ML19326C140

Tech Spec 9 Re Borated Water Recirculation Pump

ML19326C140
Person / Time
Site:	Arkansas Nuclear
Issue date:	10/07/1976
From:	ARKANSAS POWER & LIGHT CO.
To:
Shared Package
ML19326C135	List: ML19326C134 ML19326C140 ML19326C144
References
NUDOCS 8004210641
Download: ML19326C140 (11)

Text

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G through the pond before discharging to the Dardanelle Reservoir. Any excess runoff is discharged by use of a spillway, which is designed to accomodate one half the probable maximum precipation at maximum flow capacity, based on a total rainfall of 19.5 inches in 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.

The 26-spillway is a slab on grade design, which rests on the side slopes of the 9.5 r, pond and consequently will remain stable under a concurrent OBE condition.

9.6 The average annual rainfall is more than sufficient to offset whatever minor leakage and normal evaporation may occur in the ' pond.

The pond was excavated using conventional earth moving equipment. The concrete Class I intake and discharge structures are keyed into the existing clay and backfilled using an impervious material to form a seal at these points.

9.4 SPENT FUEL COOLING SYSTE?!

9.4.1 DESIGN BASES The spent fuel cooling system is designed to maintain the water qu".'. tty and clarity and to remove the decay heat from the stored fuel in the spent fuel pool.

It is designed to maintain the spent fuel pool water at approximately 120F, with a heat load based on removing the decay heat generated from 10 batches of fuel assemblies which have been irradiated for 930 days and cooled from 150 hours0.00174 days <br />0.0417 hours <br />2.480159e-4 weeks <br />5.7075e-5 months <br /> to 9 years.

In meeting the foregoing design bases, the system has the capability of maintaining the spent fuel pool at approximately 150F while removing the 28 total decay heat load from the following combination of stored fuel assemblies:

1/3 core irradiated for 930 days and cooled for a.

e

<ea rs and 100 days, b.

1/3 core irradiated for 930 days and cooled for 5 years and 100 days.

1/3 core irradiated for 930 days and cooled for 4 years c.

and 100 days.

d.

1/3 core irradiated for 930 days and cooled for 3 years and 100 days.

1/3 core irradiated for 930 days and cooled for 2 years e.

and 100 days, f.

1/3 core irradiated for 930 days and cooled for 1 year and 100 days, g.

1/3 core irradiated for 930 days and cooled for 100 days.

h.

1/3 core irradiated for 720 days and cooled for 150 hours0.00174 days <br />0.0417 hours <br />2.480159e-4 weeks <br />5.7075e-5 months <br />.

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1/3 core irradiated for 410 days and cooled for 150 hours0.00174 days <br />0.0417 hours <br />2.480159e-4 weeks <br />5.7075e-5 months <br />.

j.

1/3 core irradiated for 100 days and cooled for 150 usurs.

In addition to its primary function, the system provides for purification of the spent fuel pool water, the fuel transfer canal water, and the contents of the borated water storage tank in order to remove fission and corrosion products and to maintain water clarity for fu'el handling operations. Se system also provides for filling the fuel transfer canal, the incere instrumentation tank, and the cask loading area from the borated water storage tank.

9.4.2 SYSTEM EESCRIPTION 2e spent fuel cooling system shown in Figure 9-11 provides cooling for the spent fuel pool to remove fission product decay heat energy.

Design data are shown in Table 9-9.

Major components of the system are summarized in 27 Table 9-9 and briefly described below.

Spent Fuel Coolers 2e spent fuel coolers are designed to maintain the temperature of the spent fuel pool as noted in Section 9.k.l.

Spent Fuel Pool Circulating Pumps 27-9.h0 The two spent fuel pool circulating pumps take su'etion from the spent fuel pool and recirculate the fluid back to the pool after passing through the coolers. Part of the flow is diverted through the demineralizer and filters arranged in various combinations depending on conditions. During refuehng operations these pumps are also used for filling the fuel 27-9.h0 transfer canal and incore instrumentation tank with borated water from the borated water storage tank.

