ML20206F228

Application for Amend to License DPR-36,modifying Tech Spec 1.1, Fuel Storage. Fee Paid

ML20206F228
Person / Time
Site:	Maine Yankee
Issue date:	11/08/1988
From:	Randazza J Maine Yankee
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20206F232	List: ML20206F228 ML20206F234
References
MN-88-109, NUDOCS 8811210037
Download: ML20206F228 (13)

Text

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YE.- . MaineYankee Rf ttABLE ELECTRCTY FOR WAINE S4NCE 1772 EDISCW DRIVE . AUGUSTA. MAINE 04330 . (207) 622-4868 November 8, 1988 Proposed Change #144 1 HN-88-109 l

l UNITED STATES NUCLEAR REGULATORY COMMISSION Attention: Document Control Desk ~

Hashington DC 20555 j

References:

(a) License No. DPR-36 (Docket No. 50-309) I (b) USNRC Letter to HYAPCo dated December 30, 1983, "Control of i Heavy Loads" '

(c) NUREG-0612. "Control of Heavy Loads at Nuclear Power Plants", July, 1980 (d) HYAPCo Letter to USNRC dated September 18, 1979 HHY-79-97, Proposed Change #70 (e) USNRC Letter to NYAPCo dated June 16, 1982, "Safety 1 Evaluation and Environmental Impact Appraisal Regarding Haine Yankee Spent Fuc5 Storage (f) HYAPCo letter to USNRC dated July 21, 1982, HN-82-140 (g) USNRC Letter to HYAPCo dated October 22, 1982, Resolution of Open Items - Safety Evalcation of Haine Yankee Spent 1 Fuel Storage (h) USNRC Letter to HYAPCo dated April 2, 1984, Spent Fuel Storage, Amendment #75 to Operating License No. DPR-36 (1) USNRC Letter to HYAPCo dated March 26, 1975, Cask Drop Accident l (j) SHEC Calculation 12366.02 "Cask 11 rop Analy;is - Maine Yankee", dated July 16, 1974

Subject:

Proposed Technical Specification Change Concerning Spent Fuel Shipping Casks Gentismen:

The proposed amendment would modify Technical Specification 1.1, -

Storage". Technical Specification 1.1 describes and defines thoso aspw .:  !

fuel storage which relate to the prevention of criticality in the fuel storage l facility. The proposed amendment changes specification D from "Spent fuel  !

shipping casks shall not be lifted over the spent fuel storage pool", to l "Spent fuel shipping cask, shall not be lifted over the spent fuel storage l pool until all irradiated fuel within 10 rows of the cask laydown area has cooled a minimum of 60 days. I l

postaane '

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2'.' MaineYankee

United States Nuclear Reg m , Commission Page Two Attention

Document Contrcl Desk MN-88-109 In a 1979 letter to the Nuclear regulatory Commission, Reference (d),

Maine Yankee submitted Proposed Change #70, Spent Fuel Storage Modification. A cask drop analysis was not included in the Maine Yankee Safety Evaluation since there were no plans to use a spent fuel shipping cask in the Maine Yankee spent fuel pool at that time. As a result, Technical Specification 1.1.0 was added to the Maine Yankee license to prevent the lifting of a Spent fuel Cask over the spent fuel pool (see References [e - h]). This proposed change will increase flexibility in future planning and operation. ,

Analyses have been performed to address the consequences of dropping a i spent fuel shipping cask in or near the spent fuel pool. The results of these t consequence analyses and evaluations are provided in detail in Attachment 1 -

and summarized as follows: l i

1. Any lift of a spent fuel shipping cask at Haine Yankee will be i

performed in accordance with the heavy load iiandling guidelines ,

, specified in NUREG-0612, Section 5.1.1, thus assuring an extremely low drop probability.

2. If a drop were to occur, and the shipping cask were to fall into the spent fuel pool, a maximum pool leak rate of 5 gpm has been conservatively calculated. The Chemical Volume Control System (CVCS)  !

has borated water make-up capabilities truch greater than the l postulated leak rate (i.e., 150 to 200 apm).

