ML19256G164

Forwards Response to NRC 790810 Request for Info Re Possible Draining of Spent Fuel Storage Pool Following Pipe Failure, Per SEP Topic IX-1, Fuel Storage.

ML19256G164
Person / Time
Site:	Oyster Creek
Issue date:	12/14/1979
From:	Nagai Y JERSEY CENTRAL POWER & LIGHT CO.
To:	Fletcher M Office of Nuclear Reactor Regulation
References
NUDOCS 7912270544
Download: ML19256G164 (5)

Text

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Jersey Central Power & Ught Company Madison Avenue at Punch Bowl Road Mornstown, New Jersey 07960 (201)455-8200 December 14, 1979 Mr. Mike Fletcher Systematic Evaluation Program Branch Division of Operating Reactors U. S. Nuclear Regulatory Commission Washington, D. D. 20555 Re: Oyster Creek Nuclear Generating Station SEP Topic IX-1 Fuel Storage

Dear Mr. Fletcher:

Your telecopied letter of .\ugust M, 1979, transmitteu four questions concerning the subiect topic.

Our responses are provide ~ in the enclosed attachment.

Very truly yours,

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l' / ' ' /,

j1- - . .

,/ Soshito Nagai cc: T. Wambach - NRC T. E. Tipton J. Knubel W. R. E:hmidt M t\

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.ersey Certra! Pcwer & L'grr Ccracacy :s a Mer-ter of tre General ~ .c Ut*t'es System 782ss7o3%'

e OYSTER CREEK NUCLEAR GENERATING STATION SEP Topic IX-1 Fuel Storage Question 1: Can the failure of any piping system result in draining the spent fuel pool below the level of the top of the stored fuel (consider siphoning) ?

Response . The fuel pool has n'o installed drains and the fuel-pool cooling system will not lower the pool water below weirs. Fuel-pool water flows over the weirs through two surface skimmers, both at the north side of the pool into surge tanks. The pool water is pumped from the surge tanks through heat exchangers, a filter, a demineralizer and returned to the fuel pool through two return diffusers at the bottom of the pool in the southeast and south-west corners. Each return pipe has a check valve at the pool to prevent siphoning of the pool water with these dip lines.

The pool skimmer weirs are about 3 inches below the pool water level. The normal water level in the fuel pool is approximately 23 feet above the top of the spent fuel to provide sufficient shielding for normal building occupancy by operating personnel .

The pool is completely lined with stainless steel. Leakage drains in the concrete pad under the floor lining can be used to detect pool-lining leaks. A manually operated valve in the drain line provides the capability to prevent fuel pool leakage should the liners fail.

Question 2: What instrumentation and alarms are associated with the spent fuel pool?

Response The pool has a level switch with high and low-level annunciation.

Various other annunciators are provided for the fuel pool cooling system and they are listed in Table 3.2-12 of the System Description for the Oyster Creek Nuclear Generating Station. The Table 3.2-12 is attached to this letter (ATTACHMENT A) .

Question 3: List all the sources of makeup water to the pool (include

" DAMAGE CONTROL SEASURE" sources such as Fire Hoses) . Provide comments regarding the ability of these sources to survive a seismic event (SSE).

Response >bke-up water to the fuel pool comes from the Condensate Transfer System and the Demineralized Water Transfer System. We have no analysis to show that these systems can survive a seismic event (SSE) though a recent analysis indicates that the Condensate Storage Tank is designed to meet the Seismic Class I qualification.

The spent fuel pool is designed for the Seismic Class I structure.

Since the pool has no installed drains and siphoning through the fuel-pool cooling system is prevented, it is highly unlikely that the water level in the pool wculd decrease to an unsafe level following a seismic event.

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Question 4: Discuss the ability of the plant systems and procedural controls to detect a low fuel-pool level following a seismic event.

Response : As it is indicated in our response to Question 2, a low water level annunciator is provided for the fuel-pool. liowever, it is not built for Seismic Class I design criteria. There are no procedural controls to detect a low fuel-pool level following a seismic event.

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~ 251 e -- 'ucl-Feel Cec:ir ' h L; r.t r a . cnc Instru=entation Sensine Instru=ent Actuates LS 1707-53 1. Annunciator G on Panel 3F: FUEL POOL HIGH LEVEL; set point at 118.33 fe elevation

2. Annunciator G on Panel 3F: FUEL POOL LOW LEVEL; set point at 118.125 ft elevation LS 1707-54 Alar: light near fuel pool for high level in surge tank; set point at 107 ft, 2 in. elevation equal to 250 ft3 surge volume in each tank LS 1707-55 1. Annunciator G on Panel 3F; SKI.9:ER SURGE LOW LEVEL; set point at 99.67 ft. eleva-tion, equal to 100 f 3 water volu=e in each tank

2. Annunciator G cn Panel 3F: SKIMER SURGE LGW-LOW LEVEL; set point at 97 ft 6 in. elevation, equal to 50 ft3 water volu e in each tank

3. Trips both fuel pumps on ski =ser low-law level to protect pu=p; set poing at 97 ft 6 in. elevation, equal to 50-ft water volume in each tank FIS 1707-51 1. Annunciator G on Panel 3F: FUEL POOL GATES HIGH LEAK; set point at 1 gp=

2. Flow indicator and alarm light near fuel pool, for excessive leakage through fuel gate; set point at 1 gpm LI 1707-58 Level indicator, located near fuel-pool heat ex-changers, for reactor-cavity water level; pres-sure gauge with 0-125-f t scale, used during cavity filling and draining FS 1707-56 1. Annunciator G cn Panel 3F: REFUEL SE.M.

HIGH LEAK; set point at 0.5 gp=; used to detect leakage through reactor vessel to dry-well bellows seal

2. Alarm light near fuel pool for refuel seal leak; set point at 0.5 gpm 1645 066 L 134

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Control and Instrumentation icentinued)

PS 1707-57A, -B Trips fuel pool pump A or 3 on low pump suction pressure, to protect punp; set point at 9.1 psig to assure adequate NPSH PIS IN04A, -B 1. Fuel pump discharge pressure indicators at pu=ps

2. Alar = ligh t near fuel pool for low pump dis-charge pressure; set point at 130 psig TE 1707-52A, -B Te:perature recorder 270S for fuel-pool cooling system te perature fro: heat exchangers. This same recorder is used for the shutdown cooling system.

dPIS IM06 1. Annunciator on panel in Kadwaste Building for high pressure drop across fuel-pool fil-ter; set point at 30 psid

2. Differential pressure indicator, 0-100 psid FI IM 199 Tuel 7ool-filter flow indicator ic:2ted near fuel pool pumps; range, 0-600 sp=

FRCS IM 105 1. Annunciator on panel in Radwaste Building for low fuel-pool filter ficw; set point at 250 gp=

2. Trips both fuel pool pumps, filter-aid pump and filter outlet valve (NV 102) on low fuel-pool-filter ficw, to keep dropped filter-cake caterial out of fuel pool; set point at 250 gp: (equivalent to 2 psid across clean filter)

3. Flow recorder 0-600 gpm dPIS IM 167 1. Annunciator on panel in Radwaste Building for high pressure drop across fuel-pool de=ineral-1:er; set point at 30 psid

2. Differential pressure indicator, 0-100 psid CI IM 48 1. Conductivity indicator on panel in Radwaste Building, 0-10 u=ho/cm

2. Annunciator on panel in Radwaste Building from CRS IM 12 for high-conductivit'y fuel-pool desineralizer effluent; set point at 1.0 unho/cm 1645 067 .

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