Spent Fuel P g 27-9.h0 The spent fuel pump located near the bottom of the cask loadirig pit acts as a booster pump to supply suction to the spent fuel pool circulating pumps. In this manner water from the transfer pit is pumped to the borated 28 water storage tank. It is employed to pump down the pit for dry handling of the spent fuel shipping cask.

Spent Fuel Coolant Demineralizer he spent fuel coolant demineralizer vill process appro.~imately one-half of the spent fuel pool volume in 2h hours.

Spent Fuel Coolant Filters he spent fuel coolant filters are designed to remove particuate catter from the spent fuel pool vater. They are sized for the same fl,v rate as the demineralizer.

9-16 Amendment No. 28 August 18, 1972

f-i 16rEi~ed Water ReH rdGTaMoW Pumo

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l This pump removes water from the borated water storage tank for demineraliza'-

tien and filtering. The pump may also be used for demineralizing and filter-ing the water in the fuel transfer canal during a transfer of fuel.

If both spent fuel coolant pumps are unavailable for use, it may also be used for e=ptying the fuel transfer canal.

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9.h.2.1 Modes of Operation 9.h.2.1.1 Normal Operation 4

The normal operation of the spent fuel cooling system serves two rmin functions.

Thejfirst is to maintain the pool water;at temperatures of approximately 120 F or less with 10 batches of stored fuel at expected operating histories and with f

both pumps and both coolers operating. The second function is to orovide puri-fication of the spent fuel pool coolant! for clarity during fuel hrs..dling opera-tiens.

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The' first ft.nction is accomplished by recirculeH p w rt

• il coolant water frcm the spent fuel pool through the pumps and coolers and back to the pool..

The. spent fuel coolant pumps take suction from the spent fuel pool and deliver the water through the tube side of two coolers arranged in parallel back to the' pool.

A blypass purification loop is provided to maintain the purity of the water :in l

theispent fuel pool. This loop is alsol utilized to purify the water in the borfted water storage tank following rsfueling, and to maintain clarity in lthe fuel1transfercanalduringrefueling. Water from the borated water storage, tank or fuel transfer canal can be purified by using the borated water reci.r-cul'ation pump.

f 9.j.2.1.2 Refueling Conditions Normally a maximum of 10, batches. of the spent fuel assemblies will be stored in the pool. When 10, batches are stored, assuming the conditions in Section 9.4.1, two pumps and two coolers will maintain pool coolant at approximately 120 F.

One pump and one cooler will maintain pool coolant at approximately 145F.

When 3-1/3 cores are stored under the e'onditions of section 9.h.1 due to the l

assumed unloading of a ecmplete reactor core, two pumps and two spent fuel l coolers will maintain the spent fuel storage cool temperature at approximately 150 F.

If both a pump and a cooler are assu::.eu.o be unavailable when this' storage condition exists, the water temperature would eventually rise to ap-proximately 210 F, although considerable time would be required to heat thq large spent fuel pool to this temperature. If all cooling is lost, the time reiuired for the spent fuel pool to reach 212 F for the specified quantitie's and conditiens of stored fuel is as follows:

Three.and one-third cores s19 hours2.199074e-4 days <br />0.00528 hours <br />3.141534e-5 weeks <br />7.2295e-6 months <br /> Three and one-third cores s5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> (with full core discharge)

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9.6 FUEL llANDLING SYSTDI 9.6.1 DESIGN BASES 9.6.1.1. General System Function The fuel handling system is designed to provide a safe, effective means of transporting and handling fuel from the time it reaches the plant in an unir-radiated condition until it 1 caves the plant after post irradiation, cooling.

The system is designed to minimize the possibility of mishandling or malopera-tions that could cause fuel assembly damage and/or potential fission product release.

The reactor is refueled with equipment designed to handle the spent fuel as-semblies under water from the time they leave the reactor vessel until they are placed in a cask for shipment from the site. Underwater transfer of spent fuel assemblies provides an effective, economical, transparent radiation shicid, as well as a reliable cooling medium for removal of decay heat.

Borated water ensures subcritical conditions during refueling.

