ML20114B540

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Rev 0 to Safety Evaluation. W/One Oversize Encl
ML20114B540
Person / Time
Site: Shoreham File:Long Island Lighting Company icon.png
Issue date: 08/26/1992
From:
LONG ISLAND POWER AUTHORITY
To:
Shared Package
ML20114B539 List:
References
92-564, 92-564-R, 92-564-R00, NUDOCS 9208280344
Download: ML20114B540 (24)
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{{#Wiki_filter:u., M'E64 MV 0 14ad SA:?:ETY :EVALUAT::0N 5" - - r o Aut.bonty i 511EET OT SCOPE OF SAFETY NALUATION This safety evaluation (SE) addresses the design and operation of ihe Dry Cutting Station (DCS). The DCS is an enclosure that contains the cutting equipment to segment the Reactor Pressure Vessel trPV) shcIl sections and designated RPV intemals. It provides a controlled environment f or cutting opentions and controls the spread of contaminatioi> This SE is an evaluation of the modified DCS to be implemented and includes a review of the differences bei voen that design and the onginal one as - descobed ir the Decommissioning Plan (DP) and the LIPA responses to NRC questions (DP supplement). RFFERENCES 1. Code of Federal Regulations,10CFR50.59 t i 2. Engineering Change Report. ECR H 1502B 3. Defueled Safety Analysis Report (DSAR) Rev. 3, Chapters 2.3,4.6.7,9,11.16 and 17. 4. Defueled Technical specification (POL) (Appendix " A" to NPF 082. Docket No. 50 322. June 14 1991). References are continued on page 3. DISCUSSION See Pago 3 CONCLUSION l The modified DCS design neither results in an unreviewed safety question nor does it have any adverse impact on any safety related structures, systems or components in the defueled plant. The operations and maintenance of the safety related items and the Defueled Technical Specifications are not affected. The implementation of the modified DCS design will not result in an increase in potential radiological impact to the off site general public. An update to the DP must be made to reflect the changes in 'he implementation activities, No change to the Supplement to Environmental Report (Decommissioning) will be necessary. PREPAREP." ATE REYlEWER 1 DATE ,kN,$w $ b4 % Mn 6dL.K d' 2/k& / APPROVALS 1J SECT 10. MTE OPS DIY1510N MANAGER (Reg. Safety Rel.I ' DATE RESJ ( A 4 A lt 8h6/7A NR _ x II Q10N 3p'N1.. Cih DFA, MGR. fl DATE }L h4 n'}0r n 4v1(9AA0841 l$ V" V \\ DATE DIV. alANAGER (l.AST) /Ib ON 92002Bo 344 920827 /y y Gr T. Car gg DR ADOCA 0S00 2 c.

.-.._._.~ -- - - - - - - - - -. - - - -.- - - -.- 5i r,2. ~~~f.L. & V. O ancut z :: t1 SATETY IVALVA;;;;i CHttrJ.: 7 IROPfriAF. M: LIAR-POWIR ITATION ~ '. ) CHICCIST APPLICA&Lt 70. O E GI C, M Ct: Mop (FIED 0C5 t 2) SArtTT EVEUATICH - PART A The itam to whith this evaluatten is applicacle represents: a change to the station cr pr:cecures as cascrited in the D3AR/USARe y or a test cr experLment not -wescraced in the DSAR/USAR. fes When the answer to the above is *Yes*, attach s-detailed deuctlption of the item being evaluated and the affectea section(s) of the + DSAR/USAR with the applicaolu enanges indicated. .3) SATETY EYLLUATICH - PART B 'Will this item require a change t: the statien Defueled Tecnnical Yes _ No M. Specifications When the answer to the above as *Yes, identify the Spectfication(s) a -affe Las ans/or attach tr.e appi :acle pagets) itth sne enangets indicated. -{4) SAMTY EVALUATICH ~ PART C The item to which this evaluation is applicaele-is a decemmissioning activity and represent s a enange or devtatt:n irem the, Decommissioning Yes'g No Plan l(DP).. gg y, f, When the' answer to the above is "yes", attaca e detailed description -of the itec. being evaluated and identify the affected section(s) of the DP with the applicaele changes or deviations indicated. (5) SATETY EV E UATICN - PART D As a result of the item to which this evaluation is applicables (A) Will the pretability of an acetdent previously evaluated in the.DP/DSAR/USAR be increased? Y y (3) Will the consequences of an aceteent previously evaluated in gy the DP/05AR/USAR be increased' (C) May the possibility;of an accident which.is different than any already evaluated in the DP/DSAR/USAR te created; Yes No # (D). Wil1~the probability ot a malfunction of equipnent important to safety previously evaluated in-the DP/D5AR/USAR be increased? Yes_ No k (E) Will the consequences of a malfunction of equipment important to safety previously evaluated in the DP/D5AR/USAR be increased? Yes No > f (T) May the possibility of malfunction of equiement important' to safety different than any alreacy evaluated in the DP/D5AR/USAR be created? T** (c) will the margin of safety as defined in the bases to any 3, y Defueled Technical specificasten to reduced? If.the answer-to any of the preceding is "Yes", an Unreviewed. Safety Question may be involved. Justify tr e conclusion that an Unreviewed i Safety 7Jestion is.or-is not involved. Attach additional pages as' =necessary. '4022I

