ML20236Y530

Responds to 871104 Request for Addl Info on Tech Spec Change 136.Encl Calculation ERS-ATL-86-025, RM-GW-101 Tech Spec Change Justification, Provides Simplified Diagram of Listed Waste Gas Decay Tanks

ML20236Y530
Person / Time
Site:	Beaver Valley
Issue date:	12/02/1987
From:	Sieber J DUQUESNE LIGHT CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
Shared Package
ML20236Y533	List: ML20236Y530 ML20236Y540
References
RTR-NUREG-0472, RTR-NUREG-472 TAC-65106, NUDOCS 8712140068
Download: ML20236Y530 (6)

Text

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~W Telephone (412) 393-6000 .

Nuclear Group P O Box 4 Shippingport, PA 15077 0004 December 2, 1987 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555

Reference:

Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 Additional Information - TAC Item 65106 Gentlemen:

This letter provides our response to your request for additional information dated November 4, 1987 concerning our request for Tr;hnical- Specification Change No. 136. Each item identified in your request is reiterated here followed by our response:

1. In Reference 1 (Attachment. B, p. 1) it is stated that an evaluation of the quantity of radioactive material in the gas surge tank leads to the conclusion that a monitor is not needed for the Waste Gas Decay Tank (WGDT). However, the text does not provide enough information for us to verify Duquesne Lights conclusion. Describa the relationship between the gas surge tank, the WGDT, the monitor for the WGDT, and the radioactive effluent release points. For example, a simple diagram (as opposed to the highly detailed FSAR Figure 11.2~2) would be useful. In particular, state whether there are any radiation monitors that are downstream of the WGDTs and whether these monitors provide alarm and automatic termination of releases from the WGDTs.

Response

The attached calculation package (RM-GW-101 Tech Spec Change s . Justification) provides a simplified diagram (Attachment 3) of the WGDTs, RM-GW-101 and RM-GW-108A&B. RM-GW-101 was only added to the Radiological Effluent Technical Specifications (RETS) to provide an alternate method of determining the tank i activity for surveillance requirement 4.11.1.4 which specified manual sampling of the WGDTs. This was done in anticipation that RM-GW-101 would be made operable. This monitor has been inoperable throughout most of the plant operating history, all attempts to fix the monitor resulted in short-term operation  ;

then failure of the system. This monitor only provides a l I

high-high alarm to alert the operator to divert the waste gas feed to another tank.

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. Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 Additional Information - TAC Item 65106 Page 2

2. In Reference 1 (Attachment S, P. 2, first paragraph), it is stated that:

"This action will ensure the accident analysis value will not be exceeded and in NUREG-0472, Revision 2 Tables 3.3-13 and 4.3-13 do not list a radiation monitor or a sampler ,

flow rate measuring device on the waste gas holdup system."

However, NUREG-0472, Revision 3 (Page 3/4 3-79) and Revision 5 (Page 3/4 3-78) list the following instruments for the Waste Gas Holdup System: noble gas activity monitor; iodine sampler; particulate sampler; effluent system flow rate measuring device; sampler flow rate measuring device; hydrogen monitor; and in some cases an oxygen monitor. In summaty, the staff's position is that the preceding instruments are required for the Waste Gas Holdup System, and that Duquesne Light will need to clarify its request and provide supplemental information to justify the proposed changes.

Response

The attached flow diagram (Att ;hment 3) defines the operation of RM-GW-101 and RM-GW-108A&B. As specified on the flow diagram RM-GW-101 only provides a high-high alarm to alert the operator to divert the waste gas feed to another tank.

RM-GW-108A&B provides a high-high alarm and initiates automatic closure of the WGDT discharge valves to terminate waste gas release. The WGDTs discharge to the Gaseous Waste Process Vent which releases the process gases at the top of the cooling tower. Therefore, Table 3.3-13 and 4.3-13 list the following instruments for the Gaseous Waste / Process Vent System (RM-GW-108A&B): a) noble gas activity monitor, b) particulate activity monitor, c) system effluent flow rate measuring device (FR-GW-108) and d) sampler flow rate measuring device. In addition, specification 3.11.2.6 provides limitations on explosive gas mix'ures t concerning oxygen and hydrogen concentrations in the waste gas holdup system.

3. In Reference 1 (Attachment B, Page 2, first paragraph),

Duquesne Light stated that:

"With RM-GW-101 in operation , no additional information and no increase in the level of safety is provided, therefore, deleting this monitor from the technical specifications will not affect the probability of occurrence or the consequences of an accident previously evaluated."

. Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 Additional Information - TAC Item 65106 Page 3 The rationale that the dose criteria of 10 CFR 100 are met without the monitors is not a sufficient reason for removing the monitors. Other regulations such as 10 CFR 20, Appendix I of 10 FR 50, and General Design Criteria 60 and 64 of Appendix I of 10 CFR 50 are also applicable, but are not addressed in the submittal.

a. Provide the basis for Duquesne Lights assertion that "no additional information and no increase in the level of safety is provided..." by RM-GW-101.

Response

RM-GW-101 was only added to the Radiological Effluent Technical specifications to provide an alternate method of determining the tank activity for surveillance requirement 4,11.1.4 which specified manual sampling of the waste gas decay tanks in anticipation that RM-GW-101 would be made operable.

