ML20040B837

Forwards Draft Technical Evaluation Rept of Util Response to NUREG-0737 Item II.F.1 Re Accident Monitoring Instrumentation.Util Has Not Provided Equipment & Procedures Necessary to Comply W/Requirements

ML20040B837
Person / Time
Site:	Pilgrim
Issue date:	01/06/1982
From:	Huchton R SIEMENS POWER CORP. (FORMERLY SIEMENS NUCLEAR POWER
To:	Stoddart P NRC
References
RTR-NUREG-0737, RTR-NUREG-737, TASK-2.F.1, TASK-TM NUDOCS 8201260463
Download: ML20040B837 (5)

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E(@N NUCLEAR IDAHO COMPANY, Inc.

P.O. Box 2800 $$

loAHC FALLS. IDAHO B3401. l' ,. -- D 6 January 1982

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• 'l Report for Pilgrim 1 g&g# s t Huch-1-82 s w f(f S P. G. Stoddart U. S. Nuclear Regulatory Conrnission Mail Stop P730 Washington, D. C. 20055

Dear Mr. Stoddart:

Attached for your review is the draft Technical Evaluation Report for the Pilgrim Nuclear Power Station Unit 1 response to NUREG-0737,Section II.F.1, Attachment 2.

As discussed during the telecon meeting on 24 September 1981, the Technical Eval-uation Report was prepared using the format you provided for Arkansas Nuclear One; it addresses the proposed actions by Pilgrim 1 which centinue to deviate from the NRC requirements. Pending notification by the NRC, additions, deletions.or changes to the TER will be incorporated and/or a final TER will be issued.

If you have any questions, please call (FTS 583-2452).

i Sincerely, W)L R. L. Huchton Radiochemistry RLH:aer Attachments

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TEClif1ICAL EVALUATI0ft 0F Tile RESP 0flSE TO ATTACliMErlT 2 0F ITEM II.F.10F flVREG-0737

" ADDITIONAL ACCIDErlT-MONITORIflG IflSTRUMEf4TATION" FOR THE PILGRIM fiUCLEAR POWER STATION UNIT 1 (Docket flo. 50-293) l BY R. L. liUCHT0fl EXXON Nuclear Idaho Company, Inc.

P. O. Box 2800 Idaho Falls, Idaho 83401 l

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! REFERENCES

'4 II.F.1-2 Sampling and Analysis of Plant Effluents

) a) BECo Submittal, A. V. Morisi to D. G. Eisenhut December 15, 1980 i b) BECo Submittal, W. J. Merritt to D. G. Eisenhut, February 27, 1981 -

,' c) BEco Submittal, A. V. Morisi to T. A. Ippolito, October 16, 1981 INTRODUCTION AND BACKGROUND

! Pilgrim 1 proposes to utilize their present iodine sampling system for both i routine and accident monitoring of halogen releases. No modifications to the present system are proposed which would make the system more amenable to sample changeout, transport, and analysis using remote handling techniques to reduce personnel exposures to GDC 19 limits. In the event radiation

! levels around the sampling system and/or from the sample cartridge itself l prevent normal handling and analysis, Pilgrim 1 proposes to estimate the halogen release rates using the gross ganma response of the High Range Noble Gas Monitor. The use of such estimation techniques, which may grossly over-estimate actual iodine release concentrations, could culminate in urinecessary emergency response actions.

i LICENSEE'S POSITION Boston Edison Company (BECo), in their letters dated 15 December 1980, 27 February 1981, and 16 October 1981 proposes the continued use of their present iodine sampling system for both routine and accident monitoring of j radiolodine releases from the Unit 1 Pilgrim Nuclear Power Station. BECo states " . . . the normal iodine collection devices would be retrieved and analyzed provided access to the sampling location is available and the

sarrpling device itself does not result in a dose rate to the operator which is prohibitive." In the event such accident conditions do occur Pilgrim 1 proposes to estimate halogen release rates from the noble gas gross activity monitors. Using a derived relationship between detector response and noble gas and halogen release rates, the licensee states it is possible to estimate conservative halogen release rates of between 104 and 109 pCi/sec. BECo con-

! tends the estimation technique would certainly result in a higher estimate

{ of halogen release rates than are actually occurring.

