ML20207H201

Safety Evaluation Supporting Amend 19 to License DPR-21

ML20207H201
Person / Time
Site:	Millstone
Issue date:	08/18/1988
From:	Office of Nuclear Reactor Regulation
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ML20207H180	List: ML20207H176 ML20207H189 ML20207H201
References
NUDOCS 8808240394
Download: ML20207H201 (4)

Text

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SAFETY EVALUAT4ON BY THE OFFICE OF NUCLEAR REACTOR REGULATION  !

1 RELATED TO AMENDM_ENT NO.19 TO FACILITY OPERATING LICENSE NO. DPR-_2_1 MRTHEASTNUCLEARENERGYCOMPANY l MILLSTONE NUCLEAR POWER STATI0h,. N .

UNIT NO. 1 DOCKET NO. 50-245 ,

l 1.0 I_NTR_0 DUCTION ,

By application for license amendnent dated December 22, 1986, Northeast Nuclear Energy Company, et al. (the licensec), requested a change to the Millstone Unit 1 Facility Operating License, DPR-21, to change the expiration date of the license from May 19, 2006 to October 6, 2010.

2.0 DISCUSSION

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Section 103.c of the Atomic Energy Act of 1954 states that a license is to be issued for a specified period not to exceed 40 years. Title 10 CFR 50.51 specifies that each license will be issued for a fixed period of tinee not to exceed 40 years from the date of issuance. The currently licensed terin for M111 ster e Unit 1 is 40 years connencing with the issuance of the construction pemit which was on May 18, 1966. Accounting for the time that was required for plant construction, this repitsents an effective operating license term of  !

approximately 36 years. Consistent with Section 103.c of the Atomic Energy  :

Act and Section 50.51 of the Comission's regulations, the licensee, by the i December ??, 1986 application, seeks an extension of the operating license term for Millstone Unit I so the fixed period of the license would be from the date of the operating license issuance, i 3.0 EVALUATION The NRC staff has evaluated the safety issues associated with issuance of the proposed license anendinent which would allow approximately 4 additional years l of operation. The issues addressed consist of additional radiation exposure 1 to the licensee's operatin0 staff, impacts on t% off-site population, and the general aging of the plant structures and egr9mt. The impact of additional radiation exposure to the facility operating vf and the impact on the general population in the vicinity of Millstm Unit I are addressed in the NRC staff's Environnental Assesstent dated 8808240394 880818 i PDR ADOCK 05000245 P PDC

3.1 ,P_lant Structures and Systems The licensee's request for extension of the operating license is based in part, on the detennination that a 40-year service life was considered during the design and construction of the plant. This does not mean that sone components will not wear out during the plant lifetire. Rather, design features were incorporated which provide for inspectability of structures, systems and equipment. In addition structures, systents and components are required by the Technical Specifications to undergo routine surveillance to assure that there is a high degree of confidence that they will perfonn their safety functions when required.

Millstone Unit 1 Technical Specification (TS) 3.13 requires the licensee to raintain an inservice inspection (ISI) program for ASME Code Class 1, 2 and 3 con:ponents and an inservice test (IST) program for ASEE Code Class 1, 2 and 3 pun'ps and valves. These programs are necessary to assure the continued operability ard integrity of systems important to plant safety. The TS 3.13 requirerents further specify that the above programs comply with the applicable Code and addenda as required by 10 CFR Section 50.55a(g) except where the NRC staff provides written relief per 10 CFR 50.55a(g)(6)(1).

Required revisions to the ISI and IST programs will be issued throughout the lifetine of the facility and the reviews of the revisiens will be conducted independent of the issuance of this license amendrrent review.

Aging analyses have been performed for all safety

• elated electrical equiprent in accordance with 10 CFR 50.49, "Environmental quaiification of electrical equiper+nt inportant to safety for nuclear power plants," identifying qualified lifetimes for this equipaent. These lifetires are incorporated into plant equipnent maintenance and replacement practices to ensure that all safety-related electrieel equipnent remain qualified ard available to perfonn their safety functions regardless of the overall age of the plant. Our letter and Safety Evaluation dated March 20, 1985 provides our approval concerning the licensee's program for environmental cualifications of electrical equipnent.

3.2 Reactor Pressure Vessel The reactor pressure vessel (RFV) was designed for 40 years of operation at full power (2011 MW thertnal) with a plant capacity factor of 80%, which is equivalent to 32 Effective Full Power Years (EFPY). The RPV contains a nunber of in-vessel radiation capsules that are periodically withdrawn, and their contents tested, to assure that the RPV mhterials will continue to behave in a ductile fashion under expected operating conditions. The capsule withdrawal schedule is given in TS 4.6.B.5 and assures compliance with 10 CFR Part 50, Appendix H, over 32 EFPY. Thus far, a single capsule has been withdrawn and tested. License Amendment No. 9 contains the NRC staff's evaluation of the licensee's analysis of the capsule.

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Technical Specifications 3/4.6 contains temperature / pressure limits for the reactor coolant system in accordance with 10 CFR Part 50, Appendix G. The original limits in the TS were revised in License Amendment 9 issued on August 20, 1987. We expect that the licensee will continue to update the limits of TS 3/4.9 over the lifetime of the facility.

