ML19323A908

Mini Decay Heat Removal Sys Design Criteria, Revision 8

ML19323A908
Person / Time
Site:	Crane
Issue date:	04/25/1980
From:	Dunford E METROPOLITAN EDISON CO.
To:
Shared Package
ML19323A907	List: ML19323A906 ML19323A908
References
NUDOCS 8005060281
Download: ML19323A908 (17)

Text

{{#Wiki_filter:._-. s o o o g o 2. g f. s 3 .~ s j 1 THREE MILE ISLAND - UNIT NO. 2 MINI DECAY HEAT-REMOVAL SYSTEM DESIGN CRITERIA e ]. e. REVISION DATE PREPARED BY APPROVED BY l A 7/10/79 E. C. Dye B. D. Elam j 1 [ 2 s/al/79 gg y 3 8/16/79 (,C, gg Q y r 4 9/10/79 (#,C1,uG. gZ 5 9/20/79 (' C.,

AGjg,

,u

t T V l THREE MILE ISLAND - UNIT NO. 2 i I MINI DECAY HEAT REMOVAL SYSTEM ~ DESIGN CRITERIA 1 1 1 (- I .i 1 i REVIS10N' DATE PREPARED BY APPROVED BY 6 10/3o/79 (I.) f[% MGhkht/ tot o!/[5/so 8 h >gn p,~ 1 t ,_... _ __ _. ~ -

e. MINI DECAY HEAT REMOVAL SYSTDi DESIGN CRITERIA 1.0 SCOPE This document establishes the design criteria for a small scale decay heat ~ removal system to be used to cool the reactor core,for three years. The system consists of a pu=p/ heat exchanger'subloop to be in-stalled in parallel with the existing decay heat system and in paral-lel with the Westinghouse designed Alternate Decay Heat Removal Sys-tem. The system will be used to remove decay heat from the reactor core until full defueling has been performed.

2.0 INTRODUCTION

The reactor coolant system is currently in a natural circulation mode with heat being removed through Steam Generator "A" in a steaming ( mode. In order to reduce the vulnerability of the plant cooling mode, a force circulation system with a minimum of supporting systems is e preferred. A small scale decay heat system capable of removing the small amount Wl of decay heat remaining (5;l MW) in the U' nit 2 core will suit this purpose. All system components shall be enclosed in the existing Unit 2 Fuel Handling Building or Auxiliary Building to minimize the poten-tial for release of radioactivity to the environment. 3.0 FUNCTIONAL AND DESIGN REOUIRIMENTS 3.1 Performance Reouirements 3.1.1 The system shall recirculate reactor coolant through 1 the core for removal of decay heat. The ulticate heat sink shall be river water with the Nuclear Ser-vices closed cooling loop to transfer heat from the reactor coolant to river water. i

O 3.2 Applicable Codes and Standards Piping shall be: Manufacturing Installation Description Code Code Connection to the decay heat ASME - ANSI system downstream of DH-V3 Section III B31.7 up to and including the Class 2 Class 2 first isolation valve. Connection to the decay heat ASME - ANSI system downstream of DH-V3 Section III B31.7 from the first isolation Class 3 Class 2 valve up to and including the second isolation valve Connection to the decay heat ASME - ANSI system upstream of DH-V4B Section III B31.7 up to and including the Class 2 Class 2 second isolation valve Connections to the existing Nuclear Services closed cooling g ,g system (~ piping up to isolation valve ANSI B31.l* ANSI B31.1* -i isolation valves ASME - ANSI Q. Section III B31.l* Class 3 Balance of pip'ing ANSI B31.1 ANSI B31.1 6 Heat Exchangers ASME - Section VIII TEMA Standard (ASME Section III -if available) Pumps Hydraulic Ins titt'te Standards (ASME Section III if available) Filter ASME - g4 Section VIII Seismically supported for Category I loadings blev 5 y ? UWi.W"eW: WW** ::. :.'sM":..6*:.M >.WV' * ~M. - ;n*f. - 2.,,:3 M...:';. S ~~.2'.~ ".~~f'?~~S?*.h*'M ' '.4 '..,.; ;,.. . ;^ ^ ..y. .s n.. ..v ..w r.. +1..::,'.f7.',*. ~.* t) V; '-l * '.: a. * ,' # *? -:Ii':' ' i - ' " * U '