Other radioactivity monitors satisfy the requirements of 10 CFR 20, Appendix I and GDC 60 and 64, effluent monitor RM-GW-108A & B is located downstream of the WGDTs and monitors the waste gas decay tank release path to provide automatic termination of gaseous release on a high-high activity signal.

b. Describe the reasons (i.e., benefits) for removing the radiation monitor and the sampler flow rate measuring device, as opposed to retaining these instruments.

Presunably there was a reason for initially installing these instruments. Has additional equipment, or changes in procedures made these instruments obsolete or unnecessary? What alternatives have been considered?

Response

RM-GW-101 was installed to provide an alternative method (in lieu of manual sampling) for determining the WGDT activity. This monitor has a history of inoperability and is listed in the Semi-Annual Radioactive Effluent Release Reports as a technical specification monitor that is out of service for greater than 30 days. The present installation poses significant design problems which defeat the proper operation of the system. Numerous costly changes have been implemented to resolve the problems associated with controlling the system pressure drep, regulating f'.ow, calibrating flow instrumentation anc maintaining the compressor operable. Various design modifications have been proposed, however, they are costly to implement, manual sampling is performed to determine the tank activity contents prior to release and tank releaces are monitored by RM-GW-108A&B which provides automatic termination on high-high activity.

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. Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 Addictional Information - TAC Item 65106 Page 4 1

c. Address all applicable regulations in the revised rationale.

Response

RM-GW-101 does not monitor the gaseous waste release path and manual sampling provides determination of tank contents, therefore, this monitor does not provide any information not determined by other means to satisfy the regulations. >

4. In proposed TS 4.11.2.5.1, it is stated that:

"The quantity of radioactive material contained in each gas storage tank shall be determined to be within the above limit at least once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> when radioactive materials are being added to the tank. Performance of this surveillance is required when the gross concentration cf the primary coolant is > 100 Ci/ml.

a. Briefly describe how the quantity shall be determined.

Response

A manual sample of the tank contents is taken and the activity is determined in accordance with manual sampling procedures.

b. Ctate why it is not necessary to determine the quantity of radioactive material in the WGDTs prior to releasing this activity from the WGDTs.

Response

Manual sampling is performed once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> when radioactive materials are being added to the tank, therefore, an activity history for the materials added to the tank is obtained. In addition, RM-GW-108A&B monitor the discharge release path to provide alarm and automatic isolation on a high-high activity signal.

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c. Provide the basis for using a value of 100 l microcuries/mi, rather than some other value, for i determining when surveillance will be required. )i

Response

The attached calculation package (page 3 of 11 item i 2.B) determines the total noble gas activity I (considered as Xe-133) for the BV-1 and BV-2 gaseous waste decay tanks to be 361 uCi/cc and 153 pCi/cc respectively, when corrected for plant grade elevation. The calculation package also specifies (psge 4 of 11 item 2.C.) " NOTE: 100 pCi/ml is a conservative fraction of the most restrictive maximum concentration...".

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, Beaver Valley Power Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 Additional-Information - TAC Item 65106 Page 5 l

L d. Further define the quantity 100 microcuries/ml in terms of activity of a group (s) of radionuclides with half-lives greater than a specified value. i

Response

The attached calculation package (page 9 of 11) provides a list of the source terms from the BVPS-2 FSAR Table 11.3-3 (May 1983) for the design gaseous releases in Curies per year from the Radioactive Gaseous Waste System (Releases of the gaseous waste storage tanks).

Kr-85m = 1.8 Ci/yr Kr-85 = 2.2E4 Ci/yr Kr-88 = 2.6E-2 Ci/yr Xe-131m = 2.4E1 Ci/yr Xe-133m = 4.3E-2 01/yr  !

Xe-133- = 3.9E2 Ci/yr l TOTAL = 2.24E4 Ci/yr For the purpose of this calculation, the noble gas activity is considered as Xc-133. In the calculation for BVPS-1 the maximum corrected concentration was 361 pCi/cc, for BVPS-2 the maximum corrected concentration was 153 pCi/cc. Therefore, for 100 Ci/ml the isotopic activities would be a relative fraction of those stated above.

5. In Reference 1 (Attachment B, Page 1, last paragraph),

it is stated that "We have calculated a Xe-133 maximum expected concentration of 375 microcuries/ml."

Identify the component or system in which the preceding concentration is expected.

Response

The attached calculation package (Page 3 of 11) uses 7,470 Curies for BVPS-1 and 22,200 Curies for BVPS-2 as the maximum' yearly activity that each gaseous waste decay tank could hold. The calculation then considers these yearly release activities as a single release to yield the total noble gas concentration of 375 pCi/cc for BVPS-1 and 160 pCi/cc for BVPS-2.

Beaver Valley Power. Station, Unit No. 1 Docket No. 50-334, License No. DPR-66 Additional Information - TAC Item 65106 Page 6 Based on the above, the proposed changes provide clarification, reflect the results of the calculation package and do not impact the safety of the plant. Therefore, it is requested that the NRC re-evaluate our previous submittal and approve the proposed technical specification changes.

Very truly yours, M

hD. Sieber ice President, Nuclear cc: Mr. F. I. Young, Sr. Resident Inspector (Unit 1)

Mr. J. Beall, Sr. Resident Inspector (Unit 2)

Mr. W. T. Russell, NRC Region I Administrator Mr. P. Tam, Project Manager Director, Safety Evaluation & Control (VEPCO) l

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