ML20059L393

Application for Amends to Licenses DPR-53 & DPR-69,allowing Containment Personnel Airlock to Be Open During Core Alterations & Movement of Irradiated Fuel in Containment Provided Certain Conditions Met

ML20059L393
Person / Time
Site:	Calvert Cliffs
Issue date:	11/05/1993
From:	Denton R BALTIMORE GAS & ELECTRIC CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20059L397	List: ML20059L393 ML20059L401
References
NUDOCS 9311170051
Download: ML20059L393 (10)

Text

i e l BALTIMORE GAS AND ELECTRIC l

1650 CALVERT CLIFFS PARKWAY . LUSBY, MARYLAND 20657-4702 ROBERT E DENTON Vict PRE $sDENT NUCLE AR ENERoy (4Cl P60 4455 November 5,1993 r

U. S. Nuclear Regulatorj Commission Washington, DC 20555 ATTENTION: Document Control Desk

SUBJECT:

Calvert Cliffs Nuclear Power Plant Unit Nos.1 & 2; Docket Nos. 50-317 & 50-318 License Amendment Request; Personnel Airlock Open During Core Alterations

REFERENCES:

(c) Letter from G. C. Creel (BG&E) to Document Control Desk (NRC),

dated November 7,1990, " Request for Amendment to Operating Licenses" l

(b) Ixtter from D. G. Mcdonald (NRC) to G. C. Creel (BG&E), dated June 7,1991, " Issuance of Amendment for Calvert Cliffs Nuclear l Power Plant Unit Nos. I and 2" ,

(c) Ixtter from A. E. Lundvall, Jr. (BG&E) to D. G. Eisenhut (NRC), i dated March 1,1982," Control of Heavy 1. cads" Pursuant to 10 CFR 50.90, the Baltimore Gas and Electric Company (BG&E) hereby requests an Amendment to Operating License Nos. DPR-53 and DPR-69 by the incorporation of the changes described below into the Technical Specifications for Calvert Cliffs Unit Nos. I and 2.

l DESCRIPTION Technical Specification 3.9.4, " Containment Penetrations," requires that the containment penetrations be closed during core alterations and movement of irradiated fuel in the containment.

The proposed change would allow the containment personnel airlock (PAL) to be open during these conditions provided that certain conditions are met.

This change is applicable to most Pressurized Water Reactors (PWRs) as discussed in the section,

" Generic Applicability."

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Document Control Desk November 5,1993 Page 2 >

HACKGROUND Technical Specification 3.9.4, " Containment Closure," requires that a minimum of one PAL door, as well as other containment penetrations, be closed during core alterations and movement ofirradiated fuel within the containment. This requirement is reflected in the Calvert Cliffs Updated Final Safety Analysis Report (UFSAR), Section 14.18, " Fuel Handling Incident." The accident analysis assumes that in the event of a fuel handling accident in the containment, no radioactive release occurs because the containment is closed. The fuel handling accident analysis also assumes that the minimum water level above the fuel (23 ft) and the minimum decay time prior to fuel movement (72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />) are those required by Technical Specifications.

! I During a refueling outage, other work in the containment does not stop during fuel movement and core alterations. This requires that personnel operate the PAL doors to enter and exit the containment. During the 1993 Unit 2 refueling outage, from the period May 7 - May 17 when the PAL doors were closed for fuel movement, it is conservatively estimated that there were 10,000 entries made into containment. Assuming an average of 4 persons per PAL cycle, the doors (which weigh over 2000 pounds each) were cycled over 250 times a day. We believe that crowding of pers mnel in the PAL during shift changes may cause an increase in personnel contamination. Such heavy use of the PAL was not anticipated during its design. The original purchase specification for the PAL states that its purpose is to allow entries during power operation and to withstand a

! pressure of 50 pounds per square inch following an accident. During shutdown conditions, the PAL l purchase spccification states that the equipment hatch would be used for both personnel and equipment entry. As a result of this unexpectedly heavy use, failures of the door hinge pin, tCoor seals, the packing of the equalizing valve, and other components have occurred. We have used trained, dedicated door operators in an effort to minimize damage to the door, but problems have persisted. These failures of the PAL doors raise the concern that the PAL might not be able to be scaled in the event of an accident. In addition, two critical path days were lost in the 1992 Unit I refueling outage due to door failures.

