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PS~G Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038-0236

Nuclear Business Unit

JUL 011996 LR-N96191

United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

· SUPPLEMENTAL INFORMATION RADIOLOGICAL DOSE ASSESSMENT METHODOLOGY SALEM GENERATING STATION NOS. 1 AND 2 FACILITY OPERATING LICENSES DPR-70 AND DPR-75 DOCKET NOS. 50-272 AND 50-311

Gentlemen:

This letter is being se:r:it to provide information to the Staff pertaining to the radiological dose assessment that was performed in support of a requested change to the Technical Specifications on Control Room Emergency Air Conditioning ·.System, (ref. LR-N96154, dated June 10, 1996). The attached information was requested at the June 26, 1996 meeting held between the NRC and Public Service Electric & Gas Co. on the subject license change request.

The attached pages provide input assumptions, data and results pertaining to a postulated fuel handling accident inside the Fuel Handling Building and Reactor Coolant Pump locked rotor accident. Similar information on the LOCA analysis, the bounding accident, was submitted in an earlier supplement dated June 24, 1996, (ref. LR-N96178).

The attached information eliminated non-relevant information on the Exclusion Area Boundary and Low Population Zone doses which are not pertinent to the Control Room dose analyses, but were part of the calculations performed.

If any further information pertaining to this supplement is needed, please call.

Sincerely,

- ---- -- ---.,

£JR 11~(( D. R. Powell Manager -

/ ·' 4001/

? Licensing and Regulation

The power is in your hands. 95-2168 REV. 6/94

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Document Control Desk LR-N96191

Attachment

2

C Mr. T. T. Martin, Administrator - Region I U. S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406

JUL 011996

Mr. L. Olshan, Licensing Project Manager - Salem U. S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Mail Stop 14E21 Rockville, MD 20852

Mr. C. Marschall (X24) USNRC Senior Resident Inspector

Mr. K. Tosch, Manager IV Bureau of Nuclear Engineering 33 Arctic Parkway CN 415 Trenton, NJ 08625

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• •6010.65 STONE & WEBSTER ENGINEERING.RP.ORATION CALCULATION SHEET CALCULATION IDENTIFICATION NUMBER

J.O.OR W.O.NO. DIVISION & GROUP CALCULATION NO. OPTIONAL TASK CODE

02560 UR(B) 010 • 0 NIA

1.0 Objective

PAGE 5

The objective of this calculation is to determine·the radiation doses ' . in the control room following a Reactor Coolant Pump (RCP) Locked Rotor Accident (LRA) with the modified control room ventilation system. The calculation assumes a simultaneous Loss of Offsite Power (LOOP) following the high radiation alarm signal generated by the control room intake monitors, with the subsequent delay in switching from the normal operation mode to the emerg::mcy operation mode of the control room ventilation system. The calculation utilizes the automatic selection capability of the radiation monitors to select the less contaminated CR intake. In addition, it assumes that only one Unit's CR emergency ventilation system is available.

Additionally, control room operator doses are calculated for a case that assumes the control room is already in the emergency ventilation mode when the accident occurs.

The control room doses determined in this calculation for LRA include only the contribution from the airborne source inside the control room.

This calculation also determines the process safety limit for the control room air-intake monitors.

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• e STONE & WEBSTER ENGINEERING CORPORATION .. 5010.65 CALCULATION SHEET CALCULATION IDENTIFICATION NUMBER

J.O.OR W.O.NO. DIVISION & GROUP CALCULATION NO. OPTIONAL TASK CODE

N/A 02560 URIS) 010 - 0

3;0 Assumptions

1.

2 •

Iodine partition coefficient in SGs is assumed to be 0.01.

The assumption of iodine partition coefficient in the SGs of 0.01 is appropriate for the portion of the primary leakage which do not flash. The P-S leakage of 1 gpm will not cause flashing when the steam generator tubes are fully covered with water.

The X/Q values for the more favorable intake are used when the control HVAC is in emergency mode, taking credit for the automatic selection of the more favorable intake by the control room radiation monitors.

3. The time for the control room EACS Fans to reach full speed after re-start is assumed to be 15 seconds.

4.

5.

The unfiltered inleakage after control room is pressurized due to ingress/egress is assumed to be 10 cfm. The unfiltered inleakage after control room is pressurized due to ductwork is assumed to be 50 cfm.