3. Radiological analyses have been performed which demonstrate that doses would be well within 10 CFR, Part 100 limits (i.e., less than I 25% of the Part 100 limits). The analyses determined that the 4 anticipated release from 100 fuel assemblies (i.e., the shadow area <

of the largest available shipping cask) would not exceed the l prescribed limits providing the spent fuel had decayed for 60 days.  !

. If 120 dcys were allowed, damage to every assembly in the SFP would

. not ex W 25% of the Part 100 limits. '

4. A bounding ce"$' e t ty analysis assuming 4.1 weight percent (w/o) I

U-235, pool 4 . + 'BOF and a 2-D 'nfinite array has demonstrated

.. 95 even under conditions of a collapsed i

that Kert l' i  ;

flux trap and S F :. lattice pitch, provided credit is taken for the -

1,720 ppm soluble boron. This analysis bounds consolidated fuel

assemblies.

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5. The travel path for the spent fuel shipping cask will not pass over ,

any safety-related equipment. l Hith regard to the matter of significant hazards considerations, we have i evaluated this proposed change as

• alred by 10 CFR 50.92. He concluded that ,

no significant hazards consideration exists. Our analysis is attached to this '

letter as Attachment 2. l p

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MaincYankee

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United'St'tes a Nucleas Regulatory Commission Page Three Attention: Document Control Desk HN-88-109 This proposed change has been reviewed and approved by the Plant Operation ,

and Review C( wittee. The Nuclear Safety Auc'it and Review Committee has also i raviewed this submittal. A 1epresentative of the State of Maine is being ,

1.. formed of this request by a copy of this letter He request that this proposed change be shade affective immediately upon issuance, o An application fee of $150.00 is enclosed.

Very truly yours, MAINE YANKEE ,

$ 'b b0 yw John B. Randazza l President I

R;tA/bjp l

r Attachment c: Mr. Richt.rd H. Nessman

Mr. William T. Russell Mr. Cornelius F. Holden 1 Mr. Patrick M. Stars

Mr. Clough Toppan f

. State of Maine Attorney General ,

l STATE OF MAINE f i

Then personally appeared before me, John B. Randazza, who being duly sworn [

did state that he is President of Maine Yankee Atomic Power Company, that he  !

is auly authorized to execute ard filt the feregoing request in the name and  ;

on behalf of Maine Yankee Atomic Power Company, and that the statements  ;

therein are true to the best cf his knowlecige and belief.  ;

2 & W AYL Notary Public '

sciOrIu"uSIM  !

WY COMSSC4 iXM645 QCTCMR ll,1911

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MaineYankee .

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ATTACHMENT 1 Spent Fuel Cask Drop Accident Analysis i

, i Summary of Assumptions and Results j I

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MaineYtmkee SPENT FUEL CASK DROP ACCIDENT ANALYSIS S M BY Analyses have been performed to address the consequences of dropping a spent fuel shipping carh in or near the spent fr-1 pool.

The results of these analyses are summarized below:

1. Any lift of a spent fuel shipping cask at Maine Yankee will be performe<i in accordance with the heavy load handling guidelines specified in NUREG-0612, Section 5.1.1, thus assuring an extremely low drop probability.

1. If a drop were to occur, and the shipping cask were to fall into the spent fuei pool, a maximum pool leak rate of 5 gpm has ben conservatively calculated. The Chemical Volume Coni;rol System (CW.S) has borated water make-up capabilities much greater than the postulated leak rate (i.a. 150 gpm to 200 gpm).

3. Radiological analyses have )een performed which demonstre.te that doses would be well within *10 CFR, Pai*t 100 limits (i.e., less than 25% of the Part 100 limits). The anLlyses determined that the anticipated relesse from 100 fuel assemblies (i.e., the shadow area of the largest available shipping cask) would not exceed the prescribed limits providing the spent fuel had decayed for 60 days.

If 120 dayr were allowed, damage to every assembly in the SFP would not exceed 25% of the Part 100 limits. (See Section I. for the defi nition of the cask shadow area).