From a practical standpoint, Specification 3.9.4 will net prevent all radioactive releases from the containment following a fuel handling accident. There are a large number of people in the containment during a refueling outage, even during fuel movement and core alterations. Should a fuel handling accident occur, it would take a number of cycles of the airlock to evacuate personnel from the containment. With each PAL cycle, more containment air would be released. While waiting for their turn to exit, the workers would be exposed to the released activity. Alternatively, the Shift Supervisor could invoke 10 CFR 50.54(x), order both doors opened while the personnel in the containment are evacuated, and then close the doors. In either case, there is a release of activity into the atmosphere. Under the proposed change, the containment could be evacuated without invoking 10 CFR 50.54(x) and then scaled. This would reduce dose to workers in the event of an accident while maintaining acceptable doses to the public.

Protection against radioactive release due to loss of shutdown cooling is provided by the shutdown cooling technical specification which requires that all penetrations between the containment and the atmosphere be closed within four hours upon the loss of shutdown cooling. The electrical specifications require that the containment be closed within eight hours of the loss of the required electrical supplies.

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{ l l Document Control Desk l November 5,1993 l Page 3 We have performed a new fuel handling accident analysis which assumes that the containment PAL is open at the time of the accident. The details of that analysis are described below and in '

Attachment (4). The analysis shows that it is not necessary to have containment closure in order to show acceptable site boundary doses following a fuel handling accident.

The proposed amendment consists of two related changes. 'Ihe first change modifies the Calvert Cliffs containment penetration technical specification to resemble the containment penetration technical specification in NUREG-1432, Standard Technical Specifications for Combustion Engineering Plants (STS). The second change allows the containment personnel airlock to be open during fuel movement and core alterations.

CIIANGE 1 - Mons:T Tire CALVERT Cf.lFFS CONTAINMENT PENETRATION TECIINICAL SPECIFICATIONS To HEsEMitLE TIIE STANnARn TECIINICAL SPECIFICATIONS Attachments (1) and (2) contain marked-up technical specification pages for Units 1 and 2, respectively. This change is plant-specific to Calvert Cliffs.

l l This proposed change revises Specification 3.9.4, " Containment Penetrations, Shutdown" to make it consistent with the same Specification in the SE. It deletes " positive reactivity changes" and

" movement of heavy loads over irradiated fuel within the containment building" from the  ;

" Applicability," " Actions," and " Surveillance" sections. In addition, the " Applicability" and

• Surveillance sections are revised by removing references to " degraded electrical conditions" and substituting equivalent actions in lieu of references to Specification 3.9.4 in Specifications 3.8.1.2, 3.8.2.2, and 3.8.2.4.

SAIYlY ANAIXSIS Calvert Cliffs Technical Specification 3.9.4 is not the same as the corresponding technical specification (3.9.3) in the SU. The differences are in the Applicability, Actions, and Surveillance sections. Revisions to the existing specification to make it resemble the standard will simplify the generic application of the other proposed change in this request.

Calvert Cliffs Specification 3.9.4 is applicable "During Core Alterations, positive reactivity changes, movement of irradiated fuel within the containment, movement of heavy loads over irradiated fuel within the containment building, and Electrical Power Distribution System degradation as required by Specifications 3.8.1.2, 3.8.2.2 and 3.8.2.4." This applicability is also reflected in Action Statement 3.9.4.a and Surveillance 4.9.4. The STS 3.9.3 is applicable only,"During Core Alterations and during movement ofirradiated fuel assemblies within containment."