PARAMETERS ASSUMED FOR MONITOR RESPONSE TIME

Time constant - Table 6-1 of reference[ll] Response data - 2.7E7 cpm/(µci/cc) for Xe-133

1.2E8 ~pm/(µci/cc) for Kr-85

The monitor specific time constants are not available at this time. The values in Table 6-1 of ref.[11) for SE RM-2000 -· smoothing algorithm with filter constant equal to 6 are used. The specific detector response data are also not available at this time. The

PAGE 9

[Ref.1]

[Ref .1]

[Ref.1]

[Ref .1]

[Ref.11] [Ref .12]

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• 9· STONE & WEBSTER ENGINEERING CORPORATION •5010.65 CALCULATION SHEET CALCULATION IDENTIFICATION NUMBER

J.O.OR W.O.NO.

02560

DIVISION & GROUP

UR!BI

CALCULATION NO.

010 - 0

OPTIONAL TASK CODE

N/A

Calculation conservatively uses 50% of the values given in Table 2 of SE calibration report E-255-1332 (Ref .12] for a typical beta in-duct detector RP:-25A in a 55 gallon drum.

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CALCULATION IDENTIFICATION NUMBER

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02560

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UR(Bl

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f,Q Data

1.

2.

3.

4.

5.

6.

7.

8.

9 •

Fraction of failed fuel after the accident 5%

Fraction of the fuel activity in the gap 10%

The gap activitr of the failed fuel that is released to RCS (0.5% of the core inventory) is presented in.Table 1.

The initial primary. coolant activity including pre-accident iodine spike is given in Table 2. The initial secondary coolant activity is also given in Table 2.

Primary to secondary leak rate 1 gpm

Primary coolant volume - 10,892 cubic feet

Steam releases

O - 2 hr - 654,600 lbs 2 - 8 hr - 540,300 lbs 8 -32 hr - 2,161,200 lbs

Post-accident steam generator liquid mass 106,860 lbs for each ste~m generator

PAGE 11

(Ref.1]

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CALCULATION IDENTIFICATION NlJMBER

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UR(BI

CALCULATION NO.

010 - 0

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10.

11. Control room intake X/Q's (from Unit 2 MSSVs) Unit 1 intake Unit 2 intake

(Slm3 l ( s lm3 ) 0-2 hr 1. 96E-3 4.17E-3 2-8 hr 2.13E-3 1.00E-2 8-24 hr 1. 80E-:3 8.32E-3 1-4 day 1.25E-3 5.54E-3 4-30day 7.46E-4 3.09E-3

Unit 2 accident will result in greater doses because of worse X/Q values.

12. CONTROL ROOM PARAMETERS - Modified design

* control room pressure envelope volume: 81, 420 ft3

* Normal unfiltered air intake rate: 1200 cfm

* Filtered emergency makeup flow- 2500 cfm * Total unfiltered inleakage- 60 cfm

(10 cfm from ingress/egress; 50 cfm from Ductwork leakage; see assump~ion 4)

* Filtered recir flow rate 5500 cfm - one EACS fan operation 13,500 cfm - two EACS fans operation

* Intake and recirculating filter efficiencies: Elemental iodine - 95% Organic iodine Particulate

- 95% - 95%

PAGE 12

(Ref .1]

(Ref.1]

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02560

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STONE & WEBSTER ENGINEERIN.ORPORA TION CALCULATION SHEET

CALCULATION IDENTIFICATION NUMBER

DIVISION & GROUP CALCULATION NO. OPTIONAL TASK CODE

UR(BJ 010 - 0 NIA

Control room occupancy factors: Time from Start Occupancy ·Qf A~ciaent :Ea~:tQt:lli 0 to 8 hrs 1. 0 .. 8 to 24 hrs 1.0 1 to 4 days 0.6 4 to 30 days 0.4

* Breathing rate - 3.47E-4 m3/~ec

13. The control room intake damper closure time: 20 seconds.

14·. The time for the diesel generators to become fully operational after LOOP:. 13 seconds

PAGE 13

[Ref.1]

[Ref.SJ

[Ref.l]

(Ref.1]

'":· • STONE & WEBSTER ENGINEERIN-ORPORATION CALCULATION SHEET CALCULATION IDENTIFICATION NUMBER

\ J.O.OR W.0.NO. DIVISION & GROUP CALCULATION NO. OPTIONAL TASK CODE PAGE 14 02560 URCBJ 010 • 0 N/A

Table 1

Gap activity in the Failed Fuel* (Ci)

