ML17037C198

Letter Advising of Plans to Make an Addition to the Facility Under Operating License No. DPR-63 and Attaching a Safety Evaluation for Additional Spent Fuel Storage Capacity

ML17037C198
Person / Time
Site:	Nine Mile Point
Issue date:	06/10/1975
From:	Rhode G Niagara Mohawk Power Corp
To:	Lear G Office of Nuclear Reactor Regulation
References
Download: ML17037C198 (12)

Text

NRC DISTRIBUTION FOR PART 50 DOCKET MATERIAL (TEMPORARY FORM)

CONTROL NO:

FILE FROMNiagara Mohawk Power Corp. DATE OF DOC DATE REC'D LTR TWX RPT OTHER Syracuse, N. Y, Gerald K. Rhode 6-10-75 6-17-75 TO: ORIG CC OTHER George Lear 1 Signed SENT LOCAL PDR XXXX CLASS UNCLASS PROPINFO INPUT NO CYS REC'D DOCKET NO: 50 220 1

DESCR IPTION: ENCLOSURES:

Ltr. trans the following,.. ~ 1 i Safety evaluition for modification of pro-viding add'1 Spent Fuel Storage Capacity.

PLANT NAMF. Nine Mile Point Ik 1 FOR ACTION/INFORMATION VCR 6-18>>7 BUTLER (L) SCHWENCER (L) ZIEMANN (L) REGAN (E)

W/ Copies W/ Copies W/ Copies W/ Copies CLARK (L) STOLZ (L) DICKER (E) ~ LEAR (L)

W/ Copies W/ Copies W/ Copies W/l Copies PARR (L) VASSALLO (L) KNIGHTON (E) SPIES W/ Copies W/ Copies W/ Copies W/ Copies KNIEL (L) PURPLE (L) YOUNGBLOOD (E) LPM W/ Copies W/ Copies W/ Copies W/ opuses INTERNAL DISTRIBUTION TECH REVIEW DENTON LIC ASST A/T IND P LE

~

R SCHROEDER GR IMES R. DIGGS (L) B RA ITMAN OGC, ROOM P-506A MACCARY GAMMILL H. GEARIN (L) SALTZMAN GOSS I CK/STAF F KNIGHT KASTNER E. GOULBOURNE H-) ME LTZ CASE PAWLICKI BALLARD P. KREUTZER (E)

G I AMBUSSO SHAO SPANG LER J. LEE (L) PLANS BOYD STELLO M. MAIGRET (L) ~MCDONALD MOORE (L) HOUSTON ENVI RO S. REED (E) CHAPMAN DEYOUNG (L) NOVAK MULLER M. SERVICE (L) DUBE (Ltr)

SKOVHOLT (L) ROSS DICKER S. SHEPPARD (L) E. COUPE GOLLER (L) (Ltr) IPPOLITO KNIGHTON M. SLATER (E) PETERSON P. COLLINS TEDESCO YOUNGBLOOD H. SMITH (L) HARTFIELD (2)

DENISE LONG REGAN S. TEETS (L) KLECKER REG OPR LAINAS PROJECT LDR G. WILLIAMS(E) EISENHUT FILE 5 REGION (2) BENAROYA V. WILSON (L) Wl GG I NTON MIPC VOLLMER HAR LESS R. INGRAM (L) 1 M. DUNCAN

~ 1 1

LOCAL PDR TIC (ABERNATI.IY)

NSIC (BUCHANAN)

) (2) (10) 1 EXTERNAL DISTR I BUTION NATIONALLABS W. PENNINGTON, Rrn E-201 GT 1

1 P DR-SAN/LA/NY BROOKHAVEN NAT LAB G. U LR I KSON 0 R N L 1 ASLB 1 CONSULTANTS 1 1 Newton Anderson NEWMARK/B LUME/AGBABI AN ACRS HOLDING/SENT

r-C

~ ~ 4

~ ~ ~ ~ 0 4 ~

h

gjle Cf~")

NIAGARA MOHAWK POWER CORPORATION q 8 NIAGARA ' MOHAWK

'y p-300 ERIE BOULEVARD WEST / Qk g(/Su SYRACUSE. N. Y. 1320R Cloy June 10, 1975 QV

'~C

- Mr. George Lear, Chief r<,

";. Operating Reactors Branch 83 4Pg u Sp Division of Reactor Licensing d "

u U. S. Nuclear Regulatory Commission O/p f Washington, D. C. 20555 Re: Nine Mile Point Unit 1 Docket No. 50-220

Dear Mr. Lear:

-Pursuant to Section 50.59 of the Code of Federal Regulations, Title 10, Niagara Mohawk plans to make an addition to its facility under Operating License No. DPR-63. Briefly, this addition is for the purpose of providing additional spent fuel storage capacity.

Attached for your information is a safety evaluation for the modification including a description of the proposed change. This evalu-ation shows that the probability of occurrence of an accident would not be increased, that no new type of accident would be introduced, and that safety margins for spent fuel storage would not be reduced.

The proposed modification has been reviewed and approved by the Site Operations Review Committee and the Safety Review and Audit Board.

Very truly yours, NIAGARA MOHAWK POWER CORPORATION Gerald K. Rhode Vice President-Engineering Attachment

\

it I

\

Nine Nile Point Unit 1 SAFETY EYALUATION FOR ADDITIONAL SPENT FUEL STORAGE CAPACITY A.