The additional conditions for applicability in Calvert Cliffs Technical Specification 3.9.4 were requested as part of a license amendment which altered the actions to be taken during periods of electrical system degradation. Reference (a) is the license amendment request and Reference (b) is the approved amendment. According to Reference (a), the first two additional conditions (positive reactivity changes and movement of heavy loads over irradiated fuel in the containment) were added because they were contained in a draft of the STS that was current at the time of the amendment (version dated July 24,1990). No safety reason was given for the additional restrictions and the Nuclear Regulatory Commission's Safety Evaluation Report does not appear to credit their use. As stated above, these additional conditions were not incorporated into the final version of the SE and are removed by this change in order to maintain consistency with the Standard. Furthermore, these

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Document Control Desk November 5,1993  :

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two applicability conditions are unnecessary. Protection from positive reactivity changes large enough to cause criticality is provided by Specification 3.9.1, " Refueling Boron Concentration." .

Heavy load movement over irradiated fuel was evaluated in BG&E's response to Control of Heavy  ;

Loads (NUREG-0612) (Reference c) and appropriate administrative controls were implemented to prevent damage of irradiated fuel by such movement. The applicability condition in Specification 3.9.4 did not exist at the time of our response and was not added in response to NUREG-0612.

The electrical degradation restriction in Calvert Cliffs Specification 3.9.4 is a reference to requirements in Specifications 3.8.1.2,3.8.2.2, and 3.8.2.4. Standard Technical Specification 3.93,

" Containment Penetrations" is not applicable during periods of electrical degradation. The proposed change will preserve the existing requirements in the electrical specifications by eliminating the references to Specification 3.9.4 and substituting equivalent actions in the electrical specifications.

The references to the electrical specifications in Specification 3.9.4 are not necessary to maintain equivalent actions and have been removed to make the Specification consistent with the STS.

DETERMINATION OF SIGNIFICANT IIAZARDS The proposed change has been evaluated against the standards in 10 CFR 50.92 and has been determined to not involve a significant hazards consideration, in that operation of the facility in accordance with the proposed amendment:

1. Would not involve a significant increase in the probability or consequences of an accident previously evaluated.

The only previously evaluated accident affected by containment penetration status during shutdown is a fuel handling accident in the containment. Containment penetration closure is required during periods when the plant is shutdown and the risk of a fuel handling accident is higher in order to minimize the release of radioactive material due to such an accident. The proposed change modifies the conditions of Specification 3.9.4 regarding when containment penetration closure is required in order to make the Calvert Cliffs technical specification resemble the Standard Technical Specifications, Combustion Engineering Plants (NUREG-1432). This involves eliminating applicability of the specification during periods of l positive reactivity addition, movement of heavy loads over irradiated fuel in the containment, and periods of electrical degradation. Containment penetrations are not an initiator to any i accident so the status of containment penetrations has no affect on the probability of an accident previously evaluated.

Two applicability conditions of Specification 3.9.4, " positive reactivity additions" and

" movement of heavy loads of irradiated fuel in the containment," are not needed because equivalent protection is provided by Specifications 3.9.1, " Refueling Boron Concentration,"

and by previous analysis of control of heavy loads. The actions to be taken during electrical degradation have been relocated from Specification 3.9.4 to the electrical specifications (Technical Specifications 3.8.1.2, 3.8.2.2, and 3.8.2.4). Therefore, the proposed changes provide a level of protection against radioactive release from the containment during shutdown conditions equivalent to the existing specifications.

Therefore, the proposed change does not involve a significant increase in the probability or  !

l l consequences of an accident previously evaluated.

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i ln Document Control Desk l November 5,1993 l Page 5 l

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2. Would not c eate the possibility of a new or different type of accident from any accident previously evaluated.

The proposed changes to Specification 3.9.4 will provide a level of protection against radioactive release from the containment equivalent to the current specifications. It does not represent a significant change in the configuration or operation of the plant which could create the possibility of a new type of accident. Positive reactivity changes which could potentially violate the required shutdown margin were evaluated in determining the technical specification limit for refueling boron concentration (Specification 3.9.1), and movement of heavy loads over irradiated fuel has been previously evaluated in our response to NUREG&l2,

• Control of Heavy Loads." Actions to be taken during periods of electrical degradation have been relocated within the technical specifications but remain unchanged.