4. A bounding criticality analysis assuming 4.1 w/o U-235, pool water at 680F and a 2-0 infinite array has demonstrated that Kerr is less than .95 even under conditions of a collapsad flux trap cnd optimum lattice pitch, provided credit is taken for the 1,720 ppm soluble boron. This analysis bounds consolidated f Je1 assemblies.

5. The travel path for the spent fuel shipping cask will not pass over any safaty-related equipment.

Based UPon these analyses and evaluations, the heavy load guidelines and the required drop consequences have been ,eviewed in accordance with NUREG-0512 and SRP 15.7.5, and lifting a 100-ton sper.c fuel shipping cask into the SFP cask laydown area is concluded not to represent an unreviewed safety question.

DISC %S10N NUREG-0612, Section 5.1.2, Part 4. states that the effects resulting from heavy load drops should be analyzed and shown to satisfy the prescribed evaluation criteria (Section 5.1 of Reference (c)). In addition, the general guidelines of Section 5.1.1 should also be satisfied.

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MaineYankee A discussion of the Section 5.1.1 general guidelines will be addressed first, to be followed by a sumary of the results of the Section 5.1 analyses.

General Guidelines ,

NUREG-0612, Reference (c) Section 5.1.1, states that plants should satirfy each of the following for handling heavy loads that could be brought i in proximity to irradiated fuel in the Spent Fuel Pool (SFP).

1. Safe Load Paths

2. Load Handling Procedures

3. Crane Operator Training 4, Special Lifting Devices  !

5. Lifting Devir,es (not specially designed)

6. Crane (inspection, testing, and maintenance)

7. Crane Design The yard crane (CR-3) will be used to handle spent fue*, shipping casks at Maine Yankee. This crar.J design includes travel limit switches, overspeed sensing, a second upper limit switch, and overioad sensing of the main hook.

The travel limit switches prevent yard crane travel over any spent fuel in the  :

pool. Per previous submittals, Maine Yankee has shown that a cask '

drop / tipping accident due to failure of the yard crale is of a very low probability.

Reference (b) contains the SER which documents t1e concurrence of the '

staff and its consultant (Franklin Research Center) that the guidelines in NUREG-0612 Section 5.1.1, for the handling of heavy loads have been satisfied at Maine Yankee. (Note: The use of Crane CR-3 is specifically addressed in '

Reference [b]).

Even though satisfying the above Section 5.1.1 guidelines assures an i extremely low drop probability, Reference (c) still requires consequence i aaalyses be performed for the four areas of concern discussed below.  !

Analyses were performed in the radiological release and criticality areas ,

to address these Reference (c) requirements. '

I. Radiological Releases Reference (c), Section 5.1 Part 1 states that the release of radioactive material that may result from damage to spent ful based on calculations involving accidental dropping of a postulated hesvy load should produce  !

doses that dre well within 10 CFR, Part 100, lirits of 300 rem thyroid, 25 .

rem whole body (analyses should show that doses are equal to or less than 1/4 of the Part 100 limits). -

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MaineYankee Analysis Results Since the postulated (:ask drop height could exceed 30 feet, the maximum number of spent fuel assemblies within the spent fuel cask must be included with spent fuel assemblies damaged as a result of the hypothetical cask drop (SRP 15.7.5). The current largest connercially available shipping cask is 17.5 feet high, 7.33 feet in diameter and has e capacity for sev n PHR spent fuel assemblies. As a result, if up to 93 PHR assemblies are anticipated to be damaged due to a dropped /ttpped cask (based on shadow area of cask), then 100 assemblies should be used to determine the required decay time prior to cask handling.

The Haine Yankee cask laydown area is a 10 foot square area on the west side of the spent fuel pool. The cask shadow aria was determined by asseming the cask hits the spent fuel crane rail and tips towards the east in a path perpendicular to the west wall. Assuning that 9 feet of the cask lands in the cask laydown area, about 8.5 feet impacts on fuel assemblies.

It should be note 6 that commercially available, but not yet licensed, dry casks (Castor X33) are capable of holding up to 33 assemblies; however, this type of cask is not loaded with fuel assemblies unless they have decayed a minimum of ten years. Releases from assemblies stored in dry casks need uot be included with assemblias damaged as a result of the cask drop.