~ 4 SE 92 564 REV.0 SHEET 3 0F 17 5. Letter, S. Klimbero to US NRC, No. SNRC 1832, dated, August 26,1931 6. Letter, S. Klimberg to US NRC, No. LSNRC 1859 dated, November 27,1991 7. - Cor. trol of Heavy Loads at Nuclear Power Plants, US NRC NUREG CR-0612 -8. Arr.eric.n Naticnal St.ndards Institute ANSI N14.6, Special Lif ting Devices For Shipping Containers Weighing 10,000 pounds or More, and ANSI B30.9 Safety Standards For Cranes Derricks, Hoists Hooks, Jacks and Slings . 9. Shoreham Decommissioning Plan, December 1990 aa supplemented by responses to various NRC questions

10. Supplement to Environmental Report (Decommissioning), December 1990
11. Order Approving Decemniissioning Plan and Authorizing Decommissioning of Facility, Docket No.

50 322, June 11,1992

12. USNRC, Notice of Istuance of En.<!ronmental Assessment (EA) and Finding of No Significant Impact, dated June 5,1992
13. USNRC, Saftty Evsiluation by the Ofti*:e of Nuclear Material Safety and Safeguaro. Related to the Order Approving the Decommissioning ?lan and Authorizing Facility Decommissioning. Long Island Power Authority, Shoreham Nuclear Power Station, Unit 1, Docket 50 322 4

14; SNPS, Fire Hazard Analysis Pepert, (FHAR), Rev. 8, Gated August,1992

15. Nuclear Air Cleaning Handbook, Energy R9 search and Development Administration. ERDA 76 21, 2nd Edition
10. Memorandum, E.F. Montgomery to A.J. Bortz dated May 12,1992, LOM NED 9'.0595 2
17. SNPS Decommissioning Project, Safety Evaluation 92 501, Asmoval and Segmentation of RPV Internals
18. SNPS Decom.1issiun;ng Project, Safety Evaluation 92 505, RPV Cutting and Segmentation
19. Letter, S. Klimberg to USNRC, No. LSNRC 1874, dated December 6,1991
20. _ American N9tional Standards Institute (ANSI); N509, Nuclear Power Plant Air-Cleaning Units and Components: 29.2, Fundamentah Governing the Design and Operation of Local Exhaust Systems
21. National Fire Protection Association: 90A, Standard for the Installation of Air Conditioning and Ventilating Systems; 91, Standard for the Installation o' n:ower and Exhaust Systems for Dust, Sto.:k and Vapor Re noval or Convef ng i
22. Military Standard, MIL STD-282, Filter Units, Protective Clothing, Gar. Mask Components and __

Related Products: Performance Test Methods - DISCUSSION: - -A. GENERAL: -The Decommiss,loning Plan (DP) (Ref. 9), was supplemented by responses to NRC questions (Ref. 5 and 6) and approved by the NRC (Ref.11,12 and 13). DP section 2.2 and 2.2.1.2 (Ref. 9), Indicates that the RPV and its internals will be segmented in three locations to support the decommissioning activities planned at SNPS at the: RPV (in situ), Wet Cutting Station (WCS) and Dry Cutting Station (DCS). The responses to NRC question,11. (11) (Ref. 5), and question 4. iRef. 6) describe in detail the design of the DCS originally submitted in the LP. The original design,-however, has been modified-In the course.of detailed engineering. This SE reviews and evaluates the modified DCS design to be implemented. Differences between the mcdified design and the original _ design described in the DP are also addressed in this SE. The installation of the DCS will be in accordance with specific plant procedures and will be addressed separately. sciense

- -._ -. - - - -.-. ~.-- - - _ - - - - - i l SE 92 5G4 REV.0 SHEET 4 0F 17 i The purpose of the DCS is to provida an enclosure for metal cutting operations that controls the spread of contamination generated during cutting and decontamination of l activated and/or contaminated RPV internals and shell sections. The enclosure will consist of the existing Dry Cutting Station D/S pool walls and floors, an ali-lock entrance and a moveable cot. The controlled environment is achieved by exhausting the air within the DCS enclosure through High Efficiency Particulate Air (HEPA) filters to induce a negative pressure during cutting operations. The components to be segmented in the DCG include the Steam Dryer (SO), Moisture Separator (MS) and RPV shell sections. Several different cutting techniques are i planned to be used for cutting these components. The techniques include thermal cutting using plasma arc and oxy fuel cutting techniques and mechanical cutting techniques such as band saws and grinders. The cutting methods include both remote and manual operations. The cutting techniques and methods have been evaluated and addresscd separately in SE.92-501, (Ref.17) "RPV Internals Removal"; and SE.92-505, (Ref.18) "RPV Cutting and Segmentation". B. SAFETY OF MODIFIED DCS AND CHAN1ES TO ORIGINAL DCS DESIGN 1.) General Safety Evaluation of Modified DCS Design and Operation A general safety review was performed of the modified DCS design and operation to document that nuclear safety considerations and reguletory tortuitements are met. The 1 major aspects of the modified DCS and its operation that relate to safety are: Proximity to safety reiated structures and nuclear. fuel a. b. Handling of heavy loads c.- Handling of radioactive components and generation of airborne contamination d. Use of combustible gases in a confined spaco e. Interface with operable systems These aspects of the modified DCS design and operntion are considered in the following discussion. Key features of the design and operation of the DCS are summarized as to their effect on the public, environmental, worker and plant safety,

