valve will be verified to close in j
conjunction with the Appendix J leak testing program.
2 L/censee's Basis for Relief: The licensee states that: "This is a simple check valve with no extemal i
mean of position indication, thus the only practical means of verifying closure is by performing a leak test or back flow test. This would require a considerable effort, including entry into the containment building and securing all instrument air inside the containment. There are over 50 i
valves, instruments, and controllers supplied by this one line. During a normal refueling outage, an altamate instrument air compressor must be connected to the isolated section of instrument air line in order to supply air to these cornponents during the Appendix J local leakage testing. The hose from the air compressor to the instrument air line must be routed through the containment maintenance hatch. Opening this hatch for the test alone would extend the amount of time that the unit would spend in cold shutdown, thus extending the outage. Testing of this valve would be an unreasonable burden on the plant staff to perfca". whi!e in cold shutdown.'
Evalua#on: This is a 2" ASME Section XI Category A/C valve, which is the containment isolation valve for the instrument Air header supply line to the containment at penetration 9.Section XI requires check valves to be exercised to the position (s) in which the valves perform their safety function. The only safety function of this valve is in the closed position. Confirmation that the valve is in the closed direction can be done by visual observation, by an electrical signal initiated by a position indicating device, by observation of appropriate pressure indications, by leak testing,,
or by other positive means. The valve in question is not provided with position indication or pressure instrumentation.
l The only available method for testing this valve is by leak testing. It is impractical to test this valve quarterly or during cold shutdowns because the valve and/or test connections are located inside containment and the licensee has demonstrated that an undue burden would exist to leak test the valve in that it would be necessary to secure all instrument air inside containment and route a -
hose from an alternate instrument air' compressor through the maintenance hatch, thus extending the time in cold shutdown.
In rulemaking to 10 CFR 50.55a effective September 8,1992, the 1989 Edition of ASME Section XI was incorporated in paragraph (b) of f 50.55a.' The 1989 Edition provides that the rules for inservice testing of valves are as specified in OMa-1988 Part 10. The NRC staff imposed no limitations to OMa-1988 Part 10 associated with testing valves during cold shutdown or refueling.
Section 50.55a 1 (f)(4)(iv) provides that inservice testing of valves may meet the requirements set forth in subsequent editions and addenda that are incorporated by reference in paragraph (b) of 650.55a, subject to the limitations and modifications listed, and subject to NRC approval. Portions of editions and addenda may be used provided that all related requirements of the respective editions and addenda are met.-
OMa-1988 Part 10,14.2.2.2 requires that Category A valves, which are containment isolation valves, shall be seat leak tested in accordance with Federal Regulation 10 CFR 50, Appendix J.
30 e+
w.
---e, e
-r y
m-aim-.
.c
Appendix J requires that such testing be performed during refueling, but in no case at intervals greater than 2 years.
Part 10,14.3.2.1, however, requires that check valves shall be exercised nominally every 3 months, except as provided by 14.3.2.2. Specifically,14.3.2.2(e) states that if exercising (to the position required to fulfill its function, i.e., closed) is not practicable during plant operation or cold shutdowns, it may be limited to full-stroke during refueling outages.
Accordingly, the relief requested by the licensee is covered by the rulemaking, effective September 8,1992, as described above, and relief is not required, provided that the proposed a!ternative testing is performed at least during every refueling, even if the refueling interval is less than 2 years, and that all related requirements (i.e.,14.3.2.2(h) and 6.2) are implemented.
Approval is recommended pursuant to 950.55a 1(f)(4)(iv). Implementation of related requirements is subject to NRC inspection.
3.4 Containment Spray System 3.4.1 Valve Relief Request VR 24, Containment Spray System Hydrazine Pump Discharge Check Valves V-07256 and V-07258 Relief Request: The licensee requests relief from exercising the 1/2 in. Containment Spray System hydrazine pump discharge check valves quarterly or during cold shutdowns as required by the ASME Code,Section XI, i lWV-3521 and 3522. These valves open to allow flow from the hydrazine pumps to the respective containment spray pump suction header.
Proposed Alternate Tesdng: During each reactor refueling outage these valves will be flow tested.
Licensee's Bas /s for Relief: The licensee states that: " Testing these valves using the only flow path available (via the hydrazine pumps) would contaminate the containment spray system and refueling water tank with hydrazine. Each of the hydrazine pumps discharge through its check valve into the suction piping of its containment spray pump. The hydrazine would then be pumped to the RWT during the quarterly containment spray pump Code test using the mini-flow recirculation line. Continued testing would build up the concentration of hydrazine in the RWT and deplete the level in its storage tank."
Evaluadon: A review of drawings 2998-G-088, ' Flow Diagram Containment Spray and Refueling Water Systems,' Rev.19, dated 10/20/89 and 2998-G-078 Sh.130, ' Flow Diagram Safety injection System (Sheet 1)," Rev. 4, dated 10/20/89, confirms that each of these hydrazine pump discharge check valves is located downstream of the hydrazine pump motor-operated discharge isolation va!ve in a 1/2 in. line leading to the suction header of the corresponding Containment Spray pump. To quarterly flow test the hydrazine pumps, flow is recirculated back to the Hydrazine Storage Tank (HST) through connections upstream of the pump motor-operated discharge isolation, so no flow is passed through the pump discharge check valves to perform the quarterly pump tests.
