HBL-97-009, Provides Addl Justification to Support TS Change Request Contained in LAR 96-02 ,re Establishment of Radiological Effluents Control Program & in Response to 970416 Telcon

Provides Addl Justification to Support TS Change Request Contained in LAR 96-02 ,re Establishment of Radiological Effluents Control Program & in Response to 970416 Telcon

ML20141A985
Person / Time
Site:	Humboldt Bay
Issue date:	06/12/1997
From:	Rueger G PACIFIC GAS & ELECTRIC CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GL-89-01, GL-89-1, HBL-97-009, HBL-97-9, NUDOCS 9706230234
Download: ML20141A985 (4)

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, ' Pacific Gas and Electric Company 245 Market Street, Room 90/-N98 Gregory M Rueger San Francisco, CA 94105 Senor Vice President and jNIh8 c o er neration P.0 Box 770000 San Francisco, CA 94177 415/973-4684 Fax 415/973-2313 June 12,1997 PG&E Letter HBL-97-009 U.S. Nuclear Regulatory Commission ATTN: Doccment Control Desk Washington, D.C. 20555 Docket No. 50-133, OL-DPR-7 I

Humboldt Bay Power Plant Unit 3 i Respnnse to NRC Request for Additional Information on Revision of Technical I

, Spacifications to incoroorate 10 CFR 50. Accendix I Reauirements and Relocate  ;

Radiological Effluent and Radiological Environmental Monitoring Technical i 4

Specifications in Accordance with Generic Letter 89-01

Dear Commissioners and Staff:

This submittal provides additional justification to support a Technical Specification change request contained in License Amendment P"uest (LAR) 96-02, December 9,1996, regarding establishment of a radiological effluents control program. It is being provided in response to a verbal request for additional clarification presented to PG&E during an April 16,1997, y teleconference between PG&E staff members and the NRC's Project Manager 2

and LAR technical reviewer.

PG&E Letter HBL-96-027, dated December 9,1996, submitted LAR 96-02 requesting an amendment to Facility Operating License No. DPR-7 for Humboldt .

)f Bay Power Plant (HBPP) Unit 3. The LAR proposed to incorporate the requirements of 10 CFR 50, Appendix 1, into the Radiological Effluent Technical i Specifications (RETS) and to relocate the controls and limitations on RETS and radiological environmental monitoring (currently in the Technical Specifications) to the Offsite Dose Calculation Manual (ODCM) and Process Control Program (PCP).

. Insert 4, provided in LAR 96-02, included a new Section F to be inserted into the Administrative Controls contained in Section Vil of the Technical Specifications.

The new Section F contained a requirement to establish a program conforming with 10 CFR 50.36a for the control of radioactive effluents and for maintaining the doses to members of the public from radioactive effluents as low as-reasonably achievable (ALARA).

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.U.S. Nuclear Regulatory Commission i ' June 12,1997 4 Page 2 i

i 5 Specifically, Insert F.7 stated:

h Limitations on the dose rate resulting from radioactive material released in j gaseous effluents to areas beyond the SITE BOUNDARY shall be [

] established as follows:

{ a. For noble gases: Less than or equal to an instantaneous dose rate (average over a one-hourperiod) ofless than or equal to 500

mrem /yr to the total body and less than or equal to 3000 miem/yr to

. the skin, and I

l b. For tritium and radionuclides in particulate form with half-lives greater l than 8 days: Less th:n or equal to a dose rate (averaged over a l one-week period) of 1500 mrem /yr to any organ.

4 i Based upon an initial review of LAR 96-02, PG&E has been requested to provide

supplemental justification to support stating that the dose rate in F.7.b for tritium and i

} radionuclides in particulate form is averaged over a one-week period rather than being l determined on an instantaneous basis as stated in F.7.a for noble gases. -

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[ Suoolemental Justification

! The dose rate proposed in Insert F.7.b was stated to be a dose rate averaged over a l' one-week period to provide clarification related to the ability of HBPP Unit 3 to I j- determine a dose rate from radionuclides in particulats form released in gaseous I 4

effluents. This clarification represents a deviation from the guidance contained in NUREG-0133, " Preparation of Radiological Effluent Technical Specifications for Nuclear Power Plants." Section 5.2.1 of NUREG-0133 is written such that restricting

the instantaneous dose rate in unrestricted areas applies to the dose rate from tritium

. and radionuclides in particulate form, as well as the dose rate from noble gases. '

Section 5.1.1 of NUREG-0133 requires that the alarm / trip or automatic control trip l' setpoint for each instrument channel monitoring radioactive material in gaseous i effluents should be set to correspond to a value that represents a safe margin of i assurance that the instantaneous gaseous release limits specified in Section 5.2.1 will I not be exceeded.

