ML18139B425

Forwards Surry Offsite Toxic Chemical Release Analysis, Vol 2 as Followup to 810119 Response to NUREG-0737, Item II.D.3.4.Corrective Actions for Toxic Chemical Releases Encl

ML18139B425
Person / Time
Site:	Surry
Issue date:	06/30/1981
From:	SYLVIA B R VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	DENTON H R Office of Nuclear Reactor Regulation
Shared Package
ML18139B426	List: ML18139B425 ML18139B427
References
RTR-NUREG-0737, RTR-NUREG-737, TASK-2.D.3, TASK-TM 036A, 36A, NUDOCS 8107020210
Download: ML18139B425 (3)

Text

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• Vepco VIRGINIA ELECTRIC AND POWER COMPANY June 30, 1981 Mr. Harold R. Denton, Director Serial No. 036A PSE&C/LTW Office of Nuclear Reactor Regulation Attn: Mr. Darrell G. Ei~enhut, Director . Docket Nos. 50-280 50-281 License Nos.DPR-32 DPR-37 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D.C. 20555 *

Dear Mr. Denton:

.This letter is in follow-up of our letter serial no. 036 dated January 19, 1981 in response to item II.D.3.4 of NUREG-0737 for Surry Power Station, Units 1 and 2. Our previous letter contained the evaluation and response to all items except the analysis of control room concentrations from toxic chemicals transported within five miles of the station. This analysis was completed by the NUS Corporation and the results have been reviewed and approved by Vepco. Forty (40) copies of NUS report no. NUS-3735, volume II, 11 Surry Offsite. Toxic Chemical Release Analysis, 11 are enclosed as Attachment II. This report indicates that for an accidental rupture of a container of gasoline being shipped on the James River, the maximum concentration of the chemical in the control room may exceed the toxicity limit for that chemical.

The corrective actions for gasoline and fbr~the four chemicals identified in our previous letter are discussed in Attachment 1 to this letter. I to All this a. b. C. d. e. modifications proposed in our previous letter and in Attachment letter will be completed by the following dates: Install a redundant control room bottled air system by 1/1/83. Install a redundant control room isolation dampers in the normal supply and exhaust ducts by 1/1/83. Replace sodium analyzers which utilize dimethylamine gas with sodium analyzers which do not utilize dimethylamine gas by 1/1/83. Install chlorine gas detectors at the control room air intake by 1/1/83. Restrict the storage of hydrazine to the condensate polishing building and the main warehouse by 10/1/81. Please advise if additional information is required.

Very truly yours, B. R. Sylvia Manager -Nuclear Operations

& Maintenance

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• ATTACHMENT 1 CORRECTIVE ACTIONS FOR TOXIC CHEMICAL RELEASES 1. CHLORINE -Chlorine Gas Detectors will be installed at the control room normal air intake. In the event of a rupture of a chlorine tle at the sewer treatment building, the Chlorine Detectors will vide an alarm in the control room. 2. HYDRAZINE

-The Calculation for hydrazine was based on a 55 gallon drum located at the bottled gas storage pad, 58 m. from the control room. Site procedures are being revised such that hydrazine is only stored in the Condensate Polishing Building, 114m from the Control room, and in the main warehouse, 450m from the Control room. The calculation for hydrazine located in the Condensate Storage Building indicates that the maximum concentration in the control room is 0.6mg/m3 (0.46 ppm) compared to a threshhold limit value of l.3mg/m3 (1 ppm) (see CRC Handbook of Chemistry and Physics, 58th Edition).

Therefore the control room operator will not be required to put on self-contained breathing apparatus.

3. DIMETHYLAMINE -Dimethylamine Gas is used by four sodium analyzers in the Turbine Building.

These sodium analyzers will be replaced by a type which does not utilize Dimethylamine Gas, at which time this gas will be removed from the site. 4. CARBON DIOXIDE -The calculation for carbon dioxide indicates a maximum concentration in the control room of 39,000 mg/m3 (22,000 ppm or 2.2 percent) compared to a toxicity limit of 18,000 mg/m3 (10,000 ppm or l .*O percent).

The toxicity limit of 1.0 percent was taken from Table C-1 of Regulatory Guide l .78, yet this table states that the toxicity limits are adapted from Sax's 11 Dangerous Properties of Industrial Materials.

11 According to Sax's 11 Dangerous Properties of Industrial Materials-Fifth Edition 11 (pages 469 and 387), carbon dioxide is an asphyxiant and as such would have a toxicity limit of 33 percent before appreciable symptoms of oxygen de-pl et ion deve 1 op. Since the maximum concentration of carbon dioxide in the control room is 2.2 percent compared to a toxicity limit of 33 percent, the control room operator will not be required to put on self-contained breathing apparatus.

No modification is necessary.

5. GASOLINE -The calculation for gasoline indicates that the buildup of fumes in the control room is at a slow rate: Since gasoline has a low odor threshhold (approximately 60 mg/m3 ), there would be 157 seconds (2.6 min.) warning for the control room operator to manually isolate the control room normal air intake before the toxicity limit is exceeded in the control room. Therefore, the control room operator will not be required to put on self-contained breathing apparatus.

No modification is necessary.

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• v1RG1N1A ELECTRIC AND POWER coMPANY To Mr. Harold R. Denton Attachment 1: Attachment 2: BRS/yem 11 Corrective Actions for Toxic Chemical Releases 11 11 Surry Offsite Toxic Chemical Release Analysis 11 , Report no. NUS-3735, Vol. II cc: Mr. J. P. 0 1 Reilly -NRC Region II SHEET NO. 2