Since each of the hydrazine pumps discharge through its check valve into the suction piping of its corresponding Containment Spray pump, the licensee states that to flow test the check valves, each Containment Spray pump must be operated and flow recirculated back to the Refueling Water Tank (RWT). The licensee states that continued testing would build up concentration of hydrazine in the RWT and deplete the level in the HST. The licensee should explain specifically 31
______m_._
J why hydrazine buildup in the RWT is detrimental and could not be reduced or removed. Also, the licensee has not explained why the level of hydrazine in the HST could not be restored.
j Additionally, upon review of the flow diagrams it appears that the valves could be tested at cold shutdowns without operating the containment spray pumps by isolating the containment spray l, _
pumps manual suction and discharge valves and collecting the hydrazine through the 1 in. test connection at the pumps suction. The licensee should consider this test configuration.
e l.
In rulemaking to 10 CFR 50.55a effective September 8,1992, the 1989 Edition of ASME Section XI j
was incorporated in paragraph (b) of 5.50.55a. The 1989 Edition provides that the rules for -
i j
!nservice testing of valves are as specified in OMa-1988 Part 10. The NRC staff imposed no limitations to OMa-1988 Part 10 associated with testing valves during cold shutdown or refueling.
Section 50.55a 1 (f)(4)(iv) provides that inservice testing of valves may meet the requirements set forth in subsequent editions and addenda that are incorporated by reference in paragraph (b) of i -
550.55a, subject to the limitations and modifications listed, and subject to NRC approval. Portions i
of editions and addenda may be used provided that all related requirements of the respective j
editions and addenda are met.
OMa-1988 Part 10,14.3.2.2 allows full-stroke exercising that is not practicable during plant
- operation or cold shutdowns to be deferred to refueling outages. Accordingly, the relief p
requested by the licensee is covered by the rulemaking, effective September 8,1992, as described above, and relief is not required, provided that the licensee clarifies the impract6cality of l
testing caused by buildup of hydrazine in the RWT and the depletion of the level in the HST, i'
determines that testing using the 1 in. pump suction drain connection is impractical and implements the related requirements of 16.2 and 4.3.2.2(g). Implementation of the related requirements is subject to NRC inspection.
3.5 Emeraency Diesel Generator Air Startina System I
3.5.1 Valve Relief Request VR 26, Emergency Diesel Generator Starting Air Valves FCV-591 A1 to FCV-59-4A1, FCV 59-1B1 to FCV-59-481, SE-59-3A to SE-59-6A, and SE-59-3B to SE 59-68.
}L Relief Request The licensee has requested relief from the stroke time exercising and frequency
)
{
requirements for the 1.5 in. control air to the diesel generator air-operated gate valves, FCV-59-IAI through FCV-59-4Al, FCV-59-lBI through FCV 59 4B1, and solenoid operated gate valves, i
SE-59-3A through SE-594A, and SE-59-3B through SE-5948, as required by the ASME Code, l
Section XI,1 IWV 3413(b). These valves open to supply starting air to the emergency diesel l
generators.
4 Proposed Altemate Testing: These valves will be exercised in conjunction with testing of the emergency diesel generators. Both the 2A and 2B diesel generators will be started each month.
Every 6 months, these 16 air start system valves will be tested for proper operation by observing the operation of each associated pair of air start motors. The stroke times of the individual valves will not be measured.
Licensee's Basis for Relief: The licensee states that: 'These valves are integral with the diesel air start system for each emergency diesel generator. These valves have no valve position indication mechanism and, as such, there is no practical method for measuring the stroke times of each individual valve. If one of these valves were to fail to stroke, one of the four pairs of air start 32 1
motors would fall to opercte. Since one pair of air start motors is able to start the diesel generator, the diesel generator air start system has a redundancy of four for these valves.
The surveillance for starting and running each diesel generator is performed each month. The air start motor surveillance is performed every 6 months. This surveillance isolates three of the air start motor pairs and the fourth pair has air throttled to it. A diese! generator start signal is manually inserted and the un-isolated motor pair is observed for proper operation. The process is repeated for the other three pairs. The 6 month surveillance frequency was chosen to maximize the system reliability while minimizing the amount of time the diesel generators are maintained out of service for surveillance."
Evaluadon: The ASME Code requires that the stroke tirne of all power operated valves be measured and that corrective action (i.e., increasing test frequency or declaring valve inoperable) be taken when the tirne exceeds *.he alert limits or limiting value specified by the Owner, respectively. The intent of Section XI is to require the measurement of valve stroke times as a means of monitoring valve degradation and to take timely corrective action.
These valves open to supply starting air to the emergency diesel generators. Each diesel generator set consists of two diesel engines mounted in tandem with a 3800 !<W generator.
Therefore, Emergency Diesel Generator 2A consists of one 16-cylinder diesel engine 2A1 and one 12-cylinder diesel engine 2A2. Similarly, Emergency Diesel Generator 2B consists of one 16-cylinder diesel engine 281 and one 12-cylinder diesel engine 282. Since the diesels are in tandem, once one individual diesel engine is started using a pair of air start rnotr>rs, the counterpart diesel engine is also started. The air start system is designed with redundant air start valves and headers on each engine, i.e., there is a redundancy of four for these va,lves. For examnte,16-cylinder d'esel engine 2A1 is supplied with starting air by one pair of air start motors 2A1 North associated with air-operated control valve 21-FCV-59-1 A1 and solenoid valve 21-SE 3A, and also by a second pair of air stad motors 2A1 South associated with air-operated control valve 21-FCV-59-4A1 and solenoid valve 21-SE-59-4A. The operation of one pair of air-starting motors will verify the operation of both the associated control valve and the solenoid valve.
The licensee is committed by the Technical Specifications to start the 2A and 2B Emergency Diesel Generators monthly and has proposed to test the 16 air start system valves for proper operation by observing the operation of each associated pair of air start motors every six months.