a. - The DCS is located in the reacter building (RB) in the D/S pool. This l_ocation precludes any structuralinteraction of the DCS itself with the apont fuel storage pool, or systems related M safe fuel storage.

41so, the effects on Category I structures due to the DCS loads have been analyzed and found in accordance with the original structural design criteria, .mnm

SE 92 564 HEV.0 SHEET 5 OF 17 b. The material handling for the DCS is by the RB polar crane and the existing 1 ton j jib crano "Z" located between the RPV cnd the D/S pool. Lifting and transportation of components to be cut in the DCS comply with the requirements of NUREG CR-0612. Movement of heavy loads over the spent fuel storage cool will be prohibited in accordance with the SNPS Defueled Technical Specification (DTS). The des on and operation of the DCS are thus consistent with the requirements for heavy load movement. The DCS design and operation includes features to limit worker radiation exposure. c. control the spread of contamir.ation, and limit the discharge of airborne contamination from the DCS enclosure and the RB to accatable levels for normal and accident conditions in accordance with 10CFR20, and 10CFR100 requirements. These features and related administrative controls will limit the expected releases and the potential accident releases to the levels described in the DP and in the Supplement to Environmental Report (Decommissioning). The DCS is maintained under negative pressure so that the surrounding RB 'antilation air flows into the DCS to control altborne contamination. The air from 1;.. DCS exhausts through dedicated HEPA filter units that discharge into the RB. Also, two (2) portable 1,500 cfm fumo collection systems with self contained fen, pre filter, and HEPA filter are installed inside the DCS for localized fumo collection to control airborno contamination. Operations of the DCS will be in accordance with plant approved procedures, and under the controls imposed by the DTS, the ALARA program, and the Health Physics Program (HPP). The worker dose estimated in the DP for DCS _activitles is a small part (less than 5%) of the total dose for decommissioning and is bounding for the modified DCS design. The radiological impact to-the environment and the general public from the DCS effluent are shown in the DP and the SNPS Supplement to Environmental Report (Decommissioning) to be acceptable. Similarly, the accident analysis (contamination control envelope rupture) reported in the DP and Supplement to the Environmental Report (Decommissioning)is directly applicable to the modified DCS design; botle the expected release est mate and postulatri accident have been 8 reviewed and approved by the NRC. i d. The modified DCS design and operation are consistent with the need to safely hSndle combustible gases in a confined space. The DCS ventilation system design, controls and instrumentation, and operational procedures are all directed to safely handle combustible gases. The ventilation system is designed in accordance with American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) and the National Firo Protection Association (NFPA) standards. L l. L emm w J

i SE 02 564 REV.0 SHEET G OF 17 Cutting operations are in accordance with plant procedures for firn safety, SNPS Safety Manual for operations in confined spaces, and the Fire Hazards Analysis Report (FHAR). o Operational controls and instrumentation include combustible gas detectors, and gas flow controls that permit flow only during cutting operations. The oxygen and combustible gas detectors are equipped with alarms that activate if thcre is an oxygen imbalance (deficiency or excess) or excessive buildup of combustible gasses. The oxy-fuel cutting technique utilizes a mixture of oxygen and propane. The use of the oxy fuel technique has been evaluated and addressed in the FHAR, Section 1, item G (Ref.14). While no specific accidents are discussed in the FHAR, it explicitly evaluates the use of oxy-fuel gas systems for welding and cutting. Consequences of an oxy fuel accident in the DCS, however, would be bounded by the contamination control envelope rupture accident described in the DP. Fuel usage will be strictly controlled and unused bottles will not be stored on the refueling floor. Use of oxy fuel gas systems is controlled by the SNPS fire protection permit system. Furthermore, appropriate station confined space working requirements will be adhered to. These procedural controls will preclude the accumulation of un surned gaseous fuels and the development of explosive mixtures within the DCS. In addition, combustible gas monitors will be utilized cominuously to detect any combustible atmosphere in the DCS. Also, the RD atmosphere on the refueling floor in the vicinity of the DCS will be periodically monitored for harmful gases. The design and operational controls are considered to be acceptable fer safe thermal cutting operations using combustible gas (propane), The drain inside the modified DCS ;nterfaces with the G11 Liquid Raduste system e. via the floor drain. The interface with the operable G11 system is consistent with the DP and is acceptable. However, the drain will be sealed and no discharge to the G11 system will be permitted. Other features of the modified DCS are noted in the following discussion to further demonstrate the safety of the design and operation. A fire retardant fabric roof material (conforming to NFPA 701 Standards, large scale teating) is used in the cover of the DCS. The fabric roof is installed over a structural steel support assembly. The roof has been designed to withstand the differential pressure [0.125" ( + 0.02") wg] to pmduce the required air changes for containment of aitborno contamination. 8/76.12 4 4i