9.6.1.2 New Fuel Storage Area The new fuel storage area is a separate and protected area for the dry storage of new fuel assemblics in the fuel storage and handling area.

The new fuel storage area is si:cd to accommodate 72 new fuel assemblies. The new fuel assemblies are stored in racks in parallel rows having a center-to-center dis-tance of 21 inches in both horizontal directions. This spacing is sufficient to maintain a keff of less than 0.9, even if the space were flooded with un-borated water.

9.6.1.3 Spent Fuel Storage Pool The spent fuel storage pool, located in the fuel storage and handling area, is a reinforced concreto pool lined with stainless steel.

The pool is sized to accommodate 590 spent fuel assemblies. This allows the concurrent storage of a full core of irradiated fuel assemblies (177) and seven batches of spent fuel assemblies (about 413). One additional space is available for storage of a failed fuel assembly and its special container.

The spent fuel assemblics are stored in racks in parallel rows having nominal center-to-center distance of 13.5 inches in both horizontal directions. Control rod assemblics requiring removal from the reactor are stored in the spent fbel assemblies.

Adjacent to the spent fuct pool are two smaller pools. One pool contains the fuel transfer mechanism, the other pool is a loading area for a spent fuel shipping cask. These two pools are connected to the main pool by short water channels and may be isolated from the spent fuel pool by water-tight gates.

' These smaller pools may then be pumped down to allow dry handling of the spent "uel shipping cask or maintenance of the fuel transfer mechanism.

9.6.1.4 Fuel Transfer. Tube A hori:ontal tube is provided to convey fbel between the reactor building and the fuel storage pool. This tube contains tracks for the fuel transfer 9-22 l

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terTuel transfer mechanism is an~ underwater' carriage that~ runs crrtracic1xtmT~

ing! from the spent fuel storage pool thiough the transfer tube and into the-reactor building. A rotating fuel basket is mounted on one end of the fuel' transfer carriage to receive fuel assemblies in a vertical position.

The hy-draulically operated fuel basket on thel end of the carriage is rotated to a horizontal position for passage through' the transfer tube, and then rotated back to a vertical position in the spent fuel storage pool for vertical removal of the fuel assembly.

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i Control rods may be transferred from a spent fuel assembly to a new fuel as' em-s bly using the following procedure. Using the control rod grapple and mast 'on the' main fuel handling bridge pull the rod clear of the spent fuel while it! is standing vertically in the reactor side l of the fuel tilt mechanism. Trans fer the, spent fuel out of the reactor building and a new fuel assembly in.

With the new fuel standing vertically in the tilt mechanism, insert the control r' od.

Con' trol rods may also be transferred from one fuel assembly to another within the reactor core.

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Onc'e refueling is completed the fuel transfer canal is sealed off from the spent fuel pool by the gate valve on the transfer tube. Most of the fuel tra'nsfer canal water is then drained by, suction through a pipe located in the deep transfer station area. This water is pumped to t!.e borated water storage tank to be available for the next refueling or for emergency cooling following a1[oss-of-coolantaccident. Approximately 8 inches of water remaining in t,he fue,1 transfer canal will b gravity drained to the reactor building sump through a 2 inch drain line.

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D ng operation of the reactor, the entriage is stored in the spent fuel stor-pool, thus permitting the gate valve on the spent fuel storage pool cide ag of the,the transfer tube to remain closed and a blind flange to be installed on reactor building side of the tube, j l

l The spent fuel storage pool has space for a spent fuel shipping cask, as we(ll for required fuel storage.

as ;l assemblies are removed from storag'Following a sufficient decay period, the spent fue pin'g cask under water for removal from the site.e and loaded into the spent fuel shi'p-l A decontamination area is located in the building adjacent to the spent fuel storage pool.