These valves have no mechanism for position indication so that it is impractical to measure valve stroke time using conventional techniques. For both the monthly and the 6 month tests, the stroke times of the individual valves will not be measured. The monthly diesel start tests are performed using all four banks of control air, so that excessive valve degradation could occur undetected in as many as three out of four banks.
Although the valves' stroke Jmes cannot be measured by conventional means, the stroke times can be measured indirectly by monitoring diesel start times or by non-intrusive methods, e.g.,
using acoustic or diagnostic systems. Using diesel start times, any degradation in the valves' stroke times would result in longer diesel start times. A maximum limiting start time should be specified that is less than or equal to the Technical Specification requirement. If this limiting start time is exceeded due to degradation or failure of the air start system valves or motor operators, they should be declared inoperable and repaired or replaced.
33
With respect to test frequency, the licensee has not adequately demonstrated any undue burden caused by quarterly testing. Further information regarding the reason why a 6 month test interval provides an acceptable level of quality and safety should also be provided.
immediate imposition of the Code requirements is impractical due to the current valve design. It would be an undue burden to require the plant to declare the valves inoperable until the licensee could evaluate and establish a method for determining degradation. Based on the performance of oiesel generator testing, it is recommended that relief be granted for an interim period of one year, or until the next refueling outage, whichever is later. The interim relief remains in effect into the next ten-year interval due to begin August 9,1993. In the interim, the licensee should evaluate the establishment of a maximum limiting start time or some other method to detect i
degradation and the performance of testing in accordance with the Code required frequency.
Additionally, the licensee should review the Code classification of these valves. As discussed in Question 54 of the minutes of the public meeting on Generic Letter 8944, diesel generator air start systems are not typically Class 1,2, or 3, and are, therefore, not required by 10CFR50.55a to be tested in accordance with Section XI. If the licensee determines that these valves are not required to be Class 1,2, or 3; relief from Section XI is not required.
The licensee should, however, ensure that these valves are tested commensurate with their safety significance, as required by 10CFR50, Appendix A j
3.6 Auxiliary Feedwater System 3.6.1 Valve Relief Request VR-33, Auxiliary Feedwater System Flow Control Solenold-Operated Valves SE-09 2, SE-09-3, SE-09-4, and SE-09-5 Relief Request: The licensee requests relief from trending valve stroke times quarterly and increasing the test frequency to monthly based on an increase in stroke time relative to the previous test for 4 in. Auxiliary Feedwater System solenoid-operated valves SE-09-2, SE-09-3, SE-09-4, and SE-09-5, as required by the ASME Code,Section XI,1 IWV-3417(a). These solenoid valves cycle open and closed during an AFAS actuation to control auxiliary feedwater flow to the steam generators.
j Proposed Altemate Testing: During quarterly testing, these valves will be exercised and fail-safe tested during which their stroke time will be recorded. However, the valves' stroke times will not be compared to previous tests. If the maximum allowed stroke time is exceeded, then the valves will be placed out of service.
The licensee states that ' Testing performed during cold shutdown will record and trend the valves' stroke times. Should a valve's stroke time exceed its alert limit, it will be placed in alert and will be addressed prior to startup. Cold shutdown testing will be conducted per VR 1."
L/censee's Basis for Relief: The licensee states that: "These four valves are piloted, normally closed, solenoid globe valves made by the Target Rock Corporation. When their solenoid coil is energized the magnetic force lifts the Pilot Disk, opening the Pilot Orifice in the Main Disk. Any pressure in the chamber above the Main Disk can now vent off through the Pilot Orifice to the downstream side of the valve. With the pressure vented above the Main Disk, the upstream pressure acting on the lower side of the Main Disk can now lift if off the Main Seat, rapidly opening the valve, in the absence of a pressure differential, no pressure force exists tending to 34
seat the disc, therefore the magnetic force of the Solenoid Coil is sufficient, acting through the Stem, Pilot Disc, and Pin, to directly lift the Main Disc off the seat, opening the valve. The stroke times measured without differential pressure are not only slower, they also vary significantly from test to test causing the valves to be placed into alert unnecessarily. Therefore, St. Lucie requests i
relief from IWV-3417(a), the alert trending of valve stroke times, for the quarterly stroke test.
l The valves require the AFW pumps to be running and discharging into the steam generators to develop the differential pressure for the stroking of these valves. Pumping from the auxiliary feedwater into the steam generators during normal operation is impractical and undesirable.
I Injecting the relatively cold auxiliary feedwater into the main feedwater line while the plant is l
operating at power would cause a large temperature differential (approximately 375'F).
Significant thermal shock and fatigue cycling of the feedwater piping and steam generator nozzles could result.'
Evalua#on: Section XI, i lWV-3417(a) states that 'If, for power operated valves, an increase in stroke time of 25% or more from the previous test for valves Mth full-stroke times greater than 10 sec. or 50% or more for valves with full-stroke time less than or equal to 10 sec is observed, test i
frequency shall be increased to once each month until corrective action is taken..."
The valves in question, ASME Code Category B valves, which cycle open and close during an AFAS actuation to control auxiliary feedwater flow to the steam generators, are piloted, normally closed, solenoid globe valves made by the Target Rock Corporation. Because of the valve design, the stroke times must be measured without differential pressure. The licensee claims that the measured stroke times are not only slower, but they also vary significantly from test to test causing the valves to be placed into alert unnecessarily.
