ML18082B237
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vDOCKET FIL\\E ( 50-272Y 311)
ASB READING--
SEP 11 1980 R P,Cbeck
--... MEr10RA~l0tJMFOR:***Robert L. Tedesco, Assistant Director for'Licensing, DOL FROM:
SUBJECT:
Thomas M. Novak, Assistant Director for Operating Reactors9 DOL Paul S. Check, Assistant Director for Plant Systems, DSI SALEM NWCLEAR GENERATING ST!TION, UNITS 1 81 2 - SAFETY EVALU1HION-REPORT SUPPLEMENT - INPUT ON THE IMPLEMENTf,TION.
OF RECOMMENDATIONS FOR THE AUXILIARY FEEDVIATER SYSTEM Enclibsure 1 provides the Auxiliary Systems Branch (ASB) Supplement to the subject Safety Evaluation Report (SER) input. Ihis supplement updates long -
term recommendation i terns GL-2 and GL.:4.
In the case of recommendation GL-2, the licensee has proposed a different method of implementing our recommenda-tion thati that which was discussed in the SER input.
We have acceptod the licensee's,new proposal and conclude that recommendation GL-2 has been -
satisfactorily resolved.
In* the case of recommendation GL-4, the licensee has provided sufficient data to demqnstrate that the service water system,
\\tJhich is saline, can be utilized for providing feed to the steam generators for 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />) in the event the auxiliary feedvmter storage tank becomes incapacitated due to impact by tornado missile~. He conClude that recommen-dation GL-4 has been satisfactorily resolved.
Our review is not cmnplete for the following tvm items~ which were discussed in our SER input:
- 1. Additionai Recommendation 3 - The safety grade design (long term require-ment) for auxiliary feedwater flow indicatfon is still under staff reviev1.
Our evaluation will be presented in a separate supplement.
This is a dated requirement.
- 2.
Long Term Recommendation GL The safety grade design (long term require*-
rnent) for auxiliary feedwater automatic initiation sifmals and circuits is still under staff review.
Our evaluation will be presented in a separate supplement~. This is a dated requirement.
Original Signed bY.
Paul S. Check
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Paul S. Check, Assistant Di rector
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p 80.0925'0 ~/3 f©or Plant Systems
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Division of Systems Integration
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U.U. GOVl!RNMENT PRINTING OP'... ICB: 1971 - 269
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- R-.- Tedesco
~i T. Novak cc: o.* Ross D. Eisenhut
- 0. Parr R. Satterfield T. Speis So Varga
- A. Schwencer l'l. Ross J. Kerri gaii F. Orr B. Mann
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SEP 1 J 1980
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. me PORK_ 318 (9*76) NRCM: 0240
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Supplement to the Safety Eva1 uation Report Input Salem Nuclear Generatfrig Station, Units l & 2 Implementation of Recomnendations For Auxiliary Fe.edwater System
- 1.
Recorrmendation GL-2 -"Licensees \\vit!t plants in *.othich a11 (primary and alternate) water supplies to the AFW systems pass through valves in a single flaw path should install redundant parallel flaw paths (piping and valves).
L fcensees '"'i th pl ants in which the primary AFW system water supply passes through valves in a single flow path. but the alternate AFW system water supp1lies connect to the AFW system pump suction piping downstream of the above valve(s}, should install redundant valves parallel to the above valve(s} or provide automatic opening of the valve(s} from the alternate water supply upon law pump suction pres-sure.
- The licensee should propose Technical Specifications to incorporate I I appropriate periodic inspections to verify the valve positioAs.
The AFWS pump suction design includes a corrmon suction pipe which routes the normal auxiliary feedwater pump supply from the auxiliary feedwater -
storage tank (AFST) to 3 individual pump suction lin2s. A manual gate valve is located in the common suction pipe (lAFl for Unit l and 2 AFl for Unit 2}. This valve is installed in the inverted position. Inadvertent closure of this valve would isolate the nonnal pump suction flow path.
l The licensee proposed a positive means of preventing valve closure.
This involves radiographing the valve to ensure an open flaw path, drilling
\\ and pinning the yoke bushing and stem in the open position, removal of the handwheel, and cutting off the exposed section of the valve stem.
We concur with the licensee's proposal except for removal of the stem.
We. require that the stem not be removed in order to provide visual evidence that the valve is open.* We will require that the Office of Inspection and Enforcement verify the radiographed valve position and the valve modifications.
We conclude that recommendation GL-2 is adequately met~. and therefores acceptable.
- 2.