Therefore, the proposed change does not create the possibility of a new or different type of accident from any accident previously evaluated.

3. Would not involve a sigmficant reduction in a margin ofsafety.

The proposed changes will climinate some conditions when containment penetration closure is required. This could allow the release of radioactivity from containment. However, for each chminated condition there is an existing equivalent or more restrictive requirement which would prevent events which would result in a radioactive release. Therefore, there will be no increase in offsite dose and the margin of safety is maintained.

Therefore, the proposed change does not involve a significant reduction in a margin of safety.

CllANGE 2 - mod 11T Tite CAIXERT C UFFS CONTAINMENT PENFTRATION TECIINICAL SPEcirICATloNS To allow Tite CONTAINMENT PERSONNEL AIRLOCK To HE OPEN DURING Ft'EL MOVEMENT AND CORE ALTERATIONS t

Attachments (1) and (2) contain marked-up technical specification pages for Units 1 and 2, respectively.

This proposed change revises Specification 3.9.4, " Containment Penetrations, Shutdown," to allow the containment personnel airlock to be open during fuel movement and core alterations provided that one PAL door is operable, the plant is in MODE 6 with 23 feet of water above the fuel, and a l designated individual is continuously available to close the airlock door. This individual must be stationed at the Auxiliary Building side of the outer airlock door.

l Consistent with STS, features required for PAL operability are given in the Bases. The Bases state l that in order for a PAL door to be operable, it must be capable of being closed and the airlock l doorway must not be blocked.

In addition, Specification 3.9.3, " Decay Time," is modified to lengthen the minimum time between l subcriticality and fuel movement from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br />.

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Document Control Desk November 5,1993 Page 6 GENERIC APPLICAHILITY The proposed change is generically applicable to those PWRs which are required to have the PAL closed during fuel movement and core alterations. Some PWRs are not required to close the PAL during fuel movement and core alterations. Justification for such specifications include a PAL which opens into a filtered area of the Auxiliary Building, such as the Spent Fuel Pool or continuous use of a filtered containment exhaust. However, the majority of PWRs have specifications similar to Calvert Cliffs and can make use of this change. Specification,3.9.3, " Containment Penetrations," is the same in all of the PWR Standard Technical Specifications (NUREG-1430,1431 and 1432). In response to an industry survey,13 plants stated that they would be interested in adopting this change.

This proposed change was presented to the Technical Specification Improvement Program lead plants. All three PWR owners groups endorsed the praposed change. The owners groups will move to incorporate the proposed change into the Standard Technical Specifications if this change is approved.

SAFETY ANALYSIS The purpose of the current requirement to have one containment PAL door closed during core alterations and fuel movement is to prevent the escape of radioactive material in the event of a fuel handling accident. This assumption is reflected in the analysis for this accident as documented in the Calvert Cliffs UFSAR, Section 14.18, " Fuel Handling Incident." A new fuel handling accident analysis was performed which does not assume that the containment PAL is closed at the time of the accident. The new analysis does assume that the fuel has decayed following shutdown for 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> prior to the accident and that there is at least 23 feet of water above the fuel as required by Calvert Cliffs Technical Specification 3.9.10.

Experience has shown that the heavy use of the containment PAL during refueling has led to failures of the door, raising the concern that the door may be unavailable in the event of an accident. In addition, the current analysis assumption that there is no release is flawed because some release would occur as the personnel in containment exit through the PAL The personnel would also be exposed to the radioactive material in containment while waiting to exit.

The offsite dose results of this new analysis are well within the limits of 10 CFR Part 100, as described in Standard Review Plan 15.7.4, Revision 1. The analysis results in a maximum offsite dose of 14.06 Rem to the thyroid and 0.457 Rem to the., whole body. The Standard Review Plan guidelines are 259c of the 10 CFR Part 100 limits, e.g.,75 Rem to the thyroid and 6 Rem to the whole body.