In this area the outside' surfaces of the shipping casks can be decontaminated before shipment by using steam, water, or detergent solutions, and manual scrubbing to the extent required.

i 9.f$.2.3 Safety Provisions Safety provisions are designed into the fuel handling system to prevent the development of hazardous conditions in the event of component malfunctions,'

accidental. damage, or. operational and administrative failures during refueling or transfer operations.

l All-fuei. assembly storage facilities, new and spent, maintain a safe geometric spacing of 21 and 13.5 inches, respectively, between assemblics. The new and spent fuel storage racks are designed so that it is impossibic to insert fuel assemblics in other than the prescribed locations, thereby ensuring the neces-sary spacing l

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i RESTONSES TO SPECIFIC ITEMS OF INTEREST ITEM 9 35-With respect to the spent fuel storage facility provide the followin6 information:

Provide the degree of suberiticality provided by fully loaded a..

spent fuel storage-racks when stored in both borated and un-borated water.

b.

Describe the spent fuel storage racks and their arrangement in the storage Pool.

Describe the ability of the storage racks to withstand all c.

external loads and forces, the impact forces due to dropped objects, and design codes and standards complied with.

d.

Describe the minimum shielding requirements provided by the spent fuel pool and the provision incorporated into the design to assure that the minimum requirements vill be met.

Describe the instrumentation and controls provided for the spent e.

fuel pool, specifically for radiation, water level, and compo-nent failure. Provide the level at which these alarms are actuated and describe the action taken for each should they alarm.

f.

Describe.the means provided to detect and control leakage from the spent fuel pool.

I g.

Describe the methods used to assure that material compatability requirements are met for the storage facilities and the handling

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equipment.

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RESPONSE

The spent fuel storage rack is designed with a minimum 13.5" assembly spac-a.

ing to provide suberiticality in cold unborated water for clean fuel up to and including 3 5 v% enriched fuel.

For this condition, the sub-criticality margin'is in excess of 4 *. ak/k.

In Section 9.6.2 of the FSAR,'it is indicated that 2270 PPM boron'is normally in the spent fuel storage rack to prevent dilution during refueling.

For this condition suberiticality margin is in excess of 65% Ak/k.

b.

The spent fuel storage racks are structural frames consisting of beams, guide tubes and diagonal bracing acting as a unit. The racks are arranged in 17 rows consisting of 34 or-35 fuel elements for a total capacity of

= 590 spent fuci elements and 1 failed fuel element container.

9.35 Amendment No. 28 August 18, 1972

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i Tabl'e~9;9 SpentFuelCoolingSpstemPerformanceand i

Equipment Data

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Spent Fuel Heat Lead-6 I

i-i Normal ( 10 batches), titu/h 12.0x 10,

' Maximum (3-1/3-cores), Btu /h 28.5 x 10

. System Design Pressure, psig 125-System Design Temperature, F 250 Spent Fuel Coolers l

Number 2

l Type Tube and Shell Material Tube /Shell SS/CS 10 (a) l Capacity,. Btu /h/ cooler 8.75 x 6

Cooling Water Flow, lb/h/ cooler 5.0 x 105 Code Shell/ Tube AS!E VIII/III-C Spent Fuel Coolant Fumps i

' flumber 2

Type Horizontal, centrifugal

-Material

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SS I

Flow, gpm 1,000 e

Head, ft H O 100 2

Motor Size, hp

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.LO Spent Fuel Fool Volume, ft3 i

39,000-

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. Spent Fuel Coolant Filters:

Number-2 Design Flow fiate, spm.

200

. Design-Pressure, psis l

250 Design Temperature, F

-125 Material SS Code-

' AS E III-C -

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- (a) Assumes pool water to cooler at 131 F.and cooling

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l vater ~to cooler at 95 F.

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TEMPERATURE, F ARKANSAS POWER 6 LIGHT CO.

SPENT FUEL COOLING FIG. NO.

ARKANSAS NUCLEAR ONE -~ UNIT 1 10 BATCl!ES - 2 HEAT-EXCl! ANGERS 9.37-1

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SPENT FUEL COOLING FIG. NO.

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SPENT FUEL COOLING FIG. NO.

ARKANSAS NUCLEAR ONE - UNIT 1 3 1/3 CORES - 2 HEAT EXCIIANGER 9.37 - 3 I

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SPENT FUEL COOLING FIG. NO.

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