1 i HBPP Unit 3 is equipped with a stack gas monitoring system (as required by the current l Technical Specifications) that is provided to determine routine releases of particulate i radioactivity and to provide monitoring and annunciation of nonroutine releases of l

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1 j U.S. Nuclear Regulatory Commission 3

June 12,1997 j Page 3 radioactive noble gases. The stack gas monitoring system consists of a particulate filter ,

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holder, a beta-sensitive detector system, and a sample pump to produce a sample flow l l - controlled at approximately 2 cfm. The detector system is designed to be sensitive to j

! Kr-85 in the stack gas and is capable of having the alarm setpoint set to a value to i ensure that the instantaneous dose rate limit specified in Insert F.7.a is not exceeded.

The stack gas monitoring system does not include a monitor for the particulate filter capable of having an alarm setpoint to ensure that the dose rate limit specified in Insert l F.7.b is not exceeded on an instantaneous basis. Instead, the particulate filters are removed on a periodic basis for laboratory analysis. Even if the stack gas monitoring

! system included a monitor for the particulate filter, NUREG-0133 states in Section 5.1.1 that it is not considered to be practicable to apply instantaneous alarm / trip setpoints to 1 i integrating radiation monitors sensitive to radioactive materials in particulate form and i

{ radionuclides other than noble gases.  !

i i Demonstration of compliance with the dose rate limit proposed in Insert F.7.b will be

performed in accordance with surveillance requirement 2.6.2 of the SAFSTOR Offsite

Dose Calculation Manual, which was included as Attachment D to PG&E Letter

HBL-96-027 submitting LAR 96-02. This requirement will consist of a continuous particulate sample of the gaseous effluents with a weekly analysis frequency. Th's i j methodology is in accordance with surveillane requirement 4.11.2.1.4 contained in NUREG-0473, " Radiological Effluent Technical Specifications for BWR's." j

{L I i The dose rates from radioactive material released in gaseous effluents during the 1 SAFSTOR period for Unit 3 are expected to be well below the limitations proposed in Inserts F.7.a and F.7.b. NUREG-1166, " Final Environmental Statement for ,

j Decommissioning Humboldt Bay Power Plant, Unit No. 3," estimated an annual dose  !

commitment to a maximally exposed member of the public to be less than 0.1

! mrem / year to the skin and the whole body from noble gases and 0.4 mrem / year to any i

organ from tritium and radionuclides in particulate form.

. Evaluation of historical releases of radioactive material released in gaseous effluents

since entering the SAFSTOR period has shown that the calculated dose commitment to

a maximally exposed member of the public has been well below the estimates provided i in NUREG-1166. For example, the reported gaseous effluents for 1996 resulted in a 1 calculated dose commitment of less than 0.005 mrem / year to the skin and the whole body from noble gases and 0.02 mrem / year to any organ from radionuclides in =

particulate form. For 1995, the calculated dose commitment was less than 0.005

{ mrem / year to the skin and the whole body from noble gases and less than 0.01

mrem / year to any organ from radionuclides in particulate form.

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U.S. Nuclear Regulatory Commission June 12,1997 Page 4 Based upon the above information, we believe that the clarification provided in Insert F.7.b stating that the dose rate from tritium and radionuclides in particulate form is averaged over a one-week period is appropriate and that the deviation it represents from the guidance contained in NUREG-0133 is justified. Furthermore, the proposed clarification does not deviate from the methodology currently used to demonstrate compliance with the existing Technical Specification VI.B.3.

Sincerely, S

t/7 w Gregory M. Rueger 1

Subscribed and sworn to before me Attorneys for Pacific Gas

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this Mfh day of June 1997 and Electric Company M Bruce R. Worthington Richard F. Locke

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/ i M (fc s Notary Public Richard F/ Locg f

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? Commisdend10D005 l 6 8 ']k Notory P@As - Colfomi' SAN FRANCSCO COUNT cc: Edgar Bailey, DHS hy<* S **MN Richard F. Dudley Ellis W. Merschoff Kenneth E. Perkins Humboldt Distribution