DESIGN BASIS OR REVIEW CRITERIA The design basis and review criteria for this item are contained in II.F.1 Attachment 2 of NUREG 0737, pages 3-100 through 3-101.

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TECHNICAL EVALUATION NUREG-0737,Section II.F.1-2, requires a licensee to provide the capability to 1) continuously collect a thirty minute iodine / particulate sample of gaseous effluents containing up to and including 102p Ci/cc, 2) remove the sample from the coller. ting we:.nanism, 3) transfer the sample to an analytical facility, 4) measurc or analyze the accumulated iodine / particulate, and 5) perfonii all the above without exposing any individual to a radiation dose in excess of 5 rem to the whole body or 75 rem to the extremities. To aid in the development of the licensee's ability to meet the requirements for accident nonitoring, a design basis shielding envelope was recommended by the NRC for use as a guidelinein determining the system design criteria for sample col-lection, retrieval, transfer, and analysis under accident conditions.

Boston Edison Company (BECo) proposed in their submittal dated 15 December 1980 to utilize their present iodine / particulate collection system to meet NUREG-0737,Section II.F.1-2 requirements. BECo noted its intent to review the current system design and operating procedures and to make any modifications deemed necessary to fulfill this requirement. BECo also noted the installed noble gas monitor could be used to estimate iodine releases should an accident occur at Pilgrim 1 that made the sampling location inaccessible.

In the 27 February 1981 correspondence BECo stated the Pilgrim 1 intent to estimate radioiodine releases using existing noble gas gross activity monitor in the event an accident occurs which makes the sampling location or sampling device itself inaccessible due to prohibitively high personnel dose rates. The proposed method uses a calculated relationship between noble gas detector re-sponse and noble gas and halogen release rates. With the method BECo indicated it is possible to conservatively estimate halogen release rates between 104 and 10'3pCi/sec or 360 to 36,000,000 Ci/hr. BECO contends this method of est-imating the halogen release rates will result in conservative estimates of halogen releases, ie, higher than actual halogen releases, as it assumed in calculating the estimated releases that the ratio of noble gases to halogens in the core and the airborne effluent pathways are the same. The nomograms to be used at Pilgrim 1 for estimating the radioiodine release rates and re-sulting offsite dose rates in relation to the noble gas monitor readings were submitted in the 16 October 1981 letter.

From the content of the BECo submittals and their position taken to estimate halogen releases in the event of an accident prohibiting sample retrieval and analysis, no modifications have been made which will bring Pilgrim's ex-isting radiciodine/ particulate sampling system into compliance with the re-quirements of Section II.F.1-2.

ENIC0 agrees the method of estimating halogen releases using nomograms to relate noble gas nonitor responses with halogen releases can provide a rapid and conservative estimate of the radiciodines being released. However, ENIC0

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. 4 does not believe the proposed method of estimating the halogen releases meets the intent of NUREG-0737,Section II.F.1-2. The proposed method can lead to calculated release rates that grossly O mrastimate the r;dio-iodine and particulate releases that are actually occwrir:g due, potentiMly, to very low and/or unknown ratio of halogens to noble gases in the gaseca effluents. The consequences of grossly overestimating radiciodine nieases are highly undesirab e in the wake of the TMI-2 accident. The advantage actual measurements of halogen / particulate releases provide is the pre-vention of unnecessary public concern and/or emergency response actions, such as evacuation of the surrounding populace.

C0fiClfJSIONS_

It is the conclusion of this Technical Evaluation Report that the Boston Edison Company's (BECo) Unit 1 Pilgrim fluclear Power Station has not provided the equipment and procedures necessary to comply with the require-ments of fiUREG-0737,Section II.F.1-2. Instead, the licensee has proposed a technique of estimating radioiodine/ particulate release rates which could grossly overestimate the actual radiciodine release and could result in the needless activation of emergency evacuation plans. In order to comply with the requirements of Section II.F.1-2, the licensee should provide a system for the sampling, sample retrieval, handling, transport, and analysis of particulate and radiciodine samples of plant gaseous effluents under accident conditions. Such a system should be designed so that a 30 minute duration sample of gaseous effluents with particulate and iodine radioactivity con-centrations of 102pCi/cc can be collected, retrieved, handled, transported, and analyzed without exposing any individual to a radiation dose in excess of 5 rem to the whole body or 75 rem to any extremity.