Maine Yankee specific analyses were performed in accordance with the guidelines of Standard Review Plan 15.7.5 for an anticipated release from 100 fuel assemblies. In nrder to prevent exceeding 25% of the Part 100 limits,; 60 days of decay time are required for a nonfiltered release and 25 days of decay time for a filtered release.

The radiological consequences of spent fuel damage (i.e., fuel assembly gap fission product inventory releases) have been analyzed on a generic bases for a reference Flant in Reference (c). The results, parameters, ar.d assumptions used in Reference (c) have been evaluated and have been found to be bounding for the Maine Yankee Station. The results of Reference (c) could, therefore, be used to bound a potential fuel cask drop at Maine Yankee. Two cases were considered; releases to the atmosphere processed by a safety-related filter and nonfiltered releases.

Ncnfiltered releases are applicable since it is a common practice to conduct fuel cask movement with fuel building cargo doors and hatches open to the environment.

The generic analyses from Reference (c) (Section 2.1) gives required decay times of 64 days and 32 days for unflitsred and filtered release, respectively. After a decay time of 120 days, the whole body dose is limiting, and further decay time will not result in any cenefit; over 7,000 assemblies could be damaged without exceeding 25% of the Part 100 limits.

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MaineYankee II. Criticality Evaluation Reference (c) Section 5.1, Part II, states that damage to fuel and fuel storage racks based on calculattoris involving accidental dropping of a postulated heavy load should not result in a configuration of the fuel such that Keff is larger than 0.95.

Analysis Results Criticality analysis of the Maine Yankee spent fuel racks has been performed for the cask drop accident. The analysis was performed assuming fre h fuel enriched to 4.1 w/o U-235, pool water at 680F and 2-D infinite array models. Since the cas,k drop accident involves unpredictable distortions in geometry, conservative assumptions about the final geometry are made in order to bound the reactivity effects.

These assumptions include: collapsed flux trap and optimum lattice pin pitch. If credit is taken for the presenro of 1,720 ppm soluble boron in the SFP water (addressed in Referene (c) Section 5.1, Part III),

the K af of the spent fuel racks will h below .95 even under condi,tLons of collapsed flux trap and optimum lattice pin pitch. This analysia. also bounds consolidated fuel assemblies which are much less '

reactive than 14 by 14 fuel assemblies at an optimum pin pitch, as well as the older less enriched assemblics.

III. Cark Drog Reference (c). Section 5.1 Part III states thst damage to the SFP tased on calculations of damage following accidental dropping of a postulated heavy load should be limited so as not to result in water leakage that ,

could uncover the fuel (make-up water provided to overcome leakage  !

should be from a borated source of adequate concentration if the water  :

being lost is borated).

Analysis Results  ;

In 1975 the Commission reviswed Maine Yankee's analysis of a spent fuel l cask drop accident in the SFP. Per Referenc6 (i), the Commission cor..urred that no safety-related equipment was beneath the path for cask travel and that provisions to prevent a postulated spent fuel shipping cask accident were acceptable. Thera have been no changes which would adversely affect the Commission's evaluation; thus, their l conclusion tamains valid. The cask drop analysis, assumed the the cask ns dropped in an orientation wht:h results in the most severe consequences to the SFP, Rs' 'ce (j). A maximum gross weight of 100 tons for a fully loaded cast s used in the inalysis. The cask was assumed to be dropped throt'gn 4 feet of air and 38 feet of water. Drag force effects of the water medium were taken into account. The results of the analysis showed there would be minimal leakage of the SFP (approximately 2 gpm to 5 gpm).  ;

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.c 't MaineYankee 1

Estimates of leakage from the SFP are well below the borated water make-up  ;

capabilities of Chemical Vclume Control System (CVCS). The primary make-up flow paths are:

1. Concentrated boric acid solution blended with domineralized water at the blend tee or a batch makeup of concentrated boric acid with a batch makeup of domineralized water. This source uses the boric acid and primary water transfer pumps and can provide greater than 150 gpm  :

flow to the SFP via the SFP purification header.