~ i r * *

~ "- 'l 3.3 Design Basis 3.3.1 The portions of the system that are ANSI B31.7 Class 2 shall be seismic Category I. The remaining portions of the system that convey reactor coolant shall be ds-Fv._v 3 signed to operating basis-earthquake (0BE) lo' ads. The balance of the system can be designed as nonseismic. except the flSCC tie-in lines up to the isolation valves shich shall be category I seismically supported. _n 3.3.2 The system shall be designed to operate' with a loss of offsite power. .~ .m. s e e' S 9 O 3_

3.3.3 The system shall be equipped with test and instru-mentation connections for system pre-operational testing and normal operation. 3.3.4 The system shall be designed to supply cooled reactor coolant water to the RCS through the Decay Heat In-jection lines and receive heated coolant through the Decay Heat return lines. 3.3.5 The system design shall employ all welded connections to the greatest extent possible to minimize system leakage. All two inch and larger piping shall be welded except flanges at equipment connections. All ~ connections to the process piping shall be welded or screwed with seal weld up to the root valve. Rev. 2 3.3.6 The piping system and equipment shall be provided with, adequate vent and drain connections. 3.3.7 The system design shall minimize,the use of auxiliary support systems (bearing cooling water, lubrication i oil and instrument air). Loss of instrument air shall not change the operating parameters (flow and te=pera-l ture) of the system. 3.3.8 The system shall be designed to remove the required heat load at the temperature of the cooling. water l shown in Section 3.4. 3.3.9 The system shall have provisions for the future in-sta11ation of a water purification system with the capability (resin disposal and shielding) to handle radioactive water. Installation and startup of this equipment shall not interrupt system function. .g.

= 1

• N.

3.3.10 The system shall be provided with proper oderpressure re-lief devices. The discharge of the overpressure relief devices shall be piped such that they minimize the spread of contaminated fluids ano shall be provided with some Rev 5 means of visual indication of leakage. 3.3.11 ne sys te '/shall have proper connect'-lens and 6the r provi-sions for flushing of new piping and cc.sp'onants prior to startup. I'eu piping and components shall be in a clean and neutralized state when installed.' Checical cleaning shall not be ' used af ter installa tion. 3.3.12 Trovisions shall be.ade to handle system 3cakage or drainage such as pump seal " leak-offs, flanges, and valve stees. Consideration shall be given to containing both gaseous and liquid ef fluents, and safely delivering the vastes to GPU approved processing spstems. O 3.3.13 A recircula tion line to meet the startup flow requirecents Rev. 2 of the pumps shall be provided. A, system recirculhtion line is, acceptable for this service. fEev. 3,,. 3.3.14 ne system shall be designed for long-term continuous cool-ing for a minimum of three years. 3.3.15 For 1 icreased system availability considerations, the sys-tem shall have redundant heat exchangers and pucps. cm 3.3.16 Tne system shall be designed to be isolated f rom the er.ist-ing plant sa fe ty sys t ees. Tne systee, then in the isolated ] 7-ode, shall not jeepardize the operability 'or pressure in-R tegrity of the existing plant safe ty sys tees. Tne isolz-tion from the Decay Heat Kamoval Syst ee shall be -i th double iso 3 a ti on valves. _. I. g 3.3.17 The system shall have provisions for remote isolation, draining, and flushing to minimize radiation exposure to maintenance personnel _.