Actual offsite doses in the event of a fuel handling accident will be less because the PAL door will be closed following evacuation of the containment. Our analysis assumes that the release continues for two hours. The current Fuel Handling Incident analysis (UFSAR Section 14.8) for a fuel handing accident in ccmtairiment assumes no offsite dose results because the containment is closed. The current analysis for a fuel handling accident in the Spent Fuel Pool (Auxiliary Building) results in offsite doses of 2.76 Rem to the thyroid and 0.30 Rem to the whole body. This dose is lower than the new analysis site boundary dose because the Spent Fuel Pool area effluent is filtered and because different input assumptions were used.

a Document Control Desk November 5,1993 Page 7 The proposed change to Specification 3.9.3, " Decay Time," would lengthen the minimum time between subcriticality and fuel movement from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br />. This time is used as in input assumption to the fuel handling accident and represents the decay time for radioactive materialin the fuel prior to a postulated fuel handling accident. Increasing the decay time from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br /> reduced the doses at the site boundary from a fuel handling accident with the PAL open by 1 1.81 Rem to the thyroid and 0.062 Rem to the whole body. This change partially compensates for the higher site boundary doses resulting from assuming that the containment PAL doors are open.

ne proposed change contains restrictions on allowing both PAL doors to be open to ensure that at least one door will be available to perform its safety function. He restriction to Mode 6 with 23 feet i of water above the fuel provides sufficient time to respond to a loss of shutdown cooling. Requiring .

a door to be operable ensures that a door is available to be closed in the event of an accident.

Prohibiting the blocking of the doorway by cables, hoses, etc., also ensures that the door can be closed. Requiring that a designated individual is available outside of the affected area, e.g., the containment, to close the door following evacuation of the containment will minimize the release of radioactive material.

This change represents the potential for an increased dose at the site boundary due to a fuel handling accident. However, the dose remains well below the acceptable limits and its overall significance will '

be offset by the increased decay time, the decreased potential radiation dose to workers in the event  :

of a fuel handling accident, and the increased availability of the PAL door in the event of an accident.

DETERMINATION OF SIGNIFICANT IIAZARDS The proposed change has been evaluated against the standards in 10 CFR 50.92 and has been determined to not involve a significant hazards consideration, in that operation of the facility in accordance with the proposed amendment:

1. Would not imohe a significant increase in the probability or consequences of an accident previously evaluated.

The proposed change to Spec;fication 3.9.4 would allow the containment personnel airlock (PAL) to be open during fuel movement and core alterations. The PAL is closed during fuel movement and core alterations to prevent the escape of radioactive materialin the event of a fuel handling accident. The PAL is not an initiator to any accident. Whether the PAL doors I are open or closed during fuel movement and core alterations has no affect on the probability

! of any accident presiously evaluated.

l Allowing the PAL doors to be open during fuel movement and core alterations does increase the consequences of a fuel handling incident in the containment from no offsite dose to 14.06 Rem to the thyroid and 0.457 Rem to the whr;e body. However, the calculated offsite doses are less than 59c" of the limits of 10 CFR Part 100 and, therefore, do not represent a significant increase in offsite dose. In addition, the calculated doses are larger than the expected doses because the calculation does not incorporate the closing of the PAL door after the containment is evacuated. The proposed change will significantly reduce the dose to workers in the containment in the event of a fuel handling accident by speeding the

' containment evacuation process. The proposed change will also significantly decrease the wear on the PAL doors and, consequently, increase the availability of the PAL doors in the

event of an accident.

Document Control Desk November 5,1993 Page 8 The proposed change increases the minimum decay time from shutdown to the movement of irradiated fuel in containment. Minimum decay time is not a precursor to any accident.

Lengthening the minimum decay time decreases the consequences of a fuel handling accident by reducing the radioactive inventory of the irradiated fuel.

Therefore, the proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

2. Would not create the possibility of a new or different nye of accident from any accident previously evaluated.

The proposed change affects a previously evaluated accident, e.g., a fuel handling incident. It does not represent a significant change in the configuration or operation of the plant and, therefore, does not create the possibility of a new or different type of accident from any accident previously evaluated.