2. Ratch makeup of refueling concentratton borated water from the i Refueling Hater Storage Tank (RHST). This source uses the refueling purification pump (P-8) and can provide greater than 200 gpm flow to the SFP via the SFP purification header.  ;

IV. Safe..S htdown Eautoment t

j Reference (c), NUREG-0612 Section 5.1, part IV, states that damage to ,

equipment in redundant or dual safe shutdown paths, based on calculations '

assuming the accidental dropping of a postulated heavy load, should be limited so as not to result in loss of required safe shutdown functions, i

Reipsni.e e .

! As stated previously (Reference [1]) in 1975, tb Commission reviewed

! Maine Yankee's analysis of a postulated spent fuel cask drop accident and agreed that no safety-related equipment was beneath the cask travel path.

C0!iCLUS10!i  ;

, The analyses and evaluations required by Reference (c) to permit a spent fuel shipping cask into the SFP cask laydown area have been performed and ,

the results demonstrate that bringing the shipping cask into the laydown  ;

area does not represent an unreviewed safety question. ,

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.- MaineYankee ATTtCHHENT 2 Deterinination of Significant Ha'.ards Censiderations I

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I MaineYankee i

Determination of Stanificant Hazards Considerations Removal of Soent Fuel Cask Handlina Restriction L

This change is requested to move a spent fuel shipping cask into the cask i laydown area of the spent fuel pool. The proposed change to tha Operating License has been evaluated to determine whether it constitutes a significant hazards consideration as required by 10 CFR 50, Section 50.91 using standaids provided in Section 50.92. This analysis is provided below:

1. The proposed amen ment will not involve a significant increase it, the probability or consecuences of an accident oreviousiv evaluated.

The large safety factors associated with the yard crane (CR-3), and  !

the fact that it meets the general guidelines of NUREG 0612 (control of heavy loads), en: ores that the probability of an accident will not be significantly increased. The results of the hypothetical cask drop analysis indicate minimal leakage to the SFP which can easily be made up by the Chemical Volume and Control System.

Fuel as*embly decay times of 60 days from shutdown to the start of cask h.'ndling result in radiological doses duc to cask drop which are well within (25% of 10CFR, Part 100) the acceptance criteria of SRP i 15.7.5. Thus, the radiological consequences of an accident will not be significantly increased.

Criticality analysis using conservative assumptions regarding spent fuel rack distortion geometry has demonstrated that Keff will always be less than the NRC's acceptance criteria, provided credit is taken for the 1,720 ppm solubie boron. Therefore, this change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

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2. The proposed amendment will not create the possibility of a new or different kind of aggigent from anv_ accident oreviously analyzed i  !

Per Reference (1), the Commission in 1975 concurred that no safety-related equipment was beneath the path for cask travel and ,

that provisions to prevent a postulated spent fuel shipping cask t accident were acceptable. There have not tseen any changes which would adversely affect the Commission's evaluation; thus their conclusion remains valid. Also, the use of specific lift procedures (which will be created upon selection of a :ask vendor) in

, conjunction with plant procedures and the safe load path ensures that ,

this change does not create the possibility of a new or different kind of accident from any previously evaluated. .

3. The proposed amendment will not involve a significant reduction in the margin of safety.  !

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NUREG-0612, Section 5.1.1, states that plants should satisfy each of the following for handling heavy loads that could be brought in l proximity to irradiated fuel in the SFP. -

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a. Safe load paths. l

b. Load handling procedures.  ;

c. Crane operator training. -

d. Special lifting devices.  !

e. Lifting devices (not specifically designed). [

f. Crane (inspection, testing and maintenance). [

g. Crane design. .

t By satisfying the above seven criteria, and through the use of procedures governing crane inspection, operation, load testing and crane operator training, we ensure that this change does not involve a significant reduction in the margin of safety.

Based on this guidance, and the reasons discussed above, wo have concluded that the proposed change does not involve a significant hazards consideration.

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MaineYankee ATTACHMENT 3 Page Change List Remove existing page 1.1-1 and replace with the enclosed page 1.1-1.

Remove existing page 1.1-2 and replace with the enclosed page 1.1-2.

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