0CAN098907, Forwards Addl Info Re OL Extensions on Estimated Charpy Upper Shelf Energy,Occupational Exposures & Spent Fuel Storage Capacity,Per NRC 890825 Request

Forwards Addl Info Re OL Extensions on Estimated Charpy Upper Shelf Energy,Occupational Exposures & Spent Fuel Storage Capacity,Per NRC 890825 Request

ML20248C494
Person / Time
Site:	Arkansas Nuclear
Issue date:	09/27/1989
From:	James Fisicaro ARKANSAS POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
0CAN098907, CAN98907, TAC-66557, TAC-66575, NUDOCS 8910030481
Download: ML20248C494 (10)

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. Arkinnas Pow 1r & Ught CompIny

• O 425 West Capitol P U Box 55; Little Rock. AR 72203 Tel 501377 4000 l

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September 27, 1989 BCAN098907 U. S. Nuclear Regulatory Commission-Document Control Desk Mail Station P1-137 Washington, DC 20555

Subject:

Arkansas Nuclear One - Units 1 & 2 Docket Nos. 50-313 and 50-368  ;

License Nos. DPR-51 and NPF-6 j Request for Additional Information -

License Term Extension for Arkansas q Nuclear One, Units 1 and 2 J (TAC Nos. 66557 and 66575) l i

Gentlemen:

1 In your letter dated August 25, 1989, (OCNA088917) you requested that AP&L )

respond to three questions concerning the effects of the requested operating license extensions on the estimated Charpy upper shelf energy for Unit 1, the estimated occupations' exposures, and the spent fuel storage capacity for each unit. Attached are your questions followed by our responses. If -4 you have any further questions please call. I Very truly yours, w ;fYme J. J. Fisicaro  ;

Manager, Licensing JJF/MCS/1w ~!

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Question 1: The staff has independently estimated that the Charpy upper shelf energy will be reduced to a level below 50 foot pounds (per Regulatory Guide 1.99, Rev. 2) by the end of the current operating licensing term for ANO-1. Please provide a plan to demonstrate that the reactor vessel beltline materials will meet the requirements in Appendix G of Section V.C. of 10CFR Part 50 for ANO-1 for the current license term as well as for the extended term being requested.

Response to Question 1:

y By letter dated May 11, 1989 (ICAN058906), AP&L submitted Technical Report BAW-2075. The report describes the results of the examination of the fourth capsule (ANI-C) of the AND-1 reactor vessel surveillance program (a part of the B&W Integrated Reactor Vessel Surveillance Program, BAW-1543A). The objective of the program was to monitor the effect of neutron irradiation on the tensile and fracture toughness properties of the reactor vessel materials by the testing and evaluation of tension and Charpy impact specimens. The program for ANO-1 was developed and furnished by B&W as described in BAW-10006A, Rev. 3, and conducted in accordance with BAW-1543A, Rev. 2. This program was planned to monitor the effects of neutron irradiation on reactor vessel materials for the 40 year design life of the reactor pressure vessel. The program was designed in accordance with the requirements of 10CFR50, Appendix H and ASTM Specification E185-73.

The capsule received an average fast fluence of 1.46X1018 n/cm2 (E>1.0 MeV).

Based on the calculated fast flux at the reactor vessel wall, an 80% load factor, and the planned fuel management, the projected fast fluence that the ANO-1 reactor vessel inside surface will receive in 40 calendar years of operation is 9.75x1028 n/cm2 (E>1 MeV).

The method of Regulatory Guide 1.99, Rev. 2, predicts a decrease to below 50 ft-lbs for the controlling weld metal at the vessel inside wall. However, using surveillance data and the prediction techniques presented in BAW-1803, it was calculated that none of the reactor vessel material (including the most limiting weld metal) upper-shelf energies will decrease to below 50 ft-lbs during the vessel design life. The uncertainties of the procedures used to evaluate the materials' upper-shelf energies necessitated that a fracture analysis be performed on the most limiting weld metal. This low upper-shelf elastic plastic toughness analysis of the controlling weld in the ANO-1 reactor vessel is provided in Section 9 of BAW-2075. The analysis used the methodology documented in B&W Topical Report BAW-10046A, Rev. 2. The NRC approved the B&WOG analysis procedures in 1986. The low upper-shelf fracture analysis demonstrated that the most limiting weld metal has adequate irradiated toughness properties to assure safe operation to 32 EFPY.

The results of the tension tests indicated that the materials exhibited normal behavior relative to neutron fluence exposure. The Charpy impact data results exhibited the characteristic increase in transition temperature and decrease in upper-shelf energy. These results demonstrated that the current techniques  ;

used for predicting the change in both RT and upper-shelf properties due to {

T irradiation are conservative. The B&W rebmmended operating period was 1

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d extended to 32 EFPY as a result of the fourth capsule evaluation. These new operating limitations are in accordance with the requirements of Appendix G of 10CFR50.

AP&L plans to submit new pressurization, heatup and cooldown limit curves in early 1990 based on the results of the fourth capsule examination.