In rulemaking to 10 CFR 50.55a effective September 8,1992, the 1989 Edition of ASME Section XI was incorporated in paragraph (b) of 9 50.55a. The 1989 Edition provides that the rules for inservice testing of valves are as specified in OMa 1988 Part 10. The NRC staff imposed no limitations to OMa-1988 Part 10 associated with stroke time measurements. Section 50.55a 1 (f)(4)(iv) provides that inservice testing of valves may meet the requirements set forth in subsequent editions and addenda that are incorporated by reference in paragraph (b) of $50.55a.
subject to the limitations and modifications listed, and subject to NRC approval. Portions of editions and addenda may be used provided that all related requirements of the respective editions and addenda are met.
OMa-1988, Part 10,13.3 requires that reference values shall be determined from the results of preservice testing or from the results of inservice testing. There tests shall be performed under conditions as near as practicable to those expected during subsequent inservice testing. Part 10, 13.5 permits the establishment of an additional set of reference values if it is necessary or desirable for some other reason, other than as stated in 13.4, i.e., when a valve or its control j
system has been replaced, repaired, or has undergono maintenance that could affect the valve's l
performance. Therefore, if test conditio" 'or the quarterly tests are different from those at cold I
shutdown, an additional set of referent
/ can be established.
OMa-1988 Part 10 does not require alert trending. Part 10, 1 4.2.1.8 requires that stoke time test results shall te compared to the initial reference values or reference values established in j
accordance with paragraphs 3.4 and 3.5. For solenoid-operated valves with reference stroke j
times greater than 10 seconds,14.2.1.8 states that they shall exhibit no more than a 125%
)
change in stroke time when compared to the reference value. For solenoid-operated valves with 35 l
j
i i
reference stroke times less than 10 seconds,14.2.1.8 states that they shall exhibit no more than a i5o% change in stroke time when compared to the reference value. Part 10,14.2.1.9 requires valves with stroke times that do not meet the acceptance criteria of 14.2.1.8 to be retested or declared inoperable. If the valve is retested and also does not meet the acceptance criteria of 1 4.2.1.8, the licensee n sy analyze the data to verify that the new stroke time represents acceptable valve operation. Otherwise the valve is required to be declared inoperable.
Therefore, provided the licensee uses OM-10,14.2.1.8 and all related requirements including the i
corrective actions in 14.2.1.9, relief from trending valve stroke time is covered by the rulemaking.
effective September 8,1992, as described above, and relief is not required. Approval is recommended pursuant to 950.55a 1(f)(4)(iv). Implementation of related requirements is subject to NRC inspection.
3.7 Intake Coolina Water System 3.7.1 Valve Relief Request VR-34, intake Cooling Water to Component Cooling Water Heat Exchangers Butterfly Temperature Control Valves TCV-14-4A and TCV-14-4B Re/let Request: The licensee requests relief from trending valve stroke times quarterly and increasing the test frequency to monthly based on an increase in stroke time relative to the previous test for the intake Cooling Water 30 in. butterfly temperature control valves TCV-14-4A and TCV-14-48 to the Component Cooling Water heat exchangers, as required by the ASME Code,Section XI,1 IWV-3417(a). These control valves regulate the amount of Intake Cooling Water flowing through the Component Cooling System heat exchangers. In the event of failure, these valves will fail open.
Proposed Altemate Testing: Both of these valves will be exercised and fail-safe tested quarterly during which their stroke times will be recorded. However, the valves will not be trended for alert testing. If their stroke times exceed the maximum allowed stroke time, then the valves will be placed out of service.
Ucensee's Basis for Relief: The licensee states that: "These two valves are operated via air signals from their temperature controllers. The valves can be operated by placing their controllers in manual and varying the air signal from the controllers. However, due to the response time of the controllers, the valve stroke times vary from test to test sufficiently to place the valves into alert occasionally. The valve can also be operated by closing the valve manually using the controller and then isolating and then venting the control air signal to the valves. The time it takes to isolate and then vent the control air is dependent upon the operator performing the test. The rate that the air is vented has a direct effect on the valves stroke times. The stroke times vary from test to test sufficiently to place the valves into alert occasionally. Therefore, St. Lucie requests relief from liW-3417(a), the alert trending of valve stroke times."
Evaluation: Section XI,1 lWV-3417(a) states that "If, for power operated valves, an increase in stroke time of 25% or more from the previous test for valves with full-stroke times greater than 10 sec. or 50% or more for valve with full-stroke time less than or equal to 10 sec is observed, test frequency shall be increased to once each month until corrective action is taken.. '
The valves in question, ASME Code Category B valves, regulate the amount of Intake Cooling Water flowing through the CCW heat exchangers. Due to the response time of the controllers, the valve stroke times vary from test to test sufficiently to place the valves into alert occasionally.
36
~ -.- -- - -- -.- -. -
4 l
i-J When testmg is performed manually, the time to isolate and then vent the control air is dependent i
l upon the operator performing the test. The licensee claims that these stroke times also vary from test to test sufficiently to place the valves into alert occasionally.
i
)
}
In rulemaking to 10 CFR 50.55a effective September 8,1992, the 1989 Edition of ASME Section XI was incorporated in paragraph (b) of 6 50.55a. The 1989 Edition provides that the rules for '
(
l~
limitations to OMa 1988 Part 10 associated with stroke time measurements. Section 50.55a 1 inservice testing of valves are as specified in OMa-1988 Part 10. The NRC staff imposed no (f)(4)(iv) provides that inservice testing of valves may meet the requirements set forth in subsequent editions and addenda that are incorporated by reference in paragraph (b) of $50.55a, l
subject to the limitations and modifications listed, and subject to NRC approval. Portions of j
editions and addenda may be used provided that all related requirements of the respective -
l l
editions and addenda are met.