Nui:;lid~ Activity Il31 4.95E+5 Il32 7.00E+S Il33 l.-OOE+6 Il34 l.10E+6 Il35 9.50E+5

Kr85m l.30E+5 Kr85 5.50E+3 Kr87 2.35E+5

_,,.- ...... Kras 3.35E+5

Xel3lm 3.50E+3 Xel33m l.45E+5 Xel33 1. OOE+6 Xel35m 2.00E+5 Xel35 2.50E+5 Xel38 8.00E+5

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* From Ref. ( 1] . ..

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• STONE & WEBSTER ENGINEERINIO~P~RATION CALCULATION SHEET CALCULATION IDENTIFICATION NUMBER

DIVISION & GROUP CALCULATION NO. OPTIONAL TASK CODE

N/A URCBl 010 . 0

Table 2 Primary Coolant and Secondary Coolant Activity*

. (Ci)

PAGE 15

Primary Coolant with Pre-accident Iodine Spike

Secondary Coolant 4 Steam Generators

H:UQlide · .A!:;tiYity IDJ.Qlide Ac:tiYi:t:l Il31 l.04E+4 Il31 1. 28E+l Il32 3.58E+3 Il32 4.40E+O Il33 1. 60E+4 Il33 2.00E+l Il34 2.02E+3 Il34 2.40E+O Il35 8.08E+3 Il35 1.00E+l

Kr85m 4.4E+2 Kr85 2.1E+3 Kr87 2.6E+2 Kr88 7.8E+2

Xel3lm 5.4E+2. Xe133m 4.4E+3 Xe133 6.7E+4 Xel35m 1. 3E+2 Xel35 2.2E+3 Xel38 l.6E+2

* From Ref.[l].

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02560

.STONE & WEBSTER ENGINEERING CO-RATION CALCULATION SHEET

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UR(B)

CALCULATION IDENTIFICATION NUMBER

CALCULATION NO.

010 - 0

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PAGE 38

8.0 Results ana Conclusions

The calculated control room doses from the airborne source due to a RCP Locked Rotor Accident for the modified control room ventilation design are summarized below. The lOCFRlOO and GDC 19 dose limits are also listed for comparison:

Thyroid

Calculated CR Dose with Selection of Better Intake*

7.5 Rem

Whole Body 0.21 Rem

Beta 2.8 Rem

GDC 19 & Equivalent Dos ~ .... _ __..LL.j,i...,.muio...it..___

30 Rem

5 Rem

30 Rem

* Automatic selection of the better intake with only one unit EACS operating.

·' - •6010.65 • ~I UNI: & WI:~::> I l:H l:Nl:i1NEERIN9JHP~RA TION CALCULATION SHIJllll' CALCULATION IDENTIFICATION NUMBER J.O.OR. W.O.NO.

02550

DIVISION & GROUP

UR(Bl

CALCULATION NO.

010 . 0

OPTIONAL TASK CODE PAGE 39

N/A

Calculated CR Dose with ** Pre-existing Emergency Mode

GDC 19 & Equivalent Dose Limit

Thyroid 17 Rem 30 Rem

Whole Body 0.86 Rem 5 Rem

Beta 11 Rem 30 Rem

** Assumes worst case CR intake but that the CR EACS for both units are available.

It is concluded that the calculated doses are within the allowable limits for the RCP Locked Rotor Accident.

The process safety limit for the control room intake monitors is determined in Appendix A based on the more stringent limit of the following two criteria:

(1). The control room activity concentration shall be less than 1 Derived Air Concentration (PAC} listed in 10CFR20, Appendix B, Table I, Column 3.

(2). The dose rate contributed by the airborne activity shall not exceed the radiation zone limit of the control room. The control room is designated as radiation zone I with maximum dose rate of 0.25 mr/hr according to FSAR sect.12.1.

The process safety limit is determined to be 4E-5 µCi/cc (Xe-133}. The actual monitor setpoint shall include loop allowance and a safety margin.