i r i 1 SE 92 564 REV.0 SHEET 7 0F 17 ~ As described in the DP, the DCS is a non safety related structure. The roof assembly Interfaces with Category I structure (refueling floor). The structural design complies with requirernents for non safety related structures. However, the interaction has been evaluated for the design basis earthquake (DBE) condition. The design is consistent with the DP, and its implementation or postulated failure will not jeopardize the integrity 7 of any Category I structure, system or component. Electrical power supply required to support the DCS operation is provided using modified onsite power circuits. These modifications are temporary and are done in - accordance with the plant procedures. These tempo ary modifications are reviewed and approved in accordance with the plant procedures. Use or postulated failure of . related electric power supply circuits will not adversely af fect any safety related electric j power or control equipment. The modified DCS design meets the intent of the originaldesign and does not adversely affect the operdtion of any Category I structures, systems or components equired l under the defueled condition of the plant. Also, the design does not !ncrease the probability or consequences of previously evaluated accidents, and does not introduco - any new accident. scenario that has not been previously considered. The modified l design does not alter the accident bases considered in the DP, specifically, the contamination control envelope rupture discussed in the DP, Section, 3.4.1.7. - Therefore, it is concluded that the modified DCS design is consistent with the original design intent and will not adversely irnpact the conclusions noted in the Supplement to The Environmental Report (Decommissioning) concerning releases and impact on the general public. 2.)_ Changes to Original Design of the DCS The modified DCS design remains essentially as described in the DP, however, several changes have been included in the modified design to support the implementation activities. The following sections identify and evaluate the differences between the original and modified design intended to be used for implementation. - a. Location of DCS The decommissioning licensing documents (Ref. 5, 6,9,10,11,12,13) indicate. that the DCS will be located on the Reactor Building (RB) refueling floor, north of the RPV. The CCS has been relocated, however, from the refueling floor to the Dryer / Separator (D/S) pool, By relocating the DCS into the D/S pool, the potential for DCS activities to interact with the refueting floor and the spent fuel storage pool in the event of en' earthquake is reduced. This eliminated the need to seismically qualitithe non safety related DCS and also realized cost benefits to the I project. Another benefit is that the relocated design more effectively utilizes the existing facility and equipment. t!25.M 16 41 ) .,,. --..- ~.----_._ _ _ _,_ _m,_,--..-..,

SE 92 5G4 REV.0 SHEET 8 OF 17 The D/S poolis first being used as the location for installation of the Wet Cutting Station '.WCS). After utilization as the WCS the stainless steel D/S poolliner will be decontaminated by routine methods to reduce removable and fixed contamination to acceptable levels for worker access, it is concluded that the condition of the D/S pool, following its use as the WCS, will be ccceptable for the subsequent installation and operation of the DCS. For the above stated reasons,it is conc luded that relocating the DCS to the D/S poolis acceptable. Design Confi uration and Construction Materials 'o. 0 The licensing documents describe the DCS as a pre-f abricated metal building with approxin' ate dimensions of 28' long x 28' wide x 22' high built around a 3 ton capacb.y jib crane with a 24' boorn. The features included a removable roof, a raised floor system with a built-in sump and integral drain, a personnel air lock, slidinD doors, ll0hting, ventilation system and controls and instrumentation. The materials and construction are described as conformin0 to National Fire Protection Association (NFPA) Standards. The modified DCS design differs from the description in the licensin0 documents, as follows: The need for a prefabricated metal building is eliminated because the walls and floor of the D/S pool are available and provide adequate support and contamination control capability when combined with an appropriate roof. No sliding doors are necessary in this configuration, since load handlin0 can be done through the DCS roof. The roof material in the modified DCS design will be made of fabric instead of metal. The fabric, however, will conform to Underwriters' Laboratories and/or Factory Mutual Insuranco standards, and National Fire Protect on Association i standards (NFPA 701, large scale test), and will withstand the negative pressure to be maintained during operation of the DCS Thus, the roof material will safely provide the necessary contamination control capability for proper DCS operation. Also, the toof will be able to open and close, but it will r.ot be removable as was the original roof design. Removability is not a necessary feature of the DCS roof. The dimensions of the D/S pool are approximately 38 feet long by 24 feet wide, and the ioof height will be taprox;mately 27 feet. These dimensions result in a larger DCS volume than the original desl n The increased DCS volume does not 0 affect the normal or accident radioactivity release estimates, however, since the volume of the DCS envelope was not a factor in these calculations. .m n m o_ d I