OMa-1988, Part 10,13.3 requires that reference values shall be determined from the results of i
preservice testing or from the results of inservice testing. These tests shall be performed under conditions as near as practicable to those expected during subsequent inservice testing. Part 10, 13.5 permits the establishment of an additional set of reference values if it is necessary or l
l desirable for some other reason, other than as stated in 13.4, i.e., when a valve or its control system has been replaced, repaired, or has undergone maintenance that could affect the valve's j
performance. Therefore, if test conditions for the quarterly tests are different from those at cold shutdown, an additional set of reference values can be established.
j OMa-1988 Part 10 does not require alert trending. Part 10, 1 4.2.1.8 requires that stoke time test results shall be compared to the initial reference values or reference values established in j
accordance with paragraphs 3.4 and 3.5. For air-operated valves with reference stroke times greater than 10 seconds,14.2.1.8 states that they shall exhibit no more than a i25% change in j
stroke time when compared to the reference value. For air-operated valves with reference stroke j
j.
times less than 10 seconds,14.2.1.8 states that they shall exhibit no more than a ISO % change l
in stroke time when compared to the reference value. Part 10,14.2.1.P requires valves with
{
stroke times that do not meet the acceptance criteria of 14.2.1.8 to be retested or declared inoperable. If the valve is retested and also does not meet the acceptance criteria of 14.2.1.8, the licensee may analyze the data to verify that the new stroke time represents acceptable valve l
operation. Otherwise the valve is required to be declared inoperable.
i a
i Therefore, provided the licensee uses OM 10,14.2.1.8 and all related requirements including the 4
corrective actions in 14.2.1.9, relief from trending valve stroke times is covered by the rulemaking, i
e#ective September 8,1992, as described above, and based on meeting later Code requirements, relief is not required. Approval is recommended pursuant to $50.55a 1(f)(4)(iv). Implementation of l
related requirements is subject to NRC inspection.
(
l 4.0 IST PROGRAM RECOMMENDED ACTION ITEMS i-l ASME Section XI inconsistencies, omissions, and required licensee actions identified during the j
review of the licensee's initial interval Inservice Testing Program, Revision 2, are summarized 1
below. The licensee should resolve these items in accordance with the evaluations presented in i
this report.
l l
)
4.1 The IST Program does not include a description of: how the components were j
selected, how testing requirements were identified for each component, or the safety I
37 t
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function of the valves. The review performed for this TER did not include verification that all pumps and valves within the scope of 10 CFR 50.55a and Section XI are contained in the IST Program, and did not ensure that all applicable testing requirements have been identified. The licensee is requested to include this information in the IST Program. The program should describe the development process, such as a listing of the documents used, the method of the basis for categorizing valves, and the method or process used for maintaining the program current with design modifications or other activities performed under 10 CFR 50.59.
Additionally, for each interval, the licensee should maintain an accurate status of the relief requests including their revision and NRC approval.
4.2 As discussed in the TER evaluation for numerous relief requests (i.o., VR-13, VR-18, VR-19, VR-24, VR-33, VR-34), specific portions of OMa-1988, Parts 6 and 10 may be utilized without relief, provided all related requirements are implemented. Approval is recomrnended pursuant to $50.55a f(f)(4)(iv). The use of specific portions of Part 6 or 10 and any refueling outage justifications should, however, be documented in the IST Program. Implementation of related requirements is subject to NRC inspection. (TER Sections 3.2.2, 3.3.2, 3.3.4, 3.4.1, 3.6.1, 3.7.1) 4.3 Section 4.2 of the IST Program, Revision 2 states that the valve test frequency may be extended by 25%, as allowed by the Tecimical Specifications. The extension of test intervals should not be applied to safety and relief valves tested in accordance with the intervals defined in Section XI, because the Technical Specifications do not address these test intervals.
4.4 In Generic Pump Relief Request PR-2, the licensee has requested relief concerning portable instruments used for temperature and speed measurement. When using temporary instruments, the licensee should ensure that the instruments are calibrated prior to use and are traceable to the inservice test records. (TER Section 2.1.2) 4.5 In Pump Relief Request PR-7 for the Diesel Fuel Oil Transfer Pumps, the licensee is calculating pump flow rate based on measuring change in fuel oil storage tank level with respect to pump running time.
This would provide an acceptable level of quality and safety for determining pump flow rate, provided the calculation is properly proceduralized, and the accuracy is within the accuracy required by the Code using direct measurement. The licensee should evaluate the accuracy and repeatability of manually measuring tank level with a tape measure, and ensure that it is within the requirements of the Code and that the calculation is properly proceduralized.
The licensee has proposed new pump flow rate range limits in accordance with Section XI,1 IWP-3210. Although relief is not required, when 1 IWP-3210 is used, the licensee must document the basis for the expanded ranges and the basis that the pump performance does not demonstrate degrading conditions. The basis for acceptable pump performance, in either case, must be related to the pump and not the system, although system requirements must be met. The licensee should include this documentation in the test records. (TER Section 2.2.1) 38
)
i
4.6 in Pump Relief Requests PR-8, PR-11 PR 15 and PR-16, the licensee is proposing to calculate pump suction pressure based on measuring tank or inlet structure levels.
Calculation of inlet pressure based on the measured tank or inlet structure levels provides an acceptable alternative method of determining inlet pressure, provided the calculation is properly proceduralized, and the accuracy is within the accuracy required by the Code using direct measurement. This should be documented in the test records and be available for review.
