ML20212R228

Forwards Nuclear Engineering Students Comments on Executive Summary of Advanced LWR Util Requirement Document,Per H Denton Request.Comments Represent Obvious Concerns That Moderately Informed Public Would Raise

ML20212R228
Person / Time
Site:	University of New Mexico
Issue date:	04/17/1987
From:	Williams F NEW MEXICO, UNIV. OF, ALBUQUERQUE, NM
To:	Moran D NRC
References
NUDOCS 8704270001
Download: ML20212R228 (7)

Text

4 T ne MM University of New Mexico l DEPARTMENT OF CHEMICAL AND NUCLEAR ENGINEERING l Albuquerque, NM 87131 l Telephone 505: 277-5431 April 17,1987 1 1

David H. Moran MS/216 US Nuclear Regulatory Commission Washington, DC 20555

Dear Mr. Moran:

Harold Denton requested input on the Executive Summary of the Advanced Light Water Reactor Utility Requirement Document. I have collected the opinions of 15 Nuclear Engineering students.for your information.

Their comments are essentially unedited. In my opinion, they have expressed a number of obvious concerns that a moderately informed public would raise.

Sincerely, Frank Williams, Chairman Chemical and Nuclear Engineering FW/kml enc:

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. Recommendations on the Executive Summary Document of the ALWR Utility Requirements r

Section 1.1 Licensing " reforms" should not assume nuclear power acceptability in the 1990s. Stabilization in political perspectives required to achieve regulatory stablization.

Therefore, national energy policy should be explored,as least as far as demonstrating that the nuclear energy alternative to coal is indeed reliable.

Looking at the past history of the NRC, assuming massive regulatory reform in the near future is way off.

Yes, public utility investment being discouraged by licensing uncertainty is very true. However, assuming significant licensing reforms in place may be too much to hope for.

Section 1.2 Fundamental tests for nuclear power selection by utilities is compromised by public ignorance; particularly investment protection, which presupposes the regulatory climate outlined i in section 1.1.

. These objectives are obvious, the problems surrounding them are not and they are not explained.

Section 1.3 Simplicity is difficult to achieve for a.high power nuclear plant, particularly passive safety characteristics. This may impact the safety issue, where public perception is most volatile. A high design margin will drive up the capital costs.

Simplification and passive operation is a good goal, but this is not reasonable to expect for high power. Some advanced technology may be required.

Other utility personnel than just those in the nuclear power business should be on the Utility Steering Committee.

Section 1.4 Regulatory uncertainty is a function of political and social evolution. Licensing will continue to be challenged at individual construction sites.

Obviously, NRC needs to be involved in such a venture in order for it to succeed. However, it remains to be seen if the NRC really will simplify the regulations as required.

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.Se'ction 2.1 Large reactors are not in demand. Economic size. scale should be optimized for smaller plants. It is unclear whether small

. plants can be demonstrated to be preferable to a larger system.

Again, smaller plants than the average 1100 MWe considered may be needed both for grid requirements and to satisfy the passive operation requirements.

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GiventhecurrentstatusofU.S.energyconsumption,asmall size ALWR (about 600 MWe) is the best choice from simplicity, licensing,etc. points of view.

Section 2.2 Technical targets are appealing, but it sounds like this is a sales pitch. Probability of core damage will not persuade the public - lack of inherent safety (for ANY credible accident) fuels public concern. Reduction of plant response time does not sound more safe.

Why is an ECCS needed for a plant with passive cooling systems?

Probabilities are never stringent enough for the public. The minimum body dose in case of accidents is a good idea, however the possibility of such limits being incorporated into a nuclear plant insurance document is very real. This would not cause a problem with the companies? Also, is this. standardized plant design generic enough to allow each company to add on-their own ideas? Otherwise, this design would never be accepted - some competition is needed and required by law.

Why rely only on ECCS or other backup systems? What about inherent safety design features? Is it possible to simplify the ECCS for a large plant (1350 MWe)?- Need better training for operators in operator / plant interface.

Section 2.3.1 Plant availability time is not based on operating experience.

Incorporation of special features is not consistent with the simple design concept or economic targets. Larger trip margains are unlikely in post-TMI, post-Chernobyl world.

The 92% annual availabilty means there are 58 days shutdown time for every two years. If the refueling only takes 18 days every two years, what are the remaining 40 days for?

(And this does not count the extra 5% unavailability counted towards major repairs.) The trip margains must be approved by NRC.