SE 92 564 HEV.0 SHEET 9 0F 17 instead of a raised floor and dedicated drain, the moalfied DCS will use the D/S pool floor as the working surface. The existing pool drain connection to the liquid radwaste system will be sealed to avoid transfer of water from the spent fuel poo!, which will occur if the drain is opened. Any use of water for decontamination purpose will ti imall enough quantity to be removed using a portable pump. The D/S poN loor provides adequate structural support for loads. Therefore, this arrangement is acceptable. - The relocation of the DCS to the same location where the WCS is installed eliminates the need for a dedicated DCS jib crane. DCS loads will be handled with the polar crane and/or the existing jib crane, located between the RPV and the D/S pool, and all loads will be brought into and out of the DCS inrough the retractable roof. All applicable NUREG CR 0612 (Ref. 7) commitments will be complied with during the handling of these loads. 3 The modified design provides better flexibility for operations, provides more work -area, utilizes existing structure and equipment with only minor modifications, eliminates the need for erection of a pre fabricated metal building, and conformt, to the required codes arid industry standards. Therefore, the configuration and i construct on rr,terials of the modified DCS design are considered to be acceptable. c. General Area Lighting in the DCS The licensing documents indicate that a minimum of 75 foot candies of general area lighting will be provided. The lighting syste.n to be provided inside the modified DCS will average approximatcly 75 foot candles. The lighting in the modified DCS will satisiy worker safety requirements and comply with illumination requirements of applicable codes and standards, such as, the llh minating Engineering Society (lES) and Occupatienal Safety and Health Adminisiration (OSHA). In (,eneral, the area lighting will be consistent with that indicated in the licensing documents, but in. some areas lighting levels will be higher and in other areas will be lower than 75 foot candles. Portable lighting will be utilize to supplement the area lighting on an as needed basis, it is concluded that the lighting in the modified DCS will be acceptable. d. Personnel Air Lock and Escape Hatch t The personel air-lock described in the licensing documents includes two doors, with sight 1ss windows conforming to fire safety requirements, a unidirectional damper ft ie lnner door, and a filter in the ex'erior door mounting wall. (, emman

SE 92 564 REV,0 SHEET 10 OF 17 The modified design includes a personnel air lock that also uses two doors with sight glass windows and *:ornpiles with NFPA Life Safety Code. The entrance into and out of the air-lock uses : adders in lieu of direct step m and step-out at the s6me floor elevation. This was necessary because the modified DCS floor is located on the floor of the D/S pool, and is inaccessible except from the refuel floor elevation. The modified DCS design personnel air-lock meets OSHA standards and is considernd to be acceptable. The rnodified DCS desigr incorporates an escape hatch in accordance with NFPA life safety codes and OSHA standards.This is consistent with the original design. The modified design incorporates all other features pertaining to the personnel ait-lock and escape hatch and, tharefore, is acceptable. s e. Ventilation System The description of the ventilation system included in the licensing documents (Response 11. (11) of Ref. 5) indicates that it will be designed to maintain a negative pressure inside the DCS with respect to the RB. The objective is to control the spread of airborno contamination. The system and components were specified to ANSI /ASME N509 and Z9.2 (Ref. 20), NFPA 90A and 91 (Ref. 21), and ASHRAE standards. The ventilation system as fuither identified in the licensing documents (Response No. 8 of Ref. 6) includes:

1) HEPA filtration unit with a total rated capacity of 4,000 cim, ba0 n and bag i

out filters, and filters capable of filtering particles down to 0.03 microns with ~ an efficiency of 99.97 percent. The exhaust from the HEPA filters will be dischar0ed to the refunling floor

2) two local fumo collection nystems cach rated at 1,500 cfm with self contcined pre-filter, HEPA filter and fan
3) local and remote control panels with visual and audible alarms for fan and filter status with the remote controllocated in the DCS central control station The modified desi n incorporates all the originalventilation system features except 0

for the following differences: The HEPA filtration system configuration is changed to include four units with a capacity of 2000 cfm each, operating in parallel. This capacity exceeds the original single-unit 4000 cfm capacity, and therefore, is adeqLJte. Fan capacity was not a parameter in either the accident or normal release calculations associated with the DCS. However, in order to limit the total activity on the four 424121641