SUMMARY

O~i1 0 The spent fuel storage pool is a reinforced concrete structure lined with stainless steel plate. The poo1 is 33'2" wide, 37 ' 1/2" long, and 38'10" in depth. It was designed specifically to maintain the mean temperature of the pool below 125 F. In so doing, it was originally considered that the pool should accommodate 150 percent of full core capacity and the associated 20 x 10 6 BTU/hr heat load that would result. The spacing of the fuel bundles is maintained such that the Effective Multiplication Factor (Keff) is always less than 0.90.

2. Reason for Chan e The addition of twelve spent fuel storage racks is proposed to rovidee sufficient provi u capability to store a full core discharge following the Fall, 1975 refueling. This additional capability is required d ue to the recent removal of six spent fuel storage rack locations for installation of the Cask Drop Protection System, and also because of the unavailability of off-site reprocessing facilities.

3. Effect Of Chan e Analysis of the proposed addition shows the following:

a. The probability of occurrence of an accident or malfunction is no greater.

b. No new type of accident will occur.

c. There will be no reduction to the margin of safety of the plant.

d. No change to the Technical Specifications is required.

1 I l I

~ ~

E.

B. DISCUSSION

~Pd Ch The original spent fuel pool design provided for 64 storage rack positions for the spent fuel, control rod blades, and channels.

Six of these positions were recently removed because of the installa-tion of a Cask Drop Protection System. At present there are 40 spent fuel storage racks with the capacity for 800 bundles (300 occupied), 13 control rod racks with the capacity for 130 blades ,

(4 occupied), and one channel rack with the capacity for 20 channels (none occupied). Four storage racks positions are present'ly un-occupied in the pool.

Twelve additional spent fuel storage racks, with the capacity for 240 bund1es are proposed. They are identified as "New" in the attached illustration, and will be identical in design to the original racks. Also, spacing of the racks will be identical to the original design.

The addition of the spent fuel storage racks will require that eight control rod racks be moved from their swing bolt positions

~

to an ais'Ie area of the poo't floor, per the attached illustration.

There, they will be bolted to a support base, and braced laterally for seismic considerations.

2. ~Ana1 sis

a. Seismic Considerations on Pool Loadin The spent fuel pool was originally designed assuming all available positions (64) were occupied. The additional racks will result in a net increase of two positions and will have no significant effect on the pool loading. The control rod racks, relocated to the aisle of the pool, as proposed, will not overstress the supports of the spent fuel storage racks when subjected to the original horizontal design earthquake acceleration of 0.25 g.

b. ~Shia1din Presently the reactor floor area is a controlled "Radiation Area", where entry is controlled for radiation purposes. As defined in the Station's radiation protection procedures, a "Radiation Area" is one where the radiation level is from 5 mrem/hr to 100 mrem/hr . P'resently the dose level around

. the spent fuel pool area is about 5 mrem/hr, largely a result of the radioactivity in the spent fuel pool water. The increase in the number of spent fuel pool bundles may increase this level slightly but will not cause the control of this area to be changed.

\

C V r

--3--

c. Effective multi lication Factor (Keff)

The original calculations which limit keff to less than 0.9 are based on the spacing of the spent fuel storage racks and not the number. The racks being added are designed and will be placed in the pool such that spacing is identical to that of the original racks. Thet efore, keff will remain unchanged.

d. S ent Fuel Pool Coolin The spent fuel pool filtering and cooling system was designed to remove decay heat and impurities from the pool water so as to maintain the mean water temperature at or below 125 F and to assure visual clarity under all anticipated conditions. The proposed addition would provide storage for approximately 200 percent of full core capacity, resulting in a heat load of 27.3 x 106 BTU's/hr. Based on a fuel inventory consisting of'0 percent core storage with one year or greater decay, 40 percent

.with two months decay and 100 percent with 12.-days decay, the spent fuel pool filtering and cooling system will still maintain the mean water temperature at or, below 125 F and assure visual clarity of the water.

e. U-235 and B -Product Inventor Our operating license allows for the possession of 3800 kg of U-235 and associated by-products. Calculations show that even after the Spring, 1977 refueling, we will still have less than 3000 kg of U-235 on-site.

v '.<

e e ~

~

f

~ / I. 0~ (

/

I I

I~4 I

I I 4 A rC 'V>>i &V:%

I I

I I

~ /r r

N. 07 PQb':QGMS .

P VXV"-.~'"

'O I 1 C~%'w AR>> 4 I I I I z ~

4"1 PA ~ AG We% tOLO I

I cA I

l I

j [ I, O

C.OW-1" ~C V.O~ m,e~ ... HO ...

I I I I I goal

... Zo,

~

I I . I I tA c.'rQNM"='~ 3.ke<

I LII 0 iII

)

CJ L r, C. ~

/

w)

I Ir

.~ ~ r/ V

'/ <<'bMC>>

'I I

• I

/

,~ / // 'AhB A. I I/(

'I SZ";VV C.s"qadi

' I.'.

%WCTU ".~0=  ! wj -oQ A'j (rv,. z.~v.=~ z f

~

L; (a'cv.>

f!

ji

/ 0

'? I l

'II r I I

in li l~cA.'i'I

~1, QJ XIV,C;X~X NOV,>iVW ";Ox>>a CCa<

~r GR l' P QZ 5't 'AV %X '4M< NU:= PO&'T 5<:.a r-o ~ r-oo4 I POPO V"'0 gQ'Dh >(ON P4 o~ BP='N7 "-.QK PQG~

~ /

d

~ ~ 0 4

1