AP&L also plans to install neutron dosimetry in the ANO-1 cavity in 1990 in order to continue to meet the monitoring requirements of Appendix H. This cavity dosimetry will be consistent with the B&WOG Cavity Dosimetry Program, as described in BAW-1875.

Question 2 In Section 4 of each amendment request AP&L listed operational exposure data. Please update the information in each section to reflect available data for the most recent five year period.

Response to Questions 2:

In reviewing Section 4 of the ANO-1 and 2 amendment requests it was determined that the entire section should be updated. Therefore, an updated copy of Section 4 for ANO-1 and 2 is attached.

Question 3 The spent fuel storage capacity with the current configuration for each ANO unit will be exceeded in the mid-1990's. Please provide information on AP&L's plans to address spent fuel storage based on the extension of the operating license term for each unit.

Response to Question 3:

An initial assessment of AN0's requirements and potential alternatives ,

regarding the continuing need for spent fuel storage capacity was completed in l December of 1988. The major recommendation emerging from this initial 1

assessment was that a more detailed and comprehensive evaluation in the l l 1990-1991 timeframe is required to identify the specific courses of action to I be taken to alleviate the spent fuel storage shortfall and to select the l initial storage technology to be implemented.

There are 63 spent fuel storage locations at AN0-1 and 109 locations at AN0-2 that are physically restricted due to such reasons as heavy loads, access ,

interferences, incore detector and trash stcrage cans, and dummy assembly and j tool storage. The initial assessment acknowledged that prior to implementing any new storage technology, every effort will be made to utilize existing storage capacity. Nevertheless, additional capacity will be required before DOE begins to accept spent fuel at a high-level waste repository.

The initial assessment identified six (6) potential spent fuel storage l alternatives: spent fuel pool rerack, fuel rod consolidation, metal casks, concrete casks, horizontal concrete modules, and modular vaults. Preference  ;

will be given to those technologies for which topical safety analysis reports have been approved by the NRC and that have been demonstrated or implemented at other utilities. Other considerations in selecting an alternative will 2

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. 4 include the likelihood of DOE acceptance of the waste form, any interference with normal operations, and the time required to implement the alternative.

1 It is recognized that there is a possibility that DOE may delay acceptance of spent fuel beyond 2003 resulting in a further increase in required storage capacity at ANO. This will also be considered when selecting from among the storage alternatives. Closely related to this will be consideration of the possibility that DOE may delay acceptance until well into the ANO operating license extension period. The largest impact from this would be associated with the cost of a chosen technology, not the feasibility (e.g., additional metal or concrete casks, etc.)

In summary, AP&L intends to initiate a study in the 1990-1991 timeframe to address the spent fuel storage requirements of ANO-1 and 2. This study will include consideration of spent fuel storage requirements due to extended operation of the units upon receiving license extensions.

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1 SECTION 4 OCCUPATIONAL EXPOSURE (ALARA) EVALUATION AP&L is committed to operate Arkansas Nuclear One in a manner that will not jeopardize Arkansas Power and Light personnel or the public health and safety.

Included in the AND Operating Licenses, is the obligation to maintain the radiation exposure to occupationally exposed personnel at levels which are as low as is reasonably achievable (ALARA) and which are in compliance with the USNRC Regulations, Title 10 Code of Federal Regulations, Part 20. To fulfill l this obligation Arkansas Power and Light Company conducts a Radiological Protection Program that insures compliance with regulatory requirements and the ALARA objective. The primary goal of the Radiological Protection Program is to maintain individual and collective radiation doses to AP&L and contractor employees at ALARA levels through improved operational practices, procedures, and equipment.

In support of the Radiological Protection Prograta, Design Engineering initiates a peer review and an ALARA review of changes or modifications to nuclear equipment and facilities. As part of the ALARA efforts, periodic training has been provided for engineering and ALARA review personnel. State-of-the-art ALARA design techniques that emphasize source reduction and dose reduction during plant modifications are introduced at the training sessions. An individual within Design Engineering with responsibility for coordinating ALARA efforts reviews the ALARA portion of each Design Change Package (DCP) as part of the approval process.

The ANO Radiological Protection Program has been implemented and audited, both internally and externally, with favorable results. A corporate oversight program is in place to review radwaste, source reduction, ALARA, and dose reduction.

G0ALS PROGRAM A Radiation Exposure Goals Program was stated in 1987 to achieve personnel exposure reduction through improved performance of radiological work. The goals are to be established annually. AP&L anticipates the continuation of this program as long as it remains effective or unless a more effective methodology is developed. The following actions are initially being taken to implement this program. As with any dynamic program, these actions will be modified as more experience is gained.

(A) Radiation exposure goals are developed by the AN0 ALARA Coordination and work groups that received significant radiation exposures. Work groups j which used or were responsible for contractor support were also l responsible for developing exposure goals for those contractors.

The ANO ALARA Coordinator works with these assigned individuals to provide data and assistance in the development of goals. Work group exposure is tracked and deviations from the goals are reported to ANO Management.

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These goals and plans of action are developed and reviewed with Departmental Managers to obtain their direction, ownership and approval.