- - - -. ~ - SE 92 564 REV.0 SHEET 11 OF 17 (4) HEPA filters to that of the original single unit HEPA filters, the peak dose rate i for individual HEPA filters has been changed to a limit of 25 Mr/hr (instead of the i originallimit of 100 Mr/hr). The HEPA filter capability is changed to capture particles down to 0.3 microns (vs. 0.03 microns) at an efficiency of 90.97 percent. It has been concluded that the 0.03 micron size was erroneously specified; there is no basis for this specification. The original intent was to specify a HEPA filter that is consistent with the requirement for major air cleaning components used in nuclear ventilation and air cleanup systems, which. typically remove 0.3 micron sized particles (Ref.15). Also, ERDA 76 21, Nuclear Air Cleaning Handbook (Ref.15) indicates that a HEPA filter by definition is specified to remove particles of 0.3 micron size. The change regarding particle size d as not affect the accident or normal release calculations associated with the DCS because the accident release calculation is independent of particle size. For these reasons, the apparent change in the specification for particle size removal for the modified DCS HEPA filter is acceptable. The ventilation system for tl.a modified DCS has been designed to ASHRAE and NFPA standards. The filters have been tested to Military Standard 282 (Ref. 22) in lieu of the ANSI standards The nuclear industry standards (ANSI) are intended for the design and construction of permanent systems in order to ensure continued long term reliability. The experience to date using this equipment for the WCS and RPV in situ cutting operations has demonstrated that the modified design will meet the performance criteria for the DCS. Long term reliability is not a consideration for this temporary facility since it will be in operation for only a few months. The local fume collection systems were initially specified to meet ANSI Z9.2 (Ref. 20). However, this is no longer necessary because this standard is intended for the design and construction of permanent systems to ensure long-term reliability. Mock-up testing will be done to demonstrate that the fume collection system meets all performance and operating criteria. The controls for the ventilation system include manual dampers at the air intake and on the suction side of the HEPA filtration units, Differential Pressure Indicators (DPI), portable gas monitors, portable air samplers, portable continuous air monitors (CAM) and radiation detectors located on the refueling floor. The ventilation system will be balanced to maintain a negative pressure within the DCS with respect to the refueling flour, and is designed to provide 12 (

2) air changes per hour.- DPIs will be monitored to ensure that the operating conditions are maintained during the operation of the DCS, tand will actuate an alarm if excessive negative pressure is experienced. The implementation procedures will include steps to monitor DPIs, gas monitors, and the operation of the filtration / ventilation system for the DCS.

8:3s?9115 41 ~. F ,,,,.,,,,,y .~--%,. +-~-----*w

SE 92 564 REV.0 SHEET 12 0F 17 A singlo local control station will be provided on the refuel floor instead of local and remote control panels. The ori0inal design was based on cutting operations bein0 performed in parallelin the DCS and WCS. usin0 shared cutting equipment and controls in a central remote station. No longer a parallel activity, the modified DCS design uses manually operated controls for the ventilation and dedicated cutting equipment for the remote and manual cutting operations. Consequently, no certral control station is required. f. Transfer of Material to and from the DCS Tiie licensing documents indicate that transportation of all components and segmented pieces to and from the DCS will comply with the requirements of the plant Defueled Technical Specifications (DTS)(Ref.4), and NUREG CR-0612 (Ref. 7). Implementation activities for the transfer of materials are consistent with those indicated in the licensing occuments except that the installed 1 ton RPV/WCS jib crane "Z" will be used in lieu of a dedicated 3 ton DCS jib crane. Lifting and transfer of components will be accomplished usin0 the polar crane and the existing jib crano "Z". Designated load paths will be used for transferring loads to and from the DCS. The plant DTS requirements are applicable and will be complied with. Load drop analyses have been performed in accordance with NUREG CR 0612 to establish the maximum lift height for the jib crane "Z" and load tables have been identified to ensure the structural inte0rity of the D/S pool (Ref.16). Plant procedures will be used for controlling transfer of loads associated with DCS activitier,. Therefore, all material and transfer operations will be consistent with 4 the licensing documents and are acceptable, g. Reduction in DCS Work Scope The number of segmentation activitiee to be performed inthe DCS heve been reduced to the se0 mentation of the Steam Dryer, Moisture Separator and RPV shell sections. Several components originally intended to be segmented in the DCS have bcen segmented in the WCS. These include: jet pump diffusers and risers, core plate, SD/MS guide rods, incore guide tubes, and shroud sections. NRC approval of the added scope for the WCS activities was pursued separately. This reduction in DCS work scope results in a net reduction in the amount of radioactive material tnat may be collected on the DCS HEPA filters, and released from the DCS through the HEPA filter system. { .w.m u l ..~

d SE 92 5G4 HEV 0 SHEET 13 CF 17 h. Ope ational and Health Physics Controls 4 l The licensing documents indicate that during the operation of the DCS, the RB normal ventilation system (RBNVS) will usually be in operation to provide cutside air at 2.5 air changes per hour (Ref. 6 and 12). Continuous Air Monitors (CAMS) and portable alarming area radiation monitors will be used during the operation of the DCS (Ref. 6,12 and 13). Portable air samplers will be used to monitor work l on the refueling floor and the DCS effluent. Radiation surveys will be performed in accordance with 10CFR20,201 during the operation of the DCS (Ref.12). Reactor building ventilat!on and associated effluent monitoring systems will be in operation during decommissioning (Ref.12). The RB standby ventilation system l (RBSVS) and associated HEPA filters will be maintained operable for use in the event of an accident. l Comnonent segmentation procedures will contain measures, to ensure adequase ventilation and prevent the accumulation of combustible gas. These measures include: 1) gas cylinder valves will be shut off whenever cutting operations stop, l 21 the DCS ventilation system must be in operation prior to personnel entering the DCS and before any cutting operations begin, and 3) oxygen and combustible gas monitorin0 instrumentation will be monitored prior to personnel entry and dur!ng j cutting operations. The above noted controls, to be implemented with the modified design, are j consistent with those included in the licensing documents and, therefore, are j considered acceptable, i i C.