3. Would not involve a significant reduction in a margin ofsafety.

The margin of safety as defined by 10 CFR Part 100 has not been significantly reduced.

There is an increase in calculated offsite dose resulting from a fuel handling accident but the increase is a small fraction of the limits given in 10 CFR Part 100. The proposed change also increases the minimum decay time from shutdown to the movement of irradiated fuel in containment. This change reduces the offsite dose in the event of a fuel handling accident which partially compensates for the higher offsite doses under this proposed change.

Therefore, the proposed change does not involve a significant reduction in a margin of safety.

Moreover, the Commission has provided guidarsce concerning the application of standards in 10 CFR 50.92 by providing certain examples (March 6,1986 51FR7751) of amendments that are considered not likely to involve a significant hazards consideration. This proposed change is very similar to example (vi) in the Federal Register Notice, in that this change results in an increase in the consequences of a previously analyzed accident, but the results of this change are clearly within all acceptance criteria. The criteria for fuel handling accident results are found in Standard Review Plan 15.7.4, Revision 1.Section II.1, " Acceptance Criteria," provides exposure guidelines for offsite dose calculations. The guidelines given are 75 Rem to the thyroid and 6 Rem to the whole body.

The results we have calculated,14.08 Rem to the thyroid and 0.457 Rem to the whole body, clearly fall within those acceptance criteria. Therefore, based on the information contained in this submittal, we believe that this change does not result in a significant hazard.

ENVIRONMENTAL ASSESSMENT The proposed amendment would change requirements with respect to the installation or use of a facility component located within the restricted area, as defined in 10 CFR Part 20, or changes to an inspection or surveillance requirement. We have determined that the proposed amendment involves no significant hazards consideration, and that operation with the proposed amendment would result in no significant change in the types or significant increases in the amounts of any effluents that may be released offsite, and in no significant increase in individual or cumulative occupational radiation exposure. Therefore, the proposed amendment is eligible for categorical exclusion as set forth in

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November 5,1993 i Page 9 10 CFR Part 51.22(c)(9). Pursuant to 10 CFR 51.22(b), no emironmental impact statement or  !

emironmental assessment is needed in connectbn with the approval of the proposed amendment.

SCllEDULE This change is requested to be approved and issued by April 1.1994. However, issuance of this l amendment is not currently identified as having an impact on outage completion or continued plant  ;

operation. j SAFL'IY COMMITTEE REVIEW These proposed changes to the Technical Specifications and our determination of significant hazards have been reviewed by our Plant Opera,.ons and Safety Review Committee and Offsite Safety Review Committee. They have concluded that implementation of these changes will not result in an  ;

undue risk to the health and safety of the public.

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i Document Control Desk l November 5,1993 Page 10 Should you have any questions regarding this matter, we will be pleased to discuss them with you.

Very truly yours,

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l STATE OF MARYLAND :

TO WIT :

COUNTY OF CALVERT  : '

I hereby certify that on the day of Movemb ,19 D, before me the subscriber, a Notary Public of the State of Maryland in and for C alueet C M Eld ,

personally appeared Robert E. Denton, being duly sworn, and states that he is Vice Pr6sident of the Baltimore Gas and Electric Company, a corporation of the State of Maryland; that he provides the foregoing response for the purposes therein set forth; that the statements made are true and correct to the best of his knowledge, information, and belief; and that he was authorized to provide the response on behalf of said Corporation.

WITNESS my Hand and Notarial Scal: Y [

Notary Public My Commission Expires: M4</ . /k J5 ate RED /BDM!dlm Attachments (1) Unit 1 Technical Specification Revised Pages (2) Unit 2 Tcchnical Specification Revised Pages (3) NUREG-1432, " Standard Technical Specifications for Combustion ,

Engineering Plants," Revised Pages '

(4) Summary of the Analysis of a FuelIlandling Accident cc: D. A. Brune, Esquire J. E. Silberg, Esquire R. A. Capra, NRC D. G. Mcdonald, Jr., NRC T. T. Martin, NRC P. R. Wilson, NRC R. I. McIzan, DNR J. H. Walter, PSC