In the case of the Containment Spray pumps, the licensee should evaluate the feasibility of measuring the pump inlet pressure using the pressure transmitters on pump inlet lines, and use these instruments if practical. (TER Sections 2.2.2,2.3.1, 2.4.1,2.5.1)
Ir Pump Relief Requests PR-12, PR-13, and PR-14, the licensee has requested relief 4.7 from the ASME Code,Section XI,11WP 4520(b), which requires that the frequency response range of the readout system (for instruments used to measure vibration amplituoe) shall be from one-hah' minimum speed to at least maximum pump shaft rotational speed. Specifically, in PR-12 for the Reactor Coolant Charging Pumps, the code-required frequency range is 1.75 Hz to 3.5 Hz. In PR-13 for the intake Cooling Water Pumps, the code-required frequency range is 7.38 Hz to 14.75 Hz. In PR-14 for the Containment Spray System Hydra 2.ine Pumps, the code-required frequency range is 0.875 Hz to 1.75 Hz.
The licensee claims that instruments satisfying these range requirements are commercially unavailable, and that the lowest available response frequency is 10 Hz.
The staff has, however, identified equipment with a frequency response range less than 10 Hz. The licensee should further investigate the procurement of instruments that comply with the Code requirements. Also, the licensee has not discussed the repeatability and accuracy of the instruments to be used. The licensee should additionally evaluate each pump to determine if the pumps are susceptible to degradation mechanisms that result in increased vibration levels at frequencies lower than 10 Hz. Immediate imposition of the Code requirements is impractical due to limitations in the current instrumentation and it would be an undue burden to require the plant to declare the pumps inoperable until the evaluation of subharmonic frequencies and/or available instrumentation could be reviewed. (TER Sections 2.3.2, 2.4.2,2.5.2). Relief is recommended for an interim period of one year or until the next refueling outage, whichever is later to perform the evaluations. The interim relief remains in effect into the next ten-year interval due to begin August 9,1993.
4.8 in Pump Relief Request PR-17 for the Containment Spray Hydrazine Pumps, the licensee is proposing to measure pump flow rate and vibration quarterly but not alert trend the flow rate. At refueling, the pump flow rate and vibration will be measured.
Referring to the licensee's basis, it is assumed that the licensee will not take any corrective actions based on the measured flow rate exceeding the alert or required action values. The licensee should evaluate the establishment of required action ranges for quarterly testing.
The licensee has referenced Section XI 1 IWP 4150 in the relief request, however the licensee has not discussed the possible use of a symmetrical damping device to 39
provide for flow rate averaging. Additionally, the licensee has not discussed the impact or burden of installing flow instrumentation that could be used effectively for the quarterfy test.
Reference to the licensee's Appendix A, Pump Program Table, Revision 2. 08/01/92, indicates that the licensee will not measure the pump inlet pressure or differential pressure. The ASMEl/tNSI C. de OMa-1988, Part 6, Table 3b, requires that pump discharge pressure be measured for positive displacement pumps. The licensee has not provided a basis for not measuring pump differential or discharge pressure.
Provided the licensee determines that there is no practical means of installing flow instrumentation that is adequate for inservice testing purposes, deferring flowrate measurement to refueling outages may be considered acceptable. The licensee j
should evaluate the procurement of damping devices or new flow instrumentation and mearsure and evaluate quarterly pump differential or discharge pressure as well as vibration. Immediate imposition of the Code requirements is impractical due to lack of adequate installed flow instrumentation, and it would be an undue burden to require the plant to declare these pumps inoperable until the availability of new instrumentation could be reviewed. Therefore, it is recommended that relief be granted for an interim period of one year, or until the next refueling outage, whichever is later. The interim relief remains in effect into the next ten-year interval due to begin August 9,1993. In the interim, the licensee should establish acceptance criteria for RPM vs flow rate correlation and measure discharge pressure,if possible.
4.9 in Valve Relief Request VR-13, the licensee is proposing to disassemble and inspect every 10 years each of the four 12 in. discharge line check valves in the lines from the Safety injection Tanks to the Reactor Coolant System. Exercising closed is to be in accordance with the Technical Specifications regarding pressure isolation valves (PlVs).
Disassembly and inspection should only be used if testing with flow is impractica!. The licensee should provide an analysis or test results to show that the nominal 52 seconds stroke time for the SIT discharge isolation motor-operated valves to open is too long to permit sufficient flow to cause the check valves to reach their full-open position. If a full-open position can be reached, the licensee should perform the test with flow to confirm disk position. To substantiate the acceptability of any alternative technique for verifying that the valves are fully open, licensees must, as a minimum, address and document certain items in the IST program, as described in Position 1.
However, if the licensee determines that full-stroke exercising with flow is impractical, the licensee may, as discussed by the NRC in Generic Letter Position 2, perform valve disassembly and inspection as a positive means of determining that a valve's disk will full-stroke exercise open or of verifying closure capability.
The licensee is currently proposing to meet Position 2. Assurance of proper reassembly will be provided by performing a leak test or partial-flow test prior to returning a valve to service following disassembly. However, the licensee intends to inspect each check valve only once in the 10 year Inservice inspection program
. interval. As defined in Position 2, in order to support extension of the valve disassembly / inspection intervals to longer than once every 6 years, i.e., in cases of 40
" extreme hardship,' licensees should perform a review of the installation of each valve addressing the 'EPRI Applications Guidelines for Check Valves in Nuclear Power Plants' for problematic locations. The licensee should justify the extreme hardship, including a discussion on why non-intrusives cannot be used.
Additionally, the licensee states that valve will be leak tested or partial-flow tested following disassembly, if possible, partial valve' stroking quarterly or during cold shutdowns, or after reassembly, must be performed.