SUMMARY

Installation of the non-safety related DCS will require temporary modification to the refueling floor, which remains a Category 1, safety related structure. A separate safety evaluation will be performed for the procedures for installation of the DCS. Per ECR H 1502, Rev. 8,_ (Ref. 2), the_ D/S poolliner has been downgraded from Category I to Category 11. The modified design will not adversely impact the integrity of safety relateJ structutes, systems ai components of the defueled plant. B "2512 16.41 4 - -.-..m.. -. .--~

SE 92-564 miV.0 SHEET 14 OF 17 SAFETY EVALUATION PART A - Review of the US AR/DSAR The decommissioning licensing documents identify the design of tho DCS as non safety related. The USAR/DSAR does not directiv address the design of the DCS. However, chapter 3, of the DSAR addresses the classification of the D/S pool and identifies it to be Category I. The DSAR Table 3.21 lists the D/S pool and the liner as Category I items. However, ECR H-1502, Rev. D, downgrades the liner to Category 11. The DCS involves on'y temporary modifications; therefore, no change to the USAR/DSAR is required. Part B - Review of the Defueled Technical Snecifications The Defueled Technical Specifications (Ref. 4) do not address the operation of the DCS. Controls for the polar crane (and designated load paths) that are incorporated in the DTS are applicable for any DCS usage. Such use will not affect the Polar Crane operability. The rrodified design of the DCS does not affect the operability and surveillance of any other system required under the defueled condition of the plant. Therefore, the modified design of the DCS does not require a change to the station Defu6 led Technical Specifications (DTS). EART C - Rayiew of the Decommissioninn Plan The Decommissioning Plan (DP) Sections 2.2.1.2, 3.2.1, 3.4, and 3.4.1.6 as supplemented by responses to NRC questions (Ref. 5 and 6), hwe been reviewed. The differences in the design of the DCS have been reconciled und evaluated to be acceptable. The DP will be updated to incorporate the changes. The implementation activities associated with the design of the DCS will not result in environmentalimpacts different from and exceeding those set forth in the Supplement to Environmental Report (Decommissioning) s..ef.10) for the following reasons:

1. There is no increase in the amount of radioact ve

. fluent released to the i environment during decommissioning

2. There is negligible,if any, addits.at radiation exposure to svorkers beyond that previously identified for decommissioning
3. There is negligible, if any, additional radioactive waste generated Seyond that previously identified for decommissioning I

i 8 % 2216 41

I SE 92 564 REV.0 SHEET 15 OF 17

4. Operation of the modified DCS wili not introduce any new or increased hazard which could result in the previously postulated accident impacts being 4

exceeded S. Non radiologicalimpacts such as air quality, land and water use, noise and - i dust will not be increased because the work is confined within the Reactor Building ILAST D. Unreviewed Safetv Question Evaluation -(A) The probability of any accident previously evaluated in the Decommissioning Plan or USAR/DSAR will not be increased as a result of the modified DCS design because the design of the DCS is conslatent not only with the requirements for non safety related structures, systems and components, but also, with the accident description in the DP. Also, implementation of the design of the DCS 1 will not adversely affect any safety related structure, or operable, or functional t systems. The design criteria for the DCS is consistent with tha accident analysis in the DP. NOTE: Peak radiation level for HBPA filter change out is changed frorn 100 mRom/hr to 25 Mrom/hr. (B) The consequences of an accident previously evaluated in the Decommissioning Plan or USAR/DSAR will not be increased for the reasons rpecified in item (A), above. (C) The possibility of a new or different accident from those already evaluated in the Decommissioning Plan or USAR/DSAR will not be created for reasons specified in item (A), above. (D) The probability of a malfunction of equipment important to safety previously evaluated in the Decommissioning Plan or USAR/DSAR will not be increased by the installation or operatiot, of the modified DCS. The floor drain from the DOS will. l be scaled to isolate it from the plant liquid radwaste system. Therefore, the liquid radwaste system will be unaffected by the installation of the DCS. p (E) LThe consequences of a rnalfunction of equipment important to safety previously o evaluated in the Decommissioning Plan or the USAR/DSAR will not be increased u i-for reasons specified in item (D), above. L (F) The possibility of a tralfunction of equipment important to safety different from l those already evaluated in the Decommissioning Plan or the USAR/DSAR will not i be' increased for reasons'specified in item (D), above. l: nasusu -nmvmec, .,,,-e.,, m ,,,,,,,emme----aww,m, _ _ an,-m,.,,_wm,n,- c wwm,,,,,,,wwwv.a m v rww awnn w w w-w r 0 v w' '*w "~m M W-