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• e· STONE & WEBSTER ENGINEERING CORPORATION

•5010.65 CALCULATION SHEET

CALCULATION IDENTIFICATION NUMBER

J.O.OR W.0.NO. DIVISION & GROUP CALCULATION NO •

002 - 0

OPTIONAL TASK CODE

NA

PAGE 4

02560 UR(B)

1.0 Objective

The objective of this calculation is to determine the radiation doses, at the Salem Generating -- _ · _.control room following postulated Fuel Handling Accident in the Fuel Handling Bldg. The calculation assumes a simultaneous Loss of Offsite Power (LOOP) following the Control Room (CR) isolation signal generated by µie CR intake radiation monitors, with the subsequent delay in switching from the normal operation mode to the emergency

· operation mode of the control room ventilation system. The calculation considers two CR Emergency Ventilation operation scenarios:

,. The first scenario utilizes the automatic selection capability of the radiation monitors to select the less contaminated CR intake. In addition, it asstimes that only one Unit's CR emergency ventilation system is available.

,. The second scenario assumes that the CR emergency ventilation is already in operation at the time of an accident. This scenario assumes two train operation.

Additionally, the calculation considers two Fuel Building ventilation operation scenarios:

,. The first scenario assumes that the Fuel Bldg. ventialation exhaust is administratively aligned through the Fuel Bldg. filters prior to fuel movement (i.e., takes credit for the Fuel Bldg. Exhaust filters for the duration of the accident).

,. The second scenario assumes that the Fuel Bldg. Ventilation exhaust filters are bypassed for the duration of the accident.

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• • ••• STONE & WEBSTER ENGINEERING COR ORATION .. 5010.65 CALCULATION SHEET

CALCULATION IDENTIFICATION NUMBER

J.O.OR W.O.NO. DIVISION & GROUP CALCULATION NO.

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NA

PAGE 7

02560 UR(B)

3.0 Assumptions

I.

2.

3.

3.

Exhaust Lambda (.l) for FHA in Fuel Bldg ........ 60 hr·1

Design Lambda of the Fuel Pool Sweep Gas System.

Activity release Path

FHA in Fuel Building

Fuel gap activity is released to the fuel pool. Noble gas and unscrubbed iodine escape to the air space above the pool where they are exhausted by the fuel pool sweep gas system and released via the main Unit vent.

Fuel Building Exhaust Filter Efficiency

90% Inorganic 70% Organic

Ref.[1]

Ref.[1]

Ref.[1]

The actual fuel building filter efficiency for organic iodine is greater than that stated above, however, for conservatism, the filter efficiency value for organic iodine provided in Safety Guide 25 is followed in lieu of using the actual technical specification · efficiency.

It is expected that the filter efficiency of inorganic iodine would be greater than the value presented above given that the filter is so effective in cleaning up organic iodine, however, for conservatism, the filter efficiency value for inorganic iodine provided in Safety Guide 25 is followed. _

Delay time for the CR pressurization mode to be fully operational - 48 seconds

Ref.[2]

The normal intake d8.mper closure time is assumed to be 20 seconds (Ref.[2]). The Loss Of Offsite Power (LOOP) is assumed to occu.r at the time the dampers are fully closed and the power· to the EACS fans are lost. At the LOOP, the Diesel Generators start and it takes 13 seconds(Ref.[2]) for the DG's to become fully operational and the power is delivered to the EACS fans. The EACS fans are assumed to take 15 seconds (Ref.[2]) to gain full speed and the control room is considered fully press~ed at this .time. Therefore, the total delay time from the issuance of the control room radiation monitor signal until the control room is in emergency pressurized mode is the sum of normal intake damper closure time (20 sec), the Diesel Generator speedup time (13 sec), and the EACS fans speedup time (15 sec) for a total of 48 seconds.

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A5010.65 • STONE & WEBSTER ENGINEERING CORPORATION

CALCULATION SHEET

CALCULATION IDENTIFICATION NUMBER

J.O.OR W.O.NO. DIVISION & GROUP CALCULATION NO. OPTIONAL TASK CODE

02560 UR(B) 002 - 0 NA

4. PARAMETERS ASSUMED FOR MONITOR RESPONSE TIME

Time constant - Table 6-1 ofreference[3] Response data - 2.7E7 cpm/(µCi/cc) for Xe-133

l.2E8 cpm/(µCi/cc) for Kr-85

The monitor specific time constants are not available at this time. The values in Table 6-1 ofref.[3] for SE RM-2000 smoothing algorithm with filter constant equal to 6 are used. The specific detector response data are also not available at this time. The Calculation conservatively uses 50% of the values given in Table 2 of SE calibration report E-255-1332 [Ref.4] for a typical

· beta in-duct detector RD-25A in a 55 gallon drum.·

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[Ref.2]

[Ref.3] [Ref.4]

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•5010.65

lNE & WEBSTER ENGINEERING CORP. TION CALCULATION SHEET

CALCULATION IDENTIFICATION NUMBER

J.O.OR W.0.NO. DIVISION & GROUP CALCULATION NO.