Relief is granted per Generic Letter 89-04, Position 1, to full-stroke exercise the valves open with less than the accident flow rate, provided all criteria in Position 1 are met. If the licensee determines that full-stroke exercising is impracbcal, relief is granted per Position 2 to disassemble / inspect these check valves, provided the licensee meets all the criteria inJ'osition 2, including reviewing the installation of the valves, demonstrating extreme hardship, and partial-stroke exercising following reassembly ~
and at cold shutdown if practical.
With respect to exercising the valve closed. OMa-1988 Part 10,14.3.2.2 allows full-stroke exercising that is not practicable during operation or cold shutdown to be deferred to refueling outages. Relief.to use the Technical Specification requirements is not required pursuant to $50.55a 1(f)(4)(iv), provided the licensee implements 14.3.2.2 and all related requirements, including Part 10,14.3.2.2(h) and 16.2. Implementation of these related requirements is subject to NRC inspection. (TER Section 3.2.2) 4.10 in Valve Relief Request VR-14, the licensee is proposing to partial-stroke exercise at cold shutdowns and refueling outages the four 12 in. Safety injection check valves which open to provide flow paths from the safety injection headers to the RCS and close to isolate the headers from the high pressure of the reactor coolant system.
The licensee should evaluate if the va'ves will achieve a full-open position with the proposed reduced test flow rate of 3,000 GPM. If a full-open position can be reached, the licensee should perform the testing with flow. The use of alternate techniques, such as non-intrusive techniques, to verify that valves will fully open is acceptable, as -
discussed in Generic Letter 89-04, Position 1, if the valves cannot be full-stroke exercised, the NRC defined an acceptable tuernative to the full-stroke exercising requirement in Position 2, wherein it is stated that the NRC staff position is that valve disassembly and inspection can be used as a positive means of determining that a valve's disk will full-stroke exercise open or of verifying closure capability.
The licensee is currently proposing to meet Position 2. Assurance of proper
- reassembly will be provided by performing a leak test or partial-flow test prior to returning a valve to service following disassembly. However, the licensee intends to inspect each check valve only once in the 10 year Inservice inspection program interval. As defined in Position 2, in order to support extension of the valve disassembly / inspection intervals to longer than once every 6 years, i.e., in cases of
' extreme hardship,' licensees should perform a review of the installation of each valve addressing the 'EPRI Applications Guidelines for Check Valves in Nue! ear Power 41
Plants' for problematic locations. The licensee should also include a discussion on why l
non-intrusives cannot be used.
Additionally, the licensee states that the valve will be leak tested or partial-flow tested following disassembly, Position 2 requires that, if possible, partial valve stroking quarterly or during cold shutdowns, or after reassembly, must be performed.
Relief is granted per Generic Letter 89 04, Position 1, to full-stroke exercise the valves open with less than the accident flow rate, provided all criteria in Position 1 are met. If the licensee determines that full-stroke exercising is impractical, relief is granted per Position 2 to disassemble / inspect these check valves, provided the licensee meets all the criteria in Position 2, including reviewing the installation of the valves, demonstrating extreme hardship, and partial-stroke exercising fol;owing reassembly and at cold shutdown if practical.
With respect to exercising the valve closed, verification that a valve is in tne closed position can be done by visual observation, by an electrical signal initiated by a position-indicating device, by observation of appropriate pressure indication in the j
system, by leak testing, or by other positive means. The licensee does have instrumentation to continuously monitor upstream pressure. Based on the Technical Specifications, it appears that following the partial-stroke exercise at cold shutdowns, verification that the valves have closed will be performed and relief would not be required. The licensee should exercise these valves closed at cold shutdowns or revise the request accordingly. (TER Section 3.2.3) 4.11 in Valve Relief Request VR-18, the licensee is proposing to verify the Makeup Water Supply containment isolation valve (CIV) closed at least once every two (2) years, in conjunction with the Appendix J leak testing program. Valve Relief Request VR-19 is a similar request for the Instrument Air Header CIV.
The relief requested by the licensee is covered by rulemaking, effective September 8, 1992, and relief is not required, provided that the proposed alternative testing is performed at least during every refueling, even if the refueling interval is less than 2 years, and that OMa-1988 Part 10,14.3.2.2 and all related requirements are implemented. Approval is recommended pursuant to 50.55a 1(f)(4)(iv).
Implementation of related requirements is subject to NRC inspection. (TER Sections 3.3.2, 3.3.3) 4.12 in Valve Relief Request VR-24, for the check valves in the Hydrazine Pump discharge to the Containment Spray System pump suction, the licensee is proposing to flow test these valves at every refueling.
Since each of the hydrazine pumps discharge through its check valve into the suction piping of its corresponding Containment Spray pump, the licensee states to flow test the check valves, each Containment Spray pump must be operated and flow recirculated back to the Refueling Water Tank (RWT). The licensee also states that continued testing would build up concentration of hydrazine in the RWT and deplete the level in the HST. The licensee should explain specifically why hydrazine buildup in the RWT is detrimental and could not be reduced or removed. Also, the licensee has not explained why the level of hydrazine in the HST could not be restored.
42
Additionally, upon review of the flow diagrams it appears that the valves could be tested at cold shutdowns without operating the containment spray pumps by isolating the containment spray pumps manual suction and discharge valves and collecting the hydrazine through the 1 in. test connection at the pumps suction. The licensee should consider this test configuration.