The work group goals are compiled to develop the AND Total Radiation Exposure Goal. AP&L assesses the annual exposure goal effort to determine its effectiveness as an ALARA tool.

(B) Supervisory / management involvement in work activities in radiologically controlled areas has been increased.

(C) Exposure reduction techniques and good radiation work practices are emphasized during radiation worker training. Attention to exposure reduction has been increased through ALARA Awareness Programs.

(D) AP&L has implemented a decontamination and contamination control program for the ANO 1 and 2 Auxiliary Buildings, emphasizing the control of leaks and spills.

(E) ANO management is working to improve communications between Health Physics and other work groups on radiological considerations during work activities, routine operations, and outages.

SPECIFIC ALARA MEASURES Arkansas Power & Light Company has evaluated and implemented numerous ALARA-related changes that have or are expected to reduce occupational exposures. The following are examples of specific measures that have been or are being taken at ANO:

(A) By increasing the use of remote equipment and flexible stabilizers for steam generator tube plugging operations, significant exposure reductions have been achieved. For example, the average exposure per steam generator tube repaired was reduced from 3.2 rem / tube during 1983 to 1.15 rem / tube during 1988.

l (B) Equipment mock-ups are used to train personnel prior to actual repair work being done.

(C) ANO subscribes to the NSSS vendor-specified lithium-borated chemical i control programs for each unit to minimize activity buildup in the reactor coolant systems.

1 l (D) Periodic cleaning of tanks and sumps has been implemented to evaluate its l potential to reduce the quantity of spent resin that must be handled as radwaste, which would reduce the associated worker exposures.

(E) The installation of a Duratek filtration system on Units 1 and 2 has greatly reduced the number of radwaste filter changes and the associated exposure.

(F) The Unit 1 and 2 Auxiliary Buildings have been decontaminated so that most areas will not require anti-c clothing for entry. Over the long-term, this is expected to reduce personnel exposures and the volume of low level radioactive waste.

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(G) ANO has implemented the use of glove bags to maintain much of the Auxiliary Buildings as uncontaminated areas.

(H) A dedicated decontamination section has been added to the ANO staff.

(1) A computerized health physics record system has been installed. The system tracks personnel exposures, produces ALARA reports, and generates-radiation work permits.

(J) Cleanup measures are being taken on each unit to reduce the amount of particulate material within the RCS by using fine filter cartridges.

(K) ANO has begun taking steps in RCS cleanup by way of H 202 treatment at the beginning of its outages.

OCCUPATIONAL DOSE ASSESSMENT The proposed additional years of reactor operation are not expected to increase annual collective occupational exposures to radiation workers. Arkansas Power

& Light Company will continue to comply with NRC guidance and requirements for keeping radiation exposures as low as is reasonably achievable.

Figure 2 presents information on past annual collective exposures at ANO compared to the industry average exposure per reactor. The industry data for 1984.through 1988 are from INPO documents. ANO data reflects operation of both units.

ANO exposures have consistently been below the industry average with the exception of 1983, 1986, and 1988. In 1983, approximately 100 man-rem was-incurred during the installation of extensive modifications and 440 man-rem was due to Unit I steam generator tube repair. The higher than average exposure in 1986 resulted from refueling outages for both units being extended, which permitted additional jobs to be performed during that year. Similarly, refueling outages were conducted on both units during 1988 and additions to the work scope resulted in the higher than average exposure.

Arkansas Power & Light Company has set a long-term exposure goal for 1990 -1994 to be in INP0's Best Performing Quartile (3 year average) of US nuclear units.

Arkansas Power & Light Company will continue to comply with the established Radiological Protection Program and will incorporate on going improvements into that program as appropriate throughout the duration of the operating license.

The Radiological Protection Program is constantly evolving as techniques are perfected, technology is improved, and the work force becomes increasingly proficient in radiation protection practices.

Arkansas Power & Light Company does not expect any increase in the annual collective occupational exposure for the years 2008 - 2014 for Unit 1, or the years 2012-2018 for Unit 2. In fact, meeting the aggressive long-term exposure goals will result in annual exposure reductions.

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AP&L does not anticipate that the relative distribution of exposures among work groups will change significantly. Figure 3 provides an overview of man-rem exposure by job functions, listed by major work group. Data is for the entire site and reflects two-unit operation after 1980.

FUTURE RADIOLOGICAL PROTECTION PROGRAM ENHANCEMENTS Arkansas Power & Light Company is committed to evaluating and implementing (as appropriate) new ALARA measures as they are developed. The company is staying abreast of emerging ALARA concepts through its membership ir. such organizations as INPO, EPRI, NUMARC, and others. Management attention has been focused on ALARA by the AND ALARA Committee and the Nuclear Operations ALARA program, which focuses on increased management attention on ALARA. Technological developments in fields such as the use of remotely operated tools and surveillance equipment, enhanced training of radiation workers, new shielding techniques, advanced computer software programs for waste management applications, and others are being monitored to evaluate their applicability for improvement of the AND Radiological Protection Program.

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