i 1 i j j 3.3.18 The MDHR System Design shall include a filter which will be located in the supply line to the MDHRS. The Rev. 8 filter will be replacable, and will be replaced should plugging occur and filter bypassing not be technically acceptable. i J l I I l i l-4 i .j. i j I 4 I 1 ) 4 J \\- 1 L

e 3.4 Sizing Requirements 3.4.1 The system shall be designed to meet the following requirements: (a) Flow through reactor core 120 to 175 gpm (b) System inlet. temperature 180* F (c) System outlet temperature 130' F (d) Design Pressure (<.nd Coolers and pump suction 235 psig 6 Pump and discharge piping 235 psig Rev. 2 (e) NSCC water temperature 100* F (maximum) (f) "NSCC water flow rate 200 gpm (g) Heat Exchanger duty See Curve 1 3.5 Layout Requirements 3.5.1 The system equipment shall be located to facilitate t construction and future modifications and ease of access during operation. 3.5.2 The system flow path shall consist of cooled reactor coolant entering the Decay Heat Removal System up-stream of valve DH-V4B, flowing through the reactor core and returning back to the heat exchanger through the' Decay Heat Removal drop line and the new system connection downstream of DE-V3. On the cooling water side, the Nuclear Services closed cooling system shall be connected to the shell side of the new Mini Decay Heat Exchanger (refer to Figure 1, attached). 3.5.3 The ultimate heat sink shall be provided by the Nuclear Services River Water System. I I 3.5.4 Radiation shielding shall be provided between the pumps and other equipment and piping to tainimize the radiation exposure to maintenance personnel while working on either of the pumps. This shall include shielding between the two pumps. Radiation Shielding and reach rods shall be provided to minimize the exposure to operating personntil when Rev. 2 realigning system valving. Rev. 6 Rev. 7 l i _g.

• 6 E... i r

...qt ? * ~ u i c : :.:: pts _ 3.6.1 All equi;::.2nt shall be located it.iide ths Fuel Fandlir.g Buildinc and.'uxiliary Building. 3.6.2 Consideration shall be given to the integrated radia-tion exposure to all sensitive materials (electrical equipment, elastomers, etc.) over the design life of the system. If equipment cannot be satisfactorily shielded, the materials shall be com)atible with expected expo-sure. 3.6.3 If area radiation levels at the pumps are expected to i inhibit routine maintenance operations on the pumps, consideration shall be given to provide remote bearing lubrication to the pumps and motors. 3.7 Sampling Reouirements Connections shall be provided for future sampling lines. 3.8 Materials Requirements All wetted matirials shall be compatible with fluids having water chemistry specified in Section 3.12. It is expected that 1 austenitic stainless steel type 304 or 316 shall be,used. l Red 3.9 Electrical Requirements 3.9.1 Electrical equipment shall be capable of being started b " I and powered from an on site lE diesel generator set in ~ the event of a loss of off site power. Loads shall be sequenced on to the diesel generator set manually. 3.9.2 Electrical classification of the system is non-lE, however the electrical power to the operators on the system isola-Dav. 5 tion valves and the pump motors shall be class lE. The instrumentation shall be powered from one class lE bus. _g.

3.9.3 Motor rated starting voltage shall be verifici and ccnsistent i with the voltage regulation capability for the diesel generator to be used. Motor feeders shall be protected consistent with the original plant design and the normal trips for overload, etc., shall be used. 3.9.4 Electrical Load list: will be provided in the system I description. Rev. 5 3.9.5 " Criteria for General Modification to the BOP Electri-cal System" are applicable. Also, refer to " Criteria for Loss of Offsite 80P Electrical Power'.'. 3.9.6 The power supply to the pump motors shall be supplied from separate lE buses. 3.9.7I The Mini Decay Heat Removal pump motor power supplys are to be interrupted when the installed decay heat remov-Rev. 5 al pumps are started. This provision shall not inhi- ~ L bit the rperation of the decay heat p' umps. 3.10. Testino Requirements ~Provisic shall be made for pre ' operational testing of the sys- \\ i \\ tem, including hydrostatic tests, flusning or-new piping, and deinonstration of required pumping capability. 3.11 Ins trumenta tion and Control Requirements 3.11.1 Tne system shall be designed to provide instrumentation to monitor functional performance requirements, includ-ingbutnotlimited(o: '(a) Pump discharge pressure 0-300 psig ~ (b) Heat Eschancer inlet and outlet 50-2500 F e ~ _le-

