ML19221A026
| ML19221A026 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 06/08/1976 |
| From: | Vollmer R Office of Nuclear Reactor Regulation |
| To: | Deyoung R Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 7905160502 | |
| Download: ML19221A026 (5) | |
Text
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Distribution S. Hanauer C. Ferrell H. Denton K. Murphy D. Muller L. Soffer R. Voll=er W. McDona.ld, w/o encl.
J. Miller J. Panzarella, w 'o encl.
56 S. Varga P. Snuttleworth, w/o encl.
M 8
L. Boyd Central File K. Kniel NRR Reading Dockat No.: 50-320 H. Silver AAB Reading D. Bunch AAB File DSE Reading Richard C. DeYoung, Assistant Director for Light Water Reactors, DPM THR H MTTE ISLAND UNIT NO. 2 SE2 INPUT PLANT NAME: Three Mila Island Unit No. 2 LICENSING STACR: OL DOCIET NUMBER: 30-320 MILESTOiG NUMBER: 24-31 RESPONSI3LE BRANCH: LWR J2; H. Silver, LPM REQUESTZD COMPLETION DATE: N/A REVIEW STATUS: AAB Enview Completa Attached is the revised Acridat Analysis Branch SER input on Sect $on 15, Tabla 15-1 based on new I/Q values provided by the meteorological section of the Hydrology-Meteorology Branch. Thess values are roughly 50% of those used. in our previous dose calculations. We will require that the applicer suitably ravise the con *ni-at spray additive systan, as pointed out in our earlier mesmo of May 13, 1976. Using the revised manteorological values and the presar e cout'in-c design leak rate of 0.21 per day, we calculata that t' revised spray additive system vill be required to achiave a two hour i2dina does reduction factor of 6.6 in order that the offalta doses for the postulated design basis accident meet the gaf A=14"-s of 10 C71 Part 100. Also includad in this input is Section 6.4, habitability systems, by I. Murphy.
This input was coordinated by Charles Ferrall, Site Analyst, Acetdant Analysis Branch.
Org.nc c,.:v-i by:
Rwened H. Voumer Richard H. Vollmar, Assistant Director for Site Analysis Division of Sita Safety and 4*
Envirnnmetal Analysis Fnelaeure:
Three Mile Island Unit No. 2 SE1 Input
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THREE-MILE ISLAT UNIT 2 SER I' GUT 6.4 Habitability Svstems The emergency ;,rotective provisions of the control room related to the accidental release of radioactivity or toxic gases are evaluated in this section. Relevant portions of the control room ventilation system are described here but are further described and evaluated in Section 9.4.
6.4.1 Radiation Protection Provisions The applicant proposes to neet General Design Criterion 19, Control Room, of Appendix A to 10 CFR Part 50, by use of con-crete shiciding and by installing a redundant if,620 cfm charcoal filtar train to insure a habitable environ =ent within the control room.
In the event of a high radiation signal from the detector located in the air intake structure, the control room supply air is automatically shut off and the charcoal filter set into operation. The filter will process 15,620 cfm of control room air in a fully recirculating node. A second node of e=ergency operation will be used specifically for a LOCA. In the event of a LOCA, a SFAS signal actuates the e=ergency system so that the system vill supply 1000 cfm of filtered outside air to pressurice the control zone. The balance of the filter n/7 120 LC
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. 6.4.1 capacity (14,620 cfs) will process recirculated control room air.
(Cont'd)
This second made was provided to assure limitad infiltration of conenminated air in the event of a long term design basis activity release. Both e=ergency modes can be manually initiated by the operator.
We have performed operator dose calculations assening a design basis LOCA. The resultant doses are within the Criterion 19 guidelines. We conclude that the control room's radiation protection is acceptable.
6.4.2 Toxic Gas Protection Provisions Control room habitability following a postulated toxic gas release is required to ensure that operators can continue to operate the plant. Chlorine has been identified as the only material that, if released, vould pose a potential operator hazard. Provisions such as quick-acting chlorine detectors and self-contained breathing apparatus will be provided to protect the operator against a chlorine release. We have reviewed these provisions against the guidelines of Regulatory Guide 1.95 and have found then to.be adequate. We conclude that the plant's toxic gas protection is acceptable.
n/,%
15.1 Radiological Consecuences of Accidents We have performed an evalustion of the offsite doses resulting from a postulated design basis LOCA, and conclude that, based upon the present containment leak race of 0.2% per day and upon our present evaluation of the containment spray additive system (see section 5.2.3), the offsite doses exceed the guideline values of 10 CFR Part 100.
We will require that the applicant provide a revised spray additive system which is effective in re= oval of iodine in order to meet the guideline values of Part 100. We believe that, with a contain=ent leak rate of 0.2% per day, an overall iodine dose reduction factor of at least 6.6 would be required of the spray additive system to have the offsite doses meet the guideline values of Part 100. We have reviewed and approved contain=ent spray additive systems in the past that have achieved such a dose reduction factor and believe that this is feasible. We will review proposed changes to these syste=s and we will provide our evaluations, as well as revised of f site doses,. as appropriate, in a supplement to this report.
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TA3LE 15-1 POTEiTIAL OF7 SITE OCSES DUE TO DESIGN 3 ASIS ACCIDECS Two Hour Course of Accidents Exclusion Soundary Low Population "one (610 Meters)
(3218 Meters)
Thyroid Whole Body Thyroid Whole Body Accident (Rem)
(Rem)
(Rem)
(Rem)
Loss-of-Coolant Post-LOCA
<1 Hydrogen Turge Dose
<1 Fuel Han' ling 30 2
3
<1 Tube Ruptt re 5
<1 Tube Rup.ure with Icdine.3 pike 78
<1 Steam Line Break 2
<1
<1 Loss of Offsite Power with Coincident Iodine Spike 1
<1 Gas Decay Tank Repture Ne gligible 4
Ne gligible
<1 Rod Ejection
- Case I 51
<1 15
<1 Case II 130 3
15
< 1
- Actual rod ejection 4 __, will not exceed the doses for Case I (releases through the contaire.ent) or Case II (releases through the secordary system).
120 400