SE 92 564 REV.0 SHEET 1G OF 17 (G) The margin of sefety as defined in the bases to any technical specification will not be reduced because the DCS system will not affect any fuel storage or handling equipment or other equipment addressed in the Defueled Technical Specifications. (H) The differences between the modified design of the DCS and the design described in the DP have been evaluated and will not constitute any unroviewed safety quesdon. PART E - Safety Slanificance All structures, systems and components, astociated with tha design of the UCS are classified as OA Categury 11 and Seismic Category N/A in accordance with Table 3.2-1 of the DSAR, Rev. 3. The implementation of the modified DCS is considered temporary and wiil not adversely affect the operation of Category 1, safety related structures, systems and components. The accident scenarios addressed in the Decommissioning Plan are still valid and the implementation of the modified DCS will not introduce any new accident scenario. The effect of the non safety related DCS on Category 1, safety related structures, systems and components is considered to be insignificant. The interaction of the non-safety related DCS on safety related structures, systems or components during its operation has been reviewed and found to be acceptable. A separate safety evaluation wili be performed concerning the installation of the DCS. PART F - Radiolonical Imoact The activities to be performed in the DCS are included in, or are radiologically 'counded by the accident and normal radioactivity releases presented in the Decommissioning Plan. All radiological impacts have been addressed in the Decommissioning Plan Section 3.0 and 4.0 and supplemented by responses to NRC questions. The off-site releases are monitored and the operability of the existing HEPA filters in the RBSVS exhaust trains will be maintained. The modified DCS design will not increase L the radiologicalimpact on the public. These activities do.ot involve the addition of any radioactive material to the plant. In addition, HP contamination and exposure control measures will ensure that these activities will not result in an increased risk of exposure to_onsite personnel. Therefore, there will be no radiologicalimpact to the offsite general public which exceeds the radiological accident / malfunction analyses - presented in the DP/DSAH/USAR. u.-m. c

g SE-92 564 REV.0 ,.2$ SHEET 17 OF 17 AIrACHMENT " A" ~ Eh AM DECOMMISSF41NG PROJECT (]... SAFETY EVALUS. TION CHEEMSI In.hY&fb : h' "' SAFETY EVALUATION No._S.f-92-564 Rev. Q -A WM Q' The safety evaluation, SE-92 564, Rev. O cc w '. hat the modif:cd design of the ~1 DCS does not involve ar9 unreviewer

a. The diffe: 3nces in the modified DCS design from thm presented i-

"e been evaluated to be acceptable. However, a revision to the DP is rc .t those difftaences. A copy of the safety evaluation will be provided i > .e L/hCD indicating that revision to the DP is required. A voluntary change notice (VCN) will be issued as part of the implemente., of the revision to the DP. Section 2.2.1.2 of n c D,2 anc supw:nentary information provided in the LIPS -nsponses to the NAC questions, ll.;ils,11.(15) Ref. (5) and 2,8,18 and HP 2 (Ref. 6) be revised as requireu and incorporated into the DP. ~ s t: N O $!)s/971% 41 . ~.. ~~

. -. - ~. - .. ~... MEETING MINUTES Site RAview Committee Meeting Date IssucJ Attendinn: L. Hill, Chairman _ A. Bortz,'Vice Chairman E.' Montgomery, Menber N. Nilsen, Member F. Petschauer,. Member -J. Wynna,-Member .R. Bernard, Guest-- S. Rao, Guest C. Adey, Guest T. Garvey, Cuest A..Zegel,' Guest-V.~Demers, Guest D. Holm, Guest Mqedinn Called to Order by Chairman: Date: ' August 25, 1992' - Time: 3:00 P.M. Meeting; 92-069 -,A_Dproval of Previous Minutes: N/A New Items ~ 92 069 001 ' Reviewed Safety Evaluation SE No. 92-564 Rev. O, Design of Modified DCS. Based upon a presentation by C.. Adey,. Decommissioning Dep artment, this procedure has-been reviewed in accordance with 10CFR50.59 and SRC has determined that there are no uersviewed safety questions..This item does not reaul t in environmental impacts different from and exceeding those set forth in the licensee's Supplement to Environmental Report -December 1990. This_ procedure _was Approved as revised. Tho' committee noted that the safety evaluation addressed, in considerable detail, the worker Safety hazards associated-with combustible _ gas acoge in a . confined space. The committee established that during oxyfuel cutting, the quantity of propane ga-in use_ will be very small, most likely less then one-bottle . 3 .for any cut. Further, _ no storage of combustible gas within the Dry _ Cutting Station, will be permitted. ~ Thus, this effectively limits the explosion hazard. Item Closed Y m,e. e-.

.. -. ~.... -.. - - - - -. -. - -2_-- + 92-066-002-Reviewed Temporary Procedure TP 86X705.15 Rev. O, SPCN No. 92X05E2, Incore' Guide Tube Removal & Segmentation. . Bared upon a presentation by T. Garvey, Decommissioning Department, this procedure has been reviewed in accordance with 10CFR50.59 and SRC has determined that there are no unroviewed safety + questions. This item does not result in envirotunental impacts different from and exceeding those sc forth - in the licensee's Supplement to Environmental Raport December 1990'. This procedure was Approved. Item Closed 3 Meeting Adjourned' by Chairman: Time: 4:00 P.M. s Approval of Minutes: [/ ~ Chairman 1 ?- i, 1 5 { h a 1 is y 4 YT F w f T +-- -'w-

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