i (c) Flow Rate Nominally 120 gpm Maximum 200 gpm (d) N.S.C.C. inlet and outlet Temperature 50-1500 F (e) Pump Suction Pressure 0-200 psig R ev. 2 3.11.2 Control circuits for existing egipment shall be re-viewed to ensure that no spurious automatic, or interlock signals will' cause incorrect operation of the system. 3 11 3 Provisions shall be made for installation of controls and remote indicators in the Unit 2 Control Room. Controls and indicators shall be located in the new control Rev. 7 panel,provided. 3.11.4 Control shall be manual. ThE, pump control switch shall have star _t, normal, stdp and spring ~ return to Rev. 3 normal positions. Run/off indicator lights shall be provided for motors and open/close lights shall be provided for the system isolation valves. (Both ' lights shall be on when valves are in intermediate position). 3.11.5 Control cables should have 50%, and preferably 100%, spare conductors to allow for futbre nodifications. T 3.11.6 Loss of system flow shall be alarmed locally and in the.Tain control room. i 3.11.7 sDeistec-) g g,4 i 0.

l 3.11.8 The isolation valve (s) on the SSCC system shall automatically close on detection of a leak, i.e., imbalance in the flow to and from the Mini Decay Heat Removal cooler. 3.11.9 Area radiation monitors shall be provided and shall alarm on the local control panel and in the Control Room. 3.12 Water Chemistry pH 7.5.- 9.5 (nominal 8.5) Boron 3000 - 4000 ppm Bydrogen 5-40 cc/Kg (nominal l 15-40 cc/Kg) lev. 2 Chloride <4 ppm Fluoride <1 ppm Dissolved Oxygen <~ 0.1 ppm I t l l i i . l

"Mi^ll " DECA Y HEA7" REMOVAL S YS 7~EM DH V3 flGURE / TO DECA Y HEA T $_. /2 x }_ y _T PUMP SUC TION LO"*- DHA-Vol I C<}- - ~ To Y1 A DHR MDH-fl ,n, MDH-V3s MDH-V36 N-2 N-3 N3 NNS g-!?_d }-_$0. - -. --. _ _ _ FROM DECA Y HEA T Co LER Lg yyy.,y L- - - HA-V078 D D<1-- - FROM W ADHR RB -H-H-il FUTURE CLEAN UP SYSTEM TIG-IN I X N.2 NNS ~ O ,g s- - - -N-q NS c c p - - -N- - - -i .g 'g Tr m@X X@ r +MDH-VilA x X MINI DECA Y HEAT MDHR PUMPS REMOVAL COOLERS [ \\ M= X Y X MDH-Vil8 Y S- - - -y- - s yScc --->y---f FUTURE CL EAN UP l, u 44__ SUB SYSTEM

" MINI " D ECA Y HEA7" REMOVAL SYS TEM c- - - - - ' l NSCC SYSTEM coNNEC TION ' - r-(5 I r/pg 2 I l i l W REV. I 7-/9-79 l REV. 2 8-I-79 N l REV. 3 9-/O-79 I i Rev. 4 7-zt-79 i l l , 3 - - -- -,- - - /' s i s .L / i l-

uJ e

s l g___4 g \\ j p _ __ q k----g / \\ l 's / N I / I g- %.L s/- .- -._ _.%'.,.L./ ~ M F -~ MINI DECAY HEAT Y REMOVAL COOLERS g lf y 70 ,7'g--_.-- 3-.Ts FROM / i f ,s / N si s NSCC SYS. N }- - - -1 tlSCC SYS. l---4 V N d-- s \\ l s./ I / s uns u---_u--- u uns s Y4-- NOTES : O NNS '831. I (NoN NUCLGAR sneery) @ S - 831. / SGISMIC/lLL Y sumoar 208 sete s

l l l l' r = = de T , d" as a E2 e ca is . 4 53 - 3 N N E*$$E N 2: .[ 3***{ l 9 -= " 9" l s e ~~=~ Q, ) i =.: _ - t ) =-

--

• ~3E:y R

ect t 2 t* *. 2 3 A8 = 7 a /I = l 23 23 Y, i N g n 9 -{ S -3 v 3.. E I 'd M o S / l ~ z = l =, / / =s I. / a1 / 2 j /

s

/ / R4 2 = a o g g

g. ~,....mx -

1 +9

• }}