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18 days in which to cool-down, refuel, test, and increase back to standard operating power is just too fewl As of

. now, it takes 60 days for a standard PWR to do the same, and that includes being under intense pressure to finish. Also, the improved availability requires improvement in maintenance and constant monitoring of parts-wearing. Parts must be changed on a regular basis, not waiting until they need to be replaced. In order to meet the refueling deadline, the critical paths must have easy access and perhaps the secondary paths can be updated while the plant is online.

This entire document seems to think NRC blanket regulations can be obtained for a general design, including higher trip -

points, etc. Good Luck l The 87% average annual availability is too vague - what are the details? 18 days refueling is tough to achieve compared to today's current PWR and BWR designs. Inadvertant plant trips reduced is directly related to regulations.

Section 2.3.2 The sixty year life exceeds time before obsolescence. It seems this is one requirement chosen to drive down annualized capital costs, without regard to the initial expense of longer-life components. Lower energy neutron flux implies a larger core - therefore, greater complexity and expense.

At present, a thirty year lifetime is typical for a nuclear power plant. Is doubling the lifetime reasonable? Why isn't embrittlement limited now by the choice of materials and by reducing the neutron flux?

Looking at how technology has improved so quickly over the last few years, is it reasonable to expect a plant built ten years from now to be economically feasible compared to plants built forty years from now? Other types of power plants are used only as peaking plants after thirty years. Nuclear can never be used this way, so why should they be built to last longer than thirty years?

Sixty year lifetime - will the design make possible additional changes in the plant's-layout without exceeding the time allowed for shutdown?

I Section 2.3.3 Waste reduction is at the expense of newer designs, more monitoring, better compacting. Economic and environmental considerations may work against political concerns on radwaste.

How is the waste to be eleviated? Do we even have the technology? The newer the technology, the less known it is - ,

expenses increase. '

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.,. $i If more than 2500 ft3/ year of shipped radioactive waste is-generated,:or the repository is not open (or temporarily

. shutdown), will adequate storage facilities be.available for storing this waste? For.how long?

Section 2.3.4- Personnel exposure is reduced by inspection and maintenance

-minimization. 'D11s . works against high plant availability, as preventive maintenance has been valuable to the 2

availability' factor in Japenese plants. Use of' remote'.

l' machines also reduces reliability by introducing complexity.

[ Caution: man-rem /yr values'can be " fixed" by counting extra people (i.e., secretaries, employees on vacation, etc.')

To. achieve lower doses, robots must be used. That.will 3

decrease both reliability and simplicity. Since robots are not yet incorporated into nuclear plants, this will-t require more designing and some unknowns. ~ Why introduce an unknown component when the goal is reliability and simplicity?

Section 2.3.5 Standardization trade-off is a possible. compromise in areas where the highest component performance is required; l simplicity at the cost of safety margin. Greater access implies more shielding and higher costs. The sixty year components may become obsolete before1their design life is reached.

1 Human factors and standardization are excellent points.to consider.

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Section 2.4 Low costs not supported in this section, only stated.

As has been asked in history, Where's the Beef?

j Capital costs cannot be reduced if plant runs into~ construction '

delays, manufacturing improvements, etc. Implicitly,.the licensingplaysanimportantroleinthis8%hase.

Section 2.5 Large reliance on the 4 1/2 year construction schedule. This seems unrealistic unless a " tenth plant". hypothetical situation is being examined. Also, unsure of the length of the planning.

stages, which may exceed construction time.

Advanced construction techniques are expensive and could increase capital costs. Must be considered.

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As long as no changes in the NRC regulations were tx> occur and the political situation were tx) remain calm, this could be

. achievable. However, the design would have to be modular so that the pieces could be " snapped" together_at the construction site.

54 months from start of concrete pouring to initial operation?

Perhaps achievable in other countries with less regulation tie-ups. What about labor.disputs, delays, etc.

., This is all the recommendations we have. We needed to see Part II, the Utilities Requirement Document, as many of our concerns might be further addressed there.

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NRH/DONRR - T. Murley..... 1..... 1 i

NRR/PDSNP - P. Leech...... 1.~.... 1 GPA - H. Denton........... 1..... 1 Central Files............. 1..... 1 ACRS...................... 1..... 1 SECY - (Commissioners).... 5..... 5 4

NRC PDR................... 1..... 1 EPRI - John Taylor........ 1 .... 1 4

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