OMa-1988 Part 10,14.3.2.2 allows full-stroke exercising that is not practicable during plant operation or cold shutdowns to be deferred to refueling outages. Accordingly, l
relief is not required, provided that the licensee clarify the impracticality of testing caused by buildup of hydrazine in the RWT and the depletion of the level in the HST, and determines that testing using the 1 in. pump suction drain connection is impractical. Approval is recommended pursuant to 950.55a 1(f)(4)(iv). Implementation of related requirements is subject to NRC inspection. (TER Section 3.4.1) 4.13 in Valve Relief Request VR-26, for the Diesel Air Start System flow control and solenoid valves, the licensee is proposing that these valves will be exercised in conjunction with testing of the emergency diesel generators. Both the 2A and 28 diesel generators will be started each month. Every 6 months, these 16 air start system valves will be tested for proper operation by observing the operation of each associated pair of air start motors. The stroke timas of the individual valves will not be measured.
Although the valves' stroke times cannot be measured by conventional means, the stroke times can be measured indirectly by monitoring diesel start times or by non-intrusive methods, e.g., by using acoustic or diagnostic systems. Using diesel start times, any degradation in the valves' stroke times would result in longer diesel start times. A maximum limiting start time should be specified that is less than or equal to the Technical Specification requirement. If this limiting start time is exceeded due to degradation or failure of the air start system valves or motor operators, they should be declared inoperable and repaired or replaced.
With respect to test frequency, the licensee has not adequately demonstrated any undue burden caused by quarterly testing. Further information regarding the reason why a 6 month test interval provides an acceptable level of quality and safety should also be provided. It is recommended that interim relief be granted. In the interim, the i
licensee should evaluate the establishment of a maximum limiting start time or some other method to detect degradation and the performance of testing in accordance with the Code required frequency.
Additionally, the licensee should review the Code classification of these valves. As discussed in Question 54 of the minutes of the public meeting on Generic Letter 8944, diesel generator air start systems are not typically Class 1,2, or 3, and are, therefore, not required by 10CFR50.55a to be tested in accordance with Section XI. If the licensee determines that these valves are not required to be Class 1,2, or 3; relief from Section XI is not required. (TER Section 3.5.1) 4.14 Valve relief requests VR-8, to and 12 state that full. flow exercising at each refueling outage " satisfies the requirement of Generic Letter 89-04, Position 1." Position 1 addresses alternate full-stroke exercising methods when full-flow exercising is impractical. Position 1 does not address afternate test frequencies, and therefore the Generic Lo*ter does not grant relief from testing valves quarterly or at cold shutdowns.
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However, OMa-1988, Part 10,14.3.2.2 allows testing that is impractical during plant operation and cold shutdowns to be deferred to refueling outages. Therefore, provided that the licensee uses 14.3.2.2 and all related requirements, including 16.2 which requires documentation of the justification for deferring testing, relief is not required. Approval of the alternative is recommended pursuant to $50.55a 1(f)(4)(iv).
As discussed above, implementation of related requirements is subject to NRC inspection.
4.15 Relief Requests VR 17 and 25 propose testing containment isolation valves closed at cold shutdowns. This complies with the rec,uirements of Section XI and relief is not t
required. The basis for testing at cold shutdowns should however be documented.
5.0 REFERENCES
1.
NRC Regulatory Guide 1.147, " Inservice Inspection Code Case Acceptability, ASME Section XI, Division 1," Revision 9. April 1992.
2.
ASME Boiler and Pressure Vessel Code,Section XI, Rules for Inservice inspection of Nuclear Power Plant Components,1980 Edition including Winter 1980 Addenda.
)
3.
St. Lucie t.' nit 2 Technical Specifications.
4.
ASME/ ANSI OMa-1988, Part 6, " Inservice Testing of Pumps in Ught-Water Reactor Power Plants."
5.
ASME/ ANSI OMa-1988, Part 10, " Inservice Testing of Valves in Ught Water Reactor Power Plants."
6.
10CFR50.55a 7.
Standard Review Plan, NUREG 0800, Section 3.9.6, inservice Testing of Pumps and Valves, Rev. 2, July 1981.
8.
NRC Generic Letter 89-04, " Guidance on Developing Acceptable Inservice Testing Programs," April 3,1989.
9.
Minutes of the Public Meetings on Generic Letter 89-04, October 25,1989.
10.
Supplement to the Minutes of the Public Meetings on Generic Letter 89-04, September 26,1991.
11.
" Initial Ten-Year Inservice Inspection Interval inservice Testing Program-Revision 2,"
D.A. Sager (FP&L) to USNRC, September 15,1992 (L-92-247).
12.
" Inservice Test Program Relief Requests VR 18 and VR-30-Check Valve Testing,"DA Sager (FP&L) to USNRC, January 13,1993 (L-9310).
13.
" Inservice Testing (IST) Program Relief Request," D.A. Sager (FP&L) to USNRC, February 25,1992 (L-92 38).
44
l 14.
" Inservice Test Program Temporary Relief Request 4 heck Valve inspection," D.A.
Sager (FP&L) to USNRC, May 27,1992 (L-92-160).
15.
" Revision to the St. Lucie Unit 2 Pump and Valve Inservice Test Program Plan," W. F.
Conway (FP&L) to USNRC, April 4,1988 (L-88-158).
16.
" Safety Evaluation - Inservice Testing (IST) Program, St. Lucie Unit 2 TAC No.
M82931, USNRC to FP&L, April 16,1992.
17.
" Safety Evaluation - Inservice Testing (IST) Program, St. Lucie Unit 2 TAC No. 81282,"
USNRC to FP&L. December 5,1991.
18.
"St. Lucie Unit 2-Reliefs from Parts of ASME Code Section XI, TAC No. 67832 "
USNRC to FP&L, October 2,1989.
j i
19.
" Relief from Parts of ASME Code Section XI, TAC No. 56707," USNRC to FP&L, January 13,1986.
1 i
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.