002 -0 02560 UR(B)

4.0 Data

1. Total gap activity released to pool from the rods that failed (curie)

1-131 5.86E4 1-132 2.81E4 1-133 6.33E2 1-135 3.53E3 Xe-131m 8.895E2 Xe-133 8.096E4 Xe-133m 9.248E2 Xe-135 l.234EO Kr-85 2.276E3

Value§ B~~Q QQ: Activity Values based ori: Thermal Power= 3600 Mwt Number of Damaged Assemblies= I Enrichment = 4.5% Decay Time = l 68hr Radial peaking factor = 1. 7 Fraction of core noble gas and iodine activity in gap: 1-131(12%); Kr-85(30%); All others (10%)

2. Pool Decontamination Factors

HalQgen~ Inorganic : 133 . Organic : 1 Overall : 100

Noble G~ All : 1

Values Based on: Minimum water depth for scrubbing = 23 ft

3. Iodine chemical form before scrubbing

99.75% Inorganic 025% Organic

4.

OPTIONAL TASK CODE

NA

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•5010.65

.ONE & WEBSTER ENGINEERING CO.ATION CALCULATION SHEET

CALCULATION IDENTIFICATION NUMBER

J.O.OR W.O.NO. .DIVISION & GROUP CALCULATION NO.

002 - 0

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NA 02560

5.

6.

7.

8.

UR(B)

Control Room Breathing rate - 3.47E-4 m3/sec

Control Room x/Qs (Atmospheric Dispersion Factors):

Before Isolation (Unit 1 Main Vent, Unit 1 CR Intake) - s/m3 0-2 hr 1.72E-3 2-8 hr l.22E-3 8-24 hr 1.03E-3 1-4 day 7.13E-4 4-30day 4.19E-4 ·

After Isolation (Unit 1 MainVent, Unit 2 CR Intake) - s/m3 0:..2 hr 8.90E-4 2-8 hr 6.35E-4 8-24 hr 5.36E-4 1-4 day 3.72E-4 4-30day 2.20E-4

CONTROL ROOM PARAMETERS - Modified design

*Control room pressure envelope volume: 81,420 ft3

*Normal unfiltered air intake rate: 1200 cfm

* Filtered emergency makeup flow- 2500 cfm * Total unfiltered inleakage- 60 cfm (10 cfm from ingress/egress; 50 cfm from ductwork leakage)

* Filtered recirculation flow rate 5500 cfui - one EACS fan operation 13,500 cftn - two EACS fans operati

' . .. ' ,... . " ( .. . e •5010.65

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02560 UR(B)

8.0 Results I Conclusions

CALCULATION IOENTIFICA TION NUMBER

CALCULATION NO.

002 -0

OPTIONAL TASK CODE

NA

PAGE 19

The calculated doses (rem) at the Salem Generating Station·. a postulated Fuel Handing Accident in the Fuel Building are:

. control room from

CONTROL ROOM

CASE 1 : Selection of Favorable IntakeO

Filtered Release Unfiltered Release

Thyroid

5.33 35.5

CASE 2: Pre-Existing Emergency Mode@

Filtered Release Unfiltered Release

0.69 3.90

Whole Body &.tg

0.16 0.16

0.32 0.26

1.92 1.92

3.87 3.11

0 Values reflect automatic selection of the control room favorable intake with only one unit EACS operating. @ Assumes worst case control room intake but that the CR EACS for both units are operational .

The exposure guideline in the control room set forth in I OCFR50 General Design Criteria 19 is 5 rem to the Whole body or its organ dose equivalent (accepted as 30 rem to the thyroid from inhalation and 30 rem beta from submersion). The calculated doses in the control room, assuming the releases from the Fuel Building are filtered, are well within the 1 OCFR50 exposure guidelines. However, if the Fuel Bldg. releases are not filtered the calculated dose to the thyroid . .