Recommendation GL "Licensees having plants with unprotected normal AFW system 'Nater supplies should evaluate the design of their AP.. ! sys-terns to determine if automatic protection of the pumps is necessary following a seismic event or a tornado.
The time available before pump damage, the alarms and indications available to the control room operator, and the time necessary for ~ssessing the problem and taki.n*;
action should be considered in detennining whether operator action can be relied on to prevent pump damage:
Consideration should be given to providing pump protection by means such as automatic switch-over of the pump suctions to the alternate safety-grade source of.
water, automatic pump trips on low suction pressure, or upgrading the normal* source of water to meet seismic Categor/ ! and tornado protec-tion requirements."
(Note:
this recormiendation was not included in our September 21, 1979.requirements letter.)
The primary water supply for the AFWS is maintained in the 220,000 ga 11 on auxi 1 i ar;l feedwater storage tank (AFHST}.
The water inventory is sufficient for about 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of.decay heat removal.
The AP.~ST is seismic Category I but not tornado missi1e resistant. Alternative water supply sources fnclude the demineralized water storage tanks, and the fire protection and domestic water storage tanks, none of *.vhich are safety grade.
!n the event tlie AP.MST is incapacitated by a tornado
- missile strike, the seismic.category rand tornado.missile resistant*
service '.'later system can be lined up to supply.auxiliary feedwater by installation of a spool piece.
In NUREG-0517, Salem Unit 2 SER, Supplement #4, ~twas concluded that a reasonable time estim~te from the loss of tne AFWST to completion
- of the spoo 1 piece connection is 53 minutes.
This ti me i nterva 1 is
_acceptable based on an estimate of 70 minutes \\-tithout cooling before the core begins to be uncovered. !tis concluded "that the appli-cants have the capability of lining up the service water system to the auxiliary feedwater pumps in a time interval *.vnich assures that the
_core is adequately cooled in the eyent Qf loss o_f an normal. *~ater oackur system." Since the units ara idantical, this conclusion should apply to Sal.em Unit 1 also.
Subsequent to publication of this supplement, tHo additional proble~ areas were identified in this area.
The first concerns the possible harm-fol effects of utilizing the service water. which under nonnal conditions has a
.. salt concentration approximately half that of seawater.
Since, subsequent to a*
postulated incident, the AFWS would have to be utilized for decay heat removal and cooldown until the residual heat removal system (RHRS) can be cut-in, there was some concern that sufficient salt could solidify to decrease steam generator heat transfer to unacceptable levels and also cause flow blockage.
Another concern was the poss1bility of una ccep tab 1 e corrosion during th; s time peri ad.
The 1; censee. has sub-mitted ani.analysis on this subject in i.ts July 1, 1980 letter~- followed by
- ~".!,;i-l:~~"al infomation in a September 3, 1980 letter.
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.*. _, The licensee's submittal assumed seawater salt concentrafion, which conserva-tively bounds *the Delaware River sa1 t concentrations for all conditions.
- The licensee, in FSAR Amendment 43, has indicated that auxiliary feedwa.ter was required for 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> after reactor trip in order to reach the residual heat removal (RHR) system pressure/temperature cut-in point. At the end *of 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br />, the sodium chloride concentration was calculated to be 31.5%, which is well within the solubility _l_imit for both '..oom temperature and_operating temperature.
Some precipitation of calcium sulfate may occur but this would not signifi-cantly affect the steam generator heat transfer characteristics.
Based on the licensee's submittal, we concludr: that the steam generators could operate for 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> with salt water feed without significant degradat"ion of the steam generator shell side heat transfer, and. that flow path clogging by 'salt,deposition would not be expected. With regardto corrosion
.effects, we conclude that salt corrosion effects would not prev_ent theheat removal function of the steam generators for the postulated scenarios, however, we recognize tha!t corrosion effects from 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> of operation with a sal _ine solution most likely would deteriorate the secondary side of the steam generator for subsequent operation.
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.* The second concern involves installation of the spool piece during or right after a tornado, when many actions might have to be taken at the same time...
~t the June 18 meeting on Salem Unit 2, the licen-see made a commitment to modify plant procedures to require ~pool piece 1nsta1lation in the event of a tornado warning.
We, therefore, consi7qer--1;-ha-t-tl'1.e-l-i-i;ensee-has_a_deq_U_a_tely_met this concern.
ihe licensee, in its June 27 letter, stated that the Salem Unit 2 iechnical Specifications contain* annual surveillance requirements to verify that the service *t1ater spool piece is onsite.
~~e *,o1ill require that the Salem Unit 1 iechnical Specifications contain the same requirements.
~!e conclude that reco1T111endation GL-4 1s adequately met, and therefore; acceptable.