3.3 ALARA Measures In 1977, the licensee instituted a fomal ALARA program at Millstone Unit 1.

This program contains a number of reasures intended to minimize occupational doses consistent with ALARA considerations. One of these reasures is the use of decontamination prior to work on major components to reduce component dose rates. In 1984. Millstone Unit 1 perfomed a partial systeib decontaminaticn of the reactor recirculation system. This related in a net dose savings of 1300 person-rems on pipe repair and other drywell work perfonned following the system decontamination. Millstone Unit 1 perforned a second chemical decontamination on the recirculation system piping in 1987. Also in 1987, the licensee tested and implenented a zine injection process to reduce radionuclide retention on coolant component surfaces'. Other dose reduction ineasures used at Millstone Unit 1 include use of mockup training, remote tooling and inspection techniques, and use of special tooling and robotics. In order te keep track of occupatirnal radiation doses expended at Millstone Unit 1, the licensee began using a copputerized dese trackirg system in 1979. This system, which is used to track doses and man-hours by system / component / job, provides a good historical dose data base for trending job specific doses and for providing pre-job dose estimates. The reasures 1isted above, which will continue to the end of plant life, including the proposed extension, provide assurance that occupational doses will satisfy ALARA considerations throughout the period of operation.

In addition to the ALARA measures just described, the licensee is actively seeking new nethods to reduce total person-rem dose. The licensee's Exposure Reduction Initiative Program, which was implemented in 1986, consistt of several short-tern, initiatives which are part of this program are scheduled to be achieved in the 1987-1988 time frane, while the seven long-tem initiethes in this program have a completion date in early 1990's. Implementation of the Exposure Reduction Initiative Program should result in lower overall dose rates and lower collective doses at Millstone Unit 1.

As stated above, the licensee instituted an ALARA program in 1977 and an Exposure Reduction Initiative Program in 1986. The overall responsibility for the licensee's Corporate ALARA program lies with the Senior Vice President.

Nuclear Engineering and Operations (NEO). However, it is the responsibility of all NEO management and supervisors to ensure that their staff, their consultants, and their contractors are informed and comply with the licensae's Radiation Protection Program requirerents. There is routine managenent involve-ment in station ALARA concerns. Station ALARA goals are directly related to goals established by the corporate Radiological Assessment Branch. Corporate supplies health physics supervisors to the plant to' assist and oversee the

, station health physics staff during outages. Worker involvenent in minimizing deses is encouraged through worker initiatives and worker input to ALARA feedback reports. The licensee should continue to encourage worker and contractor awareness at the grass roots level of ALARA by making dose reducticn an integral part of design, installation, and maintenance at M'llstcne Unit 1.

3.4 Dos _e Assessment The staff has evaluated the occupational dose data from Millstone Unit 1 for the period from 1972 (startup) through 1987 and compared it with the BWR average for the same period. The cumulative average yearly dose for all U.S.

BWRs over this 16-year period has been approxinately 770 persons-rems. The everage yearly dose for Millstone Unit 1 over this same 16-year period has been approximately 1025 person-rems / year, or about 33 percent above the national average for BWRs. HoNever, since 1983, the yearly collective dose at Millstone Unit I has decreased markedly (the average yearly occupational dose for the five-year period from 1983-1987 for Millstone Unit No. I was 504 person-rems). In an attempt to ensure that this trend continues, the licensee, in 1986, established a three-year average dose goal of 570 person-rems / year to be realized at Millstone Unit 1 by 1990. This three-year averaged cunulative dose will be revitt d downwards on an annual basis as Villstone Unit 1 improves its perfonrance. Mraging the dose over a three-year period enables the licensee to more efrectively reduce person-rem by permitting nore up-front ident'fication of high person-rem jobs and allowing better planning. A plot of the three-year rolling dose averages for Millstone Unit 1, extrapolated to the 1988-1990 time period, shows the three-year averaged dose declining to the 570 person-rems / year dose goal by 1987. The three-year averaged dose for the most recent three-year period (1985-1987) of 481 person-reras/ year was, indeed, well below the three-year averaged dose goal of 570 person-rems / year set for Millstone Unit 1. The licensee plans to maintain the annual dose at Millstene Unit 1 at 570 person-rems / year or less through increased ALARA awareness, and successful inplementation of the Exposure Reduction Initiative Program.

3.5 Summary of Fjgn3s_

Based upon the above, we find that extension of the operating license for i Millstone Unit 1 to allcw a 40-year service life is consistent with the safety i analyses for Millstone Unit I and that the Contrissicn's previous safety  !

findings are not changed. All issues associated with plant systems and '

equipnent, including aging and changes in RFV fracture toughness properties have been addressed and are acceptable for 40 years of operatien.

4.0 ENVIRONMENTAL CONSIDERATION

A Notice of Environmental Assessnent and Finding of No Significant Impact  :

relating to the proposed extension of the Facility Operating License termination date for Millstone Unit 1 was published in the Federal Register l on August 4, 1988 (53 FR 29401).

5.0 CONCLUSION

We have concluded, based on the considerations discussed above, that (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such activities will ,

1 be conducted in compliance with the Consnission's regulations, and the issuance of the anendrent will not be inimical to the common defense and security or to the health and safety of the public.

Dated: August 18, 1988 Principal Contributor:

